WO2014011154A1

WO2014011154A1 - Optical aiming system for an image scanner

Info

Publication number: WO2014011154A1
Application number: PCT/US2012/046046
Authority: WO
Inventors: Ken Fukuba; Satoshi Komi
Original assignee: Optoelectronics Co., Ltd.; Opticon, Inc.
Priority date: 2012-07-10
Filing date: 2012-07-10
Publication date: 2014-01-16

Abstract

An optical aiming system for an optical image scanner comprises a fixed-position aiming lens that receives aiming illumination from a fixed-position light source. The aiming lens is dimensioned and configured so that the first optical axis of an image focusing lens of the scanner and a second optical axis of the aiming lens intersect at the focal plane of the image focusing lens and restrict the horizontal width of the aiming illumination to no more than the width of the field of view of the image focusing lens.

Description

OPTICAL AIMING SYSTEM FOR AN IMAGE SCAN NER

Field of the Invention

[oooi] The present invention relates to devices for image scanning, and more particularly to an optical aiming system for use therewith.

Background of the Invention

[0002] Optical image scanning and reading devices read symbols such as barcodes that represent data about a product or service. A barcode is an optical machine-readable label attached to an object, which directly or indirectly represents information about the object or a service associated with the object. Such information can include, without limitation, vendor identification, product name, price, patient name and other descriptive information about the object. Scanning/reading devices are widely used in distribution, retail, and many other industries for reading barcodes.

[0003] Often, such devices are based upon charge-coupled-device (CCD) or CMOS technology, wherein a linear array CCD or CMOS device is used to recover light reflected from the barcode. In such systems, plural "illumination" LEDs are used as a light source to illuminate a target, such as a barcode. The reflected light is imaged by imaging optics onto the CCD or CMOS linear array, which converts the light energy into electrical energy. The varying electrical signal can then be processed to recover the barcode symbol, which represents the information of interest.

[0004] To assist a user in aligning the target (e.g. , barcode, etc.) to be focused by the imaging optics, an aiming beam is generated by focusing light that is generated by one or more "aiming" LEDs onto the target. The location of the target in the proper field of view is aided by projecting an aiming pattern (e.g. , a rectangular shape, etc.) on the target.

[0005] The current trend is to reduce the size and weight of the image scanning and reading device to make it easier to use and less expensive to manufacture. This, in turn, requires the use of a dimensionally more compact imaging module. But miniaturizing the imaging module presents certain challenges.

[0006] Consider, for example, FIG. 1A, which depicts a portion of a typical imaging module. Included in the Figure are image sensor 104, imager optics 106, and elements of a first prior-art aiming system, which includes two aiming LEDs 100A and 100B having respective aiming lenses 102A and 102B. [0007] Imager optics 106 defines field-of-view FOV. Aiming LED 100A on the left side of image sensor 104 generates, within field-of-view FOV, left-side aiming illumination pattern AIP_L. Similarly, aiming LED 100B on the right side of image sensor 104 generates right-side aiming illumination pattern AIP_R. In a perfectly aligned system, patterns AIP_L and AIP_R overlap to providing composite aiming illumination pattern AIP_C of within field-of-view FOV.

[0008] By virtue of using two aiming LEDs, one on each side of image sensor 104, aiming light is emitted symmetrically on an image and helps to provide a user with a sense of distance. The aiming LEDs are, however, susceptible to mechanical misalignment issues, such as can be caused by a sudden impact of a housing incorporating the LEDS against a rigid object. This can cause vertical misalignment of aiming LEDs 100A and 100B and/or aiming lenses 102A and 102B. This, in turn, results in vertical misalignment of patterns AIP_L and AIP_R, as depicted in FIG. IB. As a consequence, an adjustment mechanism is required. That increases the complexity, size, and cost of the imaging module.

[0009] To address the issues resulting from the use of two aiming LEDs, some prior-art aiming systems use a single aiming LED. A system using a single aiming LED is depicted in FIG. 2. The system depicted in FIG. 2 includes aiming LED 200, aiming lens 202, image sensor 104, and imager optics 106.

