JPH0476866A - Disk device - Google Patents

Abstract

PURPOSE:To easily execute the digital recording of audio signals by a user by providing the plural kinds of compressed encode processing modes in advance and selecting readily a desired mode from these modes. CONSTITUTION:A detector 101 detects whether an inputted signal form is an analog signal or a digital signal. The analog signal is sent to a compressed encoding part 120 after A/D conversion, and the digital signal is directly sent to the part 120. In this case, the audio signal is converted to the digital signal of the bit rate of 256Kbps or 128Kbps and sent through a memory manager 140 to a buffer memory 150. The data of this memory 150 is recorded in a disk. On the other hand, the data read out of the disk is sent through the memory 150 and the manager 140 to a decoding part 130. In this case, for the compressed encoding part 120, the mode of either 256Kbps or 128Kbps is selected by a host CPU 160.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a disk device that stores audio signals as digital signals.

(Conventional technology) Currently, there are two mainstream digital audio media, due to performance time and other factors: CDs (compact discs), which are playback only, and DATs (digital audio tapes), which can be recorded and played back. It becomes.

A CD digitally records audio signals in the form of pits on a polycarbonate substrate with a diameter of 12 ann. The track pitch is 16 μm and the linear density is 43 kbp, which is an extremely high recording density, and it is possible to record stereo audio signals with a frequency of 20 to 20 kHz+ for about 60 minutes. The sampling frequency is 44. IkHz, quantization number is 1
It has a 6-bit error correction code with approximately 30% redundancy.
The transmission rate is approximately 2 Mbps.

DTA (digital audio tape) is a CD
It was introduced as a recording and playback media that compensated for the inability to record. An 8mm metal tape is housed in a small cartridge with a similar structure to a VTR, and tracks are formed diagonally on the tape using a rotary magnetic head, just like Hit and Th. Track pitch is 13.6μ
The m1 line recording density has an extremely high recording density of 61 kbpi, and the frequency is 20 to 20. KH! It can record 120 minutes of stereo audio signals.

In addition to these two media, there are three types of media used in computers, word processors, electronic musical instruments, etc., although their capacity is small.
, 5' floppy disk (35'FD). The disc size is 86mm in diameter and the cartridge size is 9.
It measures 0 mm x 94 mm x 3 mm, and has a shutter in the area where the magnetic head touches to protect the medium when it is not in use. The currently popular 3 and 5' FDs are 2DD and 2HD using CO-γ media, and their unformatted capacities (iN capacities) are IMB.

It is 2MB. Recently, 2ED (UF capacity 4MB) using Ha Mitsuerite direct recording medium has also been commercially available, and 3
The capacity of 5'FD is rapidly increasing. These FDs have a track density of 1351 pi (racking servo is not used) and a linear recording density of 35 kbpi for 2ED.

These drive devices have read/write compatibility with the lower FD. Furthermore, recently, large-capacity FDs with a tracking servo (sector servo in most cases) is used for FDs, increasing the track density by four times compared to conventional ones, and increasing the format capacity (FT capacity) to more than IOMB. being developed.

With the spread of CDs, digitization of audio signals is becoming commonplace. Naturally, the voice of users who want to easily record audio signals digitally is growing louder, but today's CD, DAT, or 3
．． 5' FD does not fully respond to this user's voice. In other words, current media are limited in size, ease of handling,
Resistant to dust, scratches, and rough handling, easy to carry,
This is because they do not have enough performance and functionality to fully satisfy users in terms of recording functionality, random access functionality, repeated durability, recording time, price, etc.

Although CDs are excellent as a source of high-quality digital sound, they have the essential drawback of not having a recording function. Also,
There are also problems with size, ease of handling, portability, price, etc. In particular, since it is not in a cartridge, it is difficult to handle and remove from the case, and there are problems such as protection against dust, scratches, rough handling, etc., so anyone from children to the elderly can easily use it. It's not something that can be done.

