Photoelectric conversion apparatus and image pickup system
AssigneeCanon Kabushiki Kaisha
InventorsSeiji Hashimoto, Takeru Suzuki, Yasushi Matsuno, Takashi Muto
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Abstract
A photoelectric conversion apparatus includes a plurality of pixels provided in a plurality of columns, a plurality of analog-to-digital conversion units each provided for a corresponding one of the plurality of columns, and a correction unit. Each of the plurality of analog-to-digital conversion units is configured to convert a signal of a corresponding one of the plurality of pixels into a digital signal at a resolution corresponding to a magnitude of the signal. The correction unit is configured to correct a difference in the resolution.
Claims13
A photoelectric conversion apparatus comprising:
- a plurality of pixels provided in a plurality of columns;
- a reference signal generating unit configured to generate a first reference signal and a second reference signal, the first reference signal having a first changing rate with respect to time, and the second reference signal having a second changing rate with respect to time, wherein the first changing rate is smaller than the second changing rate;
- a plurality of analog-to-digital conversion units each provided for a corresponding one of the plurality of columns, each of the plurality of analog-to-digital conversion units being configured to convert a signal output from a corresponding pixel of the plurality of pixels into a digital signal by comparing the signal and one of the first reference signal and the second reference signal;
- and
- a correction unit configured to correct the digital signal based on an error in comparison to an ideal ratio of the first changing rate and the second changing rate.
A photoelectric conversion apparatus comprising:
- a plurality of pixels provided in a plurality of columns;
- a plurality of analog-to-digital conversion units each provided for a corresponding one of the plurality of columns, each of the plurality of analog-to-digital conversion units being configured to convert a signal output from a corresponding pixel of the plurality of pixels into a digital signal at a resolution corresponding to a magnitude of the signal;
- and
- a correction unit configured to correct the digital signals generated by different resolutions between the plurality of analog-to-digital conversion units based on an error in comparison to an ideal ratio of the different resolutions,
- wherein each of the plurality of analog-to-digital conversion units generates the digital signal in accordance with a reference signal that changes with respect to time,
- wherein the resolution is determined in accordance with a rate of change of the reference signal with respect to time,
- wherein the signal output from the pixel includes a signal obtained through photoelectric conversion,
- wherein each of the plurality of analog-to-digital conversion units determines a slope of the reference signal used for the signal obtained through photoelectric conversion, in accordance with a result of comparing a level of the signal obtained through photoelectric conversion with a comparison level,
- wherein the slope of the reference signal is selected from among two or more values, and
- wherein a period over which the reference signal changes is longer when a larger slope is selected from among the two or more values.
Dependencies are inferred from the claim text.