U.S. patent application number 15/094260 was filed with the patent office on 2017-10-12 for imaging module and reader for, and method of, reading a target by image capture through a window in direct, sealed contact with the module.
The applicant listed for this patent is SYMBOL TECHNOLOGIES, LLC. Invention is credited to EDWARD D. BARKAN, MARK E. DRZYMALA, DARRAN M. HANDSHAW.
Application Number | 20170293785 15/094260 |
Document ID | / |
Family ID | 58503698 |
Filed Date | 2017-10-12 |
United States Patent
Application |
20170293785 |
Kind Code |
A1 |
HANDSHAW; DARRAN M. ; et
al. |
October 12, 2017 |
IMAGING MODULE AND READER FOR, AND METHOD OF, READING A TARGET BY
IMAGE CAPTURE THROUGH A WINDOW IN DIRECT, SEALED CONTACT WITH THE
MODULE
Abstract
A light-transmissive window is positioned in direct, sealing
contact with a chassis of an imaging module for reading a target by
image capture. The chassis has a plurality of interior
compartments, each having an opening. An imager, an aiming light
source, and an illuminating light source are mounted on a common
printed circuit board and individually contained in the
compartments. The window covers each opening and environmentally
seals, optically isolates, and resists entry of the light from the
aiming and/or illuminating light sources into, the interior
compartment.
Inventors: |
HANDSHAW; DARRAN M.; (SOUND
BEACH, NY) ; BARKAN; EDWARD D.; (MILLER PLACE,
NY) ; DRZYMALA; MARK E.; (SAINT JAMES, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SYMBOL TECHNOLOGIES, LLC |
LINCOLNSHIRE |
IL |
US |
|
|
Family ID: |
58503698 |
Appl. No.: |
15/094260 |
Filed: |
April 8, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06K 7/10722 20130101;
G06K 7/1413 20130101; G06K 2207/1011 20130101; G06K 7/10831
20130101 |
International
Class: |
G06K 7/10 20060101
G06K007/10; G06K 7/14 20060101 G06K007/14 |
Claims
1. An imaging module for reading a target by image capture, the
imaging module comprising: a chassis having first chassis walls
bounding a first interior compartment having a first opening, the
chassis walls terminating in outer wall surfaces of the chassis at
the opening; a light source supported within the chassis and
outside the first interior compartment, the light source to emit
light; an imager contained in the first interior compartment, the
imager to capture an image through the first opening over a field
of view; and a light-transmissive window positioned in direct
contact with the outer wall surfaces of the chassis and covering
the first opening, the window environmentally sealing, optically
isolating, and resisting entry of the emitted light into, the first
interior compartment.
2. The module of claim 1, further comprising second chassis walls
bounding a second interior compartment having a second opening,
wherein: the light source is an aiming light source contained in
the second interior compartment and mounted on a printed circuit
board (PCB), the aiming light source to emit the light as an aiming
light through the second opening; and the first and second chassis
walls extend away from the PCB in a direction generally
perpendicular to the PCB.
3. The module of claim 1, further comprising second chassis walls
bounding a second interior compartment having a second opening,
wherein: the light source is an illuminating light source contained
in the second interior compartment and mounted on a printed circuit
board (PCB), the illuminating light source to emit the light as an
illuminating light through the second opening; and the first and
second chassis walls extend away from the PCB in a direction
generally perpendicular to the PCB.
4. The module of claim 1, wherein the light source is an indicating
light source to emit the light as a visual indicating light when
the target has been successfully read.
5. The module of claim 1, wherein: the light source is at least one
of an aiming light source to generate an aiming light, and an
illuminating light source to generate an illuminating light; and
the imager and the at least one of the aiming light source and the
illuminating light source are mounted on a printed circuit
board.
6. The module of claim 1, wherein the window is fixedly mounted on
the chassis.
7. The module of claim 1, further comprising: second chassis walls
bounding a second interior compartment having a second opening,
wherein the light source is a first light source contained in the
second interior compartment and mounted on a generally planar
printed circuit board (PCB); and third chassis walls bounding a
third interior compartment having a third opening; and a second
light source contained in the third interior compartment and
mounted on the PCB, wherein the window is in direct, sealed contact
with edges of the first, second and third chassis wall
surfaces.
8. An imaging reader for reading a target by image capture, the
reader comprising: a housing having an interior; and an imaging
module mounted in the interior of the housing, the module
including: a chassis having first chassis walls bounding a first
interior compartment having a first opening, the chassis walls
terminating in outer wall surfaces; a light source supported within
the chassis and outside the first interior compartment; an imager
contained in the first interior compartment to capture an image
through the first opening over a field of view; and a
light-transmissive window positioned in direct contact with the
outer wall surfaces and covering the first opening, the window
environmentally sealing, optically isolating, and resisting entry
of the emitted light into, the first interior compartment.
9. The reader of claim 8, first comprising second chassis walls
bounding a second interior compartment having a second opening,
wherein: the light source is an aiming light source contained in
the second interior compartment and mounted on a printed circuit
board (PCB), the aiming light source to generate an aiming light
through the second opening; and the first and second chassis walls
extend away from the PCB in a direction generally perpendicular to
the PCB.
10. The reader of claim 8, further comprising second chassis walls
bounding a second interior compartment having a second opening,
wherein: the light source is an illuminating light source contained
in the second interior compartment and mounted on a printed circuit
board (PCB), the illuminating light source to generate an
illuminating light through the second opening; and the first and
second chassis walls extend away from the PCB in a direction
generally perpendicular to the PCB.
11. The reader of claim 8, wherein the light source is an
indicating light source to generate a visual indicating light when
the target has been successfully read.
12. The reader of claim 8, wherein: the light source is at least
one of an aiming light source to generate an aiming light and an
illuminating light source to generate an illuminating light; and
the imager and the at least one of the aiming light source and the
illuminating light source are mounted on a printed circuit
board.
13. The reader of claim 8, wherein the window is fixedly mounted on
the chassis and is environmentally sealed with the housing.
14. The reader of claim 8, further comprising: second chassis walls
bounding a second interior compartment having a second opening,
wherein the light source is a first light source contained in the
second interior compartment and mounted on a printed circuit board
(PCB); third chassis walls bounding a third interior compartment
having a third opening; a second light source contained in the
third interior compartment and mounted to the PCB, wherein the
window is in direct, sealed contact with edges of the first, second
and third chassis wall surfaces.
15. A method comprising: configuring a chassis with first chassis
walls bounding a first interior compartment having a first opening;
configuring the chassis walls to terminate at outer wall surfaces
at the first opening; mounting a light source outside the first
interior compartment, the light source to emit light; mounting an
imager within the first interior compartment such that the imager
captures an image through the first opening over a field of view;
and environmentally sealing, optically isolating, and resisting
entry of the emitted light into, the first interior compartment by
positioning a light-transmissive window in direct contact with the
outer wall surfaces and in a covering relationship with the first
opening.
16. The method of claim 15, further comprising configuring the
chassis with second chassis walls bounding a second interior
compartment having a second opening wherein mounting the light
source comprises mounting the light source within the second
interior compartment such that the light source emits light through
the second opening; and configuring the first and second chassis
walls to extend away from a printer circuit board (PCB).
17. (canceled)
18. The method of claim 15, further comprising configuring the
light source as an indicating light source for directing the
emitted light as a visual indicating light when a target has been
successfully read.
19. The method of claim 15, further comprising configuring the
light source as at least one of an aiming light source for
directing the emitted light as an aiming light, and an illuminating
light source for directing an illuminating light; and mounting the
imager and the at least one of the light source and the
illuminating light source on a printed circuit board.
20. The method of claim 15, wherein positioning the window in
direct contact with the outer wall surfaces comprises fixedly
mounting the window on the chassis.
Description
BACKGROUND OF THE INVENTION
[0001] The present disclosure relates generally to an imaging
module and an imaging reader for, and a method of, reading a
target, such as a bar code symbol, to be electro-optically read by
image capture over a field of view through a window that is
positioned in direct, sealed contact with the module, and, more
particularly, to preventing light from aiming and/or illuminating
and/or indicating and/or object sensing systems onboard the module
from interfering with a successful reading of the target.