Furthermore, the current situation is that it is extremely difficult to use them for car audio or handheld devices.

In this way, CDs are merely an alternative to LP records, and cannot be called a secondary digital audio media.

Although DAT compensates to some extent for the disadvantages of not being able to record CDs and the disadvantages of being difficult to handle, there are also problems such as copyright issues and high cost of digital copying.
There is no sign that it will become widespread. The essential problem with DAT is that it has poor repeat durability and random access.
Due to the incomplete cartridge structure, it has extremely poor protection against dust, scratches, and rough handling. In particular, DAT's imperfect cartridge structure has many problems as a popular audio medium, such as the tape being easily pulled out and destroyed by children.

On the other hand, the 3.5' FD is packaged in an affordable cartridge, so it is easy to handle, has excellent repeated durability and random access, and has the advantage of being inexpensive. However, digital recording of audio signals has a problem of low capacity. For example, a recently developed large-capacity FD (storage capacity is about 12.5 megabytes) is equipped with the same digital signal as a CD (stereo signal, sampling period 4).
If you try to record 4.1kL, quantization number 16 bits), you will only be able to record for about 70 seconds. 3.5'
Other problems with the FD are that there is a gap near the chucking hub, which is incomplete for dirt to enter, and that there is a strong possibility that dirt attached to the nyatter opening/closing part will fall onto the disc with the shutter. Since there is no locking mechanism, the media can be easily exposed and damaged.

(Problem to be solved by the invention) However, the 3.5' FD as mentioned above has various problems, and especially when recording digital audio signals on the FD, it is said that it can only record for about 70 seconds. Another problem is that even if it were possible to record several minutes, the user would not be able to arbitrarily control (select) the quality of the recording.

The present invention has been made to solve the above-mentioned problems, and aims to provide a disk device that allows users to easily digitally record audio signals.

[Structure of the Invention] (Means for Solving the Invention) The present invention provides a disk device that compresses and encodes input digital data and records the compressed and encoded data on tracks of a disk. A plurality of types of processing means are provided in advance, one of the plurality of processing means is selected, and information indicating the type of the selected processing means is recorded on the track of the disk together with the data compressed and encoded by this processing means. This is a disk device characterized by recording data on a disc.

The disk device further comprises two heads that divide digital data of a predetermined length into two and record each divided data on the top and bottom surfaces of the disk. This disk device is characterized in that each trough is divided into a plurality of sectors, and for tracks having the same number of sectors, the disk is rotated at the same number of rotations.

(Function) In the present invention, input digital data (audio signals) are set in advance into a plurality of compression encoding processing modes (for example, 256 kbps mode, 12 Hbp+ mode, etc.), and the user can arbitrarily select a desired one from among these modes. Since the configuration allows the mode to be selected depending on the input data, it is possible to effectively utilize the recording capacity of the disc.

(Example) Hereinafter, the present invention will be described in detail based on an illustrated example. First, before explaining the system, the structure of a floppy disk cartridge according to the present invention will be explained using FIG. Figure 1 shows the state where the shutter is open, Figure 1 (a) is a plan view, Figure 1 (b) is a side view, Figure 1 (
c) is a rear view.

1i and Ib are shells of the cartridge, which are molded from resin such as vinyl chloride, and are fused together after housing the floppy disk 2 therein. The size of a floppy disk is 94 mm in diameter.
Kaku, the size of the cartridge that stores this is 911+a
m x 1G2 m x 4-, and if you put it in a plastic hard case (not shown), the width will be A4 size, which is almost the same as a paperback book. The case is 105 mm x 106 mm x 9 mm. However, if you use a book case, it should be the case size or smaller. If it is the same size, the disc can be made a little larger). A shutter 3 has a window 3a for loading a magnetic head in a plan view. 3b shows the side surface of the magnetic head, and by cutting the portion 30, the height of the magnetic head can be made lower than in the case of a 3.5' FD, even though the cartridge is thicker.

