U.S. patent application number 11/123606 was filed with the patent office on 2005-10-27 for apparatus & methods for creating real-time 3-d images and constructing 3-d models of an object imaged in an optical system.
Invention is credited to Greenberg, Gary.
Application Number | 20050237606 11/123606 |
Document ID | / |
Family ID | 34549627 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050237606 |
Kind Code |
A1 |
Greenberg, Gary |
October 27, 2005 |
Apparatus & methods for creating real-time 3-D images and
constructing 3-D models of an object imaged in an optical
system
Abstract
Dynamic aperture microscopy in which the portion of an objective
aperture that passes light in an optical system that images an
object is continuously changed to create motion parallax which
continuously changes the angle from which the object is viewed to
create a moving 3-D view of the object from which a 3-D model of
the object can be constructed that can be seen or measured from any
angle.
Inventors: |
Greenberg, Gary; (Marina Del
Rey, CA) |
Correspondence
Address: |
H. Michael Brucker
Suite 110
5855 Doyle Street
Emeryville
CA
94608
US
|
Family ID: |
34549627 |
Appl. No.: |
11/123606 |
Filed: |
May 6, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11123606 |
May 6, 2005 |
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09552180 |
Apr 18, 2000 |
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6891671 |
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Current U.S.
Class: |
359/388 ;
359/368 |
Current CPC
Class: |
G02B 30/54 20200101;
G02B 21/0004 20130101; G02B 21/06 20130101 |
Class at
Publication: |
359/388 ;
359/368 |
International
Class: |
G02B 021/06 |
Claims
1-19. (canceled)
20. In an optical system having an objective aperture for viewing
an object the improvement comprising: a shaped light beam
continuously passing through a different portion of the objective
aperture.
21. The improvement of claim 13 wherein said shaped light beam is
from an array of LEDs.
22-38. (canceled)
39. In a method of creating a three dimensional model of a three
dimensional object using a light microscope having a focal plane
the steps comprising: viewing the object with the microscope focal
plane at various locations within the object; for each location of
the focal plane within the object, causing the angle of view to
continuously change.
40. The method of claim 39 wherein the object is composed of a
plurality of elements and further comprising the steps of: creating
a digitized image of the object at each location of the focal
plane; eliminating from each digitized image those elements that
change location with time to create a focal plane specific
image.
41. The method of claim 40 further comprising the step of:
combining the focal plane specific images.
42-51. (canceled)
Description
FIELD OF THE INVENTION
[0001] The present invention relates to optical systems, and more
particularly, to methods and apparatus for creating and capturing
perceivable 3-D images of an object and constructing 3-D models of
the object that can be viewed and measured from any angle.
BACKGROUND OF THE RELATED ART
[0002] Based on the state of the art prior to the present
invention, the creation of a viewable 3-D image of an object in an
optical system, such as a microscope, requires the use of filters,
dual imaging systems or expensive viewing optics, all of which have
their known disadvantages. The prior art has used the notion of
convergence parallax or stereoscopic viewing from two angles
simultaneously. In the present invention, we teach the use of
motion parallax to create a perceivable 3-D image.
[0003] Prior to the present invention, it has not been possible to
view an object in real-time 3-D through a standard microscope by
the addition of a relatively inexpensive add-on device or to create
a tomographic model of an object using such a device.
SUMMARY OF THE INVENTION
[0004] The present invention teaches methods and apparatus for
obtaining 3-D images of an object in a standard microscope by
continuously changing the angle from which the image of the object
is viewed. "View", "viewing" and "viewed" as used throughout this
specification refer to detection of an image by either the human
eye or an optical or electronic device or system.
[0005] A typical optical system for creating the image of an
object, such as a microscope, includes one or more aperture planes
conjugate to the objective lens aperture, such as the condenser
lens aperture, the light source of the system, the eye-point of the
eyepiece (or barlow lens) or any conjugate relayed aperture plane
that uses relay lenses. When used herein, "objective aperture"
refers to the objective lens aperture and any aperture at a plane
conjugate to the objective lens aperture.
[0006] The present invention teaches that by selecting an objective
aperture in either the illumination path or the viewing path of a
light transmitting optical system and continuously changing the
portion of that objective aperture through which the light passes,
motion parallax is created. To the viewer, the image of the object
is continuously moving in a way that makes the foreground elements
of the image distinguishable from the background elements. In this
way, the image appears to the viewer in 3-D without the need for
any viewing aids, such as special 3-D spectacles or filters. In
fact, with the present invention, 3-D perception is even created in
microscopes having only a monocular viewing head.
[0007] When the portion of the selected objective aperture that
passes light is continuously changed, as, for example, by rotating
an off-centered opaque mask having an aperture (mask aperture) at
an objective aperture, the image of the object will appear to move
in an inclined rotary motion, distinguishing the elements of the
image in the foreground from those in the background.
[0008] If the portion of the selected objective aperture that
passes light is continuously changed by a back and forth motion of
a mask aperture in the y-axis, then the image appears to rock back
and forth. If the back and forth motion is in the x-axis, then the
image will appear to roll from left to right.
[0009] The shape of the moving mask aperture will determine image
properties, such as depth of field, definition (highlighting and
shadowing effects), contrast, resolution and parallax angle
differences. The present invention provides for control of image
properties by selecting different shapes and sizes for dynamic mask
apertures. The dynamic mask apertures can be physical openings in
otherwise opaque members or other means of occluding light, such as
LCD shutter mechanisms, and can be inserted or removed from the
light path as required.
[0010] In addition to a dynamic mask aperture for continuously
changing the portion of a selected objective aperture that passes
light, the advantages of the present invention are also achieved by
continuously moving a shaped light beam at a selected objective
aperture so that the portion of the aperture which passes light is
continuously changed. A "shaped beam" as used herein means a light
beam that is shaped such that it fills less than the entire
objective aperture and as used herein includes, without limitation,
masked beams, focused beams and an array of light-emitting diodes
(LEDs). By locating an array of LEDs at an objective aperture (such
as a condenser lens aperture) and stimulating different ones of the
LEDs in a timed sequence, it is possible, using known techniques,
to continuously change the portion of the objective aperture that
passes light. In such a case, the LED array is both the shaped beam
and the light source.
[0011] Regardless of the particular motion generated or the
particular structures used to continuously change the portion of a
selected objective aperture that passes light, the continuously
moving image created distinguishes the relative positions of the
elements of the object and the object can be detected in 3-D by
continuously interrogating the object from different points of
view.
[0012] When the objective aperture is in the illumination part of
the system, the benefits of oblique illumination are also imparted
to the image.
[0013] Because the invention can be applied to an objective
aperture in either the illumination or viewing paths of an optical
system, the present invention is useful in systems using
transmitted illumination, reflection illumination or
florescence.
[0014] The present invention permits the creation of a series of
discrete, obliquely angled images at particular locations
throughout the object. Such a series of images can be digitized and
analyzed by a computer program that will create an accurate
three-dimensional model of the object that can be viewed and
measured from any angle. Thus, the invention, when combined with an
optical viewing system, constitutes the hardware portion of a
tomographic microscope.
[0015] It is an object of the present invention to create a 3-D
image of an object in an optical system without the use of viewing
aides, such as special spectacles or the like.
[0016] It is an object of the present invention to create a
viewable 3-D image of an object in an optical system by creating
motion parallax.
[0017] It is another object of the invention to create motion
parallax in an optical system for creating a 3-D image of an object
by continuously changing the portion of an objective aperture
through which light passes.
[0018] A further object of the present invention is to create a
series of images of an object that can be digitized and analyzed by
a computer program that will create an accurate three-dimensional
model of the object that can be viewed and measured from any
angle.
[0019] Other advantages and objects of the invention will be
apparent to those skilled in the art from the description of the
invention which follows with reference to the following
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a typical lens aperture;
[0021] FIG. 1a is a schematic side view illustration of a typical
condenser lens;
[0022] FIG. 2 is a mask of the present invention at the
aperture;
[0023] FIG. 2b is the lens of FIG. 1a with the mask of FIG. 2
disposed at the aperture;
[0024] FIG. 3 is another mask of the present invention at the lens
aperture;
[0025] FIG. 3a is the lens of FIG. 1a with the mask of FIG. 3
disposed at the aperture;
[0026] FIG. 4 is another mask of the present invention at the lens
aperture;
[0027] FIG. 4a is the lens of FIG. 1a with the mask of FIG. 4
disposed at the aperture;
[0028] FIG. 5 illustrates the mask of FIG. 4 at different phases of
its rotation;
[0029] FIG. 5a is an embodiment of a mask of the present invention
formed from an LED matrix;
[0030] FIG. 6 is a side view of a typical prior art microscope;
[0031] FIG. 7 is an embodiment of the present invention utilizing
an off-axis iris diaphragm;
[0032] FIG. 8 is a side view of a lens having a gear-driven dynamic
aperture mask of the present invention at its objective
aperture;
[0033] FIG. 8a is a plan view of the mask of the present invention
shown in FIG. 8;
[0034] FIG. 9 is a side view of an embodiment of the present
invention using a turret carrying multiple masks of the present
invention;
[0035] FIG. 9a is a plan view of the turret and masks of FIG.
