JPH0581729A - Optical recording / reproducing device - Google Patents

Abstract

(57) [Summary] [Object] To provide an optical recording / reproducing apparatus which prevents the magnetic head from contacting the optical disk and damaging the magnetic head or the optical disk due to surface wobbling of the optical disk. An optical head 2 for projecting light onto an optical disc for recording data to record and reproduce the data and outputting a surface wobbling signal of the optical disc, a magnetic head 6 used for recording data on the optical disc, and this magnetic head. 6, an actuator 7 for changing the absolute height position of the magnetic head 6, a position sensor 15 for detecting the absolute height position of the magnetic head 6, and an actuator by inputting a surface shake signal from the optical head 2 and a detection signal from the position sensor 15. And a control means 17 for controlling the absolute height position of the magnetic head 6 by outputting a signal to the magnetic head 7. [Effects] The distance between the magnetic head and the optical disk can be kept constant, and the above object can be achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording / reproducing device such as a magneto-optical disk device.

[0002]

2. Description of the Related Art As a conventional optical recording / reproducing apparatus, for example, there is a magnetic field modulating magneto-optical disk apparatus described in Japanese Patent Laid-Open No. 63-217548. This conventional magneto-optical disk device adopts a method in which the magnetic head floats on the disk surface by the wind pressure generated on the disk surface, like the magnetic head used in a hard disk (non-exchange type large capacity disk). ing. In such a magneto-optical disk device, even if the disk has a little surface wobbling, the flying height of the magnetic head increases or decreases due to changes in the wind pressure generated on the surface, and It is designed to follow the proximity part.

[0003]

However, in such a conventional optical recording / reproducing apparatus, when the surface deviation of the disk is larger than the flying height of the magnetic head on the disk surface, the magnetic head moves on the disk surface. There is a risk of contact, and when the magnetic head contacts the disk surface in this way,
There is a problem that the magnetic head and the disk are damaged and the device becomes inoperable. Then, this invention makes it a subject to solve the above problems.

[0004]

In order to solve the above problems, the present invention provides an optical disc for recording data, and an optical system for projecting light on the optical disc to record and reproduce the data and to output a surface wobbling signal of the optical disc. A head, a magnetic head used when recording data on the optical disc and arranged on the opposite side of the optical head from the optical disc, an actuator for changing the absolute height position of the magnetic head, and an absolute height of the magnetic head. A position sensor for detecting a position; and a control means for controlling a height position of the magnetic head by inputting a surface wobbling signal from the optical head and a detection signal from the position sensor and outputting a signal to the actuator. Is provided.

[0005]

According to the optical recording / reproducing apparatus having such a structure, the control means inputs the surface wobbling signal from the optical head and the detection signal of the absolute height position of the magnetic head from the position sensor, and controls the magnetic head. The height position of the magnetic head is controlled by outputting a signal to an actuator that changes the absolute height position of the magnetic head. By controlling in this way, the distance between the magnetic head and the optical disk can be kept substantially constant, and even when the surface wobbling of the optical disk is large, it is possible to reliably prevent the magnetic head from contacting the surface of the optical disk. It is possible to prevent damage to the magnetic head and the optical disc.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views showing an embodiment of an optical recording / reproducing apparatus according to the present invention. In FIG. 1, reference numeral 1
Is an optical disc, and an optical head 2 is arranged below the optical disc 1. The optical head 2 is fixed to the lower part of a substantially U-shaped carriage 4, and the optical disk 1
It has an objective lens 3 for projecting the light L. A magnetic head 6 used for recording data on the optical disc 1 is arranged above the optical disc 1, and the magnetic head 6 is moved up and down in the height direction by an actuator 7 to move to an absolute height position (from a fixed stationary portion). Height position) can be changed. The carriage 4 moves in the radial direction of the optical disc 1 as the optical disc 1 rotates, and during this period, the optical head 2 and the magnetic head 6 record or reproduce data on the optical disc 1. Reflection mirrors 10 and 11 for bending the light B in a right angle direction are provided at the lower right portion of the carriage 4 and an intermediate portion above the height thereof, and a position sensor 15 is provided at the upper right portion of the carriage 4. There is. A reflection mirror 12 is also provided on the right side of the magnetic head 6 in the drawing, while a light source 8 for emitting light B is provided on the right end of the optical head 2 in the drawing. Light B emitted from the light source 8
Are successively reflected by the reflection mirrors 10, 11, 12 and finally enter the position sensor 15. Therefore, when the absolute height position of the magnetic head 6 changes, the incident position of the light B on the position sensor 15 changes in the arrow direction, and the position sensor 15 can detect the absolute height position of the magnetic head 6. .

Since the optical head 2 focuses the light L projected from the objective lens 3 onto the optical disc 1 to record or reproduce data, when the surface wobbling occurs due to the rotation of the optical disc 1, the focus is focused. In order to prevent the damage of the objective lens 3, the focus control for moving and adjusting the objective lens 3 in the optical axis direction is performed by an actuator (not shown) operated by a signal from a focus control circuit (not shown). Therefore, the signal output from the focus control circuit to the actuator can also be used as a surface wobbling signal of the optical disk 1, and this surface wobbling signal indicates the operation of the entire apparatus from the optical head 2 as shown in FIG. It is input to the control circuit 17 for controlling. In addition to this, a detection signal corresponding to the absolute height position of the magnetic head 6 detected by the position sensor 15 is input to the control circuit 17 from the position sensor 15.
The control circuit 17 controls the absolute height position of the magnetic head 6 by outputting a signal to the actuator 7 based on the surface shake signal from the optical head 2 and the detection signal from the position sensor 15. ing.

FIG. 3 is a flow chart showing the operation procedure of the above embodiment, and the operation will be described along with this. Although this flow chart shows the case of recording data on the optical disc 1, the following work is performed as the preparatory work. That is, the magnetic head 6 is connected to the optical disc 1
The magnetic head 6 is levitated from the optical disk 1 by a certain distance (for example, 50 μm) from the optical disc 1 so that the magnetic head 6 does not break. After that, the optical disk 1 is started to rotate to start the recording operation, and recording pits for recording data are formed in the recording film of the optical disk 1 by the light from the optical head 2 and the external magnetic field from the magnetic head 6.

During recording of such data, the position sensor 15 detects and controls the absolute height position of the magnetic head 6 by the incident position of the reflected light of the light B emitted from the light source 8 as described above. The detection signal is input to the circuit 17, and the optical head 2 inputs the surface wobbling signal of the optical disk 1 to the control circuit 17 as described above. For example, assuming that the optical disk 1 is wobbling with rotation as indicated by a curve b in FIG. 4, the optical head 2 is controlled by the control circuit with a wobbling signal as indicated by a curve a in FIG. Output to 17. Based on this surface wobbling signal, the control circuit 17 outputs a signal to the actuator 7 while watching the detection signal from the position sensor 15 so that the magnetic head 6 maintains a constant distance from the optical disk 1, and The absolute height position of the head 6 is feedback-controlled. That is, when the actuator 7 is actuated by a signal from the control circuit 17 and the magnetic head 6 moves in the height direction by this, its absolute height position changes, and the absolute height position of this magnetic head 6 is detected by the position sensor 15. Then, the absolute height position of the magnetic head 6 is controlled to be changed by the actuator 7 until the relative distance between the magnetic head 6 and the optical disk 1 reaches the above-mentioned fixed distance.

In this way, the absolute height position of the magnetic head 6 is maintained at the constant distance H as shown by the curve c in FIG. Data can be smoothly recorded on the optical disc 1, and even when the surface deflection of the optical disc 1 is large, it is possible to reliably prevent the magnetic head 6 from coming into contact with the optical disc 1 and damaging the optical disc 1 or the magnetic head 6. .. In this way, recording of data on the optical disc 1 is continued while preventing the magnetic head 6 from coming into contact with the optical disc 1, and when the recording of the data is completed, the feedback control is also terminated. By the way, FIG. 5 shows a block diagram of the feedback control system by the control circuit 17. Although the light source 8 is provided in the optical head 2 in the embodiment, the light source 8 may be provided in a place other than the optical head 2 as long as it is a stationary portion.

[0011]

As described above, according to the present invention, the control means inputs the surface deflection signal from the optical head and the detection signal of the absolute height position of the magnetic head from the position sensor, and the magnetic head. The height position of the magnetic head is controlled by outputting a signal to an actuator that changes the absolute height position of the magnetic head. By controlling in this way, the distance between the magnetic head and the optical disk can be kept substantially constant, and even when the surface wobbling of the optical disk is large, it is possible to reliably prevent the magnetic head from contacting the surface of the optical disk. It is possible to prevent damage to the magnetic head and the optical disc. Further, according to the present invention, as compared with the conventional optical recording / reproducing apparatus, a new optical system or the like is not required, and the magnetic head driving unit can be made smaller and lighter, and since the magnetic head driving unit is provided, Lift-up can be easily performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an optical recording / reproducing apparatus according to the present invention.

FIG. 2 is a block diagram showing a control system of the optical recording / reproducing apparatus shown in FIG.

FIG. 3 is a flowchart showing an operation procedure of the optical recording / reproducing apparatus shown in FIGS.

FIG. 4 is a diagram showing a relationship between surface wobbling of an optical disk, a focus position of light from an optical head, and an absolute height position of a magnetic head.

FIG. 5 is a block diagram showing a feedback control system by a control circuit.

[Explanation of symbols]

 1 Optical Disc 2 Optical Head 3 Objective Lens 4 Carriage 6 Magnetic Head 7 Actuator 8 Light Source 10-12 Reflection Mirror 15 Position Sensor 17 Control Circuit

Claims (4)

[Claims] 1. An optical disk for recording data, an optical head for projecting light on the optical disk to record and reproduce data, and for outputting a surface wobbling signal of the optical disk, and an optical disk used for recording data on the optical disk. A magnetic head arranged on the opposite side of the optical head, an actuator for changing the absolute height position of the magnetic head, a position sensor for detecting the absolute height position of the magnetic head, and a surface deflection from the optical head. An optical recording / reproducing apparatus comprising: a control unit for controlling a height position of the magnetic head by inputting a signal and a detection signal from the position sensor and outputting the signal to the actuator. 2. The optical recording / reproducing apparatus according to claim 1, wherein the control unit controls the distance between the magnetic head and the optical disk to be substantially constant. 3. The position sensor detects the absolute height position of the magnetic head based on the incident position of the light from a stationary light source reflected by a reflection mirror provided on the magnetic head. The optical recording / reproducing device according to claim 1. 4. The optical recording / reproducing apparatus according to claim 1, wherein the optical head outputs a surface wobbling signal of the optical disk in association with focus control for focusing light projected on the optical disk.