JPH0677329B2 - Optical recording / reproducing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording / reproducing apparatus for optically recording / reproducing information on / from a disc-shaped recording medium.

2. Description of the Related Art An optical recording / reproducing apparatus uses an objective lens with respect to the surface of a disk-shaped recording medium in order to correct focus deviation and tracking deviation due to eccentricity due to vertical movement of the disk-shaped recording medium such as a magneto-optical disk. An objective lens driving device that drives in two axes of a vertical optical axis direction (hereinafter referred to as a focus direction F) and a substantially radial direction parallel to the disc-shaped recording medium surface (hereinafter referred to as a tracking direction T); An optical head composed of an optical block for making a light beam incident on the objective lens is moved along the substantially radial direction of the disc-shaped recording medium to optically record and reproduce information on the disc-shaped recording medium.

A conventional optical recording / reproducing apparatus of this type is constructed as shown in FIGS.

That is, the driving in the focus direction F is performed by moving the focusing coil 4 in the air gap of the magnetic circuit composed of the magnet 6a and the magnetic yoke 7a in which the movable portion composed of the objective lens 1 and the lens holder 2 is provided on the base 8. By the electric type converter,
It is obtained by translational movement via the spring members 3a to 3d. The driving in the tracking direction T is an electrodynamic type in which the tracking coil 5 is arranged in the air gap of the magnetic circuit composed of the magnet 6a and the magnetic yoke 7a provided on the base 8 with the movable portion composed of the objective lens 1 and the lens holder 2. Depending on the converter, spring material 3a
Obtained by translating through ~ 3d.

At this time, as shown in FIG. 2B, the objective lens driving device is
An optical block 9 for making a light beam incident on the objective lens 1 is attached to a swing arm 10, and an optical head including the objective lens driving device and the optical block 9 is attached to a magnetic circuit including a magnet 6b and a magnetic yoke 7b. By the electrokinetic converter in which the access coil 11 attached to the swing arm 10 is disposed in the space of the swing arm 10, the access direction Ad (the same as the tracking direction T on the recording medium is centered on the bearing portion 12 of the swing arm 10). Direction) is driving access. In addition, 13 is a fixed part.

Problems to be Solved by the Invention However, an objective lens driving device is an electrodynamic converter in which a movable coil including an objective lens and a lens holder is provided with a driving coil in an air gap of a magnetic circuit including a magnet and a magnetic yoke. Since the drive in the focus direction F and the tracking direction T is obtained, when the entire objective lens driving device is driven to access in the access direction Ad (the same direction as the tracking direction T) on the recording medium by the swing arm together with the optical block, Since the magnetic circuit of the objective lens driving device occupies a large proportion of the moving part mass, it is difficult to shorten the access time.

Therefore, the present invention provides an optical recording / reproducing apparatus capable of reducing the mass of the entire objective lens driving device and shortening the access time.

Means for Solving the Problems In order to solve the above problems, according to the present invention, an optical head including a magnet and a magnetic yoke for accessing and driving an optical head including the entire objective lens driving device and an optical block by a swing arm. The magnetic circuit for driving and the magnetic circuit for driving the movable portion including the objective lens and the lens holder of the objective lens driving device in the focus direction F and the tracking direction T are integrated.

Action The present invention provides a magnetic circuit for driving the movable part of the objective lens driving device, which includes the objective lens and the lens holder, in the focus direction F and the tracking direction T, and for driving the optical head in the access direction Ad on the recording medium. By integrating with the magnetic circuit for driving the optical head, the mass of the entire objective lens driving device can be reduced and the access time of the optical head can be shortened.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a front view showing the overall construction of an optical recording / reproducing apparatus according to an embodiment of the present invention, and FIG. 1B is a plan view thereof.

In FIG. 1, the objective lens driving device is the objective lens 1
An optical block for recording / reproducing information on / from a recording medium, in which a movable portion including a lens holder 2 has optical elements (not shown) such as a semiconductor laser, a half mirror, and a collimating lens via spring materials 3a to 3d. By a conductive type converter attached to a part of 9 and having the focusing coil 4 and the tracking coil 5 arranged in the surface magnetic field generated by the magnet 6c, by performing translational movements in the focusing direction F and the tracking direction T, respectively. Get its drive.

An optical head including the entire objective lens driving device and the optical block 9 is fixed on one end of the swing arm 10, and an access coil 11 also attached to the swing arm 10 includes a magnet 6c and a magnetic yoke 7c. By the conductivity type converter placed in the air gap of the magnetic circuit,
Access is driven in the access direction Ad around 12.

