System and method for improved reading of data from reflective surfaces of electronic devices
09594936 ยท 2017-03-14
Assignee
Inventors
Cpc classification
G06K7/1095
PHYSICS
International classification
Abstract
Disclosed systems and methods for a data reader operable to capture one or more images from items having a highly, or relatively highly, reflective surface. The data reader includes a controller/processor in operative communication with an imager and an illumination system, where the controller/processor is programmed to selectively operate the imager and the illumination systems to interleave the data reader between a first reading period for reading items having a surface with little or no reflectivity and a second reading period for reading items having a surface with high reflectivity. In some embodiments, the items with highly reflective surfaces may include electronic devices, such as mobile phones.
Claims
1. A system for data reading comprising: a window; an imager for capturing an image of an item bearing an optical code, the imager including an imager array divided into a first portion and a non-overlapping second portion; an illumination system for illuminating the item, the illumination system including a first illumination source and a second illumination source, each of which direct light outwardly through the window and into a read region; and a controller in operative communication with the imager and the illumination system, wherein the controller is programmed to operate the imager and the illumination system during a first reading frame at a first time period and during a second reading frame at a subsequent second time period, wherein during the first time period for the first reading frame, the controller is programmed to activate both the first and second illumination sources during a first exposure period of the imager, the controller operating the imager to capture a first image of a first optical code when a first item is present in the read region, wherein the first portion of the imager is exposed during the first exposure period to capture the first image on the first portion of the imager; and wherein during the second time period for the second reading frame, the controller is programmed to activate the first illumination source during a second exposure period of the imager, and deactivate the second illumination source during the second exposure period, the controller operating the imager to capture a second image of a second optical code when a second item is present in the read region, wherein the second portion of the imager is exposed during the second exposure period to capture the second image on the second portion of the imager.
2. The system of claim 1, where the first illumination source is oriented such that illumination generated from the first illumination source is directed toward the window at an acute angle relative to the window, and wherein when the second item is a reflective display of an electronic device, the illumination generated from the illumination source is reflected off the reflective display such that the imager does not detect the illumination from the first illumination source.
3. The system of claim 2, wherein when the item does not have a reflective display, the first illumination source is reflected back toward the imager.
4. The system of claim 1, wherein the processor is further programmed to interleave between the first reading period and the second reading period to capture images of items on the first portion of the imager.
5. The system of claim 4, wherein the processor is further configured to operate the data reader in the first reading period to capture images of items on the second portion of the imager.
6. The system of claim 4, wherein the processor is configured to interleave between the first and second reading periods at an interleaving ratio of 1:1.
7. The system of claim 1, wherein during the first reading period, the processor is programmed to pulse the first and second illumination sources substantially simultaneously at a pulse rate at least equal to the first exposure period of the imager.
8. The system of claim 1, wherein during the second reading period, the processor is programmed to pulse the first illumination source at a pulse rate at least equal to the first exposure period of the imager.
9. The system of claim 1, wherein during the first reading period, the processor is programmed to activate the first illumination source and then the second illumination source in sequence during the first exposure period of the imager.
10. A method for data reading using a data reader having a window, an imager for capturing an image of an item, the imager including an imager array divided into a first portion and a non-overlapping second portion, and an illumination system including a first illumination source and a second illumination source, the method comprising the steps of: in a first reading frame at a first time period, activating, via a processor, the first and second illumination sources during a first exposure period of the imager to direct light outwardly from the window and into a read region; exposing, via the processor, the first portion of the imager during the first exposure period; if a first item is present in the read region, capturing, via the imager, a first image of the first item on the first portion of the imager during the first exposure period; and in a second reading frame at a second time period subsequent to the first time period, activating, via a processor, the first illumination sources during the second exposure period to direct light outwardly from the window and into a read region; deactivating, via the processor, the second illumination sources during the second exposure period; exposing, via the processor, the second portion during the second exposure period; and if a second item is present in the read region, capturing, via the imager, a second image of the second item on the second portion of the imager during the second exposure period.
11. The method of claim 10, further comprising interleaving, via the processor, between the first reading period and the second reading period to capture images of items on the first portion of the imager.
12. The method of claim 11, further comprising operating, via the processor, the data reader in the first reading period to capture images of items on the second portion of the imager.
13. The method of claim 12, further comprising interleaving, via the processor, between the first and second reading period at an interleaving ratio of 1:1.
14. The method of claim 10, further comprising pulsing, via the processor, the first and second illumination sources substantially simultaneously at a pulse rate at least equal to the first exposure period of the imager during the first reading period.
15. The method of claim 10, further comprising pulsing, via the processor, the first illumination source at a pulse rate at least equal to the first exposure period of the imager during the second reading period.
16. The method of claim 10, further comprising activating, via the processor, the first illumination source and then the second illumination source in sequence during the first exposure period of the imager during the first reading period.
