U.S. patent application number 15/151328 was filed with the patent office on 2017-11-16 for illumination system with active element for generating different illumination patterns for a data reader.
The applicant listed for this patent is Datalogic IP Tech, S.r.l.. Invention is credited to Michele Suman.
Application Number | 20170330008 15/151328 |
Document ID | / |
Family ID | 60189485 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170330008 |
Kind Code |
A1 |
Suman; Michele |
November 16, 2017 |
ILLUMINATION SYSTEM WITH ACTIVE ELEMENT FOR GENERATING DIFFERENT
ILLUMINATION PATTERNS FOR A DATA READER
Abstract
A data reader for reading and decoding a code from an item. The
data reader includes an imager operable to form an image of the
code from an item located in a field of view of the data reader.
The data reader further includes an illumination system including
optics arranged to direct light from one or more illumination
sources along one of a variety of different optical paths to
illuminate the field of view of the data reader with one of a
plurality of light patterns. The data reader also includes an
active element controllable to selectively direct the light along
one of the optical paths.
Inventors: |
Suman; Michele; (Padua,
IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Datalogic IP Tech, S.r.l. |
Lippo di Calderara |
|
IT |
|
|
Family ID: |
60189485 |
Appl. No.: |
15/151328 |
Filed: |
May 10, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06K 19/06037 20130101;
G06K 7/10732 20130101; G06K 7/10881 20130101 |
International
Class: |
G06K 7/10 20060101
G06K007/10; G06K 19/06 20060101 G06K019/06; G06K 7/10 20060101
G06K007/10 |
Claims
1. A data reader for reading data from items, the data reader
comprising: a housing; an imager carried within the housing, the
imager operable to form an image of a decodable code from an item
located in a field of view of the data reader; and an illumination
system carried within the housing, the illumination system
comprising: one or more illumination sources operable for emanating
light; and an optics system arranged to direct the light emanating
from the one or more illumination sources outwardly of the housing
to illuminate the field of view of the data reader, the optics
system comprising: a first mirror and a second mirror, the first
mirror arranged to direct the light emanating from at least one of
the one or more illumination sources toward the second mirror along
a first optical path, wherein the second mirror redirects the light
outwardly of the housing to illuminate the field of view with a
first light pattern; a window operable to allow at least a first
portion of the light emanating from at least one of the one or more
illumination sources to pass through the window and toward the
field of view; a wall having a reflective surface, the reflective
surface receiving at least a second portion of the light emanating
from at least one of the one or more illumination sources and
reflecting the light along a second optical path and through the
window to illuminate the field of view with a second light pattern;
and an active element controllable to selectively direct the light
emanating from at least one of the one or more illumination sources
along the first optical path associated with the first light
pattern and along the second optical path associated with the
second light pattern.
2. The data reader of claim 1, wherein the first mirror includes
one or more apertures extending therethrough, and wherein the
active element is further controllable to selectively direct the
light through the one or more apertures along the second optical
path to illuminate the field of view with the second light
pattern.
3. The data reader of claim 2, wherein the active element is a
liquid lens.
4. The data reader of claim 1, wherein the wall further includes
diffusive properties to diffuse the light emanating from the
illumination sources toward the window, and wherein the window is a
diffusive window operable to diffuse at least a third portion of
the light emanating from the illumination sources toward a portion
of the wall.
5. The data reader of claim 1, further comprising a third mirror
and an exit window adjacent the third mirror, wherein the second
mirror is arranged to direct the light toward the third mirror, and
wherein the third mirror is arranged to direct the light toward the
exit window to illuminate the field of view with the first light
pattern.
6. The data reader of claim 5, wherein the first and second mirrors
are stationary and the third mirror is movable to adjust the first
optical path of the light.
7. The data reader of claim 1, wherein the one or more illumination
sources are operable to generate light of a first wavelength and
light of a second wavelength, and wherein the first mirror includes
wavelength selective reflective optics to reflect light of the
first wavelength toward the second mirror along the first optical
path, the illumination system further comprising a third mirror
arranged in substantial alignment with the first mirror, the third
mirror including wavelength selective reflective optics to reflect
light of the second wavelength toward the reflective wall along the
second optical path.
8. The data reader of claim 7, wherein the one or more illumination
systems are further operable to generate light of a third
wavelength, the illumination system further comprising a lens
element in substantial alignment with the first and third mirrors,
the lens element directing the light of the third wavelength toward
the window along a third optical path to illuminate the field of
view with the third light pattern of the data reader.
9. The data reader of claim 8, wherein the window further includes
one or more apertures extending therethrough, wherein the light
traveling along the third optical path passes through the apertures
to illuminate the field of view with the third light pattern.