[0002] Solid-state imaging readers have long been used, in both
handheld and hands-free modes of operation, in many industries,
such as retail, manufacturing, warehousing, distribution, postal,
transportation, logistics, etc., to electro-optically read targets,
such as one- or two-dimensional bar code symbols to be decoded. A
known imaging reader generally includes a housing having a window,
and an imaging module, also known as a scan engine, mounted in the
hosing at a spacing from the window. The module has a chassis with
a plurality of interior compartments. An aiming light system, which
has an aiming light source contained in one of the compartments,
directs one or more visible aiming lights through the window to a
target to visually locate the target and, thus, advise an operator
which way the reader is to be pointed in order to position the
aiming lights on the target, prior to reading. An illuminating
system, which has an illuminating light source contained in another
of the compartments, emits one or more illuminating lights through
the window toward the target to illuminate the target, especially
in dimly lit environments. An imaging system, which has a
solid-state imager contained in still another of the compartments,
captures an image of the target through the window over a field of
view. An indicating system, which has an indicating light source
supported on the chassis, emits an indicating light that visually
indicates when the target has been successfully read. An object
sensing system, which has a wakeup light source supported on the
chassis, emits an object sensing light at the target to detect the
entry of the target into the field of view. These systems are
generally located in close proximity with one another on the
chassis, especially when a small-sized chassis is desired for a
particular reader.
[0003] Although generally satisfactory for their intended purpose,
the close mutual proximity of these systems could cause the aiming
and/or illuminating and/or indicating and/or object sensing lights
to stray and leak into the compartment containing the imager, and
such cross-talk could interfere with a successful imaging and
reading of the target. This leakage is exacerbated by the
spaced-apart window, which could rearwardly reflect, for example,
the aiming and/or illuminating lights back to the imaging system in
the chassis. In addition, the aiming and/or illuminating and/or
object sensing lights could stray and leak to the indicating system
and erroneously indicate that a target has been successfully read.
Furthermore, dust, moisture, dirt, and like contaminants could
migrate not only among the systems and interfere with their
performance, but also could be deposited on the spaced-apart
window. Reflections of the aiming and/or illuminating and/or object
sensing lights from such contaminants on the window could create
bright spots in the captured image and further degrade reading
performance.
[0004] Accordingly, it would be desirable to environmentally seal,
optically isolate, and resist entry of stray aiming and/or
illuminating and/or indicating and/or object sensing light into,
the compartment containing the imager, to mitigate stray internal
reflections, and to improve overall reading performance.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0005] The accompanying figures, where like reference numerals
refer to identical or functionally similar elements throughout the
separate views, together with the detailed description below, are
incorporated in and form part of the specification, and serve to
further illustrate embodiments of concepts that include the claimed
invention, and explain various principles and advantages of those
embodiments.
[0006] FIG. 1 is a perspective view of an exemplary embodiment of
an electro-optical handheld reader for reading targets by image
capture through a window that is positioned in direct, sealed
contact with an imaging module within the reader in accordance with
this disclosure.
[0007] FIG. 2 is a diagrammatic view of components of imaging and
aiming systems onboard the imaging module within the reader of FIG.
1.
[0008] FIG. 3 is an enlarged, front view of components of imaging,
aiming, and illuminating systems on a printed circuit board to be
supported by the imaging module.
[0009] FIG. 4 is an enlarged, front view of a chassis positioned on
the printed circuit board of FIG. 3.
[0010] FIG. 5 is a sectional view taken on line 5-5 of FIG. 3.
[0011] FIG. 6 is a sectional view taken on line 6-6 of FIG. 3.
[0012] FIG. 7 is a broken-away, sectional view depicting the
imaging module mounted in the reader of FIG. 1.
[0013] FIG. 8 is a broken-away, top sectional view depicting the
imaging module mounted in the reader of FIG. 1.
[0014] FIG. 9 is a front, perspective view of the window in
isolation in accordance with one embodiment.
[0015] FIG. 10 is a rear, perspective view of another embodiment of
the window in isolation.
[0016] FIG. 11 is a top, sectional view of components of the
imaging and illuminating systems of the reader of FIG. 1.
[0017] FIG. 12 is a side, sectional view of components of the
imaging and illuminating systems of FIG. 7.
[0018] FIG. 13 is an enlarged, broken-away, perspective view
depicting the aiming lights and the illuminating lights exiting the
window, as well as the field of view of the imager entering the
window, of the reader of FIG. 1.
[0019] Skilled artisans will appreciate that elements in the
figures are illustrated for simplicity and clarity and have not
necessarily been drawn to scale. For example, the dimensions and
locations of some of the elements in the figures may be exaggerated
relative to other elements to help to improve understanding of
embodiments of the present invention.