[ooio] Imager optics 106 defines field-of-view FOV. The single aiming LED 200 generates, within field-of-view FOV, aiming illumination pattern AIP. Having a single aiming LED, this system avoids the potential misalignment problems of the system of FIG. 1A and reduces the cost and size of the aiming system relative to the system of FIG. 1A. But as depicted in FIG. 2, the aiming beam is not symmetric about the optical axis OA of imaging optics 106. As a consequence, the target's position will be off- center, to one side or the other of the field of view. This can be problematic when reading a bar code that is positioned on the edge of the field of view.

[ooii] Compared to lasers, LEDs are not an ideal point source; the light produced by an LED is less focused. As a consequence, an increased line thickness of the projected light results. To reduce line thickness, an aperture or slit 308 is often placed between the aiming lens 302 and the aiming LED 300 in prior-art aiming systems, as depicted in FIG. 3. But the slit disadvantageously reduces the amount of light that is projected onto an object.

[0012] Accordingly, an improved aiming system for an image scanner is needed. Summary of the Invention

[0013] The present invention provides an optical aiming system that avoids some of the drawbacks and costs of the prior art.

[0014] The illustrative embodiment of the present invention is an optical aiming system that includes an aiming light source, such as an LED, and an aiming lens, wherein no aperture is interposed between the light source and the aiming lens. In some embodiments, the optical aiming system is integrated into a camera module, such as is incorporated in an optical image scanner.

[0015] In accordance with the illustrative embodiment, the aiming lens is physically configured and appropriately spaced from the aiming light source to provide the following functionality:

F(l) : To control the horizontal width of the aiming illumination pattern so that it is the same, or slightly narrower than, the horizontal width of the field-of-view of the image focusing lens of the camera module.

F(2) : To efficiently focusing the light in the horizontal direction.

F(3) : To refract the optical axis of the aiming illumination so that it crosses the optical axis of the image focusing lens at or very near to the focal plane of thereof. This ensures that the aiming illumination pattern is centered with respect to the field- of-view of the image focusing lens.

F(4) : To collimate the aiming illumination in the vertical direction.

[0016] In the illustrative embodiment, the aforementioned functionality is achieved as follows:

F(l) : Providing an appropriate curvature to the back surface of the aiming lens restricts the horizontal width of the aiming illumination pattern.

F(2) : Providing a prism, wherein the front surface of the aiming lens refracts the optical axis of the aiming illumination so that it crosses the optical axis of the image focusing lens at or very near to the focal plane of the image focusing lens.

F(3) : Placing the back surface of the aiming lens no more than 8 millimeters from the point at which aiming illumination is emitted from the aiming light source ensures that the light is focused in the horizontal direction.

F(4) : Providing an appropriate curvature to the front surface of the aiming lens (in a direction orthogonal to the linear taper of the prism) collimates the aiming illumination in the vertical direction. The front surface should be at least 10 millimeters from the point at which aiming illumination is emitted from the aiming light source to ensure that the light is collimated. [0017] In addition to the functionality and characteristics disclosed above, in some embodiments, the aiming lens is directly mounted to one of the "boards" that comprises the camera module. Mounting is facilitated by bosses that are integral to the aiming lens. The bosses are received by holes, etc. , in the board, so that the aiming lens resides in a specific and fixed position on the board; it is not adjustable. In the assembled camera module, the back surface of the aiming lens is in close proximity to the aiming light source, which is also fixed in position. As such, in conjunction with the various boards of camera module, this fifth functionality is provided - the aiming lens is "automatically" aligned with the aiming light source.

[0018] In various embodiments, the optical aiming system possesses some, but not all of functionalities F(l) through F(5) . Table 1 below provides a non-limiting listing of embodiments of the optical aiming system as defined by the various functionalities F(l) through F(5) :

Table 1: Functionality of Embodiments of the Invention

Embodiments that provide less than full F(l) through F(5) functionality need not include the features responsible for providing the (omitted) functionality.

Brief Description of the Drawings

[0019] FIG. 1A depicts a first prior-art optical aiming system for use in conjunction with an image scanner.

[0020] FIG. IB depicts a misalignment that can occur with the prior-art aiming system of FIG. 1A.

