JPH06168448A - Optical disk device - Google Patents

Abstract

PURPOSE:To shorten access time by accessing with rotating operation by forming an optical pickup so as to be rotatable and forming an information region of an optical disk into a circular-arc shape which has the same center as the rotation center of the optical pickup. CONSTITUTION:An optical disk 1 has a shape in which the central part is flat and two parts of circular-arc shape are connected to both ends of the central part, and an information region 1a is provided in this part. And it is formed so that the center of the circular-arc shape part of the region 1a and the center of a rotation axis of a pickup 5 are same. A control device controls a tracking coil current so that the pickup 5 is rotated and supported to a position from which the region 1a can be irradiated with a laser beam 4. Also, when the pick up jump to the other track, the pickup is rotated by an angle in which it is positioned at a target track. Thereby, the pickup can be accessed to the target track by only rotation without parallel moving of the heavy optical pickup, and access time can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various optical disk devices capable of recording or reproducing numerical data and various data such as images.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, an optical disk device for recording / reproducing information on / from an optical disk using an optical pickup equipped with a semiconductor laser has a flat disk-shaped optical disk 12 and this optical disk 12 as shown in FIG. A motor 13 for rotating the optical disk 12 and an optical pickup 11 for generating a laser beam 14 which is translated by a linear motor (not shown) in the radial direction of the optical disk 12 shown by an arrow B in the figure.

The optical disc 12 has an information area 12a.
In the information area 12a, a recording material most suitable for each system such as a read-only type, a write-once type and a rewritable type is formed, and the access of the optical pickup 11 and the laser beam 14 are performed. Address information indicating a position on the disk necessary for tracking, drive control information necessary for driving the optical disk 12 at a predetermined speed, and the like are formed as grooves or pits.

When the optical pickup 11 records / reproduces information on / from the optical disk 12, the optical pickup 11 is held in a position where the laser beam 14 is focused on the information area 12a of the optical disk 12 which is rotationally driven by the motor 13. , You can access a track with no information or a track with necessary information.

In the conventional optical disk device, it is necessary to shorten the time required for the optical pickup 11 to access the target track, that is, the access time in order to satisfy the high speed which is a necessary condition for information processing. Has been done.

[0006]

However, in the above conventional structure, the flat optical disk 12 is used,
Since the optical pickup 11 is moved in the radial direction of the optical disc 12 using a linear motor or the like,
There is a problem in that it takes a long time to accelerate and stop the optical pickup 11 at the time of access, the access time becomes long, and accordingly, the time required for recording / reproducing information becomes long.

That is, the optical pickup 11 has a semiconductor laser, an optical system such as an objective lens, a beam splitter, a photodiode, a prism, and the like, and a drive system such as an actuator including a magnet, a coil, and a support member in a case. Since the guide bearing, the linear motor coil, and the like are provided outside the case, the total weight becomes considerably heavy, and when such a heavy optical pickup 11 is translated, it takes time to accelerate and stop. In short, the above-mentioned problems occur.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical disk device capable of further shortening the access time of an optical pickup.

[0009]

In order to achieve the above object, an optical disk device of the present invention is an optical disk device which records or reproduces information in an information area of an optical disk by using the optical pickup. The optical disk is provided so as to be rotatable in a direction perpendicular to the rotation direction of the optical disk, and the optical disk is provided with an arc-shaped information area having the same center as the rotation center of the optical pickup.

[0010]

According to the above construction, the optical pickup is rotatably formed, and the information area of the optical disk is formed in an arc shape having the same center as the rotation center of the optical pickup. -When playing back, the optical pickup will access the target track by rotation. Therefore, the access can be performed in a shorter time than the conventional configuration in which the entire weight of the heavy optical pickup is moved at the time of access.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

As shown in FIG. 1, the optical disk device of this embodiment includes a rotary shaft 2 on which an optical disk 1 described later is mounted,
A motor 3 for rotating the optical disc 1 via a rotating shaft 2.
And an optical pickup 5 for emitting a laser beam 4 for recording or reproducing information on the optical disc 1.

The optical pickup 5 is composed of an optical system and a drive system (not shown). The optical system is composed of a semiconductor laser, an objective lens, a beam splitter, a prism, a photodiode, and the like. The laser beam 4 is condensed on the surface of the optical disc 1 or the laser beam 4 and a target position on the optical disc 1 are arranged. It is designed to detect a relative positional deviation with.

On the other hand, the drive system is composed of an actuator consisting of a magnet, a coil and a supporting member, and performs focusing control for making the objective lens of the optical system follow the surface shake of the optical disk 1 and tracking control for making it follow the track shake. Thus, the relative positional relationship between the target position on the optical disc 1 and the laser beam 4 is always kept constant.

