Method and apparatus for generating a control signal

• US 6,166,370 A
• Filed: 01/14/1998
• Issued: 12/26/2000
• Est. Priority Date: 05/14/1996
• Status: Expired due to Fees

• Current Assignee: Michel Sayag
• Original Assignee: Michel Sayag
• Inventors: Sayag, Michel
• Primary Examiner(s): Lee, John R.
• Application Number:
  US09/007,276
• Time in Patent Office: 1,077 Days
• Field of Search: 250/208.1, 250/221, 250/222.1, 250/208.2, 250/208.3, 250/208.4, 250/208.5, 250/208.6, 250/227.13, 250/227.14, 250/239, 250/216, 250/214.1 , 250/214 R, 356/400, 345/156, 345/157, 345/158, 345/161, 345/163, 345/166, 345/173, 345/177, 345/179, 382/115, 382/116, 382/119, 382/124, 382/125, 382/126, 382/127
• US Class Current: 250/221
• CPC Class Codes: G06F 21/32 using biometric data, e.g. fingerprints, iris scans or voiceprints
• CPC Class Codes: G06F 21/83 input devices, e.g. keyboards, mice or controllers thereof
• CPC Class Codes: G06F 2203/0338 Fingerprint track pad, i.e. fingerprint sensor used as pointing device tracking the fingertip image
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 2211/007 Encryption, En-/decode, En-/decipher, En-/decypher, Scramble, (De-)compress
• CPC Class Codes: G06F 3/021 Arrangements integrating additional peripherals in a keyboard, e.g. card or barcode reader, optical scanner
• CPC Class Codes: G06F 3/0213 Arrangements providing an integrated pointing device in a keyboard, e.g. trackball, mini-joystick for pointing devices integrated in a laptop computer G06F1/169; joysticks G05G9/047; constructional details of pointing devices G06F3/033
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: G07C 9/37 using biometric data, e.g. fingerprints, iris scans or voice recognition

Abstract

A method and apparatus for generating a control signal which corresponds to movement of an object in contact with a first surface are described. The apparatus includes a platen having the first surface. The platen is characterized by a critical angle beyond which light incident upon the first surface is not transmitted. A source of electromagnetic radiation emits electromagnetic radiation through the platen thereby illuminating the object. A detector having a plurality of sectors receives a portion of the electromagnetic radiation diffused by the object and transmitted through the platen beyond the critical angle. The sectors of the detector accumulate charge in response to the incident electromagnetic radiation. Conversion circuitry then converts the charge accumulated in the detector to the control signal, which in a specific embodiment is for controlling the movement of a pointer on a display.

Claims

1. An apparatus for generating a control signal for controlling movement of a first object, the control signal corresponding to movement of a second object in contact with a first surface, the apparatus also being for generating image data representative of the second object, the apparatus comprising:

a platen comprising the first surface;

a source of electromagnetic radiation for emitting electromagnetic radiation through the platen which is diffused by the second object;

a lens for transmitting a portion of the electromagnetic radiation;

a detector for receiving the portion of the electromagnetic radiation and generating charge in response thereto; and

conversion circuitry for converting the charge generated in the detector to the control signal in a first mode of operation, the conversion circuitry also being for generating the image data from the charge generated in the detector in a second mode of operation, the control signal representing a speed and a direction of movement of the first object in the first mode of operation.

2. The apparatus of claim 1 wherein the lens comprises a microsphere lens.

3. The apparatus of claim 1 wherein the detector comprises a photodetector array having a first plurality of pixels, the first plurality of pixels being configurable to form a plurality of sectors.

4. The apparatus of claim 3 wherein the first plurality of pixels are configurable to form four sectors each of which comprises a quadrant of the detector.

5. The apparatus of claim 3 wherein the first plurality of pixels are configurable to generate charge corresponding to a high resolution image of the object.

6. The apparatus of claim 3 wherein the first plurality of pixels are configurable in the first mode of operation to form a first number of sectors, each sector having an output associated therewith, the plurality of pixels also being configurable in the second mode of operation to form a single imaging array having a single output associated therewith.

