Patent ID: 6721261
Filing Date: 2004-04-13
Classification: G11B

Abstract:
An information recording/reproducing apparatus comprising:a semiconductor laser; a laser driver which drives the semiconductor laser to cause the semiconductor laser to emit light; an optical system which focuses the light emitted from the semiconductor laser on an information recording medium for use in optically recording information on and/or optically reproducing information from the information recording medium; a photodetector which detects light reflected from the information recording medium, and outputs a reflection light signal; a modulation circuit which modulates information in accordance with a predetermined rule, and outputs a binary signal representing the modulated information; and a calculation/control circuit which controls the modulation circuit; wherein the laser driver includes a delay circuit; wherein the laser driver receives the binary signal outputted from the modulation circuit, generates a recording current signal corresponding to the binary signal through the delay circuit, and transmits an output of the delay circuit to the calculation/control circuit as a monitor signal; and wherein the calculation/control circuit generates a timing signal for sampling and holding the reflection light signal outputted from the photodetector based on the monitor signal.