JPH08124197A - Optical disk driving device - Google Patents

Abstract

PURPOSE: To perform tracking control at high speed by turning an optical unit by a minute angle and performing the tracking control. CONSTITUTION: An actuator 25 constituted of the optical unit 21, a focus coil 22, an optical axis adjustment coil 23 and a tracking coil 24 is pivotally born freely turnably in the directions of a track and optical axis adjustment, and is turned in respective directions by a minute angle. Together with that, a reflection mirror 26 reflecting outgoing light from the optical unit 21 between an optical disk surface and the optical unit 21 is formed in a circular arc shape in the radial direction of the optical disk and inclined by a prescribed angle to the optical disk surface. Thus, since the tracking control is performed by turning the optical unit 21 by a minute angle, the tracking control is ended at high speed. Further, since two systems of control of conventional tracking coil and thread motor are reduced to one system of turning control of an actuator, power consumption and heat generation are reduced.

Description

Detailed Description of the Invention

[0001]

[Industrial application] In recent years, it has become possible to process a large amount of data at high speed due to technological innovation of computers. As an example of a large-capacity storage medium that meets this requirement, C
D-ROM is used. The present invention provides such C
The present invention relates to an optical disc drive device capable of accessing a D-ROM at high speed.

[0002]

2. Description of the Related Art A conventional optical disk drive device will be described with reference to the drawings. FIG. 3 is a block diagram of a conventional optical disk drive device. In the figure, 1 is an optical unit for reading data from an optical disc, 2 is a focus coil for moving the optical unit 1 in the focus direction, and 3 is a tracking coil for moving the optical unit 1 in the track direction (radial direction of the disc).

Reference numeral 4 is a sled motor for driving the entire unit including the optical unit 1, focus coil 2 and tracking coil 3 in the track direction, and 5 is a spindle motor for rotating an optical disk.

Reference numeral 6 is a spindle servo circuit for controlling the spindle motor 5 at a predetermined rotation speed, 7 is a focus servo circuit for controlling the focus coil 2 at a predetermined driving force,
Reference numeral 8 is a tracking servo circuit for controlling the tracking coil 3 to a predetermined driving force, 9 is a sled servo circuit for controlling the sled motor 4, 10 is an optical disk drive circuit, and the spindle servo circuit 6 and the focus servo circuit 7 described above. It controls each servo circuit of the tracking servo circuit 8 and the sled servo circuit 9 and also controls the operation of the entire optical disk device.

The operation of the conventional optical disk drive device configured as described above will be described. The focus servo circuit 7 drives the focus coil 2 so that the reflection signal of the optical disc obtained from the optical unit 1 is in a focused state and focuses.

Similarly, the tracking servo circuit 8 drives the tracking coil 3 so that the optical unit 1 traces the optimum track position and traces the track. Further, the spindle servo circuit 6 rotationally drives the spindle motor 5 and controls the rotation speed based on the reflection signal of the optical disc obtained from the optical unit 1 so that the linear velocity becomes constant regardless of the position of the track.

The sled motor 4 is used when the amount of movement in the track direction exceeds the amount of control by the tracking coil 3, and tracking control is performed by the sled servo circuit 9. The optical disk drive circuit 10 controls the overall optical disk drive device by adjusting the gain of each servo system as described above.

The optical disc drive apparatus controlled as described above performs two types of tracking control according to the medium reading method. One of them is a track jump, and the other one is a long jump.

The track jump performs tracking control between adjacent tracks by controlling only the tracking coil 3 as in the case of reproducing a music CD. The number of tracks to jump is several hundred tracks, and the required time is linear velocity. Even if the number of jump tracks exceeds a certain control, it is completed in several tens of ms.

On the other hand, the long jump is to perform tracking control between distant tracks by control using the tracking coil 3 and the sled motor 4, as in the case of searching a CD-ROM, and rough seek control by the sled motor 4. After performing, the error of several 100 tracks due to the rough seek control is performed by performing the fine seek control by the tracking coil 3 several times. The required time is several 100 ms depending on the mass of the optical unit and the torque of the sled motor 4.

