JPH0237531A - Optical head supporting device - Google Patents

Abstract

PURPOSE:To obtain a device miniaturize and with a large movable range by supporting a movable coil on which an optical head is fixed via two kinds of elastic members having different spring rigidity. CONSTITUTION:Plate springs 201 and 202 of U-shape are fixed on the both ends of the movable coil 101 on which the optical head 103 is fixed. And the springs 201 and 202 are supported by locating plate springs 203 and 204 whose plate thickness is decreased then that of the springs 201 and 202 and whose rigidity is decreased in parallel between the longitudinal parts 201A, 201B and 202A, 202B of the springs 201 and 202, and the other ends, are fixed on the fixing parts 102A and 102B of a magnetic circuit 102. By employing such consti tution, the displacement of the plate spring in a longitudinal direction can be off-set when the head 103 is moved in the radius direction of a fixed disk 104 and the elastic deformation of the springs (201-204) are generated since the plate thickness of the springs 203 and 204 are formed thinner than that of the springs 201 and 202, and they are slided almost linearly even when the coil 101 is displaced by large distance. Therefore, it is possible to obtain the device miniaturized and with the large movable range.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical head support device for an optical disc device that optically records or reproduces information on a recording medium.

BACKGROUND OF THE INVENTION In recent years, in optical disk devices that record information on or reproduce information from a recording medium at extremely high density, an optical head support mechanism is used to
The optical head accesses the trunk formed on the recording medium with extremely high precision to control tracking.

An example of the above-mentioned conventional optical head support mechanism (Japanese Unexamined Patent Publication No. 61-42742) will be described below with reference to the drawings.

FIG. 3 shows a conventional optical head support mechanism. In FIG. 3, reference numeral 36 denotes a temporary spring, which supports the movable shaft 34 of the voice coil motor 6 so as to be movable in the radial direction of the disk 104, and supports the fixed part 37 of the voice coil motor 6.
It is fixed to .

101 is a movable coil fixed to the movable shaft 34. 31 is a reflecting mirror, and fixed optical systems 12 to 2
A light beam emitted from an angle of 0.32 mm is made incident on the objective lens 7 and irradiated onto the optical disc l. The objective lens 7 is
It is fixed to the movable shaft 34 via an automatic focusing mechanism 8.

Regarding the optical head support mechanism configured as above,
The operation will be explained below.

By applying a driving current to the movable coil 101, the plate spring 36 is deformed as shown in FIG.
1 and the objective lens 7 are moved. Thereby, the light beams emitted from the fixed optical systems 12 to 20.32 are accessed in the radial direction of the disk 101, and track control is performed on the tracks on the disk 101.

Problems to be Solved by the Invention However, in the above configuration, the plate spring 36 is symmetrical with respect to the moving direction and directly supports the movable shaft 34, so that the movable range of the movable shaft 34 is limited. When the leaf spring 36 is large, the length in the longitudinal direction of the leaf spring 36 becomes long, and the optical head support l1 mechanism becomes large.The present invention aims to solve the above problem.
The present invention provides an optical head support mechanism that is small but has a large movable range.

Means for Solving the Problems In order to solve the above-mentioned problems, the optical head support mechanism of the present invention provides optical means for performing automatic focus adjustment on the surface of an optical disc to form a light beam spot and reproducing, recording, or erasing information. a voice coil motor having a moving coil to which the optical means is fixed and driving the optical means in a radial direction of the optical disk; a first elastic member and a second elastic member supporting the moving coil; The second elastic member supports the movable coil via the first elastic member, and the first elastic member and the second elastic member support the sliding of the movable coil. The first elastic member and the second elastic member are arranged only on one side with respect to the moving direction, and have different spring rigidities.

Effects The present invention, with the above-described configuration, can increase the movable range of the movable coil without increasing the length in the longitudinal direction of the first elastic member and the second elastic member that bias the movable coil. becomes.

Example Below, regarding an optical head support device according to an example of the present invention,
This will be explained with reference to the drawings.

FIG. 1 shows a schematic diagram of an optical head support device in an embodiment of the present invention. A movable coil 101 is located in the gap of the magnetic circuit 102, fixes the optical head 103, and moves in the radial direction of the disk 104.

201 and 202 are U-shaped first leaf springs;
The magnetic circuits 102 are arranged in parallel facing each other.
The optical head 103 and the movable coil 101 are sandwiched between the optical head 103 and the moving coil 101.
Supports approximately the center of gravity of a movable body with 203°20
4 is a second leaf spring, which is the same as the first leaf spring 201.
202, each longitudinal portion 201A.

