COLOR BAR CODE TAG READER WITH LIGHT-EMITTING DIODES

• US 3,684,868 A
• Filed: 10/29/1970
• Issued: 08/15/1972
• Est. Priority Date: 10/29/1970
• Status: Expired due to Term

• Current Assignee: Glenn W. Robison, John B. Christie, Raymond C. Runquist Jr
• Original Assignee: Glenn W. Robison, John B. Christie, Raymond C. Runquist Jr
• Inventors: Christie, John B., Robison, Glenn W., Runquist, Raymond C. Jr.
• Primary Examiner(s): Cook, Daryl W.
• Application Number:
  US05/085,076
• Time in Patent Office: 656 Days
• Field of Search: 235/61.11E 250/219
• US Class Current: 235/462.04
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G06K 7/12 using a selected wavelength, e.g. to sense red marks and ignore blue marks

Abstract

A color bar code reader used for detecting and reading recorded indicia having different and distinct light reflective characteristics; i.e., being manifested in the form of colored bars. The reader utilizes a photosensor and two light-emitting diodes, each having a particular output wavelength. The particular embodiment disclosed utilizes a gallium arsenide diode which emits infrared light at 9,000 Angstroms and a gallium arsenide phosphide diode which emits red light at 6,600 Angstroms. In operation, the two light-emitting diodes are alternately pulsed, with the outputs of each being directed an the recorded indicia. A lens system focuses the light-emitting diode radiation onto the recorded indicia. Depending upon the particular colored indicia being utilized, a certain amount of light is reflected, or not reflected, by the colored indicia back to the color bar code reader, where the radiation is concentrated by the lens system for transmission to the solid state photosensor. The photosensor generates a signal proportional to the reflected light which is related to the original light source. Circuitry determines the particular color which reflected the returned light. The generated photosensor signals, which are analog in nature, are processed and digitized by circuitry for a determination of the color represented and are then transmitted to some record keeper. The particular colors utilized with the present invention are white, green, and black, which are recorded on a record medium in the form of bars.

Claims

1. A detecting and identification system for use with a record medium containing information in the form of coded areas having different radiation-reflecting coefficients, the system comprising:

a plurality of radiation-emitting sources;

timing means for energizing said radiation-emitting sources;

means for concentrating and directing the output of said radiation-emitting sources onto said coded areas, whereby the output of said radiation-emitting sources is reflected according to the radiation-reflecting coefficient of said coded areas;

a radiation detector for sensing the reflected radiation and generating signals proportional to the amount of the reflected radiation; and

circuit means for decoding said generated signals;

said radiation sources comprising first and second lightemitting diodes, one of which radiates red light and the other of which radiates infrared light, and said radiation detector comprising a photosensor.

2. A system according to claim 1 wherein said coded areas consist of a plurality of contiguous and adjacent colored bars of first, second, and third colors, further including the requirement that adjacent colored bars are never of the same color, said first color reflecting both infrared and red light, said second color essentially absorbing all infrared and red light, and said third color reflecting said infrared light and essentially absorbing all red light.

3. A system according to claim 2 wherein said circuit means for decoding includes first and second sampling circuits responsive to said generated signals, said first sampling circuit being turned on when said infrared-light-emitting diode is on and said second sampling circuit being turned on when said red-light-emitting diode is on.

4. A system according to claim 3 in which said first sampling circuit is turned on by said timing means during the middle portion of the on period of said infrared-light-emitting diode and in which said second sampling circuit is turned on by said timing means during the middle portion of the on period of said red-light-emitting diode.

5. A system according to claim 4 wherein said first sampling circuit generates an infrared analog signal proportional to the amount of infrared light detected by said radiation detector and said second sampling circuit generates a red analog signal proportional to the amount of red light detected by said radiation detector.

6. A system according to claim 5 including first circuit means for generating a negative envelope of the infrared analog signal and second circuit means for generating a positive envelope of the red analog signal.

7. A system according to claim 6 including a plurality of subtracting amplifiers for subtracting the negative infrared envelope from the infrared analog signal, so that a negative output is indicative of a black color, for subtracting the positive red envelope signal from the red analog signal, so that a negative output is indicative of a white color, and for subtracting the red analog signal from the infrared signal, so that a negative signal is indicative of a green color.

8. A system according to claim 7 further including means for digitizing the output signals from said subtracting amplifiers.

9. A system according to claim 1 wherein said means for concentrating and directing the output of said radiation emitting source comprises a lens and a reflective cone having an aperture at the extreme end thereof, said lens and said reflective cone being so positioned that the axis of the aperture and the optical axis of the lens lie on the same line.

10. A system according to claim 9 further including a generally elongated housing, said radiation sources, said radiation detector, and said means for amplifying said generated signals being disposed within said housing, said housing terminated at one end by said reflective cone.

11. A system according to claim 9 in which said housing is terminated at its other end by a wire cable.

12. A detecting and identification system for use with a record medium containing information in the form of areas having different light-reflecting coefficients, the system comprising:

a substantially elongated housing terminated at one end by a reflective cone including an aperture at the extreme end thereof;

red- and infrared-light-emitting diodes disposed within said housing;

a photosensor disposed within said housing;

means for alternately controlling the output of said red- and infrared-light-emitting diodes disposed within said housing;

an optical lens disposed within said housing for concentrating light emitted from said red- and infrared-light-emitting diodes and directing the same through the aperture of said reflective cone onto said coded areas, whereby said coded areas reflect a certain portion of the infrared and red light according to their respective light-reflecting coefficients;

a photosensor for sensing the reflected infrared and red light and generating signals proportional to the amount of the reflected infrared and red light;

first circuit means for rEceiving and holding said generated signal corresponding to reflected infrared light;

second circuit means for receiving and holding said generated signal corresponding to said reflected red light; and

third circuit means responsive to said first and second circuit means for decoding said generated signals.