JPH04121824A - Objective lens driving device - Google Patents

Abstract

PURPOSE:To obtain an objective lens driving device in which the driving force of a tracking coil can be accurately applied in a tracking direction and also, displacement without generating optical axis collapse can be performed by accurately performing the positioning of the tracking coil, a focusing coil, and a supporting arm member with metallic mold, molding movable member integrally with a holder. CONSTITUTION:The positioning of the tracking coil 22, the focusing coil 21, and the supporting arm member 12 are performed by loading them on the metallic mold, and the movable member 11 and the holder 12 are molded and fixed integrally so as to be connected with the supporting arm member 23. By forming a device in such a manner, the positioning of the tracking coil 22 and that of the supporting arm member 23 can be accurately performed. Thereby, the displacement of a driving member in which the driving force in an accurate direction can be obtained and no optical axis collapse occurs can be accurately performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an objective lens driving device in an optical information recording device.

[Conventional technology]

Conventionally, in this type of optical information recording device, in order to accurately focus the laser light emitted from a semiconductor laser onto the medium and perform optical recording and reproduction, the objective lens is set in a focus direction perpendicular to the medium. It also has a support mechanism that is movable in the track direction, which is the radial direction, and a drive mechanism. These mechanisms generally utilize support using springs or the like and electromagnetic force from magnets and coils.

FIG. 3 is an exploded perspective view of a movable member, a support arm member, and a holder showing an example of the conventional art.

In FIG. 3, the movable part is a bobbin 34 that holds the lens.
The focus coil 36 is wound on the holder 32, the support arm member 33, and the movable member 31 are bonded and fixed after the previously wound track coil 35 is positioned and fixed using a jig to form the movable member 31. Was.

[Problem to be solved by the invention]

In the above-mentioned conventional objective lens drive device, the track coil is crimped onto the focus coil wound around the bobbin using a jig to position and fix it. There is a risk that the track coil cannot be accurately positioned, and there is also a risk that the support arm member cannot be accurately adhesively fixed in parallel due to variations in the mounting position accuracy of the movable member and the support arm member of the holder.

In other words, if the track coil is not positioned accurately with respect to the bobbin, the magnitude and direction of the driving force generated by the magnetic field and current will be incorrect, making it impossible to drive in the accurate track direction, and the four support arms If adhesive fixation is not performed with the members accurately parallel, there is a problem in that the movable member cannot be displaced without tilting the optical axis.

SUMMARY OF THE INVENTION An object of the present invention is to provide an objective lens driving device in which the driving force of a track coil can act accurately in the track direction and displacement can be performed without tilting the optical axis.

[Means for Solving the Problems] The objective lens driving device of the present invention includes a movable member that holds an objective lens that irradiates a recording medium with a laser beam, and a movable member that is fixed to the movable member and moves the movable member in the track direction and the focus direction. In an objective lens drive device including a coil to be driven and a magnetic circuit consisting of a magnet and a yoke constituting a fixed member, a track coil, a focus coil, and a support arm member are loaded into a mold, and the movable member and holder are attached to the movable member and the holder. It is characterized by being integrally molded and fixed so as to be connected by a support arm member.

〔Example〕

Next, the present invention will be explained with reference to FIGS. 1 and 2.

FIG. 1 is an overall perspective view showing an embodiment of the objective lens driving device of the present invention, and FIG. 2 is an exploded perspective view of a track coil, a focus coil, and a support arm member that are integrally formed with the movable member in FIG. 1. be.

In this embodiment, the track coil 22, focus coil 21, and support arm member 23 are loaded into a mold and positioned, and the movable member 11 and holder 12 are mounted on the support arm member 23.
They are integrally molded and fixed so that they are connected. In this way, the track coil 22 and support arm member 23 can be accurately
can be positioned.

〔Effect of the invention〕

As explained above, the present invention accurately positions the track coil, focus coil, and support arm member using a mold, and integrally molds the movable member and the holder. The support arms are accurately positioned in a parallel position without being twisted, allowing for driving force in an accurate direction and accurate displacement of the driving member without tilting the optical axis. become.

In other words, the irradiation of the laser beam onto the recording surface is ensured, which has the effect of increasing the reliability of recording and reproducing information.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view showing an embodiment of the objective lens driving device of the present invention, FIG. 2 is an exploded perspective view of a track coil, a focus coil, and a support arm member integrally molded on the movable member in FIG. FIG. 3 is an exploded perspective view of a movable member, a support arm member, and a holder showing an example of the conventional art. 11.31... Movable member, 12.32... Holder,
21.36... Focus coil, 22.35...
Track coil, 23. 33... Support arm member, 3
4...Bobbin.

Claims (1)

[Claims] A magnetic circuit consisting of a movable member that holds an objective lens that irradiates a recording medium with a laser beam, a coil that is fixed to this movable member and drives the movable member in the track direction and a focus direction, and a magnet and a yoke that constitute the fixed member. In the objective lens drive device, a track coil, a focus coil, and a support arm member are loaded into a mold, and the movable member and the holder are integrally molded and fixed so as to be connected by the support arm member. objective lens drive device.