COMPATIBLE OPTICAL PICKUP APPARATUS

摘要

PURPOSE: A compatible optical pickup device is provided to adopt a DVD(Digital Versatile Disk and a CD(Compact Disk) family including a CD-R(Compact Disk-Recordable) compatibly. CONSTITUTION: A first LD(Laser Diode,11) emits laser beams(11a) of 650nm to read/write data of a DVD(30a). The laser beam of the first LD are focused on the recording face of the DVD by an objective lens(29). A second LD(13) emits laser beams(13a) of 780nm to read/write data of a CD(30b). The laser beams are focused on the recording face of the CD. The objective lens focuses the incident beams to form optical spots on each recording face. A hologram element(23) transmits the laser beams from the LDs. A beam splitter(25) changes an optical path of the second beams. A first photodetector(15) detects data signals and error signals from the first beams reflected from the DVD. A second photodetector(35) detects the same signals from the second beams reflected from the CD. Therefore, an optical pickup system reads/writes data of disks having different thickness.