Hand-held dataform reader having multiple target area illumination sources for independent reading of superimposed dataforms

• US 6,669,093 B1
• Filed: 12/19/1997
• Issued: 12/30/2003
• Est. Priority Date: 12/19/1997
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Telxon Corporation (Zebra Technologies Corporation)
• Inventors: Meyerson, Robert F., Feng, Chen
• Primary Examiner(s): FUREMAN, JARED
• Application Number:
  US08/994,821
• Time in Patent Office: 2,202 Days
• Field of Search: 235/454, 235/462.2, 235/462.21, 235/462.07, 235/462.25, 235/462.42, 235/462.45, 235/462.46, 235/468, 235/472.01, 235/472.02, 235/491, 235/462.01, 235/494, 250/271, 250/566, 250/568, 382/183, 382/227, 382/312, 382/318
• US Class Current: 235/472.01
• CPC Class Codes: G06K 2019/06225 using wavelength selection, e.g. colour code
• CPC Class Codes: G06K 7/12 using a selected wavelength, e.g. to sense red marks and ignore blue marks

Abstract

A portable data collection device having a modular imaging-based dataform reader. The dataform reader is adapted to independently read first and second overlying dataforms, the first dataform is imaged and decoded when illuminated by radiation having a first wavelength and the second dataform is imaged and decoded when illuminated by radiation having a second wavelength. Control and selection circuitry is electrically coupled to an imaging assembly and an illumination assembly to actuate the imaging assembly and selectively energize a first illumination source which generates radiation having a first range of wavelengths to image and decode the first dataform while a second illumination source is deenergized and to actuate the imaging assembly and selectively energize the second illumination source which generates radiation having a second range of wavelengths to image and decode the second dataform while the first illumination source is deenergized.

Claims

1. A dataform reader for a portable data collection device, the dataform reader utilizing a single two dimensional imaging assembly adapted to independently image and decode first and second overlying dataforms, the first dataform being imaged when illuminated by illumination having a first wavelength and the second dataform being imaged when illuminated by illumination having a second wavelength, the first and second wavelengths being different, the dataform reader comprising:

a) the single two dimensional imaging assembly including a two dimensional photosensor array, the imaging assembly actuatable to generate a signal representative of an image of a target area of the imaging assembly, the target area image resulting from an illumination pattern received from the target area;

b) the imaging assembly including signal and image processing circuitry for processing and decoding an image of a dataform positioned in the target area;

c) an optic assembly positioned with respect to the imaging assembly to focus the reflected illumination from the target area onto the photosensor array;

d) an illumination assembly including a first illumination source energizable to generate illumination having a first range of wavelengths and a second illumination source energizable to generate illumination having a second range of wavelengths, the first range of wavelengths including the first wavelength and not including the second wavelength and the second range of wavelengths including the second wavelength and not including the first wavelength, the first and second illumination sources being positioned to illuminate the target area when actuated;

e) control and selection circuitry electrically coupled to the imaging assembly and the illumination assembly to actuate the imaging assembly and selectively energize the first illumination source to image and decode the first dataform and to actuate the imaging assembly and selectively energize the second illumination source to image and decode the second dataform;

f) wherein the first illumination source illuminates the target area with illumination having a spectral output centered about a wavelength in the visible spectrum; and

g) wherein the control and selection circuitry deenergizes the second illumination source while the first illumination source is energized and deenergizes the first illumination source while the second illumination source is energized.

2. The dataform reader of claim 1 where the second illumination source illuminates the target area with illumination having a spectral output centered about a wavelength in the ultraviolet spectrum.

3. The dataform reader of claim 1 wherein the first illumination source comprises red light emitting diodes.

4. The dataform reader of claim 1 wherein the first illumination source illuminates the target area with illumination having a spectral output centered about a wavelength of substantially 660 nanometers.

5. The dataform reader of claim 1 wherein the second illumination source illuminates the target area with illumination having wavelengths in the ultraviolet spectrum.

6. The dataform reader of claim 5 wherein the second illumination source illuminates the target area with illumination having a spectral output centered about a wavelength of substantially 254 nanometers.

7. The dataform reader of claim 6 wherein the second illumination source comprises an ultraviolet lamp.

8. The dataform reader of claim 1 wherein the optics assembly includes a ultraviolet light filter to prevent illumination having wavelengths in the ultraviolet spectrum from being focused onto the photosensor array.

9. The dataform reader of claim 1 wherein the two dimensional photosensor array, the optics assembly and the illumination assembly are supported by a modular housing, the photosensor array being supported within an internal region of the modular housing.

10. A dataform reader for a portable data collection device, the dataform reader utilizing a single two dimensional imaging assembly adapted to independently image and decode first and second overlying dataforms, the first dataform being imaged when illuminated by illumination having a first wavelength and the second dataform being imaged when illuminated by illumination having a second wavelength, the first and second wavelengths being different, the dataform reader comprising:

a) the single two dimensional imaging assembly including a two dimensional photosensor array, the imaging assembly actuatable to generate a signal representative of an image of a target area of the imaging assembly, the target area image resulting from an illumination pattern received from the target area;

b) the imaging assembly including signal and image processing circuitry for processing and decoding an image of a dataform positioned in the target area;

c) an optic assembly positioned with respect to the imaging assembly to focus the reflected illumination from the target area onto the photosensor array;

d) an illumination assembly including a first illumination source energizable to generate illumination having a first range of wavelengths and a second illumination source energizable to generate illumination having a second range of wavelengths, the first range of wavelengths including the first wavelength and not including the second wavelength and the second range of wavelengths including the second wavelength and not including the first wavelength, the first and second illumination sources being positioned to illuminate the target area when actuated;

e) control and selection circuitry electrically coupled to the imaging assembly and the illumination assembly to actuate the imaging assembly and selectively energize the first illumination source to image and decode the first dataform and to actuate the imaging assembly and selectively energize the second illumination source to image and decode the second dataform; and

f) wherein the signal representative of the target area image is a composite video signal and the signal and image processing circuitry further includes;

1) signal processing circuitry receiving the composite video signal and converting a portion of the signal corresponding to an image frame into a set of digital data representative of an image of the target area, the set of digital data including a plurality of digital data values corresponding to respective different image pixels of the imaged target area, each of the plurality of digital data values comprising a plurality of bits; and

2) digital signal processing circuitry selectively actuatable to receive the set of digital data generated by the signal processing circuitry, the digital signal processing circuitry including binarization and zoning circuitry to;

i) convert selected digital data values in the plurality of digital data into a set of binary data values, a single bit binary data value being generated for each digital data value;

ii) identify a subset of binary data values of the set of binary data values corresponding to an image of the target object; and

iii) processing the identified subset of binary data values to generate a set of output data.

11. The dataform reader of claim 10 wherein the signal and image processing circuitry further includes cell extraction and decoding circuitry selectively actuatable to operate on the identified subset of binary data values to generate decoded dataform data corresponding to an imaged dataform.

12. The dataform reader of claim 10 wherein the imaging assembly further includes a targeting illumination assembly electrically coupled to the control and selection circuitry, the control and selection circuitry periodically energizing and deenergizing the targeting illumination assembly to provide targeting illumination to aid in aiming the device at a dataform.

13. The dataform reader of claim 12 wherein the targeting illumination assembly is deenergized when either of the first or the second illumination sources are energized.

14. A portable data collection device comprising:

a) a housing defining an interior region;

b) a dataform reader assembly at least partially supported within the housing interior region, the dataform reader assembly including a single two dimensional imaging assembly adapted to independently image and decode first and second overlying dataforms, the first dataform being imaged when illuminated by illumination having a first wavelength and the second dataform being imaged when illuminated by illumination having a second wavelength, the first and second wavelengths being different, the dataform reader assembly including;

1) the single two dimensional imaging assembly including a two dimensional photosensor array, the imaging assembly actuatable to generate a signal representative of an image of a target area of the imaging assembly, the target area image resulting from an illumination pattern received from the target area;

2) the imaging assembly including signal and image processing circuitry for processing and decoding an image of a dataform positioned in the target area;

3) an optic assembly positioned with respect to the imaging assembly to focus the target area image onto the photosensor array;

4) an illumination assembly including a first illumination source energizable to generate illumination having a first range of wavelengths and a second illumination source energizable to generate illumination having a second range of wavelengths, the first range of wavelengths including the first wavelength and not including the second wavelength and the second range of wavelengths including the second wavelength and not including the first wavelength, the first and second illumination sources being positioned to illuminate the target area when actuated, the first illumination source generating illumination having a spectral output centered about a wavelength in the visible spectrum; and

5) control and selection circuitry electrically coupled to the imaging assembly and the illumination assembly to actuate the imaging assembly and selectively energize the first illumination source to image and decode the first dataform and to actuate the imaging assembly and selectively energize the second illumination source to image and decode the second dataform, the second illumination source being deenergized while the first illumination source is energized and the first illumination source being deenergized while the second illumination source is energized.

