JP4006373B2 - Simultaneous recording and playback device - Google Patents

Description

  The present invention relates to a simultaneous recording / reproducing apparatus that records a video / audio signal on a recording medium and performs chasing reproduction.

  Home video tape recorders (VTRs) are widely spread and used in general households. One of the main methods of using a home VTR is reserved recording, and recording and playback of video / audio signals are performed under the concept of time shift.

  However, when the scheduled recording is set in the home VTR, the recorded content cannot be viewed before the scheduled recording end time, for example. In other words, there is a disadvantage that the recorded contents can only be viewed after waiting for the scheduled recording to end. In order to solve such a problem, Japanese Patent Application Laid-Open No. 6-14288 proposes a method for allowing the content being recorded to be freely viewed from the beginning before the scheduled recording ends. A method of allowing a user to freely view the recorded content from the beginning of the recorded content even during recording is generally called chasing playback.

  On the other hand, a zone CLV (Constant Linear Velocity) method (hereinafter referred to as ZCLV method) is adopted as a recording method for DVD-RAM and the like. The ZCLV method is a method in which a recording medium is divided into a plurality of areas (zones) in the radial direction, and the inside of the zone is recorded by a CAV (Constant Angular Velocity) method. Further, the rotational speed is different between the zones, and the rotational speed becomes faster in the inner peripheral zone. That is, the ZCLV method is used because the range of the recording power margin during recording is limited, and the linear velocity must be within a certain range.

  However, the above conventional technique has the following various problems. When the buffer amount on the recording side overflows, data to be recorded is interrupted. Further, in order to perform chasing playback, it is necessary to increase the data writing / reading speed to / from the medium as compared with the case of only playback. Further, when the playback position catches up with the recording position due to high-speed playback or the like, it is not known that the user has caught up. Further, when the playback position catches up with the recording position, the playback video is disturbed.

  Further, in a recording medium for recording by the ZCLV method or the CLV method, the optimum rotation speed varies depending on the recording position. However, in the above conventional technique, when chasing playback is performed on such a recording medium, the number of rotations is different between the recording position and the playback position, and the recording operation is switched to the playback operation (or vice versa). , The same shall apply hereinafter), and the rotational speed must be changed. When changing the rotation speed, it takes time for the rotation speed to stabilize, and thus it takes time to move from the recording operation to the reproduction operation. In order to increase the data rate at which the follow-up reproduction is possible, it is necessary to shorten the time from the recording operation to the reproduction operation as much as possible. Therefore, if the rotation speed needs to be changed when moving from the recording operation to the reproduction operation as described above, the data rate at which the follow-up reproduction becomes possible becomes small. For example, when the audio / video signal is encoded and recorded. Causes deterioration in image quality and sound quality.

  As described above, the conventional methods have many problems. SUMMARY OF THE INVENTION An object of the present invention is to solve the conventional problems and to provide a simultaneous recording / reproducing apparatus in which the recording-side buffer amount does not overflow.

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

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

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

  In addition, the present invention provides a simultaneous recording / reproducing apparatus capable of recording / reproducing at a high data rate even when simultaneous recording / reproducing, chasing reproduction, and simultaneous multi-channel reproduction are performed using a recording medium that records in the ZCLV method or the CLV method. It is another object of the present invention to provide a simultaneous multi-channel playback device.

The first simultaneous recording / reproducing apparatus of the present invention comprises: first buffer memory means for storing the inputted first code string; data input means for inputting the first code string to the first buffer memory; Data recording means for recording the first code string read from the first buffer memory on the recording medium, and data reproduction for reading the first code string previously recorded on the recording medium for a certain time as the second code string Means, second buffer memory means for accumulating the second code string read by the data reproducing means, data output means for reading the second code string from the second buffer memory means, and first buffer memory means System control means for monitoring the data storage amount. The system control means causes the data recording means and the data reproducing means to perform recording and reproducing operations on the recording medium alternately in time, and the data storage amount of the first buffer memory means exceeds the first predetermined amount. Is detected, the reading of the second code string from the recording medium by the data reproducing means is temporarily stopped, and control is performed so that the first code string is continuously written to the recording medium by the data recording means.
For example, in the simultaneous recording / reproducing apparatus, when it is detected that the data storage amount of the first buffer memory means exceeds the first predetermined amount and then becomes the second predetermined amount or less, the system control means again The data recording means and the data reproducing means are caused to perform recording operations and reproducing operations on the recording medium alternately in time.
Further, for example, in the simultaneous recording / reproducing apparatus, when the system control means detects that the amount of data stored in the second buffer memory means is equal to or less than a third predetermined amount, the second buffer by the data output means Reading of the second code string from the memory means is temporarily stopped.
Further, for example, in the simultaneous recording / reproducing apparatus, when the system control unit further detects that the data accumulation amount of the second buffer memory unit is equal to or less than a third predetermined amount, the second unit by the data output unit Control to temporarily stop reading of the second code string from the buffer memory means, and after the data storage amount of the second buffer memory means becomes equal to or less than the third predetermined amount, Then, the data output means again controls to read the second code string from the second buffer memory means.
In the simultaneous recording / reproducing apparatus, for example, the data input means includes encoding means for encoding the input first signal into a first code string, and the data output means includes the second buffer memory. Decoding means for reading the second code string from the means, decoding it and outputting it as a second signal is provided.