48.4b is a window for loading the magnetic head, 18
It has a width of -, and can accommodate not only the magnetic head but also the entire magnetic head arm, which is effective in making the drive thinner. 15 is a window for chucking, diameter 1
It is 81ml/l. 5a and 5h are grooves provided in the shell to move the shutter 3, and the upper surface of the shutter is set so as not to exceed the highest surface of the shell. 6 is a protrusion of the shell provided in the shutter window a, and is provided to prevent dirt accumulated in the groove of the shell 5a from being scraped onto the disk surface at the part 3a when the shutter 3 is opened. be. 7a and 7b are bridges for reinforcing the cart run, and have approximately the same thickness (1.5 to 2 holes) as the shutter 30.

Reference numeral 8 denotes a shutter lock mechanism, which has a spring property, and enters into the cartridge when it hits a shutter opening/closing pin (not shown). 9 is shutter 3
In the closed state, the shutter 3 is fitted with a protrusion 10 provided on the shutter 3, so that even if the shutter 3 is pulled, the shutter will not open. Reference numeral 11 denotes an α-shaped spring provided at 12 of the shutter 3 between the protrusion and the inner wall of the cartridge, and always pushes the shutter in the closing direction. 14a and 14b are grooves for sliding the shutter, and are fitted with 13a and +4b, respectively. To open the shutter 3, a shutter opening/closing pin (not shown) pushes the shutter locking mechanism 8 at position 23. Actually, when the cartridge 1 is inserted into the drive, the shutter opening/closing pin provided in the drive pushes the shutter locking mechanism 8 at the position 23, and the locking mechanism is released.

When the cartridge is further pushed in, the shutter opening/closing pin presses the shutter 3 while resisting the spring 11, and finally enters the fixing groove 24 of the shutter opening/closing pin, leaving the shutter in an open state as shown in FIG. On the other hand, when the shutter opening/closing pin is removed from the groove 24, the shutter 3 begins to close with the force of the spring 11, pushing the locking mechanism 8 and causing the protrusion 10 to open 9.
The shutter enters the groove and becomes locked. At this time, the shutter 3 opens the window 4 for loading the magnetic head.
8.4b and the window 15 for chucking are completely closed to prevent dust from entering.

Figure 2 shows how the disk is chucked, and is seen from the A-^ cross section in Figure 1(c).
In figure (C), the spindle shaft side is not shown). 3.
The 5' FD uses a chucking method using a spindle shaft and a drive pin. If this method is used, the window becomes too large due to the chucking hub, and it is difficult to completely cover it with a shutter. Another problem is that no driving force is produced unless a load is applied to the disk, and that small fluctuations in the circumferential direction occur due to load fluctuations. Therefore, here, on the premise that the tracking servo method is used, chucking is performed by fitting with the spindle shaft and by the attraction force of the magnet. 16 is a flange-shaped chucking hub made of resin such as polycarbonate,
The hole 17 for fitting with the spindle shaft and the magnetic material +8 for magnetic chucking (25 is for maintaining strength) are made by body molding. Using this method, there is a distance of 10 mm between the hub and spindle shaft 30.
Eccentricity on the order of μm occurs, but it is smaller than the primary mode and secondary mode caused by anisotropic expansion and contraction due to the temperature and humidity of the disk, and this eccentricity is fully tracked by the tracking servo and is not a problem at all. It won't happen. Numeral 31 is a chucking cup, and 32 is a magnet, which attracts 18 magnetic bodies (plated iron plates) and performs chucking. At this time, the tip of the spindle shaft 30 hits the sliding plate 29 and pushes up the top surface of the cartridge shell a little, causing the disk 2
makes it easy to rotate. Adhesion between disk 2 and hub is as follows:
This is done on the flange part of the knob. In addition, the entire disc is sandwiched between liners 30a and 30b, which are provided to remove dust and prevent the surface of the disc from touching, but since there is very little dust entering the disc compared to a 35'FD, the disc can be removed by a lifter or the like. There is no need to pinch it tightly. Therefore, there is an advantage that the load on the spindle motor can be reduced accordingly. 28 is a liner provided between the flange 27 of the knob 16 and the cartridge shell, which prevents the hub from hanging down and helps the shutter 3 to open and close smoothly.