[0020] The imaging module, the imaging reader, and the method
components have been represented where appropriate by conventional
symbols in the drawings, showing only those specific details that
are pertinent to understanding the embodiments of the present
invention so as not to obscure the disclosure with details that
will be readily apparent to those of ordinary skill in the art
having the benefit of the description herein.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In accordance with one feature of this disclosure, an
imaging module is operative for reading a target, e.g., a bar code
symbol, by image capture. The module includes a chassis having
chassis walls bounding an interior compartment having an opening. A
light source for emitting light is supported by the module. An
imaging system has an imager, e.g., a charge coupled device (CCD)
array or a complementary metal oxide semiconductor (CMOS) array of
cells or sensors, which is contained in the interior compartment,
for capturing an image of the target through the opening over a
field of view. A light-transmissive window is positioned in direct
contact with the chassis and covers the opening. The window
environmentally seals, optically isolates, and resists entry of the
emitted light into, the interior compartment.
[0022] Advantageously, the light source may be an aiming light
source for directing the emitted light as an aiming light at the
target, or may be an illuminating light source for directing an
illuminating light at the target, or may be an indicating light
source for directing the emitted light as a visual indicating light
when the target has been successfully read, or may be an object
sensing light source for directing the emitted light as an object
sensing light at the target to detect the entry of the target into
the field of view. The aiming light source and the illuminating
light source are preferably respectively mounted in other interior
compartments of the chassis, and are mounted, together with the
imager, on a common, generally planar, printed circuit board (PCB).
The chassis walls of all the interior compartments extend away from
the PCB in a direction generally perpendicular to the PCB and
terminate in outer wall surfaces. The window is in direct, sealed
contact with the outer wall surfaces. Preferably, the window is
generally planar, is fixedly mounted on the chassis, and is
positioned to be generally parallel to the PCB.
[0023] In accordance with another feature of this disclosure, the
aforementioned imaging module is mounted in the interior of a
housing of an imaging reader. The housing is preferably embodied as
a portable, point-of-transaction, gun-shaped, handheld housing, but
could be embodied as a handheld, box-shaped housing, or any other
configuration including a hands-free configuration. The window not
only environmentally seals the interior compartments of the module
as described above, but also environmentally seals the interior of
the housing, for example, against dirt, moisture, dust, and like
contaminants.
[0024] In accordance with still another feature of this disclosure,
a method of reading a target by image capture is performed by
configuring a chassis with chassis walls bounding an interior
compartment having an opening, by emitting light from a light
source supported by the chassis, by capturing an image of the
target through the opening over a field of view, and by
environmentally sealing, optically isolating, and resisting entry
of the emitted light into, the interior compartment by positioning
a light-transmissive window in direct contact with the chassis and
in a covering relationship with the opening.
[0025] By so positioning the window in direct, sealed contact with
the outer wall surfaces of the chassis walls, stray aiming and/or
illuminating and/or indicating and/or object sensing lights are
prevented from leaking into the compartment containing the imager,
and stray aiming and/or illuminating and/or object sensing lights
are prevented from leaking to the indicating system. Furthermore,
dust, moisture, dirt, and like contaminants are prevented from
migrating among the systems, and from depositing on the window.
Reading performance is enhanced.
[0026] Turning now to the drawings, reference numeral 30 in FIG. 1
generally identifies a handheld imaging reader for
electro-optically reading targets 24, such as bar code symbols or
like indicia, over an angular field of view (FOV) 20. The reader 30
includes a housing 32 in which an imaging or scan engine or imaging
module 40, as described in detail below in connection with FIGS.
2-8, is mounted. The housing 32 includes a generally elongated
handle or lower handgrip portion 28 and a barrel or upper body
portion having a front end at which a light-transmissive window 26
is located. The cross-sectional dimensions and overall size of the
handle 28 are such that the reader 30 can conveniently be held in
an operator's hand. The body and handle portions may be constructed
of a lightweight, resilient, shock-resistant, self-supporting
material, such as a synthetic plastic material. The plastic housing
32 may be injection molded, but can also be vacuum-formed or
blow-molded to form a thin hollow shell which bounds an interior
space whose volume is sufficient to contain the various components
of this reader 30. A manually actuatable trigger 34 is mounted in a
moving relationship on the handle 28 in a forward facing region of
the reader 30. An operator's forefinger is used to actuate the
reader 30 to initiate reading by depressing the trigger 34.