  The second simultaneous recording / reproducing apparatus of the present invention includes an encoding means for encoding the input first signal into a first code string, and a first code string encoded by the encoding means. First buffer memory means for storing, data recording means for recording the first code string read from the first buffer memory on the recording medium, and the first code string recorded on the recording medium previously for a certain time Is read out as a second code string, second buffer memory means for accumulating the second code string read out by the data reproducing means, and the second code string is read out from the second buffer memory means. A decoding means for decoding and outputting as a second signal; and a system control means for setting the coding rate of the first signal in the coding means, wherein the data recording means and the data reproducing means are alternately arranged in time. Record When the system control means is set to the simultaneous recording / reproducing mode in which the first signal is recorded and the second signal is reproduced at the same time, only the first signal is recorded. The encoding rate of the encoding means is made smaller than when the normal recording mode is set. For example, the system control means sets the encoding rate set in the encoding means in the simultaneous recording / reproducing mode to ½ or less of the encoding rate in the normal recording mode.

  The third simultaneous recording / reproducing apparatus of the present invention includes an encoding means for encoding the input first signal into a first code string, and a first code string encoded by the encoding means. First buffer memory means for storing, data recording means for recording the first code string read from the first buffer memory on the recording medium, and the first code string recorded on the recording medium previously for a certain time Is read out as a second code string, second buffer memory means for accumulating the second code string read out by the data reproducing means, and the second code string is read out from the second buffer memory means. Decoding means for decoding and outputting as a second signal, and system control means for setting the encoding rate of the first signal in the encoding means. Here, the system control means causes the data recording means and the data reproducing means to perform the recording operation and the reproducing operation on the recording medium alternately in time. In addition, when the system control means is set to the simultaneous recording / reproducing mode in which the recording of the first signal and the reproducing of the second signal are simultaneously performed, the total value of the recording rate and the reproducing rate for the 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.

  The third simultaneous recording / reproducing apparatus of the present invention includes an encoding means for encoding the input first signal into a first code string, and a first code string encoded by the encoding means. First buffer memory means for storing, data recording means for recording the first code string read from the first buffer memory on the recording medium, and the first code string recorded on the recording medium previously for a certain time Is read out as a second code string, second buffer memory means for accumulating the second code string read out by the data reproducing means, and the second code string is read out from the second buffer memory means. Decoding means for decoding and outputting as a second signal, and system control means for setting the encoding rate of the first signal in the encoding means. The system control means causes the data recording means and the data reproducing means to perform a recording operation and a reproducing operation on the recording medium alternately in time. Here, the encoding means performs encoding at a variable bit rate, and lowers 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 includes first buffer memory means for storing the inputted first code string, and data input means for inputting the first code string to the first buffer memory. Data recording means for recording the first code string read from one buffer memory on the recording medium, and data for reading the first code string previously recorded on the recording medium for a certain time as the second code string Reproducing means, second buffer memory means for accumulating the second code string read by the data reproducing means, data output means for reading the second code string from the second buffer memory means, and first code string System control means for monitoring the recording position on the recording medium and the reproduction 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 unit switches the reading of the second code string from the recording medium by the data reproduction unit to the normal reproduction operation, the stop state, or the pause state.
In this simultaneous recording / reproducing apparatus, for example, even if the reproduction position catches up with the recording position within a predetermined time, the data reproduction means reads the second code string from the recording medium.
In this simultaneous recording / reproducing apparatus, preferably, when the reproduction position catches up with the recording position within a predetermined time, the system control means notifies the display character generation means that the reproduction position has caught up within the predetermined time of the pre-recording position. The display character generation means generates a character string indicating that the reproduction position has caught up within a predetermined time of the recording position and displays it to the user. The display character generation means generates a symbol, for example. In the simultaneous recording / reproducing apparatus, the predetermined time is 0, for example.

In each of the above-described simultaneous recording / reproducing apparatuses, for example, the first and second code strings are code strings obtained by encoding video or audio signals.
In each of the above-described simultaneous recording / reproducing apparatuses, for example, the recording operation and the reproducing operation with respect to the recording medium are performed by the same head.
In each of the above-described simultaneous recording / reproducing apparatuses, for example, the recording medium is an optical disk.
In each of the above-described simultaneous recording / reproducing apparatuses, for example, the system control unit updates management data related to data recorded on the recording medium, for example, at regular intervals between recording and reproduction.
In each of the above-described simultaneous recording / reproducing apparatuses, for example, the system control unit may alternately change the time when the recording position by the data recording unit and the reproduction position by the data reproducing unit are separated from each other by a predetermined distance on the recording medium. Recording and playback operations are prohibited.