10. The data reader of claim 8, wherein the active element is a
controller in communication with the one or more illumination
sources, the controller operable to control a wavelength of the
light emanating from the one or more illumination sources to
selectively control which of the first, second, or third light
patterns illuminates the field of view.
11. The data reader of claim 7, wherein the active element is
operable to drive the one or more illumination systems to generate
light of both the first and second wavelengths concurrently to
simultaneously illuminate the field of view with both the first and
second light patterns.
12. The data reader of claim 1, wherein the first mirror is movable
along an axis between a first position and a second position,
wherein when the first mirror is in the first position, the first
mirror directs the light emanating from the one or more
illumination sources toward the second mirror along the first
optical path, and wherein when the first mirror is in the second
position, the first mirror directs the light emanating from the one
or more illumination sources toward the wall along the second
optical path.
13. The data reader of claim 12, wherein the active element is a
driver mechanism in communication with the first mirror and
selectively operable to move the first mirror along the axis
between the first and second positions.
14. The data reader of claim 1, further comprising a decoder for
decoding at least a portion of the decodable code.
15. A data reader for reading data from items, the data reader
comprising: a housing; an imager carried within the housing, the
imager operable to form an image of a decodable code from an item
located in a field of view of the data reader; and an illumination
system carried within the housing, the illumination system
comprising: a plurality of illumination sources operable for
emanating light; and an optics system arranged to direct light from
the one or more illumination sources outwardly of the housing to
illuminate the field of view of the data reader, the optics system
comprising: a first mirror arranged to direct light emanating from
a first illumination source of the plurality of illumination
sources toward an exit window along a first optical path, the light
passing through the exit window to illuminate the field of view
with a first light pattern; a lens element arranged to direct light
emanating from a second illumination source of the plurality of
illumination sources toward a window along a second optical path,
the light passing through the window to illuminate the field of
view with a second light pattern; a wall having a reflective
surface, the reflective surface receiving at least a portion of
light emanating from a third illumination source of the plurality
of illumination sources and reflecting the light along a third
optical path and through the window to illuminate the field of view
with a third light pattern; and an active element controllable to
selectively operate the plurality of illumination sources.
16. The data reader of claim 15, the window further including
apertures extending therethrough, wherein the lens element is
arranged to direct light through the apertures.
17. The data reader of claim 15, wherein the first, second, and
third illumination sources are operable to generate light of
different wavelengths.
18. The data reader of claim 15, wherein the first mirror is
movable to adjust the first optical path and the first light
pattern of the data reader.
19. A method of data reading, comprising: activating one or more
illumination sources carried within a housing of the data reader to
emanate light therefrom; selectively directing, via an active
element, the light from the one or more illumination sources along
a first optical path associated with a first light pattern or along
a second optical path associated with a second light pattern; for
the first optical path: directing a first light portion from the
one or more illumination sources toward a first mirror; redirecting
the light from the first mirror toward a second mirror along a
first optical path; and redirecting the light from the second
mirror outwardly of the housing to illuminate a field of view of
the data reader with a first light pattern; for the second optical
path: directing a second light portion from the one or more
illumination sources toward a window, wherein a first portion of
the second light portion passes through the window and toward the
field of view; redirecting, via the window, a second portion of the
second light portion toward a wall having diffusive and reflective
optical properties; reflecting, via the wall, the second portion of
the second light portion back toward the window along a second
optical path, wherein the second portion of the second light
portion passes through the window to illuminate the field of view
of the data reader with a second light pattern; and forming an
image of a decodable code from an item located in the field of view
of the data reader, wherein the field of view of the data reader is
illuminated with one or both of the first and second light
patterns.
Description
Background
[0001] The field of the present disclosure relates generally to
systems and methods for reading optical data, and in particular, to
such systems and methods capable of generating different
illumination patterns for improved data reading processes.
[0002] Optical codes, such as barcodes and other machine-readable
indicia, appear in a variety of applications. For example, optical
codes can be used to identify a class of objects (e.g.,
merchandise) or unique items (e.g., patents). As a result, optical
codes are found on a wide variety of objects, such as retail goods,
company assets, and documents. Typically, the optical codes are
placed on items and read as the items arrive or as they are sold to
help track production at manufacturing facilities or inventory at
stores. Optical codes come in a variety of forms, such as: linear
barcodes (e.g., UPC code), 2D codes including stacked barcodes
(e.g., PDF-417 code), and matrix codes (e.g., Datamatrix code, QR
code, or Maxicode). Typically, in a grocery or retail
establishment, such optical codes are often printed on tags or
stickers affixed to the item and/or printed directly on the item
packaging.
