Method and apparatus providing pixel storage gate charge sensing for electronic stabilization in imagers

• US 7,626,626 B2
• Filed: 01/13/2006
• Issued: 12/01/2009
• Est. Priority Date: 01/13/2006
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Panicacci, Roger
• Primary Examiner(s): Ye; Lin
• Assistant Examiner(s): VIRANY, LESLIE R
• Application Number:
  US11/331,121
• Publication Number:
  US 20070165123A1
• Time in Patent Office: 1,418 Days
• Field of Search: 348/294, 348/308, 250/208.1
• US Class Current: 348/308
• CPC Class Codes: H04N 25/40 Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/76 Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 25/771 comprising storage means other than floating diffusion
• CPC Class Codes: H04N 3/155 Control of the image-sensor operation, e.g. image processing within the image-sensor

Abstract

An imaging device that stores charge from a photosensor under at least one storage gate. A driver used to operate the at least one storage gate, senses how much charge was transferred to the storage gate. The sensed charge is used to obtain at least one signature of the image scene. The at least one signature may then be used for processing such as e.g., motion detection, auto-exposure, and auto-white balancing.

Claims

1. An imaging device comprising:

a plurality of pixels, each pixel comprising a photosensor and at least a first gate for storing charge from said photosensor when activated by a first control signal; and

a plurality of first circuits, each first circuit being connected to and associated with a respective first set of pixels, each first circuit generating the first control signal on a first control line for all pixels in its respective first set and sensing via the first control line an amount of charge stored under said first gates in the respective first set.

2. The imaging device of claim 1, wherein each pixel further comprises a second gate for storing charge from said photosensor when activated by a second control signal, and

said device further comprises a plurality of second circuits, each second circuit being connected to and associated with a respective second set of pixels, each second circuit generating the second control signal for all pixels in its respective second set and sensing an amount of charge stored under said second gates in the respective second set.

3. The imaging device of claim 2, wherein said first and second gates are storage gate transistors.

4. The imaging device of claim 2, wherein a portion of said pixels further comprises a third gate for storing charge from said photosensor when activated by a third control signal.

5. The imaging device of claim 4, wherein said first, second and third gates are storage gate transistors.

6. The imaging device of claim 4, wherein said device further comprises a plurality of third circuits, each third circuit being connected to and associated with a respective third gate, each third circuit generating the third control signal for its respective third gate and sensing an amount of charge stored under said third gate.

7. The imaging device of claim 6, further comprising a line buffer memory for storing digitized values of the sensed charge from said first, second and third gates.

8. The imaging device of claim 6, wherein said sensed charge is used to determine scene information of an obtained image.

9. The imaging device of claim 4, wherein said third gates are organized as a diagonal pattern across said array.

10. The imaging device of claim 1, wherein said sensed charge is used to determine scene information of an obtained image.

11. The imaging device of claim 10, wherein said scene information is used to detect motion of objects in an obtained image.

12. The imaging device of claim 10, wherein said scene information is used in an automatic balancing operation for the device.

13. The imaging device of claim 10, wherein said scene information is used in a white balancing operation for the device.

14. The imaging device of claim 1, wherein said first gate is a transfer gate and said first control signal is a transfer gate control signal.

15. The imaging device of claim 1, wherein said plurality of pixels are organized into an array of rows and columns, and each first set of pixels corresponds to a respective row of pixels.

16. The imaging device of claim 15, wherein each second set of pixels corresponds to a respective column of pixels.

17. The imaging device of claim 1 further comprising column sample and hold circuitry connected to columns of said pixels, said column sample and hold circuitry digitizing the sensed amount of charge from the plurality of first circuits, wherein said sensed amount of charge from the plurality of first circuits are routed through a pixel array comprising said pixels.

18. A system comprising:

a processor; and

an imaging device communicating with said processor, said device comprising;

a plurality of pixels organized as an array of rows and columns, each pixel in said array comprising a photosensor and at least a first gate for storing charge from said photosensor when activated by a first control signal, and

a plurality of first circuits, each first circuit being connected to and associated with a respective first set of pixels, each first circuit generating the first control signal on a first control line for all pixels in its respective first set and sensing via the first control line an amount of charge stored under said first gates in the respective first set.

