JPS6352367A - Recording medium protecting device for disk device - Google Patents

Abstract

PURPOSE:To reduce the power consumption by supplying power to the electromagnet of a trigger magnet part from a backup power source to release pressing of a head if the power of a system power source is reduced. CONSTITUTION:When stop is selected, power supply to a motor 4 is stopped, and a head pressing release signal is outputted from a system control 6 after a prescribed time, and a switching means 16 is made conductive to supply power to an electromagnet 17, and then, a permanent magnet 18 is separated from a magnetic body 19 by the spring force and pressing of a head 5 to a recording medium 1 is released. Meanwhile, if the system power source is carelessly turned off in the reproducing or recording mode, a timer circuit 11 detects the reduction of power and outputs the head pressing release signal to a logic circuit 12 after a prescribed time. The logic circuit 12 sends the pressing release signal to a switching means 16, and the switching means 16 is made conductive to supply power to the electromagnet 17 from a backup power source 10, and a magnet part 13 is set to the non-connection position, and the head is not pressed to the recording medium 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording medium protection device for a disk device that prevents a recording medium from being deformed by the pressing force of a head.

[Summary of the Invention] The present invention is provided with a trigger magnet section that is made of an electromagnet, a permanent magnet, and a magnetic material and is displaced between a connected position where these are connected and a non-connected position where at least one member of these is disconnected, At the position, the head is in pressure contact with the recording medium, and at the uncoupled position, the head is arranged so as not to come into pressure contact with the recording medium. After a predetermined period of time has elapsed from the time of detection, a head pressure contact release signal is output from the timer circuit, and current is applied to the electromagnets of the trigger magnets in a direction that cancels out the magnetic force of the permanent magnets, thereby setting the trigger magnets to the uncoupled position. By releasing the pressure contact of the head, the power consumption can be reduced and the recording medium can be protected from the pressure contact force of the head even if the rinse stem power supply decreases for some reason.

[Prior Art] In a disk device that performs recording and reproduction by pressing a head against a recording medium, the recording medium deforms if the head is pressed against the recording medium for a long period of time. Therefore, a recording medium protection device is provided that protects the recording medium by preventing the head from coming into pressure contact with the recording medium except during recording and reproduction.

Conventional recording medium protection devices mechanically interlock the output lot of the plunger and pads arranged symmetrically with respect to the recording medium in the head, and when the plunger is energized, the pads are displaced in the direction of the recording medium, causing damage to the head or the recording medium. It is configured to be pressed into contact.

[Problems to be Solved by the Invention] However, the above-mentioned recording medium protection device has the disadvantage that power consumption is large because the plantar must be constantly energized during recording and reproduction.

On the other hand, in order to eliminate this drawback, the permanent magnet and the pad are interlocked, and the permanent magnet is provided so as to be movable between a coupling position where the permanent magnet is coupled to the fixed iron piece by magnetizing force and a non-coupling position where it is separated from the fixed iron piece. In this case, the head is brought into pressure contact with the recording medium, and the head is not brought into pressure contact with the recording medium at the non-coupling position. Then, at the start of recording/playback, a mechanical force is applied to the permanent magnets to set them at the coupling position, and the recording/playback is started.
Consider applying an external force that opposes the magnetic force to the permanent magnet again at the end of reproduction to bring the permanent magnet to the non-coupling position.

According to this means, it is only necessary to temporarily apply mechanical force only at the start of recording/playback and at the end of recording/playback, resulting in lower power consumption. However, if the system power is inadvertently cut off during recording/reproduction, the head will come into pressure contact with the recording medium and become stuck, and in such a case, deformation of the recording medium cannot be prevented.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a recording medium protection device for a disk device that can reduce power consumption and protect the recording medium even if the system power is cut off for some reason during recording or playback. .

Means for Solving Problem C] To achieve the above object, the present invention (14) provides a disk device comprising a recording medium that moves by the rotational force of a motor, and a head that is pressed against the recording medium. a backup power supply for backing up the power supply of the recording medium protection device when the system power supply decreases; and a backup power supply that detects the decrease in the system power supply and sends out a head pressure contact release signal after a predetermined period of time has elapsed from the time when the system power supply decrease is detected. a timer circuit that detects whether or not the voltage of the system power supply has dropped, and outputs a system control signal when the voltage of the system power supply is normal, and a signal of the timer circuit when the voltage of the system power supply has dropped. Part 4'
a logic circuit that selects and sends a head pressure contact release signal of the system control or the timer circuit to the trigger magnet unit; and an electromagnet, a permanent magnet, and a magnetic body, which are connected by the magnetic force of the permanent magnet. a trigger magnet section provided so as to be movable between a connected position and a non-connected position where at least one of these members is separated by energizing the electromagnet in a direction to cancel the magnetic force of the permanent magnet in response to the head pressure contact release signal; , a head pressure contact means mechanically interlocked with the trigger magnet unit so that the head comes into pressure contact with the recording medium in the connected position, and the head does not come into pressure contact with the recording medium in the unconnected position. do.

