Optical disk device

Abstract

The optical disk apparatus is equipped with an optical system which irradiates a loaded optical disk with light, a photodetector which receives the reflected light from the optical disk in a plurality of regions and forms a plurality of reproduced signals meeting the quantities of the light received in the respective regions, a filter which receives the plurality of reproduced signals and outputs a plurality of processing signals decreased in the frequency components determined according to the lengths of the marks among the frequency components of the respective signals, a phase difference detector which detects the phase differences of the respective processing signals, a signal forming section which forms the TE signals indicative of the positional relations between the irradiation positions of the light and the tracks on the optical disk based on the phase differences, and a control section which forms a control signal based on the TE signals. The irradiation positions of the light are controlled to the direction crossing the tracks on the optical disk in accordance with the control signal.

Description

technical field [0001] The present invention relates to a technique for reproducing and / or recording information on various information carriers for reproduction (read only) and recording and reproduction (readable and writable). More specifically, the present invention relates to an optical disc device that controls a light spot to scan accurately on a track of an optical disc when the optical disc is irradiated with a light beam such as a laser to reproduce and / or record information. Background technique [0002] Optical discs such as digital versatile discs (Digital Versatile Disc: DVD) are attracting attention as information carriers capable of recording digital information. In recent years, since the amount of digital information to be recorded has continued to increase, higher densities have been demanded for optical discs. [0003] One or more tracks are set on the disc. For a read-only optical disc, information is recorded by an arrangement of pits and spaces forme...

AI Technical Summary

Problems solved by technology

As a result, if a high-density optical disc is reproduced, the detection error due to the small shift Δv of the cutting level becomes large and cannot be ignored.

[0018] In the conventional optical disc device, the portion where the amplitude of the reproduced signals A+C, B+D is small causes the detection error of the TE signal to increase, causing the quality of the TE signal to deteriorate.

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