An image sensor according to some example embodiments includes a pixel array unit including a plurality of transmission signal lines and a plurality of output signal lines, and a plurality of pixels connected to the plurality of transmission signal lines and the plurality of output signal lines. Each of the plurality of pixels includes a plurality of photoelectric conversion elements, which are configured to detect and photoelectrically convert incident light. The plurality of pixels include at least one autofocusing pixel and at least one normal pixel.