DETECTING WINDOW DETERIORATION ON BARCODE SCANNING WORKSTATION

• US 20160034722A1
• Filed: 07/31/2014
• Published: 02/04/2016
• Est. Priority Date: 07/31/2014
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: JOSEPH, EUGENE B., HE, DUANFENG
• Granted Patent: US 9,298,957 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06K 7/0095 Testing the sensing arrangement, e.g. testing if a magnetic card reader, bar code reader, RFID interrogator or smart card reader functions properly testing of electrical circuits G01R31/28
• CPC Class Codes: G06K 7/10712 Fixed beam scanning
• CPC Class Codes: G06K 7/1096 the scanner having more than one scanning window, e.g. two substantially orthogonally placed scanning windows for integration into a check-out counter of a super-market
• CPC Class Codes: H04N 1/00029 Diagnosis, i.e. identifying a problem by comparison with a normal state
• CPC Class Codes: H04N 1/4097 Removing errors due external factors, e.g. dust, scratches

Abstract

A method of operating a workstation includes capturing multiple monitoring images each being captured with the imaging sensor while the illumination light source is energized during one of multiple short exposure-time-periods, and detecting a checkup-condition that includes analyzing the multiple monitoring images to determine the presence of any adverse feature on workstation'"'"'s window. Each of the multiple short exposure-time-periods is shorter than four times of a threshold exposure-time-period but no shorter than 25% of the threshold exposure-time-period. The threshold exposure-time-period is a minimal exposure-time-period needed for the imaging sensor to capture recognizable patterns of a barcode that is in directing contacting with the window while the illumination light source is energized.

Claims

1. A method of operating a workstation having an imaging sensor located within a housing that has a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane, the workstation having two modes of operation including a barcode-scanning mode of operation and a monitoring mode of operation, the method comprising:

projecting illumination light through one of the windows by energizing a illumination light source within the housing, intended for capturing at least one image with the imaging sensor;

capturing multiple monitoring images each being captured with the imaging sensor while the illumination light source is energized during one of multiple monitoring exposure-time-periods associated with the monitoring mode of operation, wherein each of the multiple monitoring exposure-time-periods is below the threshold exposure-time-period, wherein the threshold exposure-time-period is an exposure-time-period that allows the imaging sensor to capture first patterns of a barcode with said first patterns being decodable when said barcode is in direct contact with said one of the windows while the illumination light source is energized, and wherein the threshold exposure-time-period is 110% of a sub-threshold exposure-time-period that allows the imaging sensor to capture second patterns of the barcode with said second patterns being undecodable when said barcode is in direct contact with said one of the windows while the illumination light source is energized; and

detecting a checkup-condition including analyzing the multiple monitoring images to determine the presence of at least one image of an adverse feature that includes a piece of dirt, a scratch mark, and a spill mark on said one of the windows.

2. The method of claim 1, further comprising:

generating at least one of an audio cue and a visual cue when the checkup-condition is detected.

3. The method of claim 1, further comprising:

reporting a type of adverse feature when the checkup-condition is detected, the type of adverse feature including information about whether said one of the windows gets dirty, scratched or damaged.

4. The method of claim 1, wherein said detecting comprises:

detecting the checkup-condition when at least one of the multiple monitoring images is sufficiently different from at least another one of the multiple monitoring images to indicate the presence of at least one image of an adverse feature.

5. The method of claim 1, further comprising:

obtaining multiple differential monitoring images that includes subtracting each of the multiple monitoring images by a corresponding background image associated therewith that is captured with the imaging sensor while the illumination light source is de-energized; and

detecting the checkup-condition when at least one of the multiple differential monitoring images is sufficiently different from at least another one of the multiple differential monitoring images to indicate the presence of at least one image of an adverse feature.

6. The method of claim 1, further comprising:

obtaining multiple differential monitoring images that includes subtracting each of the multiple monitoring images by a corresponding background image associated therewith that is captured with the imaging sensor while the illumination light source is de-energized during a corresponding identical short exposure-time-period associated therewith; and

detecting the checkup-condition when at least one of the multiple differential monitoring images is sufficiently different from at least another one of the multiple differential monitoring images to indicate the presence of at least one image of an adverse feature.

