Pixel read circuitry
AssigneeSTMicroelectronics S.r.l.
InventorsBenoit Deschamps, Frederic Barbier
Life of this patent
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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
Claims11
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, one of said second and third voltage values;
- and
- generating an output pixel value based on the sampled one of said second and third voltage values.
An image sensor comprising:
- 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 times 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, one of said second and third voltage values for use in generating an output pixel value.
Dependencies are inferred from the claim text.