High dynamic range CMOS image sensor having anti-blooming properties and associated methods
First Claim
1. A method of providing blooming protection to a CMOS imager having a pixel array of a plurality of pixels arranged in rows and columns, where the CMOS imager is operable to capture high dynamic range images using a rolling shutter, comprising:
- selecting a readout row of pixels;
starting a first integration time of the pixels in the readout row;
reading out charge accumulated by the pixels in the readout row to obtain a first readout;
applying a reset to the readout row for a reset time sufficient to allow readout and reset to occur in at least three subsequent rows, wherein the reset is applied for the reset time sufficient such that the at least three subsequent rows and the readout row are simultaneously reset;
removing the reset and starting a second integration time of the pixels in the readout row, wherein the second integration time is shorter than the first integration time, and wherein the at least one subsequent row is a sufficient number of rows to have a combined reset to at least substantially preclude blooming effects from the pixel array in the readout row during the second integration time; and
reading out charge accumulated by the pixels in the readout row to obtain a second readout.
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Accused Products
Abstract
A method of providing blooming protection to a CMOS imager having a pixel array of a plurality of pixels arranged in rows and columns, where the CMOS imager is operable to capture high dynamic range images using a rolling shutter, is provided. Such a method can include reading out charge accumulated by the pixels in a readout row of a first integration time, applying a reset to the readout row for a reset time sufficient to allow readout and reset to occur in at least one subsequent row, and starting a second integration time of the pixels in the readout row, wherein the second integration time is shorter than the first integration time, and wherein the at least one subsequent row is a sufficient number of rows to have a combined reset to preclude blooming effects from the pixel array during the second integration time.
527 Citations
23 Claims
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1. A method of providing blooming protection to a CMOS imager having a pixel array of a plurality of pixels arranged in rows and columns, where the CMOS imager is operable to capture high dynamic range images using a rolling shutter, comprising:
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selecting a readout row of pixels; starting a first integration time of the pixels in the readout row; reading out charge accumulated by the pixels in the readout row to obtain a first readout; applying a reset to the readout row for a reset time sufficient to allow readout and reset to occur in at least three subsequent rows, wherein the reset is applied for the reset time sufficient such that the at least three subsequent rows and the readout row are simultaneously reset; removing the reset and starting a second integration time of the pixels in the readout row, wherein the second integration time is shorter than the first integration time, and wherein the at least one subsequent row is a sufficient number of rows to have a combined reset to at least substantially preclude blooming effects from the pixel array in the readout row during the second integration time; and reading out charge accumulated by the pixels in the readout row to obtain a second readout. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of using a rolling shutter to provide blooming protection in a CMOS imager in high dynamic range mode and having a pixel array of a plurality of pixels arranged in rows and columns, comprising:
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capturing a first image in the pixel array having a first integration time; reading the first image out of the pixel array sequentially by rows using at least one readout row of the first image; hard resetting a plurality of rows in proximity to the at least one readout row of the first image; capturing a second image in the pixel array having a second integration time, the second integration time being shorter than the first integration time, wherein the second image is protected from blooming caused by the first image by the hard resetting of the plurality of rows in proximity to the readout row of the first image; reading the second image out of the pixel array sequentially by rows using at least one readout row of the second image; hard resetting a plurality of rows in proximity to the at least one readout row of the second image; capturing a third image in the pixel array having a third integration time, the third integration time being shorter than the second integration time, wherein the third image is protected from blooming caused by the first or the second image by the hard resetting of the plurality of rows in proximity to the readout row of the second image; and reading the third image out of the pixel array sequentially by rows using at least one readout row of the third image. - View Dependent Claims (17, 18)
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19. A method of providing blooming protection to a CMOS imager having a pixel array of a plurality of pixels arranged in rows and columns, where the CMOS imager is operable to capture high dynamic range images using a rolling shutter, comprising:
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selecting a readout row of pixels; starting a first integration time of the pixels in the readout row; reading out charge accumulated by the pixels in the readout row to obtain a first readout; applying a reset to the readout row for a reset time sufficient to allow readout and reset to occur in at least one subsequent row; removing the reset and starting a second integration time of the pixels in the readout row, wherein the second integration time is shorter than the first integration time, and wherein the at least one subsequent row is a sufficient number of rows to have a combined reset to at least substantially preclude blooming effects from the pixel array in the readout row during the second integration time; and reading out charge accumulated by the pixels in the readout row to obtain a second readout; applying the reset to the readout row following the second readout for a reset time sufficient to allow readout and reset to occur in at least one subsequent row; removing the reset and starting a third integration time of the pixels in the readout row, wherein the third integration time is shorter than the second integration time, and wherein the at least one subsequent row is a sufficient number of rows to have a combined reset to at least substantially preclude blooming effects from the pixel array in the readout row during the third integration time; and reading out charge accumulated by the pixels in the readout row to obtain a third readout. - View Dependent Claims (20, 23)
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21. A method of providing blooming protection to a CMOS imager having a pixel array of a plurality of pixels arranged in rows and columns, where the CMOS imager is operable to capture high dynamic range images using a rolling shutter, comprising:
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selecting a readout row of pixels; starting a first integration time of the pixels in the readout row; reading out charge accumulated by the pixels in the readout row to obtain a first readout; applying a reset to the readout row for a reset time sufficient to allow readout and reset to occur in at least one subsequent row, wherein the reset is applied at a variable voltage level throughout the reset time duration; removing the reset and starting a second integration time of the pixels in the readout row, wherein the second integration time is shorter than the first integration time, and wherein the at least one subsequent row is a sufficient number of rows to have a combined reset to at least substantially preclude blooming effects from the pixel array in the readout row during the second integration time; and reading out charge accumulated by the pixels in the readout row to obtain a second readout. - View Dependent Claims (22)
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Specification