Optical disc device

An optical disc device and optical disc technology, which can be used in beam guiding devices, optical detectors, optical recording heads, etc., and can solve problems such as hindering track control
CN101401159AInactive Publication Date: 2009-04-01PANASONIC CORP
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
PANASONIC CORP
Publication Date
2009-04-01
Estimated Expiration
Not applicable · inactive patent

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Abstract

Stable tracking with a small control error is performed at the time of reproducing records of a multilayer disc, without being affected by stray light reflected by signal planes other than focusing signal planes. A light splitting element of an optical disc device is provided with first areas (21c-24c) including an optical axis position (20) of light inputted from an objective lens; and second areas (21a-24a, 21b-24b) at positions away from the optical axis in the peripheries of the first areas. A detecting plane (9a) of a photodetector is provided with first detecting areas (97, 98) for detecting incoming light from the first areas; and second detecting areas (95, 96) for detecting incoming light from the second areas. A tracking error signal is detected by the second detecting areas. When the optical disc has a plurality of signal planes, light, which is reflected by the signal planes other than the focusing signal planes and entered the photodetector from the first areas, does not enter the second detecting areas.
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Description

technical field

[0001] The present invention relates to an optical disc device for recording a signal on an optical disc or for reproducing a signal recorded on the optical disc. Background technique

[0002] As a prior art, for example, an optical disc device is disclosed in Japanese Patent Laid-Open No. 2000-132848 (Patent Document 1). use below figure 1 , Figure 7 with Figure 8 Based on this prior art example, a part of it will be modified and described.

[0003] figure 1 (a) shows a cross-sectional structure of main parts of an optical disc device of a prior art example. Such as figure 1 As shown in (a), the conventional optical disc device has a photodetection substrate 9 and a light source 1 mounted on the photodetection substrate 9 . The light source 1 is, for example, a semiconductor laser or the like. Also, this optical disc device has a collimating lens 4, a polarizing hologram substrate 2, a 1 / 4 wavelength plate 3, and an objective lens 5 on the optical ...

Claims

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