Solid-state imaging device

Abstract

According to one embodiment, the pixel driving circuit causes the amplifying transistor to form a source follower circuit without applying a bias voltage to the vertical signal line and connects the FD to the power source. Thereafter, the pixel driving circuit separates the current source from the vertical signal line to cancel the source follower circuit, applies a bias voltage to the vertical signal line so that the voltage of the FD is raised when the brightness of the subject is higher than the reference value, and the voltage of the FD is lowered when the brightness of the subject is lower than the reference value, and turns on the read transistor. The pixel driving circuit turns off the read transistor, and then connects the current source to the vertical signal line, and causes the amplifying transistor to form the source follower circuit.

Description

[0001] This application is based on and claims priority from Japanese Patent Application No. 2010-068766 filed on March 24, 2010, the entire contents of which are hereby incorporated by reference. technical field [0002] This embodiment relates to a general solid-state imaging device. Background technique [0003] A unit pixel constituting a pixel array of a CMOS image sensor that is a representative example of a solid-state imaging device includes: a photodiode that performs photoelectric conversion; and a readout transistor that functions as a capacitive element by converting and storing signal charges in the photodiode. The floating diffusion layer (floating diffusion, hereinafter referred to as "FD") is read; the reset transistor is used to set the voltage of FD to the power supply voltage; the amplifying transistor is used to form a source tracker circuit using a current source connected to a vertical signal line At this time, the voltage of the FD is converted into a ...

AI Technical Summary

Problems solved by technology

With the reduction of the pixel size, there is a problem that the charge storage capacity of the FD (dynamic range: dynamic range ) is insufficient, and all the signal charges after conversion and storage of the photodiode cannot be read out to the FD.

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