Therefore, during recording and reproduction, the trigger magnet section is in the connected position due to the magnetic force of the permanent magnet, and the head is pressed against the recording medium. When the system power is normal, the trigger magnet section is changed to the uncoupled position by the head pressure release signal from the system control, and when the system power decreases for some reason, the system control becomes inactive. When this system power supply drop is detected, a timer circuit using the backup power supply generates a head pressure release signal, and this head pressure release signal causes the trigger magnet portion to be moved to a non-coupling position.

[Example] Embodiments of the present invention will be described below based on the drawings.

An embodiment of the present invention is shown in FIGS. 1 and 2,
This embodiment shows a case where the present invention is applied to an electronic still camera, which is one type of disk device.

In FIG. 1, a hole 2 is formed in the center of a magnetic sheet, which is a recording medium 1, and a rotating shaft 3 is inserted into this hole 2. This rotating shaft 3 is connected to a motor 4, and the recording medium 1 is rotated by the rotational force of this motor 4.
:-The head 5 is fixed to the main body of the apparatus (not shown), and its tip is in contact with one surface of the recording medium 1.

The system control 6 outputs control signals to each circuit to perform operations such as recording, reproducing, and stopping in accordance with commands from operation buttons and the like. When the record/playback button is pressed, a drive signal is output to the motor 4, and after outputting this drive signal, a head pressure contact signal is generated, and when the stop button is pressed, a stop signal is output to the motor 4. At the same time, after a predetermined period of time has elapsed since outputting this stop signal, a head pressure release signal is issued to the trigger magnet section 13.

A system power is applied to this system control 6, and this system power is also applied to a recording medium protection circuit 9 via a diode 8.

This recording medium protection circuit 9 also has a backup power supply l.
O is provided and the system power is reduced (e.g.
When the power supply is cut off to an unused color (f), the recording medium protection circuit 9 is activated by this backup power supply lO. This backup power source IO may be configured with a Niracad rechargeable battery or a large capacity capacitor, and if configured in this way, it will be charged when the system power source is normal, so there is no need to worry about the battery running out.

The timer circuit 11 receives the voltage of the system power supply and detects a drop in the system power supply.The timer circuit 11 uses the falling part of the power supply voltage as a trigger to operate for a predetermined period of time (1) from this point.
Within this range, an L signal is output, and after a predetermined time (1) has elapsed, an H signal, which may be a head pressure release signal, is output. The predetermined time (1) is set to be longer than the time required from the time when the power supply to the motor 4 stops until the rotation of the recording medium 1 stops, and is appropriately determined based on the characteristics of the disk device.

The logic circuit 12 detects whether or not the voltage of the system power supply has decreased, and outputs a signal to the system control 6 when the voltage of the system power supply is normal, and outputs a signal to the timer circuit 11 when the voltage of the system power supply has decreased. It is configured to select each signal and send it to the trigger magnet section 13. In this embodiment, the logic circuit 12 is configured by combining an AND circuit 14 and an OR circuit 15.

The AND circuit 14 has its input terminal inputted with the inverted voltage of the system power supply voltage and the output of the timer circuit 11, and when the voltage of the system power supply decreases, the timer circuit 11 outputs the 11 signal. It outputs an H signal for the first time.

The output of the system control 6 and the output of the AND circuit 14 are led to input terminals of the OR circuit 15,
Its output terminal is connected to switching means 16.

Since this switching means 16 becomes conductive when the OR circuit 15 outputs an H signal, this switching means 16 is connected in series to an electromagnet 17 of the trigger magnet section 13 described below.

The trigger magnet section I3 includes an electromagnet 17. It consists of a permanent magnet 18 and a magnetic body 19. One terminal of the electromagnet 17 is connected to the switching means 16, and the other terminal is connected to the Nostem power source and the backup power source 10. This trigger magnet part 13 is energized in a direction to cancel the magnetic force of the permanent magnet 18 to the electromagnet 17 in response to the connection position where these are connected by the magnetic force of the permanent magnet 18 and the head pressure release signal. It is provided so as to be movable between a disconnected position and an uncoupled position. In this embodiment, the permanent magnet 18 is configured to be displaced away from the other members, and when the permanent magnet 18 is in the connected position, receives the spring force of the spring 20 in a direction away from the magnetic body 19.

The head pressure contact means 21 is provided with a pad 23 at a symmetrical position of the head 5 with respect to the recording medium I. This pad 23 is connected to the permanent magnet 18 via a link rod 24, and this link rod 24 rotates around a fulcrum. When the trigger magnet section 13 is in the connecting position, the pad 23 is pressed against the recording medium l and the head 5
is in pressure contact with the recording medium l. When the trigger magnet portion 13 is in the uncoupled position, the pad 23 is separated from the recording medium 1 and the head 5 is not pressed against the recording medium 1.

