Patent ID: 7733400

Claim:
A CMOS active pixel comprising: a photodiode which generates signal charges according to received photons; a capacitance node which receives the signal charges generated from the photodiode; a reset transistor which resets the capacitance node in response to a reset control signal, wherein the reset control signal is continuously activated for a first predetermined time period during which the reset transistor is activated to form an initialization state on which electronic potential energy in area of the photodiode becomes a ground state; a floating diffusion node which gates a driving transistor, the driving transistor being controlled by a voltage level of the floating diffusion node; a select transistor which transmits a voltage transmitted by the driving transistor to a corresponding data line in response to a row selection signal; and a capacitor transistor which has first and second source/drain ports connected to the capacitance node and the floating diffusion node, respectively, and is gated in response to a capacitor control signal, the capacitor transistor being activated in response to the capacitor control signal to form a capacitance; wherein the capacitor control signal becomes in an inactivation state during the first predetermined time period so that the capacitor transistor is activated to form the capacitance during a second predetermined time period between a start time of the first predetermined time period and a start time of the inactivation state of the capacitor control signal; and wherein electronic potentials in regions of the capacitor transistor and the floating diffusion node are higher than electronic potential in region of the photodiode in the initialization state, and a depletion region in the region of the photodiode does not increase.