JPH0562280A - Heat radiating device of magnetic head - Google Patents

Abstract

PURPOSE:To provide the heat radiating device which prolongs the life of a magnetic head, decreases the thermal damages to be applied to the parts around the magnetic head and normal operates an optical gap sensor. CONSTITUTION:The magnetic head 12 has a heat radiating plate 16 and impresses magnetic field to a magneto-optical disk 1. The optical gap sensor 13 detects the gap between the magneto-optical disk 1 and the magnetic head 12. The distance between the magneto-optical disk 1 and the magnetic head 12 is maintained constant in accordance with the output of the optical gap sensor 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat dissipation device for a magnetic head of a magneto-optical disk recording / reproducing apparatus.

[0002]

2. Description of the Related Art Magneto-optical disks capable of high-density recording and reproduction have been put into practical use. In the magneto-optical disk recording / reproducing apparatus, it is desirable to reduce the gap between the magnetic field coil and the magneto-optical disk in order to efficiently orient the magnetic field in the recording film of the magneto-optical disk. Therefore, as shown in FIG. 8, in order to minimize the gap between the magneto-optical disk 101 and the magnetic field coil 102, the magneto-optical disk 10 is used.
1 and the magnetic field coil 102 may be brought into contact with each other via the active sheet. That is, FIG. 8 is a principle diagram showing the method, and the facing surface 101 of the magneto-optical disk 101 is shown.
The active sheet 101b is pasted on a. One end of a spring 111 is attached to the magnetic field coil 102. The other end of the spring 111 is fixed. The magnetic coil 102 is pressed against the active sheet 101b by the pressing force of the spring 111. As a result, the magnetic field coil 102 is held in a fixed state with respect to the magneto-optical disk 101.

However, in the case of the method shown in FIG. 8, since the magnetic field coil 102 is pressed against the active sheet 101b, there is a risk that the magnetic coil 102 will stick to the magneto-optical disk 101 or the magnetic coil 102 itself will wear. Moreover, an excessive load may be applied to a spindle motor (not shown) for rotating the magneto-optical disk 101.

Therefore, the magneto-optical disk recording / reproducing apparatus is provided with a control mechanism that allows the magnetic field coil to maintain a certain distance from the magneto-optical disk.

That is, as shown in FIG. 9, a magnetic field coil 102 for applying a magnetic field to the magneto-optical disk 101 is embedded in the base 103. A light emitting element 104 that irradiates the facing surface 101a of the magneto-optical disk 101 with diffused light is embedded in the base 103. Further, a pair of light receiving elements 105 and 106 for receiving the diffused light from the light emitting element 104 reflected by the facing surface 101a is embedded.

The light receiving elements 105 and 106 are connected to the differential amplifier 107. The differential amplifier 107 includes the light receiving element 1
The level difference between the output voltage a of 05 and the output voltage b of 106 is detected. The output of the differential amplifier 107 is used as the control current c, and the base 103 via the drive circuit
Is supplied to the drive coil 109 installed on the outer periphery of the. The drive coil 109 causes the magneto-optical disk 1 to move by the control current c.
It is driven in the direction (focus direction) indicated by t with respect to 01. That is, the drive coil 109 moves the magnetic field coil (magnetic head) 102 in the focus direction.

The moved magnetic field coil 102 is controlled so as to maintain a certain distance from the magneto-optical disk 101. Therefore, the gap between the magnetic field coil 102 and the magneto-optical disk 101 becomes small, and the magnetic field coil 1
02 and the magneto-optical disk 101 are prevented from contacting each other.

[0008]

In the method shown in FIG. 9, when the magnetic field coil 102 moves in the focus direction, the magnetic field coil 102 itself generates heat. Due to this heat,
The life of the magnetic field coil (magnetic head) 102 itself is shortened. Further, this heat is transmitted to the light emitting element 104 via the base 103, and the output of the light emitting element 104 is reduced by this heat. When the output of the light emitting element 104 decreases, the amount of diffused light reflected from the magneto-optical disk 101 also decreases. Therefore, the output voltages a and b supplied from the light receiving elements 105 and 106 to the differential amplifier 107 become inaccurate. Therefore, the servo cannot be properly applied to the drive coil 109.