15. The portable data collection device of claim 14 wherein the second illumination source illuminates the target area with illumination having a spectral output centered about a wavelength in the ultraviolet spectrum.

16. The portable data collection device of claim 14 wherein the first illumination source comprises red light emitting diodes.

17. The portable data collection device of claim 16 wherein the first illumination source illuminates the target area with illumination having a spectral output centered about a wavelength of substantially 660 nanometers.

18. The portable data collection device of claim 14 wherein the second illumination source illuminates the target area with illumination having wavelengths in the ultraviolet spectrum.

19. The portable data collection device of claim 18 wherein the second illumination source illuminates the target area with illumination having a spectral output centered about a wavelength of substantially 254 nanometers.

20. The portable data collection device of claim 18 wherein the second illumination source comprises an ultraviolet lamp.

21. The portable data collection device of claim 14 wherein the optics assembly includes a ultraviolet light filter to prevent illumination having wavelengths in the ultraviolet spectrum from being focused onto the photosensor array.

22. The portable data collection device of claim 14 wherein the two dimensional photosensor array, the optics assembly and the illumination assembly are supported by a modular housing, the photosensor array being supported within an internal region of the modular housing.

23. A portable data collection device comprising:

a) a housing defining an interior region;

b) a dataform reader assembly at least partially supported within the housing interior region, the dataform reader assembly including a single two dimensional imaging assembly adapted to independently image and decode first and second overlying dataforms, the first dataform being imaged when illuminated by illumination having a first wavelength and the second dataform being imaged when illuminated by illumination having a second wavelength, the first and second wavelengths being different, the dataform reader assembly including;

1) the single two dimensional imaging assembly including a two dimensional photosensor array, the imaging assembly actuatable to generate a signal representative of an image of a target area of the imaging assembly, the target area image resulting from an illumination pattern received from the target area;

2) the imaging assembly including signal and image processing circuitry for processing and decoding an image of a dataform positioned in the target area;

3) an optic assembly positioned with respect to the imaging assembly to focus the target area image onto the photosensor array;

4) an illumination assembly including a first illumination source energizable to generate illumination having a first range of wavelengths and a second illumination source energizable to generate illumination having a second range of wavelengths, the first range of wavelengths including the first wavelength and not including the second wavelength and the second range of wavelengths including the second wavelength and not including the first wavelength, the first and second illumination sources being positioned to illuminate the target area when actuated; and

5) control and selection circuitry electrically coupled to the imaging assembly and the illumination assembly to actuate the imaging assembly and selectively energize the first illumination source to image and decode the first dataform and to actuate the imaging assembly and selectively energize the second illumination source to image and decode the second dataform; and

c) wherein the signal representative of the target area image is a composite video signal and the signal and image processing circuitry further includes;

1) signal processing circuitry receiving the composite video signal and converting a portion of the composite video signal corresponding to an image frame into a set of digital data representative of an image of the target area, the set of digital data including a plurality of digital data values corresponding to respective different image pixels of the imaged target area, each of the plurality of digital data values comprising a plurality of bits; and

2) digital signal processing circuitry selectively actuatable to receive the set of digital data generated by the signal processing circuitry, the digital signal processing circuitry including binarization and zoning circuitry to;

i) convert selected digital data values in the plurality of digital data into a set of binary data values, a single bit binary data value being generated for each digital data value;

ii) identify a subset of binary data values of the set of binary data values corresponding to an image of the target object; and

iii) process the identified subset of binary data values to generate a set of output data.

24. The portable data collection device of claim 23 wherein the signal and image processing circuitry further includes cell extraction and decoding circuitry selectively actuatable to operate on the identified subset of binary data values to generate decoded dataform data corresponding to an imaged dataform.

25. The portable data collection device of claim 23 wherein the imaging assembly includes a targeting illumination assembly electrically coupled to the control and selection circuitry, the control and selection circuitry periodically energizing and deenergizing the targeting illumination assembly to provide targeting illumination to aid in aiming the device at a dataform.

26. The portable data collection device of claim 25 wherein the targeting illumination assembly is deenergized when either of the first or the second illumination sources are energized.