JPH01237987A - Disk device control system - 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 [Field of Industrial Application] The present invention relates to a control method for a disk device, and particularly to a control method for a floppy disk device that uses a sector servo method as a tracking servo.

1. Prior Art 1 In a floppy disk device, a recording medium is divided into concentric units called tracks and managed. Furthermore, l
Tracks are managed by dividing them into multiple units called sectors. Data is recorded in units of this sector.
The point at which an index pulse, which is output once every revolution of the recording medium, is detected is set as the start position of a track, and the period until the first index pulse is output is divided into a plurality of sectors. The following methods are known as specific means for dividing one track into a plurality of sectors and methods for detecting the start position of a sector.

The first sector start position detection method is called a hard sector method. The hard sector system is described in Kaiji Takahashi, Latest Floppy Disk Devices and Their Application Know-how, JCQ Publishing Co., Ltd. (1982), p. 224. A recording medium used in a hard sector type floppy disk device is provided with a plurality of sector holes on the same circumference as an index hole for generating index pulses. By detecting a sector hole, the position of the detected sector pulse is set as the sector start position.As shown in FIG.
An index hole 202 and the same number of sector holes 203 as the number of sectors per 1 track are provided on the inner circumferential side of 01. As shown in FIG. 2(b), the recording medium 20
When 1 rotates, one shot per rotation, index hole 2
02 is detected. By index pulse 204
is output. Further, by detecting the sector hole 203, a sector pulse 205 is output. disk·
Sector pulse 205 as shown in format 206
The period between pulses is defined as one sector. To find the target sector, index pulse 2
04 is detected, the number of sector pulses 205 is counted. For example, the starting position of sector 2 is the position where the second sector pulse 205 is output.

The second sector start position detection method is called a soft sector method, which is currently widely used in floppy disk devices and other small hard disk devices. This method is described in Chapter 5 [Disks and Disc Format] pages 91 to 100 of the above-mentioned document. This soft sector method will be explained with reference to FIG. The interval between the index pulses 207 is defined as one track.

As shown in the disc format 208, a first gap 209 is placed at the start position of the track. This first
The gap 209 is for absorbing an error in the detection position of the index pulse 207.

Following the first gap 209, the first sector 210 to the nth
Sectors up to sector 211 are arranged. A fourth gap 212 is located at the end of the track. One sector consists of an ID field 213, a second gap 214, a data field 215, and a third gap 216. The ID field 213 is an area for recording sector attributes such as track number and sector number. The second gap 214 is for absorbing the switching time from reading to writing. data field 2
15 is an area where the user records data. The third gap 216 is for absorbing deviations in the writing end position of the data field 215 due to rotational fluctuations of the recording medium or the like. When recording data on a recording medium, read the ID field 213, confirm that it is the target sector based on the attribute information, and then write the following data field 21.
6. When reading data, the ID field 213 is read, and after confirming that it is the target sector, the data recorded in the following data field 215 is read. In the soft sector method, the size of the l sector, and in fact the size of the data field, can be freely set.

The third sector start position detection method is described in B Kei Electronics 1987.8.1 Ofno, 4271 No. 149 a.
to page 165 [2-inch floppy disk,
This method is used in the 2-inch floppy disk device described in ``Using Video Floppies to Achieve High Speed.'' As shown in FIG. 12, the distance between two adjacent index pulses 217 is defined as one track. As shown in the disk format 218, an index signal 219 is recorded at the track start position, followed by a gap 220° and a first sector 221, and thereafter gaps and sectors are recorded alternately at the beginning position of each sector. is determined by the time from the index signal 219 or the rotation angle of the recording medium. 1st sex 22
1 is defined as 71 hours after the end -r position of the index signal 219', second sector 222 is defined as T2 hours after the end position of the index signal 219, and so on.

A gap between each sector is provided to absorb deviations in the detection position of the index signal 219, etc.

The three methods described above are known as methods for dividing one track into a plurality of sectors in a floppy disk device or the like.

In recent years, the capacity of floppy disk devices has been increased by improving linear recording density and track density. When trying to increase track density beyond a certain level, it becomes necessary to employ tracking servo in order to reduce the positioning error of the magnetic head for recording and reproducing data with respect to the target track. Latest Magnetic Recording Technology and Equipment/Apparatus”
Latest Magnetic Recording Technology and Devices/Equipment Editorial Committee Chapter 1 “ω
As stated in ``Disk Device J, 4.4r Head Positioning Mechanism and Control'', tracking servo systems can be broadly divided into data recording systems, in which servo signals used for tracking servo are recorded on the same recording surface as data recording. There are a surface servo method, a servo surface servo method in which a servo signal used for tracking servo is recorded on a recording surface exclusively for servo signals, and a method that uses a combination of these methods. In a floppy disk device, there are only two recording surfaces on both sides of the recording medium, so if a servo surface servo method or a combined method of a data surface servo method and a servo surface servo method is adopted, the storage capacity will be reduced by half.・For that reason, a data surface servo method is adopted. Data surface servo systems include index servo systems, deep recording servo systems, sector servo systems, and the like.

The index servo method is disclosed in Japanese Patent Application Laid-Open No. 57-86910.
As disclosed in the above issue, this is a method in which a servo signal for track positioning is recorded at one location on a track. 1st
As shown in the disc format 305 in FIG. 3(b), the end of an l track defined by two adjacent index pulses 304 obtained by detecting the index hole 302 (FIG. 3(a)) A servo signal 306 is recorded in . A feature of this method is its high compatibility with conventional devices that do not use tracking servo.

