JP3505451B2 - Simultaneous recording and playback device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simultaneous recording / reproducing apparatus for recording a video / audio signal on a recording medium and performing chasing reproduction.

[0002]

2. Description of the Related Art Home video tape recorders (VTRs)
Is widely used and used in ordinary households. Home VTR
One of the main uses of the video recording is the reserved video recording, and the recording and reproduction of the video / audio signal is performed under the concept of time shift.

However, when the reserved recording is set in the home VTR, the recorded contents cannot be viewed before the end time of the reserved recording, for example. That is, there is a drawback that the recorded contents cannot be viewed until the reserved recording is completed. In order to solve such a problem, Japanese Patent Laid-Open No. 6-14288 proposes a method in which the contents being recorded can be freely viewed from the beginning before the end of the reserved recording. A method of freely viewing from the beginning of the recorded contents to the portion being recorded even during recording is generally called chasing reproduction.

On the other hand, as a recording method for a DVD-RAM or the like, a zone CLV (Constant Linear Vel) is used.
The ocracy) system (hereinafter referred to as ZCLV system) is adopted. The ZCLV method divides a recording medium into a plurality of areas (zones) in the radial direction, and the CAV (Consta
nt Angular Velocity) recording method. In addition, the number of revolutions is different between zones, and the number of revolutions becomes faster in the inner zone. That is, the ZCLV method is used because the linear velocity must be within a certain range because the range of the recording power margin at the time of recording is limited.

[0005]

However, the above conventional techniques have various problems as described below. If the buffer amount on the recording side overflows, the data to be recorded will be interrupted. Further, in order to perform the chasing reproduction, the speed of writing and reading the data to / from the medium must be higher than that in the case of only the reproduction. Further, when the reproduction position catches up with the recording position by high-speed reproduction or the like, it is not known that the user has caught up. Further, when the reproduction position catches up with the recording position, the reproduced image is disturbed.

Further, in a recording medium for recording by the ZCLV system or the CLV system, the optimum rotation speed differs depending on the recording position. However, in the above-mentioned conventional technique, when chasing reproduction is performed on such a recording medium, the number of rotations is different between the recording position and the reproducing position, and when the recording operation is changed to the reproducing operation (or vice versa). , And so on), it is necessary to change the rotation speed. When the number of rotations is changed, it takes time until the number of rotations stabilizes, and therefore it takes time before shifting from the recording operation to the reproducing operation. When trying to increase the data rate that enables chase playback,
It is necessary to make the time from the recording operation to the reproducing operation as short as possible. Therefore, when it is necessary to change the number of rotations when shifting from the recording operation to the reproducing operation as described above, the data rate at which the chase reproduction is possible becomes small. For example, in the case of encoding and recording a video / audio signal. Causes deterioration of image quality and sound quality.

As described above, the conventional method has many problems. The present invention solves the conventional problems, and an object of the present invention is to provide a simultaneous recording / reproducing apparatus in which the buffer amount on the recording side does not overflow.

It is another object of the present invention to provide a simultaneous recording / reproducing apparatus which does not increase the data transfer rate with the medium even in the case of chasing reproduction.

It is another object of the present invention to provide a simultaneous recording / reproducing apparatus which allows a user to notice that the reproducing position catches up with the recording position in the chase recording / reproducing.

It is another object of the present invention to provide a simultaneous recording / reproducing apparatus in which a reproduced image is not disturbed even when the reproducing position catches up with the recording position in the chase recording / reproducing.

Further, according to the present invention, it is possible to record and reproduce at a high data rate even when performing simultaneous recording / reproduction, chase reproduction, and simultaneous multi-channel reproduction using a recording medium for recording in the ZCLV system or CLV system. An object is to provide a recording / reproducing apparatus and a simultaneous multi-channel reproducing apparatus.

[0012]

A first simultaneous recording / reproducing apparatus of the present invention comprises a first buffer memory means for accumulating an input first code string, and a first code in the first buffer memory. Data input means for inputting a sequence, data recording means for recording the first code sequence read from the first buffer memory on the recording medium, and first code sequence recorded on the recording medium before a certain time. Data reproducing means for reading as the second code string, second buffer memory means for accumulating the second code string read by the data reproducing means, and data output for reading the second code string from the second buffer memory means And a system control means for monitoring the amount of data stored in the first buffer memory means. The system control means causes the data recording means and the data reproducing means to alternately perform the recording operation and the reproducing operation with respect to the recording medium in time.
When it is detected that the amount of data stored in the first buffer memory means exceeds the first predetermined amount, the reading of the second code string from the recording medium by the data reproducing means is temporarily stopped, and the recording medium by the data recording means. Control is performed so that the first code string is continuously written to. For example, in the above-mentioned simultaneous recording / reproducing apparatus, when it is detected that the amount of data stored in the first buffer memory means exceeds the first predetermined amount and becomes equal to or less than the second predetermined amount, the system control means again The data recording means and the data reproducing means are caused to perform the recording operation and the reproducing operation with respect to the recording medium alternately in time. Also,
For example, in the above-mentioned simultaneous recording / reproducing apparatus, when the system control means detects that the amount of data stored in the second buffer memory means becomes equal to or less than the third predetermined amount, the second buffer memory means by the data output means. The reading of the second code string from is temporarily stopped. Also, for example,
In the above simultaneous recording / reproducing apparatus, when the system control means further detects that the amount of data stored in the second buffer memory means becomes equal to or less than the third predetermined amount, the second buffer memory means by the data output means. When the second buffer memory means is controlled so as to temporarily stop the reading of the second code string from the second buffer memory means and becomes equal to or more than the fourth predetermined amount after the data accumulation amount of the second buffer memory means becomes equal to or less than the third predetermined amount, The output means controls so as to read the second code string from the second buffer memory means. In the above simultaneous recording / reproducing apparatus, for example, the data input means includes an encoding means for encoding the input first signal into a first code string, and the data output means is a second buffer memory. Decoding means for reading the second code string from the means, decoding it, and outputting it as a second signal are provided.

Further, a second simultaneous recording / reproducing apparatus of the present invention comprises an encoding means for encoding the input first signal into a first code string, and a first encoding means encoded by the encoding means. First buffer memory means for accumulating the code string, data recording means for recording the first code string read from the first buffer memory on a recording medium, and first data recorded on the recording medium before a certain time. Data reproducing means for reading out the code string as the second code string, second buffer memory means for accumulating the second code string read by the data reproducing means, and second code string from the second buffer memory means. And a system control means for setting a coding rate of the first signal in the coding means, and the data recording means and the data reproducing means are temporally arranged. When the system control means is set to the simultaneous recording / reproducing mode in which the recording operation and the reproducing operation are alternately performed on the recording medium and the first signal is recorded and the second signal is reproduced simultaneously, the first signal The coding rate of the coding means is made smaller than in the case where the normal recording mode in which only recording is performed is set. For example, the system control means sets the coding rate set in the coding means in the simultaneous recording / reproducing mode to 1/2 or less of the coding rate in the normal recording mode.

Further, a third simultaneous recording / reproducing apparatus of the present invention comprises an encoding means for encoding the input first signal into a first code string, and a first encoding means encoded by the encoding means. First buffer memory means for accumulating the code string, data recording means for recording the first code string read from the first buffer memory on the recording medium, and first data recorded on the recording medium before a certain time. Data reproducing means for reading out the code string as the second code string, second buffer memory means for accumulating the second code string read by the data reproducing means, and second code string from the second buffer memory means. And decoding means for reading and decoding and outputting as a second signal, and system control means for setting the coding rate of the first signal in the coding means. Here, the system control means causes the data recording means and the data reproducing means to alternately perform the recording operation and the reproducing operation with respect to the recording medium temporally. When the system control means is set to the simultaneous recording / reproducing mode in which the recording of the first signal and the reproduction of the second signal are simultaneously performed, the total value of the recording rate and the reproducing rate for a predetermined period is equal to or less than the predetermined bit rate. The encoding rate of the encoding means is set so that For example, the encoding by the encoding means is variable bit rate encoding.

Further, a third simultaneous recording / reproducing apparatus of the present invention comprises an encoding means for encoding the input first signal into a first code string, and a first encoding means encoded by the encoding means. First buffer memory means for accumulating the code string, data recording means for recording the first code string read from the first buffer memory on a recording medium, and first data recorded on the recording medium before a certain time. Data reproducing means for reading out the code string as the second code string, second buffer memory means for accumulating the second code string read by the data reproducing means, and second code string from the second buffer memory means. And a system control means for setting the coding rate of the first signal in the coding means. The system control means causes the data recording means and the data reproducing means to alternately perform the recording operation and the reproducing operation with respect to the recording medium in time. Here, the encoding means performs encoding at a variable bit rate, and reduces the encoding bit rate when the first buffer memory means is about to overflow.

Alternatively, the fourth simultaneous recording / reproducing apparatus of the present invention inputs the first code string to the first buffer memory means for accumulating the input first code string and the first buffer memory. Data input means, data recording means for recording the first code string read from the one buffer memory on the recording medium, and the first code string recorded on the recording medium before a certain time by the second code string. A data reproducing means for reading the data, a second buffer memory means for accumulating the second code string read by the data reproducing means, a data output means for reading the second code string from the second buffer memory means, And a system control means for monitoring the recording position of the code string on the recording medium and the reproducing position of the second code string from the recording medium. When the reproduction position catches up with the recording position within a predetermined time, the system control means switches the reading of the second code string from the recording medium by the data reproduction means to the normal reproduction operation or the stopped state or the paused state. In this simultaneous recording / reproducing apparatus, for example, even if the reproducing position catches up with the recording position within a predetermined time, the data reproducing means reads the second code string from the recording medium. In this simultaneous recording / reproducing apparatus, preferably, when the reproducing position catches up with the recording position within a predetermined time, the system control means notifies the display character generating means that the reproducing position catches up within the predetermined time of the previous recording position. , The display character generation means is
A character string indicating that the reproduction position has caught up within a predetermined time of the recording position is generated and displayed to the user. The display character generation means generates, for example, a symbol. Further, in this simultaneous recording / reproducing apparatus, the predetermined time is 0, for example.

In each of the above simultaneous recording / reproducing devices, for example, the first and second code strings are code strings obtained by coding a video or audio signal. Further, in each of the above simultaneous recording / reproducing devices, for example, the recording operation and the reproducing operation for the recording medium are performed by the same head. In each of the above simultaneous recording / reproducing devices, the recording medium is an optical disc, for example. Further, in each of the above-described simultaneous recording / reproducing devices, for example, the system control means updates the management data relating to the data recorded on the recording medium in the recording medium, for example, at regular intervals between recording and reproduction.
In each of the above simultaneous recording / reproducing devices, for example,
When the recording position of the data recording unit and the reproducing position of the data reproducing unit are separated from each other by a predetermined amount or more on the recording medium, the system control unit prohibits the temporally alternating recording operation and reproducing operation.

A fifth simultaneous recording / reproducing apparatus of the present invention is a simultaneous recording / reproducing apparatus which uses a recording medium having an optimum number of rotations which varies depending on a recording position, wherein a motor means for rotating the recording medium and a first input Buffer memory means for accumulating the code string, data input means for inputting the first code string to the first buffer memory, and the first code string read from the first buffer memory To a recording medium, data reproducing means for reading out the first code sequence recorded on the recording medium before a certain time as a second code sequence, and the first data sequence read by the data reproducing means. Second buffer memory means for storing a second code string, data output means for reading the second code string from the second buffer memory means, and the data recording means for recording A system control unit for monitoring the position of recording the first code string on the body and controlling the rotation speed of the motor unit, wherein the data recording unit and the data reproducing unit are alternately arranged in time. The recording / reproducing operation is performed for the system control means, and while the recording / reproducing operation is being performed, the system control unit maintains the rotation speed determined by the position where the first code string is recorded. For example, the first code string includes at least a code string obtained by coding a video signal or an audio signal. Further, for example, the system control unit causes the data recording unit to record from the outer peripheral zone toward the inner peripheral zone. Further, for example, the system control means causes the data recording means to perform recording so that the recording zone is always inside the reproduction zone. Further, for example, the system control means causes the data recording means to record from the outer side to the inner side in a unit within the zone. Further, for example, the rotation speed is within a predetermined margin with respect to the optimum rotation speed determined by the position where the first code string is recorded.

Further, a sixth simultaneous recording / reproducing apparatus of the present invention is a simultaneous recording / reproducing apparatus which uses a recording medium having an optimum number of revolutions at the time of recording which differs depending on a recording position, and motor means for rotating the recording medium, Encoding means for encoding the input first signal into a first code string; first buffer memory means for accumulating the first code string encoded by the encoding means; Data recording means for recording the first code string read from one buffer memory on a recording medium, and data for reading the first code string previously recorded on the recording medium for a certain time as a second code string Reproducing means, second buffer memory means for accumulating the second code string read by the data reproducing means, and reading and decoding the second code string from the second buffer memory means. And a system control means for monitoring the position where the data recording means records the first code string on the recording medium and controlling the rotation speed of the motor means. The data recording means and the data reproducing means perform a recording / reproducing operation to be performed on a recording medium alternately with respect to time, and the system control means records the first code string during the simultaneous recording / reproducing operation. Maintains the first speed determined by the position
The encoding means is obtained when the data at the recording position where the number of rotations on the recording medium is maximum is read out by using the second number of rotations which is optimum for the recording position where the number of rotations on the recording medium is minimum. Encode the first signal with a value less than or equal to the maximum data rate.

Preferably, the encoding means has an optimum rotation speed N when recording on the innermost circumference of the recording medium, an optimum rotation speed M when recording on the outermost circumference, and maximum recording on the recording medium. When the rate is R, the first signal is encoded at a data rate lower than the rate determined by R × M / N. Further, for example, the average coding rate within a predetermined time when the coding means codes the first signal is equal to or lower than the data rate.

In each of the above simultaneous recording / reproducing devices, for example, the first signal includes at least a video signal or an audio signal. Further, for example, the recording method of the recording medium is CL
V method or ZCLV method. Further, for example, the recording operation and the reproducing operation for the recording medium are performed by the same head. Further, for example, the recording medium is an optical disc. Further, preferably, the system control means causes the data recording means to record in a continuous empty area when performing the recording / reproducing operation which is alternately performed on the recording medium in time.

Also, the simultaneous multi-channel reproducing apparatus of the present invention is an simultaneous multi-channel reproducing apparatus which uses a recording medium in which at least two or more code strings are recorded because the optimum number of rotations during reproduction differs depending on the reproducing position. Therefore, there is provided a motor means for rotating the recording medium, a data reproducing means for performing a reproducing operation for alternately reading out the plurality of code strings from the recording medium temporally, and the data reproducing means for reproducing the code string from the recording medium. System control means for monitoring the position and maintaining the rotation speed of the motor means during the reproduction operation so that the rotation speed is such that the code string recorded on the inner circumference side of the recording medium is reproduced.

Further, for example, the system control means controls the rotation speed of the motor means during the reproduction operation so that the rotation speed is equal to or higher than the rotation speed for reproducing the code string recorded on the innermost circumference of the recording medium. maintain. Further, for example, the recording medium is an optical disc. Further, for example, the recording method of the recording medium is the CLV method or the ZCLV method. Also,
For example, the code string is a code string obtained by coding at least a video signal or an audio signal. Further, for example, the reproducing operation for the recording medium is performed by the same head.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same reference symbols represent the same or equivalent parts.

(First Embodiment) FIG. 1 shows a simultaneous recording / reproducing apparatus according to a first embodiment of the present invention. The simultaneous recording / reproducing apparatus includes a video / audio encoder 101, buffer memories 102 and 105, buffer amount counters 103 and 106, a video / audio decoder 104, a recording / reproducing signal processor 107, a system controller 108, an optical disk 109 and data. It consists of a selector 110.

Next, the normal operation of this simultaneous recording / reproducing apparatus will be described. First, the operation during recording will be described. The video / audio signal A is coded by the video / audio coder 101 to form a coded sequence. For example, if the video / audio encoder 101 is M
In the case of a PEG encoder, a video code string generated by MPEG encoding the video signal of the video audio signal A and an audio signal of the video audio signal A generated by MPEG encoding or AC-3 encoding. MPE with multiplexed voice code sequence
It becomes a G system code string and is output from the video / audio encoder 101. The code string output from the video / audio code string 101 is accumulated in the first buffer memory 102. The code string accumulated in the first buffer memory 102 is read by the data selector 110 and input to the recording / reproducing signal processor 107, subjected to ECC processing and modulation processing for recording on the optical disc 109, and then recorded. It is recorded on the optical disk 109 which is a medium. The first buffer amount counter 10
3 counts the amount of data input / output to / from the first buffer memory 102 to obtain the amount of data accumulated in the first buffer memory 102.

Next, the operation during reproduction will be described. The signal read from the optical disk 109 is subjected to binarization, demodulation, ECC processing, etc. in the recording / reproducing signal processor 107 to form a code string, and then input to the second buffer memory 105 via the data selector 110. To be done. The code string read from the second buffer memory 105 is the video / audio decoder 10
It is decoded at 4 and becomes the audiovisual signal B. The second buffer amount counter 106 counts the amount of data input / output to / from the second buffer memory 105,
Get the amount of data stored in 5.

The system controller 108 switches between recording and reproducing operations. The system controller 108
Whether the data is reproduced from the optical disk 109 or the data is recorded on the optical disk 109 is controlled depending on whether the reproducing operation or the recording operation is performed. Further, the data selector 110 is controlled so that data flows from the first buffer memory 102 to the recording / playback signal processor 107 during recording, and data flows from the recording / playback signal processor 107 to the buffer memory 105 during playback.

Next, the chase reproduction in the synchronous recording / reproducing apparatus shown in FIG. 1 will be described. FIG. 2 is a schematic diagram showing the concept of chasing playback, and shows the state of recording and playback when chasing and playing a certain program. First, recording of a certain program is started ((a) of FIG. 2). The shaded portion in (a) of FIG. 2 indicates that the data is recorded on the optical disc. Then, after recording for a certain time, the reproduction is started from the beginning of the program ((b) of FIG. 2).
However, recording will not stop even if playback is started, and recording will continue. Figure 2 shows the state after a certain time has passed from the start of playback.
(C) of. In FIG. 2C, the portion up to the reproduction position has already been reproduced. In the state as shown in FIG. 2C, the recording operation and the reproducing operation with respect to the optical disk 109 are performed simultaneously in time division.

The operation of the simultaneous recording / reproducing apparatus in the state of FIG. 2C will be described with reference to FIG. Figure 3
Access to optical disc 109, buffer memory 10
2 is a schematic diagram showing a situation of reading and writing data to and from Nos. 2 and 105, and a situation of temporal change of the video / audio signals A and B. FIG. The same symbol indicates the same data or the same data encoded or decoded. Further, FIG. 3 shows a case where the buffer and the disk simultaneously read and write the same amount of data. As shown in FIG. 3A, the optical disc 1
Access to 09 is performed by alternately reading and writing. In FIG. 3A, the shaded data represents the data reproduced from the optical disc 109,
Those not shaded indicate data recorded on the optical disc 109. For example, data a at time 301
After recording, the reproduction position of the data b is searched at time 302, and the data b is reproduced at time 303.

Next, the normal operation of the simultaneous recording / reproducing apparatus will be described with reference to FIG. FIG. 4 is a schematic diagram showing the arrangement of tracks on the optical disc 109 and recorded data. Now, it is assumed that the data to be recorded is recorded on consecutive tracks. Data a, c, e, g, i, k, m, o, q, s are recorded on the track 410, and data b, d, f, h, j, l, are recorded on the track 420.
Let n, p be recorded. In this case, data a is stored in area 4
After recording in area 01, the beginning of area 402 is searched, and area 4
The data b is reproduced from 02. After reproducing the data b, the head of the area 403 is searched and the data c is recorded in the area 403. The area here is, for example, a sector or an EC
C blocks, multiple ECC blocks, etc. can be considered.

Data i recorded on the optical disk 109,
k, m, etc. are the audiovisual signals A as shown in FIG.
The data input as is encoded by the video / audio encoder 101 and written in the first buffer memory 102. The timing is shown in FIG. Figure 3
The data written at the timing (d) is accumulated in the first buffer 102 for a certain time, and then the data is written at the first buffer memory 102 at the timing as shown in FIG.
Read out from and recorded on the optical disc 109 at the timing of FIG.

The data b, d, f, etc. reproduced from the optical disk 109 are read as shown in FIG. Then, as shown in FIG. 3C, the data is written in the second buffer memory 105. The data written in the second buffer memory 105 at the timing of (c) of FIG. 3 is accumulated in the second buffer 105 for a certain time, and then the data is written at the second buffer memory 105 at the timing of (e) of FIG.
Is read out to the video / audio decoder 104 and reproduced at the timing of (g) in FIG.

Next, in the operation situation as shown in FIG. 5, it takes longer than usual when searching by disk access,
The first buffer 102 is about to overflow. Specifically, at time 501, the optical disc 109
It takes a longer time than usual until the reproduction position of the data f is searched (time 502) after the data e has been written in. Further, after reading the data f from the optical disc 109 at time 503, it takes a longer time than usual until the search for the recording position of the data g ends (time 504). As will be explained below, in such a case, the recording operation is prioritized over the reproducing operation. That is, when the recording buffer is about to overflow, reproduction from the optical disc is stopped and recording is continuously performed.

The video / audio signal A is continuously input as shown in FIG. Therefore, the data writing to the first buffer memory 102 is also performed as usual as shown in FIG. However, as shown in FIG. 5B, when reading from the first buffer memory 102, the amount of data to be read becomes smaller because the search of the optical disk 109 takes longer than usual. As a result, the amount of data stored in the first buffer memory 102 becomes larger than usual as shown in (h) of FIG. When the data o is recorded in the first buffer 102 (time 5
In 13), the amount of data stored in the first buffer memory 102 exceeds the first predetermined amount. When the data storage amount of the first buffer memory 102 exceeds the first predetermined amount, the buffer amount counter 103 notifies the system controller 108 that the first predetermined amount has been exceeded. When the system controller 108 is notified by the first buffer amount counter 103 that the amount of data stored in the first buffer memory 102 exceeds the first predetermined amount, the system controller 108 temporarily stops the operation of reproducing data from the optical disc 109. Then, until the data storage amount in the first buffer memory 102 becomes equal to or smaller than the second predetermined amount, the data recording operation on the optical disc 109 is preferentially and continuously performed. In this example, the second predetermined amount is the same as the first predetermined amount. That is, time 50
After recording the data g in 4 (until time 505), the data storage amount of the first buffer memory 102 is inspected. At this point, as shown in (h) of FIG. 5, since the data storage amount of the first buffer memory 102 exceeds the second predetermined amount, the data i is continuously recorded on the optical disc 109. At the time when the recording of the data i is completed (time 506), the amount of data stored in the first buffer memory 102 is less than or equal to the second predetermined amount. Since writing to the first buffer memory 102 is performed here,
Then, the data k is written on the optical disc 109. Then, at the time when the recording of the data k on the optical disc 109 is completed (time 508), the data storage amount in the first buffer memory 102 is equal to or less than the second predetermined amount. The head position of the data h is searched for reading.

On the other hand, at time 506, the amount of data stored in the buffer memory 105 is zero. Normally, reading from the buffer memory 105 is performed at time 509, but the data storage amount of the buffer memory 105 is 0.
Therefore, the data is not read. Therefore, at time 510, the video / audio signal B to be output by the video / audio decoder 104 disappears. Therefore, the video / audio decoder 104 freezes and outputs the last frame of the video f from time 510 to time 512. At time 511, the data h is read from the buffer memory 105, and at time 512, the video / audio decoder 104 can prepare the video / audio signal B to be output. Therefore, the data h is output as the video / audio signal B.

As described above, the simultaneous recording / reproducing apparatus of this embodiment records the video / audio signal of a certain program on the recording medium,
While performing the recording operation, the video / audio signal which has already been recorded is reproduced after a certain time elapses, that is, chase reproduction is performed. During the simultaneous recording / playback or chasing playback, the buffer amount on the recording side and the playback side is monitored, and if the buffer amount on the recording side exceeds the first predetermined amount, the playback operation is paused and then continuously recorded. When the operation is performed and the buffer amount on the recording side becomes smaller than the second predetermined amount, the reproducing operation and the recording operation are alternately performed again. Due to such an operation, the seek operation between the reproducing operation and the recording operation takes time, and even if the buffer amount on the recording side becomes large, the recording of the data on the recording medium is guaranteed.

Although FIG. 4 shows a case where data that is temporally continuous is recorded in a continuous area,
The position where data is recorded does not have to be a continuous region.

Further, in the present embodiment, the case where the amount of data to be read from and written to the buffer memory and the optical disk at the same time has been shown, but this amount of data may be different each time reading and writing. Further, the amount of data to be accessed at one time for reading from and writing to the buffer memory may be different from that for reading from and writing to the optical disc. Further, the buffer memory or the optical disk may have different amounts of data accessed at one time when reading data and when writing data. Also, the first and second buffer memories 102,
105 may be configured using the same memory. For example, in the case of reproduction, it is used from the head side of the memory space, and in the case of recording, it is used from the last side.

In this embodiment, the case where the search is slow and the amount of data stored in the buffer memory exceeds the predetermined amount has been described. However, the simultaneous recording / reproducing apparatus of this embodiment can be used even when the data storage amount exceeds a predetermined amount due to other reasons. The amount of data stored in the buffer memory exceeds a predetermined amount, for example, when recording and reproducing at a variable bit rate, the total bit rate of the reproducing side bit rate and the recording side bit rate is higher than the predetermined bit rate. This is the case when it becomes higher. Further, such a situation also occurs when learning the recording / reproducing conditions, when there is a defective sector, and when writing to the file management area (TOC area). Recording learning is to learn and optimize parameters such as recording drive and focus for servo during recording. For example, focus learning must be performed when a drive temperature difference occurs over time. At the time of learning, the actual data recording / reproducing operation is stopped. Therefore, the recording buffer may overflow. The defective sector is detected when the sector address cannot be read. When a defective sector is detected, the sector is skipped and the next sector is recorded, the alternative sector is recorded, and the like. Therefore, the recording operation may be temporarily stopped and the recording buffer may overflow. The file management data is usually stored in the memory of the system controller, and the management data is recorded on the disc after all the data (for example, data for one program) has been recorded. However,
A system that manages file management data on a disk after recording a fixed amount of time or a fixed amount of data is also conceivable. In that case, since the recording / reproducing operation of the AV data is stopped while the file management data is being recorded, the recording buffer may overflow.

In this embodiment, the optical disk 10
9 is the same as the first predetermined amount with respect to the data storage amount of the first buffer memory 102 when the reproduction from 9 is temporarily stopped, and the second predetermined amount of the data storage amount of the first buffer memory 102 for restarting the reproduction is the same amount. Although a case has been described, these may have different values.

Further, in order to prevent the underflow of the reproduction buffer 105, the system controller 108 detects, for example, that the amount of data stored in the second buffer memory 105 has become equal to or less than the third predetermined amount, and the audiovisual signal is detected. The reading of the second code string from the second buffer memory 105 by the decoder 104 is temporarily stopped. System controller 1
08, when the data storage amount of the second buffer memory 105 exceeds the fourth predetermined amount after exceeding the third predetermined amount, the video / audio decoder 104 again causes the second buffer memory 105 to store the second data in the second buffer memory 105. Control to read the code string. The third predetermined amount and the fourth predetermined amount may be the same amount or different amounts.

(Second Embodiment) FIG. 6 shows a simultaneous recording / reproducing apparatus according to a second embodiment of the present invention. The simultaneous recording / reproducing apparatus includes a video / audio encoder 101, buffer memories 102 and 105, a video / audio decoder 104, a recording / reproducing signal processor 107, a system controller 601, and an optical disk 6.
09 and a data selector 110. However, this simultaneous recording / reproducing apparatus is different from the simultaneous recording / reproducing apparatus of the first embodiment in that it does not include a buffer memory counter. This simultaneous recording / reproducing apparatus can change the coding rate. For example, when recording / reproducing at a variable bit rate, when the total bit rate of the reproducing side bit rate and the recording side bit rate becomes higher than a predetermined bit rate, the data storage amount of the buffer memory becomes a predetermined amount. Exceed. Therefore, as will be described later, when the recording buffer is about to overflow, the system controller 601
Sets a low encoding bit rate during simultaneous recording and reproduction.

The basic operation of this simultaneous recording / reproducing apparatus is the same as the normal operation described in the first embodiment. The operation mode is set in the system controller 601. There are two operation modes, a normal recording mode and a simultaneous recording / reproducing mode (chase reproducing mode). The operation in the normal recording mode will be described with reference to FIG. FIG. 7 shows an optical disc 6
9 is a schematic diagram showing a situation of access to 09, reading / writing of data from / to the first buffer memory 102, and temporal change of the video / audio signal A. FIG. In the normal recording mode, only the video / audio signal A is recorded, and the reproducing operation from the optical disk 609 is not performed. The same symbols are used in FIG. 7 to indicate that the same data or the same data is encoded and decoded. Further, FIG. 7 shows a case where the buffer and the optical disk have the same amount of data read / written at one time. The data g, i, k, etc. recorded on the optical disk 609 are, as shown in (f) of FIG. It is written in the memory 102. The timing is shown in FIG. The data written at the timing of (d) of FIG. 7 is accumulated in the buffer 102 for a certain time, and then the data of FIG.
At the timing as shown in (b) of FIG.
2 and is recorded on the optical disc 609 at the timing of FIG.

Next, the operation in the chase reproduction mode will be described with reference to FIG. When set to the chase playback mode, as described below, both the recording and playback of the video / audio signal of the same time length within the same time as the recording of the video / audio signal of the time length in the normal recording mode are recorded. To enable the operation, the encoding rate at which the audiovisual signal encoder 101 encodes the audiovisual signal is set. Figure 8
Access to optical disc 609, first buffer memory 1
02/105 read / write data, video / audio signal A,
The situation of the temporal change of B is schematically shown. In FIG. 8, the same symbols as in FIG. 7 are used to indicate that the same data or the same data is encoded and decoded. Further, FIG. 8 shows a case where the buffer and the disk read and write the same amount of data at one time. When the chasing playback mode is set, the system controller 601 sets the video / audio encoder 101 so that the coding rate is lower than that in the normal recording mode. 8A to 8F have the same bit amount per time. As can be seen from the comparison with FIG. 7, the bit rate for encoding by the video / audio encoder 101 is low. Further, it is understood that while the video / audio signal of a certain time length is recorded in the normal recording mode, both the recording and the reproduction of the video / audio signal of the same time length are performed in the chase reproduction mode. For example, in the chase reproduction mode, the coding rate in the video / audio encoder 101 may be set to 1/2 or less as compared with the case of the normal recording mode.

As shown in FIG. 8A, the optical disk 6
Access to 09 is performed by alternately reading and writing. In FIG. 8A, the shaded data represents the data reproduced from the optical disc 609,
Those not shaded indicate data recorded on the optical disc 609. The data i, k, m, etc. recorded on the optical disc 609 are as shown in (f) of FIG.
What is input as the video / audio signal A is coded by the video / audio coder 101, and is converted into the first buffer memory 102.
Written in. The timing is shown in FIG. The data written at the timing of (d) of FIG. 8 is accumulated in the buffer 102 for a certain time, and then the first buffer memory 1 is stored at the timing of (b) of FIG.
02, and is recorded on the optical disc 609 at the timing of (a) of FIG.

Explaining the reading, the data b, d, f, etc. reproduced from the optical disk 609 are read as shown in FIG. And FIG. 8 (c)
It is written in the buffer memory 105 as shown in FIG. The data written in the buffer memory 105 at the timing of (c) of FIG. 8 is accumulated in the buffer 105 for a certain time, and then the data is written from the buffer memory 105 to the video / audio decoder at the timing of (e) of FIG. It is read out by 104 and reproduced at the timing of (g) of FIG.

By such an operation, when the chase reproduction mode is set, the chase reproduction can be performed without causing overflow or underflow of the buffer memory. Further, in the normal recording mode, since the coding rate can be set to a high coding rate according to the capability of the recording medium, it is possible to obtain high-quality and high-quality video / audio. In addition, since recording and reproduction are performed at the same time in the chase reproduction mode, simultaneous recording / reproduction and chase reproduction can be realized without increasing the transfer rate of the recording medium.

Further, in the above embodiment, the system controller 601 has set the video / audio encoder 101 so that the encoding rate is lower than that in the normal recording mode. However, in the modified example, the system controller 108 sets the coding rate to the same as usual in the chase playback mode. However, when determining that the recording buffer 102 is about to overflow in the chase playback mode, the system controller 108 forcibly lowers the encoding bit rate from the normal state by the encoder 101, and the recording buffer 102 is Suppress the possibility of overflow.

(Third Embodiment) Next, a simultaneous recording / reproducing apparatus according to a third embodiment of the present invention will be described.
This simultaneous recording / reproducing apparatus has the same configuration as the simultaneous recording / reproducing apparatus according to the second embodiment shown in FIG. However, the video / audio encoding device 101 performs encoding at a variable bit rate. Here, the coding rate in the chasing playback mode may be set so that the sum of the recording rate and the playback rate for a predetermined time is less than or equal to a predetermined bit rate.
That is, the system controller 108 sets the encoding rate of the encoder 101 so that the total value of the recording rate and the reproduction rate in the predetermined period is equal to or less than the predetermined bit rate.

(Fourth Embodiment) FIG. 9 shows a simultaneous recording / reproducing apparatus according to a fourth embodiment of the present invention. This simultaneous recording / reproducing apparatus includes a video / audio encoder 101, buffer memories 102 and 105, a video / audio decoder 104, a recording / reproducing signal processor 107, a system controller 901, an optical disk 909, and a data selector 110. This simultaneous recording / reproducing apparatus is different from the simultaneous recording / reproducing apparatus of the first embodiment in that it does not include a buffer memory counter. In this simultaneous recording / reproducing apparatus, when the user is performing follow-up reproduction by high-speed reproduction, as will be described later, if the recording buffer is about to overflow,
The system controller 901 returns to normal reproduction.

The basic operation of the simultaneous recording / reproducing apparatus is the same as the normal operation described in the first embodiment. FIG. 10 shows recording / reproducing on the optical disc 909 and the buffer memory 10 in the simultaneous recording / reproducing apparatus shown in FIG.
Writing and reading with respect to Nos. 2 and 105, and temporal changes of the audiovisual signals A and B are schematically shown. Figure 1
As shown in (a) of 0, reading and writing are alternately performed to access the optical disc 909. Figure 10
In (a), the shaded data indicates data reproduced from the optical disc 909, and the non-hatched data indicates recording on the optical disc 909.

In FIG. 10, up to time 1001, the simultaneous recording / reproducing apparatus normally performs simultaneous recording / reproducing (chase reproduction).
Take action. The data recorded on the optical disc 909 at time 1001 and the reproduction status are shown in FIG. FIG. 11 schematically shows the logical arrangement and reproduction status of the data recorded on the optical disc 909. As shown in FIG. 11A, at time 1001, up to the data o is recorded on the optical disc 909, and the already recorded data is reproduced up to the data c.

Here, at time 1001, the system controller 90
It is assumed that reproduction control for performing high-speed reproduction is input for 1. By this reproduction control, the system controller 901 reads out data for high-speed reproduction from the optical disc 909. That is, after reproducing the data g, the data i
Play data k without playing. In addition, the video / audio decoder 104 is notified that high-speed reproduction data is input. The recording and reproducing conditions for the optical disc 909 at time 1002 are shown in FIG. After that, the system controller 901 performs reproduction while thinning out the data recorded on the optical disk 909.

Now, the optical disc 90 at time 1003
The recording and reproducing conditions for No. 9 are shown in FIG.
At time 1003, reproduction up to the data t has been performed on the optical disc 909. Therefore, the data to be reproduced next is the data recorded next to the data u,
At time 1003, the data next to the data u has not been recorded yet. Therefore, the system controller 901 ends the high-speed reproduction operation, shifts to the normal reproduction operation, and reproduces the data u. The recording / reproducing situation for the optical disc 909 at time 1004 is shown in FIG. After that, the system controller 901 performs normal reproduction from the optical disc 906. FIG. 11 (e) shows a recording / reproducing situation with respect to the optical disc 909 at time 1005.

Further, the simultaneous recording / reproducing apparatus reproduces from the optical disk 909 without reproducing in the EE system even if the reproducing position catches up with the recording position. To perform playback on the EE system, refer to FIG.
In 902, reproduction may be performed using the system of 902. However, for example, when the system controller 901 is subjected to reproduction control for performing reverse reproduction after the reproduction position catches up with the recording position and shifts to the normal reproduction operation, if reproduction is performed in the EE system, Since the reproduction from the optical disc 909 has to be performed, the operation becomes complicated. Even if the reproduction position catches up with the recording position, if reproduction is performed from the optical disc 909 without performing reproduction by the EE system, reproduction control for performing reverse reproduction after the reproduction position catches up with the recording position and shifts to the normal reproduction operation. Even when the operation is performed on the system controller 901, the reverse playback operation can be smoothly performed.

As described above, the simultaneous recording / reproducing apparatus of this embodiment performs high-speed reproduction or the like during simultaneous recording / reproducing or chasing reproduction, and when the reproducing position catches up with the recording position,
The high-speed reproduction operation is shifted to the normal reproduction operation so that the reproduction position does not overtake the recording position. Since the reproduction position does not overtake the recording position by such an operation, it is possible to prevent meaningless data from being reproduced and the video and audio from being disturbed.

Further, the simultaneous recording / reproducing apparatus of the present embodiment reproduces from the optical disc without reproducing in the EE system even if the reproducing position catches up with the recording position. By such an operation, even when the reproduction position catches up with the recording position and the normal reproduction operation is performed, and then, for example, the reproduction control for performing the reverse reproduction is performed, the reverse reproduction operation can be smoothly performed.

In the present embodiment, the buffer memory,
The case where the amount of data read and written to the disk at one time is the same is shown, but this amount of data may be different each time the data is read and written. Also, the amount of data to be accessed at one time for reading from and writing to the buffer memory may be different from that for reading from and writing to the disk. Further, the buffer memory or the optical disk may have different amounts of data accessed at one time when reading data and when writing data.

In the present embodiment, the method of skipping the data one unit at a time has been described as the data thinning method at the time of high speed reproduction, but this may be another thinning method.

In the present embodiment, an example has been described in which, when high-speed reproduction or the like is performed during the follow-up reproduction, the high-speed reproduction operation is canceled when the reproduction position catches up with the recording position, and the normal reproduction operation is started. However, when the reproduction position catches up within a predetermined time from the recording position, the high speed reproduction operation may be automatically canceled and the normal reproduction operation may be started.

Further, in the present embodiment, the case where the reproduction position catches up with the recording position by performing the high speed reproduction during the chasing reproduction has been described. The recording / reproducing apparatus of the embodiment can be used. For example, the reproduction position may catch up with the recording position because the recording operation is temporarily stopped or stopped. In such a case, when the reproduction position catches up with the recording position, the reproduction operation may shift to the stopped state or the paused state.

(Fifth Embodiment) FIG. 12 shows a simultaneous recording / reproducing apparatus according to a fifth embodiment of the present invention. This simultaneous recording / reproducing apparatus includes a video / audio encoder 101, buffer memories 102 and 105, a video / audio decoder 104, a recording / reproducing signal processor 107, a system controller 1201, an optical disk 909, a data selector 110, and a display character generator. 1202 and a video signal superimposing unit 1203. This simultaneous recording / playback device performs high-speed playback, etc. during chasing playback,
When the reproduction position catches up with the recording position, when the high-speed reproduction operation is canceled and the normal reproduction operation is started, the fact that the normal reproduction operation is started is displayed on the screen. By performing such an operation, it is possible to inform the user that the high-speed operation has automatically changed to the normal operation. The user can know why the high-speed operation has changed to the normal operation, and can provide a user-friendly user interface.

The operation relating to the chase reproduction of this simultaneous recording / reproducing apparatus is the same as the operation described in the third embodiment. That is, the high-speed reproduction is performed during the chasing reproduction, and when the reproduction position catches up with the recording position, the high-speed reproduction operation is canceled and the normal operation is performed.

The operation of this simultaneous recording / reproducing apparatus when the reproduction position catches up with the recording position will be described.
When the system controller 1201 detects that the reproduction position has caught up with the recording position at time 1003 in FIG. 10,
The system controller 1201 notifies the display character generator 1202 that the reproduction position has reached the recording position.
Upon receiving the notification from the system controller 1201, the display character generator 1202 generates character data indicating that the reproduction position has caught up with the recording position, and the video signal superimposing unit 1202.
Output to 3. The video signal superimposing unit 1203 superimposes the video / audio signal output from the video / audio decoding unit 104 and the character data output from the display character generator 1202, and outputs it as the video / audio signal B. As an example of the display, there is a display example such as 1301 in FIG.

In the embodiment of the present invention, the case where the display character generator 1202 generates a character has been described, but this may be a symbol, an icon or the like.

In each of the above-mentioned embodiments, the case where the optical disk is used as the recording medium has been described, but this may be another recording medium such as a magnetic disk.

Further, in each of the above-described embodiments, the case where the amount of data to be read from and written to the buffer memory and the disk at the same time is shown is the same, but this amount of data may be different each time reading and writing. Also, the amount of data to be accessed at one time for reading from and writing to the buffer memory may be different from that for reading from and writing to the disk. Further, the buffer memory or the optical disk may have different amounts of data accessed at one time when reading data and when writing data.

Preferably, in each of the above-described embodiments, the recorded data is guaranteed even if a power failure occurs during chasing playback. In the normal operation, management information (address information etc.) of recorded data is accumulated in the memory of the system controller, and after recording all data (for example, one program's worth of data), the management data is recorded on the disc.
The recording / reproduction is a sequence of data recording → data reproduction → data recording → data reproduction. However, if a power failure occurs during operation and the management data is lost, the audio / video information cannot be reproduced even if it is recorded on the disc.
Therefore, by recording the management data on the disk at regular intervals, it is possible to prevent the management data from being lost due to a power failure or the like. In this case, record data a certain number of times →
After repeating the data reproduction sequence, the management data is written in the file management area. Since management data is updated when video / audio information is recorded, it is desirable to record the management data after recording the video / audio data.

Further, in each of the above-mentioned embodiments, a limit may be set on the chase reproduction. For example, when the recording zone and the reproducing zone are too far apart, the seek time becomes longer accordingly, so that the recording buffer 102 easily overflows and the reproducing buffer 105 easily underflows. Therefore, the system controller 10
No. 8 prohibits chasing playback when the recording zone and the playback zone are too far apart. Even if the user inputs the chase play, the acceptance is rejected. In particular,
For example, the zone range in which the chasing playback zone is performed is limited. For example, if it is determined that the recording zone and the playback zone are apart from each other by a certain threshold value (2 zones) or more between the zones where the seek time is a predetermined time or more,
Prohibit chasing playback.

(Sixth Embodiment) FIG. 14 shows a simultaneous recording / reproducing apparatus according to a sixth embodiment of the present invention. This simultaneous recording / reproducing apparatus includes a video / audio encoder 101 and a buffer memory 1.
02, 105, video / audio decoder 104, recording / reproducing signal processor 107, system controller 1408, optical disk 1
09, a data selector 110, an optical head 1411, and a motor 1412. In this simultaneous recording / reproducing apparatus, reproduction is performed from other zones while maintaining the rotation speed of the recording zone.

Regarding the simultaneous recording / reproducing apparatus of FIG. 14, the operation at the time of recording will be described first. The video / audio signal A is coded by the video / audio coder 101 to form a coded sequence. For example, when the video / audio encoder 101 is an MPEG encoder, the video code string generated by MPEG-encoding the video signal of the video / audio signal A and the audio signal of the video / audio signal A are MPEG-encoded. The audio code sequence generated by AC-3 encoding is multiplexed to form an MPEG system code sequence, which is output from the video / audio encoder 101. The code string output from the video / audio code string 101 is the buffer memory 1
Accumulated in 02. The code string accumulated in the buffer memory 102 is read out by the data selector 110, input to the recording / reproducing signal processor 107, and subjected to ECC processing and modulation processing for recording on the optical disc 109.
It is recorded on the optical disc 109 via the optical head 1411.

Next, the operation during reproduction will be described. The signal read from the optical disc 109 via the optical head 1411 is binarized and demodulated by the recording / reproducing signal processor 107.
After being subjected to ECC processing and the like to form a code string, it is input to the buffer memory 105 via the data selector 110. The code string read from the buffer memory 105 is decoded by the audio / video decoder 104 to become the audio / video signal B.

The system controller 1408 switches between recording and reproducing operations. Depending on whether the system controller performs a recording operation or a reproducing operation, the optical disk 10
9 to reproduce data, or the optical disc 109
Controls whether data is recorded in. The system controller 1408 controls the data selector 110 so that the recording / recording / reproducing signal processor 10 is transferred from the buffer memory 102 during recording.
7 is controlled so that data flows to the buffer memory 105 from the recording / reproducing signal processor 107 during reproduction.

The chase reproduction in this synchronous recording / reproducing apparatus will be described. The recording / reproducing operation in the chasing reproduction state shown in FIG. 2C is shown in FIG. This recording / reproducing operation will be described with reference to FIG. Figure 15 shows
FIG. 3 is a schematic diagram showing the arrangement of zones, tracks, and recorded data on the optical disc 109. Spiral lines indicate tracks. Now optical disc 1
At 09, it is assumed that the data is recorded by the zone CLV (ZCLV) method. Also, it is assumed that the data to be recorded is recorded on continuous tracks. Further, it is assumed that the data is recorded from the inner circumference toward the outer circumference. Here, a case where recording / reproduction is performed in the zones 1501 and 1502 will be described.

First, recording is performed in the zone 1501.
The case of performing reproduction from 502 will be described. Now, in the areas 1520, 1521, 1522, and 1523, the data b,
It is assumed that d, f, and h are recorded. Further, it is assumed that the data a is recorded in the area 1510. In this case, after the data a is recorded in the area 1510, the head of the area 1520 is searched and the data b is reproduced from the area 1520. After that, the head of the area 1511 is searched and the data c is recorded in the area 1511. Then search the beginning of the area 1521,
The data d is reproduced from the area 1521. During this recording and reproducing operation, the number of rotations of the optical disk 109 is the zone 150.
The number of revolutions when recording data in 1 is kept constant. Therefore, even when reproducing data from the zone 1502,
Reproduction is performed at the number of rotations when data is recorded in the zone 1501. This rotation control is performed by determining which zone the system controller 1408 is currently performing the recording operation, and controlling the motor 1412 so that the determined rotation speed is achieved. In the ZCLV method, the inner peripheral side has a higher rotational speed, and in this case, the reproduction from the zone 1502 is performed at a rotational speed slower than usual. However, since the margin for reproducing the data from the disc is much larger than that for recording, it is possible to correctly reproduce even if the data is reproduced from the zone 1502 while keeping the slow rotation speed suitable for recording in the zone 1501. .

Next, recording is performed in zone 1502 and zone 1
The case of performing reproduction from 501 will be described. Now, data is stored in areas 1510, 1511, 1512, and 1513,
It is assumed that b, d, f, and h are recorded. Further, it is assumed that the data a is recorded in the area 1520. in this case,
After recording the data a in the area 1520, the head of the area 1510 is searched and the data b is reproduced from the area 1510.
After that, the head of the area 1521 is searched and the data c is recorded in the area 1521. After that, the beginning of the area 1511 is searched and the data d is reproduced from the area 1511. During this recording and reproducing operation, the number of rotations of the optical disk 109 is in the zone 15
The number of revolutions when recording data in 02 is fixed. Therefore, even when the data is reproduced from the zone 1501, it is reproduced at the number of rotations when recording the data in the zone 1502. This rotation control is performed by determining which zone the system controller 1408 is currently performing the recording operation, and controlling the motor 1412 so that the determined rotation speed is achieved. In the ZCLV method, the number of rotations is higher on the inner circumference, so in this case the zone 1501
The reproduction from will be performed at a faster rotation speed than usual. However, since the margin for reproducing data from the disc is much larger than that for recording, even if the data is reproduced from the zone 1501 with a high rotation speed suitable for recording in the zone 1502, the reproduction can be correctly performed. .

As described above, this simultaneous recording / reproducing apparatus is
The video / audio signal of a certain program is recorded on a recording medium, and while the recording operation is being performed, the operation of reproducing the video / audio signal recorded up to that point, that is, chasing reproduction. During the simultaneous recording / reproduction, the rotation speed of the optical disk is kept constant at a rotation speed suitable for the zone in which the recording operation is performed, and the reproduction is performed at the same rotation speed even during the reproduction. Since the margin for reproducing data from the disc is much larger than that for recording, it is possible to correctly reproduce even if data is reproduced from different zones while keeping the rotation speed suitable for the recorded zone.

By performing such an operation, when the recording operation is changed to the reproduction operation or the reproduction operation is changed to the recording operation in the simultaneous recording / reproduction, the rotation speed is changed between the recording position and the reproducing position even in the case of the ZCLV disc. There is no need to do it. Therefore, the time between the recording operation and the reproducing operation can be shortened and the operation efficiency can be improved.
Due to this improvement in operation efficiency, the video / audio signal can be encoded at a high encoding rate for recording and reproduction.

In the present embodiment, the case where the optical disk 109 is recorded by the ZCLV method has been described, but other methods may be used as long as the rotation speed differs depending on the recording position such as the CLV method.

Further, although the case where the track is spiral as described in FIG. 15 has been described in the present embodiment, the track may not be spiral.

Although FIG. 15 in the present embodiment shows the case where temporally continuous data is recorded in a continuous area, the data recording position may not be a continuous area.

Further, in the present embodiment, the case where the amount of data read / written to / from the buffer memory or the disk at the same time is shown, but this amount of data may be different each time reading / writing is performed. Also, the amount of data to be accessed at one time for reading from and writing to the buffer memory may be different from that for reading from and writing to the disk. Further, the buffer memory or the optical disk may have different amounts of data accessed at one time when reading data and when writing data.

Further, although the case where the video / audio encoder 101 performs encoding at a fixed bit rate has been described in the present embodiment, this may be variable bit rate encoding.

In the ZCLV system, the rotation speed is faster in the inner peripheral zone. For this reason, when performing playback from the recording zone in chasing playback, if the playback zone is on the inner circumference side, the recording rate of that zone may exceed the playback rate,
In such a case, the reproduced image will be interrupted halfway. Therefore, in order to avoid such a situation, preferably, the zone selection method for the simultaneous recording / reproducing described above is limited as follows. That is, recording is performed from the outer zone to the inner zone. When a certain zone is reproduced by the chasing reproduction, the reproduction is performed at a higher rotation speed than that when the zone is recorded. As a result, when the zone that is the follow-up playback is played back, the playback is performed at a higher rotation speed than when the zone was recorded, and the playback image is not interrupted halfway. In another method, even if the recording area is not continuous, recording is started from the outer peripheral zone as much as possible and sequentially recorded in the inner peripheral zone. That is, the recording zone must be inside the reproduction zone. This has the same effect. In yet another method, recording is performed from the inner circumference to the outer circumference according to a spiral in the zone. That is, in the zone, recording is performed from the outside to the inside. In addition, recording is done in a certain unit. The “certain unit” is, for example, a plurality of heads, a plurality of ECC blocks, or a data amount corresponding to a video / audio signal for a predetermined time (for example, recording / playback switching time in chasing playback). This allows the seek time to be as short as possible.

(Seventh Embodiment) Next, a simultaneous recording / reproducing apparatus according to a sixth embodiment of the present invention will be described with reference to FIGS. 14 and 16. The components of this simultaneous recording / reproducing apparatus are the same as those in FIG. 14, but the operation of the system controller 1408 is different. The basic operation of the simultaneous recording / reproducing apparatus of this embodiment is
It is similar to the seventh embodiment shown in FIG. That is, when performing simultaneous recording / reproduction (chase reproduction), the reproduction operation is also performed while maintaining the rotation speed determined by the position on the recording medium on which the recording operation is performed. Here, in this simultaneous recording / reproducing apparatus, at a rotation speed most suitable for the recording position where the rotation speed on the recording medium is the minimum, the rate is equal to or lower than the rate when reading the data of the zone where the rotation speed on the recording medium is the maximum. The encoding bit rate is controlled so that The points different from the simultaneous recording / reproducing apparatus of the sixth embodiment will be described below.

FIG. 16 shows the zone structure of the optical disk 109. Here, the case where the optical disk 109 is recorded by the ZCLV method will be described. As shown in FIG. 16, the optical disc 109 is divided into five zones 1601 to 1605 from the outer circumference toward the inner circumference. When recording is performed on the optical disc 109, the rotation speed changes for each zone. This speed is
This is realized by the system controller 1408 controlling the motor 1412.

Now, it is assumed that the rotation speed of the outermost zone 1601 is M and the rotation speed of the innermost zone 1605 is N. The maximum recording rate of the optical disk 109 is R. In this case, the system controller 1408 determines that the video / audio encoder 101 has the video / audio signal A.
Is determined so that the coding rate at the time of coding is smaller than the value determined by the equation (1).
01 performs coding at the coding rate determined by the system controller 1408.

[0089]

[Equation 1]

Here, when the video / audio encoder 101 performs encoding at the encoding rate given from the system controller 1408, it may be fixed bit rate encoding, or the average bit rate of a certain interval is Variable bit rate coding that satisfies a given coding rate may be used.

As described above, the simultaneous recording / reproducing apparatus of the present embodiment records the video / audio signal of a certain program in the recording medium, and performs the recording operation while reproducing the video / audio signal recorded up to that point. In other words, chase and play. During the simultaneous recording / reproduction, the rotation speed of the optical disk is kept constant at a rotation speed suitable for the zone in which the recording operation is performed, and the reproduction is performed at the same rotation speed even during the reproduction. When performing this simultaneous recording / playback, obtain the bit rate for encoding the video / audio signal when the data of the zone with the maximum rotation speed is read out using the optimum rotation speed for the zone with the minimum rotation speed. It should be less than the maximum data rate.

By performing such an operation, when the control is performed in the state where the rotation speed is the minimum, that is, when the recording operation is performed in the outermost zone, the reproducing operation must be performed in the innermost zone. Even if it does not happen, the recorded data rate is a value that can guarantee the data rate even if the data in the innermost circumferential zone is read when the number of revolutions is minimum, so it can be obtained by decoding. It is possible to guarantee the real-time property of the video / audio signal.

In the present embodiment, the case where the optical disk 109 is recorded by the ZCLV method has been described, but another method may be used as long as the rotation speed differs depending on the recording position such as the CLV method.

In this embodiment, the case where the number of zones is 5 has been described as shown in FIG. 16, but this may be a different value.

In the present embodiment, the buffer memory,
The case where the amount of data read and written to the disk at one time is the same is shown, but this amount of data may be different each time the data is read and written. Also, the amount of data to be accessed at one time for reading from and writing to the buffer memory may be different from that for reading from and writing to the disk. Further, the buffer memory or the optical disk may have different amounts of data accessed at one time when reading data and when writing data.

Although the chasing reproduction has been described in the sixth and seventh embodiments, it is desirable to shorten the seek time as much as possible in order to prevent buffer overflow and underflow during chasing reproduction.
Therefore, at the time of recording, prior to recording, a continuous free area as large as possible is found and data is continuously recorded in the area. As a result, the data is recorded in the close zone, and the seek time can be reduced.

In the sixth and seventh embodiments, the number of revolutions of the optical disk is kept constant at the number of revolutions suitable for the zone in which the recording operation is performed, and the number of revolutions is also maintained at the time of reproduction. The case has been described where the chase reproduction is performed. Here, there is a slight margin in the recording operation with respect to the number of rotations. Therefore, the rotation speed may be determined within this margin. For example, if the recording position is on the outer peripheral side of the reproducing position, the reproducing operation will be performed at a rotational speed slower than the original rotational speed, but the rotational speed is within the margin of the rotational speed determined by the recording position. By maximizing the speed, the number of rotations of the reproducing operation can be slightly increased. As a result, restrictions on the coding rate and the like during chasing playback are relaxed.

(Embodiment 8) FIG. 17 shows a multi-channel simultaneous reproducing apparatus according to an eighth embodiment of the present invention. This multi-channel simultaneous reproducing apparatus, as shown in FIG. 17, has a reproducing signal processor 1701, a data selector 1702, buffer memories 1703 and 1704, and a video / audio encoder 170.
5, 1706, system controller 1707, optical disk 1
708 and an optical head 1709. In this multi-channel simultaneous reproduction device, during multi-channel simultaneous reproduction, reproduction is also performed from the outer peripheral zone in accordance with the number of rotations read from the inner peripheral zone.

It is assumed that two code strings as shown in FIG. 20 are recorded on the optical disc 1708. FIG. 18 shows a logical arrangement of two code strings. FIG. 20 (a) shows the video / audio signal C and FIG. 20 (b) shows the video / audio signal D.

FIG. 19 shows the zone structure of the optical disc 1708. It is assumed that the optical disc 1708 is recorded by the ZCLV method. Here, it is assumed that the code string of the video / audio signal C is recorded in the zone 1901 and the code string of the video / audio signal D is recorded in the zone 1902.

It is considered that the code strings of the video and audio signals C and D are read from the optical disc 1708 and reproduced simultaneously. FIG. 18 is a schematic diagram showing temporal changes in the access status to the optical disk 1708, the access status to the buffer memories 1703 and 1704, and the playback status of the video / audio signals C and D at that time. The use of the same symbol in FIG. 18 indicates that the same data or the same data is decoded.

The operation of the simultaneous multi-channel reproducing apparatus will be described with reference to FIGS. Optical disk 170
A signal read from the optical head 1709 from the
The reproduction signal processor 1701 performs binarization, demodulation, ECC processing, etc. to form a code string, and then a data selector 1702.
Via the buffer memory 1703 or 1704. The code string read from the buffer memory 1703 or 1704 is a video / audio decoder 1705 or 1
The video / audio signal C or D is decoded at 706.

Here, the buffer memories 1703 and 1704 are
The data selector 1702 switches to which of the two, the code string read from the optical disk 1708 is written. The system controller 1707 reads the code string of the video / audio signal C from the optical disk 1708 or the code string of the video / audio signal D from the optical disk 1708, and the code string read from the optical disk 1708 is stored in the buffer memories 1703 and 1704. Controls which to write to. Here, the buffer memory 170
It is assumed that the code string of the video / audio signal C is written in 3, and the code string of the video / audio signal D is written in the buffer memory 1704.

As shown in FIG. 18A, the optical disc 1
To access 708, the code string of the video / audio signal C and the code string of the video / audio signal D are alternately read.
In FIG. 18A, the hatched line indicates the reading of the code string of the video / audio signal D, and the non-hatched line indicates the reading of the code string of the video / audio signal C. For example, in period 701, data a (video / audio signal C
After reproducing the part of the code string of (1), the reproduction position of the data b is searched (period 702), and the data b (a part of the code string of the video / audio signal D) is reproduced in the period 703.

The data a, c, e, etc. reproduced from the optical disk 1708 are written in the buffer memory 1703 as shown in FIG. The data b, d, f, etc. are written in the buffer memory 1704 as shown in FIG. The data written in the buffer memories 1703 and 1704 at the timings of (b) and (c) of FIG. 3 are accumulated in the buffers 1703 and 1704 for a certain time, and then, as shown in (d) and (e) of FIG. The video / audio decoders 1705 and 1706 are read from the buffer memories 1703 and 1704 at various timings and reproduced at the timings (f) and (g) in FIG. 18, respectively.

Here, the data a, c, e, etc. are in the zone 190.
1 and the data b, d, f, etc. are recorded in zone 19
It is recorded in 02. Therefore, the reproduction operation described above is performed for data reproduction from zone 1901, zone 1
The operations of searching and moving from 901 to zone 1902, reproducing data from zone 1902, and searching and moving from zone 1902 to zone 1901 are repeated. During this reproducing operation, the rotation speed of the optical disk 1708 is kept constant at the rotation speed when reproducing data from the zone 1902. Therefore, even when the data is reproduced from the zone 1901, it is reproduced at the number of rotations when reproducing the data from the zone 1902. This rotation control is performed by the system controller 1707 determining from the number of revolutions for reproducing the innermost zone of the currently reproduced zone group, and controlling the motor 1710 to reach the determined number of revolutions. . In the ZCLV method, the rotation speed is higher in the inner circumference, and in this case, the reproduction from the zone 1901 is performed at a higher rotation speed than usual. However, playing data from a disc has a very large margin,
Even if the data is reproduced from the zone 1901 with the high rotation speed suitable for the reproduction from the zone 1902, the reproduction can be correctly performed.

As described above, this simultaneous multi-channel reproducing apparatus reproduces the code strings of a plurality of video / audio signals simultaneously in a time division manner from the recording medium in which the code strings obtained by coding a plurality of video / audio signals are recorded. To do. During the simultaneous multi-channel reproduction, the rotation speed of the optical disk is kept constant at a rotation speed suitable for the inner peripheral side zone, and even when data is reproduced from the outer peripheral side zone, reproduction is performed at the same rotational speed. Since the margin for reproducing the data from the disc is very large, even if the data is reproduced from the outer zone while keeping the high rotation speed suitable for the inner zone, the data can be correctly reproduced.

By performing such an operation, when the reproduction operation of one channel is changed to the reproduction operation of another channel in the simultaneous multi-channel reproduction, the rotation speed is changed at the reproduction position even for the ZCLV disc. There is no need. Therefore, the time required to move the zone can be shortened and the operation efficiency can be improved. Due to this improvement in operation efficiency, it is possible to reproduce a multi-channel code string of a video / audio signal having a high coding rate. Moreover, since the number of revolutions of the inner circumferential side zone is matched, the data rate when reproducing the data recorded in the inner circumferential side zone can be guaranteed.

In the present embodiment, the case where the optical disk 109 is recorded by the ZCLV method has been described, but other methods may be used as long as the rotation speed differs depending on the recording position such as the CLV method.

Further, in the present embodiment, the case where the track is spiral as shown in FIG. 19 has been described.
However, the track does not have to be spiral.

Note that FIG. 15 in the present embodiment shows the case where temporally continuous data are recorded in the same zone. However, the data recording positions do not have to be in the same zone.

Further, in the present embodiment, the case where two-channel data are reproduced simultaneously has been described. However, the number of channels may be three or more.

Further, in the present embodiment, the case has been described in which, when data of two channels are simultaneously reproduced, the rotation speed is controlled in accordance with the zone on the inner peripheral side of the reproduced channels. However, the reproduction may be performed at the number of revolutions at which the innermost zone is always reproduced or at the number of revolutions or more.
For example, when reproducing the optical disk 1708, it is sufficient to reproduce the zone 1903 at the number of rotations at which it is reproduced, or at the number of rotations or more. As a result, it is possible to guarantee the data rate when reproducing data regardless of which zone the data is reproduced.

In each of the above simultaneous recording / reproducing devices, the recording operation and the reproducing operation for the recording medium are preferably performed by one head (the same head). Further, in the above-mentioned simultaneous multi-channel reproducing apparatus, reproduction on a plurality of channels is preferably performed by one head (same head). This simplifies the structure of the device.

[0115]

According to the simultaneous recording / reproducing apparatus of the present invention, the video / audio signal of a certain program is recorded on the recording medium, and the video / audio signal which has already been recorded after a lapse of a certain time while performing the recording operation is reproduced, that is, chased. Play. During the simultaneous recording / playback or chasing playback, the buffer amount on the recording side and the playback side is monitored, and if the buffer amount on the recording side exceeds a predetermined amount, the playback operation is paused and then the recording operation is performed continuously. Then, when the buffer amount on the recording side becomes smaller than the predetermined amount, the reproducing operation and the recording operation are alternately performed again. By such an operation, even if the buffer amount on the recording side becomes large, for example, when the seek operation between the reproducing operation and the recording operation takes too long, the recording of the data on the recording medium is guaranteed.

Further, the simultaneous recording / reproducing apparatus of the present invention has two modes, that is, the normal recording mode and the chase reproducing mode, and when set in the chase reproducing mode, the video / audio signal of the time length which is the normal recording mode is recorded. The encoding rate at which the audiovisual signal encoding device encodes the audiovisual signal so that both the recording and reproducing operations of the audiovisual signal having the same time length can be performed within the same time. To set. By such an operation, when the chasing reproduction mode is set, the chasing reproduction can be performed without causing overflow or underflow of the buffer memory. Further, in the normal recording mode, the coding rate can be set to a high coding rate according to the capability of the recording medium, so that high-quality and high-quality video / audio can be obtained in the normal recording mode. In addition, since recording and reproduction are performed at the same time in the chase reproduction mode, simultaneous recording / reproduction and chase reproduction can be realized without increasing the transfer rate of the recording medium.

Further, in the simultaneous recording / reproducing apparatus of the present invention, during simultaneous recording / reproducing or chase reproducing, when the reproducing position catches up with the recording position by performing high speed reproducing or the like, the high speed reproducing operation is canceled to shift to the normal reproducing operation. However, the playback position does not overtake the recording position. Since the reproduction position does not overtake the recording position by such an operation, it is possible to prevent meaningless data from being reproduced and the video and audio from being disturbed.

Further, the simultaneous recording / reproducing apparatus of the present invention performs the normal reproduction when the high-speed reproduction is canceled during the chase reproduction and the reproduction position catches up with the recording position, and the high-speed reproduction operation is canceled and the normal reproduction operation is started. The fact that the operation is started is displayed on the screen. By performing such an operation, it is possible to inform the user that the high-speed operation is automatically changed to the normal operation, the user can know why the high-speed operation is changed to the normal operation, and the user-friendly operation can be performed. A user interface can be provided.

Further, the simultaneous recording / reproducing apparatus of the present invention records the video / audio signal of a certain program on the recording medium, and performs the recording operation while reproducing the video / audio signal recorded up to that point, that is, the chase. Play. During the simultaneous recording / reproduction, the rotation speed of the optical disk is kept constant at a rotation speed suitable for the zone in which the recording operation is performed, and the reproduction is performed at the same rotation speed even during the reproduction. Since the margin for reproducing data from the disc is much larger than that for recording, even if the data is reproduced from different zones while keeping the rotation speed suitable for the recorded zone, it can be reproduced correctly. By performing such an operation, when the recording operation is changed to the reproduction operation or the reproduction operation is changed to the recording operation in the simultaneous recording / reproduction, C
Even with an LV or ZCLV disc, there is no need to change the number of rotations between the recording position and the reproducing position. Therefore, the time between the recording operation and the reproducing operation can be shortened and the operation efficiency can be improved. Due to this improvement in operation efficiency, the video / audio signal can be encoded at a high encoding rate for recording and reproduction.

Further, the simultaneous recording / reproducing apparatus of the present invention records the video / audio signal of a certain program on the recording medium, performs the recording operation, and reproduces the video / audio signal recorded by that time, that is, chasing. Play. During the simultaneous recording / reproduction, the rotation speed of the optical disk is kept constant at a rotation speed suitable for the zone in which the recording operation is performed, and the reproduction is performed at the same rotation speed even during the reproduction. When performing this simultaneous recording / playback, obtain the bit rate for encoding the video / audio signal when the data of the zone with the maximum rotation speed is read out using the optimum rotation speed for the zone with the minimum rotation speed. It should be less than the maximum data rate. Even if the playback operation must be performed in the innermost zone when the rotation speed is controlled in the minimum state, that is, when the recording operation is performed in the outermost zone, the recorded data Since the rate is a value that can guarantee the data rate even when the data in the innermost circumferential zone is read in the state where the number of rotations is minimum, the real-time property of the video and audio signal obtained by decoding can be guaranteed.

Further, the simultaneous multi-channel reproducing apparatus of the present invention reproduces the code strings of a plurality of video / audio signals simultaneously from a recording medium in which the code strings of a plurality of video / audio signals are recorded in a time division manner. To do. During the simultaneous multi-channel reproduction, the rotation speed of the optical disk is kept constant at a rotation speed suitable for the inner zone, and even when the data is reproduced from the outer zone, the reproduction is performed at the same rotation speed. Since the margin for reproducing the data from the disc is very large, even if the data is reproduced from the outer zone with the high rotation speed suitable for the inner zone, the reproduction can be correctly performed. By performing such an operation, it is not necessary to change the number of rotations at the reproduction position even in the case of a CLV or ZCLV disc when the reproduction operation of one channel is changed to the reproduction operation of another channel in the simultaneous recording / reproduction. . Therefore, the time required to move the zone can be shortened and the operation efficiency can be improved. Due to this improvement in operation efficiency, it is possible to reproduce a code string of a video / audio signal with a high coding rate on multiple channels. In addition, since the number of revolutions of the inner zone is adjusted, the data rate when reproducing the data recorded in the inner zone can be guaranteed.

Further, preferably, during the simultaneous multi-channel reproduction, the rotation speed of the optical disk is kept constant at a rotation speed suitable for the innermost circumferential zone, and even when data is reproduced from the outer zone, the reproduction is performed at the same rotation speed. To do. By performing the reproduction at the rotational speed of the innermost zone or more, the data rate for reproducing the data can be guaranteed regardless of which zone the data is reproduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a simultaneous recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing the concept of chasing playback in the first embodiment of the present invention.

FIG. 3 is a schematic diagram showing a data flow in chasing playback for explaining the first embodiment of the present invention.

FIG. 4 is a schematic diagram showing recording positions on the optical disc according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram showing a data flow in chasing playback for explaining the first embodiment of the present invention.

FIG. 6 is a block diagram of a simultaneous recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 7 is a schematic diagram showing a data flow in chasing playback for explaining the second embodiment of the present invention.

FIG. 8 is a schematic diagram showing a data flow in chasing playback for explaining the second embodiment of the present invention.

FIG. 9 is a block diagram of a simultaneous recording / reproducing apparatus according to a fourth embodiment of the present invention.

FIG. 10 is a schematic diagram showing a data flow in chasing playback for explaining the fourth embodiment of the present invention.

FIG. 11 is a schematic diagram showing a situation of recording and reproducing data in chasing reproduction for explaining the fourth embodiment of the present invention.

FIG. 12 is a block diagram of a simultaneous recording / reproducing apparatus according to a fifth embodiment of the present invention.

FIG. 13 is a schematic diagram showing an example of a display according to the fifth embodiment of the present invention.

FIG. 14 is a block diagram of a simultaneous recording / reproducing apparatus according to a sixth embodiment of the present invention.

FIG. 15 is a schematic diagram showing recording positions on an optical disc.

FIG. 16 is a schematic diagram showing a zone arrangement on an optical disc.

FIG. 17 is a block diagram of a simultaneous multi-channel reproducing device according to an eighth embodiment of the present invention.

FIG. 18 is a schematic diagram showing a data flow in simultaneous multi-channel reproduction.

FIG. 19 is a schematic diagram showing a zone arrangement on an optical disc.

FIG. 20 is a schematic diagram showing the structure of a code string in simultaneous multi-channel reproduction.

[Explanation of symbols]

101 video / audio encoder 102, 105, 603, 604 buffer memory 103, 106 buffer amount counter 104, 605, 606 video / audio decoder 107 recording / reproducing signal processor 108, 601, 607, 901, 1202, 140
8, 1707 System controller 109, 609, 909, 1708 Optical disk 110 Data selector 1411, 1709 Optical head 1412 Motor 1701 Reproduction signal processor 1702 Data selector 1703, 1704 Buffer memory 1705, 1706 Video / audio decoder

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaaki Kondo 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Yuji Takagi, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Keiichi Kawashima 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-8-279976 (JP, A) JP-A-10-162507 (JP, A) JP-A-9-213055 (JP, A) JP-A-8-138318 (JP, A) JP-A-10-56620 (JP, A) JP-A-11-120698 (JP, A) JP-A-11-273246 (JP, A) JP 10-322662 (JP, A) JP 11-187352 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 20/10 G11B 27 / 00 H04N 5/75 H04N 5/91

Claims (3)

(57) [Claims] 1. A first code string storing an input first code string
Buffer memory means, and inputting the first code string to the first buffer memory
Data input means and the first code read from the first buffer memory.
Data recording means for recording the signal sequence on the recording medium, and the first code recorded on the recording medium before a certain time.
And data reproducing means for reading No. column as a second code string, the second code string read out by said data reproducing means
And a second buffer memory means for storing the second code string from the second buffer memory means.
Data output means for reading , recording position of the first code string on a recording medium, and recording medium
From the playback position of the second code sequence from
The raw position catches up with the position a predetermined time before the recording position.
And recording the second code string by the data reproducing means.
When reading from the medium, normal playback operation or stop state
Is the system control hand that switches to any of the suspended states.
The playback position is added to a position a predetermined time before the recording position.
Characterized by being configured to display when
Simultaneous recording / playback device. 2. The reproduction position is a predetermined time from the recording position.
A letter, sign, or icon that you have caught up with in the previous position
The simultaneous recording according to claim 1, characterized in that
Playback device. 3. A first code string for accumulating the input first code string
Buffer memory means, and inputting the first code string to the first buffer memory
Data input means and the first code read from the first buffer memory.
A data record that records a sequence of signals on a recording medium for each predetermined amount of data.
Recording means and the first recording means recorded on the recording medium a certain time ago.
Data reproducing means for reading the code string of
And the second code string read by the data reproducing means
And a second buffer memory means for storing the second code string from the second buffer memory means.
A data output means for reading and a data storage amount of the first buffer memory means are monitored.
System control means for controlling the data recording means and the data recording means.
The data is recorded on the recording medium alternately by the data reproducing means.
The first buffer memory for performing the recording operation and the reproducing operation
Detected that the data storage amount of the means exceeded the first predetermined amount
Then, from the recording medium by the data reproducing means
The reading of the second code string is temporarily stopped, and the data
Writing of the first code string on the recording medium by a recording means
Control is performed so that the imprinting is continuously performed for each of the predetermined data amount.
And the recording position and data by the data recording means.
The reproducing position by the reproducing means is the position on the recording medium.
When the distance is more than a certain value,
Simultaneous recording / reproducing apparatus characterized by prohibiting reproducing operation
Place