Patent ID: 7557858

Claim:
An image processing device comprising: an imaging unit that picks up an image; an image density recognizer that recognizes density of the image; and an exposure controller that in an exposure control period automatically controls an exposure of the imaging unit based on the density recognized, wherein the exposure control period includes at least a maximum exposure period during which the exposure is set to a maximum exposure, a minimum exposure period during which the exposure is set to a minimum exposure, and a normal exposure period during which the exposure is set to in between the maximum exposure and the minimum exposure; and a problem recognizer that determines any one of whether the imaging unit is abnormal and whether an environment is unsuitable for picking up an image by the imaging unit based on densities of images, which are recognized by the image density recognizer, that are picked up during the maximum exposure period, the minimum exposure period, and/or the normal exposure period, wherein the maximum exposure period, the minimum exposure period, and the normal exposure period have substantially same time length and appear in a predetermined order in the exposure control period.