A fifth simultaneous recording / reproducing apparatus of the present invention is a simultaneous recording / reproducing apparatus using a recording medium having an optimum number of rotations depending on a recording position, and motor means for rotating the recording medium, and the input first code string First buffer memory means for storing data, 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 as a recording medium Data recording means for recording, data reproducing means for reading out the first code string recorded on the recording medium before a certain time as a second code string, and the second code read by the data reproducing means Second buffer memory means for accumulating strings, data output means for reading out the second code string from the second buffer memory means, and the data recording means on the recording medium. And a system control means for controlling the number of rotations of the motor means, and the data recording means and the data reproducing means perform recording on the recording medium alternately in time. A reproduction operation is performed, and the system control means maintains the number of rotations determined by the position where the first code string is recorded during the recording / reproduction operation.
For example, the first code string includes at least a code string obtained by encoding a video signal or an audio signal.
Further, for example, the system control means causes the data recording means to record from the outer peripheral zone toward the inner peripheral zone. Also, for example, the system control means causes the data recording means to record 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 in a certain unit within the zone from the outside to the inside.
Further, for example, the rotational speed is within a predetermined margin with respect to the optimal rotational speed determined by the position where the first code string is recorded.

  The sixth simultaneous recording / reproducing apparatus of the present invention is a simultaneous recording / reproducing apparatus that uses a recording medium having an optimum number of rotations at the time of recording depending on the recording position, and is inputted with motor means for rotating the recording medium. Encoding means for encoding a first signal into a first code string; first buffer memory means for storing the first code string encoded by the encoding means; and the first buffer Data recording means for recording the first code string read from the memory on a recording medium, and data reproducing means for reading the first code string previously recorded on the recording medium for a certain time as a second code string; A second buffer memory means for accumulating the second code string read out by the data reproducing means; and reading out the second code string from the second buffer memory means for decoding into a second signal. Decoding means for outputting, and system control means for monitoring the position where the data recording means records the first code string on a recording medium and controlling the number of revolutions of the motor means, the data recording means And the data reproducing means perform recording / reproducing operations performed on the recording medium alternately in time, and the system control means performs the recording / reproducing operation according to the position where the first code string is recorded while performing the simultaneous recording / reproducing operation. A first rotational speed that is determined, and the encoding means uses the second rotational speed that is optimal for the recording position at which the rotational speed on the recording medium is minimized, and performs recording with the maximum rotational speed on the recording medium. The first signal is encoded with a value less than or equal to the maximum data rate obtained when position data is read.

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

In each of the simultaneous recording / reproducing apparatuses described above, for example, the first signal includes at least a video signal or an audio signal.
For example, the recording method of the recording medium is the CLV method or the ZCLV method.
Further, for example, the recording operation and the reproducing operation with respect to the recording medium are performed by the same head.
For example, the recording medium is an optical disk.
Preferably, the system control means causes the data recording means to record in a continuous free area when performing a recording / reproducing operation performed on a recording medium alternately in time.

  The simultaneous multi-channel playback device of the present invention is a simultaneous multi-channel playback device that uses a recording medium on which at least two or more code strings are recorded, and the optimum rotation speed at the time of playback differs depending on the playback position, Motor means for rotating the recording medium, data reproducing means for performing a reproducing operation for alternately reading out the plurality of code strings from the recording medium, and a position at which the data reproducing means reproduces the code string from the recording medium And system control means for maintaining the rotational speed of the motor means during the reproducing operation so as to achieve the rotational speed for reproducing the code string recorded on the inner circumference side of the recording medium.

In addition, for example, the system control means maintains the rotational speed of the motor means during the reproducing operation so that it is equal to or higher than the rotational speed for reproducing the code string recorded on the innermost circumference of the recording medium.
For example, the recording medium is an optical disk.
For example, the recording method of the recording medium is the CLV method or the ZCLV method.
For example, the code string is a code string obtained by encoding 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.

  In the simultaneous recording / reproducing apparatus of the present invention, a video / audio signal of a certain program is recorded on a recording medium, and a video / audio signal which has already been recorded after a lapse of time while performing a recording operation is reproduced, that is, chasing. During the simultaneous recording playback or chasing playback, the recording side and playback side buffer amounts are monitored, and if the recording side buffer amount exceeds a predetermined amount, the playback operation is paused, and then the recording operation is performed continuously. 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 when the buffer amount on the recording side increases when the seek operation between the reproducing operation and the recording operation takes too much time, the data recording on the recording medium is guaranteed.

