CAMERA SYSTEM WITH MULTIPLE PIXEL ARRAYS ON A CHIP

• US 20090135245A1
• Filed: 11/25/2008
• Published: 05/28/2009
• Est. Priority Date: 11/27/2007
• Status: Active Grant

• Current Assignee: CapsoVision, Inc.
• Original Assignee: CapsoVision, Inc.
• Inventors: Wang, Kang-Huai, Luo, Jiafu, Wilson, Gordon C.
• Granted Patent: US 9,118,850 B2
• Time in Patent Office: Days
• US Class Current: 348/36
• CPC Class Codes: A61B 1/041 Capsule endoscopes for imaging
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 25/41 Extracting pixel data from a plurality of image sensors simultaneously picking up an image, e.g. for increasing the field of view by combining the outputs of a plurality of sensors
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components

Abstract

A camera system uses one or more image sensor IC chips each having multiple pixel arrays on the same semiconductor substrate (i.e., “multiple pixel arrays on a chip”). In one embodiment, such a camera system includes: (a) optical components that create multiple images in close physical proximity of each other (e.g., within a few millimeters or centimeters); and (b) a single sensor substrate (“chip”) containing multiple 2-dimensional pixel arrays that are aligned to capture these multiple images, so as to convert the multiple images into electrical signal. The pixel arrays can be manufactured using a CCD or a CMOS compatible process. For manufacturing reasons, such a chip is typically two centimeters or less on a side. However, large chips can also be made. Optional electronic components for further signal processing of the captured images may be formed either on the sensor chip (i.e., in a “system-on-a-chip” implementation), or in a separate back-end application specific integrated circuit (ASIC). In addition, digital storage components, display elements, and wired or wireless communication links may also be included in any suitable combination to allow review and further processing of the captured images.

Claims

1. A camera apparatus, comprising:

a plurality of optical elements forming a plurality of optical paths each forming a separate image from light entering the camera apparatus;

a plurality of sensor arrays fabricated on a common substrate, each sensor array being positioned to capture a corresponding one of the images; and

one or more readout circuits coupled to the sensor arrays for reading from the sensor array electrical signals representing the images captured at the coupled sensor array.

2. A camera apparatus as in claim 1, wherein the readout circuits are formed on the common substrate.

3. A camera apparatus as in claim 2, wherein the readout circuits are formed at a central location on the common substrate, and wherein the sensor arrays are formed at positions along the periphery of the readout circuits.

4. A camera apparatus as in claim 2, wherein a timing and control circuit for controlling the readout circuits and the sensor arrays is formed on the common substrate.

5. A camera apparatus as in claim 1, wherein the common substrate comprises a semiconductor substrate.

6. A camera apparatus as in claim 5, wherein the sensor array comprises CMOS pixels.

7. A camera apparatus as in claim 5, wherein the sensor array comprises CCD pixels.

8. A camera apparatus as in claim 1, wherein the optical paths each comprise an optical subsystem, each optical subsystem having a field of view greater than a predetermined angle, and wherein the optical systems are positioned to be the predetermined angle apart.

9. A camera apparatus as in claim 8, wherein the fields of view of the optical subsystems cover a horizontal view greater than 180°

.

10. A camera apparatus as in claim 8, wherein the fields of view of the optical subsystems cover a horizontal view substantially equal to 360°

.

11. A camera apparatus as in claim 8, further comprising an image processor combining the electrical signals from the sensor arrays to form an image covering the fields of view of the optical subsystems.

12. A camera apparatus as in claim 8, wherein predetermined angle is substantially 90°

.

13. A camera apparatus as in claim 1, further comprising one or more multiplexers provided between the sensor arrays and the readout circuits, such that one or more of the readout circuits are each receiving electrical signals from more than one sensor array.

14. A camera apparatus as in claim 1, wherein the electrical signals from each sensor array is provided to a corresponding one of the readout circuits.

15. A camera apparatus as in claim 1, further comprising a cover glass provided on a surface of the common substrate.

16. A camera apparatus as in claim 1, wherein the optical elements are positioned such that the images are aligned substantially on an image plane.

17. A camera apparatus as in claim 1, further comprising a housing in the form of a swallowable capsule for the camera apparatus.

18. A camera apparatus as in claim 17, further comprising an image processor receiving the electrical signals of the optical subsystems for constructing an image that combines the images captured by the sensor arrays.

