Patent ID: 6341117
Filing Date: 2002-01-22
Classification: G11B

Abstract:
An apparatus for controlling power to a laser diode in optical recording media, the apparatus comprising:a photo diode; a laser diode; an interface unit that interfaces with an external processor; a power level decoding unit that decodes an address relating to one of the optical recording media from said interface unit, and demultiplexes data corresponding to target power levels; a power level control unit, driven by a clock signal, that receives the data corresponding to the target power levels from said power level decoding unit and outputs a signal indicative of each of the target power levels; a pulse generating unit generating a predetermined type of a pulse upon receiving data from said interface unit; a time delaying unit delaying the pulse output by said pulse generating unit; an automatic diode power control unit that converts the data corresponding to each target power level from said power level decoding unit into analog data and keeps an output level of said laser diode stable by selecting a required power level using the time delayed output from said time delaying unit and outputting a power level compensation signal; and a laser diode driving unit that generates a driving signal for said laser diode based on the power level compensating signal from said automatic diode power control unit and the pulse outputted from said pulse generating unit.