Patent ID: 7274640

Claim:
A disc type determining apparatus usable in a disc recording and/or reproducing apparatus in which vibrations generated by rotations of a disc occur in a focus and tracking control actuator, the disc type determining apparatus comprising: an error gain adjusting unit which adjusts an amplitude of a focus and tracking error which occurs in a focus and tracking control loop, in order to maintain the amplitude of the focus and tracking error constant; a loop gain adjusting unit which, in order to compensate for a gain difference of the actuator, compares a closed loop phase of the focus and tracking control loop and a predetermined reference closed loop phase, and maintains a gain of the focus and tracking control loop constant using the comparison; a vibration measuring unit which measures vibrations using an error adjusted by the error gain adjusting unit and the loop gain adjusting unit, and an output of a controller which controls the focus and tracking error compensated by the adjusted focus and tracking error; and a disc type determining unit which determines a type of the disc, the disc type determining unit to extract a predetermined signal from the measured vibrations, measures a deflection, an eccentricity, and a mass eccentricity of the disc using the extracted predetermined signal, and identifies the disc as being one of a deflection-type disc, an eccentric-type disc, and a mass eccentric-type disc.