JPS61175968A - Information recording and reproducing device - Google Patents

Abstract

PURPOSE:To control easily recording or reproduction, also to make a recording density high, and to shorten an access time by making a recording or reproducing speed different in an area consisting of plural tracks and an area which is different from said area. CONSTITUTION:A reproducing clock generator 10 is constituted with so called a P.L.L circuit, but recording/reproducing clock rates of the innermost peripheral track group T4 and the outermost peripheral track group T1 are are separated by about two times, and in a usual P.L.L circuit,it is difficult to lock stably to an object frequency in this range. Therefore, when an address is designated at the time of the reproduction, a frequency selecting signal corresponding to the address is generated from a controller 1 in the same way as the time of recording, any one frequency among f1-f4 is outputted as the comparison frequency of a reproducing clock generator 10, to the reproducing clock generator 10 through an AND gate 4 and an OR gate 5, and the center frequency of the PLL is varied suitably. By a reproducing clock which is obtained in such a way, a binary-coding output signal outputted from a comparator 9 is sampled by a demodulator 11, by which a recording data bit train (...1,1,0,1...) is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an information recording and reproducing apparatus, and particularly to an apparatus for recording and reproducing information on a disk-shaped recording medium.

[Prior art]

Conventional devices of this type include devices using magnetic disks, optical disks, magneto-optical disks, etc., and an optical disk device will be described below as an example.

When recording information on an optical disk that rotates at a constant angular velocity, the minimum bit diameter is limited by the beam diameter of the laser beam used for recording and reproduction, and this is the disk with the slowest linear velocity in the track direction. The conditions are the most severe at the innermost circumference of the disc, and the transfer rate of recorded data is determined by the bit diameter and rotational speed at the innermost circumference of the disk. In this case, the recording density decreases toward the outer circumference of the disk, and as a result, in the constant angular velocity disk, the recording capacity per surface of the disk is not optimized.

On the other hand, as a method to prevent the above-mentioned drawbacks, the recording density can be improved by optimizing the linear velocity considering the bit diameter and rotating the disc-shaped recording medium so that the linear velocity in both directions is constant on the disc surface. In order to maximize the recording capacity per disk surface by keeping it constant on the disk surface, the so-called C
L-V・(Con5tantLinear Velo
city) method.

However, in this method, the number of rotations of the disk must be changed in the radial direction of the disk so that the linear velocity in the track direction is constant.

It takes a lot of time to control the rotation of the disk when the angular velocity is constant, so-called C, A, V.

(Con5tant Angular Velocit
y) has the disadvantage that the access time is longer than that of the method.

〔the purpose〕

SUMMARY OF THE INVENTION The present invention was made in view of the above points, and it facilitates recording or playback control by differentiating the recording or playback speed between an area consisting of a plurality of tracks and an area different from the area. It is an object of the present invention to provide an information recording/reproducing device with high recording density and short access time.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a track or sector format on a disk surface. T1 t T2 tT3
．． T4 indicates a truck group, and within each truck group,
The data recording sections 81 to Sn of each sector are recorded at the same recording frequency, and therefore the data is sampled and the recorded data is reproduced according to the reproduction frequency based on the recording frequency.

For example, the data section is recorded at 11 frequencies on the outer periphery of the disk, on the T1 track group, and in the same way, on the inner periphery of the T2) rack group, 12 frequencies are recorded, and on the T3 track group, 13 frequencies are recorded.
In the innermost circumference T4 track group, recording drops at each of 14 frequencies. Of course, the order of frequency is fX > T2 > T3
> T4, and by doing so, the recording density on the disk surface can be roughly optimized. In the header portion at the beginning of each sector indicated by diagonal lines on the disk surface of FIG. 1, address signals, sector information, etc. are recorded in a flash format at the same frequency, for example, the fo frequency. This disk is a disk that rotates at C, A, and V as described above, and due to the beam diameter limitations of the recording/reproducing light beam, the innermost track, group ', T4,
The fo frequency is determined by a certain bit diameter, and therefore -
The relationship is approximately fo z fa (T4) data recording frequency of the rack group). As shown in Fig. 1, the outermost track group Tl is composed of sectors S, , Sl...8n, and is formatted so that n+1 sectors are formed per track.T2) Rack The group is composed of sectors SO, sl...s n-m, and has a format of (n-m + 1) sectors/tra. However, n and m are positive integers. T,,T4
) The same can be said for the group T4, and the number of sectors in the innermost track group T4 is approximately 1/2 of the number of sectors (fl+1) in the group T1, the outermost track group. This is because the recording/reproducing performance of the disc is optimized when the recording range of the disc is between 1/2 and 2/2 of the radius.

For example, considering a disk with a diameter of 200 mm, the radius is 1
00 mm, the outermost recording track may be set near the 94th track, and the innermost recording track may be set near the 54th track. Then T1: 94-84 kaku, T2: 84-74 kaku, T3 near 4
〜64 閤, T4: Divide the tiger group like 64〜54 鬬. The innermost track in each track group is the most severe in terms of spatial frequency, so the innermost track is 7 ohms,
I'll decide on the tiger. For example, if the minimum recording pit length is 1.27 μm in the track direction, 1 sector is 1010 bytes, and the recording modulation method is MFM, then for T4 track, the innermost track of the group, track length = 2 πX54M = 339292 μm...・
(1) becomes. Also, the length required to record 1 byte is 1.27 μm x 8 = 10.16 μm...
...(2) becomes. Therefore, the length of the sector is 10.16 x 1010 = 10.26 mm...
”・(3). Therefore, the number of sectors per track is (1) divided by (3) and becomes 339292 μm/10.26 mm = 33 sectors/track. Therefore, in the T4 track group, there are 33 sectors/track. It becomes the composition.

Similarly, for the T3 tiger group, 2 z x 64 mrn/10.26 mm = 39
Sectors/traces, but since the ratio occupied by a portion of the header of one sector increases toward the outer periphery, the net number of sectors decreases accordingly. Correcting this will reduce the number by about 1 sector, resulting in a net of 38 sectors/track. Therefore T3
The track group has a configuration of 38 sectors/track.

Similarly, in the T2 track group, 2π×74 mm/10.26 mm=45 sectors/track, which is modified to have a configuration of 43 sectors/track.

Similarly, in the T1 track group, the structure becomes 2π×84 sectors/10.26 mm=51 sectors/track, which is modified to have a configuration of 48 sectors/track.

If the pitch between 10,000 tracks is 1.6 μm, each track group has a 10 mm area of 10 mm / 1.6 μm = 6
250) Since the rack is configured, each track group T1
The total number of sectors is calculated from the number of sectors accommodated in T4 as follows.

(33+38+43+48)x 6,250=1,01
2,500 sectors/plane If we assume that the user's byte of one sector is 512 bytes (hereinafter referred to as B),
The user's byte per side is approximately 518MB/side (M
B=106B).

In the process of calculating the number of sectors for one track in the above calculation, fractions were removed and the number of sectors was determined as an integer number. The remainder can be allocated to gears, gears, etc. between sectors. Also, the number of bytes that the user can record out of 1010B/sector is set as 512B, but the remaining part is used for hard error correction, and the remaining part is used for powerful error correction, but it will not be described in detail here.

On the other hand, if the entire surface is recorded in 7 ohm and T4 on the 14th group of tracks, it will be a C, A, V entire recording method, but the recording capacity of the entire surface will be (33 + 33 + 33 + 33) XS, 250 = 825,0
Therefore, the user's byte per side is 512B x 82 (000=422MB/side).

Therefore, in the recording method of this embodiment, the recording capacity can be increased by 518/422=1.23, that is, 23%, compared to the C, A, and V methods.

The recording sequence of the disc shown in FIG. 1 will be explained below using FIG. 2. In Figure 2, 1 is a disk controller, 2 is a multiplexer, and 0. First, during recording,
By the address number specified by an external device (not shown), that is, the address is T1* of the disk.
A 2-bit encode signal is generated from the controller 1 and input to the multiplexer 2 depending on which region of T2 t T3 r T4 it is in. Multiplexer 2 receives its 2-bit signal 00. One of the AND gates 4 is selected according to Of, 10.11. 3 is a signal generator that generates signals of frequencies fl-fz, J'a, and T4, and has four built-in oscillation circuits using, for example, known crystal oscillators. One frequency is selected from ~f4. The output of the gate 4 is input to the OR gate 5, and this output becomes the basic tarokk 21 for recording, is sent to the controller 1, is used to read the recorded data 2o, and is input to the variable 11486 at the same time. The modulator 6 contains the recording data 20 from the controller 1 and the recording basic clock signal 2.
1 is input, mixed and modulated by 1, outputted to the laser driver 7, and information is recorded by the light beam modified w1.

FIG. 3 is a block circuit diagram of the reproduction system portion of this embodiment. 8 is a playback preamplifier, and its analog output signal is 9
It is binarized by the comparator circuit. 10 is a reproduction clock generator that generates a reference clock for demodulation and reproduction from this binary signal, and 11 is a demodulator that samples the binary output signal of 9 with the reproduction clock signal to obtain a bit string of recording data. be.

The operation will be explained below. Regeneration clock generator 10
is composed of so-called P, L, and L circuits, but as in the case of this embodiment, the recording/reproducing clock rate of the innermost track group T4 and the outermost track pT1 is approximately doubled as described above. They are located close to each other, and it is difficult to stably lock onto the desired frequency in this range using a normal P, L, L circuit. Similarly, a frequency select signal corresponding to the above address is generated from the controller 1, and the AND gate 4. Through the OR gate 5, one of the frequencies f and -f4 is outputted to the reproduction black and white generator 10 as a comparison frequency for the reproduction black and white generator 10, and the PLL
The center frequency of can be changed appropriately. The reproduction clock obtained in this way is used to output 2 from the frequency converter 9.
A demodulator 11 samples the digitized output signal.

By doing so, a recording data bit string (...1,1°0.1...) is obtained.

The above explanation is about the data recording section of the sector, which is converted into the former.

Let me explain a little bit about some of them. Since a part of the pre-formatted header is recorded at almost the same clock rate as the T4 track group f4, the reproduction clock generator 10 must first read the address of the header part during reproduction.
First, 14 frequencies are selected and input by the controller as comparison frequencies to the P, L, and L circuits of the P, L, and L circuits. A clock signal is obtained, and the demodulator 11 outputs an address section data bit string using the reproduced clock signal and the binary signal from the comparator 9, and the address is confirmed by the controller section.

After that, as mentioned above, the controller 1 selects the data recording frequencies f1 to f4 corresponding to that address, and finally the recording data bit string is output from the de-sl unit 11, and the controller selects the recording data repeatedly. Data separation and RC, C (Error Corr
ecting Code), the original data is accurately demodulated.

FIG. 4 shows the control flow of the controller in this embodiment. First, it is determined whether there is an instruction to record or reproduce data from an external device (not shown) (step 1). In the case of data recording, a recording address and data are input from an external device (steps 2 and 3). Then, depending on the input address information, it is determined which of the groups Tl-T4 the recording frequency belongs to, and a 2-bit signal for selecting the recording frequency is sent to the multiplexer 2 (steps 4). Then, input the clock of the selected frequency (Step 5), and transmit the recorded data to the modulator 6 in synchronization with it (Step 6).
), the motor, etc. are controlled to record on the disk according to the modulated data (step 7). When playing data, please enter the playback address from the external device (Step 8)
, sends a 2-bit signal for selecting the recording frequency to the multiplexer 2 in the same way as during recording (step 9). Then, in step 10), the motor etc. are controlled to read data from the disk at the selected frequency.

Step 11): Input the demodulated playback data.
Separate the reproduced clock and reproduced data, add an error correction code (BCC), and reproduce the original data (
Step 12).

In the embodiment described above, the recording track group is divided into four groups of TI-JI14, but there may be more, for example, eight groups: T1 to TBS, and the recording frequency may also be finer, such as fl-fs. By doing so, the total recording capacity will increase, but on the other hand, the fx-fs reference frequency generator and part of the controller will become complicated, which will also cause a cost increase.
All you have to do is choose an appropriate tiger group based on cost and performance.

Further, in the first embodiment, a crystal controlled oscillator is used as the oscillator, but a VCO (voltage controlled oscillator) may be used and the frequency may be selected by changing the input power to the VCO in steps.

By providing track groups in the radial direction of the disk as described above, it becomes easy to change the clock rate while increasing the recording density.

〔effect〕

As described above, according to the present invention, the recording or reproducing speed is kept constant in an area consisting of a plurality of tracks in the radial direction,
By setting a different speed to the above-mentioned speed in an area different from the above-mentioned area, it becomes easier to control the recording or playback speed, and it also avoids the disadvantage that high-speed access is easily possible due to the inertia of the disk, as with C, L, and V. (C, A, V, which have a small storage capacity, C, L, V,
Since it can be constructed by combining the advantages of the /C, A, and V 1ifii systems, it is possible to achieve both high-speed access and large recording capacity.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the disc format according to the present invention, FIG. 2 is a block diagram showing the configuration of the recording system, and FIG.
The figure is a block diagram showing the configuration of the reproduction system, and FIG. 4 is a flowchart showing the control operation of the controller.

Claims (2)

[Claims] (1) In an information recording and reproducing apparatus that records and reproduces information on a disk-shaped recording medium, in the radial direction of the recording medium,
An information recording/reproducing apparatus characterized in that recording or reproducing is performed at a constant speed in an area consisting of a plurality of tracks, and recording or reproducing is performed at a speed different from the above-mentioned speed in an area different from the above-mentioned area. (2) The information recording and reproducing apparatus according to claim 1, wherein the recording medium rotates at a constant angular velocity.