[0003] However, for many applications, it may be challenging to use
printed tags or labels, such as for items that need to pass through
harsh testing processing (e.g., chemicals, agents, thermal cycles,
oil, moisture, etc.), or items that need continuous tracking for
extended periods of time (e.g., the product lifecycle), or for
small items that are difficult to label. In these cases, a printed
label may be lost, damaged, or otherwise altered, thereby
detrimentally affecting the label reading and decoding process.
[0004] To address these challenges, a marking technique known as
direct part marking (DPM) has been developed to permanently
imprint, etch, mold, or otherwise directly mark an item, product,
or component with a machine-readable code, such as Data Matrix, QR
codes, other high-density codes, or one-dimensional optical codes.
Typically, a DPM code is comprised of multiple elements that are
directly marked on an exterior surface of an item, such as a metal,
wood, or plastic item. The optical codes may be captured and
processed from the marked product using an imaging data reader.
[0005] Despite the ability to precisely control the marking
process, one challenge with DPM technology is that DPM codes are
often difficult to read because the surfaces and/or textures on
which the DPM codes are marked may present reflectivity issues
and/or provide low and inconsistent contrast. Accordingly, DPM data
readers typically have a multi-faceted illumination system capable
of providing sufficient illumination for handling DPM codes on a
variety of surfaces, while minimizing specular reflection or other
issues. The present inventors have identified a need for an
improved and streamlined illumination system capable of providing
proper illumination to allow a data reader to read DPM codes.
Additional aspects and advantages of such data reading systems will
be apparent from the following detailed description of example
embodiments, which proceed with reference to the accompanying
drawings.
[0006] Understanding that the drawings depict only certain
embodiments and are not, therefore, to be considered limiting in
nature, these embodiments will be described and explained with
additional specificity and detail with reference to the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 schematically illustrates a handheld data reader for
reading an optical code marked on an itemsurface in accordance with
one embodiment.
[0008] FIGS. 2-4 illustrate an example embodiment of an
illumination system of the data reader of FIG. 1, the illumination
system including a lens for controlling the optical path of the
illumination and creating different light patterns.
[0009] FIGS. 5-8 illustrate another example embodiment of the
illumination system of the data reader of FIG. 1, the illumination
system including an arrangement of multi-colored illumination
sources for creating different light patterns.
[0010] FIGS. 9-11 illustrate another example embodiment of the
illumination system of the data reader of FIG. 1, the illumination
system including a movable mirror for controlling the optical path
of the illumination and creating different light patterns.
[0011] FIGS. 12-13 illustrate another example embodiment of the
illumination system using another arrangement of multiple-color
illumination sources to create different light patterns.
DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS
[0012] With reference to the drawings, this section describes
particular embodiments and their detailed construction and
operation. The embodiments described herein are set forth by way of
illustration only and not limitation. The described features,
structures, characteristics, and methods of operation may be
combined in any suitable manner in one or more embodiments. In view
of the disclosure herein, those skilled in the art will recognize
that the various embodiments can be practiced without one or more
of the specific details or with other methods, components,
materials, or the like. In other instances, well-known structures,
materials, or methods of operation are not shown or not described
in detail to avoid obscuring more pertinent aspects of the
embodiments.
[0013] FIG. 1 is a diagrammatic view of a data reader 10 in
accordance with a first embodiment shown reading a DPM code 15
etched or otherwise directly marked on an exterior surface 20 of an
item 25, which may be made of a metal, plastic, wood, or other
suitable material. In some applications, the DPM code 15 is
comprised of multiple elements 30 directly imprinted, etched,
molded, or otherwise marked on the item 25. For example, the
exterior surface 20 of a metallic item 25 may be etched such that
the multiple elements 30 are sunken or depressed into the surface
20, or a plastic item 25 may be molded to include raised elements
30 on the exterior surface 20. It should be understood that
although the DPM code 15 is depicted as a sequence of linear
elements 30 in FIG. 1, the DPM code 15 may include symbols,
designs, or other non-linear suitable elements in other
applications.
[0014] With reference to FIG. 1, the data reader 10 is
schematically depicted as a hand-held portable data reader suitable
for reading codes, symbols, or other indicia. The reader 10
includes a housing 35 with a generally elongate handle 40 and a
scan window 45 on an upper body portion 50. The handle 40 includes
a manually actuatable trigger 55 operable to initiate an image
capture process of the DPM code 15 for an item 25 located in a
field of view 60 of the data reader 10. In some embodiments, the
handle 40 (or the upper body portion 50) of the data reader 10 may
include an actuatable input mechanism 65, such as a button or set
of buttons, that allow the user to select or toggle between
different illumination options (as described in further detail with
reference to FIGS. 2-13) for the data reader 10. In other
embodiments, the data reader 10 may be configured as a fixed unit
(mountable to a support surface or free standing on a horizontal
surface) or may be a combined handheld/fixed unit, e.g., one that
may rest/be self-supporting upon a horizontal surface but be
grasped by the user and moved to aim toward an item to be read.