[0021 ] FIG. 2 depicts a second prior-art optical aiming system for using in conjunction with an image scanner. [0022] FIG. 3 depicts the use of an aperture in conjunction with an aiming LED in the prior art.

[0023] FIG. 4 depicts a camera module of a miniature imager and decoder including an optical aiming system in accordance with the illustrative embodiment of the present invention.

[0024] FIG. 5 depicts the salient elements of the optical aiming system of FIG. 4.

[0025] FIG. 6 depicts the functioning of the optical aiming system of FIG. 4.

[0026] FIG. 7 depicts further detail of the functioning of the optical aiming system of FIG. 4.

[0027] FIG. 8A depicts a side view of the aiming lens of FIG. 5.

[0028] FIG. 8B depicts an aspect of the optical functioning of the rear surface of the aiming lens of FIG. 8A

[0029] FIG. 8C depicts an aspect of the optical functioning of the front surface of the aiming lens of FIG. 8A.

[0030] FIG. 9A depicts an end view of the aiming lens of FIG. 5.

[0031] FIG. 9B depicts an aspect of the optical functioning of the front surface of the aiming lens of FIG. 9A.

[0032] FIG. 10 depicts further performance and design aspects of the optical functioning of the optical aiming system of FIG. 4.

[0033] FIG. 11 depicts the radiation pattern of an LED suitable for use in conjunction with the illustrative embodiment of the present invention.

Detailed Description

[0034] As used herein, spatial or directional terms, such as "left", "right", "inner", "outer", "above", "below", and the like, relate to the invention as it is shown in the drawing figures. It is to be understood, however, that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Further, as used herein, all numbers expressing dimensions, physical characteristics, and the like, used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical values set forth in this specification and appended claims may vary depending upon the desired properties sought to be obtained by the present invention. Moreover, all ranges disclosed herein are to be understood to encompass the beginning and ending range values and any and all sub-ranges subsumed therein. For example, a stated range of "1 to 10" should be considered to include any and all sub-ranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all sub-ranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less, e.g ., 1 to 3.3, 4.7 to 7.5, 5.5 to 10, and the like.

[0035] FIG. 4 depicts an exploded view of camera module 400. The camera module, in conjunction with a decoder module, is a key element of an imaging and decoding module, as found in an image scanning and reading device (e.g. , barcode reader, etc.) . The camera module, which includes the optical aiming system to which the present invention is directed, is discussed briefly for context. Only those aspects of camera module 400 that are germane to the present invention or are otherwise useful for context will be discussed.

[0036] Camera module 400 includes illumination system printed circuit board ("PCB") 410, camera body 420, and image sensor PCB 430. Illumination system PCB 410 mounts to front surface 422 of camera body and image sensor PCB 430 mounts to its back surface 424.

[0037] Illumination system PCB 410 includes aiming lens 450, two illumination LEDs 412, first aperture 414, mounting holes 416, and second aperture 418. Aiming lens 450, which is depicted in further detail in FIG. 5, includes front surface 552, rear surface 554, and bosses 556. The bosses facilitate mounting aiming lens 450 to illumination system PCB 410. Locating features on illumination system PCB 410, such as mounting holes 416, receive bosses 556 at a particular location thereby insuring that aiming lens 450 is precisely positioned on the illumination system PCB. Such precise positioning is required so that the aiming lens is properly positioned with respect to the aiming light source, as discussed further below. By virtue of this arrangement, no adjustment/alignment mechanism is required to achieve the desired optical performance.

[0038] With continuing reference to FIG. 4, camera body 420 includes cylindrical receiver 425. The camera body can be formed from any suitable material, including, without limitation, plastic resin. Image focusing lens 440 is mounted in cylindrical receiver 425 and extends through second aperture 418 in illumination system PCB 410. The image focusing lens can be a variable focus or a fixed focus lens set.

[0039] Image sensor PCB 430 includes aiming light source 432 and image sensor 434. Image focusing lens 440 focuses, onto image sensor 434, light that is reflected from the object being interrogated (e.g. , barcode, etc.) and which originates from illumination LEDs 414. In the illustrative embodiment, the aiming light source 432 is an LED. It is understood, however, that in other embodiments, the aiming light source is a laser.