Although the housing 32 is illustrated as a portable,
point-of-transaction, gun-shaped, handheld housing, this is merely
exemplary, because the housing could also be embodied as a
handheld, box-shaped housing, or with any other configuration
including a hands-free configuration.
[0027] As diagrammatically shown in FIG. 2, the imaging module 40
includes an imaging system having a solid-state imager 10, and an
imaging lens assembly 12 mounted in a tubular holder 14 that has a
circular aperture 16. The imager 10 is a two-dimensional, charge
coupled device (CCD) array or a complementary metal oxide
semiconductor (CMOS) array of cells or sensors having either a
global or a rolling shutter. For low cost reasons, a CMOS imager
may be advantageously used with a rolling shutter. The imager 10
and imaging lens 12 are preferably aligned along a centerline or an
optical imaging axis 18 generally centrally located within the
upper body portion of the housing 32.
[0028] In operation, the imaging system captures return light
passing through an upper central zone 54 of the window 26 along the
imaging axis 18 centered in the imaging field of view 20 of the
imaging lens assembly 12 from the target 24 located in a range of
working distances away from the window 26. The imager 10 is
advantageously positioned closer to a rear wall of the upper body
portion than to a front of the housing 32 in order to enlarge the
imaging field of view 20 in the near range of working distances
close to the reader 30. The imaging lens assembly 12 preferably
comprises one or more fixed-focus lenses, preferably a Cooke
triplet, having an imaging plane at which the target 24 is best
focused and imaged onto the imager 10. The field of view 20 is
generally rectangular and extends along the illustrated mutually
orthogonal, horizontal X-axis and vertical Y-axis (see FIG. 1) that
are both generally perpendicular to the imaging axis 18. The
sensors produce electrical signals corresponding to a
two-dimensional array of pixel information for an image of the
target 24. The electrical signals are processed by a controller or
programmed microprocessor 22 into data indicative of the target 24
being read. The controller 22 is connected to a memory 36 for data
retrieval and storage. The controller 22 and the memory 36 may be
mounted on a printed circuit board (PCB) 38, which is supported by
the module 40, as described below.
[0029] The imaging system is capable of acquiring a full image of
the target 24 under various lighting conditions. An illuminating
system, as described below, may also be mounted on the module 40 to
provide illuminating light to illuminate the target. Exposure time
is controlled by the controller 22. Resolution of the array can be
of various sizes although a VGA resolution of 640.times.480 pixels
may be used to minimize cost.
[0030] An aiming system, including one or more aiming light
assemblies, is supported on the module 40, and is offset from the
imaging system. The aiming system is operative for projecting on
the target 24 an aiming mark 60 (see FIG. 2). The aiming light
assemblies are spaced apart along the horizontal X-axis at opposite
sides of the imaging sensor 10. Each aiming light assembly includes
an aiming light source or emitter, e.g., a light emitting diode
(LED) 42, mounted on the PCB 38; a generally linear aiming aperture
46 that extends along the horizontal X-axis in front of the
respective LED 42; and a toroidal aiming lens 44 mounted away from
its respective LED 42 and, as more fully described below, is
integrated with the window 26. Each aiming LED 42, aiming lens 44
and aiming aperture 46 are centered and lie along a respective
aiming axis 48. The aiming axes 48 generally lie in a common plane
and are generally parallel to one another. As shown, the aiming
LEDs 42 and the sensor 10 are mounted along a common horizontal
axis, but this need not be the case, since the aiming LEDs 42 can
be mounted either above or below the imager 10. Advantageously, the
imaging axis 18 lies in the same plane and is generally parallel to
the aiming axes 48.
[0031] The aiming light assemblies are operative for directing the
aiming light emitted from each aiming LED 42 through the respective
aperture 46 and the respective aiming lens 44 along the respective
aiming axis 48 over an angular aiming field 52 that is centered on
the respective aiming axis 48 at the target 24. On the target 24,
these aiming fields 52 describe a pair of aiming light lines 50,
each having a predetermined brightness. The aiming light lines 50
are collinear along the horizontal X-axis. The aiming light lines
50 have inner linear end regions 50A that extend past the imaging
axis 18 and that overlap on the target 24 to form a bright, linear,
aiming mark 60 having a brightness greater than the predetermined
brightness due to the superposition of the inner linear end regions
50A to visually indicate a center area of the field of view 20 over
the range of working distances. Thus, the operator can position the
aiming mark 60 on the target 24, and the target 24 will be
substantially centered in the imaging field of view 20. The aiming
light lines 50 also have outer linear end regions 50B that extend
along the horizontal X-axis toward, and that visually indicate,
approximate boundary zones or end limits of the field of view 20
over the range of working distances. Thus, the operator is guided
to position the outer linear end regions 50B on the target 24, such
that the target 24 will be substantially contained entirely within
the imaging field of view 20.