Therefore, an object of the present invention is to radiate the heat generated when the magnetic field coil (magnetic head) is moved,
(EN) A heat dissipation device for a magnetic head capable of minimizing the temperature rise of the magnetic field coil, attenuating the thermal damage to the parts around the magnetic field coil, and operating the gap sensor normally.

[0010]

The present invention is directed to a disk as a data recording medium, a magnetic head for applying a magnetic field to the disk, and an optical gap sensor for detecting a gap between the disk and the magnetic head. And a mechanism for keeping the distance between the disk and the magnetic head constant based on the output of the optical gap sensor, and at least the heat dissipation means is provided in the magnetic head.

[0011]

By attaching a heat sink to the magnetic head, the heat generated when the magnetic head is moved is radiated to minimize the temperature rise of the magnetic head, and the thermal damage to the parts around the magnetic head is minimized. And the gap sensor operates normally.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the present invention. In FIG. 1, a magneto-optical disk 1 comprises a disk substrate 2, a recording section 3, and a transparent protective plate 4. An optical pickup unit 7 is provided at one end of the U-shaped arm 6 and a magnetic head unit 8 is provided at the other end. The optical pickup unit 7 and the magnetic head unit 8 are integrally moved by the arm 6 in the radial direction of the magneto-optical disk 1.

In the magnetic head unit 8, the base 9 is movable in the focus direction by the actuator 10. A magnetic head 12 is provided on the base 9. The magnetic head 12 has a magnetic field coil 11 for applying a magnetic field according to an information signal or a predetermined bias magnetic field to the magneto-optical disk 1. An optical gap sensor 13 is provided near the magnetic head 12. As shown in FIG. 2, the optical gap sensor 13 includes a light emitting element 14 and a pair of light receiving elements 15a and 15b. Optical gap sensor 1
3 is embedded in the base 9 so that a part of the transparent protective plate 4 of the magneto-optical disk 1 is exposed.

The light emitting element 14 in the optical gap sensor 13
Is for irradiating the transparent protective plate 4 of the magneto-optical disk 1 facing the magnetic field coil 11 with diffused light, and is composed of, for example, a light emitting diode (LED). In addition, the light receiving element 15a
And 15b receive the diffused light emitted from the light emitting element 14 to the transparent protective plate 4, and supply an output voltage to the actuator 10 according to the amount of received light. Light receiving elements 15a and 15b
Is composed of, for example, a photodiode, and
It is arranged on both sides with the pinch in between.

A heat sink 16 is attached to the magnetic head 12 by, for example, screwing after it is fitted. The heat dissipation plate 16 is parallel to the magneto-optical disk 1 and has a shape covering the outer peripheral surface of the magnetic head 12, and the heat dissipation plate 16 as a whole has a circular or polygonal plate shape. Further, the hole 31 for the optical gap sensor is provided so that the heat generated from the magnetic head 12 is easily dissipated. The heat sink 16 is
For example, it is formed of a metal such as copper having high thermal conductivity. If a sufficient heat radiation effect cannot be obtained with this heat radiation plate 16 alone, the structure may be such that heat is radiated via the base 9 and the arm 6. In this case, the materials of the base 9 and the arm 6 are
It is based on the heat radiating plate 16, and the armature 6 is required to have the ataturator 10 formed to conduct sufficient heat.

FIG. 3 is an enlarged view of the magnetic head portion 8 in FIG. As can be understood from FIG. 3, the heat generated in the magnetic field coil 11 passes through the magnetic head 12 and the heat sink 1
Heat is radiated from 6. Since the heat dissipation plate 16 is plate-shaped as described above, it has a function of expanding the surface area of the magnetic head 12 and enhancing the heat dissipation effect.