9;
[0036] FIG. 9b is the same as FIG. 9a, except that the masks have a
different shape;
[0037] FIG. 10 is an embodiment of the present invention employing
a slider on which multiple masks of the present invention are
carried;
[0038] FIG. 11 is a side schematic view of an embodiment of the
present invention incorporated in a phototube eyepiece for use with
a camera;
[0039] FIG. 12 is a side schematic view of the present invention
embodied in a light source;
[0040] FIG. 12a is a plan view of the dynamic aperture mask of the
present invention of FIG. 12;
[0041] FIG. 13a is an illustration of the dynamic aperture mask of
the present invention relative to a low NA objective;
[0042] FIG. 13b is an illustration of the dynamic aperture mask of
the present invention relative to a medium NA objective;
[0043] FIG. 13c is an illustration of the dynamic aperture mask of
the present invention relative to a high NA objective;
[0044] FIG. 14a is an embodiment of a dynamic mask of the present
invention utilizing overlapping semi-circle opaque members;
[0045] FIG. 14b is a view of FIG. 14a with the members rotated to a
different relative position;
[0046] FIG. 15 is an illustration of the dynamic aperture mask of
the present invention in which the change in position of the light
passing through the aperture is linear;
[0047] FIG. 15a is a diagrammatic illustration of an image of an
object illustrated as shown in FIG. 15;
[0048] FIG. 16 is a side schematic illustration of an embodiment of
the present invention utilizing a motor-driven optical fiber light
source;
[0049] FIG. 17 is another side view schematic of another embodiment
of the present invention utilizing a fiber optic light source;
[0050] FIG. 18 is another side view schematic of the present
invention utilizing a fiber optic light source;
[0051] FIG. 19 is a schematic side view of an object viewed with
the present invention illustrating the movement of the elements of
the object as perceived through a microscope utilizing the present
invention;
[0052] FIG. 20 is a schematic illustration of the present invention
embodied in an endoscope;
[0053] FIG. 21 is an illustration of the present invention
utilizing overlapping sector-shaped blades;
[0054] FIG. 21a shows the blades of FIG. 21 extended to obscure a
greater portion of the aperture at which it is placed;
[0055] FIG. 22 is a schematic illustration of an embodiment of the
invention utilizing expanding bellows;
[0056] FIG. 23a is an illustration of the present invention
utilizing sector-shaped LCDs;
[0057] FIG. 23b is FIG. 23a with certain of the LCDs rendered
opaque;
[0058] FIG. 23c is yet another illustration of FIG. 23a with other
LCDs rendered opaque;
[0059] FIG. 24 is an illustration of the present invention
utilizing an array of LEDs.
DETAILED DESCRIPTION OF THE INVENTION
[0060] The invention resides in methods and apparatus for
continually changing the portion of an objective aperture in an
imaging optical system that passes light so that the object is
continually being viewed from a changing angle, permitting the
elements of the image of the object in the foreground to be
distinguishable from the elements of the image of the object in the
background. Several structural embodiments of the invention achieve
this result.
[0061] Referring to FIGS. 1 and 1a, a typical microscope condenser
lens 11 has an aperture 12 defining an area 13. A light beam 14
entering the condenser 11 passes through the aperture 12 and
emerges along the optical axis 16. There being no occlusion of the
aperture 12, its entire area 13 is typically filled with the light
beam 14.
[0062] Referring to FIGS. 2 and 2a, a mask 17 having an opaque
sector 18 and a sector-shaped mask aperture 18a which can pass
light is disposed at the lens aperture 12. A light beam 15 entering
the lens 11 passes through the mask aperture 18a (which is the
three-quarters of the lens aperture 12 not occluded by the sector
18) and emerges from the lens at an angle .O slashed. to the
optical axis 16. The beam 15 emerges from lens 11 as an oblique
beam (relative to the optical axis 16) and the angle .O slashed. is
a measure of the obliquity of the beam.
[0063] Referring to FIGS. 3 and 3a, a mask 19 having an opaque
sector 22 and a semi-circular mask aperture 22a which can pass
light is disposed at the lens aperture 12 occluding one-half of the
area of the aperture 12. A light beam 21 entering lens 11 passes
through the half of lens aperture 12 aligned with mask aperture 22a
and emerges from the lens 11 at an oblique angle .O slashed..
[0064] Referring to FIGS. 4 and 4a, a mask 23 having an opaque
sector 26 and a sector-shaped mask aperture 26a is disposed at lens
aperture 12, three-quarters of which it occludes. A light beam 24
entering lens 11 passes through only the mask aperture 26a and
emerges from the lens 11 at an angle .O slashed. to the optical
axis 16. As the opaque area of the mask increases (the mask
aperture area decreases), the beam angle .O slashed. increases.
Stated somewhat differently, as the area of the mask aperture
decreases, so does the cone angle of the beam that emerges from the
lens as measured at the focal plane 28 of the lens.
[0065] For each of the embodiments of FIGS. 2a-4a, an object 27 at
an image (focal) plane 28 is illuminated with oblique illumination,
and thus, ultimately viewed from an angle relative to the optical
axis 16.