In the optical recording / reproducing apparatus of the present embodiment configured as described above, the magnetic circuit for driving the movable part of the objective lens driving device and the magnetic circuit for driving the entire optical head are integrally formed. Since it is not necessary to provide a magnetic circuit as the objective lens driving device, the magnetic circuit and the base, which occupy a large proportion of the total mass of the objective lens driving device, are eliminated, and the mass of the entire optical head can be reduced. Can be shortened.

Furthermore, since the number of expensive magnets, magnetic yokes, and bases can be reduced, a cheaper optical recording / reproducing apparatus can be achieved.

Further, it goes without saying that if the optical block 9 and the swing arm 10 are integrated, the number of parts can be reduced, the cost can be reduced, and the assembly can be facilitated. Further, if the center of gravity of the entire movable portion integrated with the swing arm and the center of rotation of the swing arm are made to coincide with each other, the optical recording / reproducing apparatus as a whole can be configured to be strong against external disturbance such as impact force. .

According to the present invention, the focusing coil and the tracking coil are arranged in the air gap of the magnetic circuit including the magnet and the magnetic yoke via the spring member in the movable portion including the objective lens and the lens holder of the objective lens driving device. The drive is obtained by translational movements in the focus direction F and the tracking direction T by the conductive type converter described above, and an optical head including the entire objective lens driving device and an optical block is fixed to one end of the swing arm. Similarly, the access coil mounted on the swing arm is placed in the air gap of the magnetic circuit consisting of the magnet and the magnetic yoke, and the access direction is centered on the bearing.
In an optical recording / reproducing apparatus of a type that accesses and drives Ad, a magnetic circuit that drives a movable part of an objective lens driving device in a focus direction F and a tracking direction T, and an optical head that drives access in an access direction Ad on a recording medium. Therefore, the mass of the entire objective lens driving device can be reduced by integrating with a magnetic circuit for the purpose, the access time of the optical head can be shortened, and an inexpensive optical recording / reproducing device can be realized.

[Brief description of drawings]

FIG. 1A is a front view showing the overall configuration of an optical recording / reproducing apparatus according to an embodiment of the present invention, FIG. 1B is a plan view of the same, and FIG. 2A is an overall configuration of a conventional optical recording / reproducing apparatus. The front view shown and FIG. 2B are plan views of the same. 1 ... Objective lens, 2 ... Lens holder, 3a-3d ... Spring material, 4 ... Focus coil, 5 ... Tracking coil, 6a-6c ... Magnet, 7a-7c ... Magnetic yoke, 8
...... Base, 9 ...... Optical block, 10 ...... Swing arm, 11 ...... Access coil, 12 ...... Bearing part, 13 ...... Fixed part.

Claims (2)

[Claims] 1. An objective lens of an apparatus for optically recording / reproducing information on / from a disc-shaped recording medium is provided in a substantially radial direction parallel to the disc-shaped recording medium surface and on the disc-shaped recording medium surface. An optical axis having a mechanism for driving in a direction perpendicular to the optical axis, and a magnet for driving the movable portion including the objective lens and a lens holder holding the objective lens in the optical axis direction and a magnetic yoke. An objective lens driving device including a directional magnetic circuit, a radial magnetic circuit including a magnet for driving the movable portion in the substantially radial direction and a magnetic yoke, and for making a light beam incident on the objective lens. An optical head including the optical block of FIG. 1 is mounted on a substantially end face in the longitudinal direction of the swing arm, the swing arm has a support point at a substantially central portion in the longitudinal direction, and the objective lens is arranged in the substantially radial direction of the recording medium. An optical head driving mechanism attached to the swing arm for driving the optical head in the substantially radial direction, having a mechanism for driving the optical head around the support point so as to be movable along Of a swing arm device including a coil, a magnetic circuit for driving an optical head, which includes a magnet attached to a fixed portion and a magnetic yoke, the magnetic circuit for driving the optical head is used for the optical axis direction of the objective lens driving device. An optical recording / reproducing apparatus characterized by being integrated with a magnetic circuit or the magnetic circuit for substantially radial direction. 2. An optical head for recording and reproducing information on a recording medium, comprising an objective lens driving device and optical elements such as a semiconductor laser, a half mirror, and a collimating lens, is constructed in or on an arm of a swing arm. An optical block to which the optical element is attached and the swing arm are integrated, and a center of gravity of all movable parts including the optical head and the swing arm is substantially aligned with a rotation center of the swing arm. The optical recording / reproducing apparatus according to claim 1.