  The simultaneous recording / reproducing apparatus of the present invention has two modes, a normal recording mode and a chasing reproduction mode. When the chasing reproduction mode is set, a video / audio signal having a length of time that is the normal recording mode is recorded. The encoding rate when the audio / video signal encoding apparatus encodes the audio / video signal is set so that both the recording and reproduction operations of the audio / video signal having the same time length can be performed within the same time. . With such an operation, when the chasing playback mode is set, chasing playback can be performed without causing overflow or underflow of the buffer memory. In the normal recording mode, the encoding rate can be set to a high encoding rate in accordance with the capability of the recording medium. Therefore, in the normal recording mode, video and audio with high image quality and high sound quality can be obtained. In addition, since recording and playback are performed simultaneously in the chasing playback mode, simultaneous recording playback and chasing playback can be realized without the need to increase the transfer rate of the recording medium.

  In the simultaneous recording / reproducing apparatus of the present invention, at the time of simultaneous recording / reproducing or chasing reproduction, when high-speed reproduction is performed and the reproduction position catches up with the recording position, the high-speed reproduction operation is canceled and the normal reproduction operation is performed, and reproduction is performed. Prevent the position from overtaking the recording position. Since the playback position does not overtake the recording position by such an operation, it is possible to prevent meaningless data from being played and disturb the video and audio.

  The simultaneous recording / reproducing apparatus of the present invention shifts to the normal reproduction operation when the high-speed reproduction operation is canceled and the normal reproduction operation is shifted to the normal reproduction operation when the reproduction position catches up with the recording position at the time of the chasing reproduction. On the screen. By performing such an operation, the user can be notified of the automatic transition from the high-speed operation to the normal operation, the user can know why the high-speed operation has been switched to the normal operation, and is user-friendly. A user interface can be provided.

  Further, the simultaneous recording / reproducing apparatus of the present invention records an audio / video signal of a program on a recording medium and performs an operation of reproducing the audio / video signal recorded up to that point while performing the recording operation, that is, chasing reproduction. . At the time of the simultaneous recording and reproduction, the rotation speed of the optical disk is constant at a rotation speed suitable for the zone where the recording operation is performed, and reproduction is performed with the rotation speed even at the time of reproduction. Reproduction of data from a disc has a much larger margin than recording, so that data can be reproduced correctly even if data is reproduced from a different zone with the rotation speed suitable for the zone being recorded. By performing such an operation, when moving from the recording operation to the reproducing operation or from the reproducing operation to the recording operation in simultaneous recording / reproducing, the rotational speed is changed between the recording position and the reproducing position even in the case of a CLV or ZCLV disc. There is no need. Therefore, the time between the recording operation and the reproducing operation can be shortened, and the operation efficiency can be improved. By improving the operation efficiency, the audio / video signal can be encoded and recorded and reproduced at a high encoding rate.

  Further, the simultaneous recording / reproducing apparatus of the present invention records an audio / video signal of a program on a recording medium and performs an operation of reproducing the audio / video signal recorded up to that point while performing the recording operation, that is, chasing reproduction. . At the time of the simultaneous recording and reproduction, the rotation speed of the optical disk is constant at a rotation speed suitable for the zone where the recording operation is performed, and reproduction is performed with the rotation speed even at the time of reproduction. When performing simultaneous recording and playback, the bit rate for encoding the audio / video signal is obtained when the data of the zone with the maximum number of rotations is read using the optimal number of rotations for the zone with the minimum number of rotations. The value is less than or equal to the maximum data rate allowed. Even if the playback operation must be performed in the innermost zone when the control is performed with the minimum number of revolutions, that is, the recording operation is performed in the outermost zone, the recorded data This rate is a value that can guarantee the data rate even if the data in the innermost zone is read out with the rotation speed being minimum, so that the real-time property of the video / audio signal obtained by decoding can be guaranteed.

  The simultaneous multi-channel playback device of the present invention simultaneously plays back the code strings of a plurality of video / audio signals in a time division manner from a recording medium on which a code string obtained by encoding a plurality of video / audio signals is recorded. At the time of simultaneous multi-channel reproduction, the rotation speed of the optical disk is constant at a rotation speed suitable for the inner zone, and reproduction is performed with the rotation speed even when data is reproduced from the outer zone. The reproduction of data from the disc has a very large margin, so that even if data is reproduced from the outer zone while maintaining a high rotation speed suitable for the inner zone, it can be reproduced correctly. By performing such an operation, it is not necessary to change the number of rotations at the playback position even in the case of a CLV or ZCLV disc when shifting from the playback operation of one channel to the playback operation of another channel in simultaneous recording and playback. . Therefore, the time for zone movement can be shortened, and the operation efficiency can be improved. By improving the operation efficiency, it is possible to reproduce a multi-channel code string of a high coding rate for the video / audio signal. In addition, since the speed is matched with the rotation speed of the inner zone, the data rate when reproducing the data recorded in the inner zone can be guaranteed.

