JPS63127472A - Format writer for magnetic disk - Google Patents

Abstract

PURPOSE:To make a disk driving device itself perform the writing-in of a servo signal by providing a specified write data pattern detecting means for a format, and providing a DC erased area detecting means, a servo signal generating means and a high accuracy positioning means, for a read. CONSTITUTION:The output voltage of a head 3 is differential-amplified 7 and is demodulated, and a read data 8 is outputted and monitored, and a written servo pattern is recognized 9. After the recognition, a circuit 10 holds the voltage for a time necessary for A/D converting a head dislocation quantity from the output of the amplifier 7. A dislocation information is fetched in an MCU 13 by this procedure, and a correction quantity is calculated, and the head is driven 6 to a destination position. Under the control of the MCU 13, the circuit 12, at first, detects a gap from the written data at the time of the format, and stops writing to the amplifier 7, and erases the DC. In a next one revolution, it detects the DC erased area through the use of the read data or the head output, and controls a write gate and the information, and performs the writing of the servo pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Applications Conventional Technology Conventionally, this type of flexible magnetic disk drive device is
When trying to increase the capacity (2) It was directly effective to increase the number of tracks arranged on the recording medium, but on the other hand,
As the track pitch became smaller, it was necessary to meet the requirements for precise magnetic head positioning. For this purpose, special information is recorded on the recording medium, and the positional deviation of the magnetic head (
It has been common practice to use so-called servo control technology, which detects off-track (off-track) and automatically causes the magnetic head to follow the correct position.

An example of the above-mentioned conventional flexible magnetic disk device will be outlined with reference to FIG. In FIG. 13, 91 is a flexible magnetic disk, 92 is a data track on which original information is recorded, and 93 and 94 are recording patterns called servo patterns embedded in specific positions of the tracks for detecting head position deviation. , these recording patterns 93 and 94 are arranged so that the center of the trunk is located between the data trunks.

Next, the operation of the above conventional example will be explained. In Figure 13, the magnetic head is located directly above the data track.
The amplitudes of the servo patterns that are reproduced temporally at the same position are equal. However, if the magnetic to rad misalignment occurs in either direction, the amplitude of one servo pattern will be different from the amplitude of the other servo pattern. Furthermore, this difference in amplitude occurs in correspondence with the direction of positional deviation.

As described above, it is possible to know the head position from the amplitude of the servo pattern, and correction to the correct head position is performed.

Problems to be Solved by the Invention However, the above-mentioned conventional magnetic disk drive device, in particular,
A flexible magnetic disk drive device has a problem in that a dedicated magnetic recording medium on which servo signals are written is required because the drive device is not equipped with a means for writing servo signals onto a magnetic recording medium.

The present invention solves these conventional problems,
The object of this invention is to realize an excellent flexible disk drive device in which servo signals can be written by the drive device itself.

Means for Solving the Problems In order to achieve the above object, the present invention provides a specific write data pattern detection means at the time of formatting, and a DC ease area detection means, servo signal generation means, and high precision spatula positioning means at the time of reading. , the servo signal can be written to the magnetic recording medium by the flexible disk drive itself.

Effects The present invention has the following effects due to the above configuration. That is, during formatting, a specific pattern is detected from the ride data, and an area where no information is recorded, ie, a DC erase area, is created at a specific position in the format. Next, the head actuator moves the head to a predetermined write position of the servo signal, detects the DC erase area on the magnetic recording medium, and uses the servo signal generating means to specify the servo signal on the magnetic recording medium. Write to the location. By repeating the above procedure, servo signals can be written on the magnetic recording medium.

Embodiment FIG. 1 shows the configuration of an embodiment of the present invention. 1
2 is a magnetic recording medium, and 2 is a drive motor that rotates the recording medium 1 at a constant rotation speed.

3 is a head, which is fixed on a carriage 4 and moved by an actuator 5. 6 is a drive circuit for the actuator 5, and this drive circuit 6 receives head position information from a microcomputer unit 13 (hereinafter referred to as MCTJ) and moves the head. Further, although not shown in FIG. 1, in order to perform highly accurate head positioning, there is a means for detecting the head position using an encoder or the like and transmitting the head position information to the MCU 13.