By slowing down the rotation speed of the device using this method so that the time T3 excluding the servo signal 306 is equal to the time of one track, that is, the time of one rotation, of the conventional device that does not use tracking servo, This maintains compatibility with devices that do not use tracking servos. However, a servo signal can be obtained only at the position shown in the servo signal area 303 of the recording medium 301, that is, only at one position per one rotation of the recording medium 301. Therefore, it is only possible to make the magnetic head follow the average radius of the track position, and it is not possible to significantly improve the track density.

The deep recording servo system is described in IEEE TRANSACTON on Magnetics, MNG 17, No. 6 (1981), pp. 2735 to 2738 (IEEE TRANSACTTON).
S 0NIGNETIC: S, VOL, MAG-17,
No, 6. N0VE&4BER1981pp2735-
As discussed in No. 27381, this is a method in which a servo signal for track positioning is recorded in the deep layer of the recording medium, and data is recorded in the surface layer. Figure 14 fat
, fb), servo signals 310, 31], , 312 are recorded in the deep layer 309 of the recording medium.

Data 313.degree. 314 is recorded on the surface layer portion 308 of the recording medium while performing track positioning using these servo signals. The characteristics of this method are that since the servo signal is recorded in the deep layer, the disk format of the data recorded in the surface layer can be freely determined, and that the servo signal for track positioning can be obtained continuously over the entire circumference of the track. It is possible to handle high track density. However, in order to read the servo signal and data at the same time, it is necessary to separate each signal and to use a recording method that does not interfere with each other.

The sector servo system is a system in which a servo signal for track positioning is recorded between sectors, as described in the above-mentioned "Latest Magnetic Recording Technology, Apparatus, and Apparatus." As shown in FIG. 15 fal, (bl), the interval between two pulses of the index pulse 318 output by detecting the index hole 316 is defined as one track, and as shown in the disk format 319, the servo control is applied between sectors. A signal is recorded. That is, a servo signal is recorded between each sector, such as a servo signal 322 between the first sector 321 and the second sector 323. The number of sectors is the same as the number of sectors per revolution of the recording medium 315. The servo signals 320, 322, etc. are recorded.The feature of this method is that since multiple servo signals 317 are measured per revolution, it is possible to correspond to a higher track density than the index servo method described above. be.

A soft sector type floppy disk device that uses this sector servo method as a means of achieving high track density is described in the Institute of Electronics and Communication Engineers Technical Research Report 14R86-36f.
(October 1986).

[Problems to be Solved by the Invention] The sector start position detection method and the tracking servo method include the following.

Therefore, each of the above methods will be examined from the viewpoint of suitability for a large-capacity, high-reliability floppy disk device.

First, let's consider the tracking servo method. With the index servo method (Fig. 13), the track density can be improved by about twice that of a conventional device that does not use a tracking servo. It is necessary to adopt a method.

Next, the deep recording servo method (Figure 14) is a modulation method used in conventional floppy disk drives to avoid interference between data recorded on the surface layer and servo signals recorded on the deep layer. A serious problem arises in that the MFM modulation method and the 2-7 modulation method cannot be used.

In this way, the sector servo method (FIG. 15) remains as the tracking servo method. The sector servo method does not have the problem of track density in the index servo method and the problem of the modulation method in the deep recording servo method.

Next, a sector start position detection method will be considered.

First, in the hard sector method (FIG. 1O), there is no need to record an information area related to sector start position detection on the data surface L, so it can be said to be a desirable method for increasing capacity. However, since current floppy disk devices use the soft sector method, only floppy disk controllers (FDCI LSIs) that are compatible with the soft sector method have been put into practical use. Furthermore, in the case of the hard sector method, new problems arise such as the need to supply recording media with sector holes at positions corresponding to the respective sector sizes due to the difference in sector size. Other than this method, the soft sector method (FIG. 11) or the 2-inch floppy disk method (FIG. 12) remains to be considered.

A case will be considered in which the sector servo method is adopted as the tracking servo method and the 2-inch floppy disk method is adopted as the sector position detection method. in this case,
Reliability in the servo signal area becomes a problem. As mentioned above, in the case of the sector servo method, servo signals are recorded between sectors. Further, in the 2-inch floppy disk sector position detection method, the position of the sector is defined by the time distance or rotation angle from index No. 18 recorded near the beginning of the track. Therefore, the important point is that it must not be affected by writing in adjacent sectors. In other words, when data is written to adjacent sectors, the servo signal area must not be destroyed due to the misalignment.From this point of view, the sector position detection method used in 2-inch floppy disk drives has been replaced with the sector servo method tracking servo. If adopted in a floppy disk device that uses , the gap area between sectors will be doubled, that is, before and after the servo signal, and although the reduction in storage capacity can be suppressed by eliminating the need for an ID field, this gap The new storage capacity will be reduced depending on the area.

Therefore, it is conceivable that a sector servo method is ultimately adopted as the tracking servo method, and a soft sector method (FIG. 11) is adopted as the sector start position detection method. However, even in this case, there is a problem in that each sector requires 10 fields and a gap area is required between the ID field and the data field, resulting in a reduction in storage capacity by this amount.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a floppy disk that realizes a sector start position detection method that can reduce the decrease in memory capacity in a floppy disk device that employs a sector servo method as a tracking servo. The objective is to provide a control method for the device.

[Means for Solving the Problems 1] In order to achieve the above object, the present invention provides a method in which an l track is divided into a plurality of sectors, and data is recorded in units of sectors.
A control method for a disk device in which playback is performed and track positioning is performed using servo signals recorded between sectors, the method counting the number of detected servo signals from a track start position, and counting the number of detected servo signals from a track start position. The feature is that the target sector is recognized based on the count value.