  Preferably, at the time of simultaneous multi-channel reproduction, the rotation speed of the optical disc is constant at a rotation speed suitable for the innermost zone, and reproduction is performed with the rotation speed even when data is reproduced from the outer zone. By performing the reproduction at the rotational speed of the innermost zone or higher, it is possible to guarantee the data rate when reproducing the data from any zone.

  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.

(Embodiment 1)
FIG. 1 shows a simultaneous recording / reproducing apparatus according to the 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 / reproduction signal processor 107, a system controller 108, an optical disc 109, and data. It consists of a selector 110.

  Next, the normal operation of the simultaneous recording / reproducing apparatus will be described. First, the operation during recording will be described. The video / audio signal A is encoded by the video / audio encoder 101 to be an encoded sequence. For example, when the video / audio encoder 101 is an MPEG encoder, the video code sequence generated by MPEG encoding the video signal of the video / audio signal A and the audio signal of the video / audio signal A are encoded by MPEG. The audio code string generated by the AC-3 encoding is multiplexed into an MPEG system code string, which is output from the video / audio encoder 101. The code string output from the video / audio code string 101 is stored in the first buffer memory 102. The code string stored in the first buffer memory 102 is read out by the data selector 110 and input to the recording / reproducing signal processor 107, and 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 103 counts the amount of data input to and output from the first buffer memory 102 and obtains the amount of data stored in the first buffer memory 102.

  Next, the operation during reproduction will be described. The signal read from the optical disk 109 is binarized, demodulated, ECC processed, etc. by the recording / reproducing signal processor 107 to become a code string, and then input to the second buffer memory 105 via the data selector 110. Is done. The code string read from the second buffer memory 105 is decoded by the video / audio decoder 104 to become a video / audio signal B. The second buffer amount counter 106 counts the amount of data input / output to / from the second buffer memory 105 to obtain the data amount stored in the second buffer memory 105.

  Switching between recording and reproduction operations is performed by the system controller 108. The system controller 108 controls whether to reproduce data from the optical disk 109 or to record data on the optical disk 109 depending on whether the reproduction operation or the recording operation is performed. The data selector 110 is also controlled so that data flows from the first buffer memory 102 to the recording / reproducing signal processor 107 during recording, and data flows from the recording / reproducing signal processor 107 to the buffer memory 105 during reproduction.

  Next, chasing playback in the synchronous recording / playback apparatus shown in FIG. 1 will be described. FIG. 2 is a schematic diagram showing the concept of chasing playback, and shows the recording and playback states when a certain program is chased and played back. First, recording of a certain program is started ((a) of FIG. 2). The hatched portion in FIG. 2 (a) indicates that recording has been performed on the optical disc. Then, after recording for a certain time, reproduction is started from the beginning of the program ((b) of FIG. 2). However, even if playback is started, recording does not stop and recording continues. FIG. 2C shows a state after a certain time has elapsed from the start of reproduction. In FIG. 2C, the part 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 disc 109 are simultaneously performed in a time division manner.

  The operation of the simultaneous recording / reproducing apparatus in the state shown in FIG. 2C will be described with reference to FIG. FIG. 3 is a schematic diagram showing the state of access to the optical disc 109, reading / writing of data to / from the buffer memories 102 and 105, and temporal changes of the audio / video signals A and B. The same symbol indicates the same data, or the same data encoded and decoded. FIG. 3 shows a case where the amount of data read from and written to the buffer and the disk is the same. As shown in FIG. 3A, the access to the optical disc 109 is alternately read and written. In FIG. 3A, the data indicated by hatching indicates data reproduced from the optical disc 109, and the data not indicated by hatching indicates data recorded on the optical disc 109. For example, after data a is recorded at time 301, the reproduction position of data b is searched at time 302, and 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. It is assumed that data to be recorded is recorded on continuous tracks. Also, 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, n, p are recorded on the track 420. Let's say. In this case, after data a is recorded in area 401, the head of area 402 is searched and data b is reproduced from area 402. After the data b is reproduced, the head of the area 403 is searched and the data c is recorded in the area 403. For example, a sector, an ECC block, and a plurality of ECC blocks can be considered as the area here.

  The data i, k, m, etc. recorded on the optical disc 109 are encoded as the audio / video signal A as shown in (f) of FIG. 102 is written. The timing is shown in FIG. The data written at the timing of FIG. 3D is accumulated in the first buffer 102 for a certain time, and then read from the first buffer memory 102 at the timing as shown in FIG. 3 is recorded on the optical disc 109 at the timing (a).

