Patent ID: 7272103
Filing Date: 2007-09-18
Classification: G11B

Abstract:
1. A laser power monitor device for an optical recording and/or reproducing apparatus having a laser diode and an automatic laser power control circuit, the laser power monitor device comprising: a photo diode unit to receive part of a light emitted from the laser diode and output a current proportional to optical power; a monitor circuit, to receive the current output from the photo diode unit, convert the received current into a voltage, and output the voltage to the automatic laser power control circuit, wherein the photo diode unit includes a plurality of photo diodes connected to the monitor circuit to supply current to the monitor circuit; and a switch unit that is installed between the photo diode unit and the monitor circuit, wherein the switch unit receives a signal on a current recording speed and switches to reduce the number of photo diodes supplying current to the monitor circuit as the recording speed is increased.