Active pixel sensor with reduced fixed pattern noise
First Claim
Patent Images
1. A pixel array, comprising:
- a plurality of pixels, each pixel including;
a photoactive region and an active region separated by a first transfer gate, anti-blooming and storage regions selectively connectable to the active region and separated from the active region by second and third transfer gates, respectively, and a reset gate selectively connectable to the storage region; and
a controller operable to control the transfer and reset gates of the plurality of pixels, wherein the controller is operable to;
set the active region of a pixel to a predetermined charge level;
cause charge accumulated in the photoactive region of the pixel during a non-charge integration period to be transferred to the active region of the pixel;
cause charge from the active region to be transferred to the anti-blooming region of the pixel;
reset the active region to the predetermined charge level;
cause charge accumulated in the photoactive region during a charge integration period to be transferred to the active region of the pixel; and
cause charge from the active region to be transferred to the storage region of the pixel.
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Abstract
An image sensor includes pixels each of which is designed to transfer charge, accumulated in a photoactive region of the pixel during a first period, through a second active region of the pixel to a power supply node, and to transfer charge, accumulated in the photoactive region during a second period, through the second active region to a sense node in the pixel. Passing charge through the second active region prior to transferring it either to the power supply node or the sense node can help reduce fixed pattern noise. The image sensor can be operated in snap-shot mode.
23 Citations
4 Claims
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1. A pixel array, comprising:
a plurality of pixels, each pixel including; a photoactive region and an active region separated by a first transfer gate, anti-blooming and storage regions selectively connectable to the active region and separated from the active region by second and third transfer gates, respectively, and a reset gate selectively connectable to the storage region; and a controller operable to control the transfer and reset gates of the plurality of pixels, wherein the controller is operable to; set the active region of a pixel to a predetermined charge level; cause charge accumulated in the photoactive region of the pixel during a non-charge integration period to be transferred to the active region of the pixel; cause charge from the active region to be transferred to the anti-blooming region of the pixel; reset the active region to the predetermined charge level; cause charge accumulated in the photoactive region during a charge integration period to be transferred to the active region of the pixel; and cause charge from the active region to be transferred to the storage region of the pixel. - View Dependent Claims (2, 3, 4)
Specification