Patent ID: 7512057

Claim:
A laser pulse controlling circuit that is connected with a controlling unit having a first illumination level setting unit that sets a first illumination level of a laser device to erase information recorded in an optical disk, and a second illumination level setting unit that sets a second illumination level of the laser device to record information into the optical disk, and that, when the laser device is driven with laser pulses having the first and the second illumination levels, causes the first and the second illumination level setting units to set the first and the second illumination levels corresponding to a predetermined ratio of the first illumination level to the second illumination level, wherein the laser pulse controlling circuit, based on regularity that the relation between: a manipulated variable for causing the second illumination level setting unit to execute adjustment of the second illumination level; and the inverse of the ratio, with reference to the first illumination level, is a straight line that necessarily passes one point for a predetermined first illumination level, and that a slope of the straight line is proportional to the predetermined first illumination level, calculates the manipulated variable that is correlated with the first illumination level corresponding to the optical disk, and with the inverse of the ratio, and causes the second illumination level setting unit to set the second illumination level corresponding to the calculated manipulated variable.