JPS62293578A - Floppy disk device - Google Patents

Abstract

PURPOSE:To correct the positioning error due to an error of data recording and chucking of a variable length sector form by positioning a magnetic head to an object track by the data in a servo area so as to correct the positioning error. CONSTITUTION:A servo area detector 14 reads a read data signal 12 a to output a servo area detection signal 14a representing that the magnetic head 4 passes through the servo area. An A/D converter 15 starts digital conversion by the arrival of the signal 14a, outputs an A/D conversion end signal 15b at the end of conversion and outputs a digital data 15a to a bus line. A control circuit 24 outputs a strobe signal 16a to a position control device 16 to command the fetch of the data 15a and the control device 16 starts the position correction at the end of fetch to position the magnetic head 4 accurately to the servo track of the object track.

Description

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

[Conventional technology]

Conventional floppy disk drives use oven loop control using a stepping motor to position the magnetic head on the target data track, or position the magnetic head on a servo area provided in a part of each sector on the data track. It adopted a so-called embedded servo system, which follows the closed roof servo system.

[Problem that the invention seeks to solve]

The conventional floppy disk drive mentioned above uses an embedded servo system, and this system provides a servo area in a part of each sector on the data track, so the first problem is that variable-length sector format data cannot be recorded. There are drawbacks. Also, if you try to solve this problem while maintaining the closed loop servo system by providing one servo area per revolution on the data track, the center of rotation of the floppy disk and the floppy disk that occur when the floppy disk is installed A second drawback is that the servo mechanism becomes ineffective against deviations from the center of the data track recorded in the data track, a so-called chucking error. Furthermore, in this case, there is a third drawback in that it is also ineffective against positioning errors caused by the anisotropy of the thermal expansion coefficient of the floppy disk medium.

[Means for solving problems]

A floppy disk device according to the present invention includes a floppy disk comprising at least one servo track having a plurality of first servo areas per revolution and a data track having one second servo area per revolution. , detecting a plurality of first position error amounts based on data from the first servo area read from the magnetic head, and detecting a second position error amount based on data from the second servo area. storage means for storing the first positional error amount; switching means for switching write and read addresses for the storage means in synchronization with the rotation of the floppy disk; After positioning the magnetic head on the target data track based on the second positional error amount, the first positional error amount sequentially read from the storage means is used as a correction amount to set the target data of the magnetic head. and a driving means for controlling the position on the track.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention.

In FIG. 1, 4 is a magnetic head and 5 is a floppy disk.

FIG. 2 is a plan view of the floppy disk of the embodiment shown in FIG.

In FIG. 2, 1 is a servo track, 2. and 2b are data tracks, 31 to 3. , is the servo area.

FIG. 3 is a diagram showing the recording state of the servo area shown in FIG. 2.

In FIG. 3, 3X and 3y are servo patterns.

FIGS. 4(a) and 4(b) are waveform diagrams of output data when the servo pattern of FIG. 3 is read.

FIG. 4(a) shows the change in read voltage when the servo patterns 3X and 3y are read with the magnetic head 4 at position A in FIG. 3, that is, accurately positioned on the track.

FIG. 4(b) shows the servo pattern 3 when the magnetic head 4 is at position B in FIG.
It shows the change in 1 selling voltage when reading X and 3y.

As described above, when there is a positioning error in the magnetic head 4, a difference occurs between the read voltages of the servo patterns 3X and 3y. The positional error of the magnetic head 4 with respect to the track G is detected from changes in read voltages such as the servo patterns 3X and 3y, and the magnetic head is accurately positioned on the track.

Again, in FIG. 1, 10 is an amplifier for amplifying the read voltage, 11 is a differentiator, and 12 is a pulse generator, whose output 12. becomes a signal representing the contents recorded on the floppy disk, and this signal is sent as a read data signal to a host device connected to the floppy disk device.

13 is an envelope signal 13.1 of the output of the amplifier 10. 14 is a servo area detector that reads the read data signal 123 from the pulse generator 12 and detects the servo area; 15 is A that converts the envelope signal 133 from the detector 13 into a digital value; -D converter, which receives the servo area detection signal 148 output from the servo area detector 14 as a digital conversion start signal and receives an A-D conversion end signal 15. which indicates the end of digital conversion. and digital data 153. The signal line that conveys the digital data 15a usually consists of a plurality of signal lines, and the signal on each signal line constitutes a path line representing each digit of a binary number.

16 is analog-digital converted digital data 15. are input, data tracks 2a, 2 . This is a position controller that calculates the positional error of the magnetic head 4 relative to the magnetic head 4 and rotates a stepping motor mechanically connected to the magnetic head 4 by a minute angle so that this positional error is minimized, that is, performs a position correction operation. 16□ is digital data 15. to be input to the position controller 16. is a strobe signal indicating that strobe signal 16. is output, and position controller 16 receives strobe signal 16. The above-mentioned position correction operation is started upon arrival of .

19 receives one step signal for instructing track feeding and a direction signal 19b for instructing the direction of track feeding, that is, the rotational direction of the stepping motor;
This is a track feed control circuit that rotates the stepping motor one track per step pulse. Furthermore, the track feed control circuit 1 receives a signal 24a indicating whether the magnetic head 4 is positioned on the servo track 1 or the data track 21 or 2b, and a signal that prohibits the above-mentioned position correction operation during the track feed operation. 16b. 17 is a motor drive circuit that drives the stepping motor. Reference numeral 18 denotes a stepping motor, and a magnetic head support mechanism is connected to the stepping motor through a booby coupled to its rotating shaft and a steel belt stretched thereon. That is, the magnetic head 4 is driven by the stepping motor 18.
It has a structure that allows it to be moved between tracks by rotation.

20 is an index detector which detects an index hole (not shown in FIG. 2) provided on the floppy disk 5 and generates an index pulse 201. 2
1 is a clock signal 21.1 triggered by an index pulse 203 and synchronized with rotation. This is a clock generator that outputs .

22 is digital data 15. A storage element that stores a write signal 24. to a storage address specified by an address counter. When the digital data 15. remember. 24h is an input/output control signal for the storage element 22, which is the digital data 15.24h from the A-D converter 15. , to the storage element 22 or stored digital data 15. This is a signal that specifies whether to send the signal to the position controller 16.

23 is a clock signal 211. or A-D conversion end signal 1
This is an address counter whose address is updated by the address update signal 24c generated by the 5b and initialized by the index pulse 201.

24 is a control circuit, and FIG. 5 is a detailed block diagram thereof.

25 is a monostable multivibrator that is triggered by the index pulse 20a and outputs a timing pulse 253 of a constant width.

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to FIGS. 6(a) and (b). 6(a) and 6(b) are time charts for explaining the operation of the embodiment of FIG. 1. FIG.

The operation of the floppy disk device shown in FIG. 1 is started by track-feeding the magnetic disk 4 onto the servo track 1 shown in FIG. That is, step signal 1
9. In response to the direction signal 19b, the magnetic radar 4 is step fed to the vicinity of the servo track 1.

During the step feed operation, the above-described position correction operation is prohibited by signal 16I.

Figure 6 (
This will be explained with reference to a).

The signal 24d from the track feed control circuit 19 is at a logic level "" indicating that the servo track 1 is the target track.
It is '1°'.

The index detector 20 detects the time t by detecting the index hole provided on the floppy disk 5 of FIG. An index pulse 203 is output. The address counter 23 is initialized by the index pulse 203, and the monostable multivibrator 25 is initialized by the index pulse 20. A constant width timing pulse triggered by 25. Output.

The servo area detector 14 reads the read data signal 12a to generate a servo area detection signal 14. which indicates that the magnetic head 4 is passing through the servo area. Output.

At time t1, the servo area detection signal 14 is the third
This indicates that the vehicle is passing through the servo pattern 3X shown in the figure, and at time t3, it is indicated that the vehicle is passing through the servo pattern 3y.

The AD converter 15 starts digital conversion of the envelope signal 131 from the wave detector 13 upon arrival of the servo area detection signal 14°. The A/D converter 15 outputs an A/D conversion completion signal 15b at times t2 and t4 when the digital conversion is completed, and at the same time outputs digital data 151 to the pass line.

Control circuit 24 outputs strobe signal 16. at times t2 and t4. , is output to the position controller 16, and the digital data 15. Instruct to import. The position controller 16 accurately positions the magnetic head 4 on the servo track 1 of the target track by starting the above-described position correction operation when the capture is completed.

At time t5, the control circuit 24 sends the A'-D conversion end signal 15. from the A-D converter 15 to the address counter 23. is output as an address update signal 24c that instructs address update.

The address counter 23 updates the address at the rising edge of the address update signal 24C. Furthermore, the control circuit 24
Digital data 153 from converter 15 is stored in storage element 2
A write signal 248 to be stored in 2 is output.

The storage element 22 stores the digital data 151 when the write signal 243 falls. Thereafter, digital data 158 is stored in the storage element 22 in the same manner.

Next, step signal 19. and direction signal 19b
With the arrival of the data track 2., the magnetic head 4 moves to the data track 2. shown in FIG. Regarding the operation after the track is sent to
This will be explained with reference to Figure (b).

Signal 24 from one track feed control circuit. is a logic level ""0" indicating a data track.

The operation from time txt to time t14 is similar to the operation from time t1 to t4 in servo 1-rack 1 described above, and servo area 3. The position correction operation of the magnetic head 4 is performed based on the amount of positional error detected. That is, time t
12 and t14, the control circuit 24 receives the clock signal 21.12 from the clock generator 21. Strobe signal 16. The signal is supplied to the position controller 16 as a signal. Position controller 1
6 is a strobe signal 16. A-D converter 15 at the falling edge of
The digital data 15'3 is taken in from the digital data 15. The above position correction operation is performed by.

After time t15, the control circuit 24 outputs the input/output control signal 24.
b instructs the storage element 22 to output the stored digital data onto the pass line, and A
-D converter 15 is instructed to inhibit output by signal 24e, so at times t-16 and t17, position controller 16 outputs digital data 15. The captured data is data read from the storage element 22, that is, data representing the amount of positional error on the servo track 1.

Thereafter, the above-described position correction operation is similarly performed based on the position error amount on the servo track.

To summarize the above operation, the magnetic head is positioned on the servo track based on the positional error amount obtained from the servo area immediately after the index pulse, and the positional error amount obtained from the subsequent servo area is stored in the storage element.

Next, after positioning the magnetic head on the data track of the target track based on the position error amount obtained from the servo area immediately after the index pulse on the data track,
The magnetic head is positioned based on the positional error amount stored in the storage element.

FIGS. 7(a) and 7(b) are characteristic diagrams showing an example of positional deviation in the servo track of the magnetic head.

That is, FIGS. 7(a) and (b) show the results of the position controller calculating the position error of the magnetic head relative to the servo track from the results of digital conversion of data from each servo area on the servo track, with the horizontal axis as an index. The rotation angle with the pulse as the starting point and the vertical axis as the positional error amount are shown in Fig. 7<a). Figure (b) shows a case where there is a chucking error or anisotropy in the thermal expansion coefficient of the floppy disk medium.

In the characteristic example shown in FIG. 7(b), since the data track also has positional deviation in the same way as the servo track, positioning is performed based on the position error amount obtained from the servo area immediately after the index pulse in the data track. After that, if the position is corrected based on the amount of positional error in the servo area of the servo truck, positioning can be performed on the data track without causing a positioning error.

It goes without saying that a part or all of the main parts constituting the present invention can be constructed by a stored program method using a microcomputer.

〔Effect of the invention〕

As explained above, the floppy disk device of the present invention positions the magnetic head on the target track using data from the servo area immediately after the index pulse of the target track, and uses data from a plurality of servo areas on the subsequent servo track to position the magnetic head on the target track. By correcting the positional error of the magnetic head on the data track, recording and reproducing data in variable length sector format becomes possible, and positioning error caused by chucking error and anisotropy of the thermal expansion coefficient of the floppy disk medium. This has the effect of making it possible to make corrections to minimize .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
FIG. 3 is a plan view of the floppy disk of the embodiment shown in FIG.
) and (b,) are waveform diagrams of output data when reading out the servo pattern shown in FIG. 3, FIG. 5 is a detailed block diagram of the control circuit of the embodiment shown in FIG. b) is the first
A time diagram for explaining the operation of the embodiment shown in FIG. 7 (
a> and (b) are characteristic diagrams showing an example of positional deviation in a servo track of a magnetic head. 1... Servo track, 2. ．． 2b...Data 1~
Lack, 3. ~3o... Servo area, 3. ．． 3.・・・
- Servo pattern, 4... Magnetic head, 5... Floppy disk, 10... Amplifier, 11... Differentiator, 12... Pulse generator, 12. . . . Read data signal, 13 . . . Detector, 13. ...Envelope signal, 1
4... Servo area detector, 143... Servo area detection signal, 15... A-D converter, 15. ...Digital data, 15b...A-D conversion end signal, 16.
...Position controller, 163...Strobe signal, 17.
...Motor drive circuit, 18...Stepping motor, one...Track feed control circuit, 19. ...Step signal, 1 b...Direction signal, 20.
...index detector, 20. . . . index pulse, 21 . . . clock generator, 218 . ...Light signal, 24
b... Input/output control signal, 24c... Address update signal, 25... Monostable multivibrator, 2
5. ...timing pulse. Agent: Patent Attorney ± IEIa', #Banjii / Kokaya 2wJ. ,・]2] M animals υM ■ Separate song circle ■ Plate [II hand 4
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Claims (1)

[Claims] A floppy disk comprising at least one servo track having a plurality of first servo areas per revolution and a data track having one second servo area per revolution;
Detecting a plurality of first position error amounts based on data from the first servo area read from the magnetic head, and detecting a second position error amount based on data from the second servo area. a detection means, a storage means for storing the first positional error amount, a switching means for switching write and read addresses for the storage means in synchronization with the rotation of the floppy disk, and a storage means for storing the first positional error amount from the target data track. After positioning the magnetic head on the target data track based on the positional error amount of 2, the first positional error amount sequentially read from the storage means is used as a correction amount to adjust the magnetic head to the target data track. A floppy disk device comprising: drive means for controlling the upper position of the floppy disk device.