An image sensor operated in a pseudo pinch-off condition capable of reducing a reset voltage of a photodiode and reducing a dark current and fixed pattern noise generated due to discordance of characteristics between pixels is presented. The image sensor has a photosensitive pixel, a driving circuit and an intermediary circuit. The photosensitive pixel can have a photodiode generating a photoelectrons, a transfer transistor transferring the photoelectrons to a diffusion node, and a reset transistor resetting the diffusion node. The driving circuit generates a driving switching signal with respect to the transfer and resist transistors. The intermediary circuit changes characteristics of the signal to drive the photosensitive pixel in a pseudo pinch-off mode.