[0011]

As described above, when a CD-ROM is used as an external storage device of a computer, it is important to shorten the tracking control time in order to perform a high speed search. Since it is necessary to control the dense seek, it is difficult to shorten the access time, and when the torque of the sled motor is increased, the mass of the optical unit is increased and the power consumption is increased.

It is an object of the present invention to provide an optical disk drive device capable of high speed tracking control.

[0013]

In order to solve the above problems, the present invention provides an actuator composed of an optical unit, a focus coil, an optical axis adjusting coil, and a tracking coil in a track direction (with respect to an optical disk surface). It is rotatably supported in the optical axis adjustment direction (vertical surface with respect to the optical disk surface) and rotated by a small angle in each direction, and the light emitted from the optical unit is used as the optical disk surface. A reflecting mirror that reflects light from the optical unit is arranged in an arc shape in the radial direction of the optical disc and is inclined at a required angle with respect to the surface of the optical disc.

[0014]

With the above structure, the tracking control is performed by rotating the optical unit by a slight angle, so that the tracking control can be completed at a higher speed. Further, since the control of the two systems of the tracking coil and the sled motor is controlled by one system of the rotation control of the actuator, it is possible to reduce the power consumption and the heat generation especially regarding the sled motor.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical disk drive device according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an optical disk drive device according to an embodiment of the present invention. FIG.
In the figure, 21 is an optical unit for reading the data of the optical disc, 22 is a focus coil for driving the optical unit 21 in the focus adjustment direction, and 23 is the optical unit 21.
Optical axis adjustment coil for aligning the optical axis of the optical axis with the vertical line of the optical disk, 24 is a tracking coil for driving the optical unit 21 in the track direction, 25 is an actuator, and the optical unit 21, focus coil 22, optical axis adjustment It is composed of a coil 23 and a tracking coil 24, and is rotatably supported in a track direction (a rotation surface parallel to the optical disk surface) and an optical axis adjusting direction (a rotation surface vertical to the optical disk surface). ing.

Reference numeral 26 is a reflecting mirror, which is arranged in an arc shape in the radial direction of the optical disk and is inclined at an angle of about 45 degrees with respect to the optical disk surface.

Reference numeral 27 is a spindle motor for rotating the optical disc, 31 is a spindle motor 27 controlled to a predetermined rotation speed, and the linear velocity is constant irrespective of the position of the track based on the reflection signal of the optical disc obtained from the optical unit 21. The spindle servo circuit controls the rotation speed so that Reference numeral 32 is a focus servo circuit that controls the focus coil 22 to a required driving force, and 33 is an optical axis adjustment that controls the optical axis adjustment coil 23 to a required driving force to match the optical axis of the optical unit 21 with the vertical line of the optical disc. A servo circuit 34 is a tracking servo circuit which controls the tracking coil 24 to a required driving force to drive the optical unit 21 in a predetermined track direction. An optical disk drive circuit 35 includes a spindle servo circuit 31, a focus servo circuit 32, an optical axis adjustment servo circuit 33, and
It controls each servo circuit of the tracking servo circuit 34 and also demodulates data and signals to control the operation of the entire optical disk device.

FIG. 2 is a view for explaining the positional relationship between the actuator 25 and the reflecting mirror 26 in FIG. In the figure, the actuator 25 is rotatably supported about the tracking control shaft 36 in the track direction on a surface parallel to the optical disk surface. On the other hand, with respect to the adjustment direction of the optical axis of the actuator 25, the actuator 25 is rotatably supported around the optical axis adjustment shaft 37 and on the surface perpendicular to the optical disk surface.

In the embodiment of the present invention, as described above, the example in which the tracking control shaft 36 and the optical axis adjusting shaft 37 are pivotally supported is shown. However, a rotating shaft using a ball bearing or the like is used. It may be configured so as to be rotatably supported in all directions without being restricted by.

Further, the reflecting mirror 26 is formed in an arc shape centered on the tracking control shaft 36, and its reflecting surface is arranged so as to form an angle of 45 degrees with the optical disk surface.
In one embodiment of the present invention, the reflection surface is 45 degrees,
Although the tracking control shaft 36 is vertical (the rotating surface of the actuator 25 is parallel to the optical disk surface), the arrangement of the reflecting surface is not necessarily limited to 45 degrees depending on the arrangement of the tracking control shaft 36 and the actuator 25.

