Pixel read circuitry
First Claim
1. A method of reading voltages from an image sensor having an array of pixels, each pixel comprising at least one photodiode connectable to a storage node, the method comprising:
- controlling each pixel in a row of pixels to store and output a first voltage value at a first instance, a second voltage value at a second instance, and a third voltage value at a third instance, the first, second and third voltage values being representative of charge accumulated by said photodiodes during an integration phase;
comparing the first voltage value from each pixel with a reference threshold;
sampling for each pixel, based on said comparison, only one of said second and third voltage values; and
generating an output pixel value based on only the sampled one of said second and third voltage values.
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Accused Products
Abstract
A method of reading voltages from an image sensor having an array of pixels, each pixel Having at least one photodiode connectable to a storage node, the method including: controlling each pixel in a row of pixels to store and output a first voltage value at a first instance, a second voltage value at a second instance, and a third voltage value at a third instance, the first, second and third voltage values being representative of charge accumulated by the photodiodes during an integration phase; comparing the first voltage value from each pixel with a reference threshold; sampling for each pixel, based on the comparison, one of the second and third voltage values, and generating an output pixel value based on the sampled one of the second and third voltage values.
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Citations
27 Claims
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1. A method of reading voltages from an image sensor having an array of pixels, each pixel comprising at least one photodiode connectable to a storage node, the method comprising:
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controlling each pixel in a row of pixels to store and output a first voltage value at a first instance, a second voltage value at a second instance, and a third voltage value at a third instance, the first, second and third voltage values being representative of charge accumulated by said photodiodes during an integration phase; comparing the first voltage value from each pixel with a reference threshold; sampling for each pixel, based on said comparison, only one of said second and third voltage values; and generating an output pixel value based on only the sampled one of said second and third voltage values. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An image sensor comprising:
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an array of pixels, each pixel comprising at least one photodiode and a first transistor associated with said photodiode controllable to connect said photodiode to a storage node in said pixel to store a voltage value representative of a voltage of said photodiode; row control circuitry arranged to control the first transistors in a row of said pixels to each store first, second and third voltage values representative of voltages of the photodiodes at respective first, second and third instances during an integration phase of the photodiodes, and to output said first, second and third voltage values; and output circuitry arranged to sample said first voltage value and to compare said first voltage values for each pixel with a reference threshold, and to sample for each pixel, based on said comparison, only one of said second and third voltage values for use in generating an output pixel value. - View Dependent Claims (8, 9, 10, 11)
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12. A method of reading voltages from an image sensor having an array of pixels, each pixel comprising at least one photodiode connectable to a storage node, the method comprising:
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outputting, for each pixel in a row of pixels, a first voltage value at a first time during an integration phase; comparing the first voltage value for each pixel with a first reference value; outputting, for each pixel in the row of pixels, a second voltage value at a second time during the integration phase and a third voltage value at a third time during the integration phase, the first, second and third voltage values representing charge accumulated by the photodiode during the integration phase; selecting only one of the second and third voltage values based on a result of the comparison; and generating, for each pixel in the row of pixels, an output pixel value, including digitizing the selected only one of the second and third voltage values. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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21. An image sensor comprising:
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an array of pixels, each pixel comprising at least one photodiode and a first transistor; row control circuitry configured to control the first transistors in a row of pixels to output a first voltage value at a first time, a second voltage value at a second time and a third voltage value at a third time, the first, second and third voltage values being representative of charge accumulated by the photodiode during an integration phase; and output circuitry configured to compare the first voltage value for each pixel with a first reference value and to select only one of the second and third voltage values based on a result of the comparison, wherein only the selected one of the second and third voltage values is used to generate an output pixel value. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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Specification