When separating the disk from the spindle shaft 30, the entire cartridge 1 is lifted. The knob and force/yp are in contact with each other while being attracted by the magnet 32, but if you lift it up even harder, the flange 27 of the hub will strongly hit the shell, and it will be released from the attraction force of the magnet 32 and will come into contact with the hub. The cups will separate and the disk will be separated from the spindle axis 30. Therefore, even when chucking is performed using a magnet with strong adsorption force, no load is applied to the bonded area between the disc and the knob, so the bonded area will not be damaged.

Note that the above example of the knob is shown for the case where it is manufactured from resin, but it may also be manufactured from a metal plate such as an iron plate.

Further, even if the size of the cartridge is smaller than that of the embodiment, it can be handled in the same way.

19a and 19b are hole and slide switches for write protection, 20a%2 (lb is a recess for attaching a label, 21a and 21b are cartridge and slide switches)
The hole 22 for positioning the cartridge is an arrow indicating the insertion direction of the cartridge.

Next, I will explain the high-density recording of floppy disks and the disk format.

As a digital audio source to be stored on a floppy disk, a storage audio encoding method that is currently being considered for international standardization is used (bi-sotorate: 256
kbps), recording time is 60 minutes, the storage capacity of the floppy disk is 115.2M/(items).Assuming the disk format efficiency is 60%,
Unformat (UPI capacity is 192MB.

The recording area of the above floppy disk is 1 side, t = 22vm ~ 42mm (T = 2 for side 0)
3.5 to 435), and the linear recording density was 70 kbpi (
If the (1,7) code is used as the modulation method, the recording density on the disc will be 52.5 Hci), and if the format sector capacity is 512 bytes, the number of sectors at the innermost circumference will be 56. If we use a block CLD method in which the number of sectors at the outermost periphery is 107 (linear recording density is constant within the block), the number of tracks required to secure the above capacity is 1400 per surface, and the track density reaches approximately 17,781 pi. At this time, the track pitch is 14.3 μm, the rack width is 11.4 μm,
The allowable off-track due to tracking error is approximately ±1 μm. Track runout, which causes tracking errors, has a primary mode (eccentricity) and a secondary mode.
The former is caused by chucking misalignment, eccentricity of the spindle motor, eccentricity of the disk, etc., and its size is 15 μm above fishing.
The latter m1 occurs due to anisotropic expansion and contraction of temperature and humidity of the disk medium, and its size is ±10 to 15 μm. Therefore,
In the tracking A-ho system, the servo system is designed to ensure tracking performance for the secondary mote. If the tracking error for the secondary moat is ±0.5 μm, then the gain of the servo system is required to be 30 or more. If the sector surf system, which is often used for large-capacity FDs, is used, the number of servo information will be 56 per round, but with this, a gain of only about 10 can be obtained for the secondary moat.

Therefore, in the present invention, a sample servo method (sector servo is also a type of sample servo method) in which two pieces of servo information are embedded per sector is used, and a gain four times as large as sector servo can be obtained in principle. Further, in the present invention, a pre-erasing magnetic head is used to counter overwrite noise and unerased track noise. Figure 3 is a diagram showing the vicinity of the gap, where 40 is the R/W gap, and 4 on both sides of it.
1a.

41b metal film is formed (usually referred to as an MIG head), and is suitable for recording on vertically aligned high Hc Ba ferrite media and metal media. Gap length is 027μm
, the gap width is 11.4 μm. 42 is an erase gap, the gap length is 2 μm, the gap width is 143
It is μm. 43 is a ferrite core, and 44 is a separation membrane for both heads. The shorter the interval (1) between both gaps, the higher the format efficiency, but if it is too short, the head efficiency will decrease. Here, the gap interval is 18
0 μm is selected, which corresponds to 62 bytes on the disk format.

FIG. 4 shows an example of a track format when a pre-erasing magnetic head is used and servo information is embedded in two sectors in one sector, and shows an example in which the user can perform formatting. Traditionally, floppy disks and hard disks using the sector servo system
A sector mark and servo information are embedded at the beginning of the ID field. In this case, an invalid area is generated after the ID field due to the use of a pre-erasing magnetic head, and as density recording becomes higher, formatting efficiency decreases. Therefore, in the present invention, by embedding the sector mark and servo information after the ID field, the above-mentioned wasted area is effectively utilized to improve format efficiency. Note that here, the rotational fluctuation of the disk is ±1
The format is created as less than %.

50 indicates one sector of the track format, the sector capacity is 852 bytes, and the data capacity is 512 bytes. The sector mark field 53, servo field A54, and servo field B57 are recorded in advance by a servo writer. Of these, the servo information recorded in the servo field is 0.5
Tracks are shifted and recorded. 51 is a PLL signal for reading the ID field, which is recorded simultaneously with the ID field during formatting. The ID field is double-written as 10 to ensure reliability of the 10 data. 55 and 58 are PLL signals for reading data field A56 and data field B59, which are recorded simultaneously with the data field. In addition to 512 bytes of data, the data field has 98 bytes added as a correction code using the same LDC method (5 interleave) used in optical discs to ensure data reliability. 60 is IsG (inter-sector gap), which is for absorbing disc rotation fluctuations and data field B ride recovery time. 53 is the sector mark field, WRG61
(Used to absorb disk rotational fluctuations, manufacturing errors in the gap interval of the pre-erasing magnetic head (±lOμm), and write recovery time of the ID field 52)
, 5YNC62ERASE63AGC64 (used for sector mark detection and AGC signal). If the user does not format, WRG 61 is dependent. Further, in this case, even if the sector mark field 53 is moved before the PLL 51, the formatting efficiency hardly changes.

The servo field A54 is embedded in the invalid area created by the advance erase type magnetic head, and is
．． 2ONEIi6. Consists of PO5B67 and GAP68. Two-phase burst position information (4-track period) for obtaining a speed control signal used during seek is formed in PO5A. When data is written, DC erasure by the erase gap is performed immediately after reading the AGC signal, but the transition recovery time is absorbed by PO3A. 2ONE66 has an index signal (disk - one signal per revolution), a sector zone signal (- represents tracks with the same number of sectors per revolution),
A data zone signal (representing the track on which data is recorded) is formed as a burst signal. POSB67
is precise position information used for position control, and an X burst signal (front) and a Y burst signal (rear) are alternately formed for each servo track. The GAP 611 is for absorbing manufacturing errors in gap spacing, rotational fluctuations, etc. of the advance erase type magnetic head.

The servo field B57 is provided in the data field in order to improve the tracking performance for the track runout of the disk, and is used in WRG69. PO5B70. Consists of GAP71. WRG69 is for absorbing the ride recovery time of data field A56, and PO3B7Q is formed with the same precise position information as PO3B67.
It is made longer than PO3B67 in consideration of rotational fluctuations.

The GAP 71 is for absorbing manufacturing errors in the gap interval of the advance erase type magnetic head.

In the track format shown above, considering that the floppy disk used here has an extremely high recording density that has never been seen before, the ID section is double written, the data is added with the same strong ECC as optical disks, and the servo information is This ensures reliability by forming bursts of sufficient length. Furthermore, it is also possible to determine an error in the IDE from the index signal and sector signal.

Furthermore, the AGC signal can be obtained not only from the AGC 64 but also from the addition signal of the X burst signal and Y burst signal of precise position information.

In addition, if the recording density is not as high as in the embodiment, ID,
It is possible to create a track format that increases format efficiency by allocating fewer bytes to ECC, servo, etc.

Next, the play stem of the present invention will be explained.

FIG. 5 shows a block configuration of the player system of the present invention, including an input section 100, an output section 110, a compression encoding section 120,
Decoding unit 130, memory manager/layer 1451 buffer memory 150, host μP 16U, drive controller +70. It consists of a drive 180. The input section +00 has input terminals for analog signals and decimal signals, and the detector +01 detects whether the input signal is an analog signal or a digital signal.If the input signal is an analog signal,
A D converter 102 digitizes and outputs it. After the analog signal is converted to D/D, the digital signal is sent directly to the compression encoder 120. The audio signal is now converted into a dental signal with a hit rate of 256 Kbps or 128 Kbp+ and is sent to the memory manager 14.
0 to the buffer memory 150. The memory manager 140 manages the buffer memory +50 and the input/output of signals. Host h CPU16
0 sends an instruction to the disk controller and memory manager to record the data in the buffer memory on the disk according to the drive status. On the other hand, the data read from the disk is stored in the buffer memory +50 and then sent to the decoding unit 130 via the memory manager 140, where it is restored to the original digital audio signal and then output to the output unit. 110 and output as an analog or digital audio signal.
Selected from 60. The user can give instructions to the host CPU] 60. An area is provided on the disk to store which mode is selected, and processing corresponding to this data is performed during decompression and decoding.

It is preferable that the mode data be partially recorded in the data field A56 in FIG. Recording time is 60 minutes in 256Kbps mode/double-sided, 1 in 128Kbps mode
2i 1 minute/both sides. Moreover, the compression mode is not limited to two, but can be set to three or more, or can be set arbitrarily by the user.

Here, the case is shown where all the data to be recorded on the disk is compressed and encoded, but it is also possible to directly record the analog signal after A/D conversion.

The recording time at this time is approximately 11 minutes in the case of a CD wave digital signal.

If an uncorrectable error occurs in the data in the tracks on either disk surface, the data from the tracks on the disk surface with no errors is used to digitize the specified length. It may also have a function of reproducing a series of signals and notifying this information to the outside when the size of the error exceeds a predetermined size.

Furthermore, tracks on the disk with the same number of data sectors are rotated at the same rotation speed, and the hit rate of each track on the disk is compared to the bit rate when the analog signal is digitized. It may be configured to include a spindle motor that rotates at a rotation speed that is twice or more faster.

In a disk cartridge of a disk device that records or plays back by digitizing analog signals, the loading window of the screen head and the chucking hub window are covered with a shutter having a locking mechanism, and the shutter opens and closes. A cartridge shell that is formed higher than the shutter, and a hole in the center that fits the spindle shaft, at least one end surface is made of a magnetic material, and the other end surface is larger than the previous end surface. a flange-like chucking hub, which has a diameter and is bonded to the disk on this surface, the end surface to which the disk is bonded is formed larger than the chucking window of the shell, and the part of the shell that contacts the flange-like hub. A liner may also be provided.

When recording data in sector units using a pre-erasing head, servo information is formed in two or more locations in one sector, one of which may be located directly in the ID field. etc. can be used in various ways.

Note that in the above example, the storage of an audio signal has been described, but a video signal from an electronic still camera may also be stored.

As described above in detail based on the embodiments, in the present invention, a floppy disk is housed in a cartridge that is completely sealed including the window for chucking. The shutter or part of the shell near the window that opens and closes is made higher, and the shutter is also equipped with a locking mechanism to prevent dust from entering or accidentally damaging the media. Furthermore, the size of the cartridge is approximately A6 size (paperback book) when the cartridge is housed in the case. Therefore, the floppy disk of the present invention has excellent size, ease of handling, resistance to dust, scratches, rough handling, etc., ease of carrying, and storage stability, and can be easily used by users.

On the other hand, with the present invention, we have achieved a large capacity floppy disk by using a pre-erasing magnetic head, a sample servo, and a linear recording density that is approximately constant. By using the storage audio encoding method (128Kbps to 256Kbps+), the recording time of 6 floppy disks is reduced.
The recording time ranges from 0 to 120 minutes, which is comparable to the audio cassettes currently in use (the recording time would be approximately 11 minutes if it stored digital signals comparable to those of a CD). In addition, it has the advantage of being extremely easy to use compared to data type disks because it has excellent random access and repeat durability, which are characteristics of floppy disks.

As described above, by using the floppy disk and its player system of the present invention, audio signals can be easily digitally recorded or played back and enjoyed, and they are also easy to carry and store. It also has the advantage of being as easy to use as traditional cassette tapes for things like car audio, which conventional digital audio media are not good at. In addition, since the floppy disk of the present invention does not store digital sources such as CDs in their original form, it has practical effects such as being less prone to copyright problems, which were the problem with DAT. is extremely large.

[Effects of the Invention] The small recording capacity of disks such as co-floppy disks can be utilized extremely effectively.

Also, to digitize a track format that has not yet been completed, a series of signals of a predetermined length can be transferred to side 0 of the disk.
A method of recording by dividing the disc into tracks on one side (upper surface) and one side (lower surface) will be described below. A series of signals of a predetermined length digitized by the compression encoder 120 shown in FIG. 5 is divided into two parts by the memory manager 140 and recorded in tracks on side 0 and side 1 of the disk.

In this case, the data to be recorded on side 0 and side 1 are recorded by positioning each bet.

Conversely, the data thus divided and recorded on each side is integrated by the memory manager 140, returned to the original data, and decoded by the decoder +30 for output.

[Brief explanation of the drawing]

FIG. 1 (aL (bl, ((r) is a diagram showing the configuration of the disk cart of the present invention. 1... Cartridge 2... Floppy disk 3...
...Shutter 6...Dust-proof protrusion 8...Shutter lock mechanism 16...Chucking hub 43...Advance erase type magnetic head 50 track format 52...ID field 54.57...Surho field 56, 59 Data field 120...Compression encoding section 130 Decoding section 180 Drive representative patent attorney Norichika Kensuke 1b Fig.

Claims (5)

[Claims] (1) In a disk device that compresses and encodes input digital data and records the compressed and encoded data on tracks of a disk, a plurality of types of processing means for the compression and encoding are provided in advance, and the plurality of means for selecting one of the processing means; and means for recording information indicating the type of processing means selected by the processing means on a track of the disk together with the data compressed and encoded by the processing means. A disk device comprising: (2) In the disk device according to claim 1, means for dividing digital data of a predetermined length into two, and two heads for dividing and recording each data divided into two by this means on an upper surface and a lower surface of the disk. A disk device comprising: means. (3) A disk device according to claim 1, wherein each track of the disk is divided into a plurality of sectors, and for tracks having the same number of sectors, the disk is rotated at the same number of rotations. (4) The disk according to claim 2 is housed in a disk cartridge, and the cartridge is connected to a loading window for loading the two heads and a hub window for chucking the disk using a shutter having a locking mechanism. a cartridge shell in which a part of the part where the shutter opens and closes is formed higher than the shutter; a hole in the center of the disk that fits with the spindle shaft; and at least one end surface made of a magnetic material. a flange-like chucking hub, the other end surface of which has a larger diameter than the end surface and is bonded to a disk at this surface, and the end surface to which the disk is bonded is formed larger than the chucking window of the shell; , and a liner provided on a portion of the shell that comes into contact with the chucking hub. (5) The head according to claim 2 is a pre-erasing head, and data is recorded in sector units, and servo information is formed in two or more places in one sector on the track on which data is recorded, and one of the servo information is formed in two or more places in one sector. is located immediately after the ID field.