7 is an amplifier that differentially amplifies the output voltage of the head, and 8 is a pulse detector that demodulates the head output amplified by the amplifier 7 into digital data. Note that the pulses demodulated by this pulse detector 8 are referred to as read data.

On the other hand, the servo pattern detector 9 monitors read data and recognizes the servo pattern written on the magnetic recording medium.

When the servo pattern detector 9 recognizes the servo pattern, it operates a sample hold circuit 10 and an AD co-converter 11 to capture head position deviation information from the servo pattern reproduction signal. At this time, the sample and hold circuit 1o is a means for holding the output voltage of the amplifier 7 for a time necessary for the AD converter 11 to quantize the amount of head position deviation into digital data from the output voltage of the amplifier 7.

The AD converter 11 is a means for converting the analog signal output from the amplifier 7 into digital data.

Through the above procedure, the MCU 13 transfers the head position deviation information to A.
Import from the D converter 11. MCtJ13 is based on the amount of head position deviation taken in from the AD converter 11.
By calculating the head position correction amount and outputting a head position control signal to the drive circuit 6, the head movement to the target position is realized. Reference numeral 12 denotes a servo pattern writing circuit for writing a servo pattern onto a flexible disk and a magnetic recording medium by the driving device itself.The details will be described later, but an outline will be given below. That is, first, gap 3 is detected from the write data during formatting, and immediately thereafter, the output of the write data to the amplifier 7 is stopped, thereby performing DC erasing. A servo pattern is written in the next rotation, and this operation detects the DC erase area using the read data from the pulse detector 8 or the head output, or both of the above, and controls the write gate and write data to the amplifier 7. and write the servo pattern. The servo pattern writing circuit 12 is controlled by the MCTJ13.
Managed by.

FIG. 2 shows the configuration of the servo pattern writing circuit. A multiplexer 20 switches between write data from the host computer and write data for servo patterns. The other multiplexer 21 switches between the write gate from the host computer and the write gate for the servo pattern. 22 is a servo pattern generation circuit, and a timing control circuit 24 outputs write data for the servo pattern and selects the servo pattern. IAM, DAN・GAP
The detection circuit 23 detects IA from the write data during formant.
Detection of specific patterns such as M (index address mark), DAM (data address mark), and GAP (gap) is performed under the control of the timing control circuit 24. The timing control circuit 24 controls DC erase, DC erase detection, servo pattern output, write data, write gate switching, etc. based on signals from the MCU 13. 25 is a DC erase area detection circuit;
DC erase is detected under the control of 24 using the read data from the pulse detector 8 shown in the figure or the head output from the amplifier 7 shown in FIG.

FIG. 3 is a flowchart showing the servo pattern write sequence. First, the write gate is turned on (step 52) immediately after the index pulse (step 51).
This occurs only during formatting, so the computer recognizes that it is a formatting operation and stops outputting the index signal to the host (step 5).
3). As a result, the host computer enters a wait state in which the index pulse is output. DAM (step 54) until the next index signal is detected.
.

When GAP is detected in this order (step 55), write data is stopped internally and DC erase is performed (step 56).
), and if detected in any other order, DC erase is not performed. This sequence is repeated for n sectors, which are all sectors of one track. When the index is detected (step 57), the head is moved 50% off-track from the track center (step 58), and waits for the next index to be detected (step 59).
Once detected, a DC erase area is detected (step 60).

When the index is detected, the servo signal including DC erase is written (step 61). This sequence is performed for n sectors until the next index is detected (step 62). When this index is detected, the index is written to the host computer. Output a signal (step 64)
At the same time (step 65 of returning the two heads to their original positions), the index and write gate are monitored again. However, when a servo pattern write error occurs, the third
Redo the servo pattern write from Figure 1 (Step 6)
3).

When the host computer (FDC) detects the index, it stops write data and write gate output, outputs a step signal to the flexible disk drive to raise the cylinder position by one position, and then outputs a step signal to the flexible disk drive for a specified period of time until the head comes to rest. When the index is detected after waiting for a period of time, the write gate and write data are output again, and the above sequence is repeated, so that the servo pattern including the DC erase area is embedded in GAP 3. However, when formatting n tracks corresponding to the innermost track, formatting is performed up to track n+1, and formatting is performed from the outer track to the inner track.

FIG. 4 shows the timing of each signal in one embodiment of the present invention. 30 is an index signal inside the drive device, and the index signal to the host computer is gated by an index delay signal 34. On the other hand, normally, during formatting, the host computer monitors the low level of the index pulse, and controls the write data and write gate immediately after this index pulse becomes low level. Therefore, if the index signal is at a low level and the write gate is at a low level, it can be predicted that formatting will be performed during one round immediately after that, and the formatting signal 33 can be generated within the drive device. The format signal 33 is sent to the microprocessor (MCU).
), and when the format signal is detected, the index delay signal 34 is output and the index pulse 31 to the host computer is stopped. As a result, after writing one track's worth of format data, the host computer continues to send the GAP 4 signal, which is the final block of one track's worth of formant data, until the next index is detected. On the other hand, M of the drive device
The CTJ 13 operates the servo pattern write circuit 12 shown in FIG. The DAM-1-GAP detection signal 35 is a GA block in which the DAM and GAP detection circuit 23 shown in FIG.
This is a signal that is generated when the write pattern P3 is detected. At the falling edge of this signal 35, the DC erase timer 36 is activated for the time necessary to embed the servo pattern including the DC erase area in a predetermined area, which will be described later. activated. Write data 42 from the host computer is DC
It is masked by the erase timer 36, and as a result,
A part of GAP 3 of the pattern written on the recording medium is DC erased. As a result, a portion of GAP 3, which is the tail end of all sectors in one track, can be DC erased. Next, when the MCU 13 of the drive device detects the index signal 30 of the second rotation inside the drive device, the MCU 13 detects the index signal 30 of the second rotation inside the drive device.
The head is driven off-track to the outer circumference of 50% of the track pitch and waits for the next index signal. In this case, it takes time for one revolution to bring the head off-track, but this time can also be saved. That is, when performing the DC erase of GAP 3 described above, M
If the CtJ13 manages the index period, it is possible to move the head immediately after DC erasing the final sector, and the servo pattern including the DC erase area can be erased immediately after the next index signal 30 is detected. If you write the servo pattern, you can eliminate the waiting time for one rotation, and you can write the servo pattern in the format that does not write a normal servo pattern plus the waiting time for one rotation. You can save money.

Next, after the MCU 13 finishes moving the head and detects the index signal 30, it activates the DC erase detection circuit. Reference numeral 37 is a DC erase detection signal of the DC erase detection circuit (it becomes low level at the moment when the DC erased area is detected during the first round as described above. On the other hand, 38
is an erase gate signal, and this signal 38 prevents the above-mentioned erroneous detection of the DC erase area.The internal timer of the MCU 13 measures the timing based on the index pulse of the first DC erase performed in the same month. Based on the results, the DC erase detection signal is gated. That is, the servo pattern write signal 39 is generated by ANDing the DC erase detection signal 37 and the erase gate signal 38. As a result, erroneous detection of the DC erased area due to unexpected omission of the reproduced signal is prevented.

As described above, the servo pattern write signal 39 is turned on only when the DC erase detection signal 37 falls while the erase gate signal 38 is at a low level.
At the same time, the servo pattern generation circuit 22 also operates synchronously. Reference numeral 40 indicates an operation signal for this servo pattern generation circuit 22, which is activated when the servo pattern write signal 39 is at a low level. By the above procedure, the write gate signal to the recording amplifier of the head becomes 41. That is, the first 1
In the same month, when GAP 3 DC erase is performed, it is opened during the period of GA and P3 at the end of each sector until just before the head is moved or until the next index signal is detected. The head moves and remains closed until the next index signal is detected, or DC after the index signal.
When detecting the erase area and embedding the servo pattern including the DC erase area, all sectors of one track are
Open for all sectors. 42 is write data that enters the recording amplifier of the head, and GAP 3 of n sectors.
The data from which part of is removed is applied and finally GAP 4
data is applied. Data is stopped when the head is moved, and a specific servo pattern is applied as write data only when writing a servo pattern after the next internal index signal. YMCU finishes writing the servo pattern
waits for the internal index signal 30, detects this signal, returns the index delay signal 34, inputs the external index signal 31 to the host computer, stops write data from the host and output of the write gate, and formats. 33 returns to normal. Next, the host computer issues a step signal in order to move the track, waits for a certain period of time for settling, and then detects the index signal 31 and activates the write gate 32.
To open the track, the format signal 33 becomes low level, and the MCU repeats the sequence of writing the servo pattern again, thereby writing the servo pattern for each track. However, when a magnetic recording medium (hereinafter referred to as the medium) is inserted into the drive device, the MCU determines whether it is a conventional medium or a medium used in the present invention (hereinafter referred to as the high recording capacity medium), and then When using capacity media, check whether there is a servo pattern, and if there is no servo pattern,
In the case of unformatted media, it is necessary to perform DC erase processing over the entire circumference of 11 tracks one track further outside the outermost track. This operation is
This process is performed from the insertion of the media until the drive device outputs a ready signal indicating that the drive device is available for use to the host computer.

The time required to perform formatting including writing of servo patterns in the first embodiment of the present invention is as follows.

As an example, a case will be described below in which both sides rOJ and rlJ are used as media, and 160 cylinders are used. Here, as described above, it is assumed that the head movement is performed immediately after the last sector of format data writing in the first rotation by the index cycle management of the MCU internal timer. If the conventional example for comparison is a drive device with 80 cylinders on both sides, the head will move between tracks 79 times.

One rotational waiting time is required for one movement of the head between tracks, and if each head placed on both sides of the media requires one rotational waiting time even if the head is switched (=), then at track zero, the head Due to the waiting time of one rotation only for switching, it takes time for three rotations, and then from 1 to 79
Since it takes a total of 4 rotations to reach the cylinder, 2 rotations for moving and switching between ``F'' and ``D'' and 2 rotations for formatting both sides of the media, the rotation speed of the media drive motor is 30 rpm.
In the conventional example, format time = 200 [mS/1 rotation IX (3+
4X79) [Rotation] "" 1 minute 06 seconds out of 63800ms.

- In the strength tree embodiment, the media is single-sided format; because the waiting time for one rotation increases, formatting time = 200 [[mS/1 rotation]]
[: 3+2+(4+2) mowing 59] [rotation] = 3 minutes 12 seconds out of 191800ms.

In this embodiment, the stop of DC erase was set using a timer as described above, but in the second embodiment,
A method of stopping DC erase by detecting a specific pattern (5YNC pattern) of write data arranged at the beginning of each sector.As a third embodiment, GAP 3 is stopped based on format data applied to the drive device. There are two examples in which the length of the DC erase is measured using an internal timer of the MCU, and the optimum DC erase time corresponding to the format is set.

In the second embodiment above, 5YNC written at the beginning of the sector
The first few bits of the pattern may be missing, which may adversely affect the data demodulation operation. In the third embodiment, the first few bits of the pattern are Therefore, there is a drawback that the optimum DC erase length cannot be applied to the first one track.

Therefore, it is necessary to carry out optimal application while taking the above points into consideration.

In the first embodiment, the DC erase area is detected not only by monitoring the read data pulse interval but also by using a gate signal for detecting the DC erase area by the MCU, thereby preventing erroneous detection. Since this false detection depends on the writing quality of the medium and the degree of mixing of external noise, various applications are possible depending on the content.

That is, the second embodiment is a simple method in which only the pulse interval of read data is monitored.

The third embodiment is a method in which the output of the head amplifier is applied to a comparator and monitoring is performed by detecting a drop in the head output.

The fourth embodiment is the second embodiment. Or D described in the third embodiment
The DC erase tie mini”j by the MCU described in the first actual M example is applied to the C erase area detection signal.
This method uses gate output to erase.