In this case, each sector does not require 10 information, but 10
When adding information, when writing data to the sector, detect the sector immediately before the target sector by counting the number of detected servo signals, and after confirming the ID information read from the sector immediately before, It is desirable that the data be written to the target sector together with ID information of the sector.

The present invention also provides a disk device in which a track is divided into a plurality of sectors, data is recorded and reproduced in each sector, and track positioning is performed by a servo signal recorded between sectors. Servo signal detection means for detecting the servo signal; Servo signal counting means for counting the servo signals detected by the detection means; Target sector number setting means for setting the number of the target sector; The present invention is characterized in that it comprises a comparing means for comparing a set value and the counting result of the counting means, and the starting position of the target sector is recognized based on a matching output of the comparing means.

In this case, for example, by providing an end position detection means for detecting the end point of the servo signal, the end position of the servo signal can be set as the start position of the target sector in accordance with the matching output of the comparison means. desirable.

Furthermore, a servo signal detection position predicting means for predicting the position where the servo signal is detected may be provided, and counting by the counting means may be controlled based on the output of the hands FΩ. For example, when the servo signal is not detected at a position predicted by the prediction means, the counting means is stepped, and when the servo signal is detected at a position other than the predicted position, the counting means is stepped. A pseudo servo signal detecting means is provided which does not cause the counting means to advance, or a servo signal interpolation means is provided which forcibly causes the counting means to advance when the servo signal is not detected at the position predicted by the predicting means.

1 Effect 1 In the control system of the floppy disk device of the present invention, a sector servo system is used as the tracking servo. As a result, multiple position error signals (1
This makes it possible to handle high track densities.

Further, in the control method of the floppy disk device of the present invention, the target sector is detected by counting the number of detected servo signals recorded between sectors. The servo signal detection means detects a servo signal from a signal read from the recording medium. The servo f8 counting means is timed to zero by an index pulse detected once every revolution of the recording medium. When a servo signal is detected by the servo signal detection means, the servo signal counter Ω counts the number of detected servo signals.The disc format of the recording medium is to sequentially start the servo signal, the first sector, and the first sector from the start position of the track. Servo signals and sectors are arranged alternately, such as a servo signal, a second sector, and a servo signal.Therefore, by counting the number of servo signals detected by the servo signal counting means, it is possible to calculate the number of servo signals in each sector. It becomes possible to detect the immediately preceding servo signal.The above control detects the servo signal immediately preceding the target sector.Furthermore, the servo signal end position detection means detects the end position of the servo signal.Start of the target sector The position is the end position of the servo signal immediately before the target sector.The start position of the first sector is the end position of the first servo signal, and the start position of the second sector is the end position of the second servo signal.In this method According to the method, the ending position of the servo signal is the starting position of the sector, so there is no need for a gap area between the servo signal area and the sector.The starting position of the sector is based on the number of detected servo signals after the index signal is detected. Since the ID field is detected in the h sector, an ID field is not required in the h sector.Therefore, it is possible to reduce the decrease in the memory capacity.

In a recording medium used in a floppy disk device, part of the recorded contents may become unreadable due to scratches or the like. In the above method, if the area where the servo signal is recorded is damaged and the servo signal cannot be read, there is a possibility that the sector start position will be detected incorrectly. For example, if the servo signal immediately before the second sector becomes undetectable, the third sector will be detected as the second sector. To avoid this, a servo signal detection position prediction means is used. If a servo signal is detected at a certain point in time, it is possible to predict the position or time at which the servo signal will be detected first.

Since a sector is placed between the servo signals, the time between the servo signals is l Sera 2
It's a minute's time. Therefore, it can be determined that the servo signal detected near the position predicted by the servo signal detection position prediction means is a regular servo signal. On the other hand, if the servo signal is not detected near the predetermined position IZ, it is considered that servo No. 18 has become undetectable due to scratches or the like. Therefore, if a servo signal is not detected near the position predicted by the servo signal detection position prediction means, the count of the servo signal counting means is automatically incremented by 1, thereby preventing the target sector detection error as described above. . Conversely, if a servo signal is detected at a position where a servo signal should not be detected, part of the data recorded in the sector may be detected as a servo signal due to an error in reading data inside the sector. considered to be a thing. If this is counted as a servo signal by the servo signal counting means, a target sector detection error will also occur.

A servo signal detected at a position other than the position predicted by the above-mentioned position servo signal detection position prediction means is treated as a servo signal detected due to a data error and is not an original servo signal, and the counting of the servo signal counting means is stopped. Prevent target sector detection errors.

As described above, in the control system of a floppy disk device that uses the sector servo method as a tracking servo, by controlling the servo signal detection means, the servo signal counting means, and the servo signal detection position predetermining means, it is possible to This makes it possible to minimize the decrease in

Furthermore, in order to improve the reliability of target sector detection, ID information may be added to each sector. In this case, when writing data, the gap area between the two ministries can be made unnecessary by writing 10 pieces of information together with the data. Along with this, check the 10 information when writing data.

If you want to do this for the sector immediately before the target sector,
The reliability of detection of the target sector is hardly impaired.6I Embodiment 1 Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a sector position detection method in a floppy disk drive control system according to the present invention. Details will be described later.

