Optimized lighting system for vertical and horizontal slot scanners

Abstract

A slit scanner lighting system (10) for a convertible slit scanner assembly comprises a chassis (30) having an optical cavity (32) and a front aperture (34). The optical cavity (32) has an optical axis through the latter, with the optical axis being an axis along which light can be received by the chassis through the front aperture. The front aperture further has a first edge (40a) and a second edge (40b) opposite the first edge. A scanning window is configured to at least partially cover the front aperture of the chassis, and the scanning window has a normal axis orthogonal to a flat surface of the scanning window. A lighting element is disposed inside the optical cavity of the chassis. The lighting element is disposed near the first edge of the front aperture.The lighting element is configured to provide illumination along a lighting axis, in which the lighting axis is not parallel to the optical axis and is at an angle directed towards the second edge of the front aperture. Figure: 1.

Description

Title of the invention: Optimized lighting system for vertical and horizontal slit scanners. Background of the invention

[0001] Barcode readers and other scanning devices generally capture images within a given field of view (FOV). Barcode readers may be designed for use in different orientations depending on the environment. For example, some barcode readers may be implemented in a typically vertical orientation for use on countertops, kiosks, and other vertical scanning environments, and may also be used in a typically horizontal orientation for use in tabletop or tray environments. Typically, horizontal and vertical barcode readers have different design requirements due to the different fields of view. More specifically, in vertical orientations, the FOV is typically parallel to the table (i.e., perpendicular to the front face of the barcode reader).Conversely, in horizontal orientation, the FOV is tilted to scan barcodes on packaging in different orientations. Furthermore, each of the different FOVs in different orientations requires different lighting fields to scan an item or index.

[0002] These different design requirements sometimes necessitate different housing and component locations, as well as additional components such as printed circuit boards. The varying illumination requirements of the multiple FOVs typically increase system complexity by requiring additional light sources, additional electronics, and additional optics such as lenses. The increased number of parts and components required increases the number of potential failure points for a device, increases the cost of the device, and may necessitate a large housing that is not compatible with some scanning stations or platforms. Furthermore, some configurations may be susceptible to damage from liquids or other foreign matter that may inadvertently enter the device.

[0003] Therefore, there is a need for improved accessories having enhanced functionalities. Summary

[0004] According to a first aspect, a slit scanner lighting system is proposed, comprising a chassis having an optical cavity and a front opening. The optical cavity has an optical axis through it, with the optical axis being an axis the along which light can be received by the chassis through the front aperture. The front aperture has a first edge and a second edge opposite the first edge. A scanning window is configured to at least partially cover the front aperture of the chassis. The scanning window has a normal axis orthogonal to a flat surface of the scanning window. A lighting element is disposed inside the optical cavity of the chassis. The lighting element is disposed near the first edge of the front aperture. The lighting element is configured to provide illumination along a lighting axis, in which the lighting axis is not parallel to the optical axis and is at an angle directed toward the second edge of the front aperture.

[0005] In some examples, the lighting element is arranged at an angle of 30 to 60 degrees relative to the normal axis of the scanning window. In some configurations, the lighting element is arranged to provide illumination at an angle of incidence with the scanning window that results in 60% or more of radiation transmission. In other configurations, the lighting element is positioned recessed relative to the scanning window by a distance of between three and six centimeters.

[0006] In some examples, the illumination system for a slit scanner further includes an optical element operationally coupled to the illumination element. In some forms, the optical element is arranged (i) to receive illumination from the illumination element, and (ii) to provide illumination along the illumination axis. In some forms, the illumination element comprises six light-emitting diodes (LEDs) including both red and white LEDs.

[0007] In some examples, the lighting element comprises a plurality of lighting elements arranged in two groups, and further comprises a scan indicator disposed between the two groups. In some forms, the scan indicator is a light source that provides illumination following the successful scanning of an item by the illumination system for the slot scanner.

[0008] In some examples, the chassis further includes a flange arranged along the first edge of the chassis. In some forms, the flange is configured to at least partially obscure the lighting element from the scanning window.

[0009] In other examples, the illumination system for a slit scanner further includes an image sensor disposed in the optical cavity. In some forms, the sensor is arranged to receive an image through the scanning window, with the image sensor having an imaging field of view (FOV) along the optical axis. In some forms, the illumination system for the scanner further includes at least one reflecting mirror, at least partially disposed in the optical cavity. In some forms, the at least one reflecting mirror is configured to redirect the FOV of the image sensor through the scanning window. In shapes, the image sensor is a color image sensor.

[0010] In one embodiment, the lighting axis has an angle between 30 and 60 degrees relative to the normal axis of the scanning window.

[0011] In one embodiment, the lighting element comprises fewer than 6 LEDs.

[0012] In one embodiment, the lighting element comprises a plurality of LEDs.

[0013] In one embodiment, the lighting element is arranged to provide lighting with a uniformity ratio, defined by the maximum to minimum lux of a value less than 2 in the FOV between 5.08 and 20.32 cm (two and eight inches) of the scanning window.

[0014] In one embodiment, the image sensor is a color imaging camera.

[0015] In one embodiment, the two groups are spaced at least 3.81 cm (1.5 thumb).

[0016] In one embodiment, the two groups are configured to light independently and can (i) light simultaneously or (ii) light alternately. Brief description of several views of the drawings

[0017] The accompanying figures, in which the same reference numbers denote identical or functionally similar elements on all separate views, together with the detailed description below, are incorporated and form part of the specification and serve to further illustrate embodiments of the concepts which comprise the claimed invention, and to explain various principles and advantages of these embodiments.

[0018] [Fig. 1] The [Fig. 1] is a perspective front view of a digital industrial barcode reader assembly according to the present disclosure.