7. The apparatus of claim 3 wherein the photodetector array is implemented in a single silicon substrate, the apparatus further comprising encryption circuitry for encrypting the charge generated in the photodetector array, the encryption circuitry being implemented in the single silicon substrate with the photodetector array.

8. The apparatus of claim 3 wherein the photodetector array is implemented in a single silicon substrate, the apparatus further comprising a computer interface, the computer interface being implemented in the single silicon substrate with the photodetector array.

9. The apparatus of claim 3 wherein the photodetector array is implemented in a single silicon substrate, the apparatus further comprising an analog-to-digital converter and an external input port for injecting signals into the analog-to-digital converter, the external input port and the analog-to-digital converter being implemented in the single silicon substrate with the photodetector array.

10. The apparatus of claim 1 wherein the second object comprises a fingertip and the control signal is for controlling movement of a pointer on a display in response to the movement of the fingertip on the platen, and wherein the conversion circuitry comprises an analog-to-digital converter and a serial data interface to facilitate compatibility with a computer serial data port.

11. The apparatus of claim 10 wherein the conversion circuitry is further operable to generate a selection signal in response to a sequence of intermittent contacts between the fingertip and the platen, the selection signal being for selecting an item on the display indicated by the pointer.

12. The apparatus of claim 10 further comprising an ultrasonic sensor for taking an echographic cross-section of the fingertip, the echographic cross-section comprising data indicating whether the fingertip is a live human fingertip.

13. The apparatus of claim 1 wherein the detector and the source of electromagnetic radiation are integrated with an injection molded plastic housing comprising the platen.

14. The apparatus of claim 13 wherein the housing further comprises the lens.

15. The apparatus of claim 1 wherein the source of electromagnetic radiation comprises at least one light emitting diode.

16. The apparatus of claim 1 wherein the source of electromagnetic radiation is positioned with respect to the platen such that only the electromagnetic radiation diffused by the second object beyond the critical angle impinges upon the detector.

17. The apparatus of claim 1 wherein the source of electromagnetic radiation is positioned with respect to the platen such that the electromagnetic radiation internally reflects from the platen and impinges upon the detector.

18. The apparatus of claim 1 further comprising a memory for storing data specific to the apparatus.

19. The apparatus of claim 18 wherein the detector and the memory are implemented in a single silicon substrate, and the memory comprises memory which may be configured so that it may not be rewritten.

20. The apparatus of claim 18 wherein the detector and the memory are implemented in a single silicon substrate, and the memory comprises volatile memory.

21. The apparatus of claim 1 wherein the second object defines an area of contact with the platen, the apparatus further comprising means for determining whether the size of the area of contact exceeds a threshold.

22. The apparatus of claim 1 wherein the first surface of the platen has an object plane associated therewith, and the detector has an image plane associated therewith, there being an optical path between the object plane and image plane, the apparatus further comprising a housing within which the detector is enclosed, the housing having an internal surface through which the optical path passes, the internal surface and the lens being part of a demagnifying telecentric lens system.

23. An apparatus for generating image data representative of an object in contact with a first surface, comprising:

a platen comprising the first surface;

a source of electromagnetic radiation for emitting electromagnetic radiation through the platen which is diffused by the object;

a microsphere lens for transmitting a portion of the electromagnetic radiation;

a detector for receiving the portion of the electromagnetic radiation and generating charge in response thereto, the detector being implemented in a single semiconductor substrate; and

circuitry for generating the image data from the charge generated in the detector, the circuitry being implemented in the single semiconductor substrate with the detector;

wherein the microsphere lens is fixed with respect to the detector using an adhesive material having a first index of refraction which is substantially the same as a second index of refraction associated with the microsphere lens.

24. The apparatus of claim 23 wherein the circuitry comprises a computer port interface.

25. The apparatus of claim 23 wherein the circuitry comprises encryption circuitry for encrypting the image data.

26. The apparatus of claim 23 wherein the circuitry comprises memory for storing the image data.

27. The apparatus of claim 23 wherein the circuitry comprises an analog-to-digital converter.

28. The apparatus of claim 23 wherein the circuitry comprises an external signal input port for injecting signals into the analog-to-digital converter.

