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Device for reading and/or writing optical recording media

An optical recording medium and technology for recording media, which are applied in optical recording heads, optical recording systems, recording/reproducing by optical methods, etc., can solve the problems of interference and high production cost of beam combining parts, and achieve fewer integration and debugging steps. Effect

Inactive Publication Date: 2006-05-03
THOMSON LICENSING SA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This known device has the disadvantage that the beam combining part comprising the prism and the holographic combination is expensive to produce
Also, holography cannot be optimally matched to the different characteristics of light sources producing different wavelengths, which can lead to more or less severe interference

Method used

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  • Device for reading and/or writing optical recording media
  • Device for reading and/or writing optical recording media
  • Device for reading and/or writing optical recording media

Examples

Experimental program
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Embodiment Construction

[0033] FIG. 1 shows the beam path in an optical scanner 3 of a device for reading from and / or writing to an optical recording medium 1 , which has two laser diodes LD1 , LD2 . A so-called dual laser diode comprises an arrangement of two individual laser diodes LD1 , LD2 integrated in a common frame 2 . For use in the field of optical scanners 3 for reading from and writing to optical recording media 1, the first laser diode LD1 operates at a first wavelength λ 1 =650nm emits light, and the second laser diode LD2 emits light at the second wavelength λ 2 =780nm luminescence. Second wavelength λ 2 In the case of the rays used for reading and writing earlier CD formats, the first wavelength λ 1 For newer DVD formats. As a result of the various requirements of the different disc formats, all components of the scanner 3 have to be optimized to the two wavelengths λ 1 ,λ 2 . Thus, for example, the collimator lens 4 should have as little divergence as possible and the objective...

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Abstract

The present invention relates to an appliance for reading from and / or writing to optical recording media 1 having a first laser diode LD1 for producing a first scanning beam AS1 at a first wavelength lambda1 and having a second laser diode LD2 for producing a second scanning beam AS2 at a second wavelength lambda2, with the scanning beams AS1, AS2 running along a common optical axis 9, scanning an information layer 6 on the recording medium 1 and falling on a single photodetector 8 in order to produce an information signal IS, with a beam combination element being arranged at one point on the optical axis 9. According to the invention, the beam combination element is a diffraction grating 12.

Description

technical field [0001] The present invention relates to an apparatus for reading from and / or writing to an optical recording medium using scanning beams of different wavelengths moving along a common optical axis, scanning the recording medium and detecting it by a single photodetector . In particular, the device has an optical scanner for reproducing and recording data on a rewritable optical disc. Background technique [0002] Optical scanners capable of playing back and writing to digital versatile discs (DVD) and compact discs (CD) require two different laser wavelengths. For this purpose, CD-compatible DVD players and recorders are equipped with two different laser diodes. This separate structure leads to an increase in economical costs due to the additionally required optical components. More recently, a so-called dual laser diode has been developed as a way to reduce the number of required components. This consists of two laser diodes of different wavelengths moun...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G11B7/135G02B5/18G11B7/00G11B7/0045G11B7/1353
CPCG11B7/1353G11B2007/0006
Inventor 索伦·达姆巴赫哈马特·里克特
Owner THOMSON LICENSING SA