JPH06243590A - Recording format and magnetic disk device using same - Google Patents

Abstract

PURPOSE:To eliminate an ID part duplicate in the contents of information and to increase storage capacity by providing a servo sector with areas for recording a start signal for operating a head positioning servo circuit, cylinder position information and a signal for detecting the amt. of misalignment of a head respectively. CONSTITUTION:An AGC part 19, a cylinder address part 20 and an offset burst part 21 are provided in the servo sector 16 of the recording format. The AGC part 19 is recorded with a synchronizing pulse for starting operation of the head positioning servo circuit, while the address part 20 with the information of a cylinder where the head is positioned, and the burst part 21 with the amt. of misalignment of the head from the center of a track respectively. A cylinder address, a head number and a sector address are decided by the device from information read out of the sector 16 and information provided inside and by individual means concerned, and the quality of the sector is judged from bad sector information. Thus, servo control is performed, and also an ID part duplicate in the contents of information is deleted so that the storage capacity can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a position information recording system for a magnetic disk device.

[0002]

2. Description of the Related Art Conventionally, in a magnetic disk device, I
Part D (cylinder information, head information, sector information, pass / fail judgment flag of the sector, etc. are included therein)
To read / write data. Further, in a sector servo type magnetic disk device, in order to position the head at a predetermined position, the I
In addition to the D section, it had a servo sector containing cylinder information. However, there is no information included in the ID section that can be obtained only by the ID section. The cylinder information is also stored in the servo sector, and other information is stored in some form as internal information of the device control unit. That is, the information is duplicately recorded and the data recording capacity is reduced.

Next, a specific description will be given with reference to FIGS. 4, 5 and 6.

FIG. 4 is a block diagram showing a portion for reading information relating to device control in a conventional magnetic disk device. In FIG. 4, the magnetization information written on the surface of the disk medium through the read circuit 1 is converted into an electric signal. Servo sector information 2 and I as converted electric signals
Information 14 of the D part is obtained. The servo sector information 2 becomes a cylinder address 3, a sector number 4, a head address 5 and a bad sector flag 12 by a decoder called a Sago address decoder 6.

FIG. 5 shows what kind of magnetized information is recorded on a conventional disk medium and how it is recorded. FIG. 5A shows magnetization information in one round on the disk medium. Is a schematic representation of how is recorded. On the conventional disk medium, there is only one index part 18 and one servo sector 16, I
The D section 22 and the data section 17 are written. Then, the servo sector 16, the data portion 17, and the ID portion 22 are sequentially recorded a plurality of times. Further, FIG. 5D shows how these pieces of magnetization information are recorded on one track. Further, the ID section 22 includes a cylinder information section 23, a head information section 24, and a sector pass / fail information section 25.

FIG. 6 shows what kind of pattern is actually recorded on the surface of the disk medium by the method shown in FIG. 5. The AGC section 19, the cylinder address section 20, the offset burst section 21, Cylinder information section 2
3, a head information section 24, a sector pass / fail information section 24, and a data section 17.

As described above, in the conventional magnetic disk device, the cylinder address 3 is recorded in the servo sector information 2 and the ID portion information 14 in an overlapping manner, as is apparent from FIG. That is, the servo sector 16 and I in FIG.
In addition to the D section 22, the cylinder address section 20 in FIG.
The same information is recorded in the cylinder information section 23.

[0008]

In the above-mentioned conventional sector servo type magnetic disk apparatus, the same information exists in the ID section and the servo sector of the recording format of the disk medium, and in the apparatus control section of the magnetic disk apparatus. Also ID
The information contained in the copy exists and is redundant. As described above, when the duplicate information exists on the disk medium, there is a drawback that the data storage capacity is reduced.

[0009]

According to a first aspect of the present invention, there is provided a storage format including an index portion, a servo sector and a data portion on a disk medium, wherein the servo sector stores an operation start signal of a head positioning servo circuit. It is characterized by including an AGC section, a cylinder address section for recording cylinder position information, and an offset burst section for recording a detection signal for detecting a positional deviation amount of the head.

A second invention is a magnetic disk device using the recording format of the first invention, wherein a cylinder address, a head number, and a cylinder number are read from the servo sector information read from the recording format and the internal information stored in the device control section. The present invention is characterized by comprising address determining means for determining a sector address and sector pass / fail determining means for determining whether or not the sector is a bad sector from the bat sector information recorded in advance on the disk medium. Further, a semiconductor memory device may be provided to store the bad sector information.

[0011]

The present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a portion for reading information relating to device control in a magnetic disk device according to an embodiment of the present invention. The same reference numerals are used for the same components as in the conventional example. In FIG. 1, the read circuit 1
The magnetization information written on the surface of the disk medium is converted into an electric signal. Servo secreter information 2 and bad sector information 9 are obtained as the converted electric signals. The servo sector information 2 becomes a cylinder address 3 by a decoder called a servo address decoder 6, and the servo sector information 2 includes the control unit internal information 8 and the address determining means 7.
The sector number 4 and the head address 5 are also obtained by and.

On the other hand, the bad sector information 9 is once stored in a storage unit such as the memory 10 and then becomes a bad sector flag 12 by the sector pass / fail judgment means 11 together with the signals of the cylinder address 3, the sector number 4 and the head address 5. A portion including the servo address decoder 6, the address determining means 7, the control unit internal information 8, the memory 10, and the sector quality determining means 11 is called a device control unit 13.

By effectively using the servo sector information and the control internal information in this way, even if the ID part is deleted, information having the same contents as before can be obtained.

FIG. 2 shows what kind of magnetization information is recorded on the disk medium and how it is recorded. FIG. 2A shows how the magnetization information is recorded in one round on the disk medium. This is a schematic representation of whether or not the data is recorded as described above. On the disk medium, an index portion 18, a servo sactor 16, and a data portion 17, which are only one in one turn, are written. The servo sector 16 and the data section 17 are alternately recorded a plurality of times. Further, FIG. 2B shows how these pieces of magnetization information are recorded on one track. Further, the servo sector 16 comprises an AGC section 19, a cylinder address section 20 and an offset burst section 21.

FIG. 3A shows what kind of pattern is actually recorded on the surface of the disk medium by the method shown in FIG. 1, and FIG. 3B shows an actual magnetic disk. 1 schematically shows the inside of the device. Figure 3
In (b), in the disk device of the present invention, the disk medium 27 surrounded by the disk housing 26 and a carriage 31 for supporting the head 30, and a portion where the head 30 and the carriage 31 are integrated are arranged in a radial direction of the disk medium 27. An actuator coil 32 that drives the actuator coil 32, a permanent magnet 33 that is necessary for the actuator coil 32 to rotate due to magnetic force when a current is applied to the actuator coil 32, and a spindle motor 34 that is a drive unit that rotates the disk medium 27. To be done. 28 is one track (for example, the innermost track) on which information on the disk medium is recorded, and 29 is one track on which information on the disk medium 27 is recorded similarly to the track 28. Indicates that the part is different from the track 28.

If the position information recording method shown in FIG. 2 is used, the servo system circuit is put into operation by the synchronizing pulse in the AGC section 19. When the cylinder information section 20 written in Gray code is read into the circuit, it is decoded by the servo address decoder 6 and the number of inders at which the head is currently located is stored in the storage section.

Next, the offset burst unit 21 detects the amount of displacement of the head from the track center. When the head is not located at the track center, the servo control circuit can be operated so as to reduce the positional deviation amount, and the head can be guided to the track center.

The servo sector 16 is composed of an AGC section 19, a cylinder address section 20 and an offsat burst section 21, and the servo sector 16 and the data section are written a plurality of times during one round of the disk medium, but how many times on the circumference. Whether to write is determined by the length of the sampling cycle of the position information required by the servo system. The larger the number of times, the more stable the positioning can be realized.

Further, even if there is a slight rotation deviation of the spindle motor 34, or if the carriage 31 sways due to some influence, if the number of servo sectors 16 is large, those influences are canceled by performing servo control. This does not affect the positioning of the head at a predetermined position. However, in the magnetic disk device, it is required to write magnetization information of as much data as possible within a determined area of the disk medium. It is considered that the storage capacity of the magnetic disk device is affected by how many times the area of the servo sector 16 appears on the same circumference. Therefore, it is practically desirable that the number of times is as small as possible.

Conventionally, the usage of the servo sector and the information of the ID part have been treated as separate items. for that reason,
In the present invention, there is an overlapping portion between two pieces of information, and in the present invention, the portions in which the same contents are written are combined into one, and what is held as internal information in the device control unit is:
It is judged again that it is not necessary to write the magnetization information on the disk medium, and it is attempted to increase the storage capacity by omitting it.

Conventionally, only the cylinder number is included in the servo sector information. On the other hand, in the read / write ID section, cylinder information, head information and sector pass / fail flag are written. However, in the head information, the circuit section recognizes which head is currently selected,
Regarding the sector number, it is possible to substitute the index pulse, which is the starting point of one round of the disk medium, by counting the number of disks.

Further, this flag is a flag for judging whether the sector is good or bad. This information is also a semiconductor memory element, for example, E.
It can be stored in an EPROM or the like, and bad sector information is collectively recorded in an area that is not used as a data area of the disk medium so that the magnetization information can be recorded in a setup state immediately after the disk device is powered on. It is also possible to substitute by pre-reading and downloading.

As described above, only one piece of servo sector information is sufficient for positioning and reading / reading / reading the servo sector information which has been treated as separate information from the ID section information used for reading / writing. It is possible to satisfy the writing requirement.

Next, although data is written in the data section 17, the head is positioned at the center of the track by the position information recording method and the electric circuit for operating the head position as described above. Since it is determined, the head can read the data in the best state and can accurately write the data in the position where it should be written.

Further, the present invention is particularly effective for a magnetic disk device using an MR head utilizing the magnetoresistive effect as a read head. Conventional Ferai heads and thin film heads have been used for both reading and writing, but in a magnetic disk device using an MR head, the read head and the write head are independent, and the write head gap and the read head gap are different. The read head gap is mounted on one slider several microns apart. It should be noted that the gap position of the write head and the gap position of the read head are different when using this type of head in combination with the rotary positioning mechanism. When the write head is positioned at the track center position while the write command is issued, it is possible that the read head cannot read the part in which the ID part is described because the read head is off track.

However, according to the present invention, since the ID part is not written on the disk medium, it is not necessary to read the ID part, and the servo sector information is read by a predetermined head (the servo sector information can be read even if it is not the track center). ), And other information included in the conventional ID section can be complemented by hardware so that the head can be accurately and quickly positioned at a predetermined position. As a result, the problem of reading the ID section of the head, which has been a concern in the past, is eliminated, and the storage capacity of the disk medium can be increased as compared with the conventional case.

[0028]

As described above, according to the present invention, it is possible to increase the storage capacity by gathering the portions in which the same contents are written among the storage information on the disk medium. Further, there is an effect that it becomes unnecessary to consider the influence of the positional error between the two heads, which is a problem when using the MR head.

[Brief description of drawings]

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

FIG. 2 is a conceptual diagram showing a position information storage system of the magnetic disk device of the present invention.

3A and 3B are a conceptual diagram showing a concrete storage state on a disk medium according to FIG. 2 and a conceptual diagram showing a magnetic disk device including a disk medium in which position information is stored.

FIG. 4 is a block diagram showing a conventional example.

FIG. 5 is a conceptual diagram showing an example of a position information storage system of a conventional magnetic disk device.

6 is a conceptual diagram showing a concrete storage state on a disk medium in FIG.

[Explanation of symbols]

 1 Read Circuit 2 Servo Sector Information 3 Cylinder Address 4 Sector Number 5 Head Address 6 Servo Address Decoder 7 Address Determining Means 8 Control Part Internal Information 9 Bad Sector Information 10 Memory 11 Sector Pass / Fail Discrimination Means 12 Bad Sector Flag 13 Device Control Part 14 ID Part Information 15 read / write control section 16 servo sector 17 data section 18 index section 19 AGC section (automatic gain control section) 20 cylinder address section 21 offset burst section 22 ID section 23 cylinder information section 24 head information section 25 sector pass / fail information section 26 Disk housing 27 Disk medium 28, 29 Track 30 Head 31 Carriage 32 Actuator 33 Permanent magnet 34 Spindle motor

Claims (3)

[Claims] 1. A recording format comprising an index section, a servo sector and a data section on a disk medium, wherein the servo sector records an AGC section for recording an operation start signal of a head positioning servo circuit and cylinder position information. A recording format comprising: a cylinder address portion; and an offset burst portion for recording a detection signal for detecting a positional deviation amount of a head. 2. A magnetic disk device using the recording format according to claim 1, wherein a cylinder address, a head number and a sector address are determined from the servo sector information read from the storage format and internal information stored in a device control section. And a sector pass / fail determination unit that determines whether or not the sector is a bad sector based on bad sector information recorded in advance on the disk medium. 3. The magnetic disk device according to claim 2, further comprising a semiconductor memory element for storing the bad sector information.