U.S. patent application number 16/535024 was filed with the patent office on 2019-11-28 for structured light projection and imaging.
The applicant listed for this patent is MANTISVISION LTD.. Invention is credited to Martin Abraham, Eyal Gordon.
Application Number | 20190361258 16/535024 |
Document ID | / |
Family ID | 55303109 |
Filed Date | 2019-11-28 |
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United States Patent
Application |
20190361258 |
Kind Code |
A1 |
Abraham; Martin ; et
al. |
November 28, 2019 |
STRUCTURED LIGHT PROJECTION AND IMAGING
Abstract
An optical system, including: (a) an emitter array including a
plurality of individual emitters, wherein each emitter in the
emitter array is operable to emit a light beam which is
characterized by a native beam width; (b) an optical subunit,
operable to transform a plurality of light beams emitted by the
emitter array, wherein each of the transformed light beams is
characterized by an expanded beam width that is wider than the
native beam width of the corresponding light beam and is wider than
a facilitating beam width; and (c) a diffractive optical element
that is capable of diffracting the transformed light beams to
provide light patterns whose angular resolution meets a light
pattern target angular resolution criteria.
Inventors: |
Abraham; Martin; (Hod
Hasharon, IL) ; Gordon; Eyal; (Haifa, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MANTISVISION LTD. |
PETACH TIKVA |
|
IL |
|
|
Family ID: |
55303109 |
Appl. No.: |
16/535024 |
Filed: |
August 7, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14823008 |
Aug 11, 2015 |
10409083 |
|
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16535024 |
|
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|
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62036158 |
Aug 12, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01B 11/2513 20130101;
G02B 27/09 20130101; G06K 9/2036 20130101; G02B 27/0037 20130101;
G03B 21/10 20130101; H04N 5/332 20130101; G02B 27/4233 20130101;
G03B 21/606 20130101; G01C 3/02 20130101; H04N 13/254 20180501 |
International
Class: |
G02B 27/42 20060101
G02B027/42; G06K 9/20 20060101 G06K009/20; G01B 11/25 20060101
G01B011/25; H04N 5/33 20060101 H04N005/33; G01C 3/02 20060101
G01C003/02; H04N 13/254 20060101 H04N013/254; G02B 27/09 20060101
G02B027/09; G02B 27/00 20060101 G02B027/00 |
Claims
1-139. (canceled)
140. An optical system, comprising: an emitter array comprising a
plurality of individual emitters, wherein each emitter in the
emitter array is operable to emit a light beam which is
characterized by a first beam divergence; an optical subunit,
operable to: (a) transform a plurality of light beams emitted by
the emitter array, wherein each of the transformed light beams is
characterized by a second beam divergence that is smaller than the
first beam divergence of the corresponding light beam; (b) to
direct the plurality of transformed light beams onto the
diffractive optical element at different angles of incidence,
resulting in providing of a plurality of light patterns by the
diffractive optical element; and a diffractive optical element that
is capable of diffracting the transformed light beams to provide a
plurality of light patterns.
141. The optical system according to claim 140, wherein the second
beam divergence is lesser than or equal to a facilitating beam
divergence of the diffractive optical element.
142. The optical system according to claim 140, wherein the optical
subunit comprises a plurality of optical elements having a common
optical axis.
143. The optical system according to claim 140, wherein the optical
subunit comprises transforming optical components which are common
to the plurality of light beams.
144. The optical system according to claim 140, wherein the emitter
array and the optical subunit are positioned relative to one
another such that the optical subunit further transforms the
plurality of light beams by deflecting the plurality of light beams
so that the plurality of transformed light beams are projected onto
the diffractive optical element at different angles of incidence,
resulting in providing of a plurality of light patterns by the
diffractive optical element.
145. The optical system according to claim 140, wherein a
combination of the optical subunit and the diffractive optical
element is characterized by a distortion function, wherein the
plurality of individual emitters is arranged in a non-uniform
configuration whose relation to a predefined uniform grid is an
inverse function of the distortion function.
146. The optical system according to claim 140, wherein the
plurality of individual emitters is positioned on a focal plane of
the optical subunit.
147. The optical system according to claim 140, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a light pattern.
148. The optical system according to claim 147, wherein each
provided copy of the light pattern partly overlaps at least one
other provided copy of the light pattern, wherein the light pattern
comprises multiple copies of a repeated subpattern, wherein in each
provided copy of the light pattern at least one subpattern overlaps
a subpattern of at least one other provided copy of the light
pattern generated by light originating from another light
emitter.
149. The optical system according to claim 147, further comprising
an emitter array control system which is configured and operable to
control activation of different subgroups of emitters of the
emitter array, thereby resulting in providing of offset overall
output patterns of the optical system at different times.
150. The optical system according to claim 140, wherein a width of
each one of the plurality of transformed light beams is greater
than a beam width of a facilitating beam of the diffractive optical
element.
151. The optical system according to claim 140, wherein a width of
each one of the plurality of transformed light beams is greater
than the native beam width of the light beam.
152. The optical system according to claim 151, wherein a width of
each one of the plurality of transformed light beams is greater
than the native beam width by at least a factor 3.
153. The optical system according to claim 140, wherein for each
individual emitter of the emitter array there is at least one other
individual emitter of the emitter array positioned at a distance
which is smaller than any beam width of any transformed light beam
out of the plurality of transformed light beams.
154. The optical system according to claim 140, wherein each of the
plurality of individual emitters of the emitter array is a
vertical-cavity surface-emitting laser emitter.
155. The optical system according to claim 140, further comprising
at least one processing unit, and wherein the optical system is
operable to project onto an object at least a part of a structured
light pattern which comprises the plurality of light patterns, and
wherein the at least one processing unit is configured to decode an
image of a reflected portion of the projected structured light
pattern to determine range parameters.
156. A method for projection, the method comprising: emitting a
plurality of light beams, wherein each of the plurality of light
beams is characterized by a first beam divergence; transforming the
plurality of light beams, so that each of the transformed light
beams is characterized by a second beam divergence that is smaller
than the first beam divergence of the corresponding light beam;
directing the plurality of the transformed light beams onto a
diffractive optical element at different angles of incidence; and
diffracting the transformed light beams by a diffractive optical
element to provide a plurality of light patterns.
157. The method according to claim 156, wherein a combination of
the optical subunit and the diffractive optical element is
characterized by a distortion function, wherein the plurality of
individual emitters is arranged in a non-uniform configuration
whose relation to a predefined uniform grid is an inverse function
of the distortion function.
158. The method according to claim 156, wherein the second beam
divergence is lesser than or equal to a facilitating beam
divergence of the diffractive optical element.
159. The method according to claim 156, wherein said transforming
and said directing comprises using an optical subunit which is an
optical assembly comprising a plurality of optical elements having
a common optical axis.
160. The method according to claim 159, wherein said transforming
comprises using transforming optical components common to the
plurality of light beams.
161. The method according to claim 156, wherein the plurality of
light beams are emitted by an emitter array, and the method further
comprises positioning the emitter array and the optical subunit
relative to one another such that the optical subunit further
transforms the plurality of light beams by deflecting the plurality
of light beams, and the method further comprises projecting the
plurality of transformed light beams onto the diffractive optical
element at different angles of incidence, thereby producing a
plurality of light patterns
162. The method according to claim 161, wherein the plurality of
light patterns are copies of a light pattern.
163. The method according to claim 162, wherein the plurality of
copies of the light pattern are generated using the diffractive
optical element as a single diffractive optical element, thereby
facilitating projection of a high contrast and high clarity overall
output pattern of the optical system.
164. The method according to claim 162, wherein each provided copy
of the light pattern partly overlaps at least one other provided
copy of the light pattern, wherein the light pattern comprises
multiple copies of a repeated subpattern, wherein in each provided
copy of the light pattern at least one subpattern overlaps a
subpattern of at least one other provided copy of the light pattern
generated by light originating from another light emitter.
165. The method according to claim 156, further comprising
controlling activation of different subgroups of emitters of the
emitter array, thereby resulting in providing of offset overall
output patterns of the optical system at different times.
166. The method according to claim 161, wherein the transforming is
accomplished by an optical subunit, wherein the emitting is
accomplished by a plurality of individual emitters which are
positioned at a focal plane of the optical subunit.
167. The method according to claim 156, further comprising:
projecting onto an object at least a part of a structured light
pattern which comprises the plurality of light patterns; and
processing an image of a reflected portion of the projected
structured light pattern to determine range parameters.
168. The method according to claim 156, wherein a width of each one
of the plurality of transformed light beams is greater than a beam
width of a facilitating beam of the diffractive optical
element.
169. The method according to claim 156, wherein a beam width of
each one of the plurality of transformed light beams is greater
than the native beam width of the light beam.
170. The method according to claim 169, wherein a width of each of
the plurality of transformed light beams is greater than the native
beam width by at least a factor 3.
Description
RELATED APPLICATIONS
[0001] The present application claims priority from U.S.
Provisional Patent Application No. 62/036,158.
FIELD
[0002] The invention is related to systems, methods, and computer
program products for structured light projection and imaging.
BACKGROUND
[0003] Sazbon et al. describe a method of this sort for range
estimation in "Qualitative Real-Time Range Extraction for
Preplanned Scene Partitioning Using Laser Beam Coding," Pattern
Recognition Letters 26 (2005), pages 1772-1781, which is
incorporated herein by reference. A phase-only filter codes the
laser beam into M different diffraction patterns, corresponding to
M different range segments in the workspace. Thus, each plane in
the illuminated scene is irradiated with the pattern corresponding
to the range of the plane from the light source. A common camera
can be used to capture images of the scene, which may be processed
to determine the ranges of objects in the scene. The authors
describe an iterative procedure for designing the phase-only filter
based on the Gerchberg-Saxton algorithm.
[0004] US Patent Publication No. 2011/0158508 to Shpunt et al.
discloses a method for mapping which uses a diffractive optical
element and includes projecting onto an object a pattern of
multiple spots having respective positions and shapes, such that
the positions of the spots in the pattern are uncorrelated, while
the shapes share a common characteristic. An image of the spots on
the object is captured and processed so as to derive a
three-dimensional (3D) map of the object.
[0005] U.S. Pat. Nos. 8,090,194, 8,208,719 and 8,538,166 to Gordon
et al. and International Publication No. WO2008062407 also to
Gordon et al. disclose various aspects of structured light
projection and imaging as well features, hardware and algorithms
used in structured light projection and imaging.
GENERAL DESCRIPTION
[0006] In accordance with an aspect of the presently disclosed
subject matter, there is provided an optical system, including: (a)
an emitter array including a plurality of individual emitters,
wherein each emitter in the emitter array is operable to emit a
light beam which is characterized by a native beam width; (b) an
optical subunit, operable to transform a plurality of light beams
emitted by the emitter array, wherein each of the transformed light
beams is characterized by an expanded beam width that is wider than
the native beam width of the corresponding light beam and is wider
than a facilitating beam width; and (c) a diffractive optical
element (DOE) that is capable of diffracting the transformed light
beams to provide light patterns whose angular resolution meets a
light pattern target angular resolution criteria.
[0007] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is an optical assembly including a plurality of
optical elements.
[0008] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
emitter in the emitter array is operable to emit a light beam whose
native beam width is narrower than the facilitating beam width by
at least one order of magnitude.
[0009] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is an optical assembly including a plurality of
optical elements having a common optical axis common to the
plurality of optical elements.
[0010] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is operable to transform the plurality of light
beams to provide the plurality of transformed light beams using
transforming optical components included in the optical subunit,
wherein the transforming optical components are common to the
plurality of light beams.
[0011] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
emitter array and the optical subunit are positioned relative to
one another such that the optical subunit further transforms the
plurality of light beams by deflecting the plurality of light beams
so that the plurality of transformed light beams are projected onto
the diffractive optical element at different angles of incidence,
resulting in providing of a structured light pattern which includes
the plurality of light patterns.
[0012] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
emitter in the emitter array is operable to emit a light beam, out
of the plurality of light beams, which is characterized by a first
beam divergence; wherein the optical subunit is further operable to
transform the plurality of light beams so that each of the
transformed light beams is characterized by a second beam
divergence that is smaller than the first beam divergence of the
corresponding light beam.
[0013] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein for
each individual emitter of the emitter array there is at least one
other individual emitter of the emitter array positioned at a
distance which is at least 10 times smaller than any beam-width of
any transformed light beam out of the plurality of transformed
light beams.
[0014] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
expanded beam widths of each of the plurality of transformed light
beams is at least 3 times larger than the native beam width of the
corresponding light beams.
[0015] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein
[0016] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is a telecentric optical subunit.
[0017] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of individual emitters are positioned on a focal plane of
the optical subunit.
[0018] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light beams propagates to the optical subunit in
substantially parallel paths.
[0019] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a predetermined light pattern.
[0020] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
copies of the predetermined light pattern are adjacent to each
other.
[0021] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
utilization of the single diffractive optical element by the
optical system for the generating of the plurality of copies of the
predetermined light pattern facilitates projection of a high
contrast and high clarity overall output pattern of the optical
system.
[0022] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
provided copy of the predetermined light pattern partly overlaps at
least one other provided copy of the predetermined light
pattern.
[0023] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
predetermined light pattern includes multiple copies of a repeated
subpattern, wherein in each provided copy of the predetermined
light pattern at least one subpattern overlaps a subpattern of at
least one other provided copy of the predetermined light pattern
generated by light originating from another light emitter.
[0024] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including an emitter array control system which is configured and
operable to control activation of different subgroups of emitters
of the emitter array, thereby resulting in providing of offset
overall output patterns of the optical system at different
times.
[0025] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including projection optics to image at least a part of a
structured light pattern which includes the plurality of light
patterns onto an object, an imaging sensor adapted to capture an
image of the object with the structured light pattern projected
thereon, and a processing unit adapted to process the image to
determine range parameters.
[0026] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical elements,
wherein the common optical axis is folded at least once.
[0027] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
emitter of the emitter array is a vertical-cavity surface-emitting
laser (VCSEL) emitter.
[0028] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
emitter array is dense with individual emitters of coherent light
beams, thereby enabling spatially efficient providing of a high
energy structured light pattern.
[0029] In accordance with an aspect of the presently disclosed
subject matter, there is provided an optical system, including: (a)
an emitter array including a plurality of individual emitters,
wherein each emitter in the emitter array is operable to emit a
light beam which is characterized by a first beam divergence; (b)
an optical subunit, operable to transform a plurality of light
beams emitted by the emitter array, wherein each of the transformed
light beams is characterized by a second beam divergence that is
smaller than the first beam divergence of the corresponding light
beam; and (c) a diffractive optical element (DOE) capable of
diffracting the transformed light beams to provide light
patterns.
[0030] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is an optical assembly including a plurality of
optical elements.
[0031] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein a
facilitating beam divergence is defined for the DOE so that
incidence upon the DOE of coherent light beams whose divergence is
lower than the facilitating beam divergence result in provision of
light patterns whose contrast meets a light pattern target contrast
criteria; wherein the second beam divergences of the plurality of
transformed light beams are lower than the facilitating beam
divergence.
[0032] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
emitter in the emitter array is operable to emit a light beam whose
first beam divergence is larger than the facilitating beam
divergence by at least one order of magnitude.
[0033] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is an optical assembly including a plurality of
optical elements having a common optical axis common to the
plurality of optical elements.
[0034] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is operable to transform the plurality of light
beams to provide the plurality of transformed light beams using
transforming optical components included in the optical subunit,
wherein the transforming optical elements are common to the
plurality of light beams.
[0035] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
emitter array and the optical subunit are positioned relative to
one another such that the optical subunit further transform the
plurality of light beams by deflecting the plurality of light beams
so that the plurality of transformed light beams are projected onto
the diffractive optical element at different angles of incidence,
resulting in providing of a plurality of light patterns by the
diffractive optical element.
[0036] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is a telecentric optical subunit.
[0037] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of individual emitters are positioned on a focal plane of
the optical subunit.
[0038] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light beams propagates to the optical subunit in
substantially parallel paths.
[0039] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a predetermined light pattern.
[0040] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
copies of the predetermined light pattern are adjacent to each
other.
[0041] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
utilization of the single diffractive optical element by the
optical system for the generating of the plurality of copies of the
predetermined light pattern facilitates projection of a high
contrast and high clarity overall output pattern of the optical
system.
[0042] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
provided copy of the predetermined light pattern partly overlaps at
least one other provided copy of the predetermined light
pattern.
[0043] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
predetermined light pattern includes multiple copies of a repeated
subpattern, wherein in each provided copy of the predetermined
light pattern at least one subpattern overlaps a subpattern of at
least one other provided copy of the predetermined light pattern
generated by light originating from another light emitter.
[0044] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including an emitter array control system which is configured and
operable to control activation of different subgroups of emitters
of the emitter array, thereby resulting in providing of offset
overall output patterns of the optical system at different
times.
[0045] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including projection optics to image at least a part of a
structured light pattern which includes the plurality of light
patterns onto an object, an imaging sensor adapted to capture an
image of the object with the structured light pattern projected
thereon, and a processing unit adapted to process the image to
determine range parameters.
[0046] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical elements,
wherein the common optical axis is folded at least once.
[0047] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
emitter of the emitter array is a vertical-cavity surface-emitting
laser (VCSEL) emitter.
[0048] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
emitter array is dense with individual emitters of coherent light
beams, thereby enabling spatially efficient providing of a high
energy structured light pattern.
[0049] In accordance with an aspect of the presently disclosed
subject matter, there is provided an optical system, including: (a)
an emitter array including a plurality of individual emitters,
wherein each emitter in the emitter array is operable to emit a
light beam; (b) an optical subunit, operable to: (i) transform a
plurality of light beams emitted by the emitter array, wherein the
transformation includes expansion and/or collimation of the
plurality of light beams; and (ii) to direct the plurality of
transformed light beams onto the diffractive optical element at
different angles of incidence, resulting in providing of a
plurality of light patterns by the diffractive optical element; and
(c) a diffractive optical element (DOE) that is capable of
diffracting the transformed light beams to provide light
patterns.
[0050] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein for
each individual emitter of the emitter array there is at least one
other individual emitter of the emitter array positioned at a
distance which is smaller than any beam width of any transformed
light beam out of the plurality of transformed light beams.
[0051] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is an optical assembly including a plurality of
optical elements.
[0052] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical
elements.
[0053] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is operable to transform the plurality of light
beams to provide the plurality of transformed light beams using
transforming optical components, out of the plurality of optical
components, which are common to the plurality of light beams.
[0054] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
emitter array and the optical subunit are positioned relative to
one another such that the optical subunit further transform the
plurality of light beams by deflecting the plurality of light beams
so that the plurality of transformed light beams are projected onto
the diffractive optical element at different angles of incidence,
resulting in providing of a plurality of light patterns by the
diffractive optical element.
[0055] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is a telecentric optical subunit.
[0056] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of individual emitters are positioned on a focal plane of
the optical subunit.
[0057] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light beams propagates to the optical subunit in
substantially parallel paths.
[0058] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a predetermined light pattern.
[0059] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
copies of the predetermined light pattern are adjacent to each
other.
[0060] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
utilization of the single diffractive optical element by the
optical system for the generating of the plurality of copies of the
predetermined light pattern facilitates projection of a high
contrast and high clarity overall output pattern of the optical
system.
[0061] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
provided copy of the predetermined light pattern partly overlaps at
least one other provided copy of the predetermined light
pattern.
[0062] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
predetermined light pattern includes multiple copies of a repeated
subpattern, wherein in each provided copy of the predetermined
light pattern at least one subpattern overlaps a subpattern of at
least one other provided copy of the predetermined light pattern
generated by light originating from another light emitter.
[0063] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including an emitter array control system which is configured and
operable to control activation of different subgroups of emitters
of the emitter array, thereby resulting in providing of offset
overall output patterns of the optical system at different
times.
[0064] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including projection optics to image at least a part of a
structured light pattern which includes the plurality of light
patterns onto an object, an imaging sensor adapted to capture an
image of the object with the structured light pattern projected
thereon, and a processing unit adapted to process the image to
determine range parameters.
[0065] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical elements,
wherein the common optical axis is folded at least once.
[0066] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
emitter of the emitter array is a vertical-cavity surface-emitting
laser (VCSEL) emitter.
[0067] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
emitter array is dense with individual emitters of coherent light
beams, thereby enabling spatially efficient providing of a high
energy structured light pattern.
[0068] In accordance with an aspect of the presently disclosed
subject matter, there is provided an optical system, including: (a)
an emitter array including a plurality of individual emitters
arranged so as to form a planar emission plane, wherein each
emitter in the emitter array is operable to emit a light beam; (b)
an optical subunit, operable to: (i) transform a plurality of light
beams emitted by the emitter array, wherein the transformation
includes expansion and/or collimation of the plurality of light
beams; and (ii) to direct the plurality of transformed light beams
onto the diffractive optical element at different angles of
incidence, resulting in providing of a plurality of light patterns
by the diffractive optical element; and (c) a diffractive optical
element (DOE) that is capable of diffracting the transformed light
beams to provide light patterns.
[0069] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical
elements.
[0070] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is operable to transform the plurality of light
beams to provide the plurality of transformed light beams using
transforming optical components, out of the plurality of optical
components, which are common to the plurality of light beams.
[0071] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
emitter array and the optical subunit are positioned relative to
one another such that the optical subunit further transform the
plurality of light beams by deflecting the plurality of light beams
so that the plurality of transformed light beams are projected onto
the diffractive optical element at different angles of incidence,
resulting in providing of a plurality of light patterns by the
diffractive optical element.
[0072] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is a telecentric optical subunit.
[0073] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of individual emitters are positioned on a focal plane of
the optical subunit.
[0074] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light beams propagates to the optical subunit in
substantially parallel paths.
[0075] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a predetermined light pattern.
[0076] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
copies of the predetermined light pattern are adjacent to each
other.
[0077] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
utilization of the single diffractive optical element by the
optical system for the generating of the plurality of copies of the
predetermined light pattern facilitates projection of a high
contrast and high clarity overall output pattern of the optical
system.
[0078] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
provided copy of the predetermined light pattern partly overlaps at
least one other provided copy of the predetermined light
pattern.
[0079] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
predetermined light pattern includes multiple copies of a repeated
subpattern, wherein in each provided copy of the predetermined
light pattern at least one subpattern overlaps a subpattern of at
least one other provided copy of the predetermined light pattern
generated by light originating from another light emitter.
[0080] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including an emitter array control system which is configured and
operable to control activation of different subgroups of emitters
of the emitter array, thereby resulting in providing of offset
overall output patterns of the optical system at different
times.
[0081] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including projection optics to image at least a part of a
structured light pattern which includes the plurality of light
patterns onto an object, an imaging sensor adapted to capture an
image of the object with the structured light pattern projected
thereon, and a processing unit adapted to process the image to
determine range parameters.
[0082] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical elements,
wherein the common optical axis is folded at least once.
[0083] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
emitter of the emitter array is a vertical-cavity surface-emitting
laser (VCSEL) emitter.
[0084] In accordance with an aspect of the presently disclosed
subject matter, there is provided an optical system, including: (a)
an emitter array including a plurality of individual emitters,
wherein each emitter in the emitter array is operable to emit a
light beam; (b) an optical subunit, operable to transform a
plurality of light beams emitted by the emitter array, wherein the
transformation includes expansion and/or collimation of the
plurality of light beams; (c) a diffractive optical element (DOE)
that is capable of diffracting the transformed light beams to
provide light patterns; wherein a combination of the optical
subunit and the diffractive optical element is characterized by a
distortion function; wherein the plurality of individual emitters
are arranged in a non-uniform configuration whose relation to a
predefined uniform grid is an inverse function of the distortion
function.
[0085] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is operable to direct the plurality of transformed
light beams onto the diffractive optical element at different
angles of incidence, resulting in providing of a plurality of light
patterns by the diffractive optical element.
[0086] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit is a telecentric optical subunit.
[0087] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of individual emitters are positioned on a focal plane of
the optical subunit.
[0088] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light beams propagates to the optical subunit in
substantially parallel paths.
[0089] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a predetermined light pattern.
[0090] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
copies of the predetermined light pattern are adjacent to each
other.
[0091] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
utilization of the single diffractive optical element by the
optical system for the generating of the plurality of copies of the
predetermined light pattern facilitates projection of a high
contrast and high clarity overall output pattern of the optical
system.
[0092] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
provided copy of the predetermined light pattern partly overlaps at
least one other provided copy of the predetermined light
pattern.
[0093] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
predetermined light pattern includes multiple copies of a repeated
subpattern, wherein in each provided copy of the predetermined
light pattern at least one subpattern overlaps a subpattern of at
least one other provided copy of the predetermined light pattern
generated by light originating from another light emitter.
[0094] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including an emitter array control system which is configured and
operable to control activation of different subgroups of emitters
of the emitter array, thereby resulting in providing of offset
overall output patterns of the optical system at different
times.
[0095] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, further
including projection optics to image at least a part of a
structured light pattern which includes the plurality of light
patterns onto an object, an imaging sensor adapted to capture an
image of the object with the structured light pattern projected
thereon, and a processing unit adapted to process the image to
determine range parameters.
[0096] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical elements,
wherein the common optical axis is folded at least once.
[0097] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a system, wherein each
emitter of the emitter array is a vertical-cavity surface-emitting
laser (VCSEL) emitter.
[0098] In accordance with an aspect of the presently disclosed
subject matter, there is provided a method for projection, the
method including: (a) emitting a plurality of light beams, wherein
each of the plurality of light beams is characterized by a native
beam width; (b) transforming the plurality of light beams so that
each of the transformed light beams is characterized by an expanded
beam width that is wider than the native beam width of the
corresponding light beam and is wider than a facilitating beam
width; and (c) diffracting the transformed light beams by a
diffractive optical element (DOE) to provide light patterns whose
angular resolution meets a light pattern target angular resolution
criteria.
[0099] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
emitting includes emitting the plurality of light beams whose
native beam widths are narrower than the facilitating beam width by
at least one order of magnitude.
[0100] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, further
including deflecting the plurality of light beams, projecting the
plurality of transformed light beams onto the diffractive optical
element at different angles of incidence, and providing a plurality
of light patterns by the diffractive optical element, wherein the
structured light pattern includes the plurality of light
patterns.
[0101] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein each
light beam out of the plurality of light beams is characterized by
a first beam divergence; wherein the transforming of the plurality
of light beams includes transforming the plurality of light beams
so that each of the transformed light beams is characterized by a
second beam divergence that is smaller than the first beam
divergence of the corresponding light beam.
[0102] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
transforming of the plurality of light beams includes transforming
the plurality of light beams so that the expanded beam widths of
each of the plurality of transformed light beams is at least 3
times larger than the native beam width of the corresponding light
beams.
[0103] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
transforming is executed by a telecentric optical subunit.
[0104] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
transforming is executed by an optical subunit, wherein the
emitting is executed by a plurality of individual emitters which
are positioned on a focal plane of the optical subunit.
[0105] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of light beams propagates to the optical subunit in
substantially parallel paths.
[0106] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a predetermined light pattern.
[0107] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
copies of the predetermined light pattern are adjacent to each
other.
[0108] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of copies of the predetermined light pattern facilitates
projection of a high contrast and high clarity overall output
pattern of the optical system.
[0109] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein each
provided copy of the predetermined light pattern partly overlaps at
least one other provided copy of the predetermined light
pattern.
[0110] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
predetermined light pattern includes multiple copies of a repeated
subpattern, wherein in each provided copy of the predetermined
light pattern at least one subpattern overlaps a subpattern of at
least one other provided copy of the predetermined light pattern
generated by light originating from another light emitter.
[0111] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, further
including an emitter array control system which is configured and
operable to control activation of different subgroups of emitters
of the emitter array, thereby resulting in providing of offset
overall output patterns of the optical system at different
times.
[0112] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, further
including projecting onto an object at least a part of a structured
light pattern which includes the plurality of light patterns,
capturing an image of the object with the structured light pattern
projected thereon, and processing the image to determine range
parameters.
[0113] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical elements,
wherein the common optical axis is folded at least once.
[0114] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein each
emitter of the emitter array is a vertical-cavity surface-emitting
laser (VCSEL) emitter.
[0115] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
emitter array is dense with individual emitters of coherent light
beams, thereby enabling spatially efficient providing of a high
energy structured light pattern.
[0116] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
emitter array includes a plurality of individual emitters arranged
so as to form a planar emission plane.
[0117] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein a
combination of the optical subunit and the diffractive optical
element is characterized by a distortion function; wherein the
plurality of individual emitters are arranged in a non-uniform
configuration whose relation to a predefined uniform grid is an
inverse function of the distortion function.
[0118] In accordance with an aspect of the presently disclosed
subject matter, there is provided a method for projection, the
method including: (a) emitting a plurality of light beams, wherein
each of the plurality of light is characterized by a first beam
divergence; (b) transforming the plurality of light beams so that
each of the transformed light beams is characterized by a second
beam divergence that is smaller than the first beam divergence of
the corresponding light beam; and (c) diffracting the transformed
light beams by a diffractive optical element (DOE) to provide light
patterns.
[0119] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
optical subunit is. an optical assembly including a plurality of
optical elements.
[0120] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein a
facilitating beam divergence is defined for the DOE so that
incidence upon the DOE of coherent light beams whose divergence is
lower than the facilitating beam divergence result in provision of
light patterns whose contrast meets a light pattern target contrast
criteria; wherein the second beam divergences of the plurality of
transformed light beams are lower than the facilitating beam
divergence.
[0121] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein each
emitter in the emitter array is operable to emit a light beam whose
first beam divergence is larger than the facilitating beam
divergence by at least one order of magnitude.
[0122] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
optical subunit is an optical assembly including a plurality of
optical elements having a common optical axis common to the
plurality of optical elements.
[0123] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
optical subunit is operable to transform the plurality of light
beams to provide the plurality of transformed light beams using
transforming optical components included in the optical subunit,
wherein the transforming optical elements are common to the
plurality of light beams.
[0124] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
emitter array and the optical subunit are positioned relative to
one another such that the optical subunit further transform the
plurality of light beams by deflecting the plurality of light beams
so that the plurality of transformed light beams are projected onto
the diffractive optical element at different angles of incidence,
resulting in providing of a plurality of light patterns by the
diffractive optical element.
[0125] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
transforming is executed by a telecentric optical subunit.
[0126] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
transforming is executed by an optical subunit, wherein the
emitting is executed by a plurality of individual emitters which
are positioned on a focal plane of the optical subunit.
[0127] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of light beams propagates to the optical subunit in
substantially parallel paths.
[0128] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a predetermined light pattern.
[0129] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
copies of the predetermined light pattern are adjacent to each
other.
[0130] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of copies of the predetermined light pattern facilitates
projection of a high contrast and high clarity overall output
pattern of the optical system.
[0131] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein each
provided copy of the predetermined light pattern partly overlaps at
least one other provided copy of the predetermined light
pattern.
[0132] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
predetermined light pattern includes multiple copies of a repeated
subpattern, wherein in each provided copy of the predetermined
light pattern at least one subpattern overlaps a subpattern of at
least one other provided copy of the predetermined light pattern
generated by light originating from another light emitter.
[0133] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, further
including an emitter array control system which is configured and
operable to control activation of different subgroups of emitters
of the emitter array, thereby resulting in providing of offset
overall output patterns of the optical system at different
times.
[0134] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, further
including projecting onto an object at least a part of a structured
light pattern which includes the plurality of light patterns,
capturing an image of the object with the structured light pattern
projected thereon, and processing the image to determine range
parameters.
[0135] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical elements,
wherein the common optical axis is folded at least once.
[0136] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein each
emitter of the emitter array is a vertical-cavity surface-emitting
laser (VCSEL) emitter.
[0137] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
emitter array is dense with individual emitters of coherent light
beams, thereby enabling spatially efficient providing of a high
energy structured light pattern.
[0138] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
emitter array includes a plurality of individual emitters arranged
so as to form a planar emission plane.
[0139] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein a
combination of the optical subunit and the diffractive optical
element is characterized by a distortion function; wherein the
plurality of individual emitters are arranged in a non-uniform
configuration whose relation to a predefined uniform grid is an
inverse function of the distortion function.
[0140] In accordance with an aspect of the presently disclosed
subject matter, there is provided a method for projection, the
method including: (a) emitting a plurality of light beams; (b)
transforming the plurality of light beams, the transforming
including expanding and/or collimating of the plurality of light
beams; (c) directing the plurality of transformed light beams onto
a diffractive optical element at different angles of incidence; and
(d) diffracting the plurality of transformed light beams by the
diffractive optical element (DOE) to provide a plurality of light
patterns; wherein the emitting includes emitting the plurality of
light beams by a plurality of individual emitters which are
positioned so that for each of the individual emitters there is at
least one other individual emitter positioned at a distance which
is smaller than any beam width of any transformed light beam out of
the plurality of transformed light beams.
[0141] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
transforming is executed by a telecentric optical subunit.
[0142] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
transforming is executed by an optical subunit, wherein the
emitting is executed by a plurality of individual emitters which
are positioned on a focal plane of the optical subunit.
[0143] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of light beams propagates to the optical subunit in
substantially parallel paths.
[0144] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of light patterns provided by the diffractive optical
element are copies of a predetermined light pattern.
[0145] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
copies of the predetermined light pattern are adjacent to each
other.
[0146] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
plurality of copies of the predetermined light facilitates
projection of a high contrast and high clarity overall output
pattern of the optical system.
[0147] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein each
provided copy of the predetermined light pattern partly overlaps at
least one other provided copy of the predetermined light
pattern.
[0148] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
predetermined light pattern includes multiple copies of a repeated
subpattern, wherein in each provided copy of the predetermined
light pattern at least one subpattern overlaps a subpattern of at
least one other provided copy of the predetermined light pattern
generated by light originating from another light emitter.
[0149] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, further
including an emitter array control system which is configured and
operable to control activation of different subgroups of emitters
of the emitter array, thereby resulting in providing of offset
overall output patterns of the optical system at different
times.
[0150] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, further
including projecting onto an object at least a part of a structured
light pattern which includes the plurality of light patterns,
capturing an image of the object with the structured light pattern
projected thereon, and processing the image to determine range
parameters.
[0151] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
optical subunit includes a plurality of optical elements having a
common optical axis common to the plurality of optical elements,
wherein the common optical axis is folded at least once.
[0152] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein each
emitter of the emitter array is a vertical-cavity surface-emitting
laser (VCSEL) emitter.
[0153] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
emitter array is dense with individual emitters of coherent light
beams, thereby enabling spatially efficient providing of a high
energy structured light pattern.
[0154] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
emitter array includes a plurality of individual emitters arranged
so as to form a planar emission plane.
[0155] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein a
combination of the optical subunit and the diffractive optical
element is characterized by a distortion function; wherein the
plurality of individual emitters are arranged in a non-uniform
configuration whose relation to a predefined uniform grid is an
inverse function of the distortion function.
[0156] in accordance with an aspect of the presently disclosed
subject matter, there is provided a method, including : (a)
obtaining optical characteristics of a doe positioned at a given
distance from a light source; (b) obtaining data in respect of a
provisional light beams emission layout through the doe; (c)
obtaining a target emission layout; and (d) determining an emitters
layout based on the target emission layout and based on the
provisional light beams emission layout.
[0157] In accordance with an embodiment of the presently disclosed
subject matter, there is further provided a method, wherein the
determining comprises determining an emitters layout, such that
light emitted by a light source positioned at the given distance
from the DOE and having a plurality of emitters arranged according
to the emitters layout is diffracted through the DOE is
characterized by a layout that meets a target emission criterion
that is based on the target emission layout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0158] In order to understand the invention and to see how it may
be carried out in practice, embodiments will now be described, by
way of non-limiting example only, with reference to the
accompanying drawings, in which:
[0159] FIGS. 1, 2, 3A and 3B are functional block diagrams
illustrating various examples of optical system, in accordance with
examples of the presently disclosed subject matter;
[0160] FIGS. 4A and 4B illustrate examples of an optical system
within an environment which includes the optical system and a
projection of structured light, in accordance with examples of the
presently disclosed subject matter;
[0161] FIG. 4C is an exploded view of an example of the projection
of an optical system, including projection of structured light made
of a plurality of partially overlapping light patterns, in
accordance with examples of the presently disclosed subject
matter;
[0162] FIGS. 5 and 6 are functional block diagrams illustrating
various examples of optical system, in accordance with examples of
the presently disclosed subject matter;
[0163] FIG. 7 illustrates an example of an optical system within an
environment which includes the optical system and an object, in
accordance with examples of the presently disclosed subject
matter;
[0164] FIGS. 8, 9 and 10 are functional block diagrams illustrating
various examples of optical system, in accordance with examples of
the presently disclosed subject matter;
[0165] FIG. 11 illustrates a hexagonal configuration of emitter
array in accordance with examples of the presently disclosed
subject matter;
[0166] FIGS. 12A through 12G includes diagrams which are related to
possible distortions in the light patterns generated by the system
of FIG. 1, and ways to reduce such distortion, in accordance with
examples of the presently disclosed subject matter;
[0167] FIGS. 13, 14 and 15 is a functional block diagram
illustrating an example of an optical system, in accordance with
examples of the presently disclosed subject matter;
[0168] FIG. 16 is a block diagram illustration of a system
according to examples of the presently disclosed subject matter,
including support for a remote mode of a 3D capture application
feature;
[0169] FIGS. 17-24 are flow charts illustrating examples of various
methods for projection, in accordance with examples of the
presently disclosed subject matter; and
[0170] FIG. 25 is a flow chart illustrating an example of a method,
in accordance with examples of the presently disclosed subject
matter.
[0171] It will be appreciated that for simplicity and clarity of
illustration, elements shown in the figures have not necessarily
been drawn to scale. For example, the dimensions of some of the
elements may be exaggerated relative to other elements for clarity.
Further, where considered appropriate, reference numerals may be
repeated among the figures to indicate corresponding or analogous
elements.
DETAILED DESCRIPTION
[0172] In the following detailed description, numerous specific
details are set forth in order to provide a thorough understanding
of the invention. However, it will be understood by those skilled
in the art that the present invention may be practiced without
these specific details. In other instances, well-known methods,
procedures, and components have not been described in detail so as
not to obscure the present invention.
[0173] In the drawings and descriptions set forth, identical
reference numerals indicate those components that are common to
different embodiments or configurations.
[0174] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. The
materials, methods, and examples provided herein are illustrative
only and not intended to be limiting. Except to the extent
necessary or inherent in the processes themselves, no particular
order to steps or stages of methods and processes described in this
disclosure, including the figures, is intended or implied. In many
cases the order of process steps may vary without changing the
purpose or effect of the methods described.
[0175] Unless specifically stated otherwise, as apparent from the
following discussions, it is appreciated that throughout the
specification discussions utilizing terms such as "processing",
"computing", "determining", "generating", "configuring",
"selecting", "defining", or the like, include action and/or
processes of a computer that manipulates and/or transforms data
into other data, said data represented as physical quantities, e.g.
such as electronic quantities, and/or said data representing the
physical objects. The terms "computer", "processor", and
"controller" should be expansively construed to cover any kind of
electronic device, component or unit with data processing
capabilities, including, by way of non-limiting example, a personal
computer, a server, a computing system, a communication device, a
processor (e.g. digital signal processor (DSP), and possibly with
embedded memory), a microcontroller, a field programmable gate
array (FPGA), an application specific integrated circuit (ASIC),
etc.), any other electronic computing device, and or any
combination thereof.
[0176] The operations in accordance with the teachings herein may
be performed by a computer specially constructed for the desired
purposes or by a general purpose computer specially configured for
the desired purpose by a computer program stored in a computer
readable storage medium.
[0177] As used herein, the phrase "for example," "such as", "for
instance" and variants thereof describe non-limiting embodiments of
the presently disclosed subject matter. Reference in the
specification to "one case", "some cases", "other cases" or
variants thereof means that a particular feature, structure or
characteristic described in connection with the embodiment(s) is
included in at least one embodiment of the presently disclosed
subject matter. Thus the appearance of the phrase "one case", "some
cases", "other cases" or variants thereof does not necessarily
refer to the same embodiment(s).
[0178] It is appreciated that certain features of the presently
disclosed subject matter, which are, for clarity, described in the
context of separate embodiments, may also be provided in
combination in a single embodiment. Conversely, various features of
the presently disclosed subject matter, which are, for brevity,
described in the context of a single embodiment, may also be
provided separately or in any suitable sub-combination.
[0179] In embodiments of the presently disclosed subject matter one
or more stages illustrated in the figures may be executed in a
different order and/or one or more groups of stages may be executed
simultaneously and vice versa. The figures illustrate a general
schematic of the system architecture in accordance with an
embodiment of the presently disclosed subject matter. Each module
in the figures can be made up of any combination of software,
hardware and/or firmware that performs the functions as defined and
explained herein. The modules in the figures may be centralized in
one location or dispersed over more than one location.
[0180] It should be noted that some examples of the presently
disclosed subject matter are not limited in application to the
details of construction and the arrangement of the components set
forth in the following description or illustrated in the drawings.
The invention can be capable of other embodiments or of being
practiced or carried out in various ways. Also, it is to be
understood that the phraseology and terminology employed herein is
for the purpose of description and should not be regarded as
limiting.
[0181] In this document, an element of a drawing that is not
described within the scope of the drawing and is labeled with a
numeral that has been described in a previous drawing has the same
use and description as in the previous drawings. Similarly, an
element that is identified in the text by a numeral that does not
appear in the drawing described by the text, has the same use and
description as in the previous drawings where it was described.
[0182] The drawings in this document may not be to any scale.
Different Figs. may use different scales and different scales can
be used even within the same drawing, for example different scales
for different views of the same object or different scales for the
two adjacent objects.
[0183] FIG. 1 is a functional block diagram illustrating an example
of optical system 200, in accordance with examples of the presently
disclosed subject matter. Optical system 200 can include emitter
array 210 as a light source whose light can be diffracted by
diffractive optical element 230, after being manipulated by optical
subunit 220. Along this optical path, the light emitted by emitter
array 210 is patterned to provide structured light 300 having a
corresponding structured light pattern.
[0184] While not necessarily coded, the structured light pattern
may be a coded light pattern. The term "coded light pattern" (also
occasionally referred to as "structured light pattern" and "coded
structured light pattern") is well accepted in the art, and should
be construed in a non-limiting way to include patterns which are
specially designed so that codewords are assigned to a set of
locations (e.g. pixels or pixel neighborhoods) of the pattern.
Every coded location (e.g. every coded pixel or coded pixel
neighborhoods) has its own codeword, so there is a direct mapping
from the codewords to the corresponding coordinates of the location
(e.g. pixel or pixel neighborhood) in the pattern. The codewords
are symbols (e.g. alphabetic characters such as numbers) which are
embedded in the coded pattern, e.g. using any combination of one or
more of the following: grey levels, colors, color levels,
polarization and geometrical shapes. Examples of coded light
pattern are disclosed in various patents and patent applications
assigned to the assignee of the present application, such as U.S.
Pat. Nos. 8,090,194, 8,538,166, 8,208,719, and International
Publication No. WO2008/062407, all of which are hereby incorporated
by reference in their entirety.
[0185] Emitter array 210 includes a plurality of individual
emitters 212, and each emitter 212 in the emitter array 210 is
operable to emit a light beam 110. Optical subunit 220 is operable
to transform a plurality of light beams 110 emitted by emitter
array 210; and diffractive optical element (DOE) 230 is capable of
diffracting the transformed light beams 130 so as to provide light
patterns.
[0186] Diffractive optical element (DOE) 230 is capable of
diffracting an incident coherent to provide a light pattern. The
term "diffractive optical element" (commonly abbreviated to DOE) is
well accepted in the art, and should be construed in a non-limiting
way to include phase elements that are capable of creating
interference and diffraction to produce arbitrary distributions of
light (usually predefined ones). Diffractive optical element 230
may include a thin micro structure pattern to alter the phase of
the light propagated through it. This phase pattern, based on its
predesign, can be capable of manipulating the light to almost any
desired intensity profile of structured light 300.
[0187] Emitter array 210, which includes a plurality of individual
emitters 212, is operable to emit a plurality of coherent light
beams. Each emitter 212 in the emitter array is operable to emit a
light beam, out of the aforementioned plurality of light beams. It
is noted that while each of the emitted light beams is coherent
within itself, the individual emitters may be implemented such that
there is no coherence between the individual emitters. The
individual emitters 212 of emitter array 210 may be laser emitters.
Especially, each emitter 212 of emitter array 210 may be a
vertical-cavity surface-emitting laser (VCSEL) emitter.
[0188] Optionally, each emitter 212 of the emitter array 210 is a
vertical-cavity surface-emitting laser (VCSEL) emitter, each of
which forms its own coherent light beam. Optionally, emitter array
210 is dense with individual emitters of coherent light beams,
thereby enabling spatially efficient providing of a high energy
structured light pattern.
[0189] It is noted that the number of emitters 212 in emitter array
210 may be selected according to different considerations such as
(though not limited to): required light intensity of system 200,
geometrical considerations, design of the structured light pattern
to be projected by system 200, physical consideration (such as heat
dissipation), and so on. In but few examples, emitter array 210 may
be a 3.times.3 emitters array (i.e. including nine individual
emitters 212 arrange in three rows of emitters, each include three
individual emitters 212), a 10.times.20 emitters array, a
30.times.50 emitters array, a 100.times.100 emitters array, and so
on. It is further noted that the design of the array is not
necessarily a squared tiled or even rectangular tiled (i.e.
emitters are arranged in rows and columns), and many other designs
may be used for the arrangement of emitters 212 within the array.
This may include, by way of example, hexagonal tiling, semi-regular
tiling, and even irregular tiling.
[0190] The light from the various individual emitters 212 of
emitter array 210 is provided to optical subunit 220, which is
operable to transform the plurality of light beams to provide a
plurality of transformed light beams, and to direct the plurality
of transformed light beams onto diffractive optical element 230.
For the readability of the drawings, the light beams as emitted by
emitter array 210 are denoted as light beams 110, and the
transformed light beam directed by optical subunit 220 onto DOE 230
are denoted 130. Within optical subunit, the light beams are
referred to as manipulated light beams 120. It will nevertheless be
clear to a person who is of ordinary skill in the art that the
different numerals are used for illustrative purposes and that the
different light beams numerals refer to the various stages that the
beams of light go through within the system 200.
[0191] Optionally, system 200 may include output optics 240 through
which the transformed light passes before exiting system 200 and
being projected outside (e.g. onto a scene including one or more
objects). Output optics may simply transfer the light as is (e.g. a
protective window), but may possibly also further manipulate it
(e.g. filter it, or direct it towards an object).
[0192] Optical subunit 220 may transform the light from emitter
array 210 in many ways, in order for system 200 to yield the
structured light pattern efficiently (i.e. transducing high
percentage of the energy consumed by the emitter array to the
projected structured light pattern) and with high quality. For
example, structured light pattern efficiency can be defined by a
certain (e.g. predefined) efficiency threshold, such as a certain
percentage (say 80% or above) transducing of the energy consumed by
the emitter array to the projected structured light pattern for a
given quality threshold, for example, measured as a function of
image resolution and/or a level of noise in the projected pattern.
Some of the ways in which the light beams 100 are transformed in
the optical subunit 220 are discussed below, with respect to the
following figures. It is noted that while optical subunit 220 may
include only a single element (e.g. a simple lens), in some cases
it would include more than one element (e.g. a series of lenses),
and therefore the optical subunit 220 is also occasionally referred
to herein as optical assembly 220. In the example of FIG. 1, the
path of the light beams within optical subunit 220 is an arbitrary
illustrative example, and it is noted that different kinds of paths
may be used (e.g. folded paths, etc.).
[0193] It is noted that system 200 may be a telecentric system.
Optionally, optical subunit 220 may be a telecentric optical
subunit, consisting of (or otherwise including) a telecentric
compound lens (as is demonstrated for example in FIG. 2). In
addition to the compound lens, the telecentric optical subunit (if
implemented) may include additional optical components, e.g.
mirrors for folding the optical path of the light beams in optical
subunit 220. This may be achieved by placing the emitting ends of
individual emitters 212 at the focal plane of the telecentric
optical subunit (and especially in the focal plane of the
telecentric compound lens of optical subunit 220, if so
implemented. This is demonstrated by way of example in FIG. 2.
Optionally, the plurality of individual emitters 212 are positioned
on the back focal plane of the optical subunit. While not
necessarily so, the compound lens which may be included in optical
subunit 220 as described throughout the present disclosure may be
implemented as a compound lens which is commonly referred to as a
collimator.
[0194] It is noted that optical unit 220 (whether including a
compound lens or not) may be designed to produce a desired field of
view. It may also be corrected for aberrations and distortion.
[0195] As mentioned above, a single DOE element (DOE 230) is used
for diffracting a plurality of light beams arriving from different
emitters, after these light beams were transformed by optical
subunit 220. In optical subunit 220 itself, the same components may
be used in order to transform the plurality of light beams 110.
That is, optionally, optical subunit 220 may be operable to
transform the plurality of light beams 110 to provide the plurality
of transformed light beams 130 using transforming optical
components (e.g. lenses, mirrors, etc.) included in optical subunit
220, and these transforming optical components may be common to the
plurality of light beams. It is noted that not necessarily all of
the components of optical subunit 220 are used to transform every
single one of light beams 110, and likewise not every light beam
110 must pass through (or be reflected from) all of the optical
components of optical subunit 220.
[0196] Notably, the dimensions of system 200 may vary between
different implementations of the system. For example, different
dimensions of the system 200 can be selected according to a
utilization for which the system is designated (e.g. overall
required illumination pattern size, complexity and intensity, and
so on). However, by way of a non-limiting example only, few
possible dimensions will be stated.
[0197] For example, the distance between emitter array 210 and DOE
230 (denoted L1) may be in the scale of order of a centimeter (e.g.
5 to 50 millimeters). For example, the diameter of optical subunit
220 (and especially of a compound lens included in optical subunit
220), denoted D1, may be also in the same order of magnitude of
about a centimeter (e.g. 1 to 20 millimeters). The focal length of
a compound lens of optical subunit 220 may be in the same order of
magnitude of about a centimeter (e.g. 1 to 20 millimeters). The
diameter of each single emitter 212 in emitter array 210 may be in
the scale of order of a millimeter (e.g. 0.005-1 millimeter). The
field of view (FOV) to which system 200 projects structured light
may vary greatly, e.g. between 15.degree. -150.degree..
[0198] The FOV for system 200 may be designed based on various
parameters, e.g. depending on the required application. For
example, using system 200 for determining range parameters for
automotive applications ((e.g. generating 3D image of object in
front of the car) may require a large FOV (e.g. 90.degree.), while
medical applications may require a smaller FOV (e.g. 45.degree.).
Implementations which rely on dense epipolar separation may require
the projected light pattern to have relatively low radial
distortion, which dictates a relatively low FOV.
[0199] As also demonstrated in FIG. 2, optionally, emitter array
210 and optical subunit 220 are positioned relative to one another
such that optical subunit 220 transforms the plurality of light
beams 110 by deflecting the plurality of light beams 110, so that
the plurality of transformed light beams 130 are projected onto
diffractive optical element 230 at different angles of incidence.
According to examples of the presently disclosed subject matter,
transforming the light beams 130 such that they are projected onto
diffractive optical element 230 at different angles of incidence
can enable provisioning of a plurality of light patterns by the
diffractive optical element 230. Each such light pattern can be a
result of one or more transformed light beams striking the DOE 230
at a different angle than the transformed light beams which result
in other light patterns.
[0200] If the transformed light beams 130 are projected onto DOE
230 at different angles, the structured light pattern projected by
system 200 may include the aforementioned plurality of light
patterns, as discussed in the previous paragraph. It is noted that
the deflection of the plurality of light beams 110 by optical
subunit 220 may include refracting these light beams once or more,
reflecting these light beams once or more, or any other way of
deflecting light beams. It is noted that while not necessarily so,
each of the transformed light beams 130 which are deflected by
optical subunit 220 may be projected onto DOE 230 at totally
different angles (i.e. the incidence angle of the chief ray in each
of these transformed light beams 130 would be singular, shared by
no other chief ray of another transformed light beam 130).
[0201] FIGS. 3A and 3B are functional block diagrams illustrating
an example of optical system 200, in accordance with examples of
the presently disclosed subject matter.
[0202] In FIG. 3A, light rays of a single light beam 110(1) are
traced, from emitter 212(1) of emitter array 210, through optical
subunit 220 where it is deflected as manipulated light beam 120(1),
to its projection onto DOE 230 as transformed light beam 130(1) at
incidence angle .alpha., where it is diffracted by diffractive
optical element 230 to provide light pattern 140(1).
[0203] In FIG. 3B, light rays of two light beams are traced. In
addition to light rays of light beam 110(1) discussed above, light
rays of an additional light beam, light beam 110(2) are also
traced. These light rays of light beam 110(2) are traced from
emitter 212(2) of emitter array 210, through optical subunit 220
where it is deflected as manipulated light beam 120(2), to its
projection onto DOE 230 as transformed light beam 130(2) at
incidence angle .beta.--which is different than the aforementioned
angle .alpha.--where it is diffracted by the same diffractive
optical element, DOE 230, to provide another light pattern 140(2).
Clearly, the light rays emitted by other emitters 212 of emitter
array 210 may strike onto DOE 230 at yet different angles (other
than .alpha. and .beta.), and are not illustrated in order to
simplify the diagram.
[0204] As is demonstrated by way of example in FIG. 3B, the
plurality of light beams 110 emitted by emitter array 210 may
propagate to the optical subunit 220 in parallel (or substantially
parallel) paths. Optionally, all of the light beams 110 may
propagate to the optical subunit 220 parallel to a common optical
axis 10. It is noted that light beams are parallel to each other
even if not all of the rays of one of these light beams are exactly
parallel to all of the rays of any other of the light beams--as can
be seen, this may be difficult if not impossible due to native
divergence of the light source. Light beams are considered parallel
to each other if the chief rays of these light beams are parallel
to each other. It is noted that the light beams emitted by the
individual emitters do not have to be parallel to each other. This
may be achieved, for example, by a proper design of a VCSEL array
source, or a single field lens placed over the array.
[0205] FIG. 4A illustrates an example of system 200 within an
environment which includes system 200 and a projection of
structured light (denoted 150), in accordance with examples of the
presently disclosed subject matter. In the illustrated example of
FIG. 4A, the light beam emitted by each individual emitter of the
3.times.2 emitter array of system 200 (not illustrated) results in
projection of a single light pattern 140, to a total of six such
light patterns. Each of the six light patterns is a square
bull's-eye pattern (including a black square within a black square
frame), and for the sake of illustration, the central top light
pattern in the diagram is highlighted.
[0206] As can be seen, each of the light patterns 140 is emitted
from system 200 in a different angle, and together the light
patterns give rise to a structured light pattern projected by
system 200, which is a structured light pattern consisting of six
square bull's eye targets. Clearly, the shape of each individual
pattern in the example of FIG. 4A is arbitrary, and various
different light patterns may be designed, based on a desired
structured light pattern to be projected by system 200. It is noted
that in the illustrated example, the light patterns 140 resulting
from the different emitters are contiguous with each other
precisely, but this is not necessary, and different light patterns
140 may be designed to partly overlap each other, or be separated
from one another and with various gaps in between the patterns.
[0207] Since the same DOE 230 is used for the diffraction of the
entire plurality of transformed light beams, optionally the
plurality of light patterns 140 provided by the diffractive optical
element 230 are copies of a predetermined light pattern (such as
the repeated square bull's eye pattern in the example of FIG. 4A).
It is noted that the copies may be identical copies of each other
(similar in pattern and in shape), but may also be spatially
distorted copies of the predetermined light pattern. For example,
light patterns 140 projected towards the margins of the structured
light pattern 150 may be elongated with respect to light patterns
140 projected in the center of structured light pattern 150. This
possible elongation may be due to any flat plane on which the
structured light may be projected (and especially one which is
perpendicular to the optical axis) forming different angles with
the chief ray of each projected light pattern 140. Some kinds of
distortion which may occur between the centers of different light
patterns 140 are distortions types known in the art as "Barrel
distortion" (in which image magnification decreases with distance
from the optical axis), "Pincushion distortion" (in which image
magnification increases with the distance from the optical axis)
and "mustache distortion" (which behaves as barrel distortion close
to the image center, and gradually turns into pincushion distortion
towards the image periphery) or distortions similar thereto.
Intensity distortions between the center and the sides of the
structured light pattern may also potentially occur in some
situations. Some ways in which distortion may be reduced in system
200 are discussed with respect to FIGS. 12A through 12G.
[0208] However, in all of these examples, the basic shape of the
predetermined light pattern will be kept in all of its copies (e.g.
the bull's eye pattern) and for this particular example the shape
of the bull's eye pattern will change from being square to a
parallelogram. This can be designed to still be recognizable by an
interpreter of the structured light pattern (e.g. processing unit
260 discussed below). Like the arrangement of emitters 212 in
emitters array 210, the tiling between the copies of the
predetermined light pattern (if implemented) is not necessarily a
squared tiled or even rectangular tiled (i.e. light pattern copies
are arranged in rows and columns), and many other types and shapes
of tiling may be used such as, by way of example, hexagonal tiling,
semi-regular tiling, and even irregular tiling (i.e. tiling without
a repeated pattern).
[0209] As mentioned above, optionally the copies of the
predetermined light pattern (if implemented) are adjacent to each
other (e.g. each copy of the predetermined light pattern may
optionally be adjacent to one, or two, or three, etc. other copies
of the predetermined light pattern). This may be used for tiling an
area whose size is much larger (e.g. at least 50 times larger) than
a size of any of the projected copies of the predetermined light
pattern. This way, using a relatively simple diffractive optical
element as DOE 230 (which is cheaper to design and to manufacture)
which is designed to diffract an incident coherent light beam to
provide a relatively simple light pattern--to generate much larger
and more complex or intricate structured light pattern, e.g. as
demonstrated (in small scale, only 6 times larger) in FIG. 4A.
[0210] Even more so, in the example of system 200 proposed above, a
single diffractive optical element (DOE 230) is used for generating
the plurality of copies of the predetermined light pattern, thereby
facilitating projection of a high contrast and high clarity overall
output pattern of the optical system. In other words, the
configuration of system 200 (e.g. utilization of a single
diffractive optical element the generating of the plurality of
copies of the predetermined light pattern) facilitates projection
of a high contrast and high clarity overall output pattern of the
optical system.
[0211] FIG. 4B illustrates an example of system 200 within an
environment which includes system 200 and a projection of
structured light (denoted 150), in accordance with examples of the
presently disclosed subject matter. In the illustrated example of
FIG. 4B, the light beam emitted by each individual emitter of the
emitter array of system 200 (not illustrated, including five
emitters) results in projection of a single light pattern 140, to a
total of five such light patterns. Like in FIG. 4A, each of the
five light patterns is a square bull's-eye pattern (including a
black square within a black square frame). The edges of each of the
patterns 140 are marked by a dashed line. As can be seen, each of
the patterns 140 partly overlaps at least one other pattern
140.
[0212] Optionally, system 200 may be designed so that each provided
copy of the predetermined light pattern partly overlaps at least
one other provided copy of the predetermined light pattern. The
percent of the overlap between two patterns may vary, but it may
very well exceed 25% (and possibly significantly more). Overlapping
between such patterns may be used for reducing speckle noise, as
discussed, for example, with respect to FIG. 4C.
[0213] FIG. 4C is an exploded view of an example of the projection
of system 200 (not shown), including projection of structured light
denoted 150 made of a plurality of partially overlapping light
patterns 140, in accordance with examples of the presently
disclosed subject matter. In the illustrated example of FIG. 4C,
the light beam emitted by each individual emitter of the emitter
array of system 200 (not illustrated, including three emitters)
results in projection of a single light pattern 140(1), to a total
of three such light patterns. In the case of FIG. 4C, each of the
three light patterns 140(1) includes four square bull's-eye
patterns.
[0214] As is demonstrated in the example of FIG. 4C, optionally,
the predetermined light pattern (of which the light patterns 140(1)
are copies) including multiple copies of a repeated subpattern (in
this case--four copies of a repeated bull's eye pattern), wherein
in each provided copy 140(1) of the predetermined light pattern, at
least one subpattern (i.e. bull's eye pattern in the example)
overlaps a subpattern of at least one other provided copy 140(1) of
the predetermined light pattern which is generated by light
originating from another light emitter. For example, the
highlighted subpattern in structured light pattern 150 (denoted
140') is illuminated by subpatterns included in all of the three
light patterns 140(11), 140(12) and 140(13) of FIG. 4C (the
respective subpatterns are highlighted).
[0215] Therefore, the overall intensity in which this subpattern is
illuminated arrives from three different individual emitters 212.
Optionally, the individual emitters 212 of emitter array 210 are
uncorrelated to each other at least in some respects, meaning that
while possibly emitting in similar emission spectrum/wavelength,
the phases of the different individual emitter are independent of
each other. It is noted that such relation of uncorrelation may
exist between any pair of emitters 212 in emitter array 210, and
may also be limited (if implemented) to subgroups of emitters 212
within emitter array 210. Therefore, the overall intensity in which
a subpattern is illuminated may arrive from a plurality of
different individual emitters 212 whose phase is independent of
each other. Since the illumination arrives from different sources
whose phase is independent of each other, the speckle noise may be
reduced in comparison to the speckle noise that would have been
present in case the same subpattern had been illuminated with the
same intensity by a single coherent source (such as a laser
emitter).
[0216] The degree of overlapping between light patterns may be
predesigned according to various criteria. Such criteria may be,
for example, the amount of speckle noise desired to be reduced (the
more overlapping the better), and on the other had the allowed
minimal distance between the emitters (permitted by considerations
such as heat dissipation and/or coherency independency).
[0217] FIG. 5 is a functional block diagram illustrating an example
of optical system 200, in accordance with examples of the presently
disclosed subject matter. In FIG. 5 there is presented a possible
utilization of the projection of the structured light pattern 150
in system 200. It is noted that these possible uses are offered by
way of a non-limiting example, as many other uses will present
themselves to a person who is of skill in the art. Furthermore,
while the functionalities of utilizing the projection of system 200
are discussed as being implemented by components of the same system
200, it will be clear that such functionalities may also be
implemented by an external system and with additional, fewer or
other components for utilizing the projection.
[0218] As exemplified in FIG. 4B, while not necessarily so system
200 may include projection optics (such as output optics 240)
operable to image at least a part of the structured light pattern
onto an object 400. System 200 may further include one or more
imaging sensors 250 which are adapted to capture an image of object
400 with the structured light pattern 150 projected thereon. It is
noted that the captured image may include only the light of
structured light pattern 150 reflected from object 400 (denoted
310, e.g. if using illumination spectrum not found in the ambient
lighting of object 150), but may also image additional light on top
of the patterned light (such as ambient light reflecting from
object 400, or light emitted by object 400). For example, the image
of the object 400 can be an IR image.
[0219] System 200 in such an implementation may further include
processing unit 260 which is adapted to process the image (or a
plurality of images, e.g. video; possibly with the addition of
other data used in the processing) in order to determine parameters
for object 400. Especially, processing unit 260 may be configured
and operable to process image data generated by the one or more
imaging sensors 250 for determining range parameters for object
400, such as a depth values (e.g. distance from the camera 250) for
different parts of the imaged object 400.
[0220] Different techniques may be used for analyzing patterned
image of an object in order to determine range parameters for the
objects. Several such techniques are discussed in U.S. Pat. Nos.
8,090,194, 8,208,719, 8,538,166, and International Publication No.
WO2008/062407 assigned to the same assignee, all of which are
incorporated herein by reference in their entirety.
[0221] Optionally, processing unit 260 may be configured and
operable to provide to an external system information which is
based on the range parameters determined by it (including the range
parameters themselves and/or information which is selected and/or
generated based on the range parameters). This may be facilitated
by an optional hardware and/or software interface 270 which is
illustrated in FIG. 5.
[0222] FIG. 6 is a functional block diagram illustrating an example
of optical system 200, in accordance with examples of the presently
disclosed subject matter. As discussed above, optionally the
optical subunit 220 may include a plurality of optical elements
having a common optical axis common to the plurality of optical
elements (denoted optical axis 10 in FIGS. 3A and 3B). As
demonstrated in FIG. 6, optionally the common optical axis 10 is
folded at least once.
[0223] It is noted that optionally (e.g. as demonstrated in FIG.
6), the transformed light beams 130 which reach the DOE 230 may at
least partially overlap with each other (i.e., with one or two or
three, etc. other light beams) at the DOE plane.
[0224] FIG. 7 illustrates an example of optical system 200 within
an environment which includes system 200 and an object 400' in
accordance with examples of the presently disclosed subject matter.
For example, object 400' may be an object for which various
parameters--e.g. range parameters--are to be determined by system
200.
[0225] As aforementioned, system 200 may be designed so that light
beams which are emitted from different emitters 212 of the emitter
array 210 result in projection of light pattern in different
angles. As demonstrated in FIG. 3B, optionally the angle in which
such light pattern resulting from a single emitter 212 is
projected--depends on the position of this emitter 212 with respect
to optical subunit 220. Such a configuration enables system 200 to
project two or more different projections of the structured light
pattern, which are shifted with respect to one another. Especially,
such a configuration enables system 200 to project two different
projections of the structured light pattern, which are rigidly
translated with respect to one another.
[0226] In the example illustrated in FIG. 7, system 200 includes an
emitter array control system (not illustrated) which is configured
and operable to control activation of different subgroups of
emitters 212 of emitter array 210, thereby resulting in providing
of offset overall output patterns of the optical system at
different times.
[0227] For example, the individual emitters 212 of emitter array
210 may be arranged in alternating rows (each subgroup including
either odd or even rows) of a hexagonally tiled emitter array 210.
In hexagonal tiling, each row is shifted with respect to the rows
above and below it, and therefore for each emitter 212 in a given
row, the adjacent emitters 212 in the adjacent rows of emitters are
located diagonally with respect thereto. FIG. 11 illustrates a
hexagonal configuration of emitter array in accordance with
examples of the presently disclosed subject matter.
[0228] The result of such a configuration are exemplified in FIG.
7. such an alternating activation of different subgroups of
emitters 212 may enable system 200 to project onto an object 400'
(and onto a background scene which includes in this example a wall
denoted 499) a first projection of the structured light pattern
(denoted "First projection 11" in diagram 7.1 of FIG. 7) and a
second projection of the structured light pattern (denoted "Second
projection 22" in diagram 7.2 of FIG. 7). The light pattern created
by the light of each light beam 110 is denoted light pattern 140 in
the two diagrams of FIG. 7.
[0229] First projection 11 and second projection 22 of the
structured light pattern 150 may be projected onto the scene in
different times (for example, diagram 3A illustrates the
environment in time T1, and diagram 3B illustrates the environment
in time T2 which is later than T1). First projection 11 and second
projection 22 of the structured light pattern 150 may be projected
onto the scene at least partly concurrently, e.g. in a
configuration in which the emitters 212 of different subgroups
emits light in different wavelengths.
[0230] As can be seen, the first projection 11 and the second
projection 22 of the structured light pattern (which in this case
is a coded light pattern which includes alternating zoomorphic
graphemes) are rigidly shifted with respect to one another. As is
also demonstrated in FIG. 7, the structured light pattern may
appear on different scale, depending on the distance of a lighted
object from system 200, and one object may cast a shadow on another
object, thereby hiding a part (or the entirety) of another object
from system 200 from a given perspective.
[0231] In the following figures, examples of variations of some of
the ways in which optical subunit 220 may transform the light of
emitter array 210, and some of the benefits of such configurations,
are discussed in greater detail.
[0232] FIG. 8 is a functional block diagram illustrating an example
of optical system 201 in accordance with examples of the presently
disclosed subject matter. It is noted that system 201 may be
implemented with any of the variations of system 200 discussed
above. It is however noted that system 201 may incorporate any of
the features, components and abilities discussed above with respect
to system 200 as general. Furthermore, system 201 may incorporate
any of the features, components and abilities discussed below with
respect to systems 202, 203, 204 and 205. The components of system
201 are denoted using the same numeral reference used for the
components of system 200, and the variations discussed with respect
to these components in other parts of the document may also
pertain, mutatis mutandis, to system 201.
[0233] In system 201, emitter array 210 includes a plurality of
individual emitters 212. Each emitter 212 in the emitter array 210
of system 201 is operable to emit a light beam 110 which is
characterized by a native beam width 10. Optical subunit 220 of
system 201 is operable to transform a plurality of light beams 110
emitted by the emitter array 210, wherein each of the transformed
light beams 130 is characterized by an expanded beam width 30 that
is wider than the native beam width 10 of the corresponding light
beam 110, and which is wider than a facilitating beam width. DOE
230 in system 201 is capable of diffracting the transformed light
beams so as to provide light patterns whose angular resolution
meets a light pattern target angular resolution criteria.
[0234] System 201 is an optical system which includes a diffractive
optical element (DOE 230), capable of diffracting an incident
coherent light beam to provide a light pattern. It is noted that
while not necessarily so, the resolution of the light pattern
provided by the DOE 230 has a positive correlation with a width of
the incident light beam. That is, the wider the incident light
beam, the finer resolution that the DOE would be able to
produce.
[0235] A facilitating beam width is hereby defined for DOE 230, so
that incidence upon DOE 230 of coherent light beams that are wider
than the facilitating beam width would result in provision of light
patterns whose angular resolution meets a light pattern target
angular resolution criteria.
[0236] For example, for many practical DOE's the beam width should
cover at least 4 periods of the grating structure. So, for example,
if we require an inter beam resolution of 6 mRad at a wavelength of
850 nm, the grating period d will be given by d sin
.theta.=.lamda., where .theta.=6 mRad, .lamda.=850 nm. From this
d=0.14 mm. Therefore to achieve this angular resolution of 6 mRad
the beam width at the DOE has to be at least 4.times.d=0.57 mm
[0237] Light emitters which emit coherent light beams that are
wider than the facilitating beam width may be created. However, the
physical size of such emitters, the heat which they produce or the
possibility to pack a large number of such light sources into a
compact packaging may render utilization of such light emitters
impractical for system 201. Therefore, utilization of emitters
which emit narrower light beams is investigated below with respect
to system 201.
[0238] System 201 further includes emitter array 210 which includes
a plurality of individual emitters. Emitter array 210 of system 201
is operable to emit a plurality of coherent light beams. Each
emitter 212 in emitter array 210 of system 201 is operable to emit
a light beam 110 (out of the plurality of light beams 110), which
is characterized by a native beam width. For the sake of clarity of
illustration, only two light beams 110 are illustrated in FIG.
8.
[0239] The beam diameter or beam width of an electromagnetic beam
is the diameter along any specified line that is perpendicular to
the beam axis and intersects it. Since beams typically do not have
sharp edges, the diameter can be defined in many different ways.
Some definitions of beam width which are well accepted in the art
include D4.sigma., 10/90 (or 20/80) knife-edge, 1/e2, FWHM, and
D86. It is noted that the native beam width of a light beam 110
emitted by an emitter 212 may be measured at any point between the
respective emitter 212 and the point in which that light beam 110
meets the first optical component of optical subunit 220 (e.g. a
lens, a mirror, etc.). Such native beam widths are denoted as
native widths 20 in FIG. 8.
[0240] Optical subunit 220 in system 201 (which may be an optical
assembly which includes a plurality of optical elements) is
operable to transform the plurality of light beams 110 to provide a
plurality of transformed light beams 130, and to direct the
plurality of transformed light beams 130 onto the diffractive
optical element 230, resulting in providing of a structured light
pattern 150 (not illustrated) by optical system 201.
[0241] In system 201, each of the transformed light beams 130 is
characterized by an expanded beam width (denoted 30) that is wider
than the native beam width 20 of the corresponding light beam 110.
Furthermore, the expanded beam widths 30 of the plurality of
transformed light beams 130 are larger than the facilitating beam
width.
[0242] The expansion of light beams 110 may enable utilizing light
sources whose native beam width is below the aforementioned
facilitating beam width of DOE 230 (e.g. which in turn may enable,
for example, using emitters of smaller dimensions, using emitters
which produce relatively less heat, pack a large number emitters
into a tight volume, and so on).
[0243] Optionally, each emitter 212 in emitter array 210 is
operable to emit a light beam whose native beam width is narrower
than the facilitating beam width. Optionally, each emitter 212 in
emitter array 210 is operable to emit a light beam whose native
beam width is narrower than the facilitating beam width by a factor
of at least 2. Optionally, each emitter 212 in emitter array 210 is
operable to emit a light beam whose native beam width is narrower
than the facilitating beam width by a factor of at least 5.
[0244] Optionally, each emitter 212 in emitter array 210 is
operable to emit a light beam whose native beam width is narrower
than the facilitating beam width by at least one order of
magnitude.
[0245] For example, the native beam widths 20 of light beams 110 in
system 201 may be 10-100 micrometer, while the expanded beam widths
30 of the corresponding transformed light beams 130 may be 100-1000
micrometer. Optionally, the expanded beam widths 30 of transformed
light beams 130 in system 201 may be at least 3 times larger than
the corresponding native beam widths 20 of the corresponding light
beams 110.
[0246] An example of utilization for the expansion of beams for the
miniaturization of system 201 is the ability to pack the emitters
212. For example, optionally for each individual emitter 212 of
emitter array 210 there is at least one other individual emitter
212 of the emitter array 210 positioned at a distance which is at
least 10 times smaller than any beam-width 30 of any transformed
light beam 130 out of the plurality of transformed light beams
130.
[0247] As discussed with respect to system 200, optionally optical
subunit 220 of system 201 is an optical assembly which includes a
plurality of optical elements. Furthermore, this plurality of
optical element may have a common optical axis common to the
plurality of optical elements.
[0248] As discussed above (e.g. with respect to FIGS. 3A and 3B),
emitter array 210 and optical subunit 220 may be positioned
relative to one another such that optical subunit 220 further
transforms the plurality of light beams (in addition to expanding
the width of the beams) by deflecting the plurality of light beams
110, so that the plurality of transformed light beams 130 are
projected onto diffractive optical element 230 at different angles
of incidence, resulting in providing of a plurality of light
patterns 140 by diffractive optical element 230 (where the
structured light pattern 150 includes these plurality of light
patterns 140).
[0249] It is noted that in addition to expanding the width of the
light beams 110, optical subunit 220 may transform the light beams
110 in additional ways, which would contribute to the efficiency
and quality of the projection of system 201 even more. For example,
optical subunit 220 may further transform the light beams 110 in
order to reduce their divergence (collimating the beams).
[0250] Each emitter 212 in the emitter array 210 is operable to
emit a light beam 110 (out of the plurality of light beams 110)
which is characterized by a divergence (referred to below as the
first beam divergence of the light beam 110 of this emitter 212).
Optionally, optical subunit 220 of system 201 is further operable
to transform the plurality of light beams 110, so that each of the
transformed light beams 130 is characterized by a second beam
divergence that is smaller than the first beam divergence of the
corresponding light beam 110. The reduction of the divergence of
the light beams 110 is further investigated with respect to system
202.
[0251] FIG. 9 is a functional block diagram illustrating an example
of optical system 202 in accordance with examples of the presently
disclosed subject matter. It is noted that in further examples,
system 202 may be implemented with any of the variations of system
200 discussed above. It is however noted that system 202 may
incorporate any of the features, components and abilities discussed
above with respect to system 200 as general. Furthermore, system
202 may incorporate any of the features, components and abilities
discussed below with respect to systems 201, 203, 204 and 205. The
components of system 202 are denoted using the same numeral
reference used for the components of system 200, and the variations
discussed with respect to these components in other parts of the
document may also pertain, mutatis mutandis, to system 202.
[0252] System 202 is an optical system which includes a diffractive
optical element (DOE 230), capable of diffracting an incident
coherent light beam to provide a light pattern. It is noted that
while not necessarily so, the contrast of the light pattern
provided by the DOE 230 has a negative correlation with the
divergence of the incident light beam. That is, the lesser the
divergence of the incident light beam, the better contrast will the
DOE be able to produce.
[0253] Light emitters which emit coherent light beams and whose
emitted light coherent light beams are characterized by relatively
low divergence can be created. However, the physical size of such
emitters, the heat they produce or the possibility to pack a large
number of such light sources into a compact packing may render
utilization of such light emitters impractical for system 202.
Therefore, utilization of emitters which emit light beams with
divergence that is larger than the divergence of the light beams
which ultimately reaches the DOE is investigated below with respect
to system 202.
[0254] System 202 is an optical system, which includes at least
diffractive optical element 230 (capable of diffracting an incident
coherent light beam to provide light pattern 150), emitter array
210 which includes a plurality of individual emitters 212, and
optical subunit 230.
[0255] As aforementioned, each emitter 212 in emitter array 210 is
operable to emit a light beam 110, out of the plurality of light
beams 110, which is characterized by a first beam divergence. Such
first beam divergence is denoted first beam divergence 40 in FIG.
9.
[0256] In system 202, emitter array 210 includes a plurality of
individual emitters 212. Each emitter 212 in emitter array 210 is
operable to emit a light beam 110 which is characterized by a first
beam divergence. Optical subunit 220 in system 202 is operable to
transform a plurality of light beams 110 emitted by emitter array
210, wherein each of the transformed light beams 130 is
characterized by a second beam divergence that is smaller than the
first beam divergence of the corresponding light beam 110. DOE 230
is capable of diffracting the transformed light beams to provide
light patterns.
[0257] Optical subunit 220 is operable to transform the plurality
of light beams 110 to provide a plurality of transformed light
beams 130 and to direct the plurality of transformed light beams
130 onto diffractive optical element 230, to thereby provide
structured light pattern 150 by optical system 202. Each of these
transformed light beams 130 provided by optical subunit 220 of
system 202 is characterized by a second beam divergence (denoted 50
in FIG. 9) that is smaller than the first beam divergence 40 of the
corresponding light beam 110.
[0258] Optionally, a facilitating beam divergence (.theta.max) is
defined for DOE 230 so that incidence upon the DOE 230 of coherent
light beams whose divergence is lower than the facilitating beam
divergence (.theta.beam<.theta.max) results in provisioning of
light patterns whose contrast meets a light pattern target contrast
criteria. In such case, system 202 may be designed so that the
second beam divergences 50 of the plurality of transformed light
beams 130 in system 202 are lower than the facilitating beam
divergence (.theta.max). The light beams have to be wider than the
facilitating beam width.
[0259] Therefore, transforming the light beams 110 by the optical
subunit 220 of system 202 enables to achieve better contrast
compared to a design that does not include the optical unit 220.
Also, by transforming the light beams 110, it is possible to
utilize emitters 210 which are capable of emitting light beams 110
that are characterized by larger divergence than would otherwise be
required, and still receive a structured light pattern with high
contrast. Furthermore, it is noted that emitters with narrow light
beams (whose use for miniaturization etc. is discussed with respect
to system 201 above) can also have larger divergence than is
possible to achieve with emitters that produce wider light beams.
Therefore, reducing the divergence of light beams 110 by optical
subunit 220 enables utilizing emitters with divergence that is
larger than the facilitating beam divergence, and also emitters
which emit narrow light beams.
[0260] Optionally, each emitter 212 in emitter array 210 is
operable to emit a light beam 110 whose first beam divergence 40 is
larger than the facilitating beam divergence (.theta.max) by at
least one order of magnitude.
[0261] Optionally, each emitter 212 in emitter array 210 is
operable to emit a light beam 110 whose native beam width 20 is
narrower than the facilitating beam width by at least one order of
magnitude, and whose first beam divergence 40 is larger than the
facilitating beam divergence (.theta.max) by at least one order of
magnitude.
[0262] Optionally, optical subunit 220 may be operable to reduce a
divergence of each light beam 110 out of the plurality the light
beams 110 by at least 90% to provide the respective transformed
light beam 130.
[0263] For example, the first beam divergences of the light beams
110 emitted by emitter array may be 100 mrad-500 mrad, while the
second beam divergences of the corresponding light beams may be 5
mrad-50 mrad.
[0264] As aforementioned, optionally optical subunit 220 is
operable to transform the plurality of light beams 110 to provide
the plurality of transformed light beams 130 using transforming
optical components of the optical subunit 220 which are common to
the plurality of light beams 110.
[0265] As also discussed above, optionally emitter array 210 and
optical subunit 220 are positioned relative to one another such
that optical subunit 220 further transform the plurality of light
beams 110 by deflecting the plurality of light beams 110 to thereby
cause the plurality of transformed light beams 130 to be projected
onto diffractive optical element 230 at different angles of
incidence, resulting in providing of a plurality of light patterns
140 by the diffractive optical element.
[0266] As aforementioned, packing many individual emitters in a
small emitter array may improve the quality of the structured light
pattern 150 projected by system 200 in many ways, such as improving
its angular resolution, its speckle noise, etc. It may also
contribute to the miniaturization of system 200, to lowering the
system's 200 energy consumption, etc.
[0267] FIG. 10 is a functional block diagram illustrating an
example of optical system 203 in accordance with examples of the
presently disclosed subject matter. It is noted that system 203 may
be implemented with any of the variations of system 200 discussed
above. It is however noted that system 203 may incorporate any of
the features, components and abilities discussed above with respect
to system 200 as general. Furthermore, system 203 may incorporate
any of the features, components and abilities discussed below with
respect to systems 201, 202, 204 and 205. The components of system
203 are denoted using the same numeral reference used for the
components of system 200, and the variations discussed with respect
to these components in other part of the document may also pertain,
mutatis mutandis, to system 203.
[0268] System 203 includes at least (a) diffractive optical element
230 which is capable of diffracting an incident coherent light beam
to provide a light pattern, (b) emitter array 210 which includes a
plurality of individual emitters 212 (the emitter array 210 is
operable to emit a plurality of coherent light beams), and (c)
optical subunit 220.
[0269] In system 203, emitter array 210 includes a plurality of
individual emitters 212. Each emitter 212 in the emitter array 210
is operable to emit a light beam 110. Optical subunit 220 in system
203 is operable to: a. transform a plurality of light beams 110
emitted by the emitter array 210, wherein the transformation
includes expansion and/or collimation of the plurality of light
beams 110; and b. direct the plurality of transformed light beams
onto the diffractive optical element at different angles of
incidence, resulting in providing of a plurality of light patterns
by the diffractive optical element.
[0270] DOE 230 in system 203 is capable of diffracting the
transformed light beams to provide light patterns;
[0271] Furthermore, in emitter array 210 of system 203, for each
individual emitter 212 there is at least one other individual
emitter 212 of emitter array 210 which is positioned at a distance
which is smaller than any beam width 30 of any transformed light
beam 130 out of the plurality of transformed light beams 130. The
distance between any two emitters is denoted 60 in FIG. 10.
[0272] As discussed above with respect to system 200, optionally
optical subunit 220 is operable to transform the plurality of light
beams 110 to provide the plurality of transformed light beams 130
using transforming optical components of optical subunit 220 which
are common to the plurality of light beams 110.
[0273] FIGS. 12A through 12G include diagrams which are related to
possible distortions in the light patterns generated by system 200,
and ways to reduce such distortion, in accordance with examples of
the presently disclosed subject matter. It is noted that distortion
and other problems may occur throughout the generated light
pattern, and especially at the edge of the field of projection of
the light pattern. In the discussion pertaining to FIGS. 12A
through 12G it is assumed that the light pattern 150 includes a
plurality of points, and that structured light pattern 150 is
constructed from a plurality of light patterns 140 (as discussed
above, e.g. with respect to FIGS. 4A, 4B and 4C. The exemplary
light pattern 140 used in the examples of FIGS. 12A through 12G is
designed to include a plurality of regularly spaced points, as
exemplified in FIG. 12A. In the following discussion pertaining to
FIGS. 12A through 12G, light pattern 140 is also referred to as
"tile pattern".
[0274] In the present example, the tile pattern 140 at the center
of the field will form a nearly rectangular shape containing
regularly spaced points, whereas at the edge of the field the
points of each tile pattern will form a nearly parallelogram shape,
as exemplified in FIG. 12B. The reason for this distortion of the
tile pattern is that for different light beams emitted by different
emitters 212 of emitter array 210, the distance of the chief ray of
the light beams from the DOE to the object plane is very different
for tile patterns located in different field points. It is noted
that the distortion assumes a non-spherical plane on which the
structured light pattern 150 is projected. If the object plane was
spherical then the distance from DOE 230 to the object on which the
light pattern is projected would have been the same.
[0275] In the example of FIGS. 12A through 12G, the tile pattern
includes forty nine points formed by diffraction through DOE 230.
The tile pattern of FIG. 14A is formed using a light beam whose
chief ray angle (CRA) is zero. The source light beam in the example
of FIG. 14A is a simple laser beam parallel to the optical axis.
The source light beam in the example of FIG. 12B is a simple laser
beam which propagates towards the DOE diagonally to the optical
axis.
[0276] FIG. 12C illustrates a simplified configuration of system
200 which was used to generate the light patterns in FIGS. 12E and
12G. For simplicity of illustration, only 18 individual emitters
212 and their respective light beams are illustrated in the
following examples. As seen in FIG. 12D, out of these 18 emitters
212, 9 emitters 212 are centered about the lens (i.e. are close to
the optical axis) and 9 emitters 212 are at the edge of the field
(remotely from the optical axis). As the light beam emitted by each
emitter 212 passes through the DOE 230 (after being transformed by
optical subunit 220), it produces its own tile pattern of 49
points. FIG. 12E illustrates the projection of the tile patterns
generated by the emitters 212 of FIG. 12D on a projection plane
that is perpendicular to the optical axis.
[0277] As can be seen in FIG. 12E, the nine tile patterns 140 which
are located near the edge of the field are not rectangular (shaped
more like a parallelogram than a rectangle), and the separation
between the individual points of each tile pattern is larger than
the separation between the points in the nine central tile patterns
140. Furthermore, in all of the field, the tile patterns 140 are
not adjacent to each other, creating a discontinuity in the
structured light pattern.
[0278] As aforementioned, the individual emitters 212 of emitter
array 210 may be arranged in a non-regular (or semi-regular)
configuration. The configuration of FIG. 12F may be used to correct
a discontinuity which results in the example of FIGS. 12D and 12E
from the regular distribution of the emitters 212 in emitter array
210.
[0279] As can be seen, the distance between the nine central
emitters 212 was reduced, and is significantly smaller than the
separation between the nine remote emitters 212, near the sides of
emitter array 210. Furthermore, the nine remote emitters 212 are
not arranged in a rectangular configuration. These nine remote
emitters 212 may be arranged on a distorted grid (e.g. a regular XY
grid to which pincushion distortion was applied).
[0280] FIG. 12G illustrates structured light pattern 150 which
results from the emitters configuration of FIG. 12F. As can be
seen, the light patterns 140 in each of the clusters (the central
cluster of nine tile patterns and the remote cluster of nine tile
patterns) are adjacent to each other, without discontinuities.
[0281] Generally with respect to system 200, it is noted that the
positioning of the individual emitters 212 within emitter array 210
may be selected to reduce discontinuity between the light patterns
140 resulting from different emitters 212. Optionally the
individual emitters 212 of emitter array 210 are arranged on a
radially distorted regular grid (i.e. on a regular grid on which
radial distortion transformation was applied). Different regular
grids may be radially distorted for overcoming discontinuity--e.g.
rectangular grid, hexagonal grid, and so on.
