Methods for capturing and reading out images from an image sensor
View Patent ↗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.
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, transfer mechanisms for transferring charge packets from the photosensitive areas to respective charge storage elements, and a horizontal charge-coupled device (HCCD) comprising a plurality of 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;
ending light integration for all of the pixels;
transferring charge packets from a first portion of pixels to respective charge storage elements in the VCCDs at a second time, wherein the charge packets from the first portion of pixels have a second integration period that is different from the first integration period;
transferring one line of charge packets from the VCCDs into respective charge storage elements in the HCCD;
shifting the charge packets one or more charge storage elements within the HCCD;
binning charge packets in the HCCD by transferring another line of charge packets from the VCCDs into respective charge storage elements in the HCCD; and
reading out the charge packets from the HCCD.
2. The method of claim 1 , further comprising resetting the photosensitive areas in the image sensor.
3. The method of claim 1 , 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 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.
7. The method of claim 6 , wherein binning charge packets in the HCCD by transferring another line of charge packets from the VCCDs into respective charge storage elements in the HCCD comprises binning charge packets of different colors and having at least two different integration periods in the HCCD by transferring another line of charge packets from the VCCDs into respective charge storage elements in the HCCD.
8. The method of claim 1 , wherein the first portion of pixels comprises single lines of pixels.
9. The method of claim 1 , wherein the first portion of pixels comprises multiple lines of pixels.
10. The method of claim 9 , wherein the multiple lines of pixels comprise multiple adjacent lines of pixels.