High dynamic range imaging with multi-storage pixels

摘要

High dynamic range imaging techniques with multi-storage pixels are provided. Multiple images may be captured during a single exposure using an image sensor with multi-storage pixels. During a single exposure, charge from photodiodes may be transferred alternately to multiple storage nodes of the multi-storage pixels. During readout of a multi-storage pixel, charge may be transferred from each of multiple storage nodes one at a time to a floating diffusion node. Each subsequent transfer of charge may be summed with the charge already stored in the floating diffusion node. A pixel signal may be read out from the multi-storage pixel after each charge transfer. Images formed from the pixel signals may be combined to produce a high dynamic range image.

主权项

1. A method for capturing images with an image sensor having multi-storage pixels, wherein each multi-storage pixel has a photodiode, at least first and second storage nodes, and a floating diffusion node, for each multi-storage pixel the method comprising:
transferring from the photodiode at least first and second pluralities of charge portions to the at least first and second storage nodes, respectively; summing the first plurality of charge portions to produce a first stored charge at the first storage node; summing the second plurality of charge portions to produce a second stored charge at the second storage node; transferring the first stored charge from the first storage node to a floating diffusion node; reading out the first stored charge from the floating diffusion node as a first pixel signal having a first exposure time, without resetting the floating diffusion node; transferring the second stored charge from the second storage node to the floating diffusion node; reading out a sum of the first and second stored charges from the floating diffusion node as a second pixel signal having a second exposure time, wherein the at least first and second storage nodes comprise first, second, third, and fourth storage nodes and wherein the at least first and second pluralities of charge portions comprise first, second, third, and fourth pluralities of charge portions, without resetting the floating diffusion node; transferring the third stored charge from the third storage node to the floating diffusion node; reading out a sum of the first, second and third stored charges from the floating diffusion node as a third pixel signal having a third exposure time, without resetting the floating diffusion node; transferring the fourth stored charge from the fourth storage node to the floating diffusion node; and reading out a sum of the first, second, third, and fourth stored charges from the floating diffusion node as a fourth pixel signal having a fourth exposure time.