FIG. 2 is a diagram showing the configuration of a floppy disk device for realizing the floppy disk device control method of the present invention. In FIG. 2, 101 is a recording medium on which a floppy disk device records data, and 102 is a recording medium 1.
This is a recording medium rotating device for rotating 01. A direct drive motor is normally used as the recording medium rotating device 102. Reference numeral 103 denotes a magnetic head for recording signals on the recording medium 101 or for reproducing signals recorded on the recording medium 101. The magnetic head 103 is fixed to a carriage 104, and by moving the carriage +04 by a track positioning device 105, the magnetic head 103 is moved to a target track on the recording medium 101. Track positioning device 105
A step motor is often used in floppy disk drives. The signal reproduced from the recording medium 10+ by the magnetic head 103 is transmitted to the reproduction amplifier 107.
The signal is amplified by the data reproduction circuit 108, the servo signal detection circuit 109, and the position error signal detection circuit 110. The data reproducing circuit 108 is a recording medium! This is a circuit for reproducing signals other than servo signals among the signals reproduced from 01 as data, and reproduces them as digital data. The servo signal detection circuit 109 detects the recording medium 10
The position error signal detection circuit 110 is for detecting a position error signal used for track positioning of the magnetic head 103 in the tracking servo. be. The index pulse detection circuit +06 generates one index pulse every time the recording medium 101 rotates once. Index pulse is recording medium +01
By detecting index holes provided at ten IM locations on the circumference of the recording medium rotating device 102,
is generated by outputting one signal per revolution. The servo signal detection position prediction circuit I11 detects the primary servo signal when the servo signal is detected based on the index pulse output from the index pulse generation circuit 106 or the signal indicating that the servo signal output from the servo signal detection circuit 109 has been detected. Find the predicted position. The pseudo servo signal detection circuit 112 prevents signals other than servo No. 14 from being mistakenly detected as servo signals. servo signal is interpolated to that position. The servo signal counting circuit 114 counts the number of detected servo signals. Pseudo servo signal detection circuit +1
2 and the outputs of the servo signal interpolation circuit 113 are logically ORed by an OR circuit 122 that performs a logical OR operation. TiT is calculated, and this output is input to the servo signal counting circuit 114 as a signal for incrementing the count, and the number of servo signals is counted. The servo signal end detection circuit 11.7 detects the end position of the servo signal. A control circuit 118 controls the entire floppy disk device. The track positioning device 105 is controlled based on the position error signal detected by the position error signal detection circuit 110, and the magnetic head +
03 to the target track on recording medium +01.

Also, the recording medium rotation device 1.02 is controlled to rotate the recording medium 1.
01 rotation control is performed. Target sector number setting circuit +16
The control circuit 118 sets the number of the target sector. A comparison circuit 115 compares this value with the 3t=x result of the servo signal counting circuit 114.

The drive ink face 11G provides a connection between the floppy disk device and the system using this floppy disk device.

FIG. 3 shows the disk format of the recording medium 101 used for recording data in a floppy disk device that employs the floppy disk device control system of the present invention.8 As shown in the disk format 126, an index pulse detection circuit is used. Index pulse 1 output by 106
The time point at which time T has elapsed from the position of the pulse 124 of No. 23 is defined as the track start position. index pulse 12
3, from pulse 124 to pulse 125 is one track. First, the nth servo signal 131 is recorded, and then the first sector 128 is recorded. From then on, 1 track is n
For example, if the sector is composed of 129 sectors, the second servo signal 129, the second sector 130 .
. . . Servo signals and sectors are recorded alternately, such as the n-th servo signal 131 and the n-th sector 132. Data 1 sector is the area where the user records data.
34, an error detection/correction code 135 for detecting and correcting reproduction errors of this data +34, and a gap 136 for absorbing a shift in the recording end position of the data 134 and error detection/correction code +35. be done.

When recording data, use data +34 and error detection/
The correction code 135 is recorded continuously. Even if the recording start position of the data 134 is the same, the recording end position of the error detection/correction code +35 may change due to rotational fluctuation of the recording medium +01 or the like. The gap 136 is set so that even if the recording end position shifts backward due to this shift, it does not cover the next servo signal. The reason why the track start position is set after the position of the pulse 124 of the index pulse +23 by the time T is to cope with the detection error of the index pulse 123. As mentioned above, the index pulse 123 is a recording medium! 0!
Since the detection is performed mechanically from the recording medium rotation device 105 or from the recording medium rotation device 105, an error occurs in the detection position. If t represents mm at this detection position in terms of time, then if t<T is satisfied, pulse 12 of index pulse 123
Even if the detection position shifts backward due to the error in the detection position of No. 4, the first servo signal 127 will not become undetectable.

The processing flow of the floppy disk device control system of the present invention in the configuration of the floppy disk device shown in FIG. 2 and the disk format of the recording medium shown in FIG. 3 will be explained with reference to FIG.

First, the control circuit 118 controls the recording medium rotating device 102 to rotate the recording medium 101, and controls the track positioning device 105 to move the magnetic head 103 to a target track on the recording medium 101. At this time, tracking servo control is performed based on the position error signal detected by the position error signal detection circuit 110. Next, the number (m) of the target sector is set in the target sector number setting circuit 116 (step l),! and waits for the pulse 124 of the index pulse 123 to be output by the index pulse detection circuit l port 6 (step 2).When the pulse 124 of the index pulse 123 is detected, this signal is sent to the servo signal detection position prediction circuit. 1
．． 11 and a servo signal counting circuit 114.