[0282] It is further noted that processing unit 260 (if
implemented) may include algorithms which compensate for such
distortion and/or discontinuity of the structured light pattern. It
is noted that the arrangement of the individual emitters 212 may
depend not only on the distortion of the collimator lens, but also
on the distortion of the object space field of view (if known in
advance). Notably, for 3D imaging the object space field is usually
not known in advance (with the exception of calibration scenes,
etc.). The emitter array 210 may be tailored for a particular
optics of optical unit 220, any change in the optics would require
different emitter array spacing configuration in order to reduce
the distortion and the discontinuity.
[0283] FIG. 13 is a functional block diagram illustrating an
example of optical system 204 in accordance with examples of the
presently disclosed subject matter. Diagram 13.1 illustrates system
204 in a diagonal view, and diagram 13.2 illustrates system 204 in
a side view. It is noted that system 204 may be implemented with
any of the variations of system 200 discussed above. It is however
noted that system 204 may incorporate any of the features,
components and abilities discussed above with respect to system 200
as general. Furthermore, system 204 may incorporate any of the
features, components and abilities discussed below with respect to
systems 201, 202, 203 and 205. The components of system 204 are
denoted using the same numeral reference used for the components of
system 200, and the variations discussed with respect to these
components in other part of the document may also pertain, mutatis
mutandis, to system 204.
[0284] System 204 includes at least (a) diffractive optical element
230 which is capable of diffracting an incident coherent light beam
to provide a light pattern, (b) emitter array 210 which includes a
plurality of individual emitters 212 (the emitter array 210 is
operable to emit a plurality of coherent light beams), and (c)
optical subunit 220.
[0285] In system 204, the plurality of individual emitters 212 of
emitter array 210 are arranged so as to form a planar emission
plane (denoted 111), wherein each emitter in the emitter array is
operable to emit a light beam.
[0286] Emission plane 111 is a plane in which the emitting ends of
individual emitters 212 are located (as illustrated in both of
diagrams 13.1 and 13.2). Emission plane 111 is planar in the sense
that all of the emitting ends of individual emitters 212 are
located on a flat plane.
[0287] It is noted that an emitter array whose emitters are
arranged on a planar emission plane is usually simpler and cheaper
to produce than an emitter array whose emitters are arranged on a
non-flat emission plane. Furthermore, designing an emitter array
characterized by a planar emission plane is simpler and cheaper
than designing an emitter array with a non-flat emission plane.
[0288] The present disclosure teaches how to use an optical subunit
220 so as to enable using an emitter array with a planer emission
plane while overcoming various optical issues. Further discussion
is presented above, e.g. with respect to FIGS. 12A through 12G.
[0289] Optical subunit 220 in system 204 is operable to: (a)
transform a plurality of light beams emitted by the emitter array,
wherein the transformation includes expansion and/or collimation of
the plurality of light beams; and (b) to direct the plurality of
transformed light beams onto the diffractive optical element at
different angles of incidence, resulting in providing of a
plurality of light patterns by the diffractive optical element. DOE
230 of system 204 is capable of diffracting the transformed light
beams to provide light patterns.
[0290] As discussed with respect to system 200, optionally optical
subunit 220 includes a plurality of optical elements having a
common optical axis common to the plurality of optical
elements.
[0291] As discussed with respect to system 200, optionally optical
subunit 220 is operable to transform the plurality of light beams
110 to provide the plurality of transformed light beams 130 using
transforming optical components, out of the plurality of optical
components, which are common to the plurality of light beams.
[0292] As discussed with respect to system 200, optionally emitter
array 210 and optical subunit 220 are positioned relative to one
another such that optical subunit 220 further transform the
plurality of light beams 110 by deflecting the plurality of light
beams 110 so that the plurality of transformed light beams 130 are
projected onto DOE 230 at different angles of incidence, resulting
in providing of a plurality of light patterns by DOE 230.
[0293] FIG. 14 is a functional block diagram illustrating an
example of optical system 205 in accordance with examples of the
presently disclosed subject matter. It is noted that system 205 may
be implemented with any of the variations of system 200 discussed
above. It is however noted that system 204 may incorporate any of
the features, components and abilities discussed above with respect
to system 200 as general. Furthermore, system 205 may incorporate
any of the features, components and abilities discussed below with
respect to systems 201, 202, 203 and 204. The components of system
205 are denoted using the same numeral reference used for the
components of system 200, and the variations discussed with respect
to these components in other part of the document may also pertain,
mutatis mutandis, to system 204.
[0294] System 205 includes at least (a) diffractive optical element
230 which is capable of diffracting an incident coherent light beam
to provide a light pattern, (b) emitter array 210 which includes a
plurality of individual emitters 212 (the emitter array 210 is
operable to emit a plurality of coherent light beams), and (c)
optical subunit 220.
[0295] In system 205, the combination of optical subunit 220 and
DOE 230 is characterized by a distortion function. The plurality of
individual emitters 212 in system 205 are arranged in a non-uniform
configuration whose relation to a predefined uniform grid is an
inverse function of the distortion function. It is noted that in
different systems, the relative amount of distortion caused by the
optical subunit 220 and the DOE 230 may vary, and optionally all of
the distortion may be caused by DOE 230, without additional
distortion caused by optical subunit 230. In such case, the
distortion function may characterize the DOE 230.
[0296] An example of the distortion function of optical subunit 220
is presented in FIGS. 12D and 12E. As can be seen, a regular grid
of individual emitters 212 in FIG. 12D is transformed into a
non-regular array of illumination. Method 900 in FIG. 25 discloses
a method which may be used to determine the distortion function,
and based on which to determine a non-uniformed configuration which
may be used for the individual emitters of system 205.
[0297] As discussed with respect to system 200, optical subunit 220
of system 205 may be operable to direct the plurality of
transformed light beams onto the diffractive optical element 230 at
different angles of incidence, resulting in providing of a
plurality of light patterns by diffractive optical element 230.
[0298] FIG. 15 is a functional block diagram illustrating an
example of optical system 200, in accordance with examples of the
presently disclosed subject matter. In FIG. 15 there is presented a
possible utilization of the projection of the structured light
pattern 150 in system 200, for capturing three dimensional (3D)
images. The capturing of 3D images by system 200 is facilitated by
determining range parameters for objects imaged in different pixels
of the image. It is noted that these possible uses are offered by
way of a non-limiting example, as many other uses will present
themselves to a person who is of skill in the art. Furthermore,
while the functionalities of utilizing the projection of system 200
are discussed as being implemented by components of the same system
200, it will be clear that such functionalities may also be
implemented by an external system and with additional, fewer or
other components for utilizing the projection.
[0299] The following discussion relates to a system for managing 3D
capture. It will be clear to a person who is of skill in the art
that the following discussion is also applicable to methods and
computer program products for managing 3D capture, mutatis
mutandis, and that the latter are not discussed in detail for
reasons of brevity.
[0300] According to examples of the presently disclosed subject
matter, managing the 3D capture can include managing use of
resources in a mobile computing device, more particularly, a mobile
communication device such as a smartphone, a tablet and/or their
likes according to predefined rules or criteria. In further
examples of the presently disclosed subject matter, managing the 3D
capture can include managing use of one or more 3D capturing
resources in a mobile communication device. Yet further by way of
example, managing the 3D capture can include managing one or more
of: power consumption, a memory and/or storage utilization,
allocation communication bandwidth consumption, allocation of
processing resources (e.g., CPU cycles) etc. In the following
description, by way of non-limiting example for a mobile computing
device, reference is typically made to a mobile communication
device.
[0301] Throughout the following description, reference is made to
the term "3D capture". The term 3D capture relates to a
technological process which involves utilizing a plurality of
resources of a mobile communication device to obtain depth or range
data (3D data) with respect to a certain scene. Thus, according to
examples of the presently disclosed subject matter, managing 3D
capture can include managing operation of at least one resource
that is involved in the 3D capture or managing operation of at
least one software feature of the 3D capture. It would be
appreciated that at least in some respects, in some cases, or under
certain conditions modifying the operation of a resource that is
involved in the 3D capture can affect the operation of at least one
software feature of the 3D capture, and vice versa.
[0302] Referring to FIG. 15 (and to system 200 generally), it is
noted that system 200 may be implemented as a mobile communication
device, such as a smartphone, a lap-top computer or another
hand-held device. As can be seen in Fig. Error! Reference source
not found., and by way of example, system 200 may include a various
components that are capable of providing 3D depth or range data. In
the example of FIG. 15 there is shown a configuration of system 200
which includes an active stereo 3D camera 10, but in further
examples of the presently disclosed subject matter other known 3D
cameras can be used. Those versed in the art can readily apply the
teachings provided in the examples of the presently disclosed
subject matter to other 3D camera configurations and to other 3D
capture technologies.
[0303] By way of example, the 3D camera 10 can include: a 3D
capture sensor 12 (which may optionally be part of the
aforementioned imaging sensing unit 250 or replace it), a driver
14, a 3D capture processor 16 (which may optionally be part of the
aforementioned processing unit 250 or replace it). System 200 also
includes a projection module 18, which includes emitter array 210,
optical subunit 220 and DOE 230. Optionally, projection module 18
may further include output optics 240.
[0304] In this example, the projection module 18 is configured to
project a structured light pattern and the 3D capture sensor 12 is
configured to capture an image which corresponds to the reflected
pattern, as reflected from the environment onto which the pattern
was projected. U.S. Pat. No. 8,090,194 to Gordon et. al. describes
an example structured light pattern that can be used in a
projection module component of a 3D camera, as well as other
aspects of active stereo 3D capture technology and is hereby
incorporated into the present application in its entirety.
International Application Publication No. WO2013/144952 describes
an example of a possible projection module design (also referred to
as "flash design"), and is hereby incorporated by reference in its
entirety.
[0305] By way of example, emitter array 210 which is included in
the projection module 18 may include an IR light source, such that
it is capable of projecting IR radiation or light, and the 3D
capture sensor 12 can be and IR sensor, that is sensitive to
radiation in the IR band, and such that it is capable of capturing
the IR radiation that is returned from the scene. The projection
module 18 and the 3D capture sensor 12 are calibrated. According to
examples of the presently disclosed subject matter, the driver 14,
the 3D capture processor 16 or any other suitable component of the
system 200 can be configured to implement auto-calibration for
maintaining the calibration among the projection module 18 and the
3D capture sensor 12.
[0306] The 3D capture processor 16 can be configured to perform
various processing functions, and to run computer program code
which is related to the operation of one or more components of the
3D camera. The 3D capture processor 16 can include memory 17 which
is capable of storing the computer program instructions that are
executed or which are to be executed by the processor 16.
[0307] The driver 14 can be configured to implement a computer
program which operates or controls certain functions, features or
operations that the components of the 3D camera 10 are capable of
carrying out.
[0308] According to examples of the presently disclosed subject
matter, system 200 can also include hardware components in addition
to the 3D camera 10, including for example, a power source 20,
storage 30, a communication module 40, a device processor 40 and
memory 60 device imaging hardware 110 a display unit 120 and other
user interfaces 130 . It should be noted that in some examples of
the presently disclosed subject matter, one or more components of
system 200 can be implemented as distributed components. In such
examples, a certain component can include two or more units
distributed across two or more interconnected nodes. Further by way
of example, a computer program, possibly executed by the device
processor 40, can be capable of controlling the distributed
component and can be capable of operating the resources on each of
the two or more interconnected nodes.
[0309] It is known to use various types of power sources in a
mobile communication device. The power source 20 can include one or
more power source units, such as a battery, a short-term high
current source (such as a capacitor), a trickle-charger, etc.
[0310] The device processor 50 can include one or more processing
modules which are capable of processing software programs. The
processing module can each have one or more processors. In this
description, the device processor 50 different types of processor
which are implemented in system 200, such as a main processor, an
application processor, etc.). The device processor 50 or any of the
processors which are generally referred to herein as being included
in the device processor can have one or more cores, internal memory
or a cache unit.
[0311] The storage unit 30 can be configured to store computer
program code that is necessary for carrying out the operations or
functions of system 200 and any of its components. The storage unit
30 can also be configured to store one or more applications,
including 3D applications 80, which can be executed on system 200.
In a distributed configuration one or more 3D applications 80 can
be stored on a remote computerized device, and can be consumed by
system 200 as a service. In addition or as an alternative to
application program code, the storage unit 30 can be configured to
store data, including for example 3D data that is provided by the
3D camera 10.
[0312] The communication module 40 can be configured to enable data
communication to and from the mobile communication device. By way
of example, examples of communication protocols which can be
supported by the communication module 40 include, but are not
limited to cellular communication (3G, 4G, etc.), wired
communication protocols (such as Local Area Networking (LAN)), and
wireless communication protocols, such as Wi-Fi, wireless personal
area networking (PAN) such as Bluetooth, etc.
[0313] It should be noted that that according to some examples of
the presently disclosed subject matter, some of the components of
the 3D camera 10 can be implemented on the mobile communication
hardware resources. For example, instead of having a dedicated 3D
capture processor 16, the device processor 50 can be used. Still
further by way of example, system 200 can include more than one
processor and more than one type of processor, e.g., one or more
digital signal processors (DSP), one or more graphical processing
units (GPU), etc., and the 3D camera can be configured to use a
specific one (or a specific set or type) processor(s) from the
plurality of device 100 processors.
[0314] System 200 can be configured to run an operating system 70.
Examples of mobile device operating systems include but are not
limited to: such as Windows Mobile.TM. by Microsoft Corporation of
Redmond, Wash., and the Android operating system developed by
Google Inc. of Mountain View, Calif.. It is noted that if system
200 is not a mobile system, other operating systems may be used
(e.g. Windows, Linux, etc.).
[0315] The 3D application 80 can be any application which uses 3D
data. Examples of 3D applications include a virtual tape measure,
3D video, 3D snapshot, 3D modeling, etc. It would be appreciated
that different 3D applications can have different requirements and
features. A 3D application 80 may be assigned to or can be
associated with a 3D application group. In some examples, the
device 100 can be capable of running a plurality of 3D applications
80 in parallel.
[0316] Imaging hardware 110 can include any imaging sensor, in a
particular example, an imaging sensor that is capable of capturing
visible light images can be used. According to examples of the
presently disclosed subject matter, the imaging hardware 110 can
include a sensor, typically a sensor that is sensitive at least to
visible light, and possibly also a light source (such as one or
more LEDs) for enabling image capture in low visible light
conditions. According to examples of the presently disclosed
subject matter, the device imaging hardware 110 or some components
thereof can be calibrated to the 3D camera 10, and in particular to
the 3D capture sensor 12 and to the projection module 18. It would
be appreciated that such a calibration can enable texturing of the
3D image and various other co-processing operations as will be
known to those versed in the art.
[0317] In yet another example, the imaging hardware 110 can include
a RGB-IR sensor that is used for capturing visible light images and
for capturing IR images. Still further by way of example, the
RGB-IR sensor can serve as the 3D capture sensor 12 and as the
visible light camera. In this configuration, the driver 14 and the
projection module 18 of the 3D camera, and possibly other
components of the device 100, are configured to operate in
cooperation with the imaging hardware 110, and in the example given
above, with the RGB-IR sensor, to provide the 3D depth or range
data.
[0318] The display unit 120 can be configured to provide images and
graphical data, including a visual rendering of 3D data that was
captured by the 3D camera 10, possibly after being processed using
the 3D application 80. The user interfaces 130 can include various
components which enable the user to interact with system 200, such
as speakers, buttons, microphones, etc. The display unit 120 can be
a touch sensitive display which also serves as a user
interface.
[0319] The 3D capture processor 16 or the device processor 50 or
any sub-components or CPU cores, etc. of such processing entities
can be configured to process a signal that is received from the 3D
capture sensor 12 or from the device imaging hardware 110, in case
the device imaging hardware 110 is capable of and is configured to
serve the 3D camera 10. For convenience, in the following
description, the core 3D capture functions shall be attributed, in
a non-limiting manner, to the 3D capture processor 16 and to the 3D
capture processor 16. However, it would be appreciated that the
functionality and task allocation between the various components
and sub components of system 200 are often a design choice.
[0320] According to examples of the presently disclosed subject
matter, the 3D capture processor 16 can be configured to collect
imaging data, process the imaging data, analyze the imaging data,
produce imaging results, imaging content, and/or imaging display,
etc.
[0321] According to examples of the presently disclosed subject
matter, the 3D capture processor 16 can receive as input an IR
image and calibration information. By way of example, the
calibration information may relate to IR sensor (as an example of a
3D capture sensor) and projector (such as the projection module
18). In some examples of the presently disclosed subject matter,
the 3D capture processor 16 can also receive as input a color
image, e.g., from the device imaging hardware 110, and a color
camera--IR camera calibration information.
[0322] By way of example, the processing that is carried out by the
3D capture processor 16 can include pre-processing, optical
character recognition (OCR), error correction and triangulation.
The pre-processing function can include operations for removing
sensor noise and for improving signal quality, e.g., by resolving
optical issues, such as speckles. The OCR function translates areas
in the image to one of a plurality of code words that were used in
the pattern that was projected by the projection module 18 and
which was captured by the 3D capture sensor 12. The error
correction operation can include computations which use
pre-existing knowledge on the projected pattern/code to correct
erroneous labeling of code words or of features of code words
(which can lead to changing of a label of one or more code words).
The triangulation function takes into account the imaging geometry
to extract the depth information. An example of a triangulation
procedure that is made with reference to active triangulation
methods is provided in U.S. Pat. No. 8,090,194 to Gordon et al.
[0323] According to examples of the presently disclosed subject
matter, the 3D capture processor 16 can also perform a color
projection function, whereby the color from a color sensor (e.g.,
from the device imaging hardware 110) is projected onto the 3D
data. It would be appreciated that the color projection function
(as any other function described here with reference to the 3D
capture processor 16) can be carried out by the device processor 50
or any processing component thereof.
[0324] Additional processes which may involve processing operations
and which can be implemented as part of a 3D data processing
pipeline for certain 3D applications can (but not necessarily)
include some (e.g., one, two, three, . . . ) of the following: live
system control (e.g., auto gain, auto exposure, control of active
source power and pulse duration, etc.), point cloud registration,
denoising, feature classification, feature tracking, various 3D
vision uses, passive camera processing (e.g., pose estimations,
shape from motion etc.), inertial measurement unit (IMU) processing
(e.g, kalman filters), time stamping, ISP functions (demosaic, gama
correction), compression, calibration quality monitoring, etc. It
would be appreciated that the above operations can be carried out
on the 3D capture processor 16, on the device processor 50 or on
both (the processing tasks can be divided among the various
processing resource, either in advance or in real-time).
[0325] According to examples of the presently disclosed subject
matter, the 3D camera 10, after processing of the signal from the
sensor 12 and possibly from other sources, can be configured to
provide as output one or more of the following: a set of 3D points,
typically with normals (point cloud), where the normals can be
computed using adjacent points; a textured mesh--triangulation
(generating polygonal surface) using adjacent; depth map with color
map (color projection). Those versed in the art would appreciate
that additional outputs can be provided by the 3D camera 10. As
mentioned above, some of the processing attributed in some examples
of the presently disclosed subject matter to the 3D camera 10 and
to the 3D capture processor 16 can be carried out outside the 3D
camera 10, and in particular by the device processor 50, and so
some of the output which are attributed here to the 3D camera 10
can be generated outside what is referred to as the 3D camera in
the examples shown in FIG. 15 and in the description of FIG. 15
provided herein.
[0326] According to examples of the presently disclosed subject
matter, the device processor 50, possibly in cooperation with the
3D capture processor 16, can be configured to determine or receive
data with respect to the state of the resources of the mobile
communication system 100. The resources state data can be organized
in any suitable form. For example, related or alternative resources
can be grouped, resources which are linked by some tradeoff can be
linked, resources whose usage crossed some threshold can be
grouped, etc.
[0327] According to examples of the presently disclosed subject
matter , in addition to the usage state information, the device
processor 50 can be configured to obtain or receive, e.g., from the
memory 60, additional information which can be useful for determine
the usage state of one or more resources of system 200. For
example, the device processor 50 can obtain data which relates to
expected resources usage, for example, as result of scheduled tasks
or based on statistics with respect to the device 100 or its
resources behavior in terms of resource usage and/or based on
statistics with respect to the behavior of applications running on
the device in terms of resource usage. In another example, expected
resources usage can relate to tasks that are expected to be carried
out, either as a result of processes that are already running one
the mobile communication device, or for any other reason.
[0328] According to examples of the presently disclosed subject
matter, the term "resource availability profile" is used in the
description and in the claims to describe the data that is used in
the mobile communication device to describe the current or expected
state of one or more resources of the mobile communication device,
in particular to describe the state of the resources that are
associated with the operation of a 3D application, or which are
expected to be effected by the operation of a 3D application or any
of its features.
[0329] According to examples of the presently disclosed subject
matter, the device processor 50 can be configured to continuously
monitor the state of the resources of system 200 and can update to
resource availability profile accordingly. In further examples of
the presently disclosed subject matter the device processor 50 can
be configured to routinely monitor the resources state and update
the resource availability profile, where the timing of the update
is either determine according to predefined intervals, or is
determined based on some input that is received at the device
processor. In yet another example, the device processor 50 updates
to resource availability profile when a certain event occurs, such
as an event which effects the availability of at least one resource
of the mobile communication device.
[0330] Throughout the description and in the claims reference is
made to the term "3D application". The term 3D application as used
herein relates to a computer program code that can run as an
application on a mobile communication platform (whether hosted
locally or whether hosted remotely and consumed as a service on a
mobile communication device), and which computer program code
embodies at least one feature which uses 3D data, in particular 3D
data that is provided by or obtained from a 3D camera. Such a
feature is termed in the description and in the claims as a 3D
capture feature. Many examples of 3D applications exist in the
market and the following are a small sample of which: a virtual
tape measure, a room modeling environment, 3D segmentation and
model creation, augmented reality games, etc.
[0331] It would be appreciated that a 3D application, or a 3D
capture feature of a 3D application can have certain attributes
characteristics and requirements. Furthermore, in order to enable,
support and/or execute different 3D capture features, different
resources (hardware resource but possibly also software resources)
allocation requirements can exist (including different levels of a
given resource), or from another perspective, or according to
different implementations, different 3D capture features can
consume different resources (including different levels of a given
resource).
[0332] For example, assume a 3D conferencing application having a
full-view feature and a face-only feature, where the full scene
feature involves capturing and processing 3D data from the entire
field of view of the sensor, and the face-only feature involves
utilizing only the resources that are required for obtaining 3D
data of an area in the scene where the face of a person facing the
3D capture sensor is detected. Among the two features, it is highly
probable that the full view feature of the 3D capture application
will consume greater processing, memory and power resources
compared to the face only feature.
[0333] According to examples of the presently disclosed subject
matter, a given feature of a given 3D application 80 can be
associated with a particular part of the software program code of
the 3D application. Alternatively or additionally, a feature of a
3D application 80 can be associated with a particular resource,
such a particular hardware component or a particular software
program code external to 3D application 80 and running on system
200. For example, a feature of a 3D application can be associated
with an inertial measurement unit (not shown) of system 200.
[0334] According to examples of the presently disclosed subject
matter, for each feature there can be provided a cost measure. The
term "cost measure" as used herein and in the claims relates to a
measure of a feature's estimated, expected or measured consumption
of a given resource or of a resource group, or of one resource from
a resource group, or the measure can be global measure of the
feature's resource consumption. In yet further example, the cost
measure can relate to the feature's estimated, expected or measured
consumption of a resource or resources at a given mode of the
respective 3D capture application.
[0335] By way of example, the cost measure of each feature can
include a plurality of measures for a plurality of resources. Still
further by way of example, the cost measure can include measures
for alternative resources, and such measures and the resources with
which they are associated can be indicated as alternatives. It
would be noted that providing such alternative measures can enable
preforming various tradeoff computations including with respect to
different configurations of a given feature, and in another
example, with respect to implementation of different features in
different 3D applications or in different operational mode of a
given (the same) 3D application.
[0336] Furthermore, it is possible that two or more 3D applications
which are functionally connected to one another would be executed
in system 200, and the relation between the 3D applications can be
indicated, e.g., to the device processor 50, and the device
processor 50 can be configured to take into account the relations
and cross effect of the related 3D applications of some features
thereof when processing a cost measure of a given feature of one of
the related 3D applications.
[0337] By way of example the cost measure of a given 3D application
feature can be provided as explicit data that is stored as part of
the feature program code, or that is otherwise associated with the
feature program code. In a further example, the cost measure of a
given 3D application feature can be determined (e.g., calculated)
based on previous behavior of the feature and of one or more
resources which are utilized to enable the feature. In yet further
examples, the cost measure of a given 3D application feature can be
determined based on statistical data, for example, based on the
resource consumption of related features, possibly of related 3D
applications, and possibly also under similar operating conditions,
on similar mobile communication devices, etc.
[0338] The cost measure can be provided in various forms. For
example, the cost measure can include information related to an
amount or level of power (electricity) consumption, capacity
consumption (e.g. consumption of processing power, consumption of
memory, consumption of communication bandwidth, etc.). In another
example, the cost measure can provide a measure of an aspect of
user experience such as increased or reduced latency, frame rate,
accuracy of output, etc.
[0339] According to examples of the presently disclosed subject
matter, in addition to the cost measure of a given feature of a 3D
capture application, a functional measure can be obtained with
respect to the feature. The term "functional measure" as used
herein relates to an indication provided in respect of the
functional value of a 3D capture application feature in respect of
which the functional measure is provided. By way of example, the
functional value of a feature indicates the value, importance or
contribution of the feature to the user experience. In another
example, the functional value of a feature indicates the value,
importance or contribution of the feature for enabling additional
features of the 3D capture application, or the value, importance or
contribution of the feature for enabling features of other
applications.
[0340] Still further by way of example the functional measure of a
given feature can relate to a specific mode of operation of the
respective 3D capture application, and the functional measure
relates to the functional value of the respective feature in the
respective mode of the 3D capture application.
[0341] According to examples of the presently disclosed subject
matter, each 3D application can have at least one mode of
operation. According to examples of the presently disclosed subject
matter, a 3D application can include a live-mode. The term
"live-mode of a 3D capture application" (or "live-mode" in short)
as used in the description and in the claims relates to a mode of
the 3D application in which instant (real time or near real time,
e.g., up to 1 second of latency) feedback is provided (e.g.,
presented on a display) to a user (human or program) of the 3D
application. Still further by way of example, the feedback provided
in the live mode of the 3D application, possibly together with
additional features of the live mode, can facilitate a certain
measure of control over the an ongoing capturing process of 3D
data. For example, instant feedback which is provided by the mobile
communication device in the live mode of a 3D application can
enable modification of one or more configurations and/or features
or usage of at least one resource of the mobile communication
device the modify the results of the ongoing 3D capture process.
Examples of modification which can be enabled by the live mode
include changing an orientation of the 3D imaging components,
modifying a level of illumination provided by the projector,
changing the type of pattern that is used by the projector, and
control over software resources of the mobile communication device,
such as modifying a level of gain applied to the incoming signal
from the sensor, changing the type of error correction used in the
decoding process, etc.
[0342] According to examples of the presently disclosed subject
matter, a resource of the mobile communication device, as used
herein can relate to a component or a sub-component, a firmware
routine, or a software program running of the mobile communication
device.
[0343] As would be appreciated by those versed in the art, in case
a 3D application also operates at a non-live mode, the hardware
and/or software configuration that is used in the 3D capture
live-mode can have effect on operation of the non-live mode of the
3D application, and can have an effect on the resources that are
used in the non-live mode of the 3D application, including the
level of usage, etc. In another example, the stream of data that is
passed on a non-live mode of the 3D capture, e.g., for further
processing can also be influenced by the actual implementation of
the live-mode of the respective 3D application.
[0344] In the present disclosure and in the claims, the term
"non-live mode of a 3D application" (or "non-live mode" in short)
(e.g., latency is above 1 second or above 2-3 seconds), relates to
a mode of operation of a 3D application, other than a live mode.
According to examples of the presently disclosed subject matter, a
non-live mode of a 3D application is a mode which does not take
place concurrently with the 3D capture operation. Still by way of
example, a non-live mode of a 3D application usually involves
further utilization of resources, including, for example, further
processing of the 3D data. Still further by way of example, the
non-live mode can include further processing by the device
processor 50 of system 200 or in another example, further
processing by external (and remote) resources.
[0345] It would be appreciated that in addition to the live-mode of
a given 3D application several non-live modes can exist, each of
which can have different features, or features that have different
configurations. By way of example, the modes can differ from one
another in the amount of latency, as well as in other
characteristics.
[0346] According to examples of the presently disclosed subject
matter, a given mode of a 3D application can include at least two
features, where the two features are alternative to one another,
and wherein in the given mode of the application it is possible to
use only one of the two features. Further by way of example, each
one of the two alternative features can have a different resource
consumption.
[0347] According to examples of the presently disclosed subject
matter, two different modes of a certain 3D application can have
one or more common 3D application features. Further by way of
example, a given feature of a 3D application can have a different
configuration or different characteristics in different modes of a
given 3D application. It would be noted, a given feature which can
have different resource consumption characteristics in different
configurations of the feature. In case a 3D application that is
subject to the resource management procedure according to examples
of the presently disclosed subject matter, has identical sets of
features across two modes of operation which are used in the
resource management procedure, at least one of the features can
have a different configuration in each of the two modes of
operation.
[0348] In other examples, two different modes of a certain 3D
application can have entirely different features (none of the
features is common).
[0349] According to a further aspect of the presently disclosed
subject matter, a 3D application or given features of a 3D
application can have a local mode and a remote mode. According to
examples of the presently disclosed subject matter, in the local
mode of a given feature most, including all, of the resources which
are consumed by the feature of the 3D application reside locally or
are mostly local features of the mobile communication device, and
in the remote mode of the feature most, including all, of the
resources which are consumed by the feature are local on a remote
node (are external to the mobile communication device), e.g, most
of the resources are in the cloud.
[0350] In one example, the 3D capture processor 16 or the device
processor 50 can be configured to determine which feature of a 3D
application 80 to use in a given mode of the application, or
whether to use a feature of a first mode of the 3D application or a
feature of a second mode of the 3D application based on resource
availability information relating to an availability or to a state
of one or more resource of the mobile communication device, such
battery power, processing power, memory resources, communication
bandwidth, availability of remote processing, etc. Still further by
way of example the decision regarding which feature to use in
particular mode can be further based on one or more hardware cost
parameters which are associated with the feature.
[0351] FIG. 16 is a block diagram illustration of a system
according to examples of the presently disclosed subject matter,
including support for a remote mode of a 3D capture application
feature. As can be seen in FIG. 16, the system 900 includes a cloud
platform 910, which includes resources that enable remote
implementation of some or all of the process which are associated
with a given feature of a 3D capture application.
[0352] FIG. 17 is a flow chart illustrating an example of method
500, in accordance with examples of the presently disclosed subject
matter. Method 500 is a method for projection. It is noted that
method 500 may be implemented by a system such as systems 200, 201,
202, 203, 204 and 205, and that any variation and optional
implementation which was discussed with respect to any one of
systems 200, 201, 202, 203, 204 and 205 may also be implemented as
part of method 500, mutatis mutandis.
[0353] Stage 510 of method 500 includes emitting a plurality of
light beams. Optionally, the plurality of light beams is emitted by
a plurality of individual emitters, each of the plurality of
individual emitters emitting one of the plurality of light beams.
Referring to the examples set forth with respect to the previous
drawings, stage 510 may be implemented by emitters 212. It is noted
that emitters which are used for the emitting of stage 510 may be
included in a single emitters array (e.g. encased as a single unit,
e.g. having a united power supply), but this is not necessarily
so.
[0354] As aforementioned with respect to emitters 212, each emitter
which is used for the emitting of stage 510 may be a
vertical-cavity surface-emitting laser (VCSEL) emitter, but this is
not necessarily so, and other type of emitters (and especially
other laser emitters) may be used.
[0355] Stage 520 of method 500 includes transforming the plurality
of light beams. Stage 520 includes at least one of stages 521 of
expanding the plurality of light beams, and/or stage 522 of
collimating of the plurality of light beams. Referring to the
examples set forth with respect to the previous drawings, stage 520
may be implemented by optical subunit 220. As aforementioned with
respect to optical subunit 220, the optical subunit used for the
transforming may include a plurality of optical elements having a
common optical axis common to the plurality of optical elements.
The common optical axis may be folded once or more, but this is not
necessarily so.
[0356] Stage 540 of method 500 includes diffracting the transformed
light beams by a diffractive optical element (DOE) to provide light
patterns. Stage 540 may include diffracting the transformed light
beams by the DOE to provide a structured light pattern which
includes the light pattern provided by diffraction of each of the
transformed light beams. Referring to the examples set forth with
respect to the previous drawings, stage 540 may be implemented by
DOE 230.
[0357] Stage 540 may be preceded by stage 530 of directing the
transformed light beams toward the DOE. Stage 530 is illustrated,
for example, in FIG. 18. Referring to the examples set forth with
respect to the previous drawings, stage 530 may be implemented by
optical subunit 220.
[0358] Optionally, stage 520 of transforming may be executed by a
telecentric optical subunit. Optionally, the transforming of stage
520 may be executed by an optical subunit, wherein the emitting is
executed by a plurality of individual emitters which are positioned
on a focal plane of the optical subunit.
[0359] Optionally, the method may include transforming the
plurality of light beams which propagates in substantially parallel
paths to an optical subunit which executes the transforming.
Optionally, these parallel paths may be common to an optical axis
of the optical subunit.
[0360] FIG. 18 is a flow chart illustrating an example of method
500, in accordance with examples of the presently disclosed subject
matter. It is noted that not all of the stages which are
illustrated in FIG. 18 should necessarily be implemented together,
and that any combination of any of the optional stages may be
implemented.
[0361] Optionally, stage 510 may include stage 511 of emitting the
plurality of light beams by an emitter array including a plurality
of emitters which are arranged in non-uniform spacing between the
emitters (i.e. in spaces which differ in dimension, e.g. depending
on the distance of an individual emitter from the optical axis).
This may be used to improve the tiling between the projected light
patterns, e.g. as discussed with respect to FIGS. 12A-12G.
[0362] Referring to stage 540 of diffracting the transformed light
beams, it is noted that optionally, the plurality of light patterns
provided by the diffractive optical element are copies of a
predetermined light pattern. In other words, stage 540 may include
stage 541 of diffracting each of the transformed light beams to
provide a plurality of light patterns which are copies of a
predetermined light pattern. Optionally, stage 541 may include
diffracting each of the light patterns by the DOE to provide a copy
of the predetermined pattern.
[0363] While not necessary so, the copies of the predetermined
light pattern (if implemented) may be adjacent to each other. This
may be used for tiling an area whose size is much larger (e.g. at
least 50 times larger) than a size of any of the projected copies
of the predetermined light pattern. This way, a relatively simple
DOE (which is cheaper to design and to manufacture) which is
designed to diffract an incident coherent light beam to provide a
relatively simple light pattern--may be used to generate much
larger and more complex or intricate structured light pattern, e.g.
as demonstrated (in small scale, only 6 times larger) in FIG. 4A.
