A solid state image sensor capable of preventing image degradation, such as shading and ringing, from occurring in an image portion along the left edge of a screen. The solid state image sensor includes, in addition to a horizontal drive circuit that generates a horizontal drive pulse for driving a horizontal register, a pseudo-horizontal drive circuit that generates a pseudo-horizontal drive pulse successive to the horizontal drive pulse during a horizontal blanking interval. The horizontal drive circuit and pseudo-horizontal drive circuit are connected to a horizontal driver power supply unit, which generates, during the horizontal blanking interval, a current that is equal to a current generated by the horizontal driver power supply unit during an effective interval. This arrangement can prevent any power supply ripples from occurring immediately after the beginning of the effective interval.