Patent ID: 7558173

Claim:
A disk device which performs recording and reproduction of an audio-visual signal for an optical disk, comprising: a determination unit for determining whether an optical disk loaded into the disk device is an unrecorded disk; a reading unit for reading arbitrary ASCII code recorded in advance at the head of an ECC block of a PCA on the optical disk, when the determination unit determines that the optical disk loaded into the disk device is an unrecorded disk; and an adjustment unit for appropriately adjusting a defocused positioning of an optical pickup so that jitter of an RF signal read by the optical pickup is minimized at the head of the ECC block, when the arbitrary ASCII code is recorded in advance at the head of the ECC block of the PCA on the optical disk, for recording arbitrary ASCII code at the head of the ECC block of the PCA on the optical disk as a test, and appropriately adjusting the defocused positioning of the optical pickup, so that jitter of an RF signal read by the optical pickup is minimized at the head of the ECC block, when the arbitrary ASCII code is not recorded at the head of the ECC block of the PCA on the optical disk, and for appropriately adjusting the defocused positioning of the optical pickup, so that jitter of an RF signal read by the optical pickup is minimized in a recorded area of the optical disk, when the determination unit determines that the optical disk loaded into the disk device is not an unrecorded disk.