High density optical disk processing apparatus, method, and computer-readable medium

An optical disk having a record signal recorded on a carrier signal on a disk made of carrier grooves in a protruding and recessed pattern having a high frequency higher than or equal to a cut-off frequency, wherein

• a reproduction apparatus is used to read a TPP (Tangential Push-pull) signal obtained by frequency-shifting a superimposed signal having the carrier signal and the record signal superimposed with each other, the reproduction apparatus being further used to extract a high-frequency component signal from the record signal recorded on the optical disk by performing an operation of frequency-shifting the TPP signal to a high-frequency component range in the record signal recorded on the optical disk, wherein
• the operation is a process of multiplying the TPP signal with the carrier signal,
• the reproduction apparatus is used to perform the process of multiplying the TPP signal with the carrier signal in order to frequency-shift the TPP signal to the high-frequency component range in the record signal recorded on the disk, and
• the reproduction apparatus is further used to generate the reproduced signal by extracting the high-frequency component signal from the record signal recorded on the optical disk.

A non-transitory computer-readable medium having embodied thereon a program, which when executed by at least one processor of an information processing apparatus including a photo-detecting section configured to receive reflected light from a disk, and a signal processing section configured to generate a reproduced signal by performing signal processing on a light reception signal from the photo-detecting section, the disk being structured to have a record signal recorded on a carrier signal formed by carrier grooves in a protruding and recessed pattern having a high frequency higher than or equal to a cut-off frequency, the photo-detecting section having two split detectors A and B in a direction of tracks on the disk, causes the information processing apparatus to execute an information processing method comprising:

• causing the signal processing section to generate a TPP (Tangential Push-pull) signal made of a differential signal derived from detection signals from the detectors A and B, the TPP signal being obtained as a readout signal by frequency-shifting a superimposed signal having the carrier signal and the record signal superimposed with each other;
• and
• causing the signal processing section to generate the reproduced signal through extraction of a high-frequency component range from the record signal recorded on the disk by performing an operation of frequency-shifting the generated TPP signal to the high-frequency component range in the record signal recorded on the disk.