Data reader apparatus having an adaptive lens

• US 20070063048A1
• Filed: 09/14/2006
• Published: 03/22/2007
• Est. Priority Date: 09/14/2005
• Status: Active Grant

• Current Assignee: Allan Krauter, Bradford Morse, Dongmin Yang, Ervin Goldfain, Raymond Lia, Richard Newman, Thomas Karpen, Vivian Hunter, William Havens, Ynjiun Wang
• Original Assignee: Allan Krauter, Bradford Morse, Dongmin Yang, Ervin Goldfain, Raymond Lia, Richard Newman, Thomas Karpen, Vivian Hunter, William Havens, Ynjiun Wang
• Inventors: Wang, Ynjiun, Hunter, Vivian, Newman, Richard, Goldfain, Ervin, Krauter, Allan, Karpen, Thomas, Morse, Bradford, Yang, Dongmin, Lia, Raymond, Havens, William
• Application Number:
  US11/521,142
• Publication Number:
  US 20070063048A1
• Time in Patent Office: Days
• US Class Current: 235/462.460
• CPC Class Codes: G06K 7/10702 Particularities of propagating elements, e.g. lenses, mirrors G06K7/10831 takes precedence

Abstract

Systems and methods for making and using handheld data readers comprising one or more fluid lenses. One or more fluid lenses are provided to allow a handheld data reader to perform such operations as reading indicia, including such additional operations as zooming, reorienting a viewing direction, focusing, adjusting an optical axis, and correcting for the effects of motion such as hand jitter. The fluid lens or lenses can be operated for example by applying electrical signals to fluid lenses comprising a plurality of fluids including at least one that is conductive and at least one that is non-conductive.

Claims

1. A data reader for reading an indicium, comprising:

a case configured to be held in a hand of a user of the data reader, said case configured to house components of said data reader, said components comprising;

a lens system for focusing illumination representing an image of said indicum, said lens system comprising a fluid lens;

a fluid lens control module configured to apply a fluid lens control signal to said fluid lens to control an operational parameter thereof;

an image sensor configured to receive said focused illumination representing said image of said indicium;

an image sensor control module configured to operate said image sensor to capture data comprising at least a portion of a frame of image data from said focused illumination representing said image of said indicium; and

a processing module configured to process said at least a portion of said frame of image data to extract therefrom information by the indicium.

2. The data reader for reading an indicium of claim 1, further comprising a temperature sensor for measuring a temperature in a vicinity of said fluid lens.

3. The data reader for reading an indicium of claim 2, wherein said fluid lens control module is configured to apply to said fluid lens a fluid lens control signal based on information output by said temperature sensor.

4. The data reader for reading an indicium of claim 1, wherein said fluid lens is configured to adjust a focal length thereof in response to said fluid lens control signal.

5. The data reader for reading an indicium of claim 1, further comprising at least one of:

a) a user operated trigger for commanding a read operation to commence;

b) an input configured to accept a command from an external system;

c) an output configured to provide an output datum as output information;

d) a battery;

e) a power supply;

f) a microprocessor with at least one of a memory, a bus, and a direct memory access module;

g) a wireless communication module;

h) an illumination source for illuminating an indicium;

i) an aiming system comprising a laser; and

,

j) a power supply configured to supply at least two signal levels, each signal level causing said fluid lens to assume a distinct focal length.

6. The data reader for reading an indicium of claim 5, wherein said input configured to accept a command from an external system accepts a command from a computer.

7. The data reader for reading an indicium of claim 5, wherein said input configured to accept a command from an external system accepts a command configured to control the operation of said fluid lens.

8. The data reader for reading an indicium of claim 5 wherein said output datum is a selected one of an indication of a good read and a value of said good read.

9. The data reader for reading an indicium of claim 8, further comprising a read termination module that discontinues a read operation upon the occurrence of a good decode.

10. The data reader for reading an indicium of claim 5, wherein said output datum is a parameter of said fluid lens.

11. The data reader for reading an indicium of claim 5, wherein said output datum is a status of said reader.

12. The data reader for reading an indicium of claim 5, wherein said wireless communication module comprises a radio.

13. The data reader for reading an indicium of claim 5, wherein said illumination source provides illumination in the red portion of the spectrum.

14. The data reader for reading an indicium of claim 5, further comprising illumination optics for focusing said illumination on said indicium.

15. The data reader for reading an indicium of claim 5, further comprising an aimer illuminator for identifying an aiming point of said data reader relative to said indicium.

16. The data reader for reading an indicium of claim 15, wherein said aimer illuminator provides illumination in a selected one of the green portion of the illumination spectrum and the red portion of the illumination spectrum.

