Patent ID: 7248553
Filing Date: 2007-07-24
Classification: G11B

Abstract:
1. A laser power control device for use in an optical recording and/or reproducing apparatus that records data on and/or reproduces data from an optical recording medium by using a laser diode, the device comprising: a photodiode which receives light radiated from the laser diode and outputs a current; a current-to-voltage converter which converts the current into a voltage and outputs the voltage; a peak-holder which peak-holds the voltage and outputs the peak-held voltage when pits are formed on the optical recording medium, and outputs the voltage without peak-holding when a space between pits of the optical recording medium is formed; a first sampler-and-holder which samples and holds an output of the peak-holder, and outputs a voltage corresponding to peak power; a second sampler-and-holder which samples and holds an output of the peak-holder, and outputs a voltage corresponding to elimination power; a peak current setter which sets a peak current that flows into the laser diode; an elimination current setter which sets an elimination current that flows into the laser diode; a bias current setter which sets a bias current that flows into the laser diode; and a calculator which calculates setting values of the peak current, the elimination current, and the bias current, based on the voltage corresponding to the peak power and the voltage corresponding to the elimination power.