| 摘要 |
PROBLEM TO BE SOLVED: To adjust the focus and the magnification of the image reader automatically with a simple configuration by obtaining information relating to the focus and the magnification based on a signal detected by a photoelectric conversion element and driving a lens and a mirror depending on the information. SOLUTION: A contrast detection circuit 10 detects a contrast signal of an output signal denoting an image formed on a CCD 9. In the case that the contrast signal does not satisfy the standards, the circuit 10 drives a lens motor drive circuit 11 to allow a lens drive motor 8 to move a lens 7. A magnification detection circuit 12 detects the magnification based on the output signal from the CCD 9. In the case that a magnification error is not within±1.5, the magnification detection circuit 12 calculates the movement amount of the mirror and activates a mirror motor driving circuit 13 to drive a mirror motor 6 thereby moving the mirror 5 by a prescribed amount. Thus, the accurate image reader is obtained with less focus adjustment error and lens error.
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