  Data b, d, f, etc. reproduced from the optical disc 109 are read as shown in FIG. Then, the data is written into the second buffer memory 105 as shown in FIG. The data written in the second buffer memory 105 at the timing shown in FIG. 3C is stored in the second buffer 105 for a certain period of time, and then the second buffer memory 105 is shown at the timing shown in FIG. Are read out to the video / audio decoder 104 and reproduced at the timing shown in FIG.

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

  The video / audio signal A is continuously input as shown in FIG. Therefore, data writing to the first buffer memory 102 is also performed as usual as shown in FIG. However, as shown in FIG. 5B, reading from the first buffer memory 102 reduces the amount of data to be read by the amount of time that is required for the search of the optical disc 109. As a result, the amount of data stored in the first buffer memory 102 becomes larger than usual as shown in FIG. When the data o is recorded in the first buffer 102 (time 513), the amount of data stored in the first buffer memory 102 exceeds the first predetermined amount. When the amount of data stored in 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 has exceeded the first predetermined amount, the system controller 108 pauses the data reproduction operation from the optical disk 109. Then, the data recording operation on the optical disk 109 is preferentially performed continuously until the data accumulation amount of the first buffer memory 102 becomes equal to or less than the second predetermined amount. In this example, the second predetermined amount is the same as the first predetermined amount. That is, after the data g is recorded at time 504 (until time 505), the data accumulation amount in the first buffer memory 102 is inspected. At this time, as shown in (h) of FIG. 5, the amount of data stored in the first buffer memory 102 exceeds the second predetermined amount, so that data i is continuously recorded on the optical disc 109. At the time point when the recording of the data i is completed (time 506), the amount of data stored in the first buffer memory 102 is equal to or less than the second predetermined amount. Here, since writing to the first buffer memory 102 is performed, data k is subsequently written to the optical disk 109. At the time point when the recording of the data k on the optical disk 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. In order to read, the head position of the data h is searched.

  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 data is not read because the amount of data stored in the buffer memory 105 is zero. Therefore, there is no video / audio signal B to be output from the video / audio decoder 104 at time 510. 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, 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.

  As described above, the simultaneous recording / reproducing apparatus of the present embodiment records the video / audio signal of a certain program on the recording medium, and reproduces the video / audio signal that has already been recorded after a certain period of time while performing the recording operation. Chasing playback. During the simultaneous recording playback or chasing playback, the recording side and playback side buffer amounts are monitored, and if the recording side buffer amount exceeds the first predetermined amount, the playback operation is paused, and then continuous recording is performed. 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. By such an operation, it takes time for the seek operation between the reproduction operation and the recording operation, and even when the buffer amount on the recording side increases, the data recording on the recording medium is surely guaranteed.

  Although FIG. 4 shows the case where time-continuous data is recorded in a continuous area, the data recording position may not be a continuous area.

In this embodiment, the case where the amount of data read / written at the same time in the buffer memory and the optical disc is the same, but the amount of data may be different each time data is read / written. Further, the amount of data accessed at one time in reading / writing with respect to the buffer memory and reading / writing with respect to the optical disk may be different. In addition, the amount of data accessed at one time when reading data and when writing data to the buffer memory or the optical disk may be different.
The first and second buffer memories 102 and 105 may be configured using the same memory. For example, it is used from the beginning of the memory space for reproduction, and from the end for recording.

  In the present embodiment, the case where the search is slow and the amount of data stored in the buffer memory exceeds a predetermined amount has been described. However, the simultaneous recording / reproducing apparatus of this embodiment can also be used 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 when, for example, recording / reproduction is performed at a variable bit rate, the total bit rate of the reproduction side bit rate and the recording side bit rate is higher than the predetermined bit rate. This is when it becomes higher. Such a situation also occurs when learning about recording / playback conditions, when there is a defective sector, or when writing to a file management area (TOC area). In recording learning, parameters such as recording drive and focus for servo are learned and optimized during recording. For example, focus learning must be performed when a drive temperature difference occurs with time. During learning, the actual data recording / reproducing operation is stopped. As a result, the recording buffer may overflow. A defective sector is detected when the sector address cannot be read. When a defective sector is detected, processing such as skipping the sector and recording in the next sector or recording in an alternative sector is performed. Therefore, there is a possibility that the recording operation is temporarily stopped and the recording buffer overflows. The file management data is usually stored in the memory of the system controller, and after all the data (for example, data for one program) has been recorded, the management data is recorded on the disk. However, a system that manages file management data on a disk after recording a certain amount of time or a certain amount of data is also conceivable. In that case, the recording / reproducing operation of AV data is stopped while the file management data is being recorded, so the recording buffer may overflow.

  In the present embodiment, the first predetermined amount with respect to the data accumulation amount of the first buffer memory 102 when the reproduction from the optical disc 109 is paused, and the data accumulation amount of the first buffer memory 102 to resume the reproduction. Although the case where the second predetermined amount is the same amount has been described, these may be different values.