19. A camera apparatus as in claim 18, wherein the image processor is provided in an application-specific integrated circuit.

20. A camera apparatus as in claim 19, wherein the common substrate and the application-specific integrated circuit are mounted on a printed circuit board.

21. A camera apparatus as in claim 17, further comprises a light source and a window through which light from the light source can pass to provide illumination on a subject of which an image is desired.

22. A camera apparatus as in claim 17, further comprising a digital storage component for storing data representative of the captured images.

23. A camera apparatus as in claim 17, further comprising a display element.

24. A camera apparatus as in claim 17, further comprising a transmission element for transmitting data representative of the captured images.

25. A camera apparatus as in claim 24, wherein the transmission element supports wireless communication.

26. A camera apparatus as in claim 17, further comprises an image compression circuit.

27. A camera apparatus as in claim 17, further comprising a power source for powering the camera apparatus.

28. A camera apparatus as in claim 1, wherein the electrical signals are digitized.

29. A camera apparatus as in claim 1, wherein the optical elements are held together within a lens holder.

30. A camera apparatus as in claim 1, wherein the optical elements are enclosed by a lens barrel having a bore for optical elements of each optical path.

31. A camera apparatus as in claim 30, further comprises a baffle on top of the lens barrel,

32. A camera apparatus as in claim 1, wherein the optical elements are organized into subsystems, each subsystem comprising a negative-power lens element and a positive-power triplet.

33. A camera apparatus as in claim 32, wherein the optical elements compensate for chromatic aberration.

34. A camera apparatus as in claim 33, wherein the optical elements are organized to provide a folded inverse telephoto lens.

35. A method for providing a panoramic image in a compact camera, comprising:

forming a plurality of optical paths from a plurality of optical elements, each optical path forming a separate image from light entering the camera;

capturing the images using a plurality of sensor arrays fabricated on a common substrate, each sensor array being positioned to capture a corresponding one of the images;

reading out image data from the sensor arrays representing the images captured at the sensor arrays; and

processing the image data to provide the panoramic image.

36. A method as in claim 35, wherein the image data from the sensor arrays are read out by readout circuits formed on the common substrate.

37. A method as in claim 36, wherein the readout circuits are formed at a central location on the common substrate, and wherein the sensor arrays are formed at positions along the periphery of the readout circuits.

38. A method as in claim 36, further comprising controlling the readout circuits and the sensor arrays by a timing and control circuit formed on the common substrate.

39. A method as in claim 35, wherein the common substrate comprises a semiconductor substrate.

40. A method as in claim 39, wherein the sensor array comprises CMOS pixels.

41. A method as in claim 39, wherein the sensor array comprises CCD pixels.

42. A method as in claim 35, further comprising organizing the optical paths each into an optical subsystem, each optical subsystem having a field of view greater than a predetermined angle, and wherein the optical systems are positioned to be the predetermined angle apart.

43. A method as in claim 42, wherein the fields of view of the optical subsystems cover a horizontal view greater than 180°

.

44. A method as in claim 42, wherein the fields of view of the optical subsystems cover a horizontal view substantially equal to 360°

.

45. A method as in claim 42, processing the image data comprises combining, in an image processor, image from the sensor arrays to form an image covering the fields of view of the optical subsystems.

46. A method as in claim 42, wherein predetermined angle is substantially 90°

.

47. A method as in claim 35, wherein reading out image data comprises multiplexing a read out circuit to receive image data from more than one sensor array.

48. A method as in claim 35, wherein the image data from each sensor array is provided to a corresponding readout circuit.

49. A method as in claim 35, further comprising providing a cover glass over a surface of the common substrate.

50. A method as in claim 35, further comprising positioning the optical elements such that the images are aligned substantially on an image plane.

51. A method as in claim 35, wherein the camera is housed in a swallowable capsule.

52. A method as in claim 51, further comprising providing an image processor to receive image data from the optical subsystems for constructing an image that combines the images captured by the sensor arrays.

53. A method as in claim 52, wherein the image processor is provided in an application-specific integrated circuit.

54. A method as in claim 53, further comprising mounting the common substrate and the application-specific integrated circuit on a printed circuit board.

