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Objective lens unit, optical pickup and optical information device

A technology of optical pickup and objective lens, which is applied in the direction of beam guiding device, information storage, recording information storage, etc. It can solve problems such as difficulty in meeting specifications, and achieve the effects of suppressing resonance, reducing distance, and stabilizing control

Active Publication Date: 2008-08-13
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when multiple objective lenses are supported by the objective lens holder, it is generally difficult to meet such different specifications because there is only one actuator for driving the objective lens holder.

Method used

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  • Objective lens unit, optical pickup and optical information device
  • Objective lens unit, optical pickup and optical information device
  • Objective lens unit, optical pickup and optical information device

Examples

Experimental program
Comparison scheme
Effect test

no. 1 Embodiment approach

Next, a first embodiment of the optical pickup according to the present invention will be described. 1 and 2 are schematic side views and perspective views showing the optical pickup 101 .

[0066]

In FIG. 1, a direction T is a tracking direction, and a direction F is a focusing direction. In addition, the direction Y is a direction perpendicular to the tracking direction. The optical pickup 101 is arranged so that these directions coincide with the tracking direction, the focusing direction, and the direction perpendicular to the tracking direction of the optical information device (optical disk device). However, the direction Y and the direction T may be arranged to coincide with the tracking direction of the optical information device and the direction perpendicular thereto.

[0067]

The optical pickup 101 is capable of recording and reproducing at least one of the three optical discs 32, 35, 46 having different recording densities. The optical disks 32, 35, and 46 ar...

no. 2 Embodiment approach

In an optical pickup provided with a plurality of objective lenses, it is necessary to provide a plurality of through-holes serving as passages of light beams in the lens holder. In particular, in order to record and reproduce an optical disc with a high recording density, it is necessary to use an objective lens with a large numerical aperture. Therefore, the through hole also becomes larger. Since this type of lens holder has a large through hole, its rigidity is low and it tends to resonate at a predetermined frequency. In the optical pickup of the present embodiment, an objective lens driving device having a structure for suppressing deterioration of servo performance due to lens holder resonance is provided.

[0144]

12 and 13 are a perspective view and an exploded perspective view showing an objective lens driving device using the optical pickup of this embodiment. As in the first embodiment, arrows F, T, and Y indicate the focusing direction, the tracking direction, ...

no. 3 Embodiment approach

In this embodiment, an objective lens driving device having an appropriate structure for realizing the distance between the two objective lenses described in the second embodiment will be described.

[0170]

21 and 22 are a plan view and an exploded perspective view showing the objective lens driving device 103 according to this embodiment. The direction T, the direction Y, and the direction F shown in FIGS. 21 and 22 represent the tracking direction, the focusing direction, and the tangential direction of the optical disc, as in the second embodiment.

[0171]

The objective lens driving device 103 includes a movable body including an objective lens 301, an objective lens 302, a lens holder 303, focusing coils 304a to 304d, and tracking coils 305a and 3005b.

[0172]

The lens holder 303 is made of resin, and supports the objective lens 301 and the objective lens 302 . The objective lens 301 is used for recording and reproducing optical discs with low recording density su...

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Abstract

An objective lens unit is provided with a first objective lens (41) and a first lens holder (2) for supporting the first objective lens (41), and the first lens holder (2) is composed of a material which passes through ultraviolet rays. Preferably, the first lens holder (2) includes a through hole, which has first and second openings (2a, 2b) and passes through light entering the first objective lens (41); and an opening limiting section (3) protruded in the center axis direction of the through hole along the circumference direction in the through hole. Furthermore, preferably, the first objective lens (41) is supported to cover the first opening (2b), and the opening limiting section (3) guides light, which enters the opening limiting section (3) from the second opening (2a), in a direction to be away from an optical axis of the first objective lens.

Description

technical field [0001] The present invention relates to an optical information device for optically recording and reproducing information, and an optical pickup and an objective lens unit used in the optical information device. In addition, the present invention also relates to an applied device equipped with an optical information device. field Background technique [0002] As an information recording medium capable of recording large-capacity information, optical discs are widely used, and with the advancement of technology, optical discs with higher recording density are coming out continuously. [0003] The compact disc (CD) was first popularized, and then the digital versatile disc (DVD) became popular. Because DVD can record information with a recording density about 6 times that of CD, it is possible to record large-capacity data on one DVD. Therefore, it is especially used for recording movie information with a large amount of information. In addition, in r...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G11B7/09G11B7/135
CPCG11B7/1374G11B2007/0006
Inventor 金马庆明若林宽尔佐野晃正田中俊靖松崎圭一和田秀彦
Owner PANASONIC CORP
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