JP3374921B2 - Disc recording method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc recording method suitable for recording information on an optical disc capable of optically recording and reproducing information .

[0002]

2. Description of the Related Art Discs include CLV type discs and CAV type discs. Since the CLV type disc has a constant linear velocity, more information can be recorded on one disc. However, since the rotational speed of the disk changes depending on the recording / reproducing position of the head, there is a problem that high-speed search becomes difficult.

On the other hand, the CAV type disk has a smaller rotational capacity than the CLV type disk because the rotational angular velocity of the disk is constant, but it has an advantage that high-speed retrieval is possible.

Therefore, in the CAV type disc,
In order to increase the capacity, for example, JP-A-58-1
Japanese Patent No. 75475 proposes a zone CAV method. In this zone CAV system, the disc is divided into a plurality of zones in the radial direction, and information is recorded and reproduced by clocks having different frequencies in each zone. By doing so, the capacity can be made larger than that of the CAV type disk while keeping the angular velocity of the disk constant.

[0005]

However, the above publication does not disclose a specific technique for more efficient zone division, and realizes a low-cost device for recording or reproducing information more efficiently. No specific configuration is disclosed.

The present invention has been made in view of the above circumstances, and is intended to enable more efficient data recording in a zone CAV disc.

[0007]

According to the disk recording method of the present invention, the number of sectors for recording one block of information in the innermost zone of the zones is m ₀ , and the minimum radius of the track of the disk is r ₀ . When the zone number is j, the innermost radius r _j of each zone having a zone number j of 1 or more is set according to the equation r _j ≧ r ₀ m ₀ / (m ₀ -j). .

The capacity M of the memory for storing the reproduction information from the disc is such that the number of recording sectors of one block of information in the innermost zone of the zones is m ₀ , and the innermost zone is 0.
The zone number that increments the outer peripheral side by 1 is j, the number of revolutions of the disk to stand by so that reading or writing of information from the memory does not overflow or underflow, R is the number of sector marks per track. When n ₀ , set to the minimum value among the values obtained according to the formula M (m ₀ -j)>Rn> j
You can

[0009]

In the disk recording method having the above construction, the radius r _j of the innermost circumference of each zone is set according to the equation r _j ≥r ₀ m ₀ / (m ₀ -j). Therefore, the zone can be set more efficiently and more data can be recorded.

In the disk recording method having the above structure, the memory capacity M is set to the minimum value among the values obtained according to the equation M (m ₀ -j)>Rn> j.
Therefore, it becomes possible to efficiently record data with a memory having a smaller capacity.

[0011]

1 is a block diagram showing the configuration of a first embodiment of a disk recording apparatus according to the present invention. Optical disc 1
Are rotated by the spindle motor 2 at a constant angular velocity. The optical head 3 is the optical disc 1
A laser beam is irradiated to and the data is recorded there.
In addition, the information recorded on the optical disc 1 is reproduced from the reflected light. The reproduction RF signal output from the optical head 3 is supplied to a signal processing circuit (not shown) via the amplifier 4 so that the recorded information can be read. The sector number decoder 5 reads the data corresponding to the sector mark on the optical disc 1 from the output of the amplifier 4 and outputs the sector number N to the zone number generator 6. The zone number generator 6 uses the sector number decoder 5
The zone number j corresponding to the supplied sector number N is generated and output to the data clock switching circuit 7. The data clock switching circuit 7 selects any one of the clocks P _{0 to} P ₄ corresponding to each zone of the optical disc 1 and supplies it to a circuit (not shown) as a recording / reproducing clock. Reference clock generation circuit 8
Generates a reference clock having a predetermined frequency and outputs it to the spindle servo circuit 9 and the sector number decoder 5.

FIG. 2 shows the format of the optical disc 1. In this embodiment, the optical disc 1 has ten sector marks formed in one track in the CAV format. Therefore, the sector mark is the optical disc 1
Are arranged on the same radial line (on a radial line) passing through the center of rotation of the above, from the innermost track to the outermost track. In this sector mark, sector numbers are sequentially incremented from number 0 to 1 from the innermost track to the outermost track. The optical disc 1 is divided into five zones in the radial direction.
The zone number j on the innermost side of each zone is 0, and the zone number j is incremented by 1 toward the outer periphery,
The outermost zone number j is 4. Although the tracks are formed in a concentric shape in FIG. 2, it is a matter of course that they may be formed in a spiral shape. The innermost radius of each zone is represented by r _j corresponding to each zone number.

Next, the operation will be described. The spindle servo circuit 9 controls the spindle motor 2 in synchronization with the reference clock supplied from the reference clock generation circuit 8 to rotate the optical disc 1 at a constant angular velocity. The optical head 3 reproduces the sector mark on the optical disc 1,
The reproduction RF signal is output. Sector number decoder 5
Separates the sector mark signal from the reproduction RF signal supplied from the optical head 3 via the amplifier 4, and reads the sector number N from this signal. Then, the read sector number N is output to the zone number generator 6.

[0014] Now, the track pitch q, 1 sector number marks per track n ₀ (the case of the embodiment of FIG. 2, n ₀
= 10), the innermost radius of the zone with the zone number j of 0 is r
_{When set to 0} , the radius r on the optical disc 1 where the optical head 3 is located can be expressed by the following equation. r = r ₀ + (N / n ₀ ) q (1)

In order to improve accessibility during reproduction, one unit (one block) of data of a recording signal is recorded in an integral number of sectors. The data for one block can be data for one frame in the case of a video signal, for example. Further, in order to increase the recording density, the number of occupied sectors per frame m _j in the zone of zone number j is set as shown by the following equation. m _j = m ₀ −j (2) Here, m ₀ is the number of occupied sectors of one frame in the innermost zone (zone with zone number j = 0). In the case of this embodiment, for example, 11 Is set to.

Further, in order to make the recording density in the innermost circumference of each zone substantially constant, the recording length on the optical disk 1 per frame is made the same. That is, the following conditional expression is satisfied. (2πr ₀ m ₀ ) / n ₀ = (2πr _j (m ₀ −j)) / n ₀ (3) When this equation is rearranged, the following equation is obtained. _{r j = (m 0 / (} m 0 -j)) r 0 ··· (4)

The zone number generator 6 includes a radius r at which the optical head 3 is located (obtained from the above equation (1)) and a radius r _j of the innermost circumference of each zone defined by the above equation (4).
And the zone number j of the zone in which the optical head 3 is located is determined from the comparison result. This zone number j is supplied to the data clock switching circuit 7.

Since the optical disc 1 rotates at a constant angular velocity, the frequency P of the recording data clock of the zone number j
_j is set according to the following equation so that it becomes higher in the outer zone. _{P j = (m 0 / (} m 0 -j)) P 0 ··· (5) where P ₀ is the clock frequency in the zone number j = 0.

The data clock switching circuit 7 is supplied with five types of clocks P _{0 to} P ₄ corresponding to the zone number j from a circuit (not shown), and the data clock switching circuit 7 is provided with the zone number generator 6. Zone number j supplied by
It is designed to select and output the corresponding clock. Data will be recorded or reproduced according to this clock.

FIG. 3 shows an example of specific values of the zone number j set as described above, its range (radius), the clock frequency P and the number of sectors m per frame. It can be seen that the clock frequency P of each zone becomes higher toward the outer zone. Further, the number of sectors m in which data of one block (one frame) is recorded is decreased by 1 toward the outer zone.

FIG. 4 shows a second embodiment of the disc recording apparatus of the present invention.
2 is a block diagram showing the configuration of the embodiment of FIG. 1, and the portions corresponding to those in FIG. 1 are designated by the same reference numerals. In this embodiment, the data to be recorded is stored in the memory (F
IFO) 21 and is stored. A reference clock for writing the input data is supplied to the memory 21 from a circuit (not shown).
The data modulator 22 modulates the data read from the memory 21 and outputs it to the LD driver 23. The LD driver 23 is adapted to control a semiconductor laser (not shown) built in the optical head 3 in response to the signal supplied from the data modulator 22.

The switch 25 selects a signal supplied from a system controller (not shown) or a jump pulse supplied from the window discriminating circuit 28 and supplies it to the tracking servo circuit 24.
The tracking servo circuit 24 controls an actuator (not shown) built in the optical head 3 in response to a signal from the switch 25 to execute tracking control. The switch 26 selects a signal supplied from the system controller or a write enable signal supplied from the window discrimination circuit 28 and outputs it to the LD driver 23. The switches 25 and 26 are adapted to be switched in response to a switching signal supplied from the system controller. The write enable signal output from the window discrimination circuit 28 turns on / off the switch 27. A clock having a predetermined frequency selected by the data clock switching circuit 7 is supplied as a read clock to the memory 21 via the switch 27.

The zone number generator 6 has a table as shown in FIG. 5, another zone number j corresponding to the sector number which is input from the sector number decoder 5, generates the frame header d _i. As shown in FIG. 5, the zone number j is defined corresponding to the radius r. In the zone of zone number 0, as in the case described above, one frame of data is recorded over 11 sectors. The number of sectors per frame is decremented by 1 in the outer zone and is set to 7 in the outermost zone. Further, in the case of this embodiment, data of 4940 frames is recorded in the zone of zone number 0. As shown in the figure, the header d ₁ of the first frame is the first sector. The header d _{494 0} of the 4940 frame is first 54,330 sectors. Similarly, in this embodiment, 6720, 9130, 13400 or 22 are assigned to each zone of zone numbers 1 to 4.
Each of the 500 frames is recorded.

The window discrimination circuit 28 discriminates the time T ₀ from the head data of the frame to be recorded to the header of the frame to be recorded with reference to the reference clock of the input data, and the time T ₀ and (j / M ₀ ) Tf. Then, the processing is performed according to the following conditions. T ₀ > (j / m ₀ ) Tf: recording start T ₀ ≦ (j / m ₀ ) Tf: R times, waiting for rotation Here, Tf represents the time of one frame of input data. Further, the rotation speed R is set to a value that satisfies the following equation. M (m ₀ −j)> Rn ₀ > j (6) Here, M represents the capacity (length) of the memory 21.

The smaller the number of rotations R, the shorter the waiting time. Therefore, R is set to 1, for example. Further, n ₀ is 10 in this embodiment. As a result, Rn ₀
Is 10. In this embodiment, j has a maximum value of 4
Therefore, the condition of Rn ₀ > j (10> 4) is satisfied.

Since m ₀ is 11, the minimum value of m ₀ -j is 7 (= 11-4). Therefore, if M is set to the value 2, M (m ₀ −j) becomes 14 (= 2 × 7), which is larger than 10. It is possible to set a larger value as the value of M, but the cost becomes higher accordingly. Therefore, in the case of this embodiment, if the capacity M of the memory 21 is set to store data for two frames,
It is possible to continuously record (or reproduce) without causing overflow or underflow.

Next, the recording operation of the embodiment of FIG. 4 will be described with reference to the flow charts of FIGS. In the recording mode, the write operation to the memory 21 is processed according to the flowchart of FIG. That is, the memory loading operation is started in step S1, and two frames of data are loaded in step S2. Further, in step S3, the memory write address is reset. By the above-described processing of steps S1 to S3, when two frames of data are written, the process returns to step S1 and the subsequent processing is repeatedly executed. That is, the input data is sequentially written into the memory 21 for two frames.

Next, the overall recording operation will be described with reference to the flowchart of FIG. 7. First, in step S11, a frame header (d _i ) for starting recording is designated. Then, in step S12, the header is searched, and when the header is searched, the still operation is performed on the track. Further step S
At 14, recording is put on standby.

Next, in step S15, the phase difference (time difference) T ₀ between the start portion of the frame of the input signal and the target header to be recorded is measured. In step S16, it is determined whether or not the write address to the memory 21 exceeds the read address. That is, it is determined whether the following conditional expression is satisfied. T ₀ > (j / m ₀ ) Tf (7)

When this conditional expression is satisfied, the memory write address does not overtake the read address, so the flow proceeds to step S18, where one frame of data is read from the memory 21, and in step S19, 1 is written on the optical disc 1. The data for the frame is recorded. That is, when the window determination circuit 28 determines that the memory write address does not overtake the read address, the window determination circuit 28 generates a write enable signal and turns on the switch 27. As a result, the clock of the predetermined frequency selected in the data clock switching circuit 7 as described above is switched to the switch 2
It is supplied to the memory 21 via 7 as a read clock. As a result, one frame of data read from the memory 21 is modulated by the data modulator 22, and the LD
It is supplied to the driver 23. Switch 2 in recording mode
Since 6 has been switched to the lower side in the drawing, the recording permission signal output from the window discrimination circuit 28 is supplied to the LD driver 23. Therefore, the LD driver 23 controls the optical head 3 in response to the signal supplied from the data modulator 22 to record one frame of data on the optical disc 1.

If it is determined in step S16 that the memory write address exceeds the read address, that is, if T ₀ is equal to or greater than (j / m ₀ ) Tf, the process proceeds to step S17. Then, the recording operation is awaited until the optical disk 1 rotates R times. That is, at this time, the window discrimination circuit 28 generates a jump pulse. In the recording mode, since the switch 25 is also switched to the lower side in FIG. 4, this jump pulse is supplied to the tracking servo circuit 24. The tracking servo circuit 24 controls the optical head 3 when the jump pulse is supplied, and causes the light beam to jump back to the inner circumference of one track. After that, at the timing when the target header arrives, steps S18 and S19 are performed.
Processing is executed and data for one frame is recorded.

After the processing of step S19, step S2
In step 0, it is determined whether or not the data for the next one frame is to be recorded on the disc. If it is determined that the data is to be recorded, the process returns to step S15 and the subsequent processing is repeated. If it is determined in step S20 that it is not necessary to record, the process proceeds to step S21 and the recording operation is ended.

Since the capacity M of the memory 21 is usually an integer, it is set to 2 in the above embodiment, but if it is not necessary to be an integer, in the above embodiment, the formula (6) is used. Accordingly, the value will be set to a value larger than 10/7.

FIG. 8 shows the timing in the recording operation. This timing chart shows a case where data is recorded in the zone whose zone number j is 3. In this zone, 1 frame of data is recorded over 8 sectors (FIG. 5). In the case of this embodiment, the reference value T in the window discrimination circuit 28
w (= (j / m ₀ ) Tf) is j = 3, m _{0 =} 11, Tf
Is 11 in terms of the number of sectors, which is 3. Therefore, when T ₀ is larger than 3 sectors, that is, when there are 4 sectors or more, recording is performed as it is. On the other hand, when T ₀ is 3 sectors or less, one jump is performed. In the embodiment shown in FIG. 8, the time T ₀₁ between the beginning of the first frame F1 and the frame header d _{1 of the} sector in which the frame F1 is recorded is 5, so that the data already written from the memory 21 is 1 Data for a frame is read out and recorded in an area of 8 sectors starting from the frame header d ₁ .

In the subsequent frame F2, the time T ₀₂ between the head portion of the frame F2 and the frame header d ₂ which is the recording target.
Since there are two sectors, the read address will overtake the write address if the read operation is continued. Therefore, in this case, a jump is made to the inner circumference side of one track. This jump timing may be any timing as long as it can jump to the inner circumference of one track and return to the target frame header.

In the case of this embodiment, the recording of the frames F3 and F4 is executed as it is because the corresponding time T ₀₃ is 9 and T ₀₄ is 6. However frame F5
Since the time T ₀₅ is 3, recording is performed after one track jump.

As described above, the timing of reading from the memory 21 is adjusted by repeating jumps as necessary, but writing to the memory 21 is performed by F.
1, F2, F3, F4, F5, F6 are sequentially and continuously performed.

FIG. 9 shows the timing during reproduction. In this case, the data reproduced from the optical disc 1 is written in the memory 21. In the case of this embodiment, T
_{Since 02} and T ₀₃ are 9 and 6, respectively, frames f2 and f3 are continuously read from the optical disc 1 and the memory 2
Written to 1. Since T ₀₄ is 3, one track jump is performed. Then, thereafter, from the timing when the frame header d ₄ arrives, the data after the frame f 4 is reproduced and written in the memory 21. Memory 21
Readout from frames F1, F2, F3, ...
Is continuously performed.

[0039]

As described above, according to the disk recording method of the present invention, the radius r _j of the innermost circumference of each zone having a zone number j of 1 or more is r _j ≧ r ₀ m ₀ / (m ₀ -j) Since the setting is made in accordance with the equation, it is possible to efficiently perform zone division and record a large amount of data on the disc.

According to the disc recording method of the present invention,
Since the memory capacity M is set to the minimum value among the values obtained according to the equation M (m ₀ -j)> Rn ₀ > j, not only can information be continuously recorded and reproduced. Therefore, the capacity of the memory used for that purpose can be reduced, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a disk recording device of the present invention.

FIG. 2 is a diagram illustrating a recording format of an optical disc 1 in the embodiment of FIG.

FIG. 3 is a diagram illustrating division of each zone of the optical disc 1 in the embodiment of FIG.

FIG. 4 is a block diagram showing the configuration of a second embodiment of the disc recording apparatus of the present invention.

5 is a diagram for explaining the contents of a table included in the zone number generator 6 in the embodiment of FIG.

FIG. 6 is a flowchart illustrating a write operation of memory 21 in the embodiment of FIG.

FIG. 7 is a flowchart illustrating an operation at the time of recording in the embodiment of FIG.

FIG. 8 is a timing chart for explaining an operation at the time of recording in the embodiment of FIG.

FIG. 9 is a timing chart for explaining the operation during reproduction in the embodiment of FIG.

[Explanation of symbols]

1 optical disc 2 spindle motor 3 Optical head 5 sector number decoder 6 Zone number generator 7 Data clock switching circuit 21 memory 28 Window discrimination circuit

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G11B ^7/ 00-7/013 G11B 7/28-7/30 G11B 20/10-20/16 351

Claims (2)

(57) [Claims] 1. A sector mark for dividing one track into a plurality of sectors is formed in a CAV format on the same radial line from the innermost track to the outermost track, and is divided into a plurality of zones in the radial direction. In the disc recording method for recording information on a disc, one block of information is recorded over m ₀ sectors in the innermost zone of the zones, and the number of recording sectors of one block of information in the outermost zone is set. The disk radius is gradually decreased by 1, the minimum radius of the track of the disc is r ₀ , the number j of each zone is 0 in the innermost circumference, and the zone number on the outermost side is 1
When incrementing by one, zone number j
Is set to 1 or more, the radius r _j of the innermost circumference of each zone is set according to the equation r _j ≧ r ₀ m ₀ / (m ₀ -j). 2. Playback information from the disc is stored.
The memory capacity M is set to one block in the innermost zone of the zones.
The number of information recording sectors is m ₀ , the innermost circumference is 0, and the outer circumference is incremented by 1.
Zone number to read j, reading or writing of information from the memory is over
To wait so that it does not flow or underflow
Let R be the number of rotations of the disk, and n ₀ be the number of sector marks per track.
When, set to the minimum value among the values obtained according to the formula of M (m ₀ -j)> Rn ₀ > j
The disk recording method according to claim 1, wherein