17. A system for data reading comprising: a window; an imager for capturing an image of an item bearing an optical code; an illumination system for illuminating the item, the illumination system including a first illumination source and a second illumination source, each of which direct light outwardly through the window and into a read region, where the first illumination source is oriented such that illumination generated from the first illumination source is directed toward the window at an acute angle relative to the window, and wherein when the second item is a reflective display of an electronic device, the illumination generated from the illumination source is reflected off the reflective display such that the imager does not detect the illumination from the first illumination source; and a controller in operative communication with the imager and the illumination system, wherein the controller is programmed to operate the imager and the illumination system during a first reading period and a different second reading period, wherein during the first reading period, the controller is programmed to activate both the first and second illumination sources during a first exposure period of the imager, the controller operating the imager to capture a first image of a first optical code when a first item is present in the read region; and wherein during the second reading period, the controller is programmed to activate the first illumination source during a second exposure period of the imager, and deactivate the second illumination source during the second exposure period, the controller operating the imager to capture a second image of a second optical code when a second item is present in the read region.
18. The system of claim 17, wherein the imager is an imager array divided into a first portion and a non-overlapping second portion, and wherein the processor is further programmed to interleave between the first reading period and the second reading period to capture images of items on the first portion of the imager.
19. The system of claim 18, wherein the processor is further configured to operate the data reader in the first reading period to capture images of items on the second portion of the imager.
20. The system of claim 18, wherein the processor is configured to interleave between the first and second reading periods at an interleaving ratio of 1:1.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
(8) With reference to the drawings, this section describes particular embodiments and their detailed construction and operation. The embodiments described herein are set forth by way of illustration only and not limitation. The described features, structures, characteristics, and methods of operation may be combined in any suitable manner in one or more embodiments. In view of the disclosure herein, those skilled in the art will recognize that the various embodiments can be practiced without one or more of the specific details or with other methods, components, materials, or the like. For the sake of clarity and conciseness, certain aspects of components or steps of certain embodiments are presented without undue detail where such detail would be apparent to those skilled in the art in light of the teachings herein and/or where such detail would obfuscate an understanding of more pertinent aspects of the embodiments.
(9) In the following description of the figures and any example embodiments, the system may be referred to in conjunction with use at a retail establishment. It should be understood that such use is merely one example use for such a system. Other uses for a system with the characteristics and features described herein may be implemented, for example, in an industrial location such as a parcel distribution (e.g., postal) station or for processing inventory, as well as other suitable uses that may involve reading optical codes from electronic devices or other reflective surfaces. In addition, for convenience, certain embodiments may refer to the data reader operable for capturing optical codes from a mobile or cellular phone. It should be understood that this is merely one example embodiment and use of the system with the features and functionalities described herein. The system may be used to capture optical codes from any suitable device or product having a reflective surface.
(10) For convenience, the following description may at times refer to the data reader having a normal label reading mode or period and an electronic device reading mode or period. References to the normal label reading mode or period may refer to instances where the data reader is used to obtain images from items having surfaces with little or no reflectivity such that specular reflection issues do not meaningfully interfere with an ability of the data reader to capture a decodable image (i.e., reflected illumination does not saturate the imager). References to the electronic device reading mode or period may refer to instances where the data reader is used to obtain images from items having surfaces with high reflectivity, and in some cases self-illuminating displays, such as electronic devices with LCD display screens, where reflected illumination may saturate the imager and interfere with an ability of the data reader to capture a decodable image from an electronic device. These references are meant to establish a frame of reference for convenience purposes and are not intended to otherwise limit the disclosure.
(11) Collectively,
(12) For example, with reference to
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(15) The data reader 10 may acquire an image of the read region 28 using anyone of a variety of mirror configurations. In one embodiment, an image of the read region 28 may be divided into a first portion 28a and a second portion 28b, each of which may be reflected off a series of mirrors (or other optical components) toward focusing optics 30, which in turn focuses the portions 28a, 28b onto the imager 32. For example, the first portion 28a may be reflected sidewardly by a first mirror 34 toward a second mirror 36, which directs the first portion 28a toward the focusing optics 30. Similarly, the second portion 28b may be reflected sidewardly by a third mirror 38 toward a fourth mirror 40, which directs the second portion 28b toward the focusing optics 30. In other embodiments, the mirrors may be arranged in a different configuration suitable to provide an image of the read region 28 onto the imager 32.
(16) Preferably, the mirrors are arranged so that at least one portion (e.g., 28c in
(17) The imager 32, alone or together with logic components such as a complex programmable logic device (CPLD) or a field-programmable gate array (FPGA), is coupled to a controller or processor 44, which, among other functions, is preferably programmed to control operating parameters of the data reader 10 as discussed in further detail below. Processor 44 is also preferably programmed to read and decode optical codes or other symbols or imaged items. The processor 44 may comprise any suitable digital processor, such as a low-power DSP core or ARM core processor. In some embodiments, processor 44 comprises an ARM9 processor AT91SAM9G20 sold by Atmel of San Jose, Calif., USA, or OMAP processor sold by Texas Instruments of Dallas, Tek, USA or an i.MX1 series processor (such as the MC9328MX1 processor) sold by Freescale Semiconductor, Inc, of Austin, Tex., USA. Alternately, multiple processors or sub-processors or other types of processor electronics such as comparators or other specific function circuits may be used alone or in combination. For the purposes of this description, the term processor is meant to include any of these combinations.
