JPS6182382A - magnetic recording device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a magnetic recording device.

[Prior Art] Conventionally, in a magnetic recording device, a magnetic head is controlled to move back and forth in the radial direction on a magnetic disk, which is a storage medium, to position the magnetic head at a corresponding track position and write or read information. I try to do it.

In this case, a zero track position is provided at a predetermined position on the outer periphery of the magnetic disk, and when the magnetic head reaches the zero track position, it is rotated by the rotation of a stepping motor that controls the movement of the magnetic head using, for example, an optical zero track sensor. The operated interrupter member is detected and outputted to a central processing unit (CPU), which stops the operation of the stepping motor and determines the home position of the magnetic head.

[Problems to be solved by the invention] However, in such a device, if the CPU program goes out of control for some reason, the magnetic head will not stop even though the zero track sensor has detected the zero track position. Furthermore, the magnetic head is moved outside the magnetic disk, resulting in the magnetic head coming off the magnetic disk, making it impossible to write or read information, or causing damage to the magnetic head and the magnetic disk.

This invention was made to solve these problems. Even if the central processing unit goes out of control, the magnetic head can be reliably stopped on the storage medium, and the magnetic head can then be brought to zero track. It is an object of the present invention to provide a magnetic recording device that can be returned to its original position and ready for the next operation.

[Means for Solving the Problems] This invention provides a disc-shaped storage medium for storing information;
A rotation mechanism is provided to fix the storage medium and rotate it at a constant speed, and a rotation mechanism is provided that is movable in the radial direction of the storage medium rotated by this rotation mechanism, and is provided to write and read information to and from the storage medium. a stepping motor that controls the movement of the magnetic head; a member that is attached to the rotating part of the stepping motor and rotates with the rotation of the motor; A zero track sensor detects the zero track by detecting the rotational position of the member when it moves to the track position, and a magnetic head is installed near the zero track sensor to move the magnetic head to a predetermined position outside the zero track position on the storage medium. A moving position limit sensor that detects the position of a member when it moves, a central processing unit that programmatically controls the rotation mechanism, magnetic head, stepping motor, zero track sensor, etc., and a central processing unit that uses the member detection output from the moving position limit sensor. means for inputting a short-time reset signal to the central processing unit, and the central processing unit returns the magnetic head to the zero track position on the storage medium by inputting the reset signal.

[Operation] With this structure, even if the central processing unit runs away with the program and the magnetic head is moved outside the zero track position of the storage medium, the movement position limit sensor will be able to move it. The CPU detects this and resets the central processing unit, thereby prohibiting further outward movement of the magnetic head, returning the program to its initial state, and returning the magnetic head to the zero track position.

[Embodiments of the invention] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial view showing the configuration of the main parts, where 1 is a magnetic disk which is a storage medium, and 2 is a plate that holds the magnetic disk 1 in place. The holding plate 2 is rotated together with the magnetic disk 1 by a spindle motor, which will be described later. 3 is a magnetic head, 4
is an arm to which the magnetic head 3 is attached at its tip, and is rotatable clockwise and counterclockwise about the other end, and controls the reciprocating movement of the magnetic head 3 in the radial direction of the magnetic disk 1; , 5 is a pulley rotatably operated by a stepping motor which will be described later; 6 is a pulley whose end surface is in contact with the pulley 5 via a belt or the like, and whose other end is rotatable about the same axis as the arm 4; It is an actuator. That is, the arm 4, the pulley 5
, the relationship with the actuator 6 is that when the pulley 5 is rotated by the stepping motor, the actuator 6
rotates clockwise or counterclockwise about the other end, thereby causing the arm 4 to rotate.

The tip of the actuator 6 is fan-shaped, and the rotation range of the pulley 5 is determined by the length of the tip. This rotation range is determined so that the magnetic head 3 can move in the radial direction of the magnetic disk 1 with sufficient margin. An interrupter member 7 that rotates with the rotation of the pulley 5 is attached to the lower part of the pulley 5, and when the magnetic head 3 just reaches the zero track position on the magnetic disk 1, the interrupter member 7 is positioned to interrupt the optical path. For example, an optical zero track sensor 8 is provided. In the vicinity of the zero track sensor 8, when the magnetic head 3 passes through the zero track position, moves further outward, and comes just before the position where it comes off the top of the magnetic disk 1, the optical path is interrupted by the interrupter member 7. For example, an optical movement position limit sensor 9 is provided at the position.

FIG. 2 shows a circuit showing a control section, and 11 is a reset terminal RE.
A central processing unit (hereinafter referred to as CPU) with SET.

), 12 is an I10 port, and 13 is a transmission interface. The CPU 11 has a built-in ROM that stores program data, a RAM that stores control information, and the like. The CPU 11 controls the I10 port 12 via a pass line 14, and controls the magnetic head 3.
It outputs information to and takes in information from the head thereof, takes in information from the zero track sensor 8, and controls the motor drive circuit 15 to drive the stepping motor 16 and motor drive circuit 17 described above.
is controlled to drive the spindle motor 18 mentioned above. Further, the CPU 11 controls the transmission interface 13 via the path line 14, and controls the transmission of information and signals with the host computer.

The movement position limit sensor 9 is composed of a light emitting element 9a and a light receiving element 9b, and the output of the light receiving element 9b is supplied to a ten-input stator of an operational amplifier 19.

A reference voltage from a reference voltage setting circuit 20 is input to one input terminal of the operational amplifier 19. The output of the operational amplifier 19 is supplied to the input terminal A of a monostable multi-by-break 21 whose oscillation time is set by a capacitor C and a resistor R. The monostable multivibrator 2
1 supplies the output of its output terminal Q to the reset terminal RESET of the CPU 11.

The CPU 11 starts the program control operation shown in FIG. 3 when the power is turned on or when a reset pulse is input to its reset terminal RESET and the input is stopped. That is, first, the ports and RAM are initialized, and then the rotation of the spindle motor 18 is started. Then, it is checked whether the spindle motor 18 is rotating normally or not, and if it is abnormal, the progress of the program is stopped. Further, if the spindle motor 18 is rotating normally, it is next checked to see if there is any abnormality in anything other than the spindle motor 18, and if there is an abnormality, a write inhibit output is sent out to stop the transition program control. If there is no abnormality as a result of this check, the magnetic head 3 is moved to a position where the zero track sensor 8 detects the interrupter member 7 and set at the home position. Subsequently, the write protection is canceled and the movement of the magnetic head 3 is controlled by signal input from the host computer to write and read information.

In the device according to the embodiment of the present invention having such a configuration, the CPU 1
As long as the magnetic head 1 is operating normally without program runaway, the magnetic head 3 is always set at the zero track position and positioned at the home position, and writes and reads information to and from each track.

However, if the CPU 11 runs out of control for some reason, positioning at the home position becomes impossible, and for example, a situation occurs in which the magnetic head 3 is moved further outside than the zero track position.

When such a situation occurs, the interrupter member 7 will further rotate clockwise due to the rotation of the pulley 5. Thus, the optical path of the movement position limit sensor 9 is interrupted by the interrupter member 7. When this happens, the output of the operational amplifier 19 is inverted from high level to low level, and at the fall of the output, the monostable multivibrator 2
1 works. However, that multivibrator 21
A short-time low-level reset signal determined by the time constants of the capacitor C and the resistor R is input from the output terminal Q of the CPU 11 to the reset terminal RESET of the CPU 11, and CPtJll is reset. As a result, the CPU 11 resets the program, stops the operation of the stepping motor 16, and stops the outward movement of the magnetic head 3. When the input of the reset signal is stopped, the CPIJll starts program control from the beginning, and the magnetic head 3 is thereby returned to the zero track position of the magnetic disk 1, that is, the home position. Therefore, when write or read information is input, the magnetic head 3 can immediately operate.

In this way, even if the CPIJll program runs out of control, the magnetic head 3 will move too far outside and the magnetic head 3 will come off the magnetic disk 1, making it impossible to read or write information. There is no risk of damage. Moreover, since the magnetic head 3 returns to its home position and waits for the next operation, it is possible to operate quickly for writing and reading information. Furthermore, there is a risk that the magnetic head 3 may move too far inside the magnetic disk 1 due to program runaway, and the presser may collide with the root 2.

In this case, the interrupter member 7 rotates counterclockwise to similarly interrupt the optical path of the movement position limit sensor 9. However, in this case as well, the CPU 11 is reset, the movement of the magnetic head 3 is stopped, and the magnetic head 3 is then returned to the home position.

In the above embodiment, an example was described in which optical sensors were used as the zero track sensor and the movement position limit sensor, but they are not necessarily limited to this (for example, even if a micro switch good.

[Effects of the Invention] As detailed above, according to the present invention, even if the central processing unit goes out of control, the magnetic head can be reliably stopped on the storage medium, and the magnetic head can then be returned to the zero track position. Therefore, it is possible to provide a magnetic recording device that can wait for the next operation.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, in which Fig. 1 is a partial diagram showing the configuration of the main part, Fig. 2 is a circuit diagram of the main part, and Fig. 3 is a CPU.
2 is a flowchart showing main part processing by. 1...Magnetic disk, 2...Platform with presser, 3...
Magnetic head, 4...arm, 5...pulley, 6...
・Actuator, 7... Interrupter member, 8...
・Zero track sensor, 9... Movement position limit sensor, 11... Central processing unit (CPU), 16...
・Stepping motor, 18... spindle motor,
19... operational amplifier, 21... monostable multivibrator. Applicant's agent Patent attorney Takehiko Suzue Figure 3

Claims (1)

[Claims] A disc-shaped storage medium for storing information, a rotation mechanism for fixing the storage medium and rotating it at a constant speed, and a rotation mechanism for rotating the storage medium at a constant speed, and a disk-shaped storage medium for storing information, and a rotation mechanism for rotating the storage medium at a constant speed. a magnetic head that writes and reads information to and from the storage medium; a stepping motor that controls the movement of the magnetic head; and a member that is attached to the rotating part of the stepping motor and that rotates as the motor rotates. , a zero track sensor that detects the rotational position of the member to detect zero track when the magnetic head moves to a zero track position set on the outer circumferential side of the storage medium; and a zero track sensor provided near the zero track sensor. , a movement position limit sensor that detects the position of the member when the magnetic head moves to a predetermined position outside the zero track position on the storage medium;
A central processing unit that programmatically controls the rotation mechanism, magnetic head, stepping motor, zero track sensor, etc., and means for inputting a short-time reset signal to the central processing unit based on the member detection output from the movement position limit sensor. The magnetic recording device is characterized in that the central processing unit returns the magnetic head to a zero track position on the storage medium by inputting a reset signal.