METHOD AND APPARATUS FOR DETECTING A DISK IS EXIST OR NOT IN A DISK TRAY FOR USE IN A DIGITAL VIDEO DISK PLAYER

摘要

PURPOSE: Deciding device and method for existence of a disk in a DVDP(Digital Video Disk Player) are provided to precisely decide existence of the disk through increasing reflecting amount by increasing output of a laser diode in case of a small optical amount. CONSTITUTION: An optical pickup unit(10) contains a laser diode to perform focus servo to pick up beam outputted from the laser diode and reflected on a disk(D). An optical amount detect unit(20) detects optical amount of beam from the optical pickup unit. A compensate unit(40) outputs a compensating signal for compensating a focus error. A pickup drive unit(50) drives the optical pickup unit to perform focus servo. A microcomputer(60) compares the optical mount signal with a reference signal for increasing output of the laser diode by the optical amount signal lower than the reference. A laser diode drive unit(70) increases output of the laser diode according to the microcomputer.