[0019] [Fig.2] The [Fig.2] is a rear perspective view of the digital industrial barcode reader assembly of the [Fig.1] according to this disclosure.

[0020] [Fig.3] The [Fig.3] is a side elevation sectional view of the digital industrial barcode reader assembly of Figures 1 and 2 coupled to a first adapter according to this disclosure.

[0021] [Fig.4] Fig.4 is a front perspective view of the digital industrial barcode reader assembly of Figures 1 to 3 coupled to a second adapter according to this disclosure.

[0022] [Fig.5] The [Fig.5] is a side elevation sectional view of the digital industrial barcode reader assembly of Figures 1 to 4 coupled to the second adapter according to this disclosure.

[0023] [Fig.6A] The [Fig.6A] is a first lateral perspective cross-sectional view of the digital industrial barcode reader assembly and a lighting assembly with imaging and lighting fields of view.

[0024] [Fig.6B] The [Fig.6B] is a second lateral perspective cross-sectional view of the digital industrial barcode reader assembly and a lighting assembly with imaging and lighting fields of view.

[0025] [Fig.6C] The [Fig.6C] is a front perspective view of the entire digital industrial barcode reader assembly with imaging and lighting fields of view.

[0026] [Fig.6D] The [Fig.6D] is a top cross-sectional perspective view of the entire digital industrial barcode reader assembly with imaging and lighting fields of view.

[0027] [Fig.7] Fig.7 is an enlarged view of a lighting element such as an LED, and of a mounting notch in an optical cavity of the digital industrial barcode reader of figures 1 to 6D.

[0028] [Fig.8A] The [Fig.8A] is a simulated lighting image provided by a lighting set supplied by the digital industrial barcode reader set of Figures 1 to 6D, at a distance of 10.16 cm (four inches).

[0029] [Fig.8B] The [Fig.8B] is a simulated lighting image provided by a lighting set supplied by the digital industrial barcode reader set of Figures 1 to 6D, at a distance of 20.32 cm (eight inches).

[0030] Those skilled in the art will note that the elements in the figures are illustrated for the sake of simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention.

[0031] The components of the apparatus and the method have been represented, where appropriate, by conventional symbols in the drawings, representing only those specific details relevant to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be more clearly understood by those skilled in the art by referring to the description. Detailed description

[0032] With reference to the figures, reference numeral 10 generally denotes a convertible slot scanner assembly for taking at least one image of an object appearing in a field of view (FOV). The convertible slot scanner assembly 10 comprises a printed circuit board 11, an image sensor 12, a control unit 16, an image decoder 20, at least one interconnect 22, a chassis body 30, a first window 60, and in some examples, a housing 80. While not illustrated in Figures 1 and 2, the slot scanner assembly 10 further includes a lighting assembly 24, the illustration of which begins in [Fig.3].

[0033] The chassis 30 comprises a front side 30a, a rear side 30b, an upper side 30c, a front face 30d at the level of the front side 30a, an optical cavity 32, and an aperture 34 formed on the front side 30a. In some examples, the chassis 30 may be segmented into quadrants, and may include a front quadrant 31a, an upper quadrant 31b, and so on. It should be noted that while the remaining quadrants are not assigned reference numbers, each quadrant may represent approximately one-quarter of the relative dimension (e.g., a thickness or height dimension) of the chassis 30. Furthermore, the optical cavity 32 may include and / or define a mirror support surface 36. The terms "front," "upper," and "rear" all refer to a vertical configuration of the scanning assembly 10.A person skilled in the art should recognize the references and terms in relation to the whole in a horizontal orientation, as further described here in relation to the illustrative figures.

[0034] In general, the chassis 30 is configured to house the entire opto-mechanical unit, such as the image sensor 12, the control unit 16, the image decoder 20, the imaging assembly 24 and the interconnect or interconnections 22. In other words, in the illustrated examples, the image sensor 12, the control unit 16, the image decoder 20, the lighting assembly and the interconnect or interconnections 22 are all advantageously arranged on the printed circuit board 11, which is positioned at or near the upper side 30c and / or the upper quadrant 31b of the chassis. In particular, by positioning these components in the upper region of the chassis, they are less likely to be damaged by liquids or other unwanted objects such as dirt, dust, grime and the like when the convertible slot scanner assembly 10 is positioned in any of its possible orientations or configurations.Furthermore, by using the chassis 30 to mount the opto-mechanical unit separately from the housing 80, the assembly 10 can be used in terminal applications where the assembly 10 does not require an additional housing, thus reducing costs. Having the illumination assembly 24 positioned on the circuit 11 near or at the top side of the 30 allows the illumination assembly to provide uniform illumination over multiple fields of view (FOV) of the image sensor 12.

[0035] In some examples, the chassis 30 may further include a flange 38 which at least partially surrounds the opening 34. In examples in which the system includes the housing 80, the flange 38 may serve as a mounting mechanism and / or a sealing gasket to make the entire perimeter of the housing 80 watertight. The flange 38 can be positioned at least along a first edge 40a of the opening 34. The flange 38 positioned along the first edge 40a is configured to at least partially obscure a lighting element of the scanning window. Consequently, the flange 38 can prevent a user from directly viewing the lighting elements of the lighting assembly 24, providing more comfortable operation of the scanning assembly 10 for a user of the scanning assembly 10. The flange 38 can also be used as a mounting feature for original equipment manufacturer (OEM) applications, such as in a scanning terminal. The flange 38 may include mounting holes to provide a means of mounting the scanning assembly 10 on a terminal or point-of-sale system.The system 10 may further include a sealing element such as a gasket (not shown) to seal the housing 80 and to create a dustproof seal and / or an electrostatic discharge seal. The chassis 30 can be constructed from any number of materials, such as, for example, metals and / or polymers.