[0066] When it is stated that a mask or other element is located
"at" an objective aperture, it shall mean, and will be understood
by those skilled in the art, that the mask or other element is at
that proximity to the objective aperture that an image of the mask
or other element does not appear at an image plane in the optical
system.
[0067] By rotating any of masks 17, 19 or 23, the portion of the
lens aperture 12 which passes light is continually changed. As the
mask rotates, beam 24, for example (FIG. 4a), will rotate about
optical axis 16 so that the view of the image of object 27 will be
from a continually changing angle, allowing the observer to
interrogate the object through 360 degrees. By way of contrast,
stereo 3-D viewing only allows the observer to view the object from
two angles--a left angle and a right angle.
[0068] As used herein, the term "dynamic aperture mask" means a
mask having an aperture which, when continuously moved relative to
the objective aperture at which it is located, causes the portion
of that objective aperture that passes light to change
continuously.
[0069] Referring also to FIG. 5, the rotation of mask 23 about
optical axis 16 constantly moves the mask aperture 26 relative to
the objective aperture 12 and continuously changes the portion of
objective aperture 12 that passes light.
[0070] When a dynamic aperture mask, such as mask 23, is located at
an objective aperture in an optical system illumination path, the
object will be illuminated with oblique illumination and viewed
from a continually changing angle as the mask rotates. When the
object is illuminated with oblique illumination in this way, the
image of the object will be enhanced in a manner taught by
Greenberg U.S. Pat. No. 5,345,333.
[0071] When a dynamic aperture mask, such as mask 23, is disposed
at an objective aperture in the optical system image path (i.e.,
after the object has been illuminated), the image of the object
will also be viewed from a continually changing angle, and thus
seen in 3-D, but will not have the enhanced effects of oblique
illumination.
[0072] While the embodiment of the invention described above
teaches the use of a dynamic aperture in the shape of a sector of a
circle with the vertex of the sector at the optical axis, the
invention is not so limited. The invention resides in continually
changing the portion of the objective aperture through which light
passes so that the angle from which the object is viewed is
continually changed. This is also accomplished by continuously
moving a shaped beam through different portions of the aperture. An
LED array at the aperture plane that is controlled (turned on or
off in a way that simulates a light source continuously moving
through a different portion of the objective aperture also serves
the purpose of the invention to achieve its objects.
[0073] Referring to FIG. 5a, an array 27 of light-emitting diodes
(LEDs) 28 is located at an objective aperture 29. The diodes 28 are
controlled by control (switching) system 31 to create light
patterns and sequences that continuously change the portion of the
objective aperture (condenser aperture) through which light is
emitted. The array 27 can be controlled to produce a sector-shaped
light pattern that rotates about the optical axis of the aperture
29 or any other beam that can be moved continuously to create
motion parallax.
[0074] Referring to FIG. 6, a typical optical system using Kohler
illumination for imaging an object is a microscope 41 having an
objective lens 42 with an objective lens aperture 43, and a
condenser lens 44 having an aperture 46 which is conjugate to the
objective lens aperture 43, and according to the definition used
here, an objective aperture. Other objective apertures occur in the
microscope at light sources 47 and 48, as well as at the eye-point
49 of phototube 50 and the eye-point 51 of eyepiece 55. Another
objective aperture 52 is located in the optical system through
relay lenses (not shown).
[0075] Placing a dynamic aperture mask, such as mask 23 (FIG. 4),
at any of the objective apertures 43, 46, 47, 48, 49, 51 or 52 of
the microscope 41 will create a viewable moving 3-D image of an
object 53 in the otherwise 2-D microscope 41.
[0076] Microscope 41 operates as a transmitted light microscope
when the object 53 is illuminated by light source 54. By placing
dynamic aperture 23 at object plane 46 or 48 (in the illumination
path), the object 53 is illuminated with oblique illumination that
continually changes its angle, whereby the angle from which the
image of the object 53 is viewed at eyepiece 55 is continually
changing, giving the image the appearance of moving in
three-dimensional space. Placing a dynamic aperture, such as mask
23 (FIG. 4), at any objective aperture 43, 49 or 51 (in the viewing
path) of microscope 41 will cause the image of the object 53 to be
perceived as moving through three-dimensional space and, thus,
appearing as 3-D, even though not illuminated by oblique
illumination.
[0077] It will be readily apparent to those skilled in the art that
by substituting a standard condenser with a condenser 44 having a
dynamic aperture mask, such as that shown in FIG. 4, at objective
aperture 46, a microscope capable of only generating and viewing a
two-dimensional image can be economically converted to a microscope
that can create and view an image in real-time 3-D without filters
or special glasses. The insertion of such a dynamic aperture at
objective aperture 52, or any of the other microscope objective
apertures, will likewise convert a microscope limited to 2-D into a
microscope capable of viewing an object in 3-D (even if the
microscope has only a monocular viewing system).
