Patent ID: 7256379

Claim:
A photodetector, having a photosensitive region, in which pixels are arrayed two-dimensionally, and being used with a light source that illuminates light onto an object, wherein a single pixel is arranged by adjacently positioning on the same plane a plurality of photosensitive portions, each outputting a current that is in accordance with an intensity of light incident thereon and, in each plurality of pixels that are aligned in a first direction of the two-dimensional array, one photosensitive portion among the plurality of photosensitive portions making up each corresponding pixel is electrically connected to the same photosensitive portion of each of the other corresponding pixels and, in each plurality of pixels that are aligned in a second direction of the two-dimensional array, another photosensitive portion among the plurality of photosensitive portions making up each corresponding pixel is electrically connected to the same photosensitive portion of each of the other corresponding pixels, the photodetector comprising: a first signal processing circuit, detecting a luminance profile in the second direction based on differences between outputs, corresponding to charges accumulated in first groups of the photosensitive portions that are electrically connected across the pluralities of pixels aligned in the first direction over a first period wherein the light is illuminated onto the object by the light source, and outputs, corresponding to charges accumulated in the first groups of the photosensitive portions over a second period wherein the light is not illuminated onto the object by the light source; and a second signal processing circuit, detecting a luminance profile in the first direction based on differences between outputs, corresponding to charges accumulated in second groups of the photosensitive portions that are electrically connected across the pluralities of pixels aligned in the second direction over the first period, and outputs, corresponding to charges accumulated in the second groups of the photosensitive portions over the second period.