Patent ID: 6952387

Claim:
An optical disk playing apparatus for automatically discriminating one optical disk to be either of two types of optical disks which have different recording densities so as to play said one optical disk in accordance with the discriminated result, comprising: a pickup unit for irradiating reading light onto said one optical disk, and receiving reflected light from said one optical disk to output a light receiving signal; a servo device for controlling said pickup unit to perform at least a focusing servo operation for the reading light as a servo operation; a moving device for moving an irradiated position of the reading light by said pickup unit onto said one optical disk to cross tracks which are formed on said one optical disk; a tracking error signal generator for generating a tracking error signal in response to the light receiving signal from said pickup unit during the track crossing of the irradiated position; a binarizing device for comparing said tracking error signal with a threshold value; and a determining device for determining the type of said optical disk in accordance with a number of pulses output from said binarizing device within a predetermined period from start of the track crossing of the irradiated position.