JPS6355153B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a floppy disk drive device used for external memory and the like.

[Technical background of the invention and its problems]

A floppy disk drive device rotates the floppy disk using a disk rotation drive mechanism, and makes it possible to write and read information on the floppy disk by bringing a head into contact with the surface of the floppy disk. In such an apparatus, if the head is driven in contact even though the floppy disk is not set, there is a risk that the head will malfunction. For this reason, in the past, a separate device was installed to detect the presence or absence of a floppy disk, and unless this device detected that a floppy disk was set, the head drive was prohibited even if a head drive signal was input. . However, such a conventional method requires a dedicated device for detecting a floppy disk, which has the drawback of complicating the device and increasing its size.

By the way, a floppy disk drive device is provided with an index sensor, which detects a hole provided in the floppy disk surface every time the disk rotates to obtain an index signal.
From this, for example, it is conceivable to determine whether the floppy disk is set by counting several index signals, and to contact drive the head based on this determination and the head drive signal.
However, in this case, it takes time for the head to come into contact with the disk surface after the rotation of the floppy disk starts, resulting in a problem that the start-up is slow.

[Purpose of the Invention] This invention was made to solve these problems, and it is possible to detect the presence or absence of a floppy disk with a simple configuration, and also to prevent the head from coming into contact with the disk surface from the start of rotation of the floppy disk. An object of the present invention is to provide a floppy disk drive device which can sufficiently shorten the time required to complete the process.

[Summary of the invention]

This invention uses an existing index sensor to detect the presence or absence of a floppy disk, and uses the index signal of the index sensor to generate a retriggerable device whose output pulse width is set to be longer than the period of one rotation of the floppy disk. The one-shot multivibrator is energized, and the head can be driven by contact when the multivibrator output is sent out.

[Embodiments of the invention]

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

In FIG. 1, reference numeral 1 denotes a base, through which a rotating shaft 2 of a motor forming a disk rotation drive mechanism is passed through the base 1, and a holder that holds a floppy disk 3 at the tip of the rotating shaft 2. A body 4 is attached. Further, a head drive mechanism 6 is provided on one side of the base 1 so as to be slidable with respect to the slide shaft 5, and a support 8 for supporting one end of the lid 7 is provided at one end. There is. Approximately at the center of the lid 7, when the lid 7 is closed, it passes through a hole made in the center of the floppy disk 3 and fits into a recess 9 formed in the center of the holder 4; A disk fixing member 10 for fixing the floppy disk 3 is provided. A hole 11 for an index is provided on the outside of the disk surface of the floppy disk 3, and an index sensor 14 consisting of a light emitting diode 12 and a phototransistor 13 is provided on both sides of the disk surface with the hole 11 interposed therebetween. There is.

As shown in FIG. 2, the head drive mechanism 6 includes a head body 62 which pivots one end of the head portion 61 and is rotatable up and down, and a head body 62 that is provided protruding from the side of the head portion 61 of the head body 62. A rotary lever 64 is attached to the other end of the rotary lever 64, and one end of the rotary lever 64 is fixed to the lower part of the arm 63 and the other end is pivotally supported so as to be able to freely rotate up and down. The solenoid 66 rotates one end of the rotary lever 64 downward against the spring force of the spring 65.

FIG. 3 is a circuit diagram of a main part, in which the light emitting diode 12 is connected to a DC power source through a resistor 15, and the phototransistor 13 is connected through a resistor 16. A connection point between the resistor 16 and the collector of the phototransistor 13 is connected to an input terminal B of a retriggerable one-shot multivibrator 18 via an inverter 17. The one-shot multivibrator 18 responds to the rise of the input signal to the input terminal B, for example, and sends out a pulse output from the output terminal Q, the pulse width of which is set to be longer than the time it takes for the floppy disk 3 to rotate once. be. Further, the one-shot multivibrator 18 has a signal inputted to its reset input terminal by an initial reset circuit 19 when the power is turned on. Said one shot
A NAND gate 20 for two inputs of the output of the multivibrator 18 and a signal HS for driving the head such as a head load signal and a drive select signal.
is supplied to. The output terminal of the NAND gate 20 is connected to the base of a PNP transistor 21 which together with the NAND gate 20 forms an output control means. The transistor 21 is connected to the DC power source.
The solenoid 66 is connected through the solenoid 66.

In such a configuration, floppy disk 3
is held by the holder 4, the lid 7 is closed, and the floppy disk 3 is fixed. In this state, the power is turned on, the rotating shaft 2 is rotated by the motor, and the floppy disk 3 is rotated. But floppy disk 3
When the hole 11 on the disk surface passes the set position of the index sensor 14, a pulse signal is outputted via the inverter 17, and the one-shot multivibrator 18 is operated by the rise of this pulse signal. Since the next pulse signal is input before the output of the one shot multivibrator 18 falls, the multivibrator 18 is retriggered and a high level signal is continuously output from the output terminal Q. Therefore, in this state, when the signal HS for driving the head section 61 into contact with the floppy disk 3 is input, the output of the NAND gate 20 becomes low level, the transistor 21 is turned on, and the solenoid 66 is turned on.
is energized. As a result, the rotary lever 64 rotates in a direction to lower one end thereof against the spring force of the spring 65, so that the head portion 61 rotates downward and comes into contact with the floppy disk 3.

Further, when the floppy disk 3 is not set, no pulse signal is outputted via the inverter 17, so the one-shot multivibrator 18 is held in a non-operating state. Even if the signal HS is input, the output of the NAND gate 20 remains at a high level, and the transistor 21 remains off. Therefore, at this time, the solenoid 66 is not operated and one end of the rotary lever 64 remains raised, so that the head portion 61 is not driven by contact.

In this way, the existing index sensor 14 is used, and the output of the sensor 14 is used to trigger the trigger function.
The presence or absence of the floppy disk 3 can be detected with a simple configuration that energizes the one-shot multivibrator 18. Moreover, after the one-shot multivibrator 18 is energized by the output of the first index sensor 14, it is possible to contact drive the head section 61 by inputting the signal HS for driving the head at any time, so that the floppy disk can be rotated. The time from the start until the head contacts the disk surface can be sufficiently shortened.

〔Effect of the invention〕

As described above, the present invention provides a floppy disk drive device that can detect the presence or absence of a floppy disk with a simple configuration and can sufficiently shorten the time from the start of rotation of the floppy disk until the head contacts the disk surface. It is possible.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a side view showing the configuration of the main parts, FIG. 2 is a perspective view of the head mechanism, and FIG. 3 is a circuit diagram of the main parts. 2... Rotating shaft of motor, 3... Floppy disk, 4... Holder, 6... Head mechanism, 11...
...hole, 14... index sensor, 18...
Re-triggerable one-shot multivibrator, 21...PNP type transistor, 66...
…solenoid.

Claims (1)

[Claims] 1 A disk rotation drive mechanism, a floppy disk that can be attached to and removed from the disk rotation drive mechanism, and an index that repeatedly detects one rotation period of the floppy disk by the disk rotation drive mechanism and outputs an index signal. Tsukusu sensor and
A retriggerable one-shot multivibrator that is retriggered every time the index signal from this sensor is input and whose output pulse width is set to be longer than one rotation cycle time of the floppy disk, and the floppy disk. A head is provided so as to be movable toward and away from the surface of the floppy disk, a head drive mechanism drives the head into contact with the surface of the floppy disk, and a signal input is provided to drive the head when output from the one-shot multivibrator is sent out. and output control means for energizing the head drive mechanism.