| 摘要 |
PROBLEM TO BE SOLVED: To eliminate irregular density of a read image by controlling light emission of a lamp and eliminating differences of accumulated light volume in each line without deviating from an optimum lighting condition held by a lamp that illuminates an original reading part and without complicating the circuit constitution of a light source part. SOLUTION: In an image reader for reading an electrical signal to an original image in a line unit by irradiating an original with an exposure lamp and receiving its reflected light by a photoelectric converter, an oscillation circuit of an inverter that turning on a lamp is synchronized with a line synchronizing signal for regulating reading start timing of each line and controlled. Also, the oscillation frequency of the inverter is set so as to make the number of lamp lighting pulses for one line cycle constant. COPYRIGHT: (C)2004,JPO
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