A plurality of pixels PX include effective pixels and optical black pixels. Signal lines VL are provided corresponding to each column of the pixels PX and supplied with output signals of the pixels PX of the corresponding column. Clip transistors CL are provided corresponding to the respective signal lines VL and limit a potential of the corresponding vertical signal lines VL based on a gate potential. At least in a predetermined operating mode, a potential Vclip_dark is supplied to a gate of one of the clip transistors CL corresponding to at least one pixel column formed of the optical black pixels when reading a noise level from the pixels PX corresponding to the clip transistors CL and when reading a data level from the pixels PX corresponding to the clip transistors CL.