[0032] As best seen in FIGS. 5-9, the aiming lenses 44 are formed
of one-piece construction with the window 26 at opposite sides of,
and away from, the upper central zone 54 through which the image of
the target 24 is captured. The window 26 may be constituted of
glass and/or molded plastic materials, and the integrated optical
system includes one or more optical elements, e.g., aiming lenses
44, which may likewise be constituted of glass and/or molded
plastic materials. Thus, the window 26 may be made of glass and
each aiming lens 44 may be made of the same glass. Alternatively,
the window 26 may be made of plastic and each aiming lens 44 may be
made of the same plastic. In other variations, the window 26 may be
made of glass and each aiming lens 44 may be made of plastic that
is deposited or molded onto the glass in a process known as
overmolding or replication, or vice versa, in which the window 26
may be made of plastic and each aiming lens 44 may be made of glass
that is molded into the plastic. Although the aiming lenses 44 are
shown on the outer surface of the window 26, they can also be
formed on the inner surface of the window 26. Thus, the aiming
lenses 44 are integral with the window 26, thereby reducing the
total number of components to be individually fabricated, installed
and aligned.
[0033] As shown in FIGS. 3-4, 6, and 11-12, the reader 30 may also
include an illuminating light system, e.g., one or more
illuminating light sources or emitters, such as light emitting
diodes (LEDs) 62, mounted on the PCB 38. As best shown in FIG. 3,
the aiming light sources 32, the illuminating light sources 62, and
the imager 10 are all surface-mounted on the same PCB 38. In a
variant construction, the illuminating light sources 62 could be
mounted on a separate PCB that preferably is coplanar with the PCB
38. Each illuminating LED 62 is operative for illuminating the
target 24 by emitting illuminating light over an illumination angle
centered on an illumination axis 64 toward the target 24 for
reflection and scattering therefrom. Each illuminating LED 62 is
advantageously provided with an optical element, such as a compound
parabolic reflector (CPR) 66 to uniformly and efficiently
illuminate the target 24 with an illuminating light pattern. Each
CPR 66 is preferably integrated with the window 26 and is
configured to receive, and to optically modify, the illuminating
light emitted from each illuminating LED 62 to generate a generally
uniform and efficient illumination light pattern, preferably of
generally rectangular shape, that is substantially congruent to,
and substantially overlaps, the field of view 20, again preferably
of generally rectangular shape, along both the X- and Y-axes
depicted in FIG. 1. Each CPR 66 has a first pair of parabolic
segments that are located at opposite sides of the illumination
axis 64 for reflecting the emitted illuminating light over a first
illumination angle along the X-axis, and a second pair of parabolic
segments that are also located at opposite sides of the
illuminating axis 64 for reflecting the emitted illuminating light
over a second illumination angle along the Y-axis. Each CPR 66 is
advantageously a solid element, e.g., a molded plastic, whose
interior surfaces reflect and guide the illuminating light away
from each illuminating LED 62 with total internal reflection. Each
CPR 66 could also be a hollow element.
[0034] As best seen in FIG. 10, the CPRs 66 are formed of one-piece
construction with the window 26 at opposite sides of, and below,
the upper central zone 54 through which the image of the target 24
is captured. The window 26 may be constituted of glass and/or
molded plastic materials, and the integrated optical system
includes one or more optical elements, e.g., the CPRs 66, that may
likewise be constituted of glass and/or molded plastic materials.
Thus, the window 26 may be made of glass and each CPR 66 may be
made of the same glass. Alternatively, the window 26 may be made of
plastic and each CPR 66 may be made of the same plastic. In other
variations, the window 26 may be made of glass and each CPR 66 may
be made of plastic that is deposited or molded onto the glass in a
process known as overmolding or replication, or vice versa, in
which the window 26 may be made of plastic and each CPR 66 may be
made of glass that is molded into the plastic. Although the CPRs 66
are shown on the inner surface of the window 26, they can also be
formed on the outer surface of the window 26. Thus, the CPRs 66 are
integral with the window 26, thereby reducing the total number of
components to be individually fabricated, installed and
aligned.
