JPS60167170A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To maintain a clamping mechanism in releasing state for a specified time by converting rotational energy of a spindle motor in a magnetic disk device and applying current to a solenoid at the time of momentary break or momentary stop of a power source. CONSTITUTION:When the output of a power source 31 is stopped, power is not supplied to the spindle motor 32. However, the motor continues to rorate by inertia. Meanwhile, counter electromotive force generated by rotation is supplied to a coil 34 from the input terminal of the motor 32 through diodes 35a- 35f. Accordingly, the clamping mechanism 4 does not operate until the spindle motor becomes to have the rotation below specified number of rotation. Normally, time required until the head retreats to a retract zone is several hundreds milisec. However time required for the spindle motor 32 to become below specified number of rotation is several seconds to ten-odd sec, the clamping mechanism operates after the head has fully retreated to the retract zone.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic disk device, and particularly to a clamp mechanism for clamping a head positioning mechanism.

[Prior art]

Conventionally, there have been devices of this type as shown in FIGS. 1 and 2. In the figure, l is a magnetic head, 2 is a head positioning mechanism, 3 is a melon for clamping which is a part of the head positioning mechanism 2, 4 is a clamp mechanism for clamping the positioning mechanism 2, and 5 is the clamp mechanism. This is a solenoid that rotates 4. The above head positioning mechanism 2
is rotatably supported via a rotating shaft (not shown), and has an arm 2a that holds the magnetic head 1, and an actuator 2b that is made of a magnet, a coil, etc., and that applies rotational force to the positioning mechanism 2. By controlling the positioning mechanism 2, the head 1 can be made to correspond to a predetermined data track on a magnetic disk rotated by a spindle motor (not shown).

A locking piece 5b protrudes from the rotating shaft 5a of the solenoid, and as this locking piece 5b rotates and comes into contact with the tape surface 3a of the melon 3, a pressing force is applied to the actuator 2b side. The solenoid 5 has a spring that rotates the lock piece 5b in the direction of the arrow 6a, and an electromagnetic coil that rotates in the opposite direction to the arrow 6a against the spring.

Next, the operation will be explained. When the device is not powered, the coil of the solenoid 5 is deenergized, the clamp mechanism 4 is rotated in the direction of the arrow 6a by the spring inside the solenoid 5, and the head positioning mechanism 2 is rotated by pushing the melon 3. Arrow 6b.

The head positioning mechanism 2 is rotated in the direction 6C, and is clamped by coming into contact with a stopper (not shown) to prevent unnecessary rotation of the head positioning mechanism 2. When the device is powered on, the coil of the solenoid 5 is energized, the clamp mechanism 4 rotates in the opposite direction to the arrow 6a, and the head positioning mechanism 2 is released from the clamp.

However, according to conventional magnetic disk drives, if the power supply is momentarily cut off or stopped for some reason during the operation of the machine, current will no longer flow through the solenoid, so the head 1 will be retracted to the retract zone. The mechanism 4 may rotate in the direction of the arrow 6a. At this time, the head positioning mechanism 2 collides with the clamp mechanism 4 and is subjected to a large impact force by the clamp mechanism 4, resulting in disadvantages such as misalignment of the mounting position of the head.

[Summary of the invention]

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional technology, and it converts the rotational energy of the spindle motor in the magnetic disk drive into electrical energy and energizes the solenoid when the power supply is momentarily interrupted or interrupted. By doing so, the clamp mechanism is held in the released state for a certain period of time.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Third
The figure is a block diagram showing an embodiment of a magnetic disk device according to the present invention. In the figure, 31 is a power source, 32 is a spindle motor that rotates the magnetic disk, and 33 is a spindle motor that drives the spindle motor 32. A drive circuit 34 is a solenoid coil that rotates the clamp mechanism 4, and 35a to 35f form a closed circuit with the coil 34 when the power supply 31 is momentarily cut off or stopped, and prevents back electromotive force from the input terminal of the spindle motor 32. A diode 36 is a diode for applying power to the coil 34, and a diode 36 is a diode for applying the output of the power source 31 directly to the coil 34.

Next, the operation will be explained. When the power supply 31 outputs a specified voltage, that voltage is applied to the coil 34 through the diode 36. Therefore, the clamp mechanism 4 rotates, and the clamp on the head positioning mechanism 2 is released.

When the magnetic disk device is performing seek, read, and write operations, the voltage of the power supply 31 is applied to the spindle motor 32, so that the motor 32 rotates at a constant speed. When the output of the power supply 31 stops, the spindle motor 32
Power is no longer supplied to it, but it continues to rotate because of its inertia. During this time, the back electromotive force generated by the rotation is transferred from the input terminal of the motor 32 to the diodes 352 to 35.
f and is supplied to the coil 34. Therefore, the clamp mechanism 4 does not operate until the spindle motor 32 reaches a specified number of rotations or less. Normally, the time required for the head to retract to the retract zone is several hundred milliseconds, but it takes several seconds to more than ten seconds for the spindle motor 32 to fall below the specified rotation speed, so the head completely returns to the retract zone. After retraction, the clamp mechanism will operate.

In the above embodiments, a rotary type clamp mechanism has been described, but the present invention can also be applied to a linear motion type clamp mechanism, and other circuit elements that use electric energy instead of a solenoid can be used. It's okay.

〔Effect of the invention〕

As described above, according to the present invention, the rotational energy of the spindle motor in the magnetic disk drive is converted into electrical energy and energized to the solenoid when the power supply is interrupted or interrupted for a certain period of time. can be held in a released state, preventing the head positioning mechanism from colliding with the clamp mechanism, and improving reliability.

[Brief explanation of the drawing]

1 and 2 are a perspective view and a plan view showing an example of a clamp mechanism in a conventional magnetic disk device, and FIG. 3 is a circuit configuration diagram showing an embodiment of a magnetic disk device according to the present invention. 1... Magnetic head, 2... Head positioning mechanism, 3
... Melon, 4 ... Clamp mechanism, 5 ... Solenoid, 31 ... Power supply, 32 ... Spindle motor, 33
...Spindle motor drive circuit, 34..., U-il, 35a to 35f. 36... Diode. Agent Masuo Oiwa (2 idiots) Figure 1 13 Figure 1 Procedural amendment (Mr. Commissioner of the Japan Patent Office 1, Indication of case: Japanese Patent Application No. 59-022200 2, Title of invention: magnetic disk device 3, Amendment) 5. Column for detailed explanation of the subject invention of the amendment. 6. Contents of the amendment + 11 The text "melon" on page 2, lines 5 and 17 of the specification, and on page 3, line 6. Correct as “claw”.

Claims (1)

[Claims] a motor that applies rotational force to a magnetic disk; a positioning mechanism that positions a magnetic head at a predetermined position on the magnetic disk; an elastic member that applies force in a certain direction to the positioning mechanism to clamp the positioning mechanism at a predetermined position; In a magnetic disk drive including a clamping mechanism having a coil that applies an electromagnetic force to release the clamp against an elastic member, the back electromotive force of the motor is applied between the input terminal of the motor and the coil. A magnetic disk device characterized by forming an energizing circuit that energizes a coil.