Produce data collector and produce recognition system

• US 6,332,573 B1
• Filed: 11/10/1998
• Issued: 12/25/2001
• Est. Priority Date: 11/10/1998
• Status: Expired due to Term

• Current Assignee: NCR Voyix Corporation
• Original Assignee: NCR Corporation
• Inventors: Ames, Stephen J., Seevers, Daniel B., Aleshire, Rex A., Tang, Hong, Gu, Yeming, Spencer, Michael A., Collins, Jr., Donald A., Treptau, Jeffrey P.
• Primary Examiner(s): Frech, Karl D.
• Assistant Examiner(s): St. Cyr, Daniel
• Application Number:
  US09/189,783
• Time in Patent Office: 1,141 Days
• Field of Search: 359/869, 359/863, 359/850, 235/462.06, 235/462.01, 235/462.11, 235/462.14, 235/462.41, 235/462.42
• US Class Current: 235/462.06
• CPC Class Codes: G06V 10/147 Details of sensors, e.g. sensor lenses fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19
• CPC Class Codes: G06V 20/68 Food, e.g. fruit or vegetables
• CPC Class Codes: G07G 1/0054 with control of supplementary check-parameters, e.g. weight or number of articles

Abstract

A produce data collector and produce recognition system which illuminates a produce item with substantially uniform light to enhance the accuracy of collected produce data and subsequent identification of the produce item as part of a transaction in a transaction establishment. The produce data collector includes a light source for illuminating the produce item with substantially uniform light during the transaction, a light separating element for splitting light collected from the produce item into a plurality of different light portions having different wavelengths, a detector for converting energy in the plurality of light portions into a plurality of electrical signals, and control circuitry which digitizes the plurality of electrical signals to produce a digital spectrum from the produce item which contains information to identify the produce item for the purpose of determining its unit price.

Claims

1. A produce data collector for processing a produce item as part of a transaction in a transaction establishment comprising:

a light source for illuminating the produce item with substantially uniform light during the transaction including a plurality of matched LEDs which collectively provide substantially white light with substantial spectral uniformity;

a light separating element for splitting light collected from the produce item into a plurality of different light portions having different wavelengths including a linear variable filter;

a detector for converting energy in the plurality of light portions into a plurality of electrical signals; and

control circuitry which digitizes the plurality of electrical signals to produce a digital spectrum from the produce item which contains information to identify the produce item for the purpose of determining its unit price.

2. The produce data collector as recited in claim 1, wherein the detector comprises:

an array of photodetectors for converting energy in the plurality of light portions into a plurality of electrical signals.

3. The produce data collector as recited in claim 1, wherein the control circuitry comprises:

an analog-to-digital (A/D) convertor.

4. The produce data collector as recited in claim 1, further comprising:

a color balancing filter for balancing spectral throughput from the LEDs and increasing a signal-to-noise ratio of the control circuitry.

5. The produce data collector as recited in claim 1, further comprising:

a light source sensor for monitoring the LEDS for variation in intensity and for producing signals indicative of the intensity;

wherein the control circuitry varies drive current to each LED to compensate for the variation in intensity.

6. The produce data collector as recited in claim 1, further comprising:

an ambient light sensor for sensing intensity of ambient light and for producing signals indicative of the intensity;

wherein the control circuitry turns on the LEDs after ambient light intensity has fallen to a minimum level indicative of placement of the produce item in a data collection position.

7. The produce data collector as recited in claim 1, further comprising:

a shutter for obscuring ambient light;

wherein the control circuitry opens and closes the shutter to take reference ambient light readings.

8. The produce data collector as recited in claim 7, wherein the shutter comprises:

a polymer dispersed liquid crystal (PDLC).

9. The produce data collector as recited in claim 7, wherein the shutter comprises:

a door; and

a motor for moving the door to an open position and to a closed position.

10. The produce data collector as recited in claim 1, further comprising:

a housing containing a first aperture through which the light for illuminating the produce item and the light collected from the produce item pass.

11. The produce data collector as recited in claim 10, wherein the LEDs provide uniform luminosity across the aperture.

12. The produce data collector as recited in claim 10, wherein the plurality of LEDS are arranged around and substantially equidistantly from a center line through the aperture.

13. The produce data collector as recited in claim 10, wherein the aperture is no larger in area than about ¾

inch by ¾

inch.

14. The produce data collector as recited in claim 10, wherein the housing comprises:

a window in the aperture.

15. The produce data collector as recited in claim 14, wherein the housing further comprises:

an anti-reflective coating on an inner side of the window which minimizes a portion of the light for illuminating the produce item which reflects from the inner side of the window.

16. The produce data collector as recited in claim 10, further comprising:

a number of mirrors within the housing for directing the collected light to the light separating element.

17. The produce data collector as recited in claim 16, wherein the mirrors comprise:

a first mirror oriented at about a forty-five degree angle for re-directing the collected light from a first direction to a second direction at about ninety degrees from the first direction; and

a second mirror oriented at about a forty-five degree angle for re-directing the collected light from the second direction to a third direction towards the light separating element at about ninety degrees from the second direction.

18. The produce data collector as recited in claim 17, wherein the first and second mirrors comprise planar mirrors.

19. The produce data collector as recited in claim 17, wherein one of the first and second mirrors also mixes the collected light to produce equalized light of average reflected illumination.

20. The produce data collector as recited in claim 19, wherein the one mirror comprises:

an optical element having a inner concave inner surface and a planar surface; and

a textured reflective layer on the planar surface which diffuses and scatters the collected light;

wherein the inner concave inner surface converges scattered collected light.

21. The produce data collector as recited in claim 20, wherein the optical element is made of molded transparent acrylic.

22. The produce data collector as recited in claim 20, wherein the textured reflective layer comprises enhanced aluminum.

23. The produce data collector as recited in claim 10, further comprising:

a baffle within the housing between the light source and the light separating element for minimizing an amount of the light from the light source which is directly incident upon the light separating element.

24. The produce data collector as recited in claim 23, wherein the baffle comprises:

a plurality of adjacent chambers, including a first chamber closest to the light source and a second chamber farthest away from the light source;

wherein the light separating element is located in the second chamber.

25. The produce data collector as recited in claim 10, further comprising:

a mount for the light source within the housing which anchors the light source and which orients the light source in a position and orientation sufficient to provide uniform luminosity illumination across the aperture.

26. The produce data collector as recited in claim 10, wherein the light separating element comprises:

a first end for processing a first wavelength of the collected light and a second end for processing a second wavelength of the collected light shorter than the first wavelength;

wherein the first end is aligned with a center of the aperture.

27. A produce data collector for processing a produce item as part of a transaction in a transaction establishment comprising:

a housing containing an aperture;

a window in the aperture;

a plurality of light emitting diodes (LEDs) within the housing which collectively produce substantially white light with substantial spectral uniformity for illuminating the produce item as it rests upon the window during the transaction;

a mount for the LEDS within the housing which anchors the LEDs and which orients the LEDs in circular fashion and around and substantially equidistantly from a center line through the aperture in an orientation sufficient to provide uniform luminosity illumination across the window;

a linear variable filter (LVF) within the housing for splitting light collected from the produce item into a plurality of different light portions having different wavelengths;

a number of mirrors within the housing for directing the collected light to the LVF;

a baffle within the housing between the LEDs and the LVF for shielding the LVF from the light from the LEDs; and

a detector within the housing for converting energy in the plurality of light portions into a plurality of electrical signals which contain information to identify the produce item for the purpose of determining its unit price, including a photodetector array.

28. A produce recognition system for processing a produce item as part of a transaction in a transaction establishment comprising:

a checkout station for completing the transaction;

a produce data collector in the checkout station including

a plurality of light emitting diodes (LEDs) within the housing which collectively produce substantially white light with substantial spectral uniformity for illuminating the produce item with substantially uniform light as it rests upon the window during the transaction;

a linear variable filter (LVF) for splitting light collected from the produce item into a plurality of different light portions having different wavelengths;

a detector for converting energy in the plurality of light portions into a plurality of electrical signals;

control circuitry within the checkout station which digitizes the plurality of electrical signals to produce a digital spectrum from the produce item;

a database of reference digital spectra; and

a computer within the checkout station and coupled to the control circuitry and the database which compares the digital spectrum from the produce item with the reference digital spectra to identify the produce item for the purpose of determining its unit price and which adds the produce item to the transaction.

29. The system as recited in claim 28, wherein the computer identifies a number of likely choices for the produce item, displays the choices, and records selection of one of the choices by an operator.

30. The system as recited in claim 28, wherein the produce data collector weighs less than about eight ounces.

31. The system as recited in claim 28, wherein the produce data collector further comprises:

a housing containing a window upon which the produce item is placed;

wherein the window has an area which is less than about ¾

of an inch by ¾

of an inch.

32. A system for processing a produce item as part of a transaction in a transaction establishment comprising:

a checkout station for completing the transaction;

a produce data collector in the checkout station including

a plurality of light emitting diodes (LEDs) within the housing which collectively produce substantially white light with substantially spectral uniformity for illuminating the produce item with substantially uniform light as it rests upon the window during the transaction;

a linear variable filter (LVF) for splitting light collected from the produce item into a plurality of different light portions having different wavelengths;

a detector for converting energy in the plurality of light portions into a plurality of electrical signals;

control circuitry within the checkout station which digitizes the plurality of electrical signals to produce a digital spectrum from the produce item;

a first database of reference digital spectra;

a second database of price information correlated to item identification information;

a scale in the checkout station for providing weight information from the produce item; and

a computer within the checkout station and coupled to the control circuitry, the first and second databases, and the scale, which compares the digital spectrum from the produce item with the reference digital spectra in the first database to determine item identification information for the produce item, which obtains unit price information from the second database using the item identification information for the item, and which determines a price for the produce item from the unit price information and the weight information, and which adds the price of the produce item to the transaction.

33. A method of identifying a produce item as part of a transaction in a transaction establishment comprising the steps of:

(a) illuminating the produce item with substantially uniform white light with substantial spectral uniformity during the transaction by a plurality of matched light emitting diodes (LEDs) arranged in circular fashion and substantially equidistantly from the produce item and oriented at angles sufficient to concentrate substantially all of the light from the LEDs at the produce item;

(b) splitting light collected from the produce item into a plurality of different light portions having different wavelengths by a linear variable filter (LVF);

(c) converting energy in the plurality of light portions into a plurality of electrical signals;

(d) digitizing the plurality of electrical signals to produce a digital spectrum from the produce item; and

(e) comparing the digital spectrum to reference spectra to identify the produce item.

34. The method as recited in claim 33, wherein step b comprises the substep of:

(b-1) locating a first end of the LVF which processes a first wavelength of the collected light in an optical path along a center line through an aperture through which the light for illuminating the produce item and ambient light pass.

35. The method as recited in claim 33, wherein step b comprises the substep of:

(b-1) locating a first end of the LVF which processes red wavelengths of the collected light in an optical path along a center line through an aperture through which the light for illuminating the produce item and ambient light pass.

36. The method as recited in claim 33, wherein step (c) comprises the substep of:

(c-1) converting energy in the plurality of light portions into a plurality of electrical signals by an array of photodetectors.

37. The method as recited in claim 33, wherein step (d) comprises the substep of:

(d) digitizing the plurality of electrical signals by an analog-to-digital (A/D) convertor.

38. The method as recited in claim 33, further comprising the step of:

(f) balancing spectral throughput from the light source.

39. The method as recited in claim 33, further comprising the steps of:

(f) sensing variations in intensity in the light from the light source; and

(g) varying drive current to the light source to compensate for the variations in intensity.

40. The method as recited in claim 33, further comprising the step of:

(f) sensing intensity of ambient light before step (a).

41. The method as recited in claim 40, wherein step (a) comprises the substep of:

(a-1) illuminating the produce item with light after the intensity of the ambient light has fallen to a minimum level.

42. The method as recited in claim 33, further comprising the steps of:

(f) taking reference digital spectrum readings before step (a);

(g) storing the reference readings; and

(h) correcting the digital spectrum obtained in step (d) using the reference readings.

43. The method as recited in claim 42, wherein step (f) comprises the substep of:

(f-1) opening and closing a shutter under an aperture through which the light for illuminating the produce item and ambient light pass.

44. The method as recited in claim 43, wherein substep (f-1) comprises the substeps of:

(f-1-A) closing the shutter;

(f-1-B) taking a first reference reading;

(f-1-C) turning on the light source;

(f-1-D) taking a second reference reading;

(f-1-E) opening the shutter;

(f-1-F) taking a third reference reading;

(f-1-G) turning off the light source; and

(f-1-H) taking a fourth reference reading.

45. The method as recited in claim 43, wherein substep (f-1) comprises the substep of:

(f-1-A) energizing and de-energizing a polymer dispersed liquid crystal (PDLC).

46. The method as recited in claim 43, wherein substep (f-1) comprises the substep of:

(f-1-A) energizing a motor to open and close a door coupled to the motor.

47. The method as recited in claim 33, further comprising the step of:

(f) minimizing a portion of the light for illuminating the produce item which reflects from an inner side of a window through which the light for illuminating the produce item and ambient light pass.

48. The method as recited in claim 33, further comprising the step of:

(f) re-directing the collected light from a first direction to a second direction by a number of mirrors.

49. The method as recited in claim 48, further comprising the step of:

(g) mixing the collected light to produce equalized light of average reflected illumination by one of the mirrors.

50. The method as recited in claim 48, further comprising the step of:

(g) minimizing an amount of the light for illuminating the produce item which mixes with the collected light.

51. The method as recited in claim 33, wherein step (e) comprises the substep of:

(e-1) identifying a number of likely choices for the produce item.

52. The method as recited in claim 51, further comprising the steps of:

(f) displaying the choices; and

(h) recording selection of one of the choices by an operator.