Patent ID: 6246659
Filing Date: 2001-06-12
Classification: G11B

Abstract:
A method of controlling laser light power to be used for recording information on an optical disk in accordance with a mark-length recording scheme using recording laser light power emitted from a laser diode driven by a recording signal including recording pulses, said method comprising the steps of:providing each of the recording pulses in a train of divided pulses, one of the divided pulses having a greater pulse width than other divided pulses, a smaller laser-driving current value being set for the one divided pulse having the greater pulse width than for the other divided pulses;detecting, as a finite value of laser-driving current for generating bottom laser light power, smaller than recordable-level laser light power, in a part or whole of a section in between the recording pulses of the recording signal, laser-driving current values both at a predetermined time corresponding to the one divided pulse having the greater pulse width and at a predetermined time corresponding to the bottom laser light power;controlling the laser-driving current values for the one divided pulse having the greater pulse width and for the bottom laser light power in such a manner that laser light power levels of the laser light power, detected by said step of detecting at the predetermined time corresponding to the one divided pulse having the greater pulse width and at the predetermined time corresponding to the bottom laser light power, correspond to respective predetermined reference values;determining a recording laser-driving current value to achieve a reference recording laser-light-power value predetermined for the other divided pulses having a smaller pulse width than the one divided pulse having the greater pulse width, based on the laser-driving current values controlled by said step of controlling and a driving-current vs. output-laser-light-power characteristic of said laser diode; andcontrolling laser-driving current for the other divided pulses to correspond to the recording laser-driving current value determined by said step of determining.