Patent ID: 7190493
Filing Date: 2007-03-13
Classification: H04N

Abstract:
1. An image reading apparatus comprising: an image sensor including a plurality of photosensor elements; an optical system for inputting an optical image to the image sensor; a drive unit for driving the image sensor; a processing unit for converting groups of analog data outputted from the image sensor, into groups of digital data, and outputting image data expressive of the optical image on the basis of the groups of digital data; a white input unit for inputting a white reference image to the image sensor so as to output groups of analog data; a conversion unit for causing the processing unit to convert the groups of analog data outputted from the white input unit, into the groups of digital data the number of which is smaller than that of the photosensor elements of the image sensor; an inspection unit for inspecting a lowest density value of the groups of digital data; a setting unit for setting an operating environment in which the lowest density value of the groups of digital data becomes a density value within a predetermined range; and a control unit for controlling the optical system, the drive unit and the processing unit under the operating environment, and for causing the processing unit to output image data which express a subject image inputted to the image sensor.