17. The data reader for reading an indicium of claim 5, wherein said power supply is an inductive boost supply comprising an inductor.

18. The data reader for reading an indicium of claim 5, wherein said at least two signal levels are voltages.

19. The data reader for reading an indicium of claim 5, wherein said power supply is configured to supply a signal comprising a two phase square wave component having a first state and a second state.

20. The data reader for reading an indicium of claim 19, wherein said signal comprising a two phase square wave component has a substantially 50% duty cycle with a repetition rate of greater than 500 Hz.

21. The data reader for reading an indicium of claim 19, wherein said signal comprising a two phase square wave component has a transition time from one of said first state and said second state to the other of said first state and said second state in substantially 50 microseconds or less.

22. The data reader for reading an indicium of claim 19, wherein said first state and said second state have substantially equal and opposite amplitudes.

23. The data reader for reading an indicium of claim 19, wherein said first state and said second state are switched substantially in synchronization with a data collection period of said image sensor.

24. The data reader for reading an indicium of claim 19, wherein said data collection period of said image sensor is an integration period.

25. The data reader for reading an indicium of claim 5, wherein said power supply is controlled to switch a supply signal between a first of said at least two signal levels and a second of said at least two signal levels after a frame of image data is read out.

26. The data reader for reading an indicium of claim 25, wherein said power supply is controlled to switch a supply signal between a first of said at least two signal levels and a second of said at least two signal levels after every frame of image data is read out.

27. The data reader for reading an indicium of claim 1, wherein said fluid lens control module is configured to apply to said fluid lens a fluid lens control signal based on information recorded in a calibration table to control a focal length of said fluid lens.

28. The data reader for reading an indicium of claim 1, wherein said captured data comprises a portion of a total field of view of said image sensor.

29. The data reader for reading an indicium of claim 1, wherein said fluid lens is configured to adjust an optical axis thereof in response to said fluid lens control signal.

30. The data reader for reading an indicium of claim 1, wherein said indicium is a bar code, an optically recognizable character, or a graphical image.

31. The data reader for reading an indicium of claim 30, wherein said indicium is a 1D, 2D, or stacked bar code.

32. The data reader for reading an indicium of claim 30, wherein said indicium is an alphanumeric character, a punctuation mark, or an Optical Character Recognition (OCR) character.

33. A process for focusing a handheld data reader comprising a fluid lens, comprising the steps of:

(a) operating said handheld data reader to acquire an image from a target, said fluid lens of said handheld reader configured to operate at a first focal length;

(b) assessing the acquired image to determine whether the image is suitably focused;

(c) in the event that the image is suitably focused, processing the image to retrieve information represented by the image; and

(d) in the event that the image is not suitably focused;

iteratively performing the steps of;

adjusting an operating parameter of said fluid lens to alter an operating focal property of said fluid lens; and

repeating steps (a) and (b) recited hereinabove until condition (c) is attained.

34. The process for focusing a handheld data reader comprising a fluid lens of claim 33, wherein said operating focal property is focal length.

35. The process for focusing a handheld data reader comprising a fluid lens of claim 33, wherein said first focal length is selected from a calibration table.

36. The process for focusing a handheld data reader comprising a fluid lens of claim 33, further comprising the step of using a temperature reading taken in a vicinity of said fluid lens to correct a focus of said fluid lens.

37. A process for focusing a handheld data reader comprising a fluid lens, comprising the steps of:

(a) operating said handheld data reader using a first focal length to acquire an image from a target comprising an encoded indicium;

(b) attempting to retrieve encoded information from said acquired image;

(c) in the event that suitable information is retrieved from said image, reporting said information and terminating said process; and

(d) in the event that suitable information is not retrieved from said image;

iteratively performing the steps of;

adjusting said fluid lens to operate at a focal length different from a focal length previously employed;

repeating step (a) using said different focal length; and

repeating step (b);

until a selected one of the following is true;

condition (c) is attained;

the iterative steps (a) and (b) are repeated until at least one of a predetermined number of iterations and a predetermined time is reached.

38. The process for focusing a handheld data reader comprising a fluid lens of claim 37, wherein in step (a), said image from a target comprising an encoded indicium is an image comprising pixels representing less than a full frame of data.

39. The process for focusing a handheld data reader comprising a fluid lens of claim 37, wherein the step of adjusting said fluid lens to operate at a focal length different from a focal length previously employed is accomplished by accessing a calibration table.

