System and method for illuminating and reading optical codes imprinted or displayed on reflective surfaces

• US 7,163,149 B2
• Filed: 03/02/2004
• Issued: 01/16/2007
• Est. Priority Date: 03/02/2004
• Status: Active Grant

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: He, Duanfeng, Joseph, Eugene B.
• Primary Examiner(s): PAIK, STEVEN SANGYUL
• Application Number:
  US10/791,018
• Publication Number:
  US 20050194447A1
• Time in Patent Office: 1,050 Days
• Field of Search: 235/454
• US Class Current: 235/454
• CPC Class Codes: G06K 7/10732 Light sources
• CPC Class Codes: G06K 7/10742 including a diffuser for diffusing the light from the light source to create substantially uniform illumination of the target record carrier

Abstract

An optical code reading system and method are provided for reading optical codes imprinted or displayed on, or behind, reflective surfaces. The system includes an extended light source, including one of a backlight assembly and a frontlight assembly, emitting an extended-beam light for directly illuminating an optical code, at least one image sensor for sensing light reflected by the optical code and generating signals related to at least one image of the optical code, and at least one processor for processing at least a portion of the signals, generating a decodable image corresponding to the signals, and decoding at least a portion of the decodable image.

Claims

1. An optical code reading system comprising:

an extended light source emitting an extended-beam light for directly illuminating an optical code with an illuminating light, the extended light source including one of a backlight assembly and a frontlight assembly;

at least one direct point light source for illuminating the optical code with narrow-beam light;

at least one image sensor for sensing the illuminating light reflected by the optical code and generating signals related to at least one image of the optical code; and

at least one processor for processing at least a portion of the signals, generating a decodable image corresponding to the signals and decoding at least a portion of the decodable image.

2. The optical code reading system as in claim 1, wherein the at least one processor is further configured for selectively operating one of the extended light source and the at least one direct point light source.

3. The optical code reading system as in claim 2, wherein the at least one processor is further configured for determining at least one optical property of the imaged optical code, and the extended light source and the at least one direct point light source are selectively operated in accordance with the determined at least one optical property.

4. The optical code reading system as in claim 2, wherein the at least one processor alternately operates the extended light source and the at least one direct point light source for respective consecutive imaging captures of a series of imaging captures by the optical code system.

5. The optical code reading system as in claim 1, wherein the at least one processor is further configured for determining the imaged optical code'"'"'s code-type, wherein the code-type is selected from the group comprising:

a UPC code-type, a DataMatrix code-type or a QR code-type.

6. The optical code reading system as in claim 1, wherein at least a portion of the optical code reading system is configured and dimensioned to be included in a handheld device having a lens and an image sensor acting as a camera and one of a backlit and a frontlit display for displaying data and providing the extended light source.

7. The optical code reading system as in claim 6, wherein the handheld device is one of a handheld computer device and a mobile phone.

8. The optical code reading system as in claim 1, further comprising a display screen for displaying data, wherein the extended light source further provides illumination for the display of data on the display screen to a user.

9. The optical code reading system as in claim 1, wherein the extended light source is a frontlight assembly, the optical code is positioned in front of the extended light source, and the at least one image sensor is positioned behind the extended light source.

10. The optical code reading system as in claim 1, further comprising at least one direct point light source positioned behind the extended light source for illuminating the optical code with narrow-beam light.

11. The optical code reading system as in claim 1, wherein the extended light source includes a plurality of LEDs and a lightpipe receiving light emitted by the plurality of LEDs and emitting the extended-beam light.

12. The optical code reading system as in claim 11, wherein at least a portion of the plurality of LEDs are packaged together in at least one LED light bar.

13. The optical code reading system of claim 1, further comprising an LCD positioned in front of or behind the extended light source.

14. A method for reading an optical code on a target surface comprising the steps of:

emitting with at least one of a backlight and frontlight assembly an extended-beam light towards the optical code for directly illuminating the optical code with an illuminating light;

emitting a narrow-beam light for illuminating the optical code;

sensing the illuminating light reflected from the optical code;

generating at least one image of the optical code corresponding to the sensed light; and

decoding at least a portion of the at least one image.

15. The method as in claim 14, further comprising the step of determining at least one optical property of the imaged optical code.

16. The method as in claim 14, wherein the optical code is a UPC code, a Data Matrix code or a QR code.

17. The method as in claim 14, further comprising the step of controlling the emission of the extended-beam light and the emission of the narrow-beam light for selectively emitting at least one of the extended-beam light and the narrow-beam light.

18. The method as in claim 17, wherein the controlling step further includes alternating between emitting the extended-beam light and emitting the narrow-beam light for respective consecutive imaging captures of a series of imaging captures.

19. The method as in claim 14, further comprising the step of clearing data displayed on a display screen coupled to the at least one of the backlight and frontlight assembly prior to illuminating the optical code.

20. A handheld processing device comprising:

an illuminated display disposed within a housing for displaying data, the illuminated display being configured to provide an extended-beam light for illuminating an optical code with an illuminating light;

a camera disposed within the housing for sensing the optical code illuminated by the illuminated display and generating corresponding signals; and

at least one processor configured for processing the signals, wherein the at least one processor further controls illumination of the display and clearance of the display of data when dual-use illumination is used for illuminating the optical code.

21. The handheld processing device as in claim 20, further comprising a light source providing narrow-beam illumination to the optical code.

22. The handheld processing device as in claim 20, wherein the handheld processing device is a handheld computer device.

23. The handheld processing device as in claim 20, wherein the handheld processing device is a mobile phone.

24. The handheld processing device as in claim 20, wherein the illuminated display is an LCD screen illuminated by at least one of a backlight assembly and a frontlight assembly configured to display information relating to the imaged optical code.

25. The handheld processing device as in claim 20, wherein the camera includes an auto-focus system for automatically focusing light reflected by the optical code onto the image sensor.

26. The handheld processing device as in claim 20, wherein the optical code is selected from a group comprising:

UPC, Data Matrix, and QR codes.

27. The handheld processing device as in claim 20, wherein the at least one processor further controls the light source.

28. A method for reading an optical code comprising the steps of:

providing for receiving an optical code read activation signal;

providing for clearing displayed data on a display screen in response to the activation signal;

providing for controlling illumination of the display for providing illumination of the optical code with an extended-beam light; and

providing for controlling illumination of a direct point light source for illuminating the optical code with narrow-beam light.

29. The method as in claim 28, further comprising the step of providing for determining at least one optical property associated with the optical code, wherein the controlling illumination of the display step and controlling illumination of the direct point light source is in accordance with the at least one optical property.

30. The method as in claim 28, wherein the controlling illumination of the display step and controlling illumination of the direct point light source are performed for alternately illuminating the display and the direct point light source for respective consecutive imaging captures of a series of imaging captures.

31. A computer readable medium storing a set of computer readable instructions capable of being executed by at least one processor for reading an optical code, the readable instructions comprising:

means for providing for receiving an optical code read activation signal;

means for providing for clearing displayed data on a display screen in response to the activation signal;

means for providing for controlling illumination of the display for providing illumination of the optical code with extended-beam light; and

means for providing for controlling illumination of a direct point light source for illuminating the optical code with narrow-beam light.