[0036] In the illustrated example, the opening 34 further defines a support lip or recess 35. In addition, the flange 38 may include any number of mounting features 37 (e.g., holes) to accept mounting the chassis 30 in horizontal, vertical, and / or terminal applications. However, in other examples (not illustrated), the flange may not be supported by the chassis 30, but rather by components used to mount the chassis in horizontal, vertical, and / or terminal applications.

[0037] The optical cavity 32 is a generally hollow region that allows light to pass to the image sensor 12 and also allows light to pass from the illumination assembly 24 through the aperture 34 to one or more FOVs of the image sensor 12. A reflecting mirror 42 is disposed on the mirror support surface 36 inside the optical cavity 32 to redirect the FOV of the image sensor 12. The illustrated examples include a single reflecting mirror 42 which, when combined with the relatively high positioning of the image sensor 12, advantageously increases the length of the optical path, thus resulting in a large FOV at the first window 60.Furthermore, such a configuration allows the FOV to grow gradually, thus maintaining resolution compared to previous designs with rapidly growing FOVs that quickly lose resolution outside the optical cavity 32. In some examples, the reflecting mirror 42 may include length tolerances to accommodate pointing errors of the optical sensor 12. Additionally, it should be noted that any number of reflecting mirrors 42 can be used. In some examples, the reflecting mirror 42 is positioned to bring a central axis. the FOV to be angled by a value less than approximately 20° relative to a plane perpendicular to the front face 30d of the chassis 30. Other examples are possible.

[0038] The chassis 30 includes a mounting portion 39 (for example, a generally flat surface) that houses the printed circuit board 11 by attaching the printed circuit board 11 to it via any number of suitable approaches. In some examples, only one printed circuit board 11 is provided in the convertible slot scanner assembly 10, which can advantageously reduce component costs, reduce the overall number of interconnects, and increase overall reliability. The image sensor 12, the control unit 16, the image decoder 20, and / or the interconnect 22 can all be directly and / or operationally coupled to the printed circuit board 11 via any number of suitable approaches.

[0039] The image sensor 12 is configured to capture an image frame appearing in a field of view (FOV). The image sensor 12 can comprise any number of photosensitive elements. In some examples, the image sensor 12 may have a resolution of 2 megapixels, although other examples are possible. The image decoder 20 is coupled, via communication, to the image sensor 12 and is configured to decode a barcode captured on an image by the image sensor 12. In some examples, only the image sensor 12 is coupled, via communication, to the decoder 20 and is used to process the images to decode indices.

[0040] As mentioned previously, in some examples, the interconnection 22 is located on the chassis 30. In the illustrated examples, the interconnection is located on the rear side 30b of the chassis 30. As shown in Figures 5 to 8, the interconnection 22 is oriented downwards, which means that the cables 9 connected to it can be routed downwards. Consequently, the cable 9 can be disposed of within the volume or footprint of the chassis 30. Furthermore, this orientation helps to prevent the entry of splashes and / or drops of fluid into the interconnection 22 in both vertical and horizontal configurations of the chassis 30.As illustrated in Figures 2 and 5, any number of different interconnects can be used, such as a main product cable (e.g., an RJ45 / RS32 cable), a cable used for a point-of-sale interface if the assembly is used to accommodate another scanner (e.g., a portable mini slot scanner), and / or a PCB barrel jack power cable that can be used if an auxiliary scanner is planned. Other examples are possible.

[0041] The scanner assembly 10 further includes a lighting assembly 24 which can be directly and / or operationally coupled with the circuit board printed 11 via any number of suitable approaches. Therefore, the lighting assembly 24 is also positioned near the first edge 40a, at or near the upper side 30c of the chassis 30. In some examples (not shown), the lighting assembly 24 can be operationally coupled with a second, separate printed circuit board, which can also be positioned at or near an upper region of the chassis 30. While shown as being in the optical cavity 32, the lighting assembly 24 can be positioned in a separate lighting cavity from the chassis 30 that is separated (i.e., positioned at a distance) and at least partially isolated from the optical cavity 32.

[0042] In these examples, the lighting assembly 24 may be in the form of an offset lighting assembly. The lighting assembly 24 may comprise any number of light-emitting diodes (LEDs) 25, and other optical elements such as a light guide, lenses, mirrors, etc., for evenly distributing the emitted light. In some examples, the LEDs 25 may be Oslon lighting LEDs that have an intensity of approximately 70% over the desired illumination angle (e.g., approximately 60°). Other examples are possible. As with the FOV, the light supplied by the lighting assembly 24 exits through the first window 60 and is used to illuminate the FOV during scanning. In some examples, the lighting assembly 24 can be tilted downwards relative to the front face 30d of the chassis 30 in order to reduce and / or eliminate glare in the vertical orientation.

[0043] The window 60 is generally supported by the frame 30 and is configured to allow light to pass between a product scanning region and the cavity 32 of the frame 30. The first window 60 is generally positioned on the front side 30a and in the front quadrant 31a of the frame 30. More specifically, in the illustrated example, the window 60 is configured to be positioned on the rim or recess 35 of the frame 30. In other examples, the window 60 may simply be configured to at least partially cover the opening 34 of the frame 30 via any number of suitable approaches. In some examples, the first window 60 is configured to be angled at a value less than approximately 15° from a plane formed by the front face 30d of the frame 30.In some examples, the window 60 is configured to protrude from the flange 38 so that the window 60 can be positioned flush with a front bevel of a terminal (not shown) when mounted on the latter. In other examples, the window 60 is configured to be generally flush with the flange 38 when positioned in (or covering) the opening 34 of the frame 30. Therefore, the assembly... 10 can be used in terminal applications that do not include a recessed window that can accumulate debris.

