The second control mode will be explained next. The image sensor 3 set in the second control mode by the control unit 4 reads out a signal by combining (synthesizing) signals from a plurality of pixels 10. For instance, the image sensor 3 may combine pixel signals from three pixels 10 arranged side-by-side along the column direction and output the combined pixel signal to the control unit 4. Namely, the image sensor 3 may read out signals each obtained by combining signals from three pixels arranged along the column direction. In the example presented in FIG. 3, the image sensor 3 outputs a combined pixel signal obtained by combining the pixel signals from the pixel 10 (1, 1), the pixel 10 (2, 1) and the pixel 10 (3, 1), to the control unit 4. The pixel 10 (2, 1) is a pixel at the central position among the three combination target pixels 10. At the image sensor 3, the pixel signal readout (readout method) from the individual pixels 10 is controlled when generating a pixel signal by combining signals from a plurality of pixels 10 so as to obtain a pixel signal with the greatest weight applied to the pixel signal from the pixel 10 at the central position. The following is a more detailed explanation of the pixel signal readout method adopted in the second control mode.
