JPH0536643U - Floppy disc device - Google Patents

Abstract

(57) [Summary] [Purpose] The timing of the index signal in a floppy disk device differs for each floppy disk device due to manufacturing variations. Therefore, in order to maintain the compatibility of floppy disks, conventionally, standard disks were used,
The adjustment work was done manually, but it was troublesome. It is an object of the present invention to provide a floppy disk device that electrically and automatically adjusts this adjustment. [Structure] A burst signal adjusting circuit 7 for adjusting a burst signal read from a standard disk 6 by a head 8.
A variable delay circuit 11 for delaying the index signal detected by the Hall element 5 by a delay amount, and an EEPROM 9 for storing an output signal corresponding to the delay amount sent from the burst signal adjusting circuit 7, and the variable delay circuit. The output signal of 11 is read by the burst signal adjusting circuit 7
It is given to the write circuit 12.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a floppy disk device having a function of automatically and properly adjusting the timing of index signals.

[0002]

[Prior Art]

 The floppy disk has a mechanical reference for making the read / write circuit know the start position of the data track. For example, in the case of a 130 mm floppy disk, an index signal is generated once per rotation by a through hole formed in the floppy disk and a photosensor provided in the floppy disk, and the position where the signal is detected starts the data track. The position is. Also, in the case of a 90 mm floppy disk, the rotor of the disk spindle motor and the disk are connected in a specific positional relationship, so that the index signal generator is often provided near the disk spindle motor. In any case, the index signal generation timing is not arbitrary and must be adjusted using a standard disk in order to maintain compatibility of the floppy disk which is a compatible medium. A conventional adjustment method will be described below with reference to FIG. The standard disc has a signal recorded on one specific data track by only one pulse. Hereinafter, this signal is referred to as a burst signal. The standard disk is inserted into the floppy disk device before adjustment, and the burst signal on the specific data track is read. The index signal generation timing is adjusted while the time interval Tx between the index signal and the burst signal is measured, and the adjustment is completed when the time interval reaches the specified value To. If the index timings of all the floppy disk devices are adjusted to the specified value To, the compatibility can be maintained with the index signal detection position as the data track start position. Conventionally, the following method has been adopted to make this adjustment. That is, since the index signal is generated by the rotating disk or disk spindle motor and the detector fixed on the floppy disk device with a screw, the fixed detector is usually used to adjust the generation timing. The troublesome method is to move it and screw it in again. Alternatively, if the index signal is input to the delay circuit and the output from the circuit is used as a new index signal, the timing can be adjusted by adjusting the delay amount with a trimmer or the like.

[0003]

[Problems to be solved by the device]

 However, the above-mentioned conventional adjustment method has a problem in the adjustment accuracy and cost because it requires manpower for the adjustment, and further, it has poor reliability because it has a mechanical movable portion. Therefore, an object of the present invention is to provide a floppy disk device having a function of automatically adjusting the timing of an index signal.

[0004]

[Means for Solving the Problems]

 The present invention has been made in order to solve the above-mentioned problems. A variable delay circuit that receives an index signal as an input and is controlled by a delay amount control signal, a burst signal adjusting circuit, and an output of this burst signal adjusting circuit. A nonvolatile memory element for writing a signal is provided, and the delay amount of the variable delay circuit is adjusted by a delay control signal read from the nonvolatile memory element.

[0005]

[Action]

 Just as in the past, just insert the standard disk into the floppy disk drive and read the burst signal from the head to complete the index signal timing adjustment work. That is, when the burst signal is read from the standard disk, a signal corresponding to the delay amount of Tx-To is sent from the burst signal adjusting circuit, stored in the non-volatile storage element, and the adjustment work is completed. In use, when a normal disk is inserted and activated, the delay amount (delay time) of the variable delay circuit is set to Tx-To read from the nonvolatile memory element, and the index signal is set by the variable delay circuit. Corrected to the proper index signal.

[0006]

【Example】

 (Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention in which a rotor 2 is provided by a permanent magnet 3 provided on a rotor 2 of a disk spindle motor 1 and a Hall element 5 fixed to a base 4. One pulse-shaped index signal is generated every one rotation. Since the rotor 2 and the disk 6 are connected in a specific positional relationship, the index signal will be generated at a specific position in the circumferential direction of the disk. The signal is input to the burst signal adjusting circuit 7 via the variable delay circuit 11, but the delay amount before adjustment is zero. When adjusting, mount a standard disk. In this case, the head 8 reads the signal written on the disk 6, but since the disk at the time of adjustment is a standard disk, only the burst signal is read. The read burst signal is input to the burst signal adjusting circuit 7. The burst signal adjusting device 7 measures the time interval Tx between the input index signal and the burst signal, calculates the difference between the specified value To and the digital value, converts the result into a digital amount, and completes the writing adjustment to the EEPROM 9. The EEPROM is an electrically erasable non-volatile memory. Although the adjustment is automatically completed in this way, the normal operation of the floppy disk device will be described. When the power is turned on, the delay amount is read from the EEPROM 9 and set in the variable delay circuit 11. The new index signal output from the variable delay circuit 11 indicates the start position of the data track to the read / write circuit 12, and the compatibility between the floppy disk devices can be maintained.

(Embodiment 2) FIG. 2 shows an embodiment in which the present invention is applied to a floppy disk device equipped with a microprocessor. The microprocessor is an index signal adjusting circuit and a variable delay circuit in the embodiment. Since it has the function of, the present invention can be easily implemented. That is, at the time of adjustment, the microprocessor 14 measures the time interval Tx of the burst signal of the standard disk 6 as an index signal according to the adjustment program 13a, calculates the difference from the specified value To, and converts it into a digital amount, Write the result to EEPRO M9a. During normal operation, the CPU 13 in the microprocessor 14 reads the delay amount from the EEPROM 9a when the power is turned on, delays the input index signal, and outputs it as a new index signal to the read / write circuit 12. Although the index signal generation method is based on the permanent magnet 3 and the Hall element 5 in both embodiments, the present invention is also effective if the method is based on a photo coupler used in a 130 mm floppy disk drive.

[0008]

[Effect of the device]

 As described above, according to the present invention, it is possible to automate the adjustment of the index signal generation timing and supply a highly reliable floppy disk device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of an index signal timing adjusting method according to the present invention.

[Explanation of symbols]

 1 Disk Spindle Motor 2 Rotor 3 Permanent Magnet Piece 4 Base 5 Hall Element 6 Disk 7 Burst Signal Adjustment Circuit 8 Head 9 EEPROM 11 Variable Delay Circuit 12 Read / Write Circuit 13 CPU 14 Microprocessor

Claims (2)

[Scope of utility model registration request] 1. A variable delay circuit for delaying the timing of an index signal by a delay amount, a burst signal adjusting circuit connected to a head, and a non-volatile memory element for writing an output signal of the burst signal adjusting circuit, A floppy disk device characterized in that the delay amount of the variable delay circuit is adjusted by a delay amount control signal read from a non-volatile storage element. 2. The floppy disk device according to claim 1, wherein a variable delay circuit, a burst signal adjusting circuit, and a non-volatile memory element provided in the microprocessor are used.