201B, 202A, and 202B in parallel with each other, respectively. , 202.

The second leaf springs 203 and 204 have their other ends fixed to the fixed parts 102A and 102B of the magnetic circuit 102, and the fixed parts 102A and 102B are connected to the first leaf springs 201 and 2.
02 respective longitudinal parts 201A, 201B, 202A
, 202B. Further, the second leaf spring 203204 has a shorter length in the longitudinal direction than the first leaf spring 201, 202, but the plate thickness is made smaller and the spring rigidity of the disk 104 in the radial direction is made smaller.

The first leaf springs 201 and 202 and the second leaf spring 2
03 and 204 are both provided on only one side with respect to the moving direction of the movable body, and support the movable body so as to be movable in the radial direction of the disk 104.

Regarding the optical head support device configured as above,
The operation will be explained below using FIGS. 2 and 3. 2 and 3 are schematic views when the optical head 103 is moved in the radial direction of the disk 104, and the broken line indicates the first leaf spring 201.2 when the optical head 103 is not moved.
02 and the second leaf springs 203 and 204 are shown.

The movable coil 101 to which the optical head 103 is fixed
By applying a driving current to the disk 104, the disk 104 is moved in the radial direction, and a predetermined track on the disk 103 is accessed to perform tracking control. leaf spring 2
03.204 is elastically deformed in the radial direction of the disk 104 as shown in FIGS. 2 and 3. At this time, with respect to the longitudinal direction of the temporary spring, the second leaf spring 203°204
In, the fixed portions 102A, 10 of the magnetic circuit 102
Free end 201A when viewed from 2B.

202A is displaced by 1 in the direction of the movable body. Furthermore, in the first leaf springs 201 and 202, the fixed ends 201B and 202B of the movable coil 101 are connected to the second leaf springs 203 and 2 when viewed from the free ends 201A and 202A.
It is displaced by m in the direction opposite to the deformation direction of 04. Therefore, the length in the longitudinal direction of the second leaf springs 203 and 204 is smaller than the length in the longitudinal direction of the first leaf springs 201 and 202; By making the thickness smaller than the thickness of the first leaf springs 201, 202 by an appropriate proportion, the first leaf springs 201, 202 are thinner than the first leaf springs 201, 202.
202 and the second leaf springs 203 and 204, and even when the movable body is largely displaced, the movable body is not affected by the longitudinal displacement of the temporary spring. slides almost linearly.

As described above, according to this embodiment, the U-shaped first
The leaf springs 201 and 202 support the movable body from one side of the moving axis with the magnetic circuit 102 therebetween, and the second leaf springs 203 and 204 adjust the spring rigidity of the disc 104 in the radial direction. By making the spring rigidity appropriately smaller than that of the first leaf spring 201, 202, the length in the longitudinal direction of the first leaf spring 201, 202 and the second leaf spring 203, 204 can be reduced, and the movable body can travel a wide range of distances in a straight line.

Effects of the Invention As described above, the present invention provides an optical means for performing automatic focus adjustment on an optical disk surface to form a light beam spot to reproduce, record, or erase information, and a movable coil to which the optical means is fixed. a voice coil motor that drives the optical means in the radial direction of the optical disk, a first elastic member and a second elastic member that support the movable coil, and the second elastic member supports the movable coil via the first elastic member, the first elastic member and the second elastic member are arranged only on one side with respect to the sliding direction of the movable coil, and Since the first elastic member and the second elastic member have different spring stiffnesses, the range of movement of the optical head can be increased even though the optical head is small.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an optical head support mechanism according to an embodiment of the present invention, FIGS. 2 and 3 are schematic diagrams of the optical head when the optical head is moved in the radial direction of the disk, and FIG. FIG. 5 is a schematic view of an optical head support mechanism in a conventional example of the invention, and FIG. 5 is a modified view of the leaf spring in FIG. 101... Moving coil, 102... Magnetic circuit, 103... Optical head, 104...
...Disc, 201 202...First leaf spring, 203.204...Second leaf spring. Name of agent: Patent attorney Masataka Awano (1 person)

Claims (1)

[Claims] It has an optical means that performs automatic focus adjustment to form a light beam spot on the surface of the optical disc and reproduces, records, or erases information, and a movable coil to which the optical means is fixed, and the optical means is attached to the optical disc. a voice coil motor that drives in the radial direction of the movable coil; a first elastic member and a second elastic member that support the movable coil; The first elastic member and the second elastic member support the movable coil, and
Placed only on one side with respect to the moving direction of the moving coil,
In the optical head support device, the first elastic member and the second elastic member have different spring stiffnesses.