19. The system of claim 18, wherein each pixel further comprises a second gate for storing charge from said photosensor when activated by a second control signal, and

said device further comprises a plurality of second circuits, each second circuit being connected to and associated with a respective second set of pixels, each second circuit generating the second control signal for all pixels in its respective second set and sensing an amount of charge stored under said second gates in the respective second set.

20. The system of claim 19, wherein said first and second gates are storage gate transistors.

21. The system of claim 19, wherein a portion of said pixels further comprises a third gate for storing charge from said photosensor when activated by a third control signal.

22. The system of claim 21, wherein said first, second and third gates are storage gate transistors.

23. The system of claim 21, wherein said device further comprises a plurality of third circuits, each third circuit being connected to and associated with a respective third gate, each third circuit generating the third control signal for its respective third gate and sensing an amount of charge stored under said third gate.

24. The system of claim 23, further comprising a line buffer memory for storing digitized values of the sensed charge from said first, second and third gates.

25. The system of claim 23, wherein said sensed charge is used to determine scene information of an obtained image.

26. The system of claim 21, wherein said third gates are organized as a diagonal pattern across said array.

27. The system of claim 18, wherein said sensed charge is used to determine scene information of an obtained image.

28. The system of claim 27, wherein said scene information is used to detect motion of objects in an obtained image.

29. The system of claim 27, wherein said scene information is used in an automatic balancing operation for the device.

30. The system of claim 27, wherein said scene information is used in a white balancing operation for the device.

31. The system of claim 18, wherein said plurality of pixels are organized into an array of rows and columns, and each first set of pixels corresponds to a respective row of pixels.

32. The system of claim 31, wherein each second set of pixels corresponds to a respective column of pixels.

33. A method of operating an imaging device, the imaging device comprising a plurality of pixels, each comprising a photosensor and at least a first storage gate, said method comprising the acts of:

for each pixel, storing charge from the photosensor to the first gate by placing a control signal on a control line;

for each pixel, sensing via the first control line the charge stored on the first gate; and

using the sensed charges to obtain a first signature of a first image scene obtained by the imaging device,

wherein the first signature is processed in at least one operation consisting of motion detection, automatic balancing and white balancing.

34. The method of claim 33, wherein each pixel comprises a second gate and said method further comprises the acts of:

for each pixel, storing charge from the photosensor to the second gate;

for each pixel, sensing the charge stored on the second gate; and

using the sensed charge to obtain a second signature of the first image scene obtained by the imaging device.

35. The method of claim 34, wherein said acts of storing charge from the photosensor to the first gate through the act of using the sensed charge to obtain a second signature of the image scene obtained by the imaging device are repeated for a second image scene obtained by the imaging device.

36. The method of claim 35 further comprising the act of using the first and second signatures of the first and second scenes to determine if there has been movement between images within the scenes.

37. The method of claim 35 further comprising the act of using the first and second signatures of the first and second scenes to perform motion estimation.

38. The method of claim 35 further comprising the act of using one of the first and second signatures of the first and second scenes for an automatic balancing operation.

39. The method of claim 35 further comprising the act of using one of the first and second signatures of the first and second scenes for a white balancing operation.

40. The method of claim 34, wherein a portion of the pixels comprises a third gate and said method further comprises the acts of:

for each pixel comprising the third gate, storing charge from the photosensor to the third gate;

for each pixel comprising the third gate, sensing the charge stored on the third gate; and

using the sensed charge to obtain a third signature of the first image scene obtained by the imaging device.

41. The method of claim 40, wherein said acts of storing charge from the photosensor to the first gate through the act of using the sensed charge to obtain a third signature of the image scene obtained by the imaging device are repeated for a second image scene obtained by the imaging device.

42. The method of claim 41 further comprising the act of using the first, second and third signatures of the first and second scenes to determine if there has been movement between images within the scenes.

43. The method of claim 41 further comprising the act of using the first, second and third signatures of the first and second scenes to perform motion estimation.

44. The method of claim 41 further comprising the act of using one of the first, second and third signatures of the first and second scenes for an automatic balancing operation.

45. The method of claim 41 further comprising the act of using one of the first, second and third signatures of the first and second scenes for a white balancing operation.