FIG. 4 shows a second embodiment of the present invention.
In FIG. 4, in order to enhance the heat dissipation effect, for example, a plurality of slit-shaped grooves 17a at equal intervals are provided in a part of the heat dissipation plate 17 having a shape parallel to a magneto-optical disk (not shown).
Is provided. Since the groove 17a is formed in the circumferential direction of the magneto-optical disk, the wind force generated by the rotation of the magneto-optical disk flows through the groove of the heat radiating plate 17 to obtain an increased surface area and a high heat radiating effect. Will be possible.

FIG. 5 shows a third embodiment of the present invention.
In FIG. 5, the shape of the heat radiation fin 18 is a fin shape unlike the plate shape like the heat radiation plates 16 and 17 described above.
The heat radiation fins 18 are in close contact with the outer circumference of the magnetic head 12.
In addition, the size and mass of the radiator plates 16 and 17 can be made smaller and lighter than the radiator plates 16 and 17 described above. Therefore, the influence on the mass and inertial mass of the head is small, and the influence on the servo response can be minimized.

FIG. 6 shows a fourth embodiment of the present invention.
In FIG. 6, a radiation fin 18 is attached to the outer circumference of the magnetic head 12, and a radiation fin 19 is attached to the outer circumference of the base 9. Therefore, the heat generated in the magnetic field coil 11 is transmitted through the magnetic head 12 and the base 9 to the radiating fin 1
Heat is radiated from 8 and 19. In this way, since the surface area for radiating heat is large, the heat radiating effect is large.

FIG. 7 shows a fifth embodiment of the present invention.
In FIG. 7, the base 20 itself has the shapes of the base 9 and the radiation fin 19 of the above-described fourth embodiment. Further, the magnetic head 21 itself has the shape of the magnetic head 12 and the heat radiation fin 18 described above. Therefore, as shown in FIG. 6, the same heat dissipation effect can be obtained without separately disposing the heat dissipation fins 18 and 19 on the magnetic head 12 and the base 9.

In the above embodiment, the present invention is applied to the magneto-optical disk recording / reproducing apparatus, but the present invention is not limited to this.

[0022]

According to the present invention, the heat generated from the magnetic head can be dissipated by attaching the heat dissipation device to the magnetic head. Therefore, the temperature rise of the magnetic head can be minimized to prolong the life of the magnetic head, and heat generated from the magnetic head can be prevented from being transmitted to the light emitting element of the optical gap sensor and disturbing the gap servo. In addition, it is possible to reduce the thermal damage to the parts around the magnetic head.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment to which the present invention is applied.

FIG. 2 is a perspective view of an optical gap sensor.

FIG. 3 is an enlarged view of a magnetic head unit.

FIG. 4 is a sectional view of a head portion showing a second embodiment to which the present invention is applied.

FIG. 5 is a sectional view of a head portion showing a third embodiment to which the invention is applied.

FIG. 6 is a sectional view of a head portion showing a fourth embodiment to which the present invention is applied.

FIG. 7 is a sectional view of a head portion showing a fifth embodiment to which the present invention is applied.

FIG. 8 is a principle diagram for explaining a conventional technique.

FIG. 9 is a cross-sectional view showing a configuration of an example of a conventional head-one controller.

[Explanation of symbols]

 1 Magneto-optical disk 8 Magnetic head part 13 Optical gap sensor 16, 17 Radiating plate 18, 19 Radiating fin 20 Base 21 Magnetic head

Claims (1)

[Claims] 1. A disk as a data recording medium, a magnetic head for applying a magnetic field to the disk, an optical gap sensor for detecting a gap between the disk and the magnetic head, and the optical gap. A heat dissipation device for a magnetic head, comprising a mechanism for keeping a constant distance between the disk and the magnetic head based on an output of a sensor, and at least a heat dissipation means being provided in the magnetic head.