JPH09251712A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of controlling access to an optical disk so as not to cause overflow and underflow in a buffer memory having simple circuit constitution. SOLUTION: When write-in to a next track is started, whether or not the data of a maximum recording data amount or above of one track on an optical disk exist in a buffer memory 14 is discriminated in a unit of blocks. When the blocks storing the data exist more than required ones, the write-in to the track is performed, and when not, the write-in is interrupted. At a reproducing time, when a free area for more than the data amount read out from one track doesn't exist in the buffer memory 14, the read-out from the optical disk is interrupted. When the blocks more than required ones don't exist, the access is interrupted, so that the underflow and the overflow don't occur while one track is under recording/reproducing. Further, since the blocks are used as a unit, constitution of a discriminant circuit is simplified.

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 / 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 same amount of data is recorded on each track, 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 it approaches the outer circumference. The other is to keep the frequency of the recording clock constant and decrease the rotation speed of the optical disk as the position of the track to be read and written approaches the outer circumference so that the recording wavelength becomes constant.

FIG. 7 shows a structure of a recording system of an optical disk device which has been used conventionally and which 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 data string of a unit amount called a sync block, and a recording data memory 104 that temporarily stores a sync block to be written on an optical disc. There is.

A memory write control unit 105 for writing the data output from the print data processing unit 103 to the print data memory 104 and a memory read control unit 10 for controlling the read of the data stored in the print data memory 104.
6. Further, an optical head 107 for writing the read data on the optical disc, a head drive 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.

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

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

In order to keep the recording wavelength constant, the speed of the recording clock is increased as the track gets closer to the outer circumference, and the reading speed from the recording data memory 104 becomes faster. As a result, the recorded data amount of ΔA increases each time the track number increases by “1”. M-th (m is n> = m> =
The data amount recorded on the track (track number indicated by 0) is “A + ΔA × m”. Recording data memory 1
Since the amount of data written in 04 is “A” during the input cycle in which the optical disc makes one rotation, when data is recorded in the m-th track of the optical disc, the amount of data in the recording data memory 104 during the period of recording one track. Is “ΔA
Xm "is reduced.

Therefore, if recording is continued on tracks other than the 0th track, the amount of data in the recording data memory 104 gradually decreases and underflow occurs. In order to prevent this, the data amount calculation track control unit 109
Is the amount of data “A” written in the recording data memory 104 and the amount of data “A + ΔA ×” recorded on the optical disc.
The difference from m ”is sequentially integrated. Then, each time the integrated value reaches the data amount“ A ”, the reading operation from the recording data memory 104 and the recording operation on the optical disc are interrupted for a period of one track. ing.

For example, assuming that the amount of data in one field is 380 SB, memory write control unit 105.
Thus, 380 SB of data is stored in the recording data memory 104 for each field. Further, it is assumed that data of 380 SB only is recorded in the 0th track area of the innermost circumference, and the recorded 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 is equal to the amount of data recorded on the optical disc, so the integrated value of the difference remains “0”, and a constant repetition is performed without interruption. Recording on the optical disk is performed in a cycle.

However, when recording on the first track area, only 384 SB of data is read from the recording data memory 104 during the period of one track, and the accumulated amount decreases 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 differences reaches 380 SB, that is, when recording is performed in the first track area, the recording data memory 1 is recorded only once every 95 tracks of recording.
Reading from 04 is suspended. Similarly, when the data is recorded in the track areas of other numbers, the integrated value of the difference is 380S.
The recording is interrupted only for one track period each time the recording medium B is reached. The insufficient 380 SB worth of data is replenished while the recording is suspended, thus preventing underflow.

FIG. 8 shows a structure of a reproducing system of an optical disk device which has been used conventionally and which rotates an optical disk at a constant angular velocity and records data at a constant recording wavelength. The optical disc device 121 includes an optical head 122 for reading data from an optical disc, a head drive unit 123 for driving the optical head 122, a reproduction data memory 124 for temporarily storing the read data, and a read data. A memory writing control unit 125 for writing in 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 constant output cycle. The reproduction data processing unit 127 extracts the data portion from the sync block read from the reproduction data memory 124, corrects the data error based on the error correction code, and outputs the reproduction data 128. The data amount calculation track control unit 129 controls the reproduction data memory 124.
It is a circuit that determines whether or not the reading of the next track should be interrupted based on the integrated value of the difference between the amount of data read from and the amount of data written.

The recording area of the optical disk is the same as in the case of the recording system, from the innermost track 0th track to the outermost nth track (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 the position approaches the outer circumference. M-th (m is n>
= M> = 0) The amount of data read from the track is “A + ΔA × m”. Also,
Data of only "A" is read from the reproduction data memory 124 in a constant output cycle, and the output cycle coincides with the track rotation cycle.

When data is read from the mth track and written in the reproduction data memory 124, the amount of data in the reproduction data memory 124 is "ΔA ×" while reading one track.
Therefore, when the reproduction from the tracks other than the 0th track is continued, the reproduction data memory 1 gradually increases.
The amount of data in 24 increases and overflow occurs.

In order to prevent this, the data amount calculation track control unit 129 controls the data amount “A” read from the reproduction data memory 124 and the data amount “A + ΔA read from the optical disk and written in the reproduction data memory 124.
Xm "is sequentially integrated, and each time the data amount reaches" A ", the reading operation from the optical disk and the writing operation to the reproduction data memory 124 are interrupted for a period of one track. There is.

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

However, when the first track area is reproduced, the reproduction data memory 124 can store three tracks during one track period.
Data of 84 SB is written, and the accumulated 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 differences reaches 380 SB, that is,
When the first track area is reproduced, the read operation from the optical disk and the write operation to the reproduction data memory 124 are interrupted only once every 95 tracks are reproduced. Since the excess 380 SB worth of data is read while the reproduction is suspended, overflow is prevented.

[0019]

In the optical disk device described above, when the integrated value of the difference between the input and the output reaches the data amount "A" of one cycle, the access to the optical disk is interrupted 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 access to the optical disc can be controlled by the operation of integrating the difference, but if the cycles are different, should the access to the optical disc be interrupted based on the result of such computation? I can't judge whether or not.

For example, if the amount of data written in 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 differences 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 disc is stopped when the integrated value of the differences reaches 380 SB, the amount of data accumulated in the recording data memory gradually decreases and an underflow occurs.

Further, in order to calculate the integrated value and compare the calculated value with the reference data amount, it is necessary to use circuit elements such as an adder and a comparator, which increases the circuit scale and causes the calculation. There is a problem that it takes a long time and is not suitable for high speed operation.

Therefore, an object of the present invention is to provide an optical disk device having a simple 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 a first aspect of 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 disc,
There is a writing means for sequentially writing data in the recording data memory at a constant speed, and all or some of the data which has not yet been read out when data recording is started on any one track of the optical disk. A discriminating means for discriminating whether or not there is a required number of written storage areas by dividing the amount of data that can be written in one track by a predetermined size and adding 1 to the value obtained by rounding up the decimal point and below. Disc writing means for reading data from the recording data memory and writing the same on the optical disc when the discriminating means discriminates that there is a required number or more of written storage areas in which all or part of the data has not yet been read out In addition, it is necessary to have a written storage area in which all or part of the data has not been read by the discriminating means. When it is discriminated that there are not more than a certain number of discs, the optical disc makes one revolution and the disc write interruption means for interrupting the reading of data from the recording data memory and the writing of data to the optical disc until the next writing start time comes. It is equipped in the device.

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 amount of data to be recorded on one track of the optical disk is prepared in the recording data memory. It is determined as a unit. When the number of blocks in which the data is stored is greater than or equal to the required number, writing to the track is performed, and when the number of blocks is less than or equal to the required number, writing is suspended. When there are not more than the required number of blocks, recording is interrupted, and therefore underflow does not occur during recording of one track. Further, 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 the data read from the optical disk, and data is sequentially read from the reproduction data memory at a constant speed. When the reading means and the reading of data from any one track of the optical disk are started, the storage area in the empty state is 1
The amount of data read from one track is divided by a predetermined size to determine whether or not there is more than a required number obtained by adding 1 to the value obtained by rounding up the decimal point and rounding down the decimal point. When it is determined that there are more than the required number of discs, the disc reading means for reading data from one track of the optical disc and storing the data in the reproduction data memory, and the number of discriminating means determines that the required number of free storage areas does not exist. When it is determined, the optical disk device is equipped 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 invention, when the reading is started from the next track, it is determined whether or not there is a free area in the reproduction data memory which is equal to or larger than the amount of data read from one track of the optical disk. Is determined as. Then, when there are more than the required number of blocks in the empty state, read from this track,
Reading is suspended when there are not more than the required number. When there is not more than the required number of empty blocks, the reading from the optical disk to the reproduction memory is interrupted, so that the reproduction data memory does not overflow during the reading of one track. Further, since the block is used as a unit, the determination can be easily performed.

According to a third aspect of the invention, a recording data memory for temporarily storing data to be recorded on the optical disc,
A writing means for sequentially writing data to the recording data memory at a constant speed, and a recording data memory having a data amount equal to or larger than the amount of data recorded on the track when data recording is started on any one track of the optical disk. Discriminating means for discriminating whether or not it exists in the recording data memory, and disc discriminating means for reading out the data from the recording data memory and writing the same on the optical disc when the discrimination device judges that the data of the data amount or more exists in the recording data memory. When the area number discriminating means discriminates that the data amount more than the data amount does not exist in the recording data memory, the optical disc makes one round and the data is read from the recording data memory and is written to the optical disc until the next writing start time comes. And a disk write interrupting means for interrupting the writing of the data in the optical disk device. It is made to.

That is, according to the third aspect of the invention, when the 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 the track. When more than the required amount of data exists in the recording data memory, writing to the track is performed, and when less than the required amount of data, writing is interrupted. When there is no more data than the required amount, recording is interrupted, so underflow does not occur during recording on one track. Further, it is complicated to determine whether or not to interrupt the processing in units of blocks, but since it is based on the data amount itself, accurate determination can be performed.

According to the fourth aspect of the present invention, a reproduction data memory for temporarily storing data read from the optical disk, a reading means for sequentially reading data from the reproduction data memory at a constant speed, and an arbitrary optical disk are provided. 1
When starting to read data from one track, there is a discriminating means for discriminating whether or not there is a vacant area equal to or larger than the data amount read from the track in the reproduction data memory, and a vacant region equal to or larger than the data amount is present by this discriminating means. Then, when it is determined that the data is read from the track of the optical disc and is stored in the reproduction data memory, the disc reading means, and when the determination means determines that the reproduction data memory does not have an empty area equal to or more than the data amount, the optical disc is 1 The optical disk device is provided with a disk read interrupting 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 is reached.

That is, in the invention described in claim 4, when reading is started from the next track, it is judged whether or not there is a free area in the reproduction data memory which is equal to or larger than the amount of data read from one track of the optical disk. There is.

In the fifth aspect of the invention, the amount of data that serves as a reference for determining whether or not to interrupt is the maximum value of the amount of data that can be recorded on one track of the optical disc.

That is, according to the fifth aspect of the invention, the recording is interrupted when there is no more than the maximum amount of data that can be recorded in one track in the recording data memory. Further, when there is no empty area equal to or larger than the maximum amount read from one track in the reproduction data memory, the reading from the optical disk is interrupted. As described above, since the determination is made 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 determination can be easily performed.

According to a sixth aspect of the present invention, the optical disk is rotated at a constant angular velocity, and the frequency of a clock serving as a reference for the speed of reading and writing data increases according to the radius of the track, so that data is recorded at a constant recording wavelength. Is recorded.