[0044] With reference to Figures 3 to 9, the housing 80 may include a housing cavity dimensioned to at least partially accommodate the chassis 30. The housing 80 may be approximately 5.4" high and approximately 6.0" wide. The housing 80 further includes an outer surface 74 which, in some examples, may have a profile that generally tapers gradually when viewed from the first end 74a to its second end 74b. As illustrated in [Fig. 5], the second end 74b of the housing 80 may include openings 76 that are dimensioned and positioned to accommodate the interconnects 22 arranged on the printed circuit board 11. In addition, the second end 74b of the housing 80 may include any number of cable guide elements or guide grooves 77 that are cut and dimensioned to receive cables 9 that are inserted and / or coupled with the interconnects 22.In some examples (not shown), the guide grooves 77 may further include fasteners or fixing features for securing the cable 9.

[0045] The housing 80 can be positioned in a first horizontal configuration ([Fig. 3]) in which the first window 60 is generally horizontal, and in a second vertical configuration ([Fig. 4]) in which the first window 60 is generally vertical. More specifically, the housing 80 can be operationally coupled with one or more adapters 70 and 84 to selectively position the slot scanner assembly 10 in horizontal and vertical configurations, respectively. In horizontal configurations, the slot scanner assembly 10 can be positioned in a counter 8 ([Fig. 3]) where the scanner assembly 10 can be part of a conveyor or similar checkout environment. In vertical configurations, the slot scanner assembly 10 can be used in kiosks and / or counter environments.

[0046] With reference to [Fig. 3], the adapter 70 is used to position the slot scanner assembly 10 in the horizontal configuration and includes a tray 72 comprising a tray opening 74 and a second window 62. In some examples, the first adapter 70 may further include a tank 78. As with the frame 30, the tray opening 74 further defines a support lip or recess 75. The tray 72 may be supported by the housing 80, the flange 38 of the frame 30, and / or the tank 78. In some examples, the tray 72 may simply rest on the top of the housing 80, and in other examples, the tray 72 may be operationally coupled to the housing. In any of these examples, the tray 72 may be removed from the assembly 10 for cleaning and / or inspection. while the housing 80 can be held in the horizontal position. In some examples, the plate 72 can be keyed so that it detects the coupling with the assembly 10.

[0047] The second window 62 is generally supported by the platform 72 and is configured to allow light to pass from the product scanning area, through the second window 62, through the first window 60, and into the cavity 32 of the frame 30. The second window 62 may be made of a harder material than the first window 60, such as sapphire and / or glass with a diamond-like carbon coating that can resist damage from scratches and scuffs when items (e.g., products) slide over it during the item scanning process. In some examples, the second window 62 may have a smaller surface area than the first window 60.More specifically, the first window 60 may have a larger surface area to support a wider field of view for vertical and terminal embodiments, while the second window 62 may have a smaller surface area, which limits or reduces the size of the FOV because harder materials, such as sapphire, can be more expensive, and such a reduced surface area can lower costs. In some examples, the imaging FOV can be used to detect the presence of the tray 72, and when coupled with a sensor such as an accelerometer, can prevent the scanner from operating when the tray 72 is not seen in the FOV. In some examples, a barcode or other symbol (not shown) may be placed on an underside of the tray 72 that may be within the FOV of the first window 60. Such a symbol can be used to help the device 10 recognize the presence of the tray 72.

[0048] In the illustrated example, the second window 62 is configured to be positioned on the edge or recess 75 of the tray 72. In other examples, the second window 62 can be configured to cover, at least partially, the opening 74 of the tray 72 via any number of suitable approaches. In the illustrated examples, the second window 62 is configured to be generally flush with the tray 72 when it is positioned in (or covering) the opening 74 of the tray 72. Consequently, the items to be scanned can slide across these surfaces without being bumped or jostled. The tray 72 may further include a direction indicator (not shown) to provide a user with a visual indication of the scanning direction.

[0049] In some examples, the tank 78 has a tank cavity dimensioned to house, at least partially, the housing 80. In the illustrated example, the tank 78 includes a flange 81 that rests on the counter 8. Consequently, the counter 8 is configured to support the weight of the tank 78 as well as the components arranged inside it. The tank 78 may further include any number of centering arms. 82, which extend into the tank cavity. The tank 78 can be sized to fit into standard 6” x 6” countertop openings for horizontal slot mini scanners. The centering arms 82 can be used to center the housing 80 in the tank cavity, due to the smaller size of the housing (e.g., approximately 5.4” x 6”). Therefore, the centering arms 82 can be used to hold smaller scanning assemblies. In some examples, the centering arms 82 can be made from a resilient and / or flexible material to allow for the arrangement of different housings within the tank cavity. Other examples are possible. In other examples, the tank 78 can be configured to engage and couple with the flange 38 of the chassis 30.

[0050] Advantageously, by positioning the interconnections 22 at the upper side 30c of the chassis 30, the cable 9 can simply be angled downwards into the volume or footprint below the scanner assembly 10. For this reason, the cable 9 can remain connected during the installation and removal of the scanner assembly 10, and the scanner assembly 10 does not need to be bent or repositioned during installation.

[0051] With reference to Figures 4 and 5, the second adapter 84 is used to position the slot scanner assembly 10 in the vertical configuration and includes an external bevel 86 or annular element. The external bevel 86 is configured to engage at least one of the housing 80 or the flange 38 of the frame 30. In some examples, the external bevel 86 may include teeth (not shown) that can be inserted into the mounting features 37 formed on the flange 38 of the frame 30. For this reason, in the illustrated example, the external bevel 86 can be snapped onto the frame 30 and can retain the first window 60 and can protrude outwards from the first window 60 to form a recessed region 87.

