Optical pickup device, optical recording and/or reproducing apparatus using the same, and method for detecting tracking error signal

Abstract

An optical pickup and an optical recording and / or reproducing apparatus employing the optical pickup, wherein the optical pickup includes: a light source; an objective lens to collect and focus an incident beam on an information storage medium; a holographic grating to split light emitted by the light source into a main beam and first and second sub-beams by diffraction and to provide, or create, a continuously changing wavefront in the first and second sub-beams to reduce the amplitude of an AC component of a sub-push-pull (SPP) signal of the first and second sub-beams; and a photodetector to receive the main beam and the first and second sub-beams that are focused on and reflected from the information storage medium and to obtain a main push-pull (MPP) signal of the main beam and a SPP signal of the first and second sub-beams.

Description

[0001] This application claims the rights and interests of Korean Patent Application No. 10-2005-0027556 ​​filed with the Korean Intellectual Property Office on April 1, 2005, the disclosure of which is incorporated herein by reference. Technical field [0002] Aspects of the present invention relate to an optical recording and / or reproducing apparatus, and more specifically, to an optical pickup designed to realize compatible tracking servo between optical discs with different track pitches, and An optical recording and / or reproducing apparatus using the optical pickup and a method of detecting a tracking error signal. Background technique [0003] The emergence of optical discs of various specifications requires an optical disc recording and / or reproducing device designed to achieve compatibility between discs of different specifications. For example, DVD±R / RW type discs use the same light source wavelength and objective numerical ap...

AI Technical Summary

Problems solved by technology

However, since the position at which the sub-beam is focused is fixed during the design and assembly of the optical pickup using the DPP method, it is generally difficult to realize the tracking servo of an optical disc having a track pitch different from the specific track pitch set for the optical pickup to maximize Perform recording / reproduction optimally

Therefore, it is difficult to achieve compatibility with optical discs with different track pitches using the general DPP method

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