| 摘要 |
PURPOSE:To correct securely a deviation in the irradiation position of a laser beam due to a deviation in the light emission point of a semiconductor laser by providing a control circuit which sends a drive control signal corresponding to the output signal of a beam position detecting means to an optical path moving means. CONSTITUTION:When the semiconductor laser 10 shifts in light emission point position, the laser beam 11 on a scanned body 17 shifts in position from a specific scanning position. The shifting position corresponds to the shifting position (deviation from specific incidence position) of a beam 11' on an optical position detector 21, so the beam position signal S2 outputted by the detecting circuit 21 indicates the shifting position of the laser beam 11 on the scanned body 17. This beam position signal S2 is inputted to a control circuit 23. An X-axis driver 32 and a Y-axis driver 33 input drive control signals S3 and S4 from the control circuit 23 respectively and drive an X-axis motor 27 and a Y-axis motor 31 to obtain the quantity of movement of a correcting lens which eliminates the shift in scanning position of the laser beam 11 indicated by the beam position signal S2.
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