Patent ID: 7046606

Claim:
An optical disc drive loadable with an arbitrarily selected one of optical discs of multiple types including a first optical disc with grooves and a second optical disc with no grooves, the optical disc drive comprising: an optical system for irradiating the recording side of the loaded optical disc with a laser beam; a light detecting section, which receives reflected light from the optical disc to generate a first output signal representing the quantity of at least a part of the light reflected from an inside portion of the optical disc and a second output signal representing the quantity of at least a part of the light reflected from an outside portion of the optical disc; a spot location control section for shifting the spot location of the laser beam on the optical disc across recording tracks on the optical disc; and a disc type recognizing section for determining, by an upper envelope signal of at least one of the first and second output signals, whether the loaded optical disc has grooves or not.