(18) In one embodiment, the processor 44 and on-board memory 46 are mounted on PCB 42 adjacent the imager 32, and are operable for controlling operation of the imager 32 and other reader components. The memory 46 may be flash memory, random access memory, or other suitable memory in communication with the processor 44. In some embodiments, memory 46 may be integrated with processor 44.
(19) As mentioned previously, the data reader 10 includes illumination sources 24, 26 to illuminate the optical code on the item presented to the data reader 10. In one embodiment, the illumination sources 24, 26 comprise a collection of LEDs, for example, infrared or visible spectrum LEDs, but may alternatively comprise another suitable light source, such as a lamp or laser diode. The illumination sources 24, 26 may be coupled to and controlled by the processor 44 or may be remotely mounted and powered.
(20) With reference to
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(23) It should be understood that the acute angle may depend on various factors, such as the number and arrangement of illumination sources 24, and a distance of the illumination sources 24 to the window 22. In addition, different light sources may have different light dispersion fields depending on various factors of the light source. For example, in one embodiment, the dispersion field may be conically shaped. Assuming the dispersion field of the illumination sources 24 is conically shaped, the acute angle may be measured based on a center line of the conical dispersion field.
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(25) The reading scenario illustrated in
(26) With collective reference to
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(28) Turning back to
(29) At time T.sub.2, for View 1, the processor 44 activates both illumination sources 24, 26 and sets an exposure time equal to the pulse rate of the illumination sources 24, 26 in a similar fashion as during T.sub.1. As mentioned previously, View 1 is interleaved between a normal data reading mode or period (when both illumination sources 24, 26 are activated) and an electronic device reading mode or period (when only illumination source 24 is activated). At time T.sub.2, the processor 44 is operating the illumination sources 24, 26 and setting the exposure time to operate the data reader 10 in a normal reading mode or period for View 1.
(30) At time T.sub.3, the processor 44 again activates both illumination sources 24, 26 and sets an exposure time equal to the pulse rate of the illumination sources 24, 26 in a similar fashion as during T.sub.1. During time T.sub.3, the data reader 10 continues operating in a normal label reading mode or period.
(31) At time T.sub.4, the data reader 10 switches to an electronic device reading mode or period. During time T.sub.4, the processor 44 controls illumination sources 24, 26 so that illumination source 24 is activated during the exposure time while illumination source 26 is not activated. In this configuration, View 1 captures an image from the electronic device 16 when it is present in the read region 28. Because the illumination source 26 is not active during the exposure time, the illumination from illumination source 26 does not saturate the image obtained by the imager 32 in View 1. As was described previously with respect to
(32) In some embodiments, as illustrated in
(33) The same process described during times T.sub.1 through T.sub.4 may be repeated again at times T.sub.5 through T.sub.8 (and so on) in a similar fashion to interleave the data reader 10 between a normal item reading mode and an electronic device reading mode.
(34) It should be understood that the scenario described with reference to
(35) In other embodiments, the processor 44 may operate and control the illumination sources 24, 26 and the exposure times in a different manner to effectively alternate between the normal reading and electronic device reading modes. In one embodiment, the processor 44 may operate in a multiple integration mode with a long exposure time and cycling the illumination sources 24, 26 independently from one another during the exposure time.
(36) For example, with reference to
(37) At time T.sub.4, the processor 44 alternates to the electronic device reading mode. In this arrangement, the processor 44 activates illumination source 24 during a first portion of the exposure time, and thereafter deactivates illumination source 24 during a second portion of the exposure time. During time T.sub.4, the Illumination source 26 is not activated at any point during the exposure time of the imager 32 to minimize or avoid reflected illumination into the imager 32 from illumination source 26. As described previously and illustrated in
(38) It should be understood that the scenario described with reference to
(39) In other embodiments, the processor may be programmed to pulse one or more of the illumination sources to avoid or minimize the perception of illumination flicker by a user or bystander while implementing methods for reading optical codes presented on electronic display screens or other highly reflective surfaces. Additional details relating to example embodiments are described in U.S. Pat. No. 9,122,939, the disclosure of which is incorporated by reference herein in its entirety.
(40) While certain preferred systems and methods have been shown and described, it will be apparent to one skilled in the art that modifications, alternatives and variations are possible without departing from the inventive concepts set forth herein. Therefore, the invention is intended to embrace all such modifications, alternatives and variations.