In the servo signal counting circuit 114, the index pulse 12
When the third pulse 124 is input, the count 8n is reset to zero (step 3), and the servo signal detection position prediction circuit Ill inputs the first servo signal 1 that is subsequently detected.
Predict the position of 27 (step 4). magnetic head 10
The signal read from servo signal detection circuit 109 is amplified by reproduction amplifier 107 and input to servo signal detection circuit 109 . When the first servo signal 127 is detected by the servo signal detection circuit 109, a signal indicating that the first servo signal 127 has been detected is manually input to the pseudo servo signal detection circuit 112 and the servo signal interpolation circuit 113. When the first servo signal 127 is detected by the servo signal detection circuit +09 (step 5)
, the pseudo servo signal detection circuit 112 checks whether the position is the position predicted by the servo signal detection position prediction circuit lit in step 4 (step 7). If the position is different from the predicted position in step 4, the process returns to step 5 and waits for the servo signal to be detected by the servo signal detection circuit +09 again. Position predicted by servo signal detection position prediction circuit Ill and servo signal detection circuit 1
Verification with the position of the servo signal detected by step 09 (step 7) is performed by the pseudo servo signal detection circuit 112. As a result of the verification, if the position is predicted by the servo signal detection position prediction circuit +11, the pseudo servo signal detection circuit +12 outputs a signal indicating that the first servo signal 127 has been detected.
It is output to the servo signal counting circuit +14 through the OR circuit 122. The output signal of the OR circuit +22 indicating that the first servo signal 127 has been detected is the servo signal counting circuit +22.
In addition to 14, the signal is also input to a servo signal detection position prediction circuit I11. The servo signal detection position prediction circuit lll uses index pulse 1 when predicting the position where the first servo signal 127, which is the servo No. 48 at the top of rack i, is detected.
, 23 based on the position where the pulse 124 is detected.
On the other hand, when predicting the position at which subsequent servo signals will be detected, this is done based on the detection position of the previous servo signal. For example, the position where the second servo signal 129 is detected is predicted based on the position where the first servo 4g 127 is detected. In step 5, the servo signal detection circuit 10
If the servo signal is not detected in step 9, it is checked whether the position predicted by the servo signal detection position prediction circuit I11 has been reached (step 6). If the position predicted by the servo signal detection position prediction circuit lit has not been reached,
Wait for the servo signal detection circuit 109 to detect the servo signal again (step 5), the servo signal detection circuit 109
The servo signal interpolation circuit 113 checks the presence or absence of servo signal detection in the servo signal detection circuit III and the position of the servo signal detection position prediction circuit III. If the servo signal detection circuit 109 does not detect the servo signal and the position predicted by the servo signal detection position prediction circuit lit is reached in step 4, the servo signal interpolation circuit 113 detects the main signal detection position prediction circuit lit. The OR circuit 122 outputs a signal indicating that a servo signal has been detected at the predicted position.
The signal is output to the servo signal counting circuit 114 through the servo signal counting circuit 114. As mentioned above, this signal is transmitted to the servo signal detection position prediction circuit Ill.
is also entered. In the servo signal counting circuit 114, servo signal interpolation circuit +13 or pseudo servo signal detection circuit +1
When a signal indicating that a servo signal has been detected is inputted via the two-to-one circuit 122, the count n is incremented by 1 (step 8). Here, the count content n is compared with the target sector number m set in the target sector number setting circuit 116 by the comparison circuit 115 (step 9). In the case of m-J-n, the process returns to step 4 and repeats the operations from this step onward.If m=n, the servo signal immediately before the target sector is detected, and the end position of that servo signal is the target sector. This is the starting position of the sector. For example, when the second sector 130 is the target sector in FIG. Therefore, the count content of the servo signal counting circuit +14 becomes 2, which matches the target sector number. Servo 8 is used to detect the end position of the servo signal.
Issue end detection circuit! ! 7 performs (step 10). If the comparison result of the comparison circuit 115 is m=n, the signal indicating that the servo signal immediately before the target sector has been detected is controlled (6 control circuits + 18 output to the summation circuit 118 are
15 and the servo signal end detection circuit 117
The starting position of the target sector is determined based on the signal outputted by (step 11).

Figure 4 shows the disk format 12 of the recording medium in Figure 3.
6 is an example of the configuration of the servo signal in FIG. The servo signal 138 is sandwiched between the front and rear sectors +37 and +39. The servo signal 138 is recorded with the boundary between tracks as the center line. For example, the (n-th
1) With the boundary line between the track 140 and the nth trunk +41 as the center line, and between the nth track 141 and the (n+
1)) Recorded with the boundary line with the rack 142 as the center line. In FIG. 4, the arrow of the servo signal indicates the direction in which the recording medium is magnetized. A reproduction signal 143 in FIG. 4 is a reproduction signal when the magnetic head 144 travels over the recording medium in the magnetic head traveling direction. A signal with beats is reproduced when the magnetization direction changes. Reproduction signal 145.146°1
47 and 148 are called synchronization signals, which are recorded with magnetization reversal positions in all servo signals between tracks. By detecting this synchronization signal, it is confirmed that it is a servo signal. Also, since the time from the beginning of the servo signal to the first synchronization signal 145 is fixed,
After detecting the synchronization signal 145, the position at which time Ts has elapsed can be detected as the end position of the servo signal 138. As shown in FIG. 4, the magnetic head 144
If the servo signal is read out from the center line of track 140 toward the (n-1)th track 140, the (n-1)th) rack +4
The peak value of the reproduced signal 150.151 of the servo signal recorded with the boundary line between 0 and nth track +41 as the center line, and the nth track +41 and (n+1)th track 142
A difference occurs in the peak values of the reproduced signals 152 and 153 of the servo signals recorded with the boundary line as the center line. This is because the widths at which the magnetic head 144 reproduces each servo signal are different. Therefore, when the position of the magnetic head 144 is adjusted so that the peak values of the reproduced signals of the respective servo signals, that is, the reproduced signals 150 and 152 are equal, the magnetic head +44 runs along the center line of the n-th track 14+. .

This reproduction signal 150. +51.152.153 is called a position error signal.

FIG. 5 is a diagram showing the states of each signal when the control shown in FIG. 1 is performed in the configuration of the floppy disk device shown in FIG. 3. As mentioned above, disk format h126
is a servo signal and sectors arranged alternately,
Furthermore, the first servo signal 127 is the index pulse 12
3 is recorded a time T after the position of the pulse 124. At the position where pulse 124 of index pulse 123 is detected, the servo signal counting circuit! The output of 14 is reset to zero (state 158). Further, the servo signal detection position prediction circuit I11 outputs a pulse 159 at a position where the first servo signal 127 is predicted to be detected. This position is output as a pulse with a certain width so that the first servo signal 127 can be detected even if a shift occurs in the detection position of the first servo signal 127 due to rotational fluctuation of the recording medium or the like. If the first servo signal 127 is detected during this pulse, it is assumed that the servo signal is detected at the correct position. When the first servo signal 127 is detected by the servo signal detection circuit 109, a signal pulse 160 indicating that a servo signal has been detected is output. When the position of this pulse 160 is between the pulses 159 output by the servo signal detection position prediction circuit 114, the pseudo servo signal detection circuit 2 outputs the servo signal detection circuit l port 9.
0 is output to the servo signal counting circuit +14 as a result of normally detecting the l-th servo signal 127. Servo signal counting circuit 114 is manually operated by pseudo servo signal detection circuit 112
The OR circuit 122 performs an OR operation on the respective signals output from the and servo signal interpolation circuit +13. By manually inputting the pulse 161 from the pseudo servo signal detection circuit 112 to the servo (No. 4 counting circuit 114-), the output 157 of the servo signal counting circuit 114
The count is advanced by 1 and becomes 1'' (state 162),
Servo signal detection position prediction circuit 1.1. l indicates the position where the second servo signal 129 is detected relative to the first servo signal 12
A preliminary calculation is made from the detected position of 7.

Next, a description will be given of processing when the servo signal is not detected for some reason, such as a scratch on the recording medium. According to FIG. 5, the third servo signal 163
However, due to scratches on the recording medium, the servo signal detection circuit 1
Suppose that it was not detected in 09. The servo signal detection position prediction circuit Ill moves from the position where the second servo signal 129 is detected to the position where the third servo signal 163 is predicted to be detected.

A six-point signal interpolation circuit 113 that outputs pulse +64, which is the output of the servo signal detection position prediction circuit 11I, monitors the output of the servo signal detection circuit 109 and the output of the servo signal detection position prediction circuit III, and Signal detection is expected! During the period of the pulse signal output to the position where it is
If a signal indicating that a servo signal has been detected is not inputted from the servo signal detection circuit 109, the servo signal counting circuit 1 is activated at the position (time point) at which the servo signal is predicted to be detected.
14, it outputs the same signal as the signal output by the pseudo servo signal detection circuit +12 when a servo signal is detected, that is, a pulse 165. If a normal servo signal is detected by the servo signal detection circuit 109, a signal indicating that the third vehicle signal 163 has been detected is output to the position 166 of the servo signal detection circuit 109 output. Servo signal interpolation circuit 1 instead of pulse
13 is a pulse equivalent to this, and the servo signal counting circuit 11
Output as pulse +65 shown in 4 manpower. As a result, the count contents are advanced by 1 in the servo signal counting circuit 114,
As shown in the output of the servo signal counting circuit 114 in FIG.
3'' (state 167).

Next, processing when a servo signal is detected at a position where a servo signal is not expected to be detected will be described. For example, if the data in the fourth sector 168 is not reproduced properly,
If the signal is reproduced as the same signal as the servo signal, the servo signal detection circuit 109 will recognize that the servo signal has been detected. In FIG. 5, the fourth sector 168
Assume that the servo signal detection circuit 109 detects the data therein as a servo signal through reproduction, and outputs a pulse 169 shown in the output of the servo signal detection circuit 109.

The pseudo servo signal detection circuit +12 monitors the output of the servo signal detection position prediction circuit 111 and the output of the servo signal detection circuit 109, and detects that the servo signal detection position prediction circuit Ill does not predict that a servo signal will be detected. The servo signal output by the servo signal detection circuit 109 is detected during the period (that is, when the pulse to be output to the position where the servo signal detection position prediction circuit 11.1 predicts that the servo signal is detected is not output). The signal indicating this is determined to be a pseudo servo signal (the servo signal detection circuit 109 incorrectly detects a reproduced signal that is not a servo signal as a servo signal), and the servo signal is detected by the servo signal counting circuit 114. In Fig. 5, the servo signal detection circuit 109 detects a pseudo servo signal as a servo signal and outputs a pulse 169, but the servo signal counting circuit +14 indicates that a servo signal has been detected. Since no signal is input, the servo signal counting circuit 114
The count content remains unchanged at "4". (Condition 1.70).

As described above, the output of the servo signal detection circuit 109 and the servo signal detection position prediction circuit 111 are detected by the pseudo servo signal detection circuit 1128 and the servo signal interpolation circuit 113.
By monitoring the output of the servo signal counting circuit [ 14, the value of the number of detected servo signals being counted;
To prevent data from being recorded or reproduced in a sector that is not a target sector because the sector number of the sector immediately after each servo signal is different.

FIG. 6 shows a control method for recording and reproducing data in a sector when a target sector is detected by detecting the target sector in the control method of the floppy disk device of the present invention explained in FIG. . In FIG. 6, a case will be described in which the target sector is the first sector 128.

As mentioned above, the servo signal detection position prediction circuit I11 detects the first servo signal! 27 is expected to be detected,
A pulse 159 shown at the output 155 of the servo signal detection position prediction circuit Ill is output. The first servo signal detected by the servo signal detection circuit 109 at the position where this pulse 159 is output! After 27 is confirmed by the pseudo servo signal detection circuit 112 to be the correct servo No. 13, that is, it is not a pseudo servo signal, it is manually input as a pulse 161 through the OR circuit 122 as shown in the servo signal counting circuit 114. . In the servo signal counting circuit 114, the count is incremented by one in response to the pulse 161.