According to a seventh aspect of the present invention, data is read from and written to the optical disc in accordance with a clock having a constant frequency, and the rotation speed is changed so that the linear velocity becomes constant, whereby the data is recorded at a constant recording wavelength. It will be recorded.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 the optical disk at a constant angular velocity and increases the recording clock speed as the track approaches the outer circumference. As a result, recording is performed at a constant recording wavelength. Therefore, the amount of recording data recorded on one track increases as the position approaches the outer circumference. Further, the recording area of the optical disk is from the 0th track on the innermost track to the nth track (n is 1) on the outermost track.
It is composed of n + 1 concentric track areas up to (the above integer) tracks.

The optical disk device 11 includes a recording data processing unit 13 for converting the input data 12 to be recorded into a data string of sync blocks, a recording data memory 14 for temporarily storing the sync blocks to be written on the optical disk, and recording data. The memory write control unit 15 is provided for writing the data output from the processing unit 13 into the recording data memory 14.
Further, a memory read control unit 16 for controlling the reading of data from the recording data memory 14, an optical head 17 for writing data on the optical disk, a head drive unit 18, and a calculation as to whether or not writing to the track should be interrupted. A memory amount calculation track control unit 19 is provided.

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

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

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

The memory amount calculation track control unit 19 is provided with a flip-flop circuit (not shown) for each block. When the write completion signal 21 of the corresponding block is input, the flip-flop circuit is set to complete the 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 called block state display signals.

When the memory amount calculation track control unit 19 starts writing to the next track, the flip-flop circuit for the required number of blocks consecutive from the first stored block of the data to be written to this track is required. It is determined whether or not is set. Then, when the required number of blocks or more is in the writing completed state, the data is read from the recording data memory 14 and recording is performed on the corresponding track.

On the other hand, when there are not more than the required number of blocks in the write completed state, the recording data memory 14 is rotated until the optical disk makes one rotation and the next write timing arrives.
The reading of data from the optical disc and the recording of the data on the optical disc are interrupted.

It is assumed that the amount of data that can be recorded in the 0th track area of the innermost circumference of the optical disk is "A", and that the amount of data that can be recorded in that track increases by ΔA each time the track number increases by "1". At this time, the recording data amount “B” in 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 distributed and stored in three blocks. Therefore, if there are three consecutive blocks in the write-completed state in which the reading of the data has not been completed after the writing is completed, the 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 stop recording on the track, based on whether or not the block status display signals of three or more consecutive blocks indicate the write completion status. ing.

Further, the write cycle (field cycle) to the recording data memory 14 and the read cycle (track cycle) corresponding to one rotation of the optical disk do not coincide with each other and are arbitrary cycles. However, the read cycle needs to be shorter than the write cycle. The amount of data read from the recording data memory 14 within one read cycle is the smallest when recorded in the 0th track area of the innermost circumference.
Since it is assumed that the data amount "A" is equal to the data amount "A" written in the recording data memory 14 during one writing cycle, the recording data memory 14 will be stored even after an infinite time elapses. In order not to 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 in the recording data memory 14 in one writing cycle is 380 SB. Further, the recording data memory 14 is divided into a plurality of blocks in units of 380 SB and managed. 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, and the memory writing control unit 15
Converts the sync block after conversion into 380 S for each write cycle.
Each B is sequentially written in the recording data memory 14.

The data write destination moves to the next block for each write cycle, and five blocks are cyclically used. The memory write control unit 15 sets the corresponding flip-flop circuit of the memory amount calculation track control unit 19 every time 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 head data is stored are in the write completed state. Whether or not it is checked based on the block status display signal. When three blocks continuously indicate the write completion state, the memory read control unit 16 outputs a read instruction of data to be recorded in the next track. 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 the reading of all the data in one block is completed, the memory read control unit 16 outputs a read completion signal 22 for that block. In response to this, 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 the write completed state, there is a possibility that data may underflow during the writing operation to this track. Therefore, the memory amount calculation track control unit 19 does not output the read instruction and interrupts the recording operation on the optical disk until the optical disk makes one rotation and the next write timing arrives. Further, 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 amount of data written in the recording data memory 14 in one writing cycle is 380 SB.
The case where the amount of data read from the recording data memory 14 in one read cycle is 400 SB is shown. Further, the recording data amount of one track increases every 10 tracks.