[0015] As mentioned previously, DPM codes 15 are often difficult to
read for various reasons, such as (1) poor contrast between the
marked elements 30 and the exterior surface 20, and/or (2) high
reflectivity (e.g., specular reflection issues) of the exterior
surface 20. Moreover, since the data reader 10 may be used to read
DPM codes 15 marked on a wide variety of surfaces (e.g., metal,
plastic, wood), the severity of the contrast and reflectivity
issues may change depending on the item 25 from which the DPM code
15 is being read. Accordingly, it would be advantageous to
incorporate an illumination system 100, 200, 300, 400 operable to
generate and toggle between different light patterns to provide the
data reader 10 with sufficient flexibility to read DPM codes 15
from a variety of items 25. Example embodiments of such
illumination systems 100, 200, 300, 400 are described in further
detail below with reference to FIGS. 2-12.
[0016] FIGS. 2-4 illustrate an example embodiment of an
illumination system 100 operable to generate multiple light
patterns for the data reader 10. In some example embodiments, the
illumination system 100 uses a common illumination source or
sources 102 and an active element 104 to generate a diffuse light
pattern (FIG. 3) for providing a broad scope of illumination, and a
grazing light pattern (FIG. 4) for providing a smaller, target
scope of illumination, and other light patterns as further
described below. The active element 104 directs light from the
illumination source(s) 102 along an optical path toward various
optical elements of the illumination system 100 to generate the
different light patterns. As is further described in detail below,
the light patterns generated by the illumination system 100 are
preferably dedicated light patterns that are not activated at the
same time to avoid causing potential lighting issues.
[0017] FIG. 2 illustrates a schematic diagram of an illumination
system 100 arranged within the housing 35 of the data reader 10.
With reference to FIG. 2, the illumination system 100 includes a
single source or plurality of illumination sources 102 (such as
light-emitting diodes) operable to direct light toward an active
element 104, which in turn redirects the light from illumination
sources 102 to create different light patterns as briefly mentioned
previously. Preferably, the active element 104 is arranged such
that the active element 104 is substantially centered along the
receiving optical axis A, although the active element 104 may be
located in a different position in alternate embodiments.
[0018] As illustrated in FIGS. 2-4, in one embodiment, the active
element 104 may comprise a liquid lens that uses one or more fluids
to create an infinitely-variable lens without any moving parts by
controlling characteristics of the meniscus (the surface of the
liquid). For example, in one embodiment, the liquid lens 104 may
include a sealed chamber of oil and water having different indices
of refraction, but the same density. Using an electrowetting
process, the shape of the oil drop in the chamber may be controlled
via an electric field to alter the optical path of the light
traveling through the liquid lens 104. As is further described with
reference to FIGS. 3 and 4, the liquid lens 104 is operable via a
controller 105 to redirect light toward different optical
structures to create the diffuse light pattern and the grazing
light pattern.
[0019] The data reader 10 further includes receiving optics 106,
which may include one or more lens assemblies or optical elements
(not shown) operable to focus return light from the DPM code 15 and
item 25 to form an image on an imager 108. The data reader 10
further includes a decoder unit 109 in communication with the
imager 108 and operable to decode the captured DPM code 15. With
particular reference to FIGS. 3 and 4, the following section
describes further details of the optics arrangement of the
illumination system 100 used to generate different light patterns
for aiding the image-capture and decoding process of the data
reader 10.
[0020] FIG. 3 is a schematic diagram illustrating an example
optical path for light generated by the illumination sources 102 to
create a diffuse light pattern that broadly scatters light from the
data reader 10 toward the DPM code 15 and the item 25. The diffuse
light pattern may be useful for reading DPM codes 15 from items 25
that may have high surface reflectivity, such as for items 25
having mirror-like or other highly reflective surfaces. Certain
components of the data reader 10 have been removed in FIG. 3 for
simplicity and to avoid obscuring more pertinent details of the
embodiment.
[0021] With reference to FIG. 3, the illumination sources 102
generate a first light 102a directed toward the liquid lens 104.
The controller 105 generates an electrical current to alter the
optical properties of the liquid lens 104 such that the lens 104
redirects the light as a second light 102b forwardly toward a
mirror 112. In one embodiment, the mirror 112 includes a plurality
of holes, apertures, or other passages 114 formed thereon to allow
the light 102b to travel therethrough. In other embodiments, the
mirror 112 may include a plurality of individual mirrors spaced
apart from each other to create gaps and form a passageway for the
light 102b.