  In order to prevent the underflow of the reproduction buffer 105, for example, when the system controller 108 detects that the amount of data stored in the second buffer memory 105 is equal to or less than a third predetermined amount, the video / audio decoder The reading of the second code string from the second buffer memory 105 by 104 is temporarily stopped. Further, when the data storage amount in the second buffer memory 105 exceeds the third predetermined amount and then exceeds the fourth predetermined amount, the system controller 108 again causes the video / audio decoder 104 to return from the second buffer memory 105. Control to read the second code string. The third predetermined amount and the fourth predetermined amount may be the same amount or different amounts.

(Embodiment 2)
FIG. 6 shows a simultaneous recording / reproducing apparatus according to the second embodiment of the present invention. The simultaneous recording / playback apparatus includes a video / audio encoder 101, buffer memories 102 and 105, a video / audio decoder 104, a recording / playback signal processor 107, a system controller 601, an optical disk 609, and a data selector 110. However, this simultaneous recording / reproducing apparatus differs 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, the encoding rate can be changed. For example, when recording / reproduction is performed at a variable bit rate, when the total bit rate of the reproduction-side bit rate and the recording-side bit rate is higher than a predetermined bit rate, the data storage amount of the buffer memory is reduced to a predetermined amount. Exceed. Therefore, as will be described later, when the recording buffer is about to overflow, the system controller 601 sets the encoding bit rate at the time of simultaneous recording / reproduction low.

  The basic operation of the simultaneous recording / reproducing apparatus is the same as the normal operation described in the first embodiment. An 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 is a schematic diagram showing the status of access to the optical disc 609, reading / writing of data to / from the first buffer memory 102, and temporal change of the video / audio signal A. FIG. In the normal recording mode, only the audio / video signal A is recorded, and the reproduction operation from the optical disk 609 is not performed. 7 in which the same symbol is used indicates that the same data or the same data is encoded and decoded. Further, FIG. 7 shows a case where the amount of data read / written at one time from the buffer and the optical disk is the same. As shown in FIG. 7F, the data g, i, k, etc. recorded on the optical disc 609 are encoded by the video / audio encoder 101 as the video / audio signal A, and are first buffered. It is written in the memory 102. The timing is shown in FIG. The data written at the timing shown in FIG. 7D is accumulated in the buffer 102 for a certain time, and then read from the first buffer memory 102 at the timing shown in FIG. 7B. Is recorded on the optical disk 609 at the timing (a).

  Next, the operation in the chasing playback mode will be described with reference to FIG. When the chasing playback mode is set, as described below, both the recording and playback of the video / audio signal of the same time length within the same time as the video / audio signal of the time length that is the normal recording mode are recorded. The encoding rate when the audio / video signal encoder 101 encodes the audio / video signal is set so that the operation can be performed. FIG. 8 schematically shows the status of access to the optical disc 609, reading / writing of data to / from the first buffer memories 102 and 105, and temporal changes in the audio / video signals A and B. 8 where the same symbol is used as in FIG. 7 indicates that the same data or the same data is encoded and decoded. Further, FIG. 8 shows a case where the amount of data read / written at the same time in the buffer and the disk is the same. When the chasing playback mode is set, the system controller 601 sets the video / audio encoder 101 so that the encoding 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 of encoding by the video / audio encoder 101 is low. In addition, it can be seen that while the video / audio signal having a certain length of time is recorded in the normal recording mode, both the recording / playback processing of the video / audio signal having the same time length is performed in the chasing playback mode. For example, in the chasing playback mode, the encoding rate in the video / audio encoder 101 may be ½ or less compared to that in the normal recording mode.

  As shown in FIG. 8A, the access to the optical disc 609 is alternately read and written. In FIG. 8A, the data indicated by hatching indicates data reproduced from the optical disc 609, and the data not indicated by hatching indicates data recorded on the optical disc 609. As shown in FIG. 8F, the data i, k, m, etc. recorded on the optical disc 609 are encoded as the audio / video signal A and encoded by the audio / video encoder 101, as shown in FIG. It is written in the memory 102. The timing is shown in FIG. The data written at the timing shown in FIG. 8D is accumulated in the buffer 102 for a certain time, and then read from the first buffer memory 102 at the timing shown in FIG. 8B. Is recorded on the optical disk 609 at the timing (a).

  When reading is described, data b, d, f, and the like reproduced from the optical disk 609 are read as shown in FIG. Then, the data is written in the buffer memory 105 as shown in FIG. The data written in the buffer memory 105 at the timing shown in FIG. 8C is accumulated in the buffer 105 for a certain period of time, and then the video / audio decoder from the buffer memory 105 at the timing shown in FIG. The data is read out to 104 and reproduced at the timing shown in FIG.

