| 摘要 |
PROBLEM TO BE SOLVED: To actualize an image reader which can obtain a read image faithful to a document image and free of distortion and unevenness by driving a DC motor at a fixed speed matching the document to be read and has no position shift when a read is started, stopped, and restarted. SOLUTION: A speed control circuit 15 performs feedback control over the DC motor 14 so that time intervals measured by a pulse interval measuring circuit 9 are synchronized with time intervals of an interval setting register 10, and then the DC motor 14 is driven at the fixed speed. While a counter 12 counting signals from an encoder 8, the signal outputted from a CCD driving circuit 11 to a read part 20 is timed to the signal generation of the encoder 8 after the speed of the DC motor 14 becomes stable; when the count value of the counter 12 reaches a specific value, the actual read is started to prevent a position shift.
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