[0040] Aiming lens 450 on illumination system PCB 410 optically aligns with aiming LED 432 to collectively function as optical aiming system 560 (FIG. 5) in accordance with the illustrative embodiment of the present invention. More particularly, rear surface 554 of aiming lens 450 extends through first aperture 414 of illumination system PCB 410 and through an open portion of camera body 420 toward aiming LED 432 (disposed on image sensor PCB 430) .

[0041] Further details concerning aiming lens 450 and its operation are discussed below in conjunction with FIGs. 6-10.

[0042] FIG. 6 is a representation of the illumination field, field-of-view, and aiming illumination pattern as provided, respectively, by the illumination LEDs, the imaging system, and an optical aiming system in accordance with the illustrative embodiment of the present invention.

[0043] FIG. 6 depicts optical aiming system 560, which includes aiming LED 432 on image sensor PCB 430 and aiming lens 450 on illumination system PCB 410.

Illumination LEDs 412 are also shown. FIG. 6 also depicts image focusing lens 440 and image sensor 434, which define imaging system 662. As depicted in FIG. 6, image focusing lens 440 and aiming lens 450 are laterally offset from one another, creating parallax between the optical axes of the optical aiming system and the imaging system.

[0044] Illumination field IF is generated by illumination LEDs 412. A portion of this light is ultimately reflected off of the target {e.g. , barcode, etc.) to imaging system 662. In accordance with the invention, although optical axis OA_A of optical aiming system 560 is offset from optical axis OA of imaging system 662, aiming illumination pattern AIP is projected symmetrically within field-of-view FOV at the focal plane of the imaging system . In other words, optical axis OA_A of optical aiming system and optical axis OAj of the imager cross at the focal plane of the imaging system.

Furthermore, aiming illumination pattern AIP has a width, W_AIP, which is slightly narrower than field-of-view FOV. In some other embodiments, the width of the aiming illumination pattern AIP is substantially the same as field-of-view FOV. This is desirable in view of the quiet zones of bar codes and the reading operation. [0045] It is to be understood that field-of-view FOV and aiming illumination pattern AIP depicted in FIG. 6, 7, and 10 are rotated 90 degrees from the correct perspective. That is, they should appear in a plane that is actually parallel to illumination system PCB 410 and image sensor PCB 430 such that if FIG. 6 provided the correct perspective, the field of view, etc., would be viewed "end on." Since such a perspective provides no useful information, the perspective presented in the Figures is skewed by 90 degrees so that the field-of-view FOV and aiming illumination pattern AIP are viewed as if the image focusing lens 440 and aiming illumination LED 432 and lens 450 are parallel to the plane of the Figure and facing "into the page."

[0046] As depicted in FIG. 7, aiming illumination pattern AIP is at the center of field-of-view FOV at focal plane FP of imaging system 662. Aiming illumination pattern AIP is not centered in field-of-view FOV at other distances, such as in plane PI, which is at a distance less than the focal distance, or in plane P2, which is at a distance greater than the focal distance.

[0047] FIGs. 8A-8C, 9A-9B, and 10 depict further details concerning aiming lens 450. In accordance with the illustrative embodiment of the invention, the aiming lens provides at least the following functionality:

(1) It controls the horizontal width of the aiming illumination pattern (AIP) so that it is now wider, and preferably slightly narrower than, the horizontal extent of the field-of-view (FOV) of imaging system 662; and

(2) It refracts the optical axis (OA_A) of the aiming illumination so that it crosses the optical axis (OAi) of the imaging system at or very near to the focal plane of the imaging system.

In some additional embodiments, the aiming lens by virtue of its shape and/or location, provides one or both of the following additional functionality:

(3) Focuses light in the horizontal direction; and/or

(4) Collimates the aiming illumination in the vertical direction.

