| 摘要 |
PURPOSE:To cause a seek speed to be high by scanning a laser beam deflected by an optical deflecting means through an objective lens to be telecentric to an image surface side over the inner and outer circumferences of an optical disk, irradiating and condensing the beam vertically to the signal recording surface of the optical disk. CONSTITUTION:The scanning of the laser beam projected on an optical disk 8 over the inner and outer circumferences of the optical disk 8 can be executed by turning-operating only a mirror 6 for scanning. This mirror 6 for scanning is light and the laser beam is scanned by the turning displacement of a little angle over the inner and outer circumferences of the optical disk 8. Accordingly, the scanning of the laser beam of a high-speed and satisfactory responsibility can be easily executed. Thus, without inviting the increasing of energy consumption or the enlargement of a device, the highly-speedy seek can be attained over the inner and outer circumferences of the optical disk 8. |