As shown in FIG. 2, the optical pickup 5 is rotatably supported on the pickup support 6 by a rotation shaft 5a passing through the center of gravity of the optical pickup 5 itself via a bearing (not shown). A coil support plate 8 having a tracking coil 7 formed on the side facing the pickup support 6 is attached to the lower part of the optical pickup 5, and a predetermined portion of the pickup support 6 facing the tracking coil 7 is attached. A tracking magnet 9 is provided in a region, specifically, a rotation region necessary for irradiating the laser beam 4 to the entire recording region 1a of the optical disc 1 described later on which the optical pickup 5 is arranged. As a result, in the optical pickup 5, the direction and strength of the current flowing through the tracking coil 7 are controlled by the control device (not shown), so that the direction of the generated magnetic field changes.
Due to the relationship between this and the tracking magnet 9, it is rotated so that light can be irradiated to a necessary portion.

On the other hand, as shown in FIG. 1, the optical disc 1 on which information is recorded / reproduced by the above optical disc device has a flat center and a curved arc shape extending from the center to the peripheral edge side. The information area 1a is provided in a region that is curved in this arc shape. And this information area 1a
The radius of the arc-shaped part of the
The laser light 4 from a is focused by the objective lens in the pickup 5 and is set to be equal to the distance for focusing.

Further, in the information area 1a, a recording material most suitable for each system such as a read-only type, a write-once type and a rewritable type is formed, and at the same time, the optical pickup 5 is accessed and the laser beam 4 is tracked. Address information indicating a position on the optical disk 1 required for the recording is formed as a groove. Drive control information and the like necessary for driving the optical disc 1 at a predetermined speed are formed in the groove as pits, and the motor 3 uses the drive control information to drive the optical disc 1 into a CAV (Constant Angular Velocit).
The rotation is performed according to the y) method or the CLV (Constant Linear Velocity) method.

The operation of the optical pickup 5 at the time of recording or reproducing with respect to the optical disc 1 which is rotated at a predetermined speed in the above structure will be described. At the time of recording / reproducing information, first, the control device rotates the optical pickup 5 to a position where the laser beam 4 can be irradiated to the information area 1a where the recording / reproducing of information should be performed, and the tracking coil 7 is held. Control the current flowing through. As a result, the optical pickup 5 is rotated to a predetermined position, emits the laser beam 4 to the information area 1a where information is to be recorded / reproduced, and the drive system provided in the optical pickup 5 focuses the information on the information. Record / playback. Then, when it becomes necessary to jump to another track, the control device causes the optical pickup 5 to be rotated to a position where the track to be jumped can be irradiated with the laser beam 4 and to flow to the tracking coil 7 so as to be held. Control the current. This is the optical pickup 5
In the focused state, rotates to an angle at which the target track can be tracked and records / reproduces information again.

As described above, in the optical disk device of the present embodiment, the optical pickup 5 is rotatably formed, and the information area 1a of the optical disk 1 on which information is recorded / reproduced by the optical pickup 5 is an optical disk. Since it is formed in an arc shape having the same center as the rotation center of the pickup 5, it is possible to access the target track only by rotating it without rotating the heavy optical pickup in parallel as in the conventional case. Will be accessible at.

The optical disk device of the present invention is not limited to the above-mentioned structure, and as shown in FIG.
The driving force of the stepping motor 10 may be directly transmitted to the rotating shaft 5a of the optical pickup 5'or via a reduction gear. By using the stepping motor 10, the rotation angle of the optical pickup 5'can be easily controlled.

[0021]

As described above, in the optical disk device of the present invention, the optical pickup is provided rotatably in the direction perpendicular to the rotation direction of the optical disk, and the optical disk has the same center as the rotation center of the optical pickup. This is a configuration including an arc-shaped information area.

Therefore, at the time of recording or reproducing, the access to the target track of the optical pickup is performed not by the parallel movement as in the prior art but by the rotation, so that the access can be performed in a shorter time. Play.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical disc device according to an embodiment of the present invention.

FIG. 2A is a front view of the vicinity of an optical pickup in the optical disk device, and FIG. 2B is a vertical cross-sectional view of a main portion near the pickup.

FIG. 3A is a front view of the vicinity of a pickup in an optical disk device according to another embodiment of the present invention, and FIG. 3B is a side view of the vicinity of the pickup.

FIG. 4 is a configuration diagram of a conventional optical disc device.

[Explanation of symbols]

 1 Optical Disc 1a Information Area 2 Rotation Axis 3 Motor 4 Laser Light 5 Optical Pickup 5'Optical Pickup 5a Rotation Axis 5a 'Rotation Axis 6 Pickup Support 7 Tracking Coil 8 Coil Support 9 Tracking Magnet 10 Stepping Motor

Claims (1)

[Claims] 1. An optical disc apparatus for recording or reproducing information in an information area of an optical disc by using the optical pickup, wherein the optical pickup is provided rotatably in a direction perpendicular to a rotation direction of the optical disc, An optical disk device comprising an arc-shaped information area having the same center as the rotation center of an optical pickup.