[0052] Advantageously, by positioning the interconnections 22 at the upper side 30c of the chassis 30, the cable 9 can simply fall downwards into the volume or footprint below the scanner assembly 10, thus reducing the overall footprint of the scanner assembly 10.

[0053] As noted previously, the scanner assembly 10 can also be used in terminal environments. By removing the external bevel 84 and / or the housing 80, the mounting features 37 can be used to attach to a terminal housing (not shown). In these examples, the first window 60 can typically be parallel to the terminal housing to provide a wide FOV. By removing these components, the assembly 10 is less expensive and occupies less space inside the terminal. Again, by positioning the interconnects 22 at the top side 30c of the chassis 30, the cable 9 can simply drop down into the volume or the footprint below scanner assembly 10, thus reducing the overall footprint of scanner assembly 10.

[0054] Thus configured, the scanner assembly 10 can be easily converted for use in horizontal or vertical environments. Vertically or horizontally oriented environments are further described in US patent application 16 / 713,252.

[0055] In the examples, the illumination assembly 24 is configured to provide off-axis illumination at one or more FOVs of the image sensor 12 of the scanner assembly 10. Figures 6A to 6D depict the off-axis illumination assembly 24 described herein. The illumination assembly 24 is arranged in the optical cavity 60 near the first edge 40a of the frame 30. The illumination assembly 24 is arranged so that the illumination elements, in the form of LEDs 25, are positioned at a distance from the window 60. The window 60 can be referred to herein as a scanning window through which an index object can be scanned. The LEDs 25 are positioned at a distance from the window 60 to allow illumination of one or more FOVs of the image sensor 12 by the window 60. The LEDs 25 can be positioned at a distance of less than 10 cm, less than 6 cm, or less than 3 cm from the window 60.In some examples, the 25 LEDs are arranged between 2 and 6 cm inclusive or between 3 and 6 cm from the window 60.

[0056] Lighting elements, such as the LEDs 25, of the lighting assembly 24, are arranged at an angle to provide illumination along a lighting axis B of the lighting assembly 24. The lighting axis B is not parallel to an optical axis A of the scanner assembly 10. The optical axis A is normal to the window 60 and is also an axis along which propagating light can be directed to the image sensor 12. The lighting axis B is intentionally offset from the optical axis A in order to reduce the amount of light from the lighting assembly 24 reflected from the window 60 and subsequently detected by the image sensor 12. Furthermore, the lighting assembly 24 is intentionally positioned near the first edge 40a, at a distance from the window 60 and at an offset angle to the image axis A to provide a substantially uniform distribution of light to one or more FOVs of the image sensor 12.For example, the angle between the optical axis A and the illumination axis B, illustrated as angle 0AB, can be 40° or 50°. In some embodiments, the angle between the optical axis A and the illumination axis B can be less than 30°, less than 40°, less than 50°, less than 60°, less than 70°, from 10° to 20°, from 20° to 40°, from 20° to 50°, or from 30° to 60°. In some examples, the illumination assembly 24 and / or the LEDs 25 can be positioned at an angle such that it provides illumination along the illumination axis B. In other examples, the optics (e.g., lenses, mirrors, diffraction elements, etc.) can be coupled. optically, with LEDs 25 directing the illumination along the illumination axis B. In some examples, the LEDs are arranged to provide radiation at an angle of incidence with the window 60 that results in a light transmission value greater than 50% or greater than 60% through the window 60. The desired amount of light transmission can be achieved with the illumination axis B at an angle between 30° and 60° to the optical axis A. In some implementations, the illumination assembly 24 provides illumination that is 3° to 5° wider or between 4° and 10° wider than a FOV of the image sensor 12 of the assembly 10. The distance between the LEDs 25 and the window 60 can be determined based on the desired angle of incidence of the radiation from the window 60 and the desired amount of transmitted radiation.For example, the LEDs 256 can be arranged in the optical cavity 32, in a recessed position relative to the window 60 which is large enough to allow an angle of incidence of illumination between 30° and 50° with the normal axis of the window.

[0057] The LEDs 25 may comprise both red LEDs 25a and white LEDs 25b. The red LEDs 25a may provide red illumination to a FOV of a monochrome imaging device, and the white LEDs 25b may provide white light to a FOV of a color vision camera. Thus, the image sensor 12 may comprise both a red monochrome barcode scanning sensor and a color camera or color sensor, each having its respective FOV. The FOVs of the two image sensors may overlap fully or partially. Therefore, the illumination assembly 24 may provide simultaneous illumination of both FOVs of a monochrome barcode scanning sensor and a color image sensor for scanning in both vertical and horizontal configurations.In some examples, all 25 LEDs can be white LEDs if the image sensor 12 only includes a color vision camera, or all 25 LEDs can be red or monochromatic LEDs if the image sensor 12 only includes a monochromatic barcode scanning sensor.

[0058] In embodiments of the assembly 10 which includes a color vision camera, the chassis 30 may further include a camera aperture 14 in the optical cavity 32. A color camera may be disposed behind the camera aperture 14 opposite the first window 60. Light may propagate through the first window 60 and through the camera aperture 14 where the color camera then detects the light.