40. A process for calibrating a handheld data reader apparatus comprising a fluid lens responsive to a control signal, comprising the steps of:

(a) operating said handheld data reader to acquire an image from a target separated from said handheld data reader by a first distance;

(b) providing a control signal to control a focus of said fluid lens to within an acceptable range;

(c) recording, for later retrieval and use, a data point comprising at least one of

(i) a metric related to said first distance, and

(ii) a metric related to the value of said control signal in a non-volatile memory; and

(d) optionally, iteratively repeating steps (a), (b) and (c) to build a calibration table for said handheld reader apparatus, wherein at each repetition of step (a) after the first, said target and said handheld reader apparatus are separated by a distance different from a distance employed in a previous repetition of step (a).

41. The process for calibrating a handheld data reader apparatus comprising a fluid lens responsive to a control signal of claim 40, wherein a calibration is represented by a single data point.

42. The process for calibrating a handheld data reader apparatus comprising a fluid lens responsive to a control signal of claim 40, wherein said calibration table comprises at least two data points.

43. The process for calibrating a handheld data reader apparatus comprising a fluid lens responsive to a control signal of claim 40, further comprising the steps of:

measuring a quantity representative of a temperature in a vicinity of said fluid lens during said calibration process; and

recording said measured quantity representative of a temperature in a non-volatile memory for later retrieval and use.

44. A handheld data reader for reading an indicium and comprising a fluid lens having a steerable optical axis, comprising:

a case configured to be held in a hand of a user of the data reader, said case configured to house components of said data reader, said components comprising;

a fluid lens for transmitting light along an optical axis, said fluid lens having a plurality of first electrodes disposed at a first electrical contact region of a fluid responsive to an impressed electric potential, and at least a second electrode disposed at a second electrical contact region of said fluid responsive to an impressed electric potential; and

a fluid lens control module configured to apply at least one of a plurality of fluid lens control signals to at least one of said plurality of first electrodes of said fluid lens to control a direction of an optical axis thereof;

a plurality of sensors operating along at least two non-collinear vectors, said plurality of sensors configured to detect a change in orientation of said handheld data reader;

an optical axis reorientation unit configured to determine at least one control signal calculated to reorient said optical axis of said fluid lens to at least partially correct for said change of orientation of said handheld data reader, said at least one control signal then being applied as an electric potential to at least one of said plurality of first electrodes;

an image sensor configured to receive focused illumination representing an image of said encoded indicium;

an image sensor control module configured to operate said image sensor to capture data comprising at least a portion of a frame of image data from said focused illumination representing said image of said encoded indicium; and

a processing module configured to process said at least a portion of said frame of image data to extract therefrom information encoded by said encoded indicium;

whereby said handheld data reader is configured to at least partially correct for motion thereof when operated in a handheld manner.

45. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, whereby upon motion of said handheld data reader changing the alignment between the encoded indicium and said optical axis by a certain degree, the alignment between said focused illumination received by said image sensor and said image sensor changes by less than said certain degree.

46. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, wherein said change in orientation of said handheld data reader is a change in attitude of said handheld data reader.

47. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, wherein said change in orientation of said handheld data reader is a change in an angular velocity of said handheld data reader about a direction in space.

48. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, wherein said at least a second electrode comprises a plurality of electrodes.

49. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, further comprising a temperature sensor for measuring a quantity representative of a temperature in a vicinity of said fluid lens.

50. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, wherein said fluid lens is further configured to adjust a focal length thereof in response to said fluid lens control signal.

51. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, further comprising at least one of:

a) a user operated trigger for commanding a read operation to commence;

b) an input configured to accept a command from an external system;

c) an output configured to provide an output datum as output information;

d) a battery;

e) a power supply;

f) a microprocessor with at least one of a memory, a bus, and a direct memory access module;

g) a wireless communication module;

h) an illumination source for illuminating an indicium;

i) a power supply configured to supply at least two signal levels, each signal level causing said fluid lens to assume a distinct focal length; and

,

j) an aiming system comprising a laser.

52. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said input configured to accept a command from an external system is configured to accept a command from a computer.

53. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said input configured to accept a command from an external system is configured to accept a command to control an operation of said fluid lens.

54. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said output datum is a selected one of an indication of a good read and a value of said good read.

55. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 54, further comprising a read termination module that discontinues a read operation upon the occurrence of a good read.

56. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said output datum is at least one of a parameter of said fluid lens and a status of said reader.

57. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said wireless communication module comprises a radio.

58. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said illumination source provides illumination in the red portion of the spectrum.

59. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, further comprising illumination optics for focusing said illumination on said indicium.

60. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, further comprising an aimer illuminator for identifying an aiming point of said data reader relative to said indicium.

61. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 60, wherein said aimer illuminator provides illumination in a selected one of the green portion of the illumination spectrum and the red portion of the illumination spectrum.

62. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said power supply is an inductive boost supply comprising an inductor.

63. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said at least two signal levels are voltages.

64. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said power supply is configured to supply a signal comprising a two phase square wave component having a first state and a second state.

65. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 64, wherein said signal comprising a two phase square wave component has a substantially 50% duty cycle with a repetition rate of 5 kHz.

66. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 64, wherein said signal comprising a two phase square wave component has a transition time from one of said first state and said second state to another of said first state and said second state in substantially 10 microseconds or less.

67. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 64, wherein said first state and said second state have substantially equal and opposite amplitudes.

68. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 64, wherein said first state and said second state are switched substantially in synchronization with a data collection period of said image sensor.

69. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 64, wherein said data collection period of said image sensor is an integration period.

70. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 51, wherein said power supply is controlled to switch a supply signal between a first of said at least two signal levels and a second of said at least two signal levels after a frame of image data is read out.

71. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 70, wherein said power supply is controlled to switch a supply signal between a first of said at least two signal levels and a second of said at least two signal levels after every frame of image data is read out.

72. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, wherein said fluid lens control module is configured to apply to said fluid lens a fluid lens control signal based on information recorded in a calibration table to control a focal length of said fluid lens.

73. The handheld data reader for reading an encoded indicium and comprising a fluid lens having a steerable optical axis of claim 44, wherein said captured data comprises a portion of a total field of view of said image sensor.

74. A process for adjusting in real time an optical axis of a handheld data reader comprising a fluid lens, comprising the steps of:

(a) providing a handheld reader comprising;

a case configured to be held in a hand of a user of the data reader, said case configured to house components of said data reader, said components comprising;

a fluid lens for transmitting light along an optical axis, said fluid lens having a plurality of first electrodes disposed at a first electrical contact region of a fluid responsive to an impressed electric potential, and at least a second electrode disposed at a second electrical contact region of said fluid responsive to an impressed electric potential; and

a fluid lens control module configured to apply a plurality of fluid lens control signals to said plurality of first electrodes of said fluid lens to control a direction of an optical axis thereof;

a plurality of sensors operating along at least two non-collinear vectors, said plurality of sensors configured to detect a change in orientation of said handheld data reader;

an optical axis reorientation unit configured to determine at least one control signal calculated to reorient said optical axis of said fluid lens to at least partially correct for said change of orientation of said handheld data reader, said at least one control signal then being applied as an electric potential to at least one of said plurality of first electrodes;

(b) determining a first direction of said optical axis by operation of said fluid lens control module;

(c) determining a first orientation of said handheld data reader by operation of said plurality of sensors operating along at least two non-collinear vectors;

(d) observing a change in orientation of said handheld optical reader from said first orientation to a second orientation;

(e) determining at least one control signal calculated to reorient said optical axis of said fluid lens to overcome said change of orientation of said handheld data reader; and

(f) applying said at least one control signal as an electric potential to at least one of said plurality of first electrodes;

whereby said optical axis of said fluid lens is reoriented to at least partially correct for said change in orientation of said handheld data reader to maintain said optical axis substantially along said first direction irrespective of a change of orientation of said handheld data reader.

75. The process for adjusting in real time an optical axis of a handheld data reader comprising a fluid lens of claim 74, wherein a signal from a user initiates the operation of steps (b) and (c).

76. A process for correlating an operation of a first fluid lens to an operation of a second fluid lens, comprising the steps of:

providing a first calibration relation for said first fluid lens and a second calibration relation for said second fluid lens, each of said first and said second calibration relations having the corresponding optical parameter of said first and said second fluid lenses as one variable and a control signal parameter as another variable;

selecting a value of said optical parameter at which said fluid lenses are to be operated;

extracting from each calibration relation the value of the control signal parameter corresponding to the selected value of said optical parameter, thereby obtaining a first value of said control signal representative of said first fluid lens and a second value of said control signal representative of said second fluid lens when each fluid lens operates at said selected value of said optical parameter; and

determining a difference in value between said first value of said control signal representative of said first fluid lens and said second value of said control signal representative of said second fluid lens when each fluid lens operates at said selected value of said optical parameter;

whereby matched operation of said first fluid lens and said second fluid lens at said selected value of said optical parameter is accomplished by applying a common control signal to both of said first and said second fluid lenses, with the additional application of said difference, accounting for sign, to a selected one of said first and said second lens.

77. The process for correlating an operation of a first fluid lens to an operation of a second fluid lens of claim 76, wherein said calibration relation is a curve.

78. The process for correlating an operation of a first fluid lens to an operation of a second fluid lens of claim 76, wherein said calibration relation is a series of discrete values;

and an intermediate value at which operation is desired is computed.

79. The process for correlating an operation of a first fluid lens to an operation of a second fluid lens of claim 78, wherein said intermediate value at which operation is desired is interpolated.