The operation of the optical disk drive device of the present invention constructed as above will be described. In FIG. 1, the focus servo circuit 32 drives the focus coil 22 based on the reflection signal from the optical disk surface obtained from the optical unit 21 to perform focus control. The tracking servo circuit 34 is similar to the optical unit 21.
The tracking coil 24 is driven on the basis of the reflection signal from the optical disk surface obtained from (1) to trace the track. Further, similarly, the spindle servo circuit 31 drives the spindle motor 27 based on the reflection signal from the optical disc surface obtained from the optical unit 21, and rotates the optical disc so that the linear velocity becomes constant.

Further, the optical axis adjusting servo circuit 33 drives the optical axis adjusting coil 23 based on the reflection signal from the optical disk surface obtained from the optical unit 21, and aligns the optical axis. The optical disk drive circuit 35 controls the gain of each servo system as described above and controls the entire optical disk drive device.

In FIG. 2, the laser light output from the optical unit 21 of the actuator 25 is incident on the reflecting mirror 26 while being focused, and is further reflected to irradiate the surface of the optical disk vertically. The laser light reflected on the surface of the optical disc follows the optical path opposite to that when it is incident, and is focused on the light receiving element in the optical unit 21.

The focus control is similar to the conventional control. On the other hand, the tracking control is performed by controlling the rotation angle of the actuator 25. That is, when the actuator 25 is rotated by a certain minute angle, the laser light emitted from the optical unit 21 has an arc whose center is the tracking control axis 36 and whose radius is the distance between the reflection mirror 26 and the tracking control axis 36. 26 and incident on the optical disc. Thus, the rotation of the actuator 25 is expanded into an arc of sufficient length.

Therefore, as compared with the conventional tracking control, the control relating to the sled motor can be reduced, and the tracking control is performed by rotating the actuator 25 by a slight angle without moving it. As a result, since the actuator 25 having a small inertia has only to be rotated by a small angle, the tracking control can be completed at a higher speed. Moreover, since a component having a large mass is not moved, power consumption and heat generation can be reduced.

[0026]

According to the present invention, since the tracking control is performed by rotating the optical unit by a slight angle, the tracking control can be completed at a higher speed. Also,
Since the number of thread motors is reduced, it is possible to reduce power consumption and heat generation particularly related to the thread motor.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a positional relationship between an actuator and a reflecting mirror in FIG.

FIG. 3 is a block diagram of a conventional optical disk drive device.

[Description of symbols] 1 optical unit 2 focus coil 3 tracking coil 4 thread motor 5 spindle motor 6 spindle servo circuit 7 focus servo circuit 8 tracking servo circuit 9 thread servo circuit 10 optical disk drive circuit 21 optical unit 22 focus coil 23 optical axis adjustment Coil 24 Tracking coil 25 Actuator 26 Reflector 27 Spindle motor 31 Spindle servo circuit 32 Focus servo circuit 33 Optical axis adjustment servo circuit 34 Tracking servo circuit 35 Optical disk drive circuit 36 Tracking control axis 37 Optical axis adjustment axis

Claims (3)

[Claims] 1. An optical unit, a focus coil, and
An actuator having a tracking coil is rotatably supported in the radial direction of the optical disk surface in parallel with the surface of the optical disk, and is rotated by a slight angle in the radial direction. An optical disk drive device, wherein a reflecting mirror for reflecting between a surface and the optical unit is arranged in an arc shape in a radial direction of the optical disk and inclined at a required angle with respect to the surface of the optical disk. 2. The optical disk drive device according to claim 1, wherein the center of the arc of the reflecting mirror coincides with the center of the tracking control shaft that rotates the actuator. 3. The rotating surface of the actuator is parallel to the surface of the optical disk, and the reflecting mirror is arranged so as to be inclined at an angle of 45 degrees with respect to the surface of the optical disk. 1. The optical disk drive device described in 1.