[0078] The benefits of the present invention can be realized
utilizing various configurations of parts creating dynamic mask
apertures of various geometric shapes and sizes. The particular
physical embodiment or size and shape selected for a mask and its
dynamic aperture will depend on a number of factors, including the
effect that is desired and the characteristics of the object under
examination. Thus, while particular shapes for a dynamic mask
aperture may be more advantageous than others in certain
circumstances, all shapes and sizes of dynamic apertures and all
physical embodiments that create motion parallax and a 3-D image
are within the teachings of the invention. Similarly, which of the
several objective apertures in an optical imaging system where a
mask (dynamic aperture) of the present invention is located is a
matter of choice dependant on the circumstances of the
investigation.
[0079] For example, placing the dynamic aperture at the condenser
lens aperture is good for transmitting light applications, while
placing it in the illumination system is good for both transmitted
and reflected light applications. Placement at the illumination
system has the added advantage of allowing for special optical
systems, such as phase contrast optics. Additionally, placing the
dynamic aperture at the photo eyepiece makes it compatible with
florescence microscope.
[0080] Referring to FIG. 7, in one embodiment of the invention, a
standard iris diaphragm 58 having an opening 59 which is variable
in size, as indicated by dashed lined 61, is held within a circular
frame 62 by springs 63 and 64 and positioning screws 66 and 67. The
location of the iris opening 59 within the frame 62 is controlled
by screws 66 and 67. When the frame-held iris 58 is positioned to
locate the opening 59 off the center of an objective aperture 68,
rotation of the frame 62, together with the diaphragm iris 58,
causes the opening 59 to rotate within the aperture 68 and
continuously change the portion of the aperture 68 that passes
light. Frame 62 can be rotated by any one of several well known
drive systems, including friction, belt, or gear drive.
[0081] Referring to FIGS. 8 and 8a, a lens 71 has a dynamic
aperture mask 72 with a sector-shaped aperture 73 located at the
lens objective aperture 70. Gear teeth 74 on the periphery of the
dynamic aperture mask 72 mesh with a gear 76, which is rotated by a
shaft 77, which is connected to a motor 78 or other means for
rotating the shaft. As the gear 76 drives the dynamic aperture mask
74, the mask aperture 73 continuously changes the portion of the
objective aperture 70 that passes light, thus producing the motion
parallax which produces a 3-D effect.
[0082] Referring to FIGS. 9 and 9a, instead of locating a single
dynamic aperture mask, such as mask 72 (FIG. 8), at the objective
aperture of a lens, in this embodiment of the invention, a rotating
turret 81 is disposed in the plane of the objective aperture 80 of
a lens 82. The turret 81 carries four different dynamic aperture
masks 83, 84, 86 and 87, each having an aperture 83a, 84a, 86a and
87a, respectively, of a different geometric shape. The particular
shapes illustrated are only by way of example of the possible
shapes for mask apertures that are within the scope of the
invention. A standard iris diaphragm 88 can also be provided on the
turret 81 for standard operation of the lens.
[0083] A drive gear 89, driven by a gear motor and shaft 91,
engages the perimeter 92 of turret 81, enabling the turret 81 to be
rotated about its axis 93. The drive gear 89 can thus position the
turret 81 to align any of the masks 82, 84, 86, 87 or iris 88 with
the aperture 80 of lens 82, as desired. Positioning turret 81 by
hand is, of course, also an option. The alignment of a dynamic
aperture mask with the objective aperture 80 of lens 82 also aligns
the aperture mask with an aperture mask drive gear 94 for rotating
the aligned mask. This embodiment permits the easy selection of one
of a variety of different dynamic aperture masks for use as the
need arises. The shape of each dynamic aperture can be designed for
specific applications, such as phase contrast microscopy. Referring
to FIG. 9b, a mask 95 on turret carrier 81 has an aperture 95a in
the shape of a portion of a phase annulus. By rotating the phase
annulus aperture 95a, 3-D phase contrast effects are achieved. The
other masks illustrated provide apertures for use with different NA
lenses and different shaped annuli.
[0084] Referring to FIG. 10, in another embodiment of the
invention, a slide carrier 96 carries three rotatable dynamic
aperture masks 97, 98 and 99, each having an aperture 97a, 98a and
99a, respectively, of a different geometric shape and each rotated
by a belt 101 driven by a gear 102. Once again, the particular
shapes illustrated are only a sample of the many different shapes
that could be used. When the slide 96 is moved relative to a lens
aperture (such as objective aperture 80 of FIG. 9), one of the
dynamic aperture masks 97, 98 or 99 can be brought into alignment
with the objective aperture and the optical axis of the optical
system. Rotation of the mask will continuously change the portion
of the objective aperture through which light passes, and thus
produce the motion parallax which produces the 3-D effect of the
present invention. A conventional iris diaphragm 103 can be
conveniently located on the carrier 96, as well, for conventional
use of the optical imaging system with which the carrier 96 is
used.