[0048] FIG. 8A depicts a side view of aiming lens 450 and shows the path of single-ray components of aiming light, as generated by aiming LED 432, through the aiming lens. Aiming lens 450 comprises polycarbonate or other materials that are highly transparent to visible light and readily moldable. In preferred embodiments, the emission angle of aiming LED 432 is 120 degrees. FIG. 11 depicts the emission pattern of an LED suitable for use as aiming LED 432. Without intervention, this broad emission pattern would cause the horizontal width of aiming illumination pattern AIP to far exceed the width of the imager's field-of-view FOV. [0049] Referring now to FIGs. 8A, 8B, and 10, the curved back surface 554 controls horizontal width W_AIP of aiming illumination pattern AIP. As previously noted, horizontal width W_AIP should be no more than the width of field-of-view FOV of the imaging system. Table 2 below shows a few examples of this relationship. The width Wpov of the imager's field-of-view FOV and the width W_AIP of aiming illumination pattern AIP are presented as "angles," since, in accordance with the invention, the aiming illumination pattern will be horizontally centered in the imager's field-of-view at the focal plane. The angles "a" and "β" are depicted in FIG. 10.

[0050] Table 2 depicts embodiments in which width W_AIP of aiming illumination pattern AIP, expressed as an angle and relative to the imager's field-of-view, ranges from 100 percent (i.e. , the same size) to 80 percent (i.e. , somewhat narrower) .

Assuming, for example, a horizontal angle of 40 degrees for the imager's field-of-view FOV, the width W_AIP of aiming illumination pattern AIP (expressed as an angle) is in a range from 40 degrees to 32 degrees. It is to be understood that in other

embodiments, the imager's field-of-view FOV can be greater than or less than 40 degree; that specific field-of-view is provided by way of illustration, not limitation.

Table 2: Comparison of Horizontal FOV Angle (Width) and

Horizontal Aiming Angle (Width)

[0051] It will be understood that given the perspective depicted in FIGs. 6, 7, and 10, variations in back surface 554 or front surface 552 of aiming lens 450 in a lateral (i.e. , left-right) direction will affect the "horizontal" attrributes of aiming illumination pattern AIP. Variations in these surfaces in a direction that is "into the page" will affect the "vertical" attributes of aiming illumination pattern AIP. The perspective of aiming lens 450 in FIG. 8A is the same as shown in FIGs. 6, 7, and 10. As a consequence, light rays depicted leaving surface 552 of aiming lens 450 in FIG. 8A define the lateral or horizontal extent of aiming illumination pattern AIP. The view of aiming lens 450 depicted in FIG. 9A corresponds to an "into-the-page" view of aiming lens 450 as seen in FIGs. 6, 7, and 10. As a consequence, light rays depicted leaving surface 552 of aiming lens 450 in FIG. 9A define the vertical extent of aiming illumination pattern AIP.

[0052] FIG. 8B depicts an enlargement of region AA shown in FIG. 8A. Region AA depicts a portion of back surface 554 of aiming lens 450 and the effect it has on single-ray component of light AL-1 emitted from aiming LED 432. In particular, ray AL-1, which propagates with a half-angle of 60 degrees (assuming that aiming LED 432 has an emission angle of 120 degrees), is refracted by angle 0 from its original direction of propagation via surface 554. After refraction, ray AL-2 proceeds along a new direction. Assuming, for example, that aiming illumination horizontal angle is 32 degrees (i.e. , embodiment 9 in Table 1), then 0 equals 44 degrees (i.e. , 60 -16) .

[0053] In the illustrative embodiment, the radius of curvature of back surface 554 of aiming lens 450 controls the amount by which beam AL-1 is refracted. Those skilled in the art will be able to determine the radius of curvature of back surface 554 as a function of the desired amount of refraction. It is to be understood that although it is preferable to curve the back surface of aiming lens 450, in some other

embodiments, the front surface of the aiming lens is curved (rather than the back surface) to control the horizontal width W_AIP of the aiming illumination pattern.

[0054] In embodiments in which the back surface 554 of aiming lens 450 controls the horizontal width of aiming light pattern AIP, it is desirable for back surface 554 to be in close proximity to the aiming LED, such as within 8 millimeters.

