Patent ID: 7652697
Filing Date: 2010-01-26
Classification: H01L,H04N

Abstract:
1. A method of detecting a saturation level of an image sensor including a photodiode using a black pixel circuit that includes a floating diffusion node connected to or disconnected from the photodiode, a reset node connected to or disconnected from the floating diffusion node, and a detection controller transferring a power voltage or a reference voltage to the reset node and outputs a voltage signal corresponding to the voltage of the floating diffusion node, comprising the steps of: transferring the reference voltage to the photodiode via the reset node and the floating diffusion node to saturate the photodiode; transferring the power voltage to the floating diffusion node via the reset node to reset the floating diffusion node; outputting a voltage signal having a reset level corresponding to a voltage of the reset floating diffusion node; connecting the saturated photodiode to the reset floating diffusion node to saturate the floating diffusion node; and outputting a voltage signal having a saturation level, corresponding to a voltage of the saturated floating diffusion node.