29. The apparatus of claim 23 wherein the circuitry comprises security circuitry which limits access to the image data.

30. An apparatus for generating image data representative of an object in contact with a surface, comprising:

a platen comprising the surface;

electronic circuitry for generating an image of the object using the platen;

a microsphere lens for transmitting the image generated by the electronic circuitry and the platen; and

a detector for receiving the image via the microsphere lens and generating charge corresponding to the image data in response thereto;

wherein the microsphere lens is fixed with respect to the detector using an adhesive material having a first index of refraction which is substantially the same as a second index of refraction associated with the microsphere lens.

31. An apparatus for generating a control signal for controlling movement of a first object, the control signal corresponding to movement of a second object in contact with a first surface, the apparatus also being for generating image data representative of the second object, the apparatus comprising:

a platen comprising the first surface;

electronic circuitry for generating an image of the second object using the platen;

a lens for transmitting the image generated by the electronic circuitry and the platen;

a detector for receiving the image from the lens and generating charge in response thereto; and

conversion circuitry for converting the charge generated in the detector to the control signal in a first mode of operation, the conversion circuitry also being for generating the image data from the charge generated in the detector in a second mode of operation, the control signal representing a speed and a direction of movement of the first object in the first mode of operation.

32. An apparatus for generating a control signal for controlling movement of a first object, the control signal corresponding to movement of a second object in contact with a first surface, the apparatus also being for generating image data representative of the second object, the apparatus comprising:

a platen comprising the first surface; and

electronic circuitry for generating the control signal using the platen in a first mode of operation, the electronic circuitry also being for generating the image data using the platen in a second mode of operation, the control signal representing a speed and a direction of movement of the first object in the first mode of operation.

33. An apparatus for capturing an image of a fingertip, comprising:

a fingerprint capture device having a platen for contacting the fingertip, the fingerprint capture device also including a microsphere lens for demagnifying the image of the fingertip, and an image sensor for generating charge corresponding to the image of the fingertip; and

a housing having a shape of a hand-held writing implement enclosing the fingerprint capture device, the housing having an aperture through which the fingertip contacts the platen;

wherein the microsphere lens is fixed with respect to the image sensor using an adhesive material having a first index of refraction which is substantially the same as a second index of refraction associated with the microsphere lens.

34. The apparatus of claim 33 wherein the fingerprint capture device comprises a demagnifying telecentric lens system.

35. The apparatus of claim 34 wherein an optical path between the platen and the image sensor is shaped without reflective elements.

36. The apparatus of claim 33 wherein the platen is substantially circular.

37. The apparatus of claim 33 wherein the platen is elliptical.

38. The apparatus of claim 33 wherein the platen is convex.

39. The apparatus of claim 33 wherein the housing comprises a conical section and a cylindrical section, the aperture being in the conical section.

40. The apparatus of claim 33 wherein the platen has a critical angle associated therewith beyond which light incident on the platen is not transmitted, and wherein a surface of the platen is characterized by a convexity as a result of which an optical path between the platen and the image sensor lies substantially beyond the critical angle.

41. The apparatus of claim 33 further comprising a writing implement enclosed within the housing.

42. The apparatus of claim 33 further comprising pointing device electronics enclosed within the housing.

43. The apparatus of claim 33 wherein the housing comprises a structural device which facilitates positioning the fingertip on the platen.

44. The apparatus of claim 33 wherein the lens comprises a microsphere lens.

45. A method for providing an electronic equivalent of a signature, comprising the steps of:

providing an apparatus comprising a fingerprint capture device having a platen, a demagnifying microsphere lens, and an image sensor wherein the microsphere lens is fixed with respect to the image sensor using an adhesive material having a first index of refraction which is substantially the same as a second index of refraction associated with the microsphere lens, the apparatus further comprising a housing having a shape of a hand-held writing implement enclosing the fingerprint capture device, the housing having an aperture;

capturing an image of a user'"'"'s fingertip in contact with the platen through the aperture using the fingerprint capture device;

converting the image to electronic information with the image sensor; and

employing the electronic information as the electronic equivalent of the signature.