55. A method as in claim 51, further comprises providing a light source and a window through which light from the light source can pass to provide illumination on a subject of which an image is desired.

56. A method as in claim 51, further comprising storing data representative of the captured images in a digital storage component.

57. A method as in claim 51, further comprising providing a display element inside the housing.

58. A method as in claim 51, further comprising transmitting data representative of the captured images to an external receiver.

59. A method as in claim 58, wherein the transmission is over wireless communication.

60. A method as in claim 51, further comprises compressing the panoramic image in an image compression circuit.

61. A method as in claim 51, further comprising power the camera by an on-board power source.

62. A method as in claim 35, wherein the image data are digitized.

63. A method as in claim 35, further comprising holding the optical elements together within a lens holder.

64. A method as in claim 35, further comprising enclosing the optical elements of each optical path in a bore of a lens barrel.

65. A method as in claim 64, further comprises providing a baffle on top of the lens barrel,

66. A method as in claim 35, further comprising organizing the optical elements into subsystems, each subsystem comprising a negative-power lens element and a positive-power triplet.

67. A method as in claim 66, wherein the optical elements compensate for chromatic aberration.

68. A method as in claim 66, wherein the optical elements are organized to provide a folded inverse telephoto lens.

69. An integrated circuit, comprising:

a plurality of sensor arrays fabricated on a common substrate, each sensor array being positioned to capture an image to be projected thereon; and

one or more readout circuits coupled to the sensor arrays for reading from the sensor array electrical signals representing the images captured at the coupled sensor array.

70. An integrated circuit as in claim 69, wherein the readout circuits are formed on the common substrate.

71. An integrated circuit as in claim 70, wherein the readout circuits are formed at a central location on the common substrate, and wherein the sensor arrays are formed at positions along the periphery of the readout circuits.

72. An integrated circuit as in claim 70, wherein a timing and control circuit for controlling the readout circuits and the sensor arrays is formed on the common substrate.

73. An integrated circuit as in claim 69, wherein the common substrate comprises a semiconductor substrate.

74. An integrated circuit as in claim 73, wherein the sensor array comprises CMOS pixels.

75. An integrated circuit as in claim 73, wherein the sensor array comprises CCD pixels.

76. An integrated circuit as in claim 69, wherein the sensors arrays are 90°

apart.

77. An integrated circuit as in claim 69, wherein the sensors arrays are 180°

apart.

78. An integrated circuit as in claim 69, wherein the sensors arrays are 360°

apart.

79. An integrated circuit as in claim 69, further comprising one or more multiplexers provided between the sensor arrays and the readout circuits, such that one or more of the readout circuits are each receiving electrical signals from more than one sensor array.

80. An integrated circuit as in claim 69, wherein the electrical signals from each sensor array is provided to a corresponding one of the readout circuits.

81. An integrated circuit as in claim 69, further comprising a cover glass provided on a surface of the common substrate.

82. An integrated circuit as in claim 69, further comprises an image processing circuit.

83. An integrated circuit as in claim 69, further comprises an image compression circuit.

84. An integrated circuit as in claim 69, wherein the electrical signals are digitized.

85. An integrated image sensor to be operationally coupled to a plurality of optical components, comprising:

a plurality of pixel arrays formed on a single substrate, each pixel array being positioned for sensing an image in a field of view of a corresponding one of the optical components; and

a processing circuit formed on the single substrate for processing the images sensed by the pixel arrays.

86. The integrated image sensor according to claim 85, wherein a portion of the processing circuit resides between two pixel arrays.

87. The integrated image sensor according to claim 85, wherein a lateral dimension of the integrated image sensor is no more than 20% larger than the total lateral extent of the pixel arrays along a common axis.

88. The integrated image sensor according to claim 85, wherein the integrated image sensor has lateral dimensions that are no more than 20% larger than the total lateral extent of the pixel arrays along each of two axes that are perpendicular to each other.

89. The integrated image sensor according to claim 85, wherein the pixel arrays share a common on-chip digital output interface.

90. The integrated image sensor according to claim 85, wherein optical axes in object space of at least two of the optical components are not parallel.

91. The integrated image sensor according to claim 90, wherein the optical axes are disposed at substantially 90°

angles.

92. The integrated image sensor according to claim 91, wherein the fields-of-view of the optical components overlap so that the composite field of view substantially comprises a 360°

panorama.