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Optical pickup objective, optical pickup, and disk drive

A technology of optical head and objective lens, which is applied in the direction of optical recording head, beam guiding device, optics, etc., can solve the problem of converging laser light that is difficult to reach the diffraction limit, and achieve the elimination of diffraction efficiency reduction factors, suppression of manufacturing errors, and improvement of numerical aperture Effect

Inactive Publication Date: 2006-08-09
SONY CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The objective lens 201 formed by glass molding having an aspheric surface 201a in the conventional technology has difficulty in converging laser light at the diffraction limit due to the occurrence of chromatic aberration as described above.

Method used

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  • Optical pickup objective, optical pickup, and disk drive
  • Optical pickup objective, optical pickup, and disk drive
  • Optical pickup objective, optical pickup, and disk drive

Examples

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Embodiment Construction

[0055] Hereinafter, the objective lens used in the optical head device of the present invention, the optical head device and the optical disk device using the objective lens will be described with reference to the drawings.

[0056] The embodiment of the present invention shown below is applicable to an optical disc device having a track of about 0.6 μm to make the present invention narrower than the track pitch of recording tracks provided on a disc-shaped optical recording medium CD (Compact Disc). Pitch disc-shaped optical recording medium, for example, DVD (Digital Video Disc / Digital Versatile Disc) etc. by narrowing the track pitch of recording track to improve the disc-shaped optical recording medium of information recording density specification, carry out the recording of information, and Information recorded on the recording medium is reproduced.

[0057] First, an optical disc device using an optical head of the present invention using the objective lens of the prese...

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Abstract

Thepresent invention is an objective for an optical pickup used for recording or reproducing an information signal on or from an optical disk. The objective comprises a resin layer (21) and a glass lens (22). The resin layer (21) has an aspherical first surface (S1) and an aspherical second surface (S2)in order from the object side. At least either of the surfaces includes a diffraction surface. The lens has a spherical second surface (S2) and an aspherical third surface (S3). The chromatic aberration to a wavelength range within several nanometers from a reference wavelength of 420 nm or less is corrected on the image surface on the optical axis is corrected. The objective has a numerical aperture (NA) of 0.8 or greater. The objective focuses a laser beam close to the diffraction limit on the image plane.

Description

technical field [0001] The present invention relates to an objective lens for an optical head of an optical disc drive device for irradiating laser light onto an optical recording medium and recording and / or reproducing information, an optical head using the objective lens, and an optical disc drive device using the optical head, and relates to An objective lens for converging laser light onto a recording surface of an optical recording medium at a diffraction limit, an optical head using the objective lens, and an optical disc drive device using the optical head, Background technique [0002] As a recording medium for information signals, a non-contact high-density recording optical recording medium in which information is recorded and reproduced by irradiating laser light onto a recording surface is widely used. As for optical recording media, disk-shaped optical recording media (hereinafter referred to as "optical discs") are widely used due to advantages such as ease of ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G02B13/18G11B7/135G02B27/00
CPCG02B27/4238G02B5/1847G02B5/1895G02B27/0037G11B7/1353G11B7/1374G11B2007/13727G02B13/18
Inventor 高桥丰和日根野哲
Owner SONY CORP