[0059] Figures 6C and 6D represent a model imaging assembly 24 that uses six LEDs 25 positioned in the optical cavity 32 in two separate groups of three LEDs 25 each. Each group of LEDs 25 provides illumination along a respective illumination axis B. In some examples, the illumination assembly may use less six LEDs 25 to provide substantially uniform illumination over one or more FOVs of the image sensor 12. The nearest LEDs of the two groups of LEDs 25 may be spaced 2.54 cm (1 inch), 5.08 cm (2 inches), 7.62 cm (3 inches), between 2.54 cm and 12.7 cm (1 and 5 inches), at least 2.54 cm (1 inch), at least 3.81 cm (1.5 inches) or at least 5.08 cm (2 inches). The imaging assembly 24 can use any number of a plurality of LEDs 25 which depends on the voltage and / or current limitations of a power supply that provides power to the assembly 10. The imaging assembly 24 can use both white and red LEDs 25b and 25a respectively, to perform both barcode scanning and image scanning using a single assembly 10.For example, the red LEDs 25a can be used to provide red light for barcode scanning during one scan cycle, and the white LEDs 25b can provide white light in a subsequent scan cycle for imaging an object. In some examples, each group of LEDs 25 might use only one LED. Therefore, the lighting assembly 24 described can significantly reduce the number of elements required to provide illumination at multiple FOVs. In some examples, each group of LEDs 25 might consist of only one LED.

[0060] A scan indicator light guide 26 is disposed between the two groups of LEDs 25. The scan indicator light guide 26 can be seen through the first window 60 and the second window 62 when the scanner assembly 10 is used in the horizontal configuration. The illumination cavity 33 can advantageously allow the use of a parallel window 60 that is flush or nearly flush with the first end 64a of the outer surface 64 of the housing 70, thus allowing the scanner assembly 10 to be used in horizontal and terminal configurations. A light source, not shown, can supply light to the scan indicator light guide 26, which can direct the illumination from the source and emit the illumination through the first and second windows 60 and 62. The scan indicator light guide 26 can illuminate and provide a visual signal to a user that a scan has been performed.In some examples, the radiation supplied to the scan indicator light duct may be white light or another color of light to indicate that a scan has been performed.

[0061] In some examples, the first edge 40a may protrude at least partially into the opening 34 to block the LED 25 from a user's view. Blocking the LED 25 from view allows for more comfortable operation of the scanner assembly 10. In some examples, the first edge 40a prevents the illumination from directly entering a user's eyes at distances of 1 ft, 2 ft, 3 ft, between 1 and 2 ft, between 2 and 3 ft, or between 1 and 4 ft from the assembly 10. The first edge 40a may protrude to a distance that prevents the light from entering a user's eyes. at the location installed at the fifth percentile, which is approximately 35.56 ± 5.08 cm (14 ± 2 inches) above the bottom of the 10-scan assembly, and 50.8 ± 5.08 cm (20 ± 2 inches) opposite the first 60-window of the 10-scan assembly.

[0062] Figure 7 represents a section ridge 54 in the optical cavity 32 which is at Proximity to LEDs 25. The cutting edge 54 reduces the FOV of illumination of LEDs 25 by blocking the light they provide. The cutting edge 54 prevents the illumination from LEDs 25 from reflecting off the internal surfaces of the optical cavity 32 near the second edge 40b. Light reflected off the internal surfaces of the optical cavity 32 can reach the image sensor 12, causing image noise that can reduce the efficiency of object and scan indices during the operation of the scanner assembly 10. Therefore, the cutting edge 54 provides a measure of decreasing signal noise during scans.

[0063] Figures 6A to 6D illustrate the imaging FOV 56 of the image sensor 12. In addition, the illumination FOV 58 is shown overlapping the imaging FOV 56. Figures 6A and 6B represent a vertical component of the FOVs 56 and 58, while Figures 6C and 6D represent a horizontal component of each of the FOVs 56 and 58. The illumination FOV 58 provides substantially uniform illumination over the imaging FOV 56 for a plurality of distances from the window 60 along the optical axis A. As previously described, the illumination FOV 58 is configured to provide illumination only to the window 60 and to reduce the illumination that can be reflected from the internal surfaces of the optical cavity 32. As illustrated in [Fig. 6B], the illumination FOV 58 may have an asymmetrical FOV around the illumination axis. For example, the 58 lighting FOV may have an upper FOV angle of 0AB and a lower FOV angle of 0b where 0AB and 0b are not equal.For example, the upper FOV angle can be 40°, while the lower FOV angle can be 28° with respect to the illumination axis B. The ridge 54 can cut the illumination to provide the asymmetric illumination FOV 58, or other elements can be used to form the illumination FOV 58 (e.g., lenses, apertures, mirrors, etc.). Furthermore, as shown in Figures 6C and 6D, the illumination FOV 58 can have a horizontal dimension that is between 2° and 5° wider, between 4° and 8° wider, or between 5° and 10° wider than the imaging FOV 58.

[0064] Figures 8A and 8B are simulated illumination maps representing substantially uniform illumination at 10.16 cm and 20.32 cm (4 and 8 inches) opposite window 60, respectively. [Fig. 8A] is an image that represents a simulation of the light distribution at 10.16 cm (four inches) from window 60 in a vertically oriented configuration, as described herein, and [Fig. 8B] is a simulation of the light distribution of the same imaging set configured at a distance of 20.32 cm (eight inches) from window 60. Both images represent the imaging FOV 56 of image sensor 12. A ratio of maximum brightness pixel value to minimum brightness pixel value is used here to evaluate how uniform the light distribution is over the imaging FOV 56. For both the 10.16 cm and 20.32 cm (four and eight inches) values ​​relative to the 60 window, the maximum brightness to minimum ratio was found to be approximately 2. Therefore, the darkest pixel has a brightness of about 50% of the brightest pixel. In examples, substantially uniform illumination may have a maximum-to-minimum brightness ratio between 1.8 and 2.2, between 1.5 and 2.5, less than 2, or less than 3. In examples, illumination uniformity may be determined by taking the maximum and minimum brightness values ​​at the cross-sections of the imaging FOV 56 and normalizing the difference to the maximum brightness value, as defined by: tr _ Smax-Smin Smax where Smax and Smin are lux values ​​(i.e., W / m²). For example, a maximum lux of 45 W / m² and a minimum lux of 20 W / m² result in a uniformity of 0.55. This is also an example of a maximum-to-minimum uniformity ratio slightly greater than 2. The substantially uniform light distribution is achieved by placing the LEDs 25 in a recessed position opposite the window 60 and having an illumination axis B that is not parallel to, and is offset from, the imaging axis A. Typical lighting systems and devices are unable to provide substantially uniform illumination in a similar manner over one or more FOVs within a range of distances in a scanning set.