[0022] The light 102b redirected by the liquid lens 104 travels
forwardly through the apertures or gaps 114 in the mirror 112 and
toward a window 116 positioned at a front end of the data reader
10, the window 116 comprising transmissive and diffusive optical
properties to diffuse the light 102b. Some of the diffused light
102c passes through the window 114, while other light 102d is
diffused inwardly within the housing 35 of the data reader 10. The
diffused light 102d travels rearwardly and/or sidewardly away from
the window 116 and toward a wall 118. The wall 118, comprising both
diffusive and reflective optical properties, again
diffuses/scatters the light 102e and reflects the light 102e back
toward the window 116, where the light 102f illuminates the item
25.
[0023] In some embodiments, the wall 118 may have a generally
arcuate or curved profile with end portions 128, 130 adjacent to
and offset from the mirror 112 to provide sufficient spacing 132
between the end portions 128, 130 to provide a clear passageway for
the light traveling through or between the mirror 112. In other
embodiments, end portions 120, 122 of the wall 118 are fixedly
attached to end portions 124, 126, respectively, of the window 116
to minimize any gaps and avoid having light escape therebetween.
Accordingly, most of the light generated by the illumination
sources 102 travels out the window 114 to illuminate the DPM code
15 on the item 25.
[0024] FIG. 4 is a schematic diagram illustrating an example
optical path for light generated by the illumination sources 102 to
create a grazing light pattern that yields a more narrowly focused
pattern of light toward the item 25 as compared to the diffuse
light pattern of FIG. 3. In some embodiments, the grazing light
pattern may be useful to provide sufficient illumination for item
surfaces comprising engraved scannable media (e.g., engraved in
plastic or metal surface).
[0025] With reference to FIG. 4, the illumination system 100
includes a pair of collimating mirrors 134, 136 laterally offset
from one another and generally positioned on opposing sides of the
liquid lens 104. In an example operation, the illumination sources
102 generate a first light 103a, which is directed toward the
liquid lens 104. The liquid lens 104 in turn redirects the light as
a second light 103b toward the mirror 112. An upper portion 112a of
the mirror 112 redirects the light 103c sidewardly and rearwardly
toward the collimating mirror 134, and a lower portion 112b of the
mirror 112 redirects the light 103d sidewardly and rearwardly
toward the collimating mirror 136. The collimating mirrors 134, 136
redirect the light 103e, 103f, respectively, forwardly toward an
angled deviation mirror 138, 140. The deviation mirrors 138, 140
redirect the light 103g, 103h outwardly through an exit window 142,
144, respectively, and toward the item 25.
[0026] In some embodiments, the ends 146, 148 of the exit windows
142, 144 may be affixed to the window 116. In addition, or
alternatively, in other embodiments, the deviation mirrors 138, 140
may be attached to the exit windows 142, 144 to ensure that the
light is redirected from the deviation mirrors 138, 140 and toward
the exit windows 142, 144 to minimize the amount of light that
escapes from the housing 35 of the data reader 10.
[0027] As mentioned previously, the illumination system 100
illustrated and described with reference to FIGS. 2-4 uses a common
illumination source 102 and a fixed arrangement of optical
structures, such as a liquid lens 104, mirrors 112, 134, 136, 138,
140, a wall 118, and windows 116, 142, 144 to generate a variety of
light patterns for the data reader 10.
[0028] In other embodiments, one or more of the mirrors 112, 134,
136, 138, 140 may be movable or rotatable within the housing 35 to
provide adaptive control and optimize lighting when desired. For
example, the decoder unit 109 (or other processor) may be in
operable communication with the deviation mirrors 138, 140 to
rotate one or both mirrors 138, 140 based on sampled images of the
DPM code 15 received by the imager 108. In one example, the decoder
unit 109 may attempt to decode the DPM code 15 and during the
decoding step, the decoder unit 109 decodes a partial code but
fails to identify a stop sequence. To obtain the missing
information, the decoder unit 109 may send a signal (or otherwise
instruct another processor or subsystem to send a signal) to rotate
the mirrors 138, 140 and optimize the illumination of the DPM code
15 for a subsequent reading attempt.
[0029] FIGS. 5-8 described in further detail below illustrate
another embodiment of an illumination system 200 that uses a
similar optical arrangement as the embodiment described in FIGS.
2-4 to produce different light patterns and allow the data reader
10 to read DPM codes 15 from an item 25. As is illustrated in FIGS.