Stage 541 may include stage 542 of diffracting the transformed
light beams to provide a plurality of copies of a predetermined
light pattern which are adjacent to each other.
[0364] Optionally, generating of the plurality of copies of the
predetermined light pattern according to method 500 (e.g. using a
single DOE) facilitates projection of a high contrast and high
clarity overall output pattern of the optical system.
[0365] It is noted that stage 540 may include stage 543 of
diffracting the transformed light beams to provide light patterns
which partly overlap each other. The partly overlapping light
patterns may be copies of the predetermined light pattern (in which
case each provided copy of the predetermined light pattern partly
overlaps at least one other provided copy of the predetermined
light pattern), but this is not necessarily so. Each of the partly
overlapping light patterns may be diffracted from a light beam
arriving from a single emitter, but this is not necessarily so.
[0366] Optionally, if stage 543 is implemented, the predetermined
light pattern may include multiple copies of a repeated subpattern,
wherein in each provided copy of the predetermined light pattern at
least one subpattern overlaps a subpattern of at least one other
provided copy of the predetermined light pattern generated by light
originating from another light emitter. Further discussion is
provided with respect to FIG. 4C.
[0367] Optionally, stage 510 of emitting the plurality of light
beams may include stage 511 of controlling activation of different
subgroups of emitters at different times, thereby resulting in
providing of offset overall output patterns of the optical system
at different times. Optionally, the light patterns provided by
diffracting the light of each of the light emitters in each of the
subgroups may be copies of the predetermined light pattern, but
this is not necessarily so.
[0368] With respect to the emitting of stage 510, it is noted that
the emitting may be executed by an emitter array which is dense
with individual emitters of coherent light beams, thereby enabling
spatially efficient providing of a high energy structured light
pattern.
[0369] With respect to stage 510, optionally, the emitter array may
include a plurality of individual emitters arranged so as to form a
planar emission plane. That is, optionally, stage 510 of emitting
the plurality of light beams may include emitting the plurality of
light beams by an emitter array which include a plurality of
individual emitters arranged so as to form a planar emission plane.
Referring to the examples set forth with respect to the previous
drawings, such an emitter as discussed with respect to FIG. 13, and
all of the discussion which pertains to FIG. 13 is applicable to
such a variation of stage 510, mutatis mutandis.
[0370] Referring to method 500 as a whole, a combination of (a) the
optical subunit used in stage 520 and (b) the diffractive optical
element used in stage 540 is characterized by a distortion
function. Optionally, the emitter array used for the emitting of
stage 510 may include a plurality of individual emitters which are
arranged in a non-uniform configuration whose relation to a
predefined uniform grid is an inverse function of the distortion
function. That is, stage 510 may include emitting the plurality of
light beams by an emitter array which includes a plurality of
individual emitters which are arranged in a non-uniform
configuration whose relation to a predefined uniform grid is an
inverse function of the distortion function.
[0371] An example of the distortion function of optical subunit 220
is presented in FIGS. 12D and 12E. As can be seen, a regular grid
of individual emitters 212 in FIG. 12D is transformed into a
non-regular array of illumination. Method 900 in FIG. 25 discloses
a method which may be used to determine the distortion function,
and based on which to determine a non-uniformed configuration which
may be used for the individual emitters of system 205.
[0372] FIG. 19 is a flow chart illustrating an example of method
600, in accordance with examples of the presently disclosed subject
matter.
[0373] It is noted that method 600 may incorporate any of the
stages and variations discussed above with respect to method 500 as
general. Furthermore, method 600 may incorporate any of the stages
and variations discussed below with respect to method 700 and to
method 800. The stages of method 600 are denoted using the similar
numeral reference used for the stages of method 500, increased by
100 (e.g. stage 610 is comparable to stage 510, and so on), and the
variations discussed with respect to these stages in other parts of
the document may also pertain, mutatis mutandis, to method 600.
Referring to the examples set forth with respect to the previous
drawings, method 600 may be implemented by system 201.
[0374] Stage 610 of method 600 includes emitting a plurality of
light beams. Each of the plurality of light beams emitted in stage
610 is characterized by a native beam width.
[0375] Stage 620 includes transforming the plurality of light beams
so that each of the transformed light beams is characterized by an
expanded beam width that is wider than the native beam width of the
corresponding light beam and is wider than a facilitating beam
width. Referring to the examples set forth with respect to the
previous drawings, stage 620 may be implemented by optical subunit
220.
[0376] Stage 640 includes diffracting the transformed light beams
by a diffractive optical element (DOE) to provide light patterns
whose angular resolution meets a light pattern target angular
resolution criteria. Referring to the examples set forth with
respect to the previous drawings, stage 640 may be implemented by
DOE 230.
[0377] Referring to stage 610, optionally the emitting of stage 610
may include emitting the plurality of light beams whose native beam
widths are narrower than the facilitating beam width by at least
one order of magnitude.
[0378] FIG. 20 is a flow chart illustrating an example of method
600, in accordance with examples of the presently disclosed subject
matter. It is noted that not all of the stages which are
illustrated in FIG. 20 should necessarily be implemented together,
and that any combination of any of the optional stages may be
implemented.
[0379] Method 600 may include stage 630 of directing the
transformed light beams toward the DOE. Referring to the examples
set forth with respect to the previous drawings, stage 630 may be
implemented by optical subunit 220.
[0380] Stage 630 may include stage 631 of deflecting (by refraction
or otherwise) the plurality of light beams and projecting the
plurality of transformed light beams onto the diffractive optical
element at different angles of incidence. Referring to the examples
set forth with respect to the previous drawings, stage 630 may be
implemented by optical subunit 220.
[0381] Stage 640 which follows stage 630 (if implemented) includes
providing a plurality of light patterns by the diffractive optical
element, and providing a structured light pattern which includes
the plurality of light patterns.
[0382] Optionally, stage 620 may include reducing beam divergence
of the light beam. For example, if each light beam out of the
plurality of light beams is characterized by a first beam
divergence of that beam, stage 620 may include stage 621 of
transforming the plurality of light beams so that each of the
transformed light beams is characterized by a second beam
divergence that is smaller than the first beam divergence of the
corresponding light beam.
[0383] Optionally, stage 620 may include stage 621 of transforming
the plurality of light beams so that the expanded beam widths of
each of the plurality of transformed light beams is at least 3
times larger than the native beam width of the corresponding light
beams.
[0384] FIG. 21 is a flow chart illustrating an example of method
700, in accordance with examples of the presently disclosed subject
matter. It is noted that method 700 may incorporate any of the
stages and variations discussed above with respect to method 500 as
general. Furthermore, method 700 may incorporate any of the stages
and variations discussed below with respect to method 600 and to
method 800. The stages of method 700 are denoted using the similar
numeral reference used for the stages of method 500, increased by
100 (e.g. stage 710 is comparable to stage 510, and so on), and the
variations discussed with respect to these stages in other parts of
the document may also pertain, mutatis mutandis, to method 700.
Referring to the examples set forth with respect to the previous
drawings, method 700 may be implemented by system 202.
[0385] Stage 710 of method 700 includes emitting a plurality of
light beams. Each of the light beams emitted in stage 710 is
characterized by a first beam divergence of that beam. Referring to
the examples set forth with respect to the previous drawings, stage
710 may be implemented by emitter array 210.
[0386] Stage 720 of method 700 includes transforming the plurality
of light beams so that each of the transformed light beams is
characterized by a second beam divergence that is smaller than the
first beam divergence of the corresponding light beam. Referring to
the examples set forth with respect to the previous drawings, stage
720 may be implemented by optical subunit 220.
[0387] Optionally, the transforming may be executed by an optical
subunit which is an optical assembly including a plurality of
optical elements having a common optical axis common to the
plurality of optical elements.
[0388] Optionally, the transforming may be executed by an optical
subunit which is operable to transform the plurality of light beams
to provide the plurality of transformed light beams using
transforming optical components (included in the optical subunit)
which are common to the plurality of light beams.
[0389] Stage 740 of method 700 includes diffracting the transformed
light beams by a diffractive optical element (DOE) to provide light
patterns.
[0390] With respect to method 700, it is noted that a facilitating
beam divergence may be defined for the DOE (used in stage 740), so
that incidence upon the DOE of coherent light beams whose
divergence is lower than the facilitating beam divergence result in
provision of light patterns whose contrast meets a light pattern
target contrast criteria.
[0391] The transforming and the diffracting of the light beam in
method 700 may be implemented so that the second beam divergences
of the plurality of transformed light beams are lower than the
facilitating beam divergence.
[0392] FIG. 22 is a flow chart illustrating an example of method
700, in accordance with examples of the presently disclosed subject
matter. It is noted that not all of the stages which are
illustrated in FIG. 22 should necessarily be implemented together,
and that any combination of any of the optional stages may be
implemented.
[0393] Stage 710 may include stage 711 of emitting the plurality of
light beams so that the first beam divergence of any of the emitted
light beams is larger than the facilitating beam divergence by at
least one order of magnitude.
[0394] Method 700 may include stage 730 of directing the
transformed light beams toward the DOE. Referring to the examples
set forth with respect to the previous drawings, stage 730 may be
implemented by optical subunit 220. Referring to the examples set
forth with respect to the previous drawings, stage 730 may be
implemented by optical subunit 220.
[0395] Stage 730 may include stage 731 of deflecting (by refraction
or otherwise) the plurality of light beams and projecting the
plurality of transformed light beams onto the diffractive optical
element at different angles of incidence. Referring to the examples
set forth with respect to the previous drawings, stage 730 may be
implemented by optical subunit 220.
[0396] FIG. 23 is a flow chart illustrating an example of method
800, in accordance with examples of the presently disclosed subject
matter. It is noted that method 800 may incorporate any of the
stages and variations discussed above with respect to method 500 as
general. Furthermore, method 800 may incorporate any of the stages
and variations discussed below with respect to method 600 and to
method 700. The stages of method 800 are denoted using the similar
numeral reference used for the stages of method 500, increased by
100 (e.g. stage 810 is comparable to stage 510, and so on), and the
variations discussed with respect to these stages in other parts of
the document may also pertain, mutatis mutandis, to method 800.
Referring to the examples set forth with respect to the previous
drawings, method 800 may be implemented by system 203.
[0397] Stage 810 of method 800 includes emitting a plurality of
light beams. Referring to the examples set forth with respect to
the previous drawings, stage 810 may be implemented by emitter
array 210.
[0398] Stage 820 of method 800 includes transforming the plurality
of light beams. Stage 820 includes at least on of stages 821 of
expanding the plurality of light beams, and/or stage 822 of
collimating of the plurality of light beams. Referring to the
examples set forth with respect to the previous drawings, stage 820
may be implemented by optical subunit 220. As aforementioned with
respect to optical subunit 220, the optical subunit used for the
transforming may include a plurality of optical elements having a
common optical axis common to the plurality of optical elements.
The common optical axis may be folded once or more, but this is not
necessarily so.
[0399] Stage 830 of method 800 includes directing the plurality of
transformed light beams onto a diffractive optical element at
different angles of incidence. Referring to the examples set forth
with respect to the previous drawings, stage 830 may be implemented
by optical subunit 220. It is noted that the directing of stage 830
may be done by the same optical components used for executing stage
820 of transforming the plurality of light beams, or at least
partly by other optical components.
[0400] Stage 840 of method 800 includes diffracting the plurality
of transformed light beams by the diffractive optical element (DOE)
to provide a plurality of light patterns.
[0401] Stage 840 of emitting includes stage 841 of emitting the
plurality of light beams by a plurality of individual emitters
which are positioned so that for each of the individual emitters
there is at least one other individual emitter positioned at a
distance which is smaller than any beam width of any transformed
light beam out of the plurality of transformed light beams.
[0402] FIG. 24 is a flow chart illustrating an example of method
500, in accordance with examples of the presently disclosed subject
matter. It is noted that stages 550, 560, 570 and 580 discussed
below may be also included as part of methods 600, 700 and 800
(following stages 640, 740 and 840, respectively).
[0403] Method 500 may further include stage 550 of projecting onto
one or more objects at least a part of a structured light pattern
which includes the plurality of light patterns. Referring to the
examples set forth with respect to the previous drawings, the
projecting of stage 550 may be executed directly by the DOE (e.g.
DOE 230), or by dedicated projecting optics (such as projecting
optics 240).
[0404] Method 500 may further include stage 560 of capturing an
image of the object with the structured light pattern projected
thereon. Referring to the examples set forth with respect to the
previous drawings, stage 560 may be implemented by imaging sensing
unit 250.
[0405] Stage 560 may be followed by stage 570 of processing the
image to determine range parameters. Referring to the examples set
forth with respect to the previous drawings, stage 570 may be
implemented by processing unit 260.
[0406] Optionally, stage 570 may be followed by stage 580 of
generating a 3D image of a scene which includes at least part of
the object which is illuminated with the structured light pattern.
Referring to the examples set forth with respect to the previous
drawings, the description of FIG. 15 may be applied, mutatis
mutandis, to the process of stage 580.
[0407] FIG. 25 is a flow chart illustrating an example of method
900, in accordance with examples of the presently disclosed subject
matter. Method 900 may be used for determining an emitters layout.
It is noted that method 900 may be used to determine an emitters
layout for the emitter array of a system such as systems 200, 201,
202, 203, 204 and 205, and that any variation and optional
implementation which was discussed with respect to any one of
systems 200, 201, 202, 203, 204 and 205 may apply to the various
stages of method 900, mutatis mutandis, where applicable.
[0408] Stage 910 of method 900 includes obtaining optical
characteristics of a DOE positioned at a given distance from a
light source. Referring to the examples set forth with respect to
the previous drawings, the DOE may be DOE 230, and the light source
may be emitter array 210.
[0409] Various kinds of optical characteristics may be obtained in
various implementations of stage 910. Some examples of optical
characteristics which may be obtained in stage 910 are: diffraction
parameters of various areas on the DOE, size of the DOE, material
of the DOE, shape of the DOE, and so on.
[0410] The obtaining of stage 910 may be executed in various ways.
For example, stage 910 may include retrieving the optical
characteristics from a database. For example, stage 910 may include
retrieving the optical characteristics from a tangible data storage
medium (e.g. a compact disk, a hard-drive, a magnetic tape, a
random-access memory, and so on). For example, stage 910 may
include obtaining the optical characteristics by measuring and/or
otherwise examining the DOE. Other ways of obtaining the optical
characteristics may also be implemented.
[0411] Stage 920 of method 900 includes obtaining data in respect
of a provisional light beams emission layout through the DOE.
[0412] Various kinds of data in respect of a provisional light
beams emission layout may be obtained in various implementations of
stage 910. Some examples of data in respect of a provisional light
beams emission layout which may be obtained in stage 920 are:
distortion function of the DOE; distortion function of a
combination of the DOE and connected optics (e.g. optical subunit
220 of system 220); design of the DOE, ray tracing simulation of
light passing through the DOE, experimental result of light of the
light source propagation through the DOE, and so on.
[0413] The obtaining of stage 920 may be executed in various ways.
For example, stage 920 may include retrieving the data in respect
of a provisional light beams emission layout from a database. For
example, stage 920 may include retrieving the data in respect of a
provisional light beams emission layout from a tangible data
storage medium (e.g. a compact disk, a hard-drive, a magnetic tape,
a random-access memory, and so on). For example, stage 920 may
include obtaining the data in respect of a provisional light beams
emission layout by simulating light propagation through the DOE.
For example, stage 920 may include obtaining the data in respect of
a provisional light beams emission layout by emitting light from a
light source through the DOE and measuring light propagation
through the DOE. Other ways of obtaining the optical
characteristics may also be implemented.
[0414] Stage 930 of method 900 includes obtaining a target emission
layout. Referring to the examples set forth with respect to the
previous drawings, the target emission layout may be structured
light pattern 150. Referring to the examples set forth with respect
to the previous drawings, the target emission layout may be light
pattern 140.
[0415] The obtaining of stage 930 may be executed in various ways.
For example, stage 930 may include retrieving the target emission
layout from a database. For example, stage 930 may include
retrieving the target emission layout from a tangible data storage
medium (e.g. a compact disk, a hard-drive, a magnetic tape, a
random-access memory, and so on).
[0416] Stage 940 of method 900 includes determining an emitters
layout based on the target emission layout and based on the
provisional light beams emission layout. Referring to the examples
set forth with respect to the previous drawings, the emitters
layout determined in stage 940 may be an emitter layout according
to which individual emitters 212 of emitter array 210 are
arranged.
[0417] The determining of the emitters layout may include
determining a 2D emitters layout (e.g. if a planar emission plane
is used), and may also include determining a 3D emitters
layout.
[0418] Optionally, stage 940 may include determining the emitters
layout, such that light emitted by a light source positioned at the
given distance from the DOE and having a plurality of emitters
arranged according to the emitters layout is diffracted through the
DOE is characterized by a layout (e.g. structured light, also
referred below as the result structured light) that meets a target
emission criterion that is based on the target emission layout.
[0419] For example, the target emission criterion (which may be a
predefined criterion) may be that intensity differences between the
intensity of the result structured light and the target emission
layout at any point of the result structured light are below a
certain (e.g. predefined) threshold, such as a certain percentage
(say 90% or above. For example, the target emission criterion may
be that the average intensity differences between the intensity of
the result structured light and the target emission layout for the
entire result structured light is below a certain (e.g. predefined)
threshold, such as a certain percentage (say 90% or above).
[0420] While certain features of the invention have been
illustrated and described herein, many modifications,
substitutions, changes, and equivalents will now occur to those of
ordinary skill in the art. It is, therefore, to be understood that
the appended claims are intended to cover all such modifications
and changes