JP3024542B2 - Optical disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly to an optical disk device for reading and writing data at a fixed recording wavelength.

[0002]

2. Description of the Related Art The recording area of an optical disk is divided into a plurality of concentric tracks whose radius gradually increases. Since the length of one track increases as it approaches the outer circumference of the optical disk, if the amount of data to be recorded on each track is the same, the recording density decreases as it approaches the outer circumference, and the recording area can be used effectively. Can not. Therefore, there is an optical disk device that keeps the recording wavelength constant and increases the amount of data recorded on one track as the radius increases.

There are two types of such optical disk devices, one of which is the rotational speed (angular speed) of the optical disk.
Is kept constant, and the frequency of the recording clock is increased as approaching the outer periphery. The other is to keep the frequency of the recording clock constant and to decrease the rotational speed of the optical disk as the position of the track to be read / written approaches the outer circumference so as to have a constant recording wavelength.

FIG. 7 shows a configuration of a recording system of an optical disk apparatus which is conventionally used and rotates an optical disk at a constant angular velocity and records data at a constant recording wavelength. The optical disc device 101 includes a recording data processing unit 103 that converts input data 102 to be recorded into a unit amount of data sequence called a sync block, and a recording data memory 104 that temporarily stores a sync block to be written on the optical disc. I have.

A memory writing control unit 105 for writing data output from the recording data processing unit 103 to the recording data memory 104 and a memory reading control unit 10 for controlling reading of data stored in the recording data memory 104
6. Further, an optical head 107 for writing the read data to the optical disk, a head driving unit 108 for driving the optical head 107, and a data amount calculation track control for calculating whether or not writing to the next track should be interrupted The unit 109 is provided.

A sync block (hereinafter, referred to as SB)
Is a 188-byte data string including a 2-byte synchronization signal, a 2-byte ID indicating an address, 168-byte data, and a 16-byte error correction code.

[0007] The recording area of the optical disk is composed of n + 1 concentric track areas from the innermost track 0 to the outermost track n (n is an integer of 1 or more). Assuming that the recording data amount to be recorded in the track area of the 0th number is “A”, only “A” data is written in the recording data memory 104 in a fixed input cycle. The input cycle is the same as the field cycle, and the track synchronization is the same as the input fixed cycle field synchronization. Therefore, the track synchronization rotates at a constant angular velocity according to the field synchronization. As a result, data of only “A” is written to the recording data memory 104 during one track rotation.

In order to keep the recording wavelength constant, the speed of the recording clock increases as the track approaches the outer periphery, and the reading speed from the recording data memory 104 increases. As a result, the recording data amount by ΔA increases each time the track number increases by “1”. The m-th (m is n> = m> =
The data amount recorded on the (track number indicated by 0) track is “A + ΔA × m”. Recording data memory 1
Since the amount of data to be written to the optical disk 04 is “A” during the input cycle of one rotation of the optical disk, when data is recorded on the m-th track of the optical disk, the amount of data in the recording data memory 104 is recorded during the period of recording one track. Is “ΔA
× m ”.

Therefore, when recording on tracks other than the zeroth track is continued, the amount of data in the recording data memory 104 gradually decreases, and an underflow occurs. In order to prevent this, the data amount calculation track control unit 109
Are the data amount “A” written to the recording data memory 104 and the data amount “A + ΔA ×
m ". Then, every time the integrated value reaches the data amount" A ", the reading from the recording data memory 104 and the recording operation on the optical disk are interrupted for one track period. ing.

For example, assuming that the data amount in one field is 380 SB, memory write control unit 105
As a result, 380 SB data is stored in the recording data memory 104 for each field. It is also assumed that only 380 SB of data is recorded in the 0th track area on the innermost circumference, and the recording data amount increases by 4 SB each time the track number increases by “1”. In the 0th track area, the amount of data input to the recording data memory 104 and the amount of data recorded on the optical disk are equal, so that the integrated value of the difference remains “0” and the constant repetition without interruption. Recording on the optical disk is performed periodically.

However, when recording in the first track area, only 384 SB of data is read from the recording data memory 104 during one track period, and the storage amount is reduced by 4 SB. If the operation is continued as it is, the recording data memory 104 becomes empty and an underflow occurs. Therefore, when the integrated value of the difference reaches 380 SB, that is, when recording is performed in the first track area, the recording data memory 1 is stored only once every recording for 95 tracks.
Reading from 04 has been suspended. Similarly, when recording in a track area of another number, the integrated value of the difference is 380S
The recording is interrupted for one track each time B is reached. Insufficient data for 380 SB is replenished while recording is interrupted, so that underflow is prevented.

FIG. 8 shows a configuration of a reproducing system of an optical disk apparatus which rotates a optical disk at a constant angular velocity and records data at a constant recording wavelength. The optical disk device 121 includes an optical head 122 for reading data from the optical disk, a head driving unit 123 for driving the optical head 122, a reproduction data memory 124 for temporarily storing the read data, and a read data memory 124 for storing the read data. A memory write control unit 125 for writing to the reproduction data memory 124 is provided.

The memory read control unit 126 is a circuit for reading data from the reproduction data memory 124 in a fixed output cycle. The reproduction data processing unit 127 extracts a data portion from the sync blocks read from the reproduction data memory 124, corrects data errors based on the error correction code, and outputs reproduction data 128. The data amount calculation track control unit 129 includes the reproduction data memory 124
This is a circuit for determining whether or not the reading of the next track should be interrupted based on the integrated value of the difference between the data amount read from and the data amount to be written.

As in the case of the recording system, the recording area of the optical disk extends from the innermost track 0 to the outermost track n (where n is 1).
It is composed of n + 1 track areas up to the above (integer) tracks. The recording data amount recorded in the 0th track area is “A”, and the recording data amount increases by ΔA as approaching the outer periphery. The m-th (m is n>
= M> = 0 track number) The data amount read from the track is “A + ΔA × m”. Also,
Data of only "A" is read from the reproduction data memory 124 in a fixed output cycle, and the output cycle matches the track rotation cycle.

When data is read from the m-th track and written to the reproduction data memory 124, the data amount in the reproduction data memory 124 during reading of one track is "ΔA ×
m ". Therefore, if the reproduction from the track other than the 0th track is continued, the reproduction data memory 1 gradually increases.
The amount of data in 24 increases and overflow occurs.

To prevent this, the data amount calculation track control unit 129 calculates the data amount “A” read from the reproduction data memory 124 and the data amount “A + ΔA” read from the optical disk and written into the reproduction data memory 124.
× m ”is sequentially accumulated, and every time it reaches the data amount“ A ”, the operation of reading from the optical disk and writing to the reproduction data memory 124 is interrupted for one track period. I have.

For example, the data amount in one field is 380 SB, and the innermost 0th track area is 38
It is assumed that a recording data amount of 0SB is provided, and each time the track number increases by "1", it increases by 4SB. 380 SB for each field from the reproduction data memory 124
Is read out. In the 0th track area, since the amount of data read from the reproduction data memory 124 is equal to the amount of data read from the optical disk and written to the reproduction data memory 124, the integrated value of the difference is “0” and the operation is interrupted. The reading from the optical disc is performed at a constant repetition cycle without any change.

However, when reproducing the first track area, the reproduction data memory 124 stores three tracks in one track period.
Data of only 84 SB is written, and the storage amount increases by 4 SB. If the reproduction operation is continued as it is, the reproduction data memory 124 overflows. Therefore, when the integrated value of the difference reaches 380 SB, that is,
When reproducing the first track area, the read operation from the optical disk and the write operation to the reproduction data memory 124 are interrupted only once every time reproduction of 95 tracks is performed. Since the excess 380 SB of data is read while the reproduction is suspended, overflow is prevented.

[0019]

In the optical disk apparatus described above, when the integrated value of the difference between the input and the output reaches the data amount "A" for one cycle, the access to the optical disk is suspended for one rotation. This prevents underflow or overflow. At this time, the condition is that the rotation cycle of the track and the input cycle or the output cycle are the same cycle. Under such conditions, the interruption of the access to the optical disk can be controlled by the operation of accumulating the difference. However, if the period is different, should the access to the optical disk be interrupted based on the operation result? It cannot be determined whether or not.

For example, if the amount of data written to the recording data memory is 380 SB per input cycle and the amount of data recorded in the first track area is 384 SB, the accumulated value of the difference becomes 380 SB during 95 rotations. . However, when the input cycle is longer than the rotation cycle of the optical disk and only 94 input cycles are performed during 95 rotations, the actual input / output difference is 760 SB. Therefore, even if the recording on the optical disk is interrupted when the integrated value of the difference reaches 380 SB, the amount of data stored in the recording data memory gradually decreases, and an underflow occurs.

In addition, in order to calculate the integrated value and to compare the value with the reference data amount, it is necessary to use circuit elements such as adders and comparators. And it is not suitable for high-speed operation.

It is therefore an object of the present invention to provide a simple optical disk apparatus having a circuit configuration capable of controlling access to an optical disk so that overflow or underflow of a buffer memory does not occur.

[0023]

According to the present invention, there is provided a recording data memory having a plurality of storage areas of a predetermined size for temporarily storing data to be recorded on an optical disk;
Writing means for sequentially writing data to the recording data memory at a constant speed, and when starting to record data on any one track of the optical disk, all or a part of the data contains data that has not been read yet. Determining means for determining whether or not the written storage area is equal to or more than a required number obtained by dividing a data amount that can be written to one track by a predetermined size and adding 1 to a value obtained by rounding up the decimal point or less; Disk writing means for reading data from a recording data memory and writing it to an optical disk when the determination means determines that there is a required number or more of written storage areas with unread data in all or part thereof. And a written storage area having data that has not yet been read in all or in part by the determination means is required. A disc writing suspending means for suspending the reading of data from the recording data memory and the writing of data to the optical disc until it reaches the next writing start time when it is determined that there is not more than one disc; The equipment is equipped.

That is, according to the first aspect of the present invention, when writing to the next track is started, it is determined whether or not the recording data memory has more data than the data amount to be recorded on one track of the optical disk. It is determined as a unit. When the number of blocks in which data is stored is equal to or more than the required number, writing to the track is performed, and when the number is smaller than the required number, the writing is interrupted. When there is no more than the required number of blocks, the recording is interrupted, and no underflow occurs during the recording of one track. In addition, since the block is used as a unit, the determination can be easily performed.

According to the second aspect of the present invention, a reproduction data memory having a plurality of storage areas of a predetermined size for temporarily storing data read from an optical disk, and sequentially reading data from the reproduction data memory at a constant speed. A reading unit, wherein when the reading of data from any one track of the optical disk is started, an empty storage area is set to 1
A discriminating means for dividing the amount of data read from one track by a predetermined size and discriminating whether or not there is a required number of values obtained by adding 1 to a value obtained by rounding up the decimal point, and an empty storage area by the discriminating means When it is determined that there is more than the number of data, when the disc reading means reads data from one track of the optical disc and stores it in the reproduction data memory, and when the discriminating means determines that the required number of empty storage areas does not exist more than the required number The optical disk apparatus is provided with a disk read interruption means for interrupting the reading of data from the optical disk and the writing of data to the reproduction data memory until the next reading start time comes after the optical disk makes one round.

That is, according to the second aspect of the present invention, when reading is started from the next track, it is determined on a block-by-block basis whether or not an empty area larger than the data amount read from one track of the optical disc exists in the reproduction data memory. Is determined. When the number of empty blocks is equal to or more than the required number, reading from this track is performed,
Reading is interrupted when the required number is not exceeded. When there is no free block larger than the required number, reading from the optical disk to the reproduction memory is interrupted, so that the reproduction data memory does not overflow during reading of one track. In addition, since the block is used as a unit, the determination can be easily performed.

According to the third aspect of the present invention, there is provided a recording data memory for temporarily storing data to be recorded on an optical disk;
Writing means for sequentially writing data to the recording data memory at a constant speed; and when recording of data on any one track of the optical disk is started, data of an amount equal to or more than the data to be recorded on that track is recorded on the recording data memory. Discriminating means for discriminating whether or not the data exists in the recording data memory; and disc writing means for reading the data from the recording data memory and writing the data to the optical disc when the discriminating means determines that the data has a data amount or more. And the format
When it is determined by another means that there is no data larger than the data amount in the recording data memory, the optical disk makes one rotation and reads data from the recording data memory and writes data to the optical disk until the next writing start time comes. And a disk write suspending means for suspending the operation.

That is, according to the third aspect of the invention, when writing to the next track is started, it is determined whether or not data larger than the data amount to be recorded on the track is prepared in the recording data memory. When data exceeding the required amount exists in the recording data memory, writing to the track is performed, and when not exceeding the required amount, the writing is interrupted. When there is no more data than the required amount, the recording is interrupted, so that no underflow occurs during the recording of one track. In addition, although it is complicated to determine whether or not to interrupt the processing for each block, since the data amount itself is used, accurate determination can be performed.

According to the fourth aspect of the present invention, there is provided a reproduction data memory for temporarily storing data read from the optical disk, reading means for sequentially reading data from the reproduction data memory at a constant speed, 1
Discriminating means for judging whether or not an empty area larger than the data amount read from the track when data reading is started from one track is present in the reproduced data memory; Then, when it is determined that the data is read from the track of the optical disc and stored in the reproduction data memory, and when the discrimination means determines that there is no free area larger than the data amount in the reproduction data memory, the optical disc is set to 1 The optical disk apparatus is provided with a disk read interruption means for interrupting the reading of data from the optical disk and the writing of data to the reproduction data memory until the next read start time comes.

That is, according to the fourth aspect of the present invention, when reading is started from the next track, it is determined whether or not an empty area larger than the data amount read from one track of the optical disc exists in the reproduction data memory. I have.

According to the fifth aspect of the present invention, the data amount used as a criterion for determining whether or not the recording should be interrupted is the maximum value of the data amount that can be recorded on one track of the optical disk.

That is, according to the fifth aspect of the present invention, the recording is interrupted when there is no more than the maximum amount of data that can be recorded on one track in the recording data memory. When there is no free area in the reproduction data memory equal to or larger than the maximum amount read from one track, reading from the optical disk is interrupted. As described above, since the discrimination is performed based on the maximum value that can be recorded on one track, it is not necessary to identify the recording data amount for each track, and the discrimination can be easily performed.

According to the sixth aspect of the present invention, the optical disk is rotated at a constant angular velocity, and the clock frequency, which is a reference for the data reading / writing speed, increases according to the radius of the track. It is recorded.

According to the seventh aspect of the present invention, the optical disk reads and writes data in accordance with a clock having a constant frequency, and changes the rotation speed so that the linear velocity becomes constant. Is to be recorded.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION

[0036]

FIG. 1 shows an outline of the configuration of a recording system of an optical disk device according to an embodiment of the present invention. This optical disk device rotates an optical disk at a constant angular velocity and increases the speed of a recording clock as a track approaches an outer periphery. Thereby, recording is performed at a fixed recording wavelength. Therefore, the closer to the outer circumference, the larger the amount of recording data recorded on one track. Also, the recording area of the optical disk is from the 0th track at the innermost circumference to the nth track at the outermost circumference (where
It is composed of n + 1 concentric track areas up to the (integer) track.

The optical disk device 11 includes a recording data processing unit 13 for converting input data 12 to be recorded into a data sequence of sync blocks, a recording data memory 14 for temporarily storing sync blocks to be written on the optical disk, A memory writing control unit 15 for writing data output from the processing unit 13 to the recording data memory 14 is provided.
In addition, a memory read control unit 16 that controls reading of data from the recording data memory 14, an optical head 17 that writes data to an optical disk, a head driving unit 18, and an operation that determines whether or not to interrupt writing to a track. A memory amount calculation track control unit 19 is provided.

The writing to the recording data memory 14 is repeatedly performed at a constant cycle, and the writing of the data amount "A" is performed at every writing cycle (field cycle). The storage area of the recording data memory 14 has a data amount “A”.
Are divided into a plurality of blocks in units of. These plural blocks are repeatedly read and written cyclically, and the recording data memory 14 is used as a ring buffer.

The memory write control unit 15 outputs a write completion signal 21 indicating that data writing has been completed for each block. Also, the memory read control unit 16
Outputs a read completion signal 22 indicating that data reading has been completed for each block.

The memory amount calculation track control unit 19 is in a write completed state in which all or a part of the data has not yet been read after the writing is completed, or the writing is completed after all the data in the block has been read. It is managed for each block whether or not it is in the state until it is done.

The memory amount calculation track control unit 19 includes a flip-flop circuit (not shown) for each block, and sets the flip-flop circuit when the write completion signal 21 of the corresponding block is input, and completes reading. When the signal 22 is input, the flip-flop circuit corresponding to the block is reset. The output signals of these flip-flop circuits will be referred to as block state display signals.

When starting writing to the next track, the memory amount calculation track control unit 19 starts the flip-flop circuit for the required number of consecutive blocks or more starting from the first block of data to be written to this track. Is set or not. If the required number of blocks or more have been written, the data is read from the recording data memory 14 and recorded on the corresponding track.

On the other hand, when the number of blocks in the write completed state is not equal to or greater than the required number, the recording data memory 14 is used until the optical disk makes one rotation and the next write timing arrives.
The recording of data from an optical disk is interrupted.

It is assumed that the amount of data that can be recorded in the 0th track area on the innermost circumference of the optical disk is "A", and that the amount of data that can be recorded on that track increases by ΔA each time the track number increases by "1". At this time, the recording data amount “B” of the m-th track area is represented by “A + ΔA × m”. However, here, the outermost data amount is 2A.
Shall be smaller than

Data of 2A, which is the maximum amount of data recorded on one track, may be stored in three blocks in a distributed manner. Therefore, if there are three consecutive blocks in a write-completed state in which data read-out has not been completed after the write-in completion, data will not underflow during the writing of the next track. Therefore, the memory amount calculation track control unit 19 controls whether or not to interrupt the recording on the track based on whether or not the block status display signals of three or more consecutive blocks indicate the write completion state. ing.

The writing cycle (field cycle) to the recording data memory 14 and the reading cycle (track cycle) corresponding to one rotation of the optical disk do not coincide with each other, and each cycle is arbitrary. However, the read cycle needs to be shorter than the write cycle. The amount of data read from the recording data memory 14 during one read cycle is the smallest when the data is recorded in the innermost 0th track area.
Since it is assumed that this data amount “A” is equal to the data amount “A” written to the recording data memory 14 during one writing cycle, the recording data memory 14 is stored in the recording data memory 14 even after infinite time has elapsed. To avoid overflow, the read cycle and the write cycle must be equal or the read cycle must be shorter. Therefore, here, the read cycle is set shorter than the write cycle.

Next, the operation of the recording system of such an optical disk device will be described.

It is assumed that the amount of data written to the recording data memory 14 in one writing cycle is 380 SB. The recording data memory 14 is managed by being divided into a plurality of blocks in units of 380 SB. Here, the recording data memory 14 includes first to fifth blocks.
The recording data processing unit 13 converts the input data 12 into a data string in sync block units,
Means that the converted sync block is 380S every writing cycle.
The data is sequentially written to the recording data memory 14 for each B.

The data write destination moves to the next block every write cycle, and five blocks are used cyclically. The memory write control unit 15 sets the corresponding flip-flop circuit of the memory amount calculation track control unit 19 every time the writing of one block is completed.

When the timing to start writing to the next track arrives, the memory amount calculation track control unit 19 determines whether the three consecutive blocks from the block in which the first data is stored are in the writing completed state. A check is made based on the block status display signal. When three blocks indicate the write completion state in succession, a read instruction of data to be recorded on the next track is output to the memory read control unit 16. As a result, data is sequentially read from the recording data memory 14 and recording is performed on the corresponding track via the optical head 17.

When reading of all data in one block is completed, the memory read control unit 16 outputs a read completion signal 22 for that block. In response, the corresponding flip-flop circuit in the memory amount calculation track control unit 19 is reset.

On the other hand, when writing to a track is started, if three consecutive blocks are not in a writing completed state, data may underflow during the writing operation to this track. Therefore, the memory amount calculation track control unit 19 does not output a read instruction until the next write timing comes until the optical disk makes one rotation, and interrupts the recording operation on the optical disk. The optical head 17 is not moved.

FIG. 2 shows an example in which data recorded on one track exists over two blocks. Here, the data amount written to the recording data memory 14 in one writing cycle is 380 SB.
3 shows a case where the data amount read from the recording data memory 14 in one read cycle is 400 SB. The recording data amount of one track increases every ten tracks.

The 400 SB data 21 to be recorded on the first track starts from the head of the first block 22. Therefore, 400 SB data to the first track includes 380 SB of the first block 22 and the second block 2
3 are stored over the first 20SB.
360S of the data 24 recorded on the second track
B is stored in the second block 23, and the remaining 40SB is stored in the third block 25. Similarly, 340SB of the data 26 recorded on the third track is the third data.
The remaining 60 SBs are stored in the fourth block 27 in the block 25.

As described above, in addition to the case where the recording data amount of the track is stored over two blocks, there is also a case where the amount of data recorded extends over three blocks. For example, the first block stores 12 SBs, the second block stores 380 SBs, and the third block stores the remaining 8 SBs.

FIG. 3 shows an example in which data to be recorded on one track is present over three blocks. Here, the recording data amount of one track is 600 SB. Of the 600 SB data 31 recorded on the second track, 160 SB is in the second block 32 and the next 380 SB is in the third block 33.
The remaining 60 SB are stored in the fourth block 34 separately. The maximum recording data amount of one track is 76
Since it is 0SB, it does not extend over four or more blocks. Therefore, if three consecutive blocks are in the write completed state, it is possible to guarantee that no data underflow will occur during the writing of the next track.

FIG. 4 shows an example of each signal waveform in the recording system of the optical disk device shown in FIG.
Data to be written to the recording data memory 14 (a in the figure)
Is 3 cyclically in the first to fifth blocks with a constant write cycle.
The data is written in units of 80 SB. In the figure, the data amount of 380 SB is represented as “A”. The number added after the letter "A" indicates a block number.

The data read from the recording data memory 14 (FIG. 4B) is 400 SB per one read cycle (track cycle). In the figure, 40 to be read
The data amount of 0SB is represented as “B”. The number given in each read cycle indicates a track number. In the read cycle, a period indicated by a broken line x indicates a period in which recording on the track is interrupted.

While the write enable signals (c to g in FIG. 4) for the first to fifth blocks of the recording data memory 14 are at a low level, writing to the corresponding blocks is performed. During the period when the read enable signals (h to l in the drawing) to the first to fifth blocks of the recording data memory 14 are at the low level, data is read from the corresponding blocks. The block status display signals (m to q in the figure) indicating whether the first to fifth blocks are in the write completed state change to high level when the write is completed, and read all data in the block. Changes to a low level when is completed.

At time T ₁₁ , the write enable signal (FIG. 9C) goes low, and writing of data to the first block 41 starts. At time T ₁₂ that ended in writing to the first block 41, the block status signals of the first block (FIG. M) is changed to a high level. Similarly, each time the writing of the second and third blocks 42 and 43 is completed, the corresponding block status display signal (n and o in FIG. 3) goes high.

[0061] At time T _13, the first to become both high-level block status signals corresponding to the third block, the memory amount calculation track control unit 19 that data into three consecutive blocks were prepared recognize. Therefore, writing from time T ₁₃ to the optical disk is started. Time T
From ₁₃ to time T ₁₄ 380s from the first block 41
B data is read, data of 20SB is read to time T ₁₄ ~ time T ₁₅ from the second block 42. Data read from the first and second blocks 41 and 42 are recorded in a first track area 51 of the optical disc.

[0062] 1 period for writing a block of data to the recorded data memory 14, for example as compared to the length of time T ₁₁ ~ time T _12, the period for reading a block of data from the recorded data memory 14 (time T ₁₃ ~ the length of the time T ₁₄₎ is shorter. This is because, in addition to the track cycle being shorter than the write cycle, the recording on the optical disk is performed at a constant recording wavelength, so that the clock speed increases according to the amount of data recorded on the track.

[0063] Since the reading of all the data of the first block 41 is completed at time T _14, the corresponding block status signal (FIG. M) is reset to a low level. A part (20 SB) of the second block has already been read, but the reading of the remaining 360 SB has not been completed, so that the second block remains at the high level when the recording to the first track area is completed. .

[0064] At time T ₁₅ the recording is completed in the first track area, the optical head 17 is moved to the second track. At this point, the writing of the fourth block 44 has not been completed yet, and only the block state display signals corresponding to the two blocks of the second and third blocks 42 and 43 are at the high level, and are less than three blocks. Therefore, memory amount calculation track control unit 19, in the next track cycle from time T ₁₅ to time T _16, interrupting the writing to the reading and an optical disk data from the recorded data memory 14. The optical head 17 is held at the position of the second track.

[0065] In the meantime, since the writing of the fourth block 44 is completed, at time T ₁₆ after the optical disc is round, three consecutive blocks again is in the write completion state. Therefore, the memory amount calculation track control unit 19
It starts recording from time T ₁₆ to the second track region 52. 360 SB read from the second block and 40 SB read from the third block are recorded in the second track area 52. By repeating such an operation, recording on the optical disk is sequentially performed.

Next, the reproduction system of the optical disk device will be described.

FIG. 5 shows the outline of the configuration of the reproducing system of the optical disk device. This optical disk device rotates the optical disk at a constant angular velocity similarly to the recording system, and increases the speed of the reproduction clock as the track approaches the outer circumference.

The optical disk device 61 includes an optical head 62 for reading data from an optical disk, a head driving unit 63 for driving the optical head 62, a reproduction data memory 64 for temporarily storing the read data, and a read / write data memory 64. Memory writing control unit 65 for writing the read data to reproduction data memory 64
It has.

The memory read control section 66 is a circuit for reading data from the reproduction data memory 64 in a fixed output cycle. The reproduction data processing unit 67 includes the reproduction data memory 6
The data part is extracted from the sync blocks read out from the decoder 7, the data error is corrected based on the error correction code, and the reproduced data 68 is output. The memory amount calculation track control unit 69 is a circuit that performs a calculation as to whether or not reading from a track is interrupted.

The reading from the reproduction data memory 64 is repeatedly performed at a constant cycle, and only the data amount “A” is read from the reproduction data memory 64 every reading cycle (field cycle). The storage area of the reproduction data memory 64 is divided into five blocks in units of data amount "A", and is repeatedly read and written cyclically.
The memory write control unit 65 outputs a write completion signal 71 indicating that data writing has been completed for each block. Further, the memory read control unit 66 outputs a read completion signal 72 indicating that data reading has been completed for each block.

The memory amount calculation track control section 69 manages the empty state of each block. The memory amount calculation track control unit 69 includes a flip-flop circuit (not shown) for each block, sets the flip-flop circuit when a write completion signal 71 of the corresponding block is input, and sets a read completion signal 72 When input, the flip-flop circuit corresponding to the block is reset.

When reading from the next track is started, the memory amount calculation track control section 69 resets the flip-flop circuits for the necessary number of consecutive blocks or more, that is, completes the reading and then completes the writing. It is determined whether or not a free space holding state is indicated. If the required number of blocks or more are in the free area holding state, the data is read from the track and written to the reproduction data memory 64. On the other hand, when the required number of blocks in the free space holding state does not exist, the reading from the optical disk and the writing to the reproduction data memory 64 are interrupted until the optical disk makes one revolution and the next read timing arrives. Has become.

As in the recording system, the data amount that can be recorded in the 0th track area at the innermost circumference of the optical disk is “A”, and the recording data amount increases by ΔA as the track number increases by “1”. The recording data amount “B” of the m-th track area is “A + ΔA × m”, and the data amount “B” of the outermost periphery is smaller than 2A.

Therefore, after the completion of the reading, if there are three consecutive blocks in the free space holding state in which the writing of the data has not been completed yet, the data read from the next track can be written in the reproduction data memory 64. No overflow occurs. Therefore, the memory amount calculation track control unit 69 determines whether or not to interrupt reading from the track based on whether or not the block status display signal indicates a free space holding state (reset) for three or more blocks in succession. Control.

Next, the operation of the reproducing system of such an optical disk device will be described.

380 SB is read from the reproduction data memory 64 in one reading cycle. Reproduction data memory 14
Is assumed to have first to fifth blocks in units of 380 SB. Memory amount calculation traffic controller 69
Causes three or more consecutive blocks to have data read out from the optical disk when the free area is held, and causes the memory write control unit 65 to write the read data into the reproduction data memory 64.

The memory write control unit 65 sets a corresponding flip-flop circuit every time the writing of one block is completed. The memory read control unit 66 stores one block of data in the read data memory 64 every read cycle.
Are read out sequentially. When reading of one block is completed, the corresponding flip-flop circuit is reset. The reproduction data processing section 67 corrects an error in the read data and outputs the data as reproduction data 68.

When the timing to start reading from the next track arrives, the memory amount calculation track control unit 69 determines whether or not three consecutive blocks are in the free area holding state based on the block state display signal. Find out. When there are three consecutive blocks in the free area holding state, reading from the next track is performed. On the other hand, when reading from a track is started, if three consecutive blocks are not in the free space holding state, the reproduction data memory 64 may overflow during the operation of reading from this track. Therefore, the memory amount calculation track control unit 69 suspends the reading operation from the optical disk until the optical disk makes one rotation and the next read timing comes. Further, the optical head 67 is not moved.

FIG. 6 shows an example of each signal waveform in the reproducing system of the optical disk device shown in FIG.
The data (b in the figure) read from the reproduction data memory 64 is cyclically read from the first to fifth blocks at a fixed read cycle of 380 SB. The data amount of 380SB is represented by “A”, and the number appended to the letter “A” represents the block number.

The data read from the optical disk and written to the reproduction data memory 64 (FIG. 7A) is 400 SB per one track cycle. In the drawing, the data amount of 400 SB to be read is indicated by "B", and the track number is indicated by the number given in each read cycle. In the track cycle, the period marked with a cross mark x indicates the period during which reading from the track is interrupted.

While the write enable signals (c to g in FIG. 8) for the first to fifth blocks of the reproduction data memory 64 are at the low level, writing to the corresponding blocks is performed. While the read enable signals (h to l in the drawing) to the first to fifth blocks of the reproduction data memory 64 are at a low level, data is read from the corresponding blocks. The block status display signals (m to q in the figure) indicating whether the first to fifth blocks are in the free space holding state change to high level when the writing is completed, and read out all data in the block. Changes to a low level when is completed.

Since a maximum of 760 SB of data is read from one track, it is guaranteed that no overflow will occur when there are three consecutive blocks with free areas, so reading from the track is performed. . At time T ₂₁ starts reading the third track region 81, the third to block state indication signal of the fifth block (figure o, p, q) is at the low level, the three or more free space carrier status This indicates that a block exists. Therefore, read from the third track is performed from time T _21. 400 SB data read from the third track area 81 is written to the third block and the fourth block.

[0083] after the reading of the third track area 81, at time T ₂₂ starts reading from the fourth track region 82, a fourth, two block status indicating signal corresponding to a fifth block (figure p, Only q) is at the low level and does not exist for three consecutive blocks. Therefore, the period of time T ₂₃ from time T ₂₂ to the optical disc is next one rotation, reading from the optical disk is interrupted. The optical head is held at the position of the fourth track area.

During this time, the reading from the first block 91 is completed, and the corresponding block status display signal (m in FIG. 10) changes to low level. Therefore, at time T _23, the fourth,
Three blocks, the fifth and the first blocks, are in the free area holding state. Therefore, from time T ₂₃ is read in the fourth track area 82 is performed, data read in the blocks are written. Thereafter, such an operation is repeated, and a reproducing operation from the optical disk is performed.

The period for writing one block of data to the reproduction data memory 64 is shorter than that for reading one block of data from the reproduction data memory 64 in CWL (constant recording wavelength). This is because the speed of the write clock to the reproduction data memory 64 increases according to the reproduction data amount.

In the optical disk apparatus described so far, recording and reproduction are performed at a constant recording wavelength by rotating the optical disk at a constant angular velocity and changing the clock speed of recording or reproduction. The wavelength may be constant. In this case, the reading cycle from the recording data memory changes in the recording system, and the writing cycle to the reproduction data memory changes in the reproducing system. Also, in the recording system shown in FIG. 1, the condition that the read cycle is earlier than the write cycle is set, but the read cycle is longer than the write cycle in the recording system with a constant linear velocity, and the write cycle is shorter in the reproduction system. Each may be longer than the period. However, since the clock rate does not change, an overflow or an underflow does not occur in the actual recording or reproducing operation.

In the embodiment described above, the recording data memory or the reproduction data memory is divided into five blocks and managed. However, the number of these blocks is such that the maximum amount of data to be stored in one track is stored. It is only necessary that the number of blocks be equal to or larger than the maximum number of blocks that can occur. Further, the recording data memory and the reproduction data memory do not necessarily have to be divided into block units. That is, in the recording system, it may be determined whether or not the recording on the track is to be interrupted based on whether or not data larger than the recording data amount of the track to be written next is prepared in the recording data memory.

At this time, it is determined whether or not the data amount in the recording data memory is equal to or larger than the reference value, based on the maximum recording data amount that can be recorded on one track (the data amount of the outermost track). You may. This eliminates the need to manage the amount of recording data for each track, thereby simplifying the configuration of the determination circuit.

In the case of the reproducing system, it is sufficient to determine whether or not there is a free area in the reproducing data memory equal to or larger than the recording data amount of the next track to be read, and to interrupt reading from the optical disk. Also in this case, if the maximum data amount read from one track (the data amount of the outermost track) is used as a reference, it is not necessary to manage the difference in the data amount for each track.

Although the recording data memory and the reproduction data memory are of a ring buffer type in the embodiment, a first-in first-out (FIFO) memory may be used.
In this case, a counter is provided which is incremented by "1" each time one block is written and decremented by "1" each time one block is read, and the interruption is determined based on whether or not the count value of the counter is equal to or more than the required number of blocks. What should I do?

[0091]

As described above, according to the first aspect of the present invention, when data larger than the data amount to be recorded on one track of the optical disk is not prepared in the recording data memory, the writing operation to the next track is performed. Has been interrupted. This makes it possible to control writing on the optical disk so that underflow does not occur during recording of one track. Further, since the block is used as a unit, it is possible to easily determine whether or not to interrupt, to shorten the processing time for the determination, and to simplify the configuration of the determination circuit.

According to the second aspect of the present invention, when there is no free area in the reproduction data memory larger than the data amount read from one track of the optical disk, reading from the optical disk to the reproduction memory is interrupted. This makes it possible to control reading and reproduction from the optical disk so that overflow does not occur during reading of one track. Also, since the unit is a block,
It is possible to easily determine whether or not to interrupt, to shorten the processing time for the determination, and to simplify the determination circuit.

Further, according to the third and fourth aspects of the present invention, since it is determined whether or not to interrupt based on the data amount itself, the required data amount or the required free space can be accurately determined. . For this reason, the margin of the recording data memory and the reproduction data memory can be set small, and a small capacity memory can be used.

According to the fifth aspect of the present invention, since the determination is made based on the maximum value that can be recorded on one track,
Since it is not necessary to identify the recording data amount for each track, it is possible to easily determine the interruption, and the configuration of the determination circuit can be further simplified.

Further, according to the sixth aspect of the invention, the recording wavelength is kept constant by making the rotation of the optical disk constant and the clock speed variable. In such an optical disk device, the amount of data recorded on each track changes for each track. However, since the interruption of access is determined based on the presence or absence of data exceeding the required amount or the presence or absence of an empty area, underflow or It is possible to control reading from and writing to the optical disk without overflow.

According to the seventh aspect of the present invention, there is provided an optical disk apparatus for recording / reproducing with a constant clock and changing the rotation speed of the optical disk so as to have a constant linear velocity to keep the recording wavelength constant. I do. Even in such an optical disk device, the interruption of the access to the optical disk is determined based on the presence or absence of data exceeding the required amount or the presence or absence of the free space exceeding the required amount. You can control reading and writing.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an outline of a configuration of a recording system of an optical disc device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a state in which data recorded on one track spans two blocks.

FIG. 3 is an explanatory diagram showing an example of a state in which data recorded on one track extends over three blocks.

FIG. 4 is a waveform chart showing an example of each signal waveform in a recording system of the optical disk device shown in FIG.

FIG. 5 is a block diagram showing an outline of a configuration of a reproducing system of the optical disc device in one embodiment of the present invention.

6 is a waveform chart showing an example of each signal waveform in a reproduction system of the optical disk device shown in FIG.

FIG. 7 is a block diagram showing a configuration of a recording system of an optical disk apparatus that rotates an optical disk at a constant angular velocity and records data at a constant recording wavelength, which is conventionally used.

FIG. 8 is a block diagram showing a configuration of a reproducing system of an optical disk device that conventionally rotates an optical disk at a constant angular velocity and records data at a constant recording wavelength.

[Explanation of symbols]

 11, 61 Optical disk device 12 Input data 13 Record data processing unit 14 Record data memory 15, 65 Memory write control unit 16, 66 Memory read control unit 17, 62 Optical head 18, 63 Head drive unit 19, 69 Memory amount calculation track Control unit 64 Playback data memory 67 Playback data processing unit 68 Playback data

Claims (7)

(57) [Claims] 1. A recording data memory provided with a plurality of storage areas of a predetermined size for temporarily storing data to be recorded on an optical disk, writing means for sequentially writing data to the recording data memory at a constant speed, When data recording is started on any one track of the optical disk, the amount of data that can be written on one track by the written storage area in which all or part of the data has not been read yet is determined. Divide by the specified size and round up below the decimal point to 1
Determining means for determining whether or not there is more than the required number, and determining whether or not a written storage area having unread data in all or a part of the storage area is more than the required number. When read, data is read from the recording data memory and written to the optical disk. A disk writing means, and the written storage area in which all or a part of the data which has not been read out by the determination means has the data. When it is determined that there is no more than the required number,
An optical disk device comprising: a disk write interrupting unit for interrupting reading of data from the recording data memory and writing of data to the optical disk until the next writing start time comes. 2. A reproduction data memory including a plurality of storage areas of a predetermined size for temporarily storing data read from an optical disk, reading means for sequentially reading data from the reproduction data memory at a constant speed, and the optical disk. When data reading is started from any one of the tracks, the necessary number obtained by dividing the amount of data read from one track by the predetermined size in the empty storage area and adding 1 to a value obtained by rounding up the decimal point. Discriminating means for discriminating whether or not the disc is present; and when the discriminating means discriminates that the number of empty storage areas is equal to or more than the required number, data is read from one track of the optical disc and read out from the reproduction data memory. Disk reading means to be stored in the storage area, and the storage area in an empty state by the determination means is equal to or more than the required number. Means for interrupting the reading of data from the optical disk and the writing of data into the reproduction data memory until the next reading start time arrives when the optical disk makes one revolution when it is determined that the disk does not exist; An optical disc device characterized by the above-mentioned. 3. A recording data memory for temporarily storing data to be stored on an optical disk; writing means for sequentially writing data to the recording data memory at a constant speed; Discriminating means for judging whether or not data larger than the data amount to be recorded on the track when data recording is started is present in the recording data memory; When it is determined that the data exists in the memory, data is read from the recording data memory and the disk writing means writes the data to the optical disk, and the determining means determines that the data having the data amount or more does not exist in the recording data memory. The optical disk makes one revolution and the recording data memory is stored until the next writing start time comes. An optical disk apparatus comprising: a disk write interrupting unit that interrupts reading of data from a disk and writing of data to an optical disk. 4. A reproduction data memory for temporarily storing data read from an optical disk; reading means for sequentially reading data from the reproduction data memory at a constant speed; and data from any one track of the optical disk. Discriminating means for judging whether or not there is an empty area in the reproduction data memory equal to or more than the data amount read from the track when the reading of the track is started; and judging by this judging means that there is an empty area equal to or more than the data amount. When read, data is read from the track of the optical disc and the read data is stored in the reproduction data memory. The discrimination means discriminates that the reproduction data memory does not have a free area larger than the data amount. When the optical disk makes one round, light is emitted until the next read start time arrives. Optical disk apparatus characterized by comprising a disk reading interruption means for interrupting the writing of data to read and the reproduction data memory of the data from the disk. 5. The data amount of one track used as a criterion for the discrimination by the discriminating means is a data amount of a track having the largest data amount that can be recorded among tracks provided on the optical disc. 5. The optical disk device according to claim 1, wherein: 6. The optical disc is rotated at a constant angular velocity, and data is recorded at a constant recording wavelength by increasing a clock frequency, which is a reference of data reading / writing speed, according to a track radius. 5. The optical disk device according to claim 1, wherein: 7. The optical disk, in which data is read and written in accordance with a clock having a constant frequency, and data is recorded at a constant recording wavelength by changing a rotation speed so as to keep a linear velocity constant. 5. The optical disk device according to claim 1, wherein: