JPH0477364B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic disk recording device, and in particular,
This invention relates to a technology for recording in a soft sector format using a single-gap magnetic head with a simple structure.

[Conventional technology]

As shown in FIG. 11, a write track 2 of a magnetic disk 1 such as a floppy disk includes a preamble section 3 starting from the detection position of the index signal 10, a plurality of (for example, nine) sectors 4 that follow, and the remaining sections. The postamble section 5 consists of a postamble section 5. Each sector 4 has a recognition field (hereinafter referred to as ID field) 6 in which the address of each sector is recorded, and a data field 7 in which data is recorded. A gap 8 is provided to protect the data. When using a blank magnetic disk 1 on which nothing has been written, a predetermined format as described above is recorded in advance over all tracks between the inner and outer circumferences of the magnetic disk 1. The magnetic disk is initialized, that is, the format is recorded.

In addition, in order to prevent information signals previously recorded on the magnetic disk 1 from remaining unerased and reading out information signals that should have been erased, both edges of the write track 2 where information signals are recorded are provided. An erase track 9 on which data has been erased is provided to prevent information signals from remaining erased.
The erase track 9 can be easily formed by using a so-called tunnel-type magnetic head that has a dedicated erase gap for the erase track 9, but a single-gap magnetic head with a simple structure and low cost can be used. In a device using
It is necessary to sequentially move the magnetic head to the side edge to form the erase track 9.

In a conventional single-gap head device, after new data is recorded on the write track 2, the magnetic head is sequentially moved to an intermediate position between the adjacent write tracks 2 on both sides, and the magnetic head is moved around the entire circumference of the track. Erasing was performed over the period of time to form an erased track 9. The reason why the data is erased over the entire circumference is that each sector 4 is constructed using a soft sector system, and if the magnetic head deviates from the write track 2 and is located at an intermediate position, each sector 4 cannot be identified.

For this reason, as shown in FIG. 12, the width of the write track 2 after writing is narrower than the original width at the time of format recording. In particular, with regard to ID field 6, once the format is recorded, it will not be rewritten during use, so if writing is performed on another magnetic disk recording device, the magnetic head of each recording device will be Due to variations in positioning error, the side edges of the writing track 2 are further erased,
The width of the IC field 6 is further narrowed by the above variation. As a result, reading margins such as signal level margins and positioning accuracy margins during read operations are reduced, causing problems in compatibility between magnetic disk recording devices, and a high degree of positioning accuracy is required to ensure compatibility. There was a problem with the requirements.

[Problem that the invention seeks to solve]

The present invention has been made to solve the above problems, and dramatically improves the reading margin during the read operation by preventing the writing track width from decreasing due to side edge erasure. It is an object of the present invention to provide a magnetic disk recording device that can easily ensure compatibility between recording devices.

[Means for solving problems]

For this reason, the present invention provides a write track for recording desired information signals on a magnetic disk using a single-gap magnetic head positioned along the surface of the magnetic disk between its outer and inner circumferences. In a magnetic disk recording device in which
A first step of moving the magnetic head from the center position of the desired write track to one side edge position, reading and confirming the identification field of the desired sector of the write track, and then erasing the data field portion of the sector. Next, the magnetic head is moved from the center position of the write track to the other side edge position, and after reading and confirming the identification field of the desired sector again, the data field portion of the sector is a second erasing means for erasing, and then moving the magnetic head again to the center position of the write track;
There is provided a magnetic disk recording apparatus characterized in that the magnetic disk recording apparatus comprises a writing means for reading and confirming the identification field of the desired sector again, and then recording desired data in the data field of the sector.

[Effect]

According to the above structure, since writing is performed after both side edges of the write track are erased, the side edges of the write track are not erased or scraped, and the track width does not decrease. Furthermore, since only the data field of the sector to be written is erased, and the identification (ID) field is not erased, even if writing is performed using a magnetic disk recording device different from the device that recorded the format, the identification (ID) field will not be erased. ) The side edges of the field are not erased and no reduction in track width occurs.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings.

FIG. 2 shows the main parts of the magnetic disk recording device.

A rotary motor 13 having an output shaft 12 protruding perpendicularly to the base 11 is fixedly mounted on the base 11 . A disk-shaped support 15 is fixed to the output shaft 12 for supporting the magnetic disk 1 such as a hard disk or a floppy disk.
The magnetic disk 1 is rotated at a constant speed by a rotary motor 13 in a plane parallel to the base 11. The magnetic head 16 is positioned along the surface of the magnetic disk 1 between its outer and inner peripheries. That is, a pair of mutually parallel guide rods 17, 17' are supported by a support frame 18 in a plane parallel to the base 11, and the head transfer table 1 to which the magnetic head 16 is fixed is supported.
9 is adapted to be guided along its guide rods 17, 17'. The support frame 18 has a lead screw 20 parallel to the guide rods 17, 17'.
A stepping motor 21 that rotationally drives the head is fixed, and the head transfer table 19 is rotated by
It is screwed together. In order to prevent the feed screw 20 from rattling due to play in the axial direction of the output shaft of the stepping motor 21, the feed screw 20 is urged in the axial direction by a leaf spring 22. When the stepping motor 21 is driven to rotate, the magnetic head 16 is moved in the radial direction of the magnetic disk 1 and positioned at a predetermined location. The stepping motor 21 is a two-phase excitation type stepping motor equipped with two sets of excitation coils. Then, the feed screw 20 is rotated so that the magnetic head 16 moves from one writing track on the magnetic disk 1 to the next writing track by rotation of the output shaft of the stepping motor 21 by four step angles. The pitch is made up of. The magnetic head 16 is configured to be able to move from the outermost "track 0" position of the magnetic disk 1 to the innermost "track 79" position by 80 tracks.

A disk-shaped support 15 supported by the magnetic disk 1
A slit 23 is provided in the circumferential side wall of. A photocoupler 24 consisting of a light emitting diode and a phototransistor is placed between the base 11 and the peripheral side wall thereof.
is placed on top. The photocoupler 24 detects the rotational position of the magnetic disk 1, that is, the index position, by detecting the slit 23 on the circumferential side wall.
Generates an index signal (INDEX).

FIG. 1 is a block diagram showing the circuit configuration of the magnetic disk recording apparatus.

The magnetic disk drive circuit 31 (hereinafter referred to as FDD circuit) is an integrated circuit (hereinafter referred to as an FDD circuit) in which a read circuit section, a write circuit section, a stepping motor drive signal generation circuit section, a modulation/demodulation circuit section, and a logic circuit section are housed in one package. For example, Mitsubishi Electric
M51017AP) is the main element.
The FDD circuit 31 directly drives the coil of the magnetic head 16, and drives the stepping motor 21 and rotary motor 13 via a drive circuit (not shown) made up of power transistors. The FDD circuit 31 is controlled by a magnetic disk control circuit 32.

The magnetic disk control circuit 32 (hereinafter referred to as FDC circuit) is an integrated circuit (for example, Mitsubishi Electric M5W1793-1) in which an interface section, a logic operation circuit section, various registers, etc. are housed in one package.
02P) as the main elements. The FDC circuit 32 is connected to the computer 33 through various control lines such as a data bus and interrupt requests, and controls the FDD circuit 31 based on information from the computer 33.

From the FDC circuit 32 to the FDD circuit 31, a rotation command signal for instructing rotational drive of the rotary motor 13, a direction signal for instructing the moving direction of the magnetic head 16, and a write signal (WD, Write signal) to be recorded on the magnetic disk 1 are sent.
Data), a step pulse signal that instructs the stepping motor 21 to step, and a write permission signal (WG, Write Gate) that enables the coil of the magnetic head 16 to be excited are given. On the other hand, FDD
From the circuit 31 to the FDC circuit 32, signals such as an index signal (INDEX) indicating the rotational position of the magnetic disk 1 and a read signal (RD, Read Data) read from the magnetic head are transmitted.

Among these, the write permission signal (WG) given from the FDC circuit 32 to the FDD circuit 31 has its end extended by a predetermined time τ by the timer circuit 34. The predetermined time τ is 1/5 to 4/5 of the time required for the gap 8 provided between the plurality of sectors 4 formed on one write track 2 to pass over the magnetic head 16. is set to a time in the range of . The predetermined time τ is the resistance 36 and the capacitor 37.
determined by the constant.

FIG. 3 The write permission signal WG1 output from the FDC circuit 32 and the timer circuit 34 extend the FDD
Timing charts of FIGS. 4 and 5 showing the relationship with the write permission signal WG2 input to the circuit 31 are diagrams for explaining the effect of extending the write permission signal, and are diagrams for explaining the effect of extending the write permission signal WG2. 3 is a schematic diagram showing sector 4. FIG.

The FDD circuit 31 excites the magnetic head 16 only while the write enable signal (WG) is input. On the other hand, the FDC circuit 32 outputs the write permission signal (WG) only while outputting the write signal (WD) corresponding to the number of bytes of the data field 7 given by the computer 33. Therefore, if there is a slight rotational fluctuation due to fluctuations in the rotating motor 13,
As shown in FIG. 4, there is a slight difference in the rotation angle of the magnetic disk 1 when erasing the side edge of the data field 7 and when writing data to the data field 7. However, there may be a portion 41 where the previous data is not erased. To solve this problem, timer circuit 3
4 was inserted. By uniformly extending the write permission signal by a predetermined time τ, during the extended time τ, when the write signal (WD) ends, the magnetic head 16 is excited in one direction, and each track is uniformly excited. It will be deleted. For this reason, the fifth
As shown in the figure, an erased portion 42 is added to the end of the data field 7, and extended erased portions 43 and 44 are also added to the erased portions 9' on both sides. Therefore, erasing portions 9' are always formed on both sides of the portion of the data field 7 where data is recorded, and no portion 41 that is not erased occurs. The above added erased parts 42, 43, 44
is absorbed into the gap 8 provided between sectors 4 after the selection of the predetermined time τ, and the ID of the next sector 4 is
It never hits field 6.

Based on the above hardware configuration, a write operation for updating data in a desired sector will be explained.

FIG. 6 is a flowchart showing the actual processing by the computer 33, and FIG. 7 is a schematic diagram showing the data field and erasing section formed as a result of the write operation.

The center positions of each write track 2 are separated by a distance corresponding to four step angles of rotation of the stepping motor 21. On the other hand, the width W of the magnetic head 16, ie, the width W of the track recorded by the magnetic head 16, is slightly wider than the distance corresponding to two step angles. The basic operation of the write operation is, first,
At positions P2 and P3, which are moved by one step angle to the left and right from the center position P1 of write track 2, only the data field portion of the sector to be written is erased, and then the data field part of the sector to be written is erased.
, and write new data to the data field.

When the write process 100 starts, the first step is
At 101, the center position P1 of the desired write track to be written, for example, track 38 in FIG.
The magnetic head 16 is moved to Then step
At 102, the ID field 51 of the sector to be written is read out of the nine sectors of the write track. In step 103, it is confirmed whether or not the ID field 51 of the sector can be read. If it is not possible, the process proceeds to step 120, where an error is displayed and the process is terminated. To determine whether reading is possible, reading is actually repeated several times, and if reading is still impossible, it is determined that reading is not possible.

If reading of the ID field 51 is confirmed, the process advances to step 104. In step 104, the magnetic head 16 is moved to a position P2 at the outer periphery of one step angle.
Then, in step 105, the readout of the ID field 51 is confirmed again. At this position P2,
Although it is shifted from the center position P1 of the ID field 51, more than half of the width of the magnetic head 16 overlaps with the ID field 51, so it is normally readable although the signal level is lowered. In the next step 106, it is determined whether or not reading is possible. If it is possible, the process proceeds to step 107, and the portion corresponding to the data field following the ID field 51 is erased. As a result, the outer half of the data field and the side portion 52 that protrudes by one step angle toward the outer circumference are erased, forming an outer erased portion. If reading is not possible in step 106, the erase process in step 107 is omitted and the process proceeds to step 108.

In step 108, the stepping motor 21 is rotated by two step angles to move the magnetic head 16 to the inner circumferential position P3. And step 109,
110, 111, ID field 51 again in the same way
If the ID field 51 is readable, the data field portion following the ID field 51 is erased, and if it is not readable, the data field 51 is not erased and the process proceeds to the next step.

In step 112, the magnetic head 16 is moved to the outer circumference by one step angle and is positioned again at the center position P1. Then, in step 113, the readout of the ID field 51 is confirmed again, and the next step 114 is performed.
Then, write the desired data in the data field following the ID field, and write the desired data in the data field 5.
4 is updated and the process ends.

In this way, the erasure process is performed first, and the side portions 52, 53 of the inner and outer peripheries of the data field 54 are erased.
After the data field 54 is erased and the erased portion is formed, writing is performed and the data field 54 is formed.
The width of the data field 54 is the same as the width of the magnetic head 16, and the side edges are not cut and the data field 54 is not narrowed.

Figures 8 and 9 show data fields when write processing is performed with another magnetic disk recording device other than the magnetic disk recording device in which the initialization format of the magnetic disk was recorded and each ID field was written. FIG.

If the device is different, the position of the magnetic head 16 will not completely match due to variations in the accuracy of the feed screw 20, etc. Therefore, even if the writing track 38 is positioned at the center position of the same write track 38, the center position P0 of the ID field 51 and the current positioning position P1
The edges may be misaligned. FIG. 8 shows a case where the center position P0 of the ID field and the current center position P1 are shifted by approximately 30 μ (microns). In this case, the position P3 is moved one step toward the inner circumference from the center position P1.
In this case, the overlapping width between the magnetic head 16 and the ID field 51 becomes 1/3 or less, and the signal level drops extremely, reaching the limit of whether or not the ID field 51 can be read. If it is readable, the inner side portion 53 is erased, and if it is not readable, it is left as is without being erased. In any case, only the data field part is erased, so the ID field 5 that was created when recording the format
New data field 5 without removing 1
4 is written.

FIG. 9 shows a case where the center position P0 of the ID field 51 and the current center position P1 are shifted by nearly 50 μ.
In this case, the magnetic head 16 overlaps with the adjacent write track 39 at position P3, and when reading the ID field 51 in step 109, the magnetic head 16 overlaps with the adjacent write track 39.
Since the signal in field 55 is also detected, it becomes unreadable. Then, step from step 110.
112, and the side portion 53 on the inner circumference side is not erased and remains as it is. Therefore, even if such a large deviation occurs, the data in the data field 54 is updated without erasing or scraping the side edges of the adjacent write track 39.

FIG. 10 is a schematic diagram showing a write track on which new data has been written as described above.

The ID field 6 of each sector remains as it was at the time of initial format recording, and the side edges are not scraped by the writing process. The newly written data fields 54 and 55 have their center positions
It may be recorded at a position slightly shifted from the center position of the ID field 6. However, the width of the magnetic head is 1
The width of 6 remains the same and the side edges are not cut. Further, when forming the erased portion 9', the side edges of adjacent tracks are not scraped. When the write track 2 recorded in this way is read out by a different recording device, the magnetic head may be read out by the ID field 6 due to variations in the positioning adjustment error of that device.
Alternatively, the vicinity of the center position of the data fields 54 and 55 is scanned, a signal is detected by the overlapping width portion of the magnetic head 16, the ID field 6, and the data fields 7, 54, and 55, and the respective data is read out. At this time, since the widths of each ID field 6 and data fields 7, 54, and 55 are not narrow, a sufficient overlap width can be obtained, and a sufficient margin for reading signal levels and the like can be obtained.

〔Effect of the invention〕

As explained above, the present invention has the above configuration, and even when recording in a soft sector format using a single gap magnetic head, each sector is first erased and then written. As a result, the width of the write track, including the identification (ID) field, remains the same as the width of the magnetic head, and does not become narrower, dramatically improving the reading margin during reading, and making it easier to read data between magnetic disk recording devices. This has the excellent effect of easily achieving compatibility.

[Brief explanation of the drawing]

1 to 11 show one embodiment of the present invention, FIG. 1 is a block diagram showing the circuit of a magnetic disk recording device, FIG. 2 is a front view of main parts showing the mechanical configuration, and FIG. Timing chart, Figures 4 and 5 are schematic diagrams showing tracks, Figure 6 is a flowchart showing actual processing, and Figures 7 to 10 are schematic diagrams showing data field sections updated by write processing. 11 are plan views schematically showing the structure of tracks formed on a magnetic disk, and FIG. 12 is a schematic diagram showing a write track formed by a conventional apparatus. 1...Magnetic disk, 2...Writing track, 4
... Sector, 6, 51 ... Identification (ID) field, 7, 54 ... Data field, 8 ... Gap, 9 ... Erase track, 9' ... Erasure section, 1
6...Magnetic head, 21...Stepping motor, 31...Magnetic disk drive (FDD) circuit,
32...Magnetic disk control (FDC) circuit, 33
...computer, 34...timer circuit.

Claims (1)

[Claims] 1. Writing that records a desired information signal on a magnetic disk by a single-gap magnetic head positioned along the surface of the magnetic disk between its outer and inner circumferences. In a magnetic disk recording device in which tracks are formed, the magnetic head is moved from the center position of a desired write track to one side edge position, and after reading and confirming the identification field of the desired sector of the write track, a first erasing means for erasing the data field portion of the sector; then moving the magnetic head from the center position of the write track to the other side edge position and reading the identification field of the desired sector again; After checking,
a second erasing means for erasing the data field portion of the sector, and then moving the magnetic head again to the center position of the write track and reading and confirming the identification field of the desired sector again; A magnetic disk recording device comprising: a writing means for recording desired data in a data field of a sector. 2. If the reading of the identification field cannot be confirmed in the first or second erasing means, the writing means is executed without erasing the data field portion in the erasing means. A magnetic disk recording device according to claim 1.