As shown in FIG. 5, the servo pattern written on the media in the above embodiment is set at GAP 3 of each sector at an intermediate position between adjacent track centers (typically, 50% off-track from the track center to the inner and outer peripheries). Position) (=Write. Adjacent servo patterns are written alternately in time, resulting in a staggered arrangement.

In the fifth embodiment, when performing DC erase of GAP 3, as shown in FIG.
Data of a specific frequency, such as 1.5T, is written alternately on odd-numbered tracks, and the writing pattern of this specific frequency is reliably detected when writing servo marks, thereby preventing erroneous detection of the DC erase area. It is.

As can be easily inferred, the fifth embodiment described above is also possible by writing a specific pattern only on even-numbered tracks or odd-numbered tracks, which will be described below.

In the sixth embodiment, as shown in FIG. 11, a specific pattern is written in only even-numbered or odd-numbered specific tracks, and then DC erase is performed. The writing position of the servo pattern is detected from this pattern and the servo pattern is written.

The seventh embodiment adds the DC erase area detection method described in the second or third embodiment to the sixth embodiment, and
A method to reduce false detection of erased areas.

The eighth embodiment performs the specific pattern detection and DC erase detection described in the sixth embodiment, and detects the specific pattern or detects both the specific pattern and the DC erase area as in the first embodiment. In this method, the gate output is performed from the MCU +2 to further reduce erroneous detection of DC erase.

In the first embodiment, GAP 3 at the end of each sector
However, as a ninth embodiment, as shown in FIG.
It is also effective to write a servo pattern within the P1 area. In the first embodiment, the interval from the last sector until the first sector appears again is generally longer than the interval between sectors 1 to 7, and the head position that occurs due to eccentricity of the medium, etc. Misalignment tends to become larger due to different accumulation. However, as shown in this example, the above GA
By embedding a servo mark in P1, it is possible to correct the head position in the leading region of the track, and it is possible to reduce the head position deviation when the first sector is reached.

Furthermore, as will be explained below with reference to FIG. 8 as a tenth embodiment, depending on the sector configuration within one track, GAP 4, which is the end of the track, becomes longer, and the distance from the last sector to the first sector or the beginning of the track becomes longer. IA
The period until M is longer, and the head position deviation is caused by this gap
GAP accumulated in four areas and described in the ninth embodiment above
Correction in one area may be inappropriate. To prevent this, it is effective to write servo patterns in the GAP 4 area at approximately the same intervals as normal sector intervals. The writing timing of the servo pattern of GAP 4 mentioned above is given at an appropriate constant interval under the control of the MCU of the drive device, and the servo pattern can be written in the same way as a normal sector by using this MC[J. It is. Note that in the tenth embodiment, the GAP
Although it is possible to write a plurality of servo patterns in No. 4, another advantage arises in this case. This will be discussed below.

The eleventh embodiment is similar to the tenth embodiment described above.
The difference is that the servo pattern is written as densely as possible at the highest frequency that the head actuator can sufficiently follow.

This is illustrated in FIG. The timing for writing the servo pattern is given by MCIJ. In the case of the above servo pattern, if the sequence is to read/write the last sector of any track and then immediately move the track (for example, copying data on a medium), read/write the last sector and then move the track between the tracks of the head. Immediately after a seek, the servo pattern appears densely and the sampling frequency for the amount of head position deviation becomes high, so the head position can be corrected at high speed, and when reaching the first sector (sector 1) of the next rotation. Since the head position deviation can be made sufficiently small, there is an advantage that the first sector can be read and written immediately. As a result, the rotational waiting time is eliminated and the throughput of the system is improved, which is an advantage in use.

The twelfth embodiment writes a servo pattern according to the sequence shown in FIG. Writing of a servo pattern by off-track to the inner circumferential side is also performed when writing a format for one track. In the above embodiment, one rotation (or two rotations) is required to write the servo pattern on the inner circumferential side.
For example, in order to format a 160-cylinder, double-sided media, 360 rotations = 360×2.
00mS (at 360 RPM) - # - The formatting time will increase by 1 minute 20 seconds, but even if you format only one track, the servo patterns on the inner and outer circumferential sides will be written, so you can write them on any track in any order. It has the advantage of being able to be formatted.

In the above embodiment, an example is described for a flexible disk drive drive device, but it can be similarly implemented in a fixed disk drive device that uses an index or sector servo method in which a servo pattern is written on the same surface as the DATA recording surface. It is possible.

This embodiment has the following advantages.

(1) Since self-servo writing is possible, ■ A dedicated servo writing device is not required, so media availability is good and maintenance is easy.

■Currently, only fixed sector media such as 15 sectors and 26 sectors are available, but the present invention can also accommodate formats with a variable number of sectors that match the system configuration, improving system flexibility.

■ The system access method allows embedding of servo patterns that improve access speed, improving system throughput and reliability.

(2) DC of GAP 3 as shown in Figure 10
Since the area before and after the servo pattern is DC erased when erasing and writing the servo pattern, unnecessary unerased noise around the servo pattern can be wiped out.
The time required for formatting including writing of the I-servo pattern, which eliminates the need for DC erasing the entire surface of the medium, can be minimized. As a result, even if formatting including writing of servo patterns is performed on, for example, a 160-cylinder, one-sided media, it takes at most three times the formatting time of a conventional 80-cylinder, one-sided media. On the other hand, when DC erasing is performed on the entire surface of the media, depending on the relationship between the track pitch and the read/write track width of the head (there is a risk of unerased areas being generated), it is necessary to It is also necessary to DC erase the position. Therefore, for example, in the case of 160 cylinders, DC erase will be performed on both sides of the media of 320 cylinders, and DC erase time = 200 [mS/1 rotation IX ( 3+
4X320) I11111'a = 4 minutes 28 seconds in 256,600 m5 Format time = 3 minutes 12 seconds + Erase = 7 minutes 40
2 seconds, that is, 7 times as long as a normal formant (:), which causes great inconvenience to the user.

Effects of the Invention As is clear from the above embodiments, the present invention uses a DC erase detection circuit to detect a specific pattern during formatting, sets a DC erase area at this specific position, and servos the magnetic head using a head actuator. The magnetic disk drive moves to a predetermined writing position, detects the DC erase area using the servo pattern generation circuit, and writes the servo signal to a specific position on the magnetic disk, so the magnetic disk device itself can write the servo signal. It has this effect.

[Brief explanation of the drawing]

is a schematic block diagram of the servo pattern write circuit, FIG. 3 is a schematic flowchart of self-servo pattern writing, FIG. 4 is a timing chart of each signal during self-servo pattern writing, and FIG. 5 is a diagram of the first to fourth embodiments. FIG. 6 is a schematic diagram of a format including servo patterns in the fifth embodiment. FIG. 7 is a schematic diagram of a format including servo patterns in the ninth embodiment. 10 Examples (=
9 is a schematic diagram of a format including a servo pattern in the 11th embodiment, FIG. 10 is a state diagram of DC erase around the servo mark, and FIG. 12 is a flowchart showing the self-servo write sequence in the twelfth embodiment, and FIG. 13 is a diagram of a conventional servo pattern. DESCRIPTION OF SYMBOLS 1... Magnetic recording medium (magnetic disk), 2... Drive motor, 3... Head, 4... Carriage, 5
... Actuator, 6... Drive circuit, 7... Amplifier, 8... Pulse detector, 9... Servo pattern detector, 10... Sample hold circuit, 11... AD converter, 12... ...Servo pattern writing circuit, 13...Mα input 14...Interface. Name of agent: Patent attorney Toshio Nakao (3rd person)
Figure 4 Figure 10

Claims (1)

[Claims] A DC erase detection circuit that detects a specific pattern from write data from a host computer and sets a DC erase area at a specific position in the format during formatting, which initializes the recording format before recording on a magnetic disk, and a magnetic head. a magnetic head actuator that moves the servo signal to a predetermined writing position of the servo signal; and a servo pattern generation circuit that detects the DC erase area on the magnetic disk and writes the servo signal to a specific position on the magnetic disk. Disc format writing device.