46. The method of claim 45 wherein the demagnifying lens comprises a microsphere lens.

47. An apparatus for generating image data representative of an object in contact with a first surface, comprising:

a platen comprising the first surface and a second surface;

a source of electromagnetic radiation for emitting electromagnetic radiation through the platen which is diffused by the object;

a microsphere lens for transmitting a portion of the electromagnetic radiation;

a detector for receiving the portion of the electromagnetic radiation and generating charge in response thereto, the detector being implemented in a single semiconductor substrate; and

circuitry for generating the image data from the charge generated in the detector, the circuitry being implemented in the single semiconductor substrate with the detector;

wherein the microsphere lens and the second surface form a telecentric lens system.

48. The apparatus of claim 47 wherein the circuitry comprises a computer port interface.

49. The apparatus of claim 47 wherein the circuitry comprises encryption circuitry for encrypting the image data.

50. The apparatus of claim 47 wherein the circuitry comprises memory for storing the image data.

51. The apparatus of claim 47 wherein the circuitry comprises an analog-to-digital converter.

52. The apparatus of claim 47 wherein the circuitry comprises an external signal input port for injecting signals into the analog-to-digital converter.

53. The apparatus of claim 47 wherein the circuitry comprises security circuitry which limits access to the image data.

54. An apparatus for generating image data representative of an object in contact with a first surface, comprising:

a platen comprising the first surface and a second surface;

electronic circuitry for generating an image of the object using the platen;

a microsphere lens for transmitting the image generated by the electronic circuitry and the platen; and

a detector for receiving the image via the microsphere lens and generating charge corresponding to the image data in response thereto;

wherein the microsphere lens and the second surface form a telecentric lens system.

55. An apparatus for capturing an image of a fingertip, comprising:

a fingerprint capture device having a platen for contacting the fingertip wherein the platen includes a surface, the fingerprint capture device also including a microsphere lens for demagnifying the image of the fingertip, and an image sensor for generating charge corresponding to the image of the fingertip; and

a housing having a shape of a hand-held writing implement enclosing the fingerprint capture device, the housing having an aperture through which the fingertip contacts the platen;

wherein the microsphere lens and the surface form a telecentric lens system.

56. The apparatus of claim 55 wherein an optical path between the platen and the image sensor is shaped without reflective elements.

57. The apparatus of claim 55 wherein the platen is substantially circular.

58. The apparatus of claim 55 wherein the platen is elliptical.

59. The apparatus of claim 55 wherein the platen is convex.

60. The apparatus of claim 55 wherein the housing comprises a conical section and a cylindrical section, the aperture being in the conical section.

61. The apparatus of claim 55 wherein the platen has a critical angle associated therewith beyond which light incident on the platen is not transmitted, and wherein the surface of the platen is characterized by a convexity as a result of which an optical path between the platen and the image sensor lies substantially beyond the critical angle.

62. The apparatus of claim 55 further comprising a writing implement enclosed within the housing.

63. The apparatus of claim 55 further comprising pointing device electronics enclosed within the housing.

64. The apparatus of claim 55 wherein the housing comprises a structural device which facilitates positioning the fingertip on the platen.

65. A method for providing an electronic equivalent of a signature, comprising the steps of:

providing an apparatus comprising a fingerprint capture device having a platen wherein the platen includes a first surface and second surface, a demagnifying microsphere lens, and an image sensor, wherein the microsphere lens and the second surface form a telecentric lens system, the apparatus further comprising a housing having a shape of a hand-held writing implement enclosing the fingerprint capture device, the housing having an aperture;

capturing an image of a user'"'"'s fingertip in contact with the first surface of the platen through the aperture using the fingerprint capture device;

converting the image to electronic information with the image sensor; and

employing the electronic information as the electronic equivalent of the signature.