| 摘要 |
PURPOSE:To allow the exact adjustment of a tracking error signal by one- dimensionally moving only the light shielding member without requiring a member for moving sensors to the outside of the optical head. CONSTITUTION:An incident luminous flux 108 on a tracking error detecting part is passed through the light shielding plate 103 having two apertures in the part where the modulation by grooves is large and the incident light rays of respective apertures are condensed to the two-split sensors 105 by a condenser lens 104 to the sensors. The light shielding plate 103 is previously so constructed that the plate is moved parallel with the line connecting the apertures and positioned by means of a screw 102 and spring 106 for adjustment. A head chassis 101 is so limited in the grooves so as not to move except in the direction where the plate is moved by the adjusting screws. The light shielding plate 103 is, therefore, regulated only in the direction where the apertures line up so that the plate makes one-dimensional movement. The exact adjustment of the tracking error signal is executed in this way. |