5-8, illumination system 200 may include the same or similar
components arranged in the same or similar fashion as those
described in illumination system 100. For ease of reference, such
components may be referred to by the same description and
designated with analogous reference numbering. For example, the
illumination system 200 includes receiving optics 206, a
transmissive, diffusive window 216, a reflective, diffusive wall
218, collimating mirrors 234, 236, deviation mirrors 238, 240, and
exit windows 242, 244. It should be understood that in some
embodiments these components are arranged and operate in a similar
fashion as those described previously with respect to the
illumination system 100 unless otherwise stated. Accordingly,
additional details of these components are not further described in
detail to avoid repetition.
[0030] FIG. 5 illustrates a schematic diagram of an illumination
system 200 arranged within the housing 35 of the data reader 10 for
generating illumination to allow the data reader 10 to read a DPM
code 15 on an item 25. With reference to FIG. 5, the illumination
system 200 includes a plurality of illumination sources 202
operable to generate RGB (red, green, blue) light, and an active
driver 204 in communication with the illumination sources 202 to
control the wavelength of light (i.e., the color of light) produced
by the illumination sources 202. As is explained in further detail
below, the selected wavelength of light produced by the
illumination sources 202 allows the data reader 10 to generate
multiple light patterns.
[0031] The illumination system 200 further includes a first mirror
pair 250 and a second mirror pair 255. The mirror pairs 250, 255
each comprise a first mirror 250a, 255a, and a second mirror 250b,
255b, where the first mirrors 250a, 255a are aligned relative to
one another and offset from the optical axis A, and the second
mirrors 250b, 255b are also aligned relative to one another and
offset from the optical axis A. The mirror pairs 250, 255 each
include wavelength selective reflective optics (e.g., a multilayer
coating tuned to a specific wavelength) so as to reflect light of a
specific wavelength and otherwise allow other light of a different
wavelength to pass through. For example, in the embodiment
described with respect to FIGS. 6 and 7, the first and second
mirrors 250a, 250b in the mirror pair 250 may each be coated to
reflect light having a wavelength that corresponds to red light
(e.g., a wavelength ranging between 620-750 nm), and the first and
second mirrors 255a, 255b in the mirror pair 255 may each be coated
to reflect light having a wavelength that corresponds to blue light
(e.g., a wavelength ranging between 450-495 nm). It should be
understood that in other embodiments, the coating on the mirror
pairs 250, 255 may be different than the embodiment described to
allow different wavelengths to reflect or pass through as desired.
For example, mirrors 250a, 250b may be coated to reflect blue
light, and the mirrors 255a, 255b may be coated to reflect red
light, or the mirrors 250a, 250b may be coated to reflect green
light and the mirrors 255a, 255b may be coated to reflect blue
light. It should be understood that any combination of wavelength
selective reflective optics may be used in conjunction with the
mirrors 250, 255 without departing from the principles of the
described embodiments.
[0032] The illumination system 200 further includes a lens group
260 comprising a first lens 260a and a second lens 260b offset from
one another. In some embodiments, the first lens 260a is aligned
with the first mirrors 250a, 255a of each of the first and second
mirror pairs 250, 255, and the second lens 260b is aligned with the
second mirrors 250b, 255b. The lens group 260 is operable to focus
light received from the illumination sources 202 through the window
216 and onto the item 25. As further described in detail below with
respect to FIGS. 6-8, the mirror pairs 250, 255 and the lens group
260 cooperate to allow the data reader 10 to generate multiple
light patterns as needed. The following describes examples of
different light patterns that the data reader 10 is capable of
generating using the common light source 202 and optical
arrangement.
[0033] With reference to FIG. 6, in one embodiment, the active
driver 204 sends a signal to the illumination source 202 to produce
light having a wavelength in the red spectrum, thereby producing
red light 202a. The red light 202a is directed toward the first
mirror pair 250 coated to reflect red light, at which the light
202b is reflected sidewardly and rearwardly by the first mirror
250a toward the collimating mirror 234. The collimating mirror 234
in turn redirects the red light 202c forwardly toward the deviation
mirror 238, which directs the red light 202d through the exit
window 242 to illuminate the item 25 with a grazing light pattern.
Red light 202a' follows a similar optical path off the second
mirror 250b, the collimating mirror 236, the deviation mirror 240,
and exits through the window 244 to illuminate the item 25.