[0085] Referring to FIG. 11, the present invention is embodied in
an adapter for a microscope phototube. An adapter 106 contains a
photo eyepiece 107 exclusively used to focus a light beam at an
eye-point 108, which is coincident with an objective aperture 109.
Light beam 105 carries an image of an object (not shown) that is
"seen" at an image plane 111 in a camera 112 that is supported on
the adapter 106 by a camera connector 113. Camera 112 can be a
digital camera, a video camera or any other device capable of
recording images.
[0086] A dynamic aperture mask 114 is located at the objective
aperture 109 and rotated by a gear 116, supported on a shaft 117,
driven by a motor 118. Dynamic aperture mask 114 can include an
aperture of any desired shape, such as those illustrated in FIGS.
9a and 10, so long as when the aperture mask 114 is rotated by gear
116, the portion of the aperture 109 that passes light is
continually changed whereby the image "seen" at image plane 111 of
camera 112 is from a continuously changing angle.
[0087] By replacing a standard phototube with the phototube 106 of
the present invention, a microscope capable of only creating and
capturing a 2-D image can be easily converted into a microscope
that can capture a 3-D image. One of the advantages of this
embodiment of the invention is that it is compatible with all forms
of microscopy, such as phase contrast, differential interference
contrast, florescence, transmitted or reflected light
microscopy.
[0088] Another embodiment of the present invention that
conveniently and economically converts a 2-D microscope into a 3-D
microscope is seen in FIGS. 12 and 12a. A lamp housing 121 having a
dovetail mounting connector 122 that permits it to attach to a
standard microscope lamp housing contains a lamp light source 123
and a lamp condenser lens 124. The light source 123 directs a light
beam 125 onto a diffusing filter 126 from which the light beam is
directed onto lamp condenser lens 124, and from there, into the
optical path of a microscope (not shown).
[0089] The lamp condenser lens 124 creates an objective aperture
127, at which is located a dynamic aperture mask 128 having a
sector-shaped aperture 129 which sweeps through the objective
aperture 127 when driven by a gear 131 mounted on a shaft 132
rotated by a motor 133. Once again, as the mask aperture 129
rotates, the portion of the objective aperture 127 that passes
light beam 125 is continually changed so that an object illuminated
by the light beam 125 in a microscope optical system will be
continuously illuminated from a changing angle and thus be
perceived in 3-D by virtue of the motion parallax created by light
beam 125. An advantage of this embodiment of the invention is that
it works with phase contrast optics by continuously illuminating a
different portion of a standard phase contrast annulus, regardless
of the size of the phase annuli.
[0090] Referring to FIGS. 13a, 13b and 13c, one of the advantages
of the embodiment of the present invention that utilizes a
sector-shaped aperture 136 in an aperture mask 137 is that it
operates equally with an objective of low numerical aperture (NA),
as well as an objective with a high NA.
[0091] Thus, while the mask 137 is substantially larger than the
low NA objective 138, rotation of the mask 137 nonetheless
continuously changes the portion of objective 138 through which
light can pass. Although the mask 137 stays the same in size, its
ability to produce effective motion parallax by rotating at the
mask aperture 136 of a medium NA objective 139 (FIG. 13b) or a high
NA objective 141 (FIG. 13c) remains the same. Thus, in terms of
what an objective aperture "sees," mask 137 is properly sized for a
wide range of NA lenses. One shape fits many different size
objective lenses with equal effect.
[0092] Referring to FIGS. 14a and 14b, another embodiment of the
invention provides a rotatable dynamic aperture mask where the
aperture is a sector of a circle which is variable in size. A
dynamic aperture mask 144 includes a support ring 146 containing
two semi-circular opaque aperture-forming members 147 and 148 which
are rotatable within ring 146 about a center point 149. By
overlapping a portion of the members 147 and 148, an aperture 151
is created which can pass light. Gears 152 on the outer
circumference of the ring 146 mesh with a drive gear 153 for
rotating the entire dynamic aperture mask 144. The size of aperture
151 is varied by rotation of the opaque members 147 and 148
relative to one another until the size of the aperture 151 best
suits the needs of the investigation being conducted. As the
aperture 151 increases in size, the illumination or viewing
affected by the dynamic aperture decreases in apparent movement and
vice versa. As the aperture 151 is decreased in size, the contrast
and depth of field is increased.
[0093] A number of other mechanical and electromechanical devices
are capable of creating a variable-size aperture in a dynamic mask,
such as mask 144. Details of such other mask configurations are set
forth in my copending application Ser. No. 09/715,636, for Methods
& Apparatus For Creating Real-Time 3-D Images, filed Nov. 27,
2000. In particular, instead of overlapping opaque semi-circular
members 147 and 148, the space within ring 146 could contain
overlapping blade structures, such as shown in FIGS. 21 and 21a,
which can be adjusted to create a variable-size aperture 151.
