| 摘要 |
PURPOSE:To execute focusing and tracking with one element by constituting a pick-up with using a piezoelectric-element, a displacement enlarging mechanism, a deflector to use a surface acoustic wave and detector. CONSTITUTION:A light emitting from a semiconductor laser 2 is conducted to a thin film wave conducting path 1 and a diffusing light is changed to a parallel light by passing through a geodetic lens 3. Then, the light is emitted to the external part of the optical conducting path 1 by a diffraction grating 5 and the focusing is executed on an optical disk. The light irradiating a disk 9 is reflected and returned to the wave conducting path 1. An optical detector 6 is prepared in the position of the returning light. Then, the reflected light is detected and focus dislocation is detected. An input to be proportional to a detecting signal is added to a piezoelectric-element 7 and by transmitting the displacement of the element to a lever 8, the displacement is enlarged. The whole wave conducting path 1 is parallelly moved up and down by the operation of this lever 8 and a focusing position is made coincident. Concerning track dislocation, surface acoustic wave 10 is displaced by the detecting signal and a wave conducting light is diffracted. Then, control is executed. |
