Patent ID: 8036083

Claim:
An optical disk device, comprising: an examination means which, when an optical disk is loaded into the optical disk device, rotates said optical disk, irradiates laser light from a pickup head upon said optical disk, and examines a first physical characteristic of said optical disk; a servo means which starts, based upon said first physical characteristic, servo control for keeping said optical disk at a target rotational speed or a target RPM, and for tracking the irradiation position and the focused position of said laser light along a track upon which data is recorded; a read means, incorporating said examination means, which, under said servo control based upon said first physical characteristic, reads from said optical disk type information which specifies the type of said optical disk; and a control means which decides whether or not a second physical characteristic of said optical disk, which is determined as a standard for the type of said type information read by said read means, and said first physical characteristic, agree with one another; and wherein said control means: if it has been decided that said first physical characteristic and said second physical characteristic agree with one another, commands said read means to read replay data from said optical disk; and if it has been decided that said first physical characteristic and said second physical characteristic do not agree with one another, commands said read means to read replay data from said optical disk, under said servo control based upon said first physical characteristic.