[0065] While described herein as LEDs 25, the lighting assembly 24 may comprise one or more lighting elements. For example, the lighting assembly 24 may comprise laser diodes, blackbody radiation sources, fluorescent elements, and / or flash bulbs. Furthermore, the lighting assembly 24 may comprise additional optical elements coupled to the LEDs 25 to receive illumination from the LEDs 25. The additional optical elements are physically configured to provide illumination along the illumination axis B. For example, the LEDs 25 may be lensed LEDs 25, or one or more external lenses may receive light from the LEDs 25 and provide illumination along the illumination axis B. Additionally, mirrors may redirect the light from the LEDs 25 and provide illumination along the optical axis B.

[0066] The scanner assembly 10 can include any number of additional components to assist its operation. For example, the scanner assembly 10 can include any number of interface elements 90 with which a user can interact. The interface element 90 can be in the form of The shape of a button or buttons 92, a lighting element or elements of the lighting assembly 24, a sound-generating device 96 (e.g., a loudspeaker or horn), and the like. Other examples are possible. In general, the interface elements 90 can be positioned at or near the flange 38 and / or part of the housing 80.

[0067] The interface elements 90 can be engaged, visible, or audible from a side facing outwards from the housing. For example, the button or buttons 92 can be positioned along the flange 38 of the chassis 30 and can be physically engaged by means of the first adapter 70 and the second adapter 84. The buttons 92 can be in the form of physical buttons or capacitive buttons. In examples using physical buttons, the first and second adapters 70, 84, and more specifically the tray 72 and the external bevel 86, can include openings 72a, 86a through which the button or buttons 92 can protrude to be engaged by a user. In examples using capacitive buttons, the first and second adapters 70, 84 can include an indicator (not shown) for where the user must press in order to engage the button 92.In some horizontal implementations, it may be desirable to position the buttons 92 below the tray 72 to prevent a user from inadvertently pressing the button 92. Therefore, the tray 72 may include a hollow cavity to house such a button 92.

[0068] As previously noted, a lighting element may include an indicator light guide coupled to the lighting assembly 24, which can be observed through the first window 60 and the second window 62 when the scanner assembly 10 is used in the horizontal configuration. A separate lighting cavity may advantageously allow the use of a parallel window 60 that is flush or nearly flush with the first end 64a of the outer surface 64 of the housing 80, thus allowing the scanner assembly 10 to be used in both horizontal and terminal configurations.

[0069] The sound generation device 96 can be positioned near and operationally coupled with the printed circuit board 11 and can be arranged on the flange 38 of the chassis 30. The flange 38 can include any number of speaker ports 96A to allow sound to travel through the flange 38. Similarly, the tray 72 and the external bevel 86 can include openings 72b, 86b which allow sound emitted by the sound generation device 96 to pass through them.

[0070] Thus configured, the scanner assembly 10 can be lower in cost due to the use of shared parts and can easily be functionally adaptable if necessary. By using a single scanner and a single lighting assembly for With multiple orientations, the total number of product configurations can be reduced, including additional circuitry and optics for the lighting assembly. The scanner assembly can be easily implemented in kiosks and self-checkouts, and can be readily reused in stores even if they wish to change the type of scanner they use. Furthermore, by using a shared window for both configurations, the scanner assembly is more easily convertible and maintains the seal for the optical cavity, even if the configuration is switched. The shared window is the only window for vertical orientations and is held in place by the front bevel (which can be snapped into place). The shared window becomes the internal window when the scanner assembly is used in the horizontal configuration.

[0071] In the preceding specification, specific embodiments were described. However, those skilled in the art note that various modifications and changes can be made without departing from the scope of protection of the invention presented in the claims below. Therefore, the specification and figures should be considered in an illustrative rather than restrictive sense, and all such modifications are intended to be included within the scope of protection of this specification. Furthermore, the described embodiments / examples / implementations should not be interpreted as mutually exclusive, but rather should be understood as potentially being combined if such combinations are permissible in any way.In other words, any one of the features described in any of the previously mentioned embodiments / examples / implementations can be included in any of the other previously mentioned embodiments / examples / implementations.

[0072] Benefits, advantages, solutions to problems, and any elements that may cause a benefit, advantage, or solution to occur or become more pronounced, shall not be construed as a critical, required, or essential feature or element of any or all of the claims. The invention is defined solely by the attached claims, including any amendments made during the processing of this application, and all equivalents of these claims as granted.

[0073] Furthermore, in this document, relational terms such as first and second, superior and inferior, and the like may be used only to distinguish one entity or action from another without necessarily requiring or implying a true relationship or order between such entities or actions. The terms "includes," "comprising," "has," "having," "includes," "containing," "containing," or any variant thereof, are included for to cover a non-exclusive inclusion, such that a process, method, article, or device that includes, has, includes, or contains a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or device. An element preceded by "includes ... a", "has ... a", "includes ... a", or "contains ... a" does not, without further constraints, preclude the existence of additional identical elements within the process, method, article, or device that includes, has, includes, or contains the element.The terms "substantially," "essentially," "approximately," "about," or any of their other variations, are defined as being close to the understanding of a person skilled in the art. In one non-limiting embodiment, the term is defined as being within 10%, in one embodiment within 5%, in another embodiment within 1%, and in yet another embodiment within 0.5%. The term "coupled," as used here, is defined as being connected, although not necessarily directly and not necessarily mechanically. A device or structure that is "configured" in a certain way is configured at least in that way, but may also be configured in ways not listed.

