Two-Stage Imaging Pixel Circuit for kTC Noise and Offset Reduction

The pixel array is divided into multiple blocks, and reset operations are performed sequentially for each block rather than simultaneously for all pixels. This segmentation approach maintains the global shutter capability for eliminating focal plane distortion while reducing kTC noise by spreading out the reset events across different time periods.

The reset operation is performed periodically block by block instead of once for all pixels. By resetting different blocks at different periodic intervals, the patent reduces the simultaneous generation of kTC noise while still achieving global shutter effect for each block during its exposure period.

By dividing the pixel array into blocks and processing them sequentially, the patent enables offset cancellation to be performed for each block individually. This segmentation makes offset cancellation more manageable compared to handling all pixels simultaneously, while still maintaining synchronized exposure timing within each block.

The patent performs preliminary reset and offset cancellation operations for each block before moving to the next block. This preliminary action approach allows offset cancellation to be completed in advance for each segment, making the overall process more efficient and easier to control.

By segmenting the pixel array into blocks and performing reset and AD conversion operations on a per-block basis, the patent reduces the total number of reset operations needed compared to resetting all pixels multiple times. This segmentation approach achieves adequate offset cancellation while minimizing temporal loss.

The patent performs offset cancellation for each block individually rather than requiring multiple complete reset cycles for the entire array. This partial action approach achieves sufficient offset cancellation for each block without the excessive time cost of multiple full-array reset operations.