Image reader comprising CMOS based image sensor array

Patent metadata

Field	Value
Publication number	US-10735684-B2
Application number	US-201916728810-A
Country	US
Kind code	B2
Filing date	Dec 27, 2019
Priority date	Mar 11, 2005
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

The invention features an image reader and a corresponding method for capturing a sharp distortion free image of a target, such as a one or two-dimensional bar code. In one embodiment, the image reader comprises a two-dimensional CMOS based image sensor array, a timing module, an illumination module, and a control module. The time during which the target is illuminated is referred to as the illumination period. The capture of the image by the image sensor array is driven by the timing module that, in one embodiment, is able to simultaneously expose substantially all of the pixels in the array. The time during which the pixels are collectively activated to photo-convert incident light into charge defines the exposure period for the sensor array. In one embodiment, at least a portion of the exposure period occurs during the illumination period.

First claim

We claim:

1. An apparatus comprising:
a CMOS image sensor having a plurality of pixels in a two-dimensional array, wherein the CMOS image sensor is operable to capture image data in a global shutter mode, and wherein, in the global shutter mode, all or substantially all of the plurality of pixels in the CMOS image sensor are configured to be simultaneously exposed for a duration of an exposure period;
at least one illumination light source configured to illuminate at least a portion of a two-dimensional bar code for an illumination period, wherein the illumination period is dependent on the exposure period and at least one parameter related to an ambient light intensity;
a processor; and
a non-transitory memory including computer program instructions configured to, when executed by the processor, cause the apparatus to decode the image data, wherein the image data comprises at least a representation of the two-dimensional bar code.

2. The apparatus of claim 1 , wherein the non-transitory memory including the computer program instructions is further configured to, when executed by the processor, cause the apparatus to select a decoding algorithm for decoding the representation of the two-dimensional bar code from a plurality of decoding algorithms.

3. The apparatus of claim 1 , wherein the at least one illumination light source is configured to project a two-dimensional observable illumination pattern over the two-dimensional bar code.

4. The apparatus of claim 1 further comprising an infrared filter.

5. The apparatus of claim 1 , wherein the at least one illumination light source is configured to operate at a peak power level during at least a portion of the exposure period and is configured to be deactivated during another portion of the exposure period.

6. The apparatus of claim 1 , wherein the illumination period is less than a frame time of the CMOS image sensor.

7. The apparatus of claim 1 , wherein the non-transitory memory including the computer program instructions is further configured to, when executed by the processor, cause the apparatus to at least decode an additional bar code detected in the image data.

8. The apparatus of claim 1 , wherein the at least one illumination light source is configured to be substantially bright and the exposure period is configured to be substantially short so as to enable the image data to be substantially non-distorted.

9. The apparatus of claim 1 , wherein the at least one illumination light source is configured to be operated above a maximum DC operation current draw rating.

10. The apparatus of claim 1 , wherein a read out control timing signal begins at a conclusion of the exposure period.

11. The apparatus of claim 1 , wherein the non-transitory memory including the computer program instructions is further configured to, when executed by the processor, cause the apparatus to perform feature extraction such that a quiet zone is identifiable in the image data.

12. The apparatus of claim 1 , wherein the non-transitory memory including the computer program instructions is further configured to, when executed by the processor, cause the apparatus to perform feature extraction such that a finder pattern is identifiable in the image data.

13. An apparatus comprising:
a CMOS image sensor having a plurality of pixels in a two-dimensional array, wherein the CMOS image sensor is operable to capture image data in a global shutter mode, and wherein, in the global shutter mode, all or substantially all of the plurality of pixels in the CMOS image sensor are configured to be simultaneously exposed for a duration of an exposure period, wherein at least one instance of the exposure period has a duration of less than 3.7 milliseconds;
at least one illumination light source configured to illuminate at least a portion of a two-dimensional bar code for an illumination period, wherein the illumination period is dependent on the exposure period and at least one parameter related to an ambient light intensity;
a processor; and
a non-transitory memory including computer program instructions configured to, when executed by the processor, cause the apparatus to decode the image data, wherein the image data comprises at least a representation of the two-dimensional bar code.

14. The apparatus of claim 13 , wherein the at least one illumination light source is configured to be operated above a maximum DC operation current draw rating.

15. The apparatus of claim 13 further comprising an infrared filter.

16. The apparatus of claim 13 , wherein the at least one illumination light source is configured to project a two-dimensional observable illumination pattern over the two-dimensional bar code and wherein the at least one illumination light source is configured to be substantially bright and the exposure period is configured to be substantially short so as to enable the image data to be substantially non-distorted.

17. The apparatus of claim 13 , wherein the non-transitory memory including the computer program instructions is further configured to, when executed by the processor, cause the apparatus to perform feature extraction such that a quiet zone is identifiable in the image data.

18. The apparatus of claim 13 , wherein the non-transitory memory including the computer program instructions is further configured to, when executed by the processor, cause the apparatus to perform feature extraction such that a finder pattern is identifiable in the image data.

19. An apparatus comprising:
a CMOS image sensor having a plurality of pixels in a two-dimensional array, wherein the CMOS image sensor is operable to capture image data in a global shutter mode, and wherein, in the global shutter mode, all or substantially all of the plurality of pixels in the CMOS image sensor are configured to be simultaneously exposed for a duration of an exposure period;
at least one illumination light source configured to illuminate at least a portion of a two-dimensional bar code for an illumination period, wherein the illumination period is dependent on at least one parameter related to an ambient light intensity;
a processor; and
a non-transitory memory including computer program instructions configured to, when executed by the processor, cause the apparatus to:
search the image data for one or more markers; and
in an instance in which at least one marker of the one or more markers is detected, decode the image data based on the at least one marker, wherein the image data comprises at least a representation of the two-dimensional bar code.

20. The apparatus of claim 19 , wherein the at least one illumination light source is configured to be operated above a maximum DC operation current draw rating.

21. The apparatus of claim 19 further comprising an infrared filter.

22. The apparatus of claim 19 , wherein the at least one illumination light source is configured to project a two-dimensional observable illumination pattern over the two-dimensional bar code and wherein the at least one illumination light source is configured to be substantially bright and the exposure period is configured to be substantially short so as to enable the image data to be substantially non-distorted.

23. The apparatus of claim 19 , wherein the non-transitory memory including the computer program instructions is further configured to, when executed by the processor, cause the apparatus to perform feature extraction such that a quiet zone is identifiable in the image data.

Assignees

• Hand Held Prod Inc

Inventors

• Wang Ynjiun P
• Havens William H

Classifications

• G06K7/10722 Primary

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