[0055] Referring now to FIGs. 8A, 8C, and 10, in the illustrative embodiment, front surface 552 of aiming lens 450 is linearly tapered or angled with respect to back surface 554. This arrangement, which effectively defines a prism, is dimensioned so that optical axis OA_A of the aiming illumination is refracted to cross optical axis OA of the imaging system at or very near to the focal plane of the imaging system. In some alternative, less-preferred embodiments, the "prism" (i.e. , the linearly tapered surface) is disposed at the back surface of aiming lens 450. This arrangement is not preferred because it requires a relatively greater angle of inclination (a greater prism apex angle) to create the required deviation in optical axis OA_A of the aiming illumination (compare the angle of incidence of ray AL-1 to ray AL-2) . [0056] FIG. 8C depicts an enlargement of region BB shown in FIG. 8A. Region BB depicts a portion of front surface 552 of aiming lens 450 and the effect it has on single-ray component of light Ai. -2 traveling through the aiming lens. In particular, ray AL-2 is refracted by angle yfrom its original direction of propagation via surface 552, which is angled by amount δ. After refraction, ray AL-3 proceeds along a new direction.

[0057] Angle γ by which ray AL-2 is refracted is the angular deviation required in optical axis OA_A of optical aiming system 560 so that it crosses optical axis OA of the imaging system at the focal plane of the imaging system. With reference to FIG. 10, it can be seen that deviation angle yean be determined by trigonometry knowing (1) the focal distance and (2) the offset between optical axis OA of the imaging system 662 and optical axis OA_A of optical aiming system 560 at the point of origin. In particular:

[1] y= tan^"1 (FD/X)

Where : FD= focal distance of imaging system 662;

X= the offset between the optical axes OA and OA_A at the location of aiming lens 450 and image focusing lens 440.

As will be appreciated by those skilled in the art, using Snell's Law at each interface, expressions for ray angle deviation can be determined. Those expressions can be rearranged to solve for prism apex angle δ.

[0058] FIG. 9A depicts an end view of aiming lens 450. As depicted in this Figure, surface 552 is curved . The curvature of surface 552 facilitates collimation of the aiming light in the "vertical" direction, as indicated by parallel rays AL-3. FIG. 9B depicts an enlargement of region CC shown in FIG. 9A, showing an angular deviation of ^ due to the curvature of surface 552.

[0059] With reference to both FIGs. 9A and 8A, surface 552 is therefore "curved" as well as being linearly tapered. From the perspective shown in FIG. 8A, surface 552 linearly tapers from left to right and is curved along the direction that is "into the page." From the perspective shown in FIG. 9A, surface 552 is curved from left to right and linearly tapers along the direction that is "into the page." Thus, surface 552 linearly tapers in a direction that is orthogonal to a direction in which surface 552 curves.

[0060] A minimum amount of clearance, such as at least about 10 millimeters, between aiming LED 432 and front surface 552 of aiming lens 450 is required in order to vertically collimate the aiming illumination emitted from an LED with an emission angle of 120 degrees.

[0061] Example. The following is a specific embodiment of an optical aiming system in accordance with the present teachings, wherein distances and angles are provided for parameters that are referenced in this specification.

Emission angle of aiming LED : 120 degrees

Distance Yl between aiming LED 432 and

back surface 554 of aiming lens 450: 4.5 millimeters

Distance Y2 between aiming LED 432 and

front surface 552 of aiming lens 450: 11.5 millimeters

Radius of curvature of back surface 554 of

aiming lens 450: 15 millimeters

Radius of curvature of front surface 552 of

aiming lens 450: 5 millimeters

Focal distance of imaging system 662: 130 millimeters

Distance between optical axis OA_A of

aiming system 560 and optical axis OAj of

imaging system 662: 7 millimeters

Deviation angle χ η optical axis OA_A of

aiming system 560 to cross optical axis OAj Of

imaging system 662 at the focal distance: 3.1 degrees

[0062] It is to be understood that the disclosure teaches just one example of the illustrative embodiment and that many variations of the invention can easily be devised by those skilled in the art after reading this disclosure and that the scope of the present invention is to be determined by the following claims.

