JPH0652560A - Driving device for objective lens - Google Patents

Abstract

PURPOSE:To shorten the distance from an objective lens to a fixed section in a spring-supported type objective lens driving device so as to house the device in the window frame of an optical disk cartridge. CONSTITUTION:An objective lens 1 is held at the central part of a three- dimensional mobile body 2 along the direction of tacks and the mobile body 2 is supported at four points by means of four plate springs 3a-3d for focusing which are arranged in parallel with each other. The end sections of the springs 3a-3d on the opposite side to the mobile body 2 are connected to a fixed supporting section 6 by using one plate spring 5 for tracking. The spring 5 is arranged in parallel with the direction of tracks at the central part of a repeating plate 4 and both ends of the spring 5 are connected to the section 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device used in an optical disk device.

[0002]

2. Description of the Related Art The structure of a conventional objective lens driving device will be described with reference to FIG.

In FIG. 2, reference numeral 1 denotes an objective lens of an optical head used in an optical disk device, and the objective lens 1 is fixedly held by a movable body 2. This movable body 2 is 4
The focusing direction (vertical direction in FIG. 2B) and the track direction (FIG. 2A) are applied to the fixed portion 6 via the focusing leaf springs 3a to 3d, the relay plate 4, and the tracking leaf spring 5. It is supported so that it can move vertically.

That is, four focusing leaf springs 3a
3d, one end thereof is fixed to both ends of the movable body 2 in the focus direction on both sides in the track direction, the width direction thereof is orthogonal to the focus direction, and the other ends of the relay plate 4 are parallel to each other in the focus direction. Fixed to. Furthermore, 1
One side of the leaf spring 5 for tracking is fixed to the relay plate 4 and the other side is fixed to the fixing portion 6 so as to be orthogonal to the leaf surfaces of the leaf springs 3a to 3d for focusing.

[0005]

In this conventional objective lens driving device, a fixed support portion in which a movable body, an objective lens, a relay plate and the like are arranged in a direction opposite to the movable body via one tracking leaf spring. Was linked to. Therefore, there is a problem in that the distance from the objective lens to the fixed support portion becomes long and it cannot enter the window frame of the cartridge of the optical disc medium.

[0006]

SUMMARY OF THE INVENTION An objective lens driving device according to the present invention comprises a movable body which holds the objective lens at a central portion along the track direction, and a movable body which supports the movable body at four points at respective end portions and is parallel to each other. 4 leaf springs for focusing,
In an objective lens driving device including one tracking leaf spring, which connects the ends of these four focusing leaf springs located on the opposite side to the movable body to a fixed support through a relay plate, The one tracking leaf spring holding the relay plate is arranged in parallel to the track direction and in the center of the relay plate, and both ends of the one tracking leaf spring are fixed support portions. It is composed by connecting.

[0007]

The present invention will be described below with reference to the drawings.

FIGS. 1A, 1B and 1C are a plan view, a front view and a side view of an embodiment of the present invention.

Objective lens 1 in the embodiment shown in FIG.
The arrangement of the movable body 2, the focusing leaf springs 3a to 3d, and the relay plate 4 is the same as in the conventional example of FIG. The difference from the conventional example of FIG. 2 is the arrangement of the tracking leaf spring 5 and the method of supporting the same. These differences will be described in detail below.

Referring to FIG. 1A, the tracking leaf springs 5 are arranged parallel to the track direction. Explaining with reference to FIG. 1C, the center portion of the tracking leaf spring 5 is used as a connecting portion with the relay plate 4, and both ends of the tracking leaf spring 5 are supported by the fixing portions 6. Therefore, FIG.
As shown in (b), the fixed portion 6 is the leaf spring 5 for tracking.
Since it is arranged in the same direction as the movable body 2, the length in the direction perpendicular to the track direction is the distance from the movable body 2 to the relay plate 4, and the size can be reduced.

[0011]

As described above, according to the present invention, the arrangement of the tracking leaf springs is changed to the direction orthogonal to the conventional one.
Moreover, since the fixed portion is arranged in the same direction as the movable body with respect to the leaf spring for tracking, the distance from the objective lens to the fixed portion is shortened, so that the track direction and the vertical direction can be downsized, and the optical disc medium It has an effect that it can be put in the window frame of the cartridge.

[Brief description of drawings]

1A, 1B and 1C are a plan view, a front view and a side view of an embodiment of the present invention.

2A and 2B are a plan view and a front view of a conventional objective lens driving device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Objective lens 2 Movable body 3a-3d Leaf spring for focusing 4 Relay plate 5 Leaf spring for tracking 6 Fixed part

Claims (1)

[Claims] 1. A movable body for holding an objective lens at a central portion along a track direction, four parallel leaf springs for focusing which support the movable body at four points at respective ends, and these four leaf springs. In the objective lens driving device, a focusing plate spring is connected to a fixed supporting portion through an intermediate plate at an end of the focusing plate spring opposite to the movable body. The one tracking leaf spring holding the above is arranged in parallel with the track direction and in the center of the relay plate, and both ends of the one tracking leaf spring are connected to fixed supporting portions, respectively. An objective lens driving device characterized by: