METHODS FOR CAPTURING AND READING OUT IMAGES FROM AN IMAGE SENSOR

• US 20110074998A1
• Filed: 09/30/2009
• Published: 03/31/2011
• 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.
• Granted Patent: US 8,279,317 B2
• Time in Patent Office: Days
• US Class Current: 348/311
• CPC Class Codes: H04N 25/583 with different integration times
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures
• CPC Class Codes: H04N 25/625 for the control of smear
• 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 capturing 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 a first portion of pixels to respective charge storage elements in the VCCDs at a first time, wherein the charge packets from the first portion of pixels have a first integration period;

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

ending light integration for all of the pixels;

reading out the charge packets from the VCCDs;

resetting the photosensitive areas;

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

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

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

ending light integration for all of the pixels; 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 prior to beginning light integration for all of the pixels and transferring charge packets from a first portion of pixels to respective charge storage elements in the VCCDs at a first time.

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

4. The method of claim 3, wherein ending light integration for all of the pixels comprises closing the mechanical shutter.

5. The method of claim 1, transferring charge packets from a first portion of pixels to respective charge storage elements in the VCCDs at a first time comprises transferring charge packets from odd numbered lines of pixels to respective charge storage elements in the VCCDs at a first time, wherein the charge packets from the odd numbered lines of pixels have a first integration period.

6. The method of claim 5, transferring charge packets from a second portion of pixels to respective charge storage elements in the VCCDs at a first time comprises transferring charge packets from even numbered lines of pixels to respective charge storage elements in the VCCDs at a first time, wherein the charge packets from the even numbered lines of pixels have a second integration period.

7. The method of claim 1, wherein the first and second portions of pixels comprise single lines of pixels.

8. The method of claim 1, wherein the first and second portions of pixels comprise multiple lines of pixels.

9. The method of claim 8, wherein the multiple lines of pixels comprise multiple adjacent lines of pixels, and wherein the first and second portions of pixels alternate with respect to each other.