[0034] With reference to FIG. 7, in another embodiment, the active
driver 204 sends a signal to the illumination source 202 to produce
light having a wavelength in the blue spectrum, thereby producing
blue light 203a. The blue light 203a is directed toward the first
mirrors 250a, 250b. Since the first mirrors 250a, 250b are each
coated to reflect red light but otherwise allows other colored
light to pass through, the blue light 203a passes through the first
mirrors 250a, 250b and toward the second mirrors 255a, 255b. When
the blue light 203a reaches the second mirrors 255a, 255b, the blue
light 203b is redirected toward the reflective, diffusive wall 218,
where the blue light 203c is reflected and diffused toward the
window 216. Thereafter, the blue light 203e exits the window 216 to
illuminate the item 25 with a diffuse light pattern.
[0035] With reference to FIG. 8, in another embodiment, the active
driver 204 sends a signal to the illumination source 202 to produce
light having a wavelength for the green spectrum, thereby producing
green light 205a. The green light 205a passes through both the
first mirrors 250a, 255b and the second mirrors 255a, 255b without
being redirected since none of the mirrors 250a, 250b, 255a, 255b
includes a coating tuned specifically for green light 205a.
Accordingly, the green light 205a passes through the mirrors 250a,
250b, 255a, 255b and reaches the lens group 260, where the green
light 205b is focused by the lens group 260 through a hole or gap
265 (enlarged in FIG. 8 for illustration purposes) formed on the
window 216. The green light 205b passes through the gap 265 of the
window 216 and illuminates the item 25 with a bright light
pattern.
[0036] The embodiments described in FIGS. 5-8 illustrate another
embodiment of the illumination system 200 having an active driver
204 operable to generate a specific wavelength of light from the
illumination sources 202. Depending on the wavelength of the
generated light, the light reacts with passive, stationary elements
(e.g., the mirrors 250, 255 or the lens group 260) to produce
different light patterns for the data reader 10.
[0037] With reference to FIGS. 9-11, the following illustrates yet
another embodiment of an illumination system 300 that uses a
similar optical arrangement as the embodiments described previously
to produce different light patterns and allow the data reader 10 to
read DPM codes 15 from an item 25. As is illustrated in FIGS. 9-11,
the illumination system 300 may include the same or similar
components arranged in the same or similar fashion as those
described in illumination systems 100, 200. Accordingly, to avoid
repetition, such similar components will not be further described
in detail. For ease of reference, such components may be referred
to using the same description and designated with analogous
reference numbering.
[0038] FIG. 9 illustrates a schematic diagram of an illumination
system 300 arranged within the housing 35 of the data reader 10 for
generating illumination to allow the data reader 10 to read a DPM
code 15 from an item 25. With reference to FIG. 9, the illumination
system 300 includes a single or plurality of illumination sources
302 (such as light-emitting diodes) operable to direct light toward
an active element 304, which in turn redirects the light from
illumination sources 302 to create different light patterns. As
illustrated in FIG. 9, in one embodiment, the active element may
comprise mirrors 304a, 304b, where each of the mirrors 304a, 304b
is movable or translatable along an axis B. As is further described
in detail below with reference to FIGS. 10 and 11, based on the
position of the mirrors 304a, 304b, the light generated by the
illumination sources 302 is redirected toward different optical
structures to generate different light patterns for improved data
reading.
[0039] The illumination system 300 includes a driver mechanism 305
in operable communication with a processor 307 and with the
mirrors304a, 304b. The mirror pair 304 includes a first mirror 304a
and a second mirror 304b, each of which is movable or translatable
along an axis B (see FIGS. 10-11). The axis B is preferably offset
and parallel to the optical axis A and also offset from the
diffusive wall 318 to allow the mirror pair 304 to move along the
axis B and relative to the diffusive wall 318 without obstruction
as further described below.
[0040] FIG. 10 illustrates an embodiment of the illumination system
300 for generating a grazing light pattern. With general reference
to FIGS. 9-10, in response to receiving a user selection of the
grazing light pattern (such as via the input mechanism 65 on the
data reader 10), the processor 307 transmits a signal to the driver
mechanism 305 to position the mirror pair 304 in accordance with
the selected light pattern. In some embodiments, the mirrors 304a,
304b may be positioned on a track (not shown) and the driver
mechanism 305 may move the mirrors 304a, 304b along the track in
response to instructions from the processor 307.
[0041] To generate a grazing light pattern, the driver mechanism
305 moves the Mirrors 304a, 304b along the axis B to a first
position, at which the mirrors 304a, 304b are each outside and in
front of the diffusive wall 318. With the mirrors 304a, 304b in the
first position, the light 302a, 302b generated by the illumination
sources 302 is reflected sidewardly by the mirrors 304a, 304b
toward the collimating mirrors 334, 336. The collimating mirrors
334, 336 in turn redirect the light 302c, 302d forwardly toward the
deviation mirrors 338, 340, which in turn direct the light 302e,
302f through the exit windows 342, 344, where light 302g, 302h
illuminates the item 25.