[0035] As best seen in FIGS. 7-8, the window 26 environmentally
seals the interior of the housing 32, for example, against dirt,
moisture, dust, and like contaminants. A rubber gasket or seal 56
helps to seal the window 26 in its position at the front of the
reader 30. As best shown in FIGS. 9-10, a plurality of locating
pins 58 are integrally formed with the window 26 to assist in
mounting the window 26 in its sealed position, and to prevent
rotation of the window 26. One such pin 58 is provided at one side
of the window 26, and a pair of such pins 58 is provided at the
opposite side of the window 26. The locating pins 58 assist in
locating the window 26 accurately with respect to the aiming,
imaging, and illuminating systems. More particularly, the optical
elements on the window 26 are accurately located relative to the
aiming lenses 44, the aiming apertures 46, the aiming LEDs 42, the
CPRs 66, and the illuminating LEDS 62. FIG. 13 depicts the aiming
lights and the illuminating lights exiting the accurately located
window 26, as well as the field of view of the imager 10 entering
the accurately located window 26.
[0036] As best shown in FIGS. 4-8, the module 40 includes a chassis
70 having chassis walls bounding a plurality of interior
compartments 72, 74, and 76, each having an opening. The imager 10
and the imaging lens assembly 12 are contained in the compartment
72. The aiming light sources 42 and the aiming light apertures 46
are respectively contained in a pair of the compartments 74. The
illuminating light sources 62 are respectively contained in a pair
of the compartments 76. The imager 10, the aiming light sources 42,
and the illuminating light sources 62 are all mounted on the same
PCB 38, which is supported at a back wall of the chassis in a
generally upright position. The chassis walls of all the interior
compartments 72, 74, and 76 extend forwardly away from the PCB 38
in a direction generally perpendicular to the PCB 38 and terminate
in outer wall surfaces at each opening.
[0037] In accordance with this disclosure, the window 26 is not
spaced away from the chassis 70, but instead, is positioned in
direct, sealed contact with the chassis 70 and, more particularly,
the window 26 directly engages the outer wall surfaces of the
chassis 70 and covers each opening of each compartment 72, 74, and
76. The chassis walls extend sufficiently forwardly to create
physical barriers among the compartments 72, 74, and 76 to
optically isolate them from one another, and the covering window 26
thus environmentally seals, optically isolates, and resists entry
of any stray aiming and/or illuminating light into, the interior
compartment 72 in which the imager 10 is contained.
[0038] An indicating light source 78 (see FIG. 7) is also supported
on the module 40, preferably rearwardly of the chassis 70 and
mounted on another PCB 82. In a variant construction, the
indicating light source 78 could be mounted in its own interior
compartment in the chassis 70. The indicating light source 78 emits
a visual indicating light to a light scattering section 80 of the
housing 32 whenever the target 24 has been successfully read. The
window 26 not only prevents any stray aiming and/or illuminating
light from leaking to the light scattering section 80 and
erroneously indicating that a target has been successfully read,
but also prevents the visual indicating light from leaking to the
interior compartments, and principally to the compartment 72 in
which the imager 10 is contained.
[0039] The reader 30 may also be provided with an object sensing
system for detecting entry of the target 24 into the field of view
20. The object sensing system includes an object sensing or wakeup
light source for directing the emitted light as an object sensing
light at the target, and an object sensing or wakeup receiver to
detect the return of the emitted light from the target 24. The
window 26 also prevents any stray object sensing light from leaking
to any of the interior compartments, and principally to the
compartment 72 in which the imager 10 is contained.
[0040] The window 26 is either held removably against, or is
fixedly and permanently mounted, for example, by an adhesive or
other fasteners, to the chassis 70. When the window 26 is thus
fixedly mounted, the module 40 is completely sealed and can be
moved around a manufacturing facility, or even shipped to another
facility, without worry of contamination by environmental
contaminants. Advantageously, the window 26 is generally planar and
is positioned to be generally parallel to the PCB 38. The window 26
may also be curved or formed with some other shape, in which the
case, the outer chassis surfaces are configured with a
complementary contour so that a tight seal is made when the window
26 contacts the chassis 70. Although the window 26 is shown as
contacting the chassis 70 at exterior chassis surfaces, it will be
understood that the chassis 70 may also be recessed with a cavity
in which the window 26 is mounted. A recessed window will be more
resistant to scratches and contamination.