10. The method of claim 1, further comprising:

capturing multiple normal images each being captured with the imaging sensor while the illumination light source is energized during one of multiple exposure-time-periods associated with the barcode-scanning mode of operation, wherein each normal image capturing an object outside the housing and having at least one barcode therein that is successfully decodable; and

wherein said at least one of the multiple monitoring images is captured before the capturing of the multiple normal images, and said at least another one of the multiple monitoring images after the capturing of the multiple normal images.

7. (canceled)

8. (canceled)

9. (canceled)

11. A workstation comprising:

a housing having a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane;

an imaging sensor within the housing and having an array of photosensitive elements;

an illumination system having an illumination light source within the housing and configured for projecting illumination light through one of the windows when the illumination light source is energized;

a controller operatively connected to the imaging sensor and the illumination system for controlling the workstation in a barcode-scanning mode of operation and a monitoring mode of operation, and configured for capturing multiple monitoring images each being captured with the imaging sensor while the illumination light source is energized during one of multiple monitoring exposure-time-periods associated with the monitoring mode of operation, wherein each of the multiple monitoring exposure-time-periods is below the threshold exposure-time-period, wherein the threshold exposure-time-period is an exposure-time-period that allows the imaging sensor to capture first patterns of a barcode with said first patterns being decodable when said barcode is in direct contact with said one of the windows while the illumination light source is energized, and wherein the threshold exposure-time-period is 110% of a sub-threshold exposure-time-period that allows the imaging sensor to capture second patterns of the barcode with said second patterns being undecodable when said barcode is in direct contact with said one of the windows while the illumination light source is energized; and

wherein the controller is further configured for detecting a checkup-condition including analyzing the multiple monitoring images to determine the presence of at least one image of an adverse feature that includes a piece of dirt, a scratch mark, and a spill mark on said one of the windows.

12. The workstation of claim 11, wherein the controller is further configured to generate at least one of an audio cue and a visual cue when the checkup-condition is detected.

13. The workstation of claim 11, wherein the controller is further configured to report a type of adverse feature when the checkup-condition is detected, the type of adverse feature including information about whether said one of the windows gets dirty, scratched or damaged.

14. The workstation of claim 11, wherein said detecting comprising:

detecting the checkup-condition when at least one of the multiple monitoring images is sufficiently different from at least another one of the multiple monitoring images to indicate the presence of at least one image of an adverse feature.

15. The workstation of claim 11, wherein the controller is further configured for

obtaining multiple differential monitoring images that includes subtracting each of the multiple monitoring images by a corresponding background image associated therewith that is captured with the imaging sensor while the illumination light source is de-energized;

and

wherein said detecting comprises detecting the checkup-condition when at least one of the differential multiple monitoring images is sufficiently different from at least another one of the differential multiple monitoring images to indicate the presence of at least one image of an adverse feature.

16. The workstation of claim 11, wherein the controller is further configured for

obtaining multiple differential monitoring images that includes subtracting each of the multiple monitoring images by a corresponding background image associated therewith that is captured with the imaging sensor while the illumination light source is de-energized during a corresponding identical short exposure-time-period associated therewith;

and

wherein said detecting comprises detecting the checkup-condition when at least one of the differential multiple monitoring images is sufficiently different from at least another one of the differential multiple monitoring images to indicate the presence of at least one image of an adverse feature.

17. (canceled)

18. (canceled)

19. (canceled)

20. A method of operating a workstation having an imaging sensor located within a housing that has a first window in an upright plane and a second window in a generally horizontal plane that intersects the upright plane, the workstation having two modes of operation including a barcode-scanning mode of operation and a monitoring mode of operation, the method comprising:

projecting illumination light through one of the windows by energizing a illumination light source within the housing, intended for capturing at least one image with the imaging sensor;

capturing multiple monitoring images each being captured with the imaging sensor while the illumination light source is energized during one of multiple monitoring exposure-time-periods associated with the monitoring mode of operation, wherein each of the multiple monitoring exposure-time-periods is below the threshold exposure-time-period, wherein the threshold exposure-time-period is an exposure-time-period that allows the imaging sensor to capture first patterns of a barcode with said first patterns being decodable when said barcode is in direct contact with said one of the windows while the illumination light source is energized, and wherein the threshold exposure-time-period is 110% of a sub-threshold exposure-time-period that allows the imaging sensor to capture second patterns of the barcode with said second patterns being undecodable when said barcode is in direct contact with said one of the windows while the illumination light source is energized; and

detecting a checkup-condition when at least one monitoring image differ from multiple other monitoring images with one or more additional image feature.