Further, when the recording/reproducing mode is selected by the operation button, the system control 6 issues a head pressure contact signal to the link rod 24, and a mechanical force is applied to the link rod 24 by this head pressure contact signal.

This mechanical force is applied in a direction that causes the permanent magnet 18 to approach the electromagnet 17 and the magnetic body 19.

Hereinafter, the operation of the recording medium protection device will be explained with reference to the time chart of FIG. 2.

Insert the recording medium l into the recording medium storage section and set it to be operable. When the playback or recording mode is selected by the operation button, the motor 4 rotates, and then a mechanical force is applied to the link rod 24, the permanent magnet 18 is displaced against the spring force, and the permanent magnet 18 is attracted to the magnetic body 19 by the magnetic force. do. When the trigger magnet section 13 reaches the connection position, the head 5 is brought into pressure contact with the recording medium I to perform reproduction or recording.

In the playback or recording mode, when stop is selected using the operation button, the power supply to the motor 4 is stopped. After a predetermined time (1) has elapsed since the power supply to the motor 4 was stopped, a head pressure release signal is output from the system control 6 (FIG. 2(e)), and this head pressure release signal causes the switching means 16 to become conductive. (Figure 2 (f)
) The electromagnet 17 is energized by the system power supply. When this electromagnet 17 is energized, the magnetic force of the permanent magnet 18 is canceled out, and the permanent magnet 18 is separated from the magnetic body 19 by the spring force, and the head 5 is no longer in pressure contact with the recording medium 1.

On the other hand, if the system power is inadvertently cut off during playback or recording mode (Fig. 2 (a)), the timer circuit 11 detects a drop in the system power; After a predetermined time (t) II has passed, a head pressure release signal is output to the logic circuit 12 (second
Figure (C)). This logic circuit 12 detects a drop in the system power supply and sends a pressure release signal of the timer circuit [1 to the switching means 16 (FIG. 2(d)).
. The switching means 16 is made conductive by the head pressure release signal (FIG. 2(r)), and the electromagnet 17 is energized by the backup power source 10.

When this electromagnet I7 is energized, the trigger magnet portion 13 is brought to the uncoupled position in the same way as described above, and the head 22 is no longer in pressure contact with the recording medium l.

In this embodiment, the head 5 was brought into pressure contact and non-IT contact with the recording medium 1 by displacing the pad 23 arranged at a symmetrical position of the head 22 with respect to the recording medium 1.
2. It is also possible to form a groove so as to displace itself and bring it into pressure contact or non-pressure contact with the recording medium 1.

[Effects of the Invention j As described above, according to the present invention, a predetermined backup power supply, a timer circuit, a logic circuit, a trigger magnet section, and a head pressure contact means are provided, and the pressure contact of the head to the recording medium is controlled by the trigger magnet section. The magnetic force of the permanent magnet is used to release the pressure contact between the head and the recording medium by energizing the electromagnet in the trigger magnet section.Also, when the system power supply drops, the backup power source is used to energize the electromagnet in the trigger magnet section. Make sure to release the pressure on the head.
This has the effect of reducing power consumption and preventing deformation of the recording medium due to the pressure contact force of the head even if the system power is cut off for some reason during reproduction or recording.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, FIG. 1 is a block diagram of a recording medium protection device, and FIG. 2 is a time chart showing the output of each part. 1... Recording medium, 4... Motor, 5... Head, 6
...System control, 10. Backup power supply, 11.. Timer circuit, 12. Logic circuit, 13.
- Trigger magnet part, 17... Electromagnet, 18... Permanent magnet, 19 Magnetic body, 21 Head pressure contact means.

Claims (1)

[Scope of Claims] In a disk device equipped with a recording medium that moves by the rotational force of a motor and a head that is pressed against the recording medium, the power supply of a recording medium protection device is backed up when the system power supply decreases. A backup power source; a timer circuit that detects a drop in the system power source and sends out a head pressure contact release signal after a predetermined period of time has elapsed from the time when the system power source drop is detected; and a timer circuit that detects whether or not the voltage of the system power source has dropped. , when the voltage of the system power supply is normal, the system control signal is selected, and when the voltage of the system power supply is decreased, the signal of the timer circuit is selected, respectively, and a trigger magnet triggers the head pressure contact release signal of the system control or the timer circuit. The electromagnet is made up of a logic circuit that sends out signals to the part, an electromagnet, a permanent magnet, and a magnetic body, and the electromagnet is energized in a direction to cancel the magnetic force of the permanent magnet according to the connection position where these are connected by the magnetic force of the permanent magnet and the head pressure release signal. a trigger magnet section that is displaceable to a non-coupled position where at least one of the members is separated from the other; A recording medium protection device for a disk drive, comprising: a head pressure contact means that presses the head against the recording medium in the non-coupled position.