Claims

What is claimed is:

1. An apparatus comprising an optical aiming system and image focusing lens, wherein the image focusing lens:

(A) is characterized by a field-of-view, a focal distance, and a first optical axis;

(B) receives light reflected from a target that is within the field of view; and wherein the optical aiming system comprises:

(A) a single light source for providing aiming illumination; and

(B) an aiming lens that projects the aiming illumination toward the target, wherein no aperture is interposed between the light source and the aiming lens, and further wherein the aiming lens is:

(i) laterally offset from the image focusing lens;

(ii) characterized by a second optical axis;

(iii) dimensioned and configured so that:

(a) the first optical axis and the second optical axis intersect at a focal plane located at the focal distance away from the image focusing lens;

(b) the aiming illumination is centered as an aiming illumination pattern within the field of view at the focal plane.

2. The apparatus of claim 1 wherein the aiming lens is further dimensioned and configured to collimate aiming illumination that is propagating in a vertical direction.

3. The apparatus of claim 1 wherein a width of the aiming illumination pattern is in a range of about 80 to 100 percent of a width of the field-of-view.

4. The apparatus of claim 1 wherein the aiming lens comprises a prism.

5. The apparatus of claim 4 wherein a front surface of the aiming lens linearly tapers along a first direction.

6. The apparatus of claim 5 wherein a back surface of the aiming lens is curved along the first direction.

7. The apparatus of claim 5 wherein the front surface of the aiming lens is curved along a direction orthogonal to the first direction to collimate aiming illumination in a vertical direction.

8. The apparatus of claim 6 wherein the aiming lens comprises polycarbonate.

9. The apparatus of claim 1 wherein the light source is an LED.

10. The apparatus of claim 9 wherein the LED has an emission angle of about 120 degrees.

11. The apparatus of claim 10 wherein a front surface of the aiming lens is configured to collimate aiming illumination that is propagating in a vertical direction and wherein a distance between the front surface and a point at which aiming illumination is emitted from the LED is at least about 10 millimeters.

12. The apparatus of claim 6 wherein a distance between the back surface and a point at which aiming illumination is emitted from the light source, which is an LED with an emission angle of about 120 degrees, is no more than about 8 millimeters.

13. The apparatus of claim 1 wherein the apparatus comprises a camera module, and wherein the aiming lens comprises mounting features for mounting the aiming lens to a portion of the camera module.

14. The apparatus of claim 13 wherein the portion of the camera module includes receiving features that receive the mounting features of the aiming lens, thereby locating the aiming lens in a specific and non-adjustable location within the camera module.

15. The apparatus of claim 1 wherein the apparatus is an optical image scanner and reading device, and wherein the optical image scanner and reading device include a camera module, and wherein the optical aiming system and image focusing lens are disposed in the camera module.

16. An apparatus comprising an optical aiming system and image focusing lens, wherein the image focusing lens:

(A) a single fixed position LED for providing aiming illumination; and

(B) a fixed position aiming lens that receives the aiming illumination at a first

curved surface and projects the aiming illumination, toward the target, from a second surface having a linear taper and along a second optical axis as an aiming illumination pattern, wherein no aperture is interposed between the LED and the aiming lens, and further wherein :

(i) the aiming lens is laterally offset from the image focusing lens;

(ii) the aiming lens comprises a prism, wherein the prism includes the second surface, and wherein the prism refracts the second optical axis so that it crosses the first optical axis at a focal plane located at the focal distance away from the image focusing lens; and

(iii) the first curved surface has a radius of curvature suitable for restricting a width of the aiming illumination pattern at the focal plane to a width that is no greater than a width of the field-of-view at the focal plane.

17. The apparatus of claim 16 and further wherein the second surface is curved along a direction that is orthogonal to the linear taper, wherein the curvature facilitates collimation of the aiming illumination in a vertical direction.

18. The apparatus of claim 17 wherein a first distance between the second surface and a point at which aiming illumination is emitted from the LED is at least about 10 millimeters and a second distance between the first surface and the point at which aiming illumination is emitted from the LED is no more than about 8 millimeters.

19. The apparatus of claim 16 wherein the apparatus comprises a camera module including an illumination system PCB, a camera body, and an image sensor PCB, wherein the illumination system PCB mounts to a front surface of the camera body and image sensor PCB mounts to a back surface of the camera body, and further wherein the aiming lens comprises mounting features that are received in a defined location on the illumination system PCB that places the aiming lens in optical communication with the LED, which is disposed on the image sensor PCB.