Patent ID: 9071720
Filing Date: 2015-06-30
Classification: G07D,H04N

Abstract:
1. An image reading apparatus comprising: an illumination unit to irradiate a sheet that is conveyed by a conveyance unit with visible light and infrared light; an imaging unit to receive visible light and infrared light reflected from the sheet and to capture a visible image and an infrared image, the imaging unit including a first imaging portion to take the visible image and a second imaging portion to take the infrared image; and a background member including an infrared light low reflective part that is positioned within an imaging range of the imaging unit so as to overlap at least a side edge portion of the sheet and that diffusely reflects visible light and reflects infrared light at a lower reflectance than the sheet; an image processing unit to detect an edge of the sheet based on the captured infrared image and to correct the visible image based on the detected edge; an image characteristic calculating unit to calculate characteristics from each of the visible images taken by the first imaging portion and the infrared image taken by the second imaging unit; and an identification unit to identify the sheet by comparing the characteristics calculated by the image characteristic calculating unit with parameters read out from a dictionary storing unit, respectively, wherein the background member further includes: a light diffusing/reflecting member that is provided in a central portion in a direction orthogonal to a conveyance direction of the sheet and that diffusely reflects visible light and infrared light, and the image processing unit corrects the visible image based on visible light reflected from the light diffusing/reflecting member and corrects the infrared image based on infrared light reflected from the light diffusing/reflecting member.