The 400 SB data 21 to be recorded on the first track starts from the beginning of the first block 22. Therefore, the data of 400 SB to the first track is 380 SB of the first block 22 and the second block 2 of 380 SB.
It is stored across 20 SBs at the head of No. 3.
360S of the data 24 recorded on the second track
B is stored in the second block 23, and the remaining 40 SB is stored in the third block 25. Similarly, 340SB of the data 26 recorded on the third track is the third
The remaining 60 SBs are stored in the block 25 and in the fourth block 27, respectively.

As described above, in addition to the case where the recording data amount of the track is stored over two blocks, there are cases where the data is over three blocks. For example, 12 SB is stored in the first block, 380 SB is stored in the second block, and the remaining 8 SB is stored in the third block.

FIG. 3 shows an example in which data recorded on one track exists 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 SBs are separately stored in the fourth block 34. The maximum recording data amount of one track is 76
Since it is 0SB, it does not span more than three blocks. Therefore, if three consecutive blocks are in the write completed state, it can be guaranteed that no data underflow occurs during 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 written in the recording data memory 14 (a in the same figure)
Is 3 in a cyclically constant write cycle in the first to fifth blocks.
80 SB is written for each. In the figure, the data amount of 380 SB is represented as "A". The number added after the letter "A" represents the block number.

The data read from the recording data memory 14 (b in the figure) is 400 SB per read cycle (track cycle). 40 read in the figure
The data amount of 0SB is expressed as "B". Further, the number given in each read cycle indicates a track number. In the read cycle, the period marked with a broken line represents the period in which recording on the track is suspended.

While the write enable signal (c to g in the figure) to the first to fifth blocks of the recording data memory 14 is at the low level, writing to the corresponding block is performed. While the read enable signals (h to l in the figure) to the first to fifth blocks of the recording data memory 14 are at the low level, the data is read from the corresponding blocks. The block state display signals (m to q in the figure) indicating whether or not the first to fifth blocks are in the write completion state change to a high level when the writing is completed, and all the data in the block are read out. Changes to low level when is completed.

At time T ₁₁ , the write enable signal (c in the figure) becomes low level, and writing of data to the first block 41 is started. At time T ₁₂ when the writing to the first block 41 is completed, the block state display signal (m in the figure) of the first block changes to the high level. Similarly, every time the writing of the second and third blocks 42 and 43 is completed, the block state display signals (n and o in the figure) corresponding to these write signals become high level.

At time T ₁₃ , the block status display signals corresponding to the first to third blocks are all set to the high level, and the memory amount calculation track control unit 19 confirms that the data has been prepared in three consecutive blocks. recognize. Therefore, writing to the optical disc is started from time T ₁₃ . Time T
_{From 13} to time T ₁₄ , the first block 41 to 380S
The data of B is read, and the data of 20 SB is read from the second block 42 from time T ₁₄ to time T ₁₅ . The data read from the first and second blocks 41 and 42 is recorded in the first track area 51 of the optical disc.

A period of writing one block of data into the recording data memory 14, for example, a period of reading one block of data from the recording data memory 14 (time T ₁₃ to time T ₁₂ compared to the length of time T ₁₁ to time T ₁₂ ). The length of time T ₁₄ ) is short. This is because the track period is shorter than the writing period, and since the recording is performed on the optical disc at a constant recording wavelength, the clock speed becomes faster according to the recording data amount of the track.

Since the reading of all the data of the first block 41 is completed at the time T ₁₄ , the corresponding block state display signal (m in the figure) is reset to the low level. Although a part (20 SB) of the second block has already been read, the reading of the remaining 360 SB has not been completed, and therefore remains in the high level state at the time when the recording on the first track area is completed. .

At time T ₁₅ when recording on the first track area is completed, 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, which is less than three blocks. Therefore, the memory amount calculation track control unit 19 suspends the reading of data from the recording data memory 14 and the writing to the optical disc in the next track cycle from time T ₁₅ to time T ₁₆ . Further, the optical head 17 is held at the position of the second track.

During this time, since the writing of the fourth block 44 is completed, at time T ₁₆ after the optical disk makes one round, the three consecutive blocks are in the writing completed state again. Therefore, the memory amount calculation track control unit 19
Recording from the time T ₁₆ on the second track area 52 is started. 360 SB read from the second block and 40 SB read from the third block are recorded in the second track area 52. Recording on the optical disk is sequentially performed by repeating such an operation.

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

FIG. 5 shows an outline of the structure of the reproducing system of the optical disk device. This optical disk device rotates the optical disk at a constant angular velocity as in the recording system, and the speed of the reproduction clock is increased as the track approaches the outer circumference.

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

The memory read control unit 66 is a circuit for reading data from the reproduction data memory 64 in a constant output cycle. The reproduction data processing unit 67 includes a reproduction data memory 6
The data portion is extracted from the sync block read from the data No. 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 calculates whether or not to interrupt the reading from the track.

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

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

When the memory amount calculation track control unit 69 starts reading from the next track, the flip-flop circuits for a necessary number of consecutive blocks or more are in the reset state, that is, the writing is completed after the reading is completed. It is determined whether or not there is a free area holding state that is a non-existent state. If the required number of blocks is in the free area holding state, the reading from the track is performed and the writing to the reproduction data memory 64 is performed. On the other hand, when there are not more than the required number of blocks in the free space holding state, the reading from the optical disc and the writing to the reproduction data memory 64 are suspended until the next reading timing comes. Has become.

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

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

Next, the operation of the reproducing system of such an optical disc apparatus will be described.

380 SB is read from the reproduction data memory 64 in one read cycle. Playback data memory 14
Includes first to fifth blocks in units of 380 SB. Memory amount calculation traffic control unit 69
When three or more consecutive blocks are in a free space holding state, data is read from the optical disc and the read data is written in the reproduction data memory 64 by the memory writing control unit 65.

The memory write controller 65 sets the corresponding flip-flop circuit each time writing of one block is completed. The memory read control unit 66 reproduces one block of data for each read cycle from the reproduction data memory 64.
Are sequentially read from. When the reading of one block is completed, the corresponding flip-flop circuit is reset. The reproduction data processing unit 67 corrects an error in the read data and then outputs the 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 empty area holding state based on the block state display signal. Find out. When there are three consecutive free area holding blocks, reading from the next track is performed. On the other hand, when the reading from the track is started, if the continuous three blocks are not in the empty area holding state, the reproduction data memory 64 may overflow during the reading operation from the 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 by 380 SB at a constant read cycle. The data amount of 380 SB is "A", and the number added after the character "A" represents the block number.

The data read from the optical disk and written in the reproduction data memory 64 (a in the figure) is 400 SB per track cycle. In the figure, the data amount of 400 SB to be read is shown as "B", and the track number is shown by the number given in each read cycle. In the track cycle, a period marked with a broken line X represents a period in which reading from the track is interrupted.

While the write enable signal to the first to fifth blocks of the reproduction data memory 64 is low level, writing to the corresponding block is performed. While the read enable signal (h to l in the figure) to the first to fifth blocks of the reproduction data memory 64 is at the low level, data is read from the corresponding block. The block state display signals (m to q in the figure) indicating whether or not the first to fifth blocks are in the empty area holding state change to high level when the writing is completed, and all the data in the block are read out. Changes to 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 in the free space holding state, so that reading from the track is performed. . At the time T _{21 when} the reading of the third track area 81 is started, the block state display signals (o, p, q in the same figure) of the third to fifth blocks are at the low level, and there are three or more empty area holding states. It indicates that there is a block. Therefore, read from the third track is performed from time T _21. The 400 SB data read from the third track area 81 is written in the third block and the fourth block.

At time T ₂₂ when the reading from the third track area 81 is finished and the reading from the fourth track area 82 is started, two block state display signals (p in FIG. Only q) is at a low level, and there are no consecutive 3 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 state display signal (m in the figure) changes to the low level. Therefore, at time T ₂₃ , the fourth,
Three blocks, the fifth block and the first block, are in a free space holding state. Therefore, the reading of the fourth track area 82 is performed from time T _23, and the read data is written in these blocks. After that, such an operation is repeated and a reproducing operation from the optical disk is performed.

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

In the optical disk device described so far, the optical disk is rotated at a constant angular velocity and the recording / reproducing clock speed is changed to perform recording / reproducing at a constant recording wavelength, but recording is performed at a constant linear velocity. The wavelength may be fixed. 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. In the recording system shown in FIG. 1, the read cycle is faster than the write cycle. However, the read cycle is faster than the write cycle in the constant linear velocity recording system and the read cycle is faster in the reproducing system. Each may be longer than the cycle. However, since the clock rate does not change, overflow or underflow does not occur in the actual recording or reproducing operation.

In the above-described embodiment, the recording data memory or the reproduction data memory is divided into five blocks and managed. However, the number of blocks is such that the maximum amount of data stored in one track is stored. It may be greater than the maximum number of blocks that may occur. Also, the recording data memory and the reproduction data memory do not necessarily have to be divided into blocks. That is, in the recording system, it may be determined whether or not the recording on the track should be interrupted depending on whether or not the recording data memory has more data than the recording data amount of the track to be written next.

At this time, it is determined whether or not the amount of data in the recording data memory is greater than or equal to this reference value with reference to the maximum amount of recording data that can be recorded on one track (the amount of data on the outermost track). May be. As a result, it is not necessary to manage the recording data amount for each track, and the configuration of the determination circuit can be simplified accordingly.

In the case of a reproducing system, it is sufficient to determine whether or not there is a free area in the reproduced data memory that is equal to or more than the recording data amount of the track to be read next, and interrupt the 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 becomes unnecessary to manage the difference in the data amount for each track.

Further, although the recording data memory and the reproduction data memory are of the 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 depending on whether the count value of the counter is equal to or more than the required number of blocks. You can do it like this.

[0091]

As described above, according to the first aspect of the present invention, when the recording data memory does not have more data than the amount of data recorded in one track of the optical disk, the writing operation to the next track is performed. It's suspended. This makes it possible to control writing on the optical disc so that underflow does not occur during recording on one track. Further, since the block is used as a unit, it is possible to easily determine whether or not to interrupt, the processing time for the determination can be shortened, and the configuration of the determination circuit can be simplified.

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

Further, according to the third and fourth aspects of the present invention, since it is determined whether or not the interruption is performed based on the data amount itself, the required data amount or the required free space can be accurately determined. . Therefore, 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 invention, the determination is made 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, the interruption can be easily discriminated, and the configuration of the discrimination circuit can be further simplified.

Further, according to the invention of claim 6, the recording wavelength is made constant by rotating the optical disk at a constant angular velocity and by making the clock speed variable. In such an optical disk device, the amount of data recorded on each track changes from track to track. However, since access interruption is determined based on the presence or absence of data in excess of the required amount or the presence or absence of free areas, underflow and It is possible to control reading and writing on the optical disk without overflow.

According to a seventh aspect of the present invention, an optical disk device is provided which makes the recording wavelength constant by recording / reproducing at a constant clock and changing the rotation speed of the optical disk so as to obtain a constant linear velocity. I am. Even with such an optical disc device, since interruption of access to the optical disc is determined based on the presence or absence of data of a required amount or the presence or absence of a vacant region of a required amount or more, it is possible to write to the optical disc without underflow or overflow. You can control reading and writing.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a configuration of a recording system of an optical disc device in 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 is spread over three blocks.

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

FIG. 5 is a block diagram showing an outline of a configuration of a reproduction 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 disc device shown in FIG.

FIG. 7 is a block diagram showing a configuration of a recording system of an optical disc device which is conventionally used and rotates an optical disc at a constant angular velocity to record data at a constant recording wavelength.

FIG. 8 is a block diagram showing a configuration of a reproducing system of an optical disk device which has been conventionally used and which 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 Recording data processing unit 14 Recording data memory 15, 65 Memory writing control unit 16, 66 Memory reading 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)

[Claims] 1. A recording data memory having a plurality of storage areas of a predetermined size for temporarily storing data to be recorded on an optical disc; a 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 data amount which can be written on one track by the written storage area having unread data in all or part thereof Divide by a predetermined size and round up to the nearest decimal point to 1
And a judgment means for judging whether or not there is more than the necessary number, and it is judged by this judgment means that there is more than the necessary number of written storage areas in which all or part of the data has not been read yet. When the data is written, a disc writing unit that reads data from the recording data memory and writes the data to the optical disc, and a written storage area that has data that has not been read by all or a part of the discriminating unit are described above. When it is determined that there are not more than the required number of optical disks, the number of optical disks is 1.
An optical disk device comprising: a disk write interrupting means for interrupting the reading of data from the recording data memory and the writing of data to the optical disk until the next write start time is reached. 2. A reproduction data memory having a plurality of storage areas of a predetermined size for temporarily storing data read from the optical disc, a reading means for sequentially reading data from the reproduction data memory at a constant speed, and the optical disc. When data reading is started from any one of the tracks, it is necessary to add 1 to the value obtained by dividing the amount of data read from one track of the empty storage area by the predetermined size and rounding up to the decimal point. A discriminating means for discriminating whether or not there are more than a necessary number, and when the discriminating means discriminates that there is a required number of storage areas or more, the data is read from one track of the optical disk and the read data is reproduced. The disk read means for storing in the memory, and the storage area in the empty state by the area number determination means Optical disc when it is determined that there is no main number or 1
An optical disk device comprising: a disk read interrupting 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 is reached. 3. A recording data memory for temporarily storing data to be recorded on an optical disc, a writing means for sequentially writing data to the recording data memory at a constant speed, and an arbitrary track on the optical disc. A discriminating means for discriminating whether or not the data amount more than the data amount recorded on the track when the data recording is started exists in the recording data memory, and the discriminating device determines that the data amount more than the data amount is the recording data Disc writing means for reading data from the recording data memory and writing the same on the optical disc when it is determined that the recording data memory exists, and that there is no more data than the data amount in the recording data memory by the area number determining means. When it is determined that the optical disk has completed one revolution, the recording data is recorded until the next writing start time Optical disk apparatus characterized by comprising a disk write interrupt means for interrupting the writing of the read and the data on the optical disk of the data from the memory. 4. A reproduction data memory for temporarily storing data read from an optical disc, a reading unit for sequentially reading data from the reproduction data memory at a constant speed, and data from any one track of the optical disc. Discriminating means for discriminating whether or not there is a vacant area equal to or larger than the data amount read from the track when starting the reading, and the deciding means discriminates that a vacant area equal to or larger than the data amount exists. And a disc reading means for reading data from the track of the optical disc and storing the data in the reproduction data memory, and the discriminating means discriminating that there is no free area equal to or larger than the data amount in the reproduction data memory. At this time, the optical disk makes one round and 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 determination by the determination means is the data amount of the largest recordable data amount of the tracks provided on the optical disk. 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 the frequency of a clock serving as a reference for the speed of reading and writing data according to the radius of a track. 5. The optical disk device according to claim 1, wherein: 7. The optical disk is for reading and writing data according to a clock having a constant frequency, and changing the rotation speed so that the linear velocity is constant, whereby data is recorded at a constant recording wavelength. The optical disk device according to any one of claims 1 to 4, wherein: