Imaging systems with image pixels having adjustable responsivity

摘要

An imaging system may include an image sensor having an array of image pixels. Some image pixels in the array may be provided with responsivity adjustment structures. For example, broadband pixels in a pixel array may include responsivity adjustment circuitry. The responsivity adjustment circuitry may be configured to narrow the spectral response or to reduce the conversion gain of the broadband pixels in high light conditions. For example, a deep photodiode may divert charge away from a signal photodiode during an integration period. The deep photodiode may divert charge to a power supply or the charge may be transferred to a storage node and used in image processing, if desired. The responsivity adjustment circuitry may include channel-dependent conversion circuitry that is formed in pixels corresponding to a first color channel, while the conversion gains of pixels corresponding to a second color channel may remain fixed.

主权项

1. An image sensor, comprising:
a substrate; an image pixel array formed in the substrate, wherein the image pixel array includes first and second groups of image pixels and wherein each image pixel in the first and second groups of image pixels comprises a signal photodiode; and spectral response adjustment circuitry in each image pixel in the first group of image pixels, wherein the spectral response adjustment circuitry comprises a responsivity adjustment photodiode that is configured to divert charge from the signal photodiode, wherein the first group of image pixels comprises broadband image pixels having broadband color filter elements, wherein the second group of image pixels comprises red and blue image pixels having red and blue color filter elements, and wherein the responsivity adjustment photodiode is surrounded on three sides by the signal photodiode in the substrate.