Referring to FIG. 22, a bellow-type expandable opaque mask 150 can
also create a variable size aperture 151. Similarly, liquid crystal
diodes (LCDs), such as shown in FIGS. 23a, 23b and 23c, can be used
to create a variable light-passing aperture 151 within ring 146.
FIG. 23a illustrates a circle formed by eight equal sector-shaped
LCDs 154, all conditioned to pass light. In FIG. 23b, two adjacent
LCDs 154 have been conditioned to be opaque to light so that the
remaining LCDs form a sector-shaped aperture that passes light.
FIG. 23c illustrates the LCDs 154 conditioned such that only two
adjacent sectors pass light to create an aperture 151 different in
shape than that of. FIG. 23b. The particular variable-shaped
rotatable aperture mask 144 illustrated in FIGS. 23a, 23b and 23c
is but an example of the shapes that can be formed using LCDs. The
advantage to using LCDs is that any shape can be achieved and
quickly changed to any other shape, including shapes that would be
difficult, if not impossible, to achieve with physical masks. In
addition, the shapes and their transitions can be computer-created
and controlled to create dynamic apertures tailored to specific
needs. In addition to sector-shaped LCDs, a mask can be formed from
an X-Y array of LCDs that can be switched to create any shape
desired that can be moved continuously so that light can be caused
to continuously move through a different portion of an objective
aperture. See Kley U.S. Pat. No. 4,561,731.
[0094] Thus, in addition to the plurality of different-size
apertures in a dynamic aperture mask, such as illustrated in FIGS.
9a and 10, the invention can also be embodied in a single mask
having a variable-size aperture.
[0095] All of the embodiments of the invention disclosed so far
include a rotating mask aperture at an objective aperture to
continually change the portion of the objective aperture which
passes light in order to create motion parallax and a 3-D view. The
objects of the invention are achieved, however, by different forms
of a dynamic aperture, as well as by a shaped beam in place of an
aperture mask.
[0096] Referring to FIGS. 15 and 15a by moving a shaped light beam
or an occluding mask back and forth across an objective aperture
156, the portion of the aperture which passes light is continually
changed, as best seen by the progressive change in the portion of
aperture 156 which passes light. As the light beam or occluding
mask swings across the aperture 156 to one extreme of its travel
light is passes through portion 156a of aperture 156. As it
retreats from that extreme light passes through portion 156b until
the entire aperture is filled with light when the beam is centered.
As the beam is moved beyond center the portion 156d passes light
and when the beam reached the extreme position in the other direct
portion 156e passes light. As the beam swings back, the pattern is
reversed. By occluding the aperture in this way, or by passing a
shaped light beam over the aperture 156, each element 157 of an
object being viewed (not shown) appears to rock back and forth, as
indicated by motion arrows 158. The combined effect of the rocking
motion of the elements of an object through the methods and
apparatus of the present invention reveals the three-dimensional
structure of the object similar to the three-dimensional view
created by the rotating dynamic aperture mask described above.
[0097] One of the advantages in using a rotating sector of a circle
or other geometric shape rotating about the center of the objective
aperture to continually change the portion of the aperture which
passes light is that the intensity of the light passed by the
aperture remains constant, whereas in the embodiment of FIGS. 15
and 15a, the light intensity varies considerably. This darkening
and lightening effect can be overcome or ameliorated by a feedback
system that continually changes the intensity of the light source
to effect an evenly illuminated image.
[0098] Referring to FIG. 16, one way to achieve the variable
occlusion of the objective aperture shown in FIG. 15 is by causing
a fiber optic bundle 161 illuminated by a light source 160 to
reciprocate relative to a lens 162 and its objective aperture 163.
A reciprocating motor 164 and connecting link 166 cause the fiber
optic bundle 161 to move back and forth a distance sufficient to
move a light beam 167 from the fiber optic bundle 161 across the
lens 162 so that, except when the fiber optic bundle is centered,
some portion of the objective aperture 163 is not illuminated by
the light beam 167, as illustrated in FIG. 15. The numbers 156a,
156c and 156e indicate the positions of bundle 161 that create the
aperture portions that pass light of the same numerical
designations in FIG. 15.
[0099] Referring to FIG. 17, a fiber optic bundle 169 receiving
light from a light source 171 produces a beam 172 having a
cross-section substantially smaller than the objective aperture 173
of a lens 174 onto which the beam is directed. A motor 176
connected to the fiber optic bundle 169 by a link 177 causes the
fiber optic bundle to move in a circle, as indicated by motion
arrow 178. As beam 172 rotates, the portion of aperture 173 that
contains light continually changes, producing substantially the
same effect as described in connection with the dynamic aperture
mask embodiment of the invention. (See particularly FIG. 7.) As
with a dynamic mask, motion parallax is created, giving rise to a
3-D effect. In the shaped light beam embodiment of the invention,
the intensity of the light that passes through the aperture 173 is
essentially constant.