[0041] In the foregoing specification, specific embodiments have
been described. However, one of ordinary skill in the art
appreciates that various modifications and changes can be made
without departing from the scope of the invention as set forth in
the claims below. Accordingly, the specification and figures are to
be regarded in an illustrative rather than a restrictive sense, and
all such modifications are intended to be included within the scope
of present teachings.
[0042] The benefits, advantages, solutions to problems, and any
element(s) that may cause any benefit, advantage, or solution to
occur or become more pronounced are not to be construed as a
critical, required, or essential features or elements of any or all
the claims. The invention is defined solely by the appended claims
including any amendments made during the pendency of this
application and all equivalents of those claims as issued.
[0043] Moreover in this document, relational terms such as first
and second, top and bottom, and the like may be used solely to
distinguish one entity or action from another entity or action
without necessarily requiring or implying any actual such
relationship or order between such entities or actions. The terms
"comprises," "comprising," "has," "having," "includes,"
"including," "contains," "containing," or any other variation
thereof, are intended to cover a non-exclusive inclusion, such that
a process, method, article, or arrangement that comprises, has,
includes, contains a list of elements does not include only those
elements, but may include other elements not expressly listed or
inherent to such process, method, article, or arrangement. An
element proceeded by "comprises . . . a," "has . . . a," "includes
. . . a," or "contains . . . a," does not, without more
constraints, preclude the existence of additional identical
elements in the process, method, article, or arrangement that
comprises, has, includes, or contains the element. The terms "a"
and "an" are defined as one or more unless explicitly stated
otherwise herein. The terms "substantially," "essentially,"
"approximately," "about," or any other version thereof, are defined
as being close to as understood by one of ordinary skill in the
art, and in one non-limiting embodiment the term is defined to be
within 10%, in another embodiment within 5%, in another embodiment
within 1%, and in another embodiment within 0.5%. The term
"coupled" as used herein is defined as connected, although not
necessarily directly and not necessarily mechanically. A device or
structure that is "configured" in a certain way is configured in at
least that way, but may also be configured in ways that are not
listed.
[0044] It will be appreciated that some embodiments may be
comprised of one or more generic or specialized processors (or
"processing devices") such as microprocessors, digital signal
processors, customized processors, and field programmable gate
arrays (FPGAs), and unique stored program instructions (including
both software and firmware) that control the one or more processors
to implement, in conjunction with certain non-processor circuits,
some, most, or all of the functions of the method and/or
arrangement described herein. Alternatively, some or all functions
could be implemented by a state machine that has no stored program
instructions, or in one or more application specific integrated
circuits (ASICs), in which each function or some combinations of
certain of the functions are implemented as custom logic. Of
course, a combination of the two approaches could be used.
[0045] Moreover, an embodiment can be implemented as a
computer-readable storage medium having computer readable code
stored thereon for programming a computer (e.g., comprising a
processor) to perform a method as described and claimed herein.
Examples of such computer-readable storage mediums include, but are
not limited to, a hard disk, a CD-ROM, an optical storage device, a
magnetic storage device, a ROM (Read Only Memory), a PROM
(Programmable Read Only Memory), an EPROM (Erasable Programmable
Read Only Memory), an EEPROM (Electrically Erasable Programmable
Read Only Memory) and a Flash memory. Further, it is expected that
one of ordinary skill, notwithstanding possibly significant effort
and many design choices motivated by, for example, available time,
current technology, and economic considerations, when guided by the
concepts and principles disclosed herein, will be readily capable
of generating such software instructions and programs and ICs with
minimal experimentation.
[0046] The Abstract of the Disclosure is provided to allow the
reader to quickly ascertain the nature of the technical disclosure.
It is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. In addition,
in the foregoing Detailed Description, it can be seen that various
features are grouped together in various embodiments for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting an intention that the
claimed embodiments require more features than are expressly
recited in each claim. Rather, as the following claims reflect,
inventive subject matter lies in less than all features of a single
disclosed embodiment. Thus, the following claims are hereby
incorporated into the Detailed Description, with each claim
standing on its own as a separately claimed subject matter.
* * * * *