[0042] In some embodiments, the driver mechanism 305 and processor
307 may be further operable to rotate the mirrors 304a, 304b about
the axis B to adjust the angle of the grazing light pattern exiting
from the windows 342, 344 to adjust or tailor the grazing light
pattern as needed. In addition, as noted in previous embodiments,
the deviation mirrors 338, 340 may also be rotated to adjust the
grazing light pattern exiting the windows 342, 344.
[0043] FIG. 11 illustrates an embodiment of the illumination system
300 for generating a diffuse light pattern. With general reference
to FIGS. 9 and 11, in response to receiving a user selection of the
diffuse light pattern, the processor 307 transmits a signal to the
driver mechanism 305 to position the mirrors 304a, 304b in
accordance with the selected light pattern. To generate a diffuse
light pattern, the driver mechanism 305 moves the mirrors 304a,
304b along the axis B to a second position, at which the mirrors
304a, 304b are generally housed within the diffusive wall 318. With
the mirrors 304a, 304b in the second position, the illumination
sources 302 generate illumination 303a, 303b directed toward the
mirrors 304a, 304b, which redirects light 303c, 303d sidewardly
toward the reflective, diffusive wall 318. The wall 318 in turn
diffuses and reflects light 303e, 303f toward the window 316,
through which the light 303g, 303h exits to illuminate the item
25.
[0044] FIGS. 12 and 13 illustrate another embodiment of an
illumination system 400 that uses a similar optical arrangement as
the previously described embodiments to produce different light
patterns and allow the data reader 10 to read DPM codes 15 from an
item 25. As is illustrated in FIGS. 12-13, illumination system 400
may include the same or similar components arranged in the same or
similar fashion as those described in illumination systems 100,
200, 300. Accordingly, to avoid repetition, such similar components
will not be further described in detail. For ease of reference,
such components may be referred to by the same description and
designated with analogous reference numbering.
[0045] FIG. 12 illustrates a schematic diagram of an illumination
system 400 arranged within the housing 35 of the data reader 10 for
generating illumination to aid the data reader 10 in reading the
DPM code 15 from the item 25. With reference to FIG. 12, the
illumination system 400 includes a plurality of illumination
sources 402 operable to generate RGB (red, green, blue) light, or
other colored lights in other embodiments. The illumination sources
402 may include dedicated colored light sources 402a, 402b, 402c,
each generating light at a specific wavelength to produce
individual beams of red, green, and blue light. It should be
understood that while the foregoing written description may
associate a specific light color with each of the sources 402a,
402b, 402c, this designation is for convenience purposes only and
not meant to be limiting.
[0046] With reference to FIGS. 12 and 13, the plurality of
illumination sources 402 are activated to direct colored light to
various different optical structures to generate different light
patterns for the data reader 10. Preferably, both the red and blue
light sources 402a, 402b are positioned between the wall 416 and
the window 418. In some embodiments, the blue light source 402a
directs light 403a toward a lens group 460. The lens group 460
receives blue light 403a and focuses blue light 403b through one or
more holes, gaps, or apertures 465 formed on the window 416, where
light 403c illuminates the item 25 with a bright light pattern. The
red light source 402b, which is offset from the blue light source
402a, directs red light 404a toward the reflective, diffusive wall
416, where red light 404b is reflected and diffused toward the
window 416. The red light 404c exits the window 416 to provide a
diffused light pattern and illuminate the item 25. The green light
source 402c is arranged outside the wall 416 and directs green
light 405d forwardly toward the deviation mirrors 438, 440. The
deviation mirrors 438, 440 in turn direct the green light 403e
through the exit windows 442, 444 to illuminate the item 25.
[0047] In some embodiments, some or all of the colored illumination
sources 402 may be activated simultaneously to generate three
different colored light patterns. In such embodiments, the data
reader 10 may further include a color sensor, such as an RGB
sensor, 470 operable to detect the reflected light from the DPM
code 15 and determine which light source (e.g., which of the
colored illumination) best captures the DPM code 15. In some
embodiments, the color sensor 470 may be an integral component of
the imager 408 or may be a standalone unit in operable
communication with the imager 408.
[0048] It is intended that subject matter disclosed in any one
portion herein can be combined with the subject matter of one or
more other portions herein as long as such combinations are not
mutually exclusive or inoperable. In addition, many variations,
enhancements and modifications of the imager-based optical code
reader concepts described herein are possible.
[0049] The terms and descriptions used above are set forth by way
of illustration only and are not meant as limitations. Those
skilled in the art will recognize that many variations can be made
to the details of the above-described embodiments without departing
from the underlying principles of the invention.
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