| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a beam irradiation apparatus capable of suppressing an influence of a laser beam (disturbance light) on a position detection signal, and enhancing the accuracy of the position detection signal. Ž<P>SOLUTION: The beam irradiation apparatus includes a PSD signal processing circuit 3 for generating a signal according to a servo-beam reception position based on an output signal from a PSD 308. The PSD signal processing circuit 3 has signal removal circuits 15, 16, 17, 18 for removing a disturbance signal generated when the laser beam irradiating a target area is partly incident on the PSD 308, from an output signal of the PSD 308. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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