[0100] Referring to FIG. 18, a light source 181 directs a beam of
light 182 onto a mirror 183, which reflects the light beam onto a
lens 184 through the objective aperture 186. A motor 187 connected
to mirror 183 through a link 188 causes mirror 183 to move in such
a way as to sweep beam 182 across the aperture 186 so as to create
the variable occlusion illustrated in FIG. 15.
[0101] Another way of creating a shaped light beam is to use an
array of light emitting diodes (LEDs) at an objective aperture.
Referring to FIG. 24, an array 179 of LEDs 180 can be controlled to
emit light in any pattern desired. Moreover, the selected shape can
be caused to move so that when placed at an objective aperture,
light will pass through a different portion of the aperture on a
continuous basis. The dark shaded diodes 179 form a sector 179a and
represent diodes that are emitting light. That sector can be caused
to rotate, creating the same result as the dynamic aperture mask of
FIG. 4, for example.
[0102] One application of the present invention is to create a
series of discrete obliquely angled images of an object at selected
planes throughout the object. The series of images so created can
be digitized and analyzed by a computer program to create a very
accurate three-dimensional model of the object that can be viewed
and measured from any angle. Thus, the present invention can be
combined with an ordinary microscope to create the hardware portion
of a tomographic microscope.
[0103] Referring to FIG. 19, an object 191 consists of a plurality
of object-forming elements 191a, 191b, 191c, 191d, 191e, 191f, 191g
and 191x. The object 191 is being imaged by an optical imaging
system, such as a microscope, having an optical axis parallel to
axes 193 and a focal plane at 194 within the object 191. When the
object 191 is viewed in an optical viewing system that includes an
objective aperture through which a light beam continuously passes
through a different portion, as taught by the present invention,
the various elements of object 191, other than those which are at
the image plane 194, precess about optical axis 193 in circles that
increase in diameter as the distance of the element from the image
plane 194 increases. Thus, for example, element 191a will move in a
larger circle about axis 193 than element 191b, which is closer to
the image plane 194. Element 191c, which is at the image plane,
will not move at all, whereas element 191d, which is about the same
distance from the image plane 194 as element 191b, will circle the
optical axis 193 in a circle of about the same diameter as the
circle traveled by element 191b, but be in an opposite phase
thereto. Each element of the object 191 that is off the optical
axis 194, such as elements 191f and 191x, will precess about an
axis 193. The combined effect of the apparent movement of the
various elements of the object 191, as seen in an optical system
employing the present invention, is that the entire object 191
appears to move in three-dimensional space so as to make it
possible to discern those elements of the object which are in the
foreground from those which are in the background and thus appear
in 3-D.
[0104] Because all of the elements of the object 191 that are off
of the image plane 194 move with time, it is possible, using known
digitizing and computer programming techniques, to eliminate from
an image of object 191 all of the elements, other than those that
appear at the image plane, by eliminating all elements that change
location with time. In this way, it becomes possible to create an
image of the object at a selected plane in the object, such as
plane 194. By moving the image plane to various locations within
object 191 (by, for example, refocusing the microscope), it becomes
possible to create a series of focal plane specific images of
object 191, and from that series of images, create an accurate
model of the object 191 that can be viewed and measured from any
angle.
[0105] Referring to FIG. 20, the dynamic aperture system of the
present invention can be used advantageously with imaging
techniques, such as endoscopy.
[0106] As is typical in endoscopy, a slender fiber optic tube 201
is inserted into a body 202 for the purpose of viewing interior
portions of the body 202 through a lens 203 in the distal end of
the fiber optic tube 201. The images created by the lens 203 are
directed to a camera 204 where they are recorded or displayed in
real-time by a monitor 206. One of the difficulties in dealing with
endoscopic images is that they lack three-dimensional perspective
making it difficult to determine the spacial relationship of the
various images being viewed.
[0107] The present invention provides a means for giving
three-dimensional perspective to the endoscopic images. A lens 207
between the camera 204 and the endoscopic tube 201 creates an
objective aperture 208 outside of the body 202 where it is
convenient to locate a dynamic aperture mask 209 of the present
invention which can be driven by a motor 211, as previously
described.
[0108] It will be obvious to those skilled in the art that the
dynamic aperture 209 can be any of the various embodiments of the
invention described therein, as well as those which are equivalent
thereto, and will not depart from the invention. In an endoscope,
as in any imaging system that has or is capable of having an
objective aperture, the present invention provides a means for
creating motion parallax from otherwise two-dimensional images so
as to create a three-dimensional perspective.
[0109] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It will,
therefore, be understood by those skilled in the art that within
the scope of the appended claims, the invention may be practiced
otherwise than as specifically described.
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