Wide dynamic range image sensor
AssigneeESS Technology, Inc.
InventorRichard A. Mann
Life of this patent
Estimating the term…
Abstract
An exemplary image sensor comprises a photodetector proximate to a pixel site, and a light meter proximate to the pixel site configured to approximate an initial charge acquired by the photodetector at the end of a first integration period of a frame exposure period. A reset circuit resets the photodetector if the approximated initial charge acquired by the photodetector exceeds a threshold. A readout circuit detects a final charge acquired by the photodetector at the end of a second integration period of the frame exposure period. If the photodetector was reset, the readout circuit adjusts the final exposure to account for exposure prior to the photodetector having been reset.
Claims18
An image sensor circuit comprising:
- a photodetector proximate to a pixel site;
- a light meter proximate to said pixel site configured to approximate initial exposure of said photodetector;
- a reset circuit configured to reset said photodetector if said initial exposure exceeds a threshold;
- a readout circuit configured to detect a final exposure of said photodetector, said readout circuit further configured to adjust said final exposure if said photodetector was reset.
An apparatus comprising:
- a photodetector proximate to a pixel site of an image sensor;
- a light meter proximate to said pixel site;
- a controller coupled to said photodetector and to said light meter, said controller configured to cause an evaluation of an initial exposure of said photodetector, said controller further configured to cause a selective modification of said initial exposure of said photodetector, said controller further configured to cause a final exposure of the photodetector to be adjusted dependent upon said selective modification.
A method comprising:
- approximating an initial exposure of a plurality of photodetector included in an image sensor, by a single reference common to said plurality of photodetectors, at an end of a first integration period of a frame exposure period;
- resetting said plurality of photodetectors if said initial exposure exceeds a threshold;
- detecting a final exposure of said plurality of photodetectors at an end of a second integration period of said frame exposure period;
- adjusting said final exposure if said plurality of photodetectors was reset.
Dependencies are inferred from the claim text.