| 摘要 |
PURPOSE:To reduce or to eliminate astigmatic aberration occurred in the light transmitted through a deflection optical element. CONSTITUTION:A total reflection mirror 35a is supported by a supporting member 34 through an adhesive 38 and a coil spring 36 and made to change the angle by means of an adjusting screw 37. In the state before the adhesive 38 is hardened, the total reflection mirror 35a is made to incline, the angle of the incident light to an objective lens 33 is made to change and the astigmatic aberration occurred in the light beam passing through an acoustic optical deflector 21 and the astigmatic aberration caused by making an oblique light beam incident on the objective lens 33 are made to cancel and the adhesive 38 is hardened after the completion of adjustment. |