As a result, in the example of FIG.
A signal indicating that the detected servo signal is the servo signal immediately before the target sector, in this case, the first servo signal 127 immediately before the first sector 128, is compared with the target sector number set in the target sector number. It is input to circuit l18. 6th
As shown in the output of the comparison circuit 115 in the figure, after the pulse 161 is manually applied to the servo signal counting circuit 114, then the pulse 161 is manually applied to the servo signal counting circuit 114, and then the pulse is first applied to the servo signal counting circuit 114. Until the signal 172 is input, a signal 173 indicating that the result of comparing the count result of the servo signal counting circuit 114 and the value of the target sector number set in the target sector number setting circuit 116 is equal is output. . Furthermore, servo signal end detection circuit 1
17 outputs a pulse 175 that is turned on at the position where the servo signal detection circuit 109 outputs a signal indicating that the servo signal has been detected, and turned off at the end position of the servo signal. As explained in FIG. 4, the servo signal detection circuit 10
9 detects that the servo signal is a servo signal by detecting the synchronization signal of the servo signal. Therefore, the servo signal end detection circuit 117 detects the servo signal from the servo signal detection circuit 109 from the signal indicating that the servo signal input manually is detected. 4 figure 149
It is sufficient to output the pulse for only the time Ts shown by .

The output of this servo signal end detection circuit 117 is input to a control circuit 118. If the control circuit 118 internally outputs a signal indicating that the comparison circuit 115 has detected the servo signal immediately before the target sector, the control circuit 118 determines the end position of the pulse of the output of the servo signal end detection circuit 117 in the target sector. Data recording or data reproduction is performed as the starting position. The data 134 and error detection/correction code 135 in the sector shown in the disk format 126 in FIG. 3 are as follows:
c! Record or play. As shown in the data read/write period signal +76 in FIG. 6, the time Trw for recording or reproducing data corresponds to the time for this data 134 and the error detection/correction code 135.

As described above, in the control method of the floppy disk device of the present invention, the position of the target sector is detected based on the number of servo signals detected from the beginning of the track. The starting position of each sector is the ending position of the immediately preceding servo signal. Such a control system eliminates the need for an ID field and a gap area between a servo signal and a sector in a floppy disk device that uses a sector servo system as a tracking servo. Therefore, it is possible to suppress a decrease in memory capacity. Roughly speaking, the pseudo servo signal detection circuit and the servo signal interpolation circuit prevent incorrect detection of the target sector, inability to detect the target sector due to the servo signal becoming undetectable, or detection errors.

In the embodiment described above, the comparison between the target sector number and the number of detected servo signals is performed by the target sector number setting circuit,
Although this is done by a comparison circuit, it is also possible to do it inside the control circuit, for example by using a control circuit with arithmetic capabilities like a microcomputer.

Furthermore, it is also possible to directly input the output of the OR circuit indicating that a servo signal has been detected to the control circuit, and to have the control circuit count the number of detected servo signals.

In the embodiments described above, the position of the target sector is determined by counting the number of detected servo signals. In order to ensure that the sector recorded at the position detected by this method is the target sector, the configuration within each sector shown in the disk format 126 of FIG. 3 is shown in FIG. 7. It is conceivable to make it a thing. This configuration has ID information 178 added to the intra-sector configuration of the embodiment described above. This addition (i7
The location may be before or after the data 134. This ID information f[
+178 is different from the ID field in the conventional soft sector system, and is recorded together when data 134 is recorded. In the conventional soft sector method, the ID field is not recorded when recording data; even when recording data, it is confirmed that it is the target sector by reading the ID field, and it is confirmed that it is the target sector. If this is confirmed, follow the 10 fields (
Data was recorded in the data area. If the structure is such that an ID field is read out and data is recorded in the following data field like a soft sector, it is necessary to provide a gap area between the ID field and the data field. Therefore, as shown in Figure 7, IDkf report 178 is also data! By adopting a configuration in which data 1178 and data 134 are recorded at the same time, it is possible to create a configuration in which no gap area is provided between [D information t[1178 and data 134].

In order to realize this method, an ID information detection circuit 1 is added to the configuration of the floppy disk device shown in FIG. 2 as shown in FIG.
Add 79. The ID information detection circuit +79 detects the ID information 178 from the re/L data and sends its contents to the control circuit l.
Output to 18. When reproducing data, the procedure is the same as in the previous embodiment. That is, the position of the target sector is detected by detecting the servo signal immediately before the target sector, and the ID information of the data read from the sector is detected.
8 to confirm that the reproduced sector is the target sector. The control method for data recording is different from the previous embodiment.

A data recording control method in this embodiment will be described with reference to FIG. Assume that the fourth sector 180 shown in the disk format 126 is the target sector. In the embodiment described above, the number of the target sector was set in the target sector number setting circuit +16, but in this embodiment, a value obtained by subtracting 1 from the number of the target sector is set. If the target sector is 4", set "3" in the target sector number setting circuit 116. As shown in the control wholesale state +81, the first servo No. 4+2
7, a servo signal is generated by the same operation as in the previous embodiment (state 182). Similarly, the second servo signal 129 is also regenerated (state 183). Due to the operation described in the above embodiment, the output of the servo signal counting circuit 114 is "2" at the position where the second servo signal 129 is detected.
(state!84). The servo signal of the third servo signal 163 is similarly reproduced (state 185). At this time, the output of the servo signal counting circuit 114 becomes °°3''(state!3'').
186), as described above, the target sector number setting circuit 11
As a result of comparing the number set in 6 with the comparison circuit 115, the servo signal immediately before the sector with the number set in the target sector number setting circuit 116, in this case, the third servo signal 1.
The control circuit 118 is notified that 63 has been detected.

At this time, the control circuit 118 follows the detected servo signal (
Control the reproduction of sectors. As shown in the control state 181, the data is re-read 187 and the third sector 1
Play 88. From this reproduced signal, the ID information 178 shown in FIG. 7 is detected by the IDt# information detection circuit 179,
Output to control circuit 118. The control circuit 118 is rot+
ID information detected by ff information detection circuit 179 +17178
It is confirmed that the reproduced sector is the sector one -L before the target sector (in the case of FIG. 9, the target sector is the fourth sector +80, so the third sector 188). If the ID information detected at this time is correct, then the fourth
The servo signal 189 is reproduced 190 and data is recorded 11191 in the fourth sector 180 using the same control method as in the previous embodiment. As described in iii, in this data recording, the ID information 178 and data 134 shown in FIG. 7 are recorded without providing a gap area in between. In this way, by reproducing the sector immediately before the target sector and confirming the ID information of that sector, it is possible to improve reliability during data recording.

As described above, in the data recording control method according to the present embodiment, by checking the ID information of the sector facing the target sector, it is possible to improve the reliability of data recording to the target sector. As in the embodiment described above, since control is performed such that the end position of the servo signal of sector 11 is the start position of the sector, there is not only a gap area between IDfF[ and data but also a gap area between the servo signal and the sector. Therefore, by using the sector servo method as a tracking servo, it is possible to reduce the decrease in storage capacity in a floppy disk device with improved track density. be.

[Fuka of the Invention] According to the present invention, the detection of the start position of the target sector is waited for depending on the number of detected servo signals from the beginning of the track, and the end position of the servo signal immediately before the target sector is determined as the start position of the sector. There is no need to provide an HD field for recording sector attribute information in each sector.
In addition, there is no need to provide a gap area between the servo signal and the sector to absorb fluctuation factors, so the storage capacity is reduced in floppy disk drives that use the sector servo method as the tracking servo to improve track density. This makes it possible to reduce the

[Brief explanation of the drawing]

FIG. 1 is a flowchart of the processing of the floppy disk device control method of the present invention, and FIG. 2 is a block diagram showing the configuration of the floppy disk device for realizing the floppy disk device control method of the present invention. Figure 3 shows the floppy disk shown in Figure 2.
Figure 4r-21 is an explanatory diagram of one embodiment of the servo signal configuration; Figures 5 and 6 are the floppy disk of Figure 2 in the processing flow of Figure 1;・Signal state diagram showing signal states of the disk device; FIG. 7 is an explanatory diagram of the sector configuration in the second embodiment of the floppy disk device control method of the present invention; FIG. 8 is the second embodiment A floppy disk to realize
FIG. 9 is a block diagram showing the configuration of the disk device; FIG. 9 is a signal state diagram showing the states of the floppy disk device signals in FIG. 8 in the second embodiment; FIGS.
Figure 2 is an explanatory diagram for explaining the control system of a conventional floppy disk device, Figures 13, 14, and 15.
The figure is an explanatory diagram for explaining the configuration of a tracking servo in a floppy disk device. 101... Recording medium, 103... Magnetic head, 106... Index pulse detection circuit, 109...
・Servo signal detection circuit, +10...Position error signal detection circuit, III...Servo signal detection position prediction circuit, 112...
- Pseudo servo signal detection circuit, 11... Servo signal interpolation circuit, +111... Servo signal counting circuit, 115... Comparison circuit, 116... Target sector number setting circuit, 118... Control circuit, 123... Index pulse, +26... Disc format. Applicant Hitachi, Ltd. Representative Patent Attorney Tomi 1) Kazuko Figure 1 Figure 4 Figure 6 Figure 7
? “・)Figure 1o (a) (b) Figure 13 (a) (b) Figure 14 Figure 15 (a) (b)

Claims (1)

[Claims] One track is divided into a plurality of sectors, data is recorded and reproduced in each sector, and track positioning is performed by a servo signal recorded between sectors. 1. A control method for a disk device, characterized in that the number of detected servo signals from a track start position is counted, and a target sector is recognized based on the counted value. 2. When writing data to the sector, detect the sector immediately before the target sector by counting the number of detected servo signals, and after confirming the ID information read from the sector immediately before, write data to the target sector. 2. The control method for a disk device according to claim 1, wherein the data is written together with ID information of the sector. 3. In a disk device in which one track is divided into a plurality of sectors, data is recorded and reproduced in each sector, and track positioning is performed by a servo signal recorded between sectors, the servo signal is servo signal detection means for detecting; servo signal counting means for counting the servo signals detected by the detection means; target sector number setting means for setting the number of the target sector; and a value set in the setting means. and a comparison means for comparing the count results of the counting means, and the starting position of the target sector is recognized based on a matching output of the comparison means. 4. An end position detection means for detecting the end position of the servo signal is provided, and the end position of the servo signal is set as the start position of the target sector in accordance with a coincidence output of the comparison means. Control method of the disk device described. 5. The disk device according to claim 3, further comprising a servo signal detection position prediction means for predicting a position where the servo signal is detected, and counting by the counting means is controlled based on an output of the means. control method. 6. When the servo signal is detected at a position predicted by the prediction means, the counting means is stepped, and when the servo signal is detected at a position other than the predicted position,
6. The control system for a disk device according to claim 5, further comprising pseudo servo signal detection means that does not advance said counting means. 7. Control of a disk device according to claim 5, further comprising servo signal interpolation means for forcibly stepping the counting means when the servo signal is not detected at the position predicted by the prediction means. method.