Methods for capturing and reading out images from an image sensor

• US 8,314,873 B2
• Filed: 09/30/2009
• Issued: 11/20/2012
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: TRUESENSE Imaging, Inc. (ON Semiconductor Corporation)
• Inventors: Border, John N., Compton, John T., Nichols, David N.
• Primary Examiner(s): SELBY, GEVELL V
• Application Number:
  US12/570,014
• Publication Number:
  US 20110075008A1
• Time in Patent Office: 1,147 Days
• Field of Search: 348/275, 348/311, 348/317, 348/362
• US Class Current: 348/311
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 25/46 by combining or binning pixels
• CPC Class Codes: H04N 25/53 Control of the integration time
• CPC Class Codes: H04N 25/575 with a response composed of multiple slopes
• CPC Class Codes: H04N 25/581 acquired simultaneously
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures
• CPC Class Codes: H04N 25/713 Transfer or readout registers; Split readout registers or multiple readout registers
• CPC Class Codes: H04N 25/73 using interline transfer [IT]

Abstract

Multiple images are captured where the exposure times for some of the images overlap and the images are spatially overlapped. Charge packets are transferred from one or more portions of pixels after particular integration periods, thereby enabling the portion or portions of pixels to begin another integration period while one or more other portions of pixels continue to integrate charge. Charge packets may be binned during readout of the images from the image sensor. Comparison of two or more images having different lengths of overlapping or non-overlapping exposure periods provides motion information. The multiple images can then be aligned to compensate for motion between the images and assembled into a combined image with an improved signal to noise ratio and reduced motion blur.

Claims

1. A method for producing multiple images with an image sensor that includes a plurality of pixels each including a photosensitive area, a plurality of vertical charge coupled devices (VCCDs) each comprising a plurality of charge storage elements and positioned adjacent to respective columns of pixels, and transfer mechanisms for transferring charge packets from the photosensitive areas to respective charge storage elements, the method comprising:

beginning light integration for all of the pixels, wherein the photosensitive areas accumulate charge packets;

transferring charge packets from all of the pixels to respective charge storage elements in the VCCDs at a first time, wherein the charge packets from the pixels have a first integration period;

binning charge packets in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD, thereby combining charge packets in the portion of charge packets with other charge packets in the VCCDs;

ending light integration for all of the pixels;

transferring charge packets from all of the pixels to respective charge storage elements in the VCCDs at a second time, wherein the charge packets from the pixels have a second integration period, thereby binning charge packets of the same color and having at least two different integration periods in the VCCDs; and

reading out the charge packets from the VCCDs.

2. The method of claim 1, further comprising resetting the photosensitive areas in the image sensor.

3. The method of claim 1, wherein binning charge packets in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD comprises binning charge packets in the VCCDs by shifting a portion of the charge packets one charge storage element in each VCCD.

4. The method of claim 1, wherein beginning light integration for all of the pixels comprises opening a mechanical shutter.

5. The method of claim 4, wherein ending light integration for all of the pixels comprises closing the mechanical shutter.

6. The method of claim 1, wherein binning charge packets in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD comprises binning charge packets of the same color and having the same integration period in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD.

7. The method of claim 1, wherein binning charge packets in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD comprises binning charge packets of different colors and having the same integration period in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD.

8. The method of claim 1, wherein each charge storage element in the VCCDs is associated with only a single pixel.

9. The method of claim 1, wherein beginning light integration for all of the pixels comprises performing an electronic shutter operation.

10. The method of claim 9, wherein ending light integration for all of the pixels comprises performing an electronic shutter operation.

11. The method of claim 1, wherein each pixel comprises a color filter element associated therewith.

12. The method of claim 11, wherein the color filter elements are arranged in a repeating pattern comprising two different pairs of adjacent rows, the two rows of each pair comprising the same arrangement of color filter elements, and the rows of one pair comprising a different arrangement of color filter elements than the rows of the other pair.

13. The method of claim 12, wherein the pattern comprises one pair of rows alternating with the other pair of rows.

14. The method of claim 1, wherein binning charge packets in the VCCDs comprises binning charge packets of the same color.

15. The method of claim 1, wherein binning charge packets in the VCCDs comprises binning charge packets of different colors.

16. A method for producing multiple images with an image sensor that includes a plurality of pixels each including a photosensitive area, a plurality of vertical charge coupled devices (VCCDs) each comprising a plurality of charge storage elements and positioned adjacent to respective columns of pixels, and transfer mechanisms for transferring charge packets from the photosensitive areas to respective charge storage elements, the method comprising:

beginning light integration for all of the pixels, wherein the photosensitive areas accumulate charge packets;

transferring charge packets from all of the pixels to respective charge storage elements in the VCCDs at a first time, wherein the charge packets from the pixels have a first integration period;

binning charge packets in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD, thereby combining charge packets in the portion of charge packets with other charge packets in the VCCDs;

ending light integration for all of the pixels;

transferring charge packets from all of the pixels to respective charge storage elements in the VCCDs at a second time, wherein the charge packets from the pixels have a second integration period, thereby binning charge packets of different colors and having at least two different integration periods in the VCCDs; and

reading out the charge packets from the VCCDs.

17. The method of claim 16, wherein binning charge packets in the VCCDs comprises binning charge packets of the same color.

18. The method of claim 16, wherein binning charge packets in the VCCDs comprises binning charge packets of different colors.

19. The method of claim 16, further comprising resetting the photosensitive areas in the image sensor.

20. The method of claim 16, wherein binning charge packets in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD comprises binning charge packets in the VCCDs by shifting a portion of the charge packets one charge storage element in each VCCD.

21. The method of claim 16, wherein beginning light integration for all of the pixels comprises opening a mechanical shutter.

22. The method of claim 21, wherein ending light integration for all of the pixels comprises closing the mechanical shutter.

23. The method of claim 16, wherein binning charge packets in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD comprises binning charge packets of the same color and having the same integration period in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD.

24. The method of claim 16, wherein binning charge packets in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD comprises binning charge packets of different colors and having the same integration period in the VCCDs by shifting a portion of the charge packets one or more charge storage elements in each VCCD.

25. The method of claim 16, wherein each charge storage element in the VCCDs is associated with only a single pixel.

26. The method of claim 16, wherein beginning light integration for all of the pixels comprises performing an electronic shutter operation.

27. The method of claim 26, wherein ending light integration for all of the pixels comprises performing an electronic shutter operation.

28. The method of claim 16, wherein each pixel comprises a color filter element associated therewith.

29. The method of claim 28, wherein the color filter elements are arranged in a repeating pattern comprising two different pairs of adjacent rows, the two rows of each pair comprising the same arrangement of color filter elements, and the rows of one pair comprising a different arrangement of color filter elements than the rows of the other pair.

30. The method of claim 29, wherein the pattern comprises one pair of rows alternating with the other pair of rows.