[0074] It should be noted that certain embodiments may consist of one or more generic or specialized processors (or "processing devices") such as microprocessors, digital signal processors, custom 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, together with certain processorless circuits, some, most, or all of the functions of the process and / or apparatus described herein. Alternatively, some or all of the functions may 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 certain combinations of certain functions are implemented as custom logic.Of course, a combination of the two approaches can be used.

[0075] Furthermore, an embodiment can be implemented in the form of a computer-readable storage medium having computer-readable code stored on it for programming a computer (for example, including a processor) to perform a method as described and claimed herein. Examples of such computer-readable storage media include, but are not limited to, a disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (read-only memory), a PROM (programmable read-only memory), and an EPROM. (reprogrammable read-only memory), an EEPROM (electrically programmable erasable read-only memory), and Flash memory. Furthermore, it is expected that a person skilled in the art, despite potentially significant effort and numerous design choices driven, for example, by available time, current technology, and economic considerations, when guided by the concepts and principles described herein, will be able to easily generate such software and program instructions and ICs with minimal experimentation.

[0076] The abbreviated disclosure is provided to enable the reader to quickly determine the nature of the technical disclosure. It is submitted with the understanding that it is not to be used to interpret or limit the scope of protection or the meaning of the claims. In addition, in the preceding detailed description, it can be seen that different features are grouped into different embodiments to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the claimed embodiments require more features than those expressly cited in each claim. Rather, as the following claims reflect, the subject matter of the invention lies in less than all the features of a single described embodiment.

Claims

Demands

1. A slot scanner illumination system (10) comprising: a chassis (30) having an optical cavity (32) and a front aperture (34), the optical cavity (32) having an optical axis through the latter, the optical axis being an axis along which light can be received by the chassis (30) through the front aperture (34), and the front aperture having a first edge (40a) and a second edge (40b) opposite the first edge; a scanning window configured to at least partially cover the front aperture (34) of the chassis (30), the scanning window having a normal axis orthogonal to a flat surface of the scanning window;a lighting element disposed inside the optical cavity (32) of the chassis (30) in a recessed position relative to the scanning window by a value between three and six centimeters, the lighting element being disposed near the first edge (40a) of the front opening (34), the lighting element being configured to provide illumination along a lighting axis, wherein the lighting axis is not parallel to the optical axis and is at an angle directed towards the second edge (40b) of the front opening (34), and wherein the lighting element provides illumination with an angle of incidence of illumination between 30° and 50° with the normal axis of the scanning window said lighting system being characterized in that the lighting element comprises a plurality of lighting elements disposed in two groups;and a scanning indicator (26) disposed between the two groups, the scanning indicator (26) being a light source which provides illumination following the successful scanning of an item at the level of the slot scanner lighting system.;

2. System (10) according to claim 1, wherein the lighting element is disposed at an angle between 30 and 60 degrees with respect to the normal axis of the scanning window.

3. System (10) according to claim 1, wherein the lighting element is configured to provide lighting having an angle of incidence with the scanning window which results in a value greater than 60% of radiation transmission.

4. System (10) according to claim 1, wherein the lighting element provides illumination to both (i) a field of view of a barcode imaging device, and (ii) a field of view of a color camera.

5. System (10) according to claim 1, further comprising an optical element operationally coupled to the lighting element, the optical element being arranged (i) to receive illumination from the lighting element and (ii) to provide illumination along the lighting axis.

6. System (10) according to claim 1, wherein the lighting element comprises fewer than 6 LEDs.

7. System (10) according to claim 1, wherein the lighting element comprises six LEDs comprising both red LEDs and white LEDs.

8. System (10) according to claim 1, wherein the lighting element comprises a plurality of LEDs.

9. System (10) according to claim 1, wherein the two groups individually comprise one LED each.

10. System (10) according to claim 1, wherein the two groups individually comprise a plurality of LEDs in each group.

11. System (10) according to claim 1, further comprising an image sensor (12) disposed in the optical cavity (32), the sensor being disposed to receive an image through the scanning window, the image sensor having an imaging field of view (FOV) along the optical axis.

12. System (10) according to claim 11, further comprising at least one reflecting mirror (42) at least partially disposed in the optical cavity (32), the at least one reflecting mirror (42) being configured to redirect the FOV of the image sensor (12) through the scanning window.

13. System (10) according to claim 11, wherein the lighting element is configured to provide illumination to the FOV of the image sensor (12).

14. System (10) according to claim 11, wherein the lighting element is arranged to provide illumination with a uniformity ratio U, defined by the maximum to minimum lux of 2 to 1 in the FOV at the scanning window level in which: Ç -Ç jj_ ^max , SniaX ' Smax and Smm are lux expressed in W / m2.

15. System (10) according to claim 11, wherein the lighting element is arranged to provide lighting with a uniformity ratio U, defined by the maximum to minimum lux of a value less than 2 in the FOV between 5.08 cm and 20.32 cm of the scanning window in which: « -Ç jj__ jnin , 7 Smax and Smin are lux expressed in W / m2.

16. System (10) according to claim 11, wherein the image sensor (12) is a color imaging camera.

17. System (10) according to claim 1, wherein the two groups are spaced at least 3.81 cm apart.

18. System (10) according to claim 1, wherein the two groups are configured to illuminate independently and can (i) illuminate simultaneously or (ii) illuminate alternately.

19. System (10) according to claim 1, further comprising a cutting ridge disposed in the optical cavity (32) near the lighting element, in which the cutting ridge is positioned to block at least a portion of the illumination provided by the lighting element.

Images