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US 2018/0124344 A1Published application
Image sensor
AssigneePixart Imaging Inc.
InventorEn-Feng HSU
Life of this patent
Estimating the term…
Abstract
There is provided an operating method of an image sensor including: storing a first charge from an optoelectronic circuit to a pixel buffer circuit within a first exposure period; storing a second charge from the optoelectronic circuit to the pixel buffer circuit within a second exposure period; transferring the first charge from the pixel buffer circuit to a first storage circuit outside of pixel circuits; transferring the second charge from the pixel buffer circuit to a second storage circuit outside of pixel circuits; and comparing the first charge with the second charge to output an analog image signal.
Claims18
An image sensor, comprising:
- a plurality of pixel circuits arranged in a matrix, each of the pixel circuits comprising:
- an optoelectronic conversion circuit configured to generate a photocurrent;
- a pixel buffer circuit configured to receive the photocurrent within a first exposure time to store a first charge and store the first charge for a selectable storage interval, and receive the photocurrent within a second exposure time to store a second charge, wherein the selectable storage interval is between the first exposure time and the second exposure time;
- and
- a plurality of output circuits, each of the output circuits coupled to one pixel circuit column via a readout line and comprising:
- a first storage circuit configured to store a first output voltage formed by reading the first charge in the pixel buffer circuit within a readout interval;
- a second storage circuit configured to store a second output voltage formed by reading the second charge in the pixel buffer circuit within the readout interval;
- and
- a differential unit configured to compare, within the readout interval, the first output voltage with the second output voltage to output an analog image signal.
6 more elements
An image sensor, comprising:
- a plurality of pixel circuits arranged in a matrix, each of the pixel circuits comprising:
- an optoelectronic conversion circuit configured to generate a photocurrent;
- a floating diffusion region configured to sequentially store a first reset charge and a first accumulation charge of accumulating a first charge and the first reset charge within a second exposure time, and sequentially store a second reset charge and a second accumulation charge of accumulating a second charge and the second reset charge within a readout interval;
- a storage node configured to receive the photocurrent within a first exposure time to store the first charge for a selectable storage interval, sequentially transfer the first charge to the floating diffusion region to generate the first accumulation charge and receive the photocurrent to store the second charge within the second exposure time, and transfer the second charge to the floating diffusion region to generate the second accumulation charge within the readout interval, wherein the selectable storage interval is between the first exposure time and the second exposure time;
- and
- a plurality of output circuits, each of the output circuits coupled to one pixel circuit column via a readout line and configured to
- sequentially store the first reset charge and the first accumulation charge formed by reading the floating diffusion region within the second exposure time,
- sequentially store the second reset charge and the second accumulation charge formed by reading the floating diffusion region within the readout interval, and
- calculate, with the readout interval, a first differential signal between the first reset charge and the first accumulation charge, a second differential signal between the second reset charge and the second accumulation charge, and an analog image signal between the first differential signal and the second differential signal.
6 more elements
Dependencies are inferred from the claim text.