  With such an operation, when the chasing playback mode is set, chasing playback can be performed without causing overflow or underflow of the buffer memory. In the normal recording mode, the encoding rate can be set to a high encoding rate according to the capability of the recording medium, so that high-quality and high-quality video / audio can be obtained. In addition, since recording and playback are performed simultaneously in the chasing playback mode, simultaneous recording playback and chasing playback can be realized without the need to increase the transfer rate of the recording medium.

  Further, in the above-described embodiment, the system controller 601 has set the audio / video encoder 101 so that the encoding rate is lower than that in the normal recording mode. However, in a modified example, in the chasing playback mode, the system controller 108 sets the encoding rate to be the same as normal. However, when it is determined that the recording buffer 102 is about to overflow in the chasing playback mode, the system controller 108 forcibly lowers the encoding bit rate from the normal time by the encoder 101, and the recording buffer 102 Suppresses the possibility of overflow.

(Embodiment 3)
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 that of the simultaneous recording / reproducing apparatus in the second embodiment shown in FIG. However, the video / audio encoding device 101 performs encoding at a variable bit rate. Here, the encoding 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 equal to or lower than the 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 for a predetermined period is equal to or lower than the predetermined bit rate.

(Embodiment 4)
FIG. 9 shows a simultaneous recording / reproducing apparatus according to the fourth 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 / reproduction signal processor 107, a system controller 901, an optical disc 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 chasing reproduction by high-speed reproduction, as will be described later, when the recording buffer is about to overflow, the system controller 901 returns to normal reproduction.

  The basic operation relating to the simultaneous recording / reproducing apparatus is the same as the normal operation described in the first embodiment. FIG. 10 schematically shows temporal changes with respect to the recording / reproduction to / from the optical disk 909, writing / reading to / from the buffer memories 102 and 105, and the audio / video signals A and B in the simultaneous recording / reproducing apparatus shown in FIG. As shown in FIG. 10A, the access to the optical disk 909 is performed alternately between reading and writing. In FIG. 10A, the data indicated by hatching indicates data reproduced from the optical disk 909, and the data not indicated by hatching indicates recording on the optical disk 909.

  In FIG. 10, until the time 1001, the simultaneous recording / reproducing apparatus performs a normal simultaneous recording / reproducing (chase reproduction) operation. FIG. 11A shows the data recorded on the optical disc 909 at time 1001 and the reproduction status. FIG. 11 schematically shows the logical arrangement and reproduction status of data recorded on the optical disc 909. As shown in FIG. 11A, at time 1001, up to data o is recorded on the optical disc 909, and reproduction is performed up to data c on the already recorded data.

  Here, it is assumed that reproduction control for performing high-speed reproduction is input to the system controller 901 at time 1001. With this reproduction control, the system controller 901 reads data for high-speed reproduction from the optical disc 909. That is, after the data g is reproduced, the data k is reproduced without reproducing the data i. Also, the video / audio decoder 104 is informed that high-speed playback data is input. FIG. 11B shows the recording and reproduction status with respect to the optical disc 909 at time 1002. Thereafter, the system controller 901 performs reproduction while thinning out data recorded on the optical disk 909.

  FIG. 11C shows the recording and reproduction status with respect to the optical disc 909 at time 1003. At time 1003, the reproduction with respect to the optical disc 909 is performed up to the data t. Therefore, the data to be reproduced next is the data recorded next to the data u, but the data next to the data u is not yet recorded at the time 1003. Therefore, the system controller 901 ends the high speed reproduction operation, shifts to the normal reproduction operation, and reproduces the data u. FIG. 11D shows the recording / reproduction status with respect to the optical disc 909 at time 1004. Thereafter, the system controller 901 performs normal playback from the optical disk 906. FIG. 11E shows a recording / reproducing state with respect to the optical disc 909 at time 1005.

  The simultaneous recording / reproducing apparatus performs reproduction from the optical disc 909 without performing reproduction in the EE system even when the reproduction position catches up with the recording position. In order to perform reproduction in the EE system, reproduction may be performed using the system 902 in FIG. However, for example, when the playback control for performing backward playback is performed on the system controller 901 after the playback position catches up with the recording position and shifts to the normal playback operation, if playback is performed in the EE system, Playback from the optical disk 909 must be performed, and the operation becomes complicated. Even if the playback position catches up with the recording position, if playback is performed from the optical disc 909 without playback in the EE system, playback control for performing reverse playback is performed after the playback position catches up with the recording position and shifts to the normal playback operation. Even when it is performed on the system controller 901, it is possible to smoothly shift to the backward reproduction operation.

  As described above, the simultaneous recording / playback apparatus according to the present embodiment performs high-speed playback or the like during simultaneous recording / playback or chasing playback, and shifts from the high-speed playback operation to the normal playback operation when the playback position catches up with the recording position. The playback position should not overtake the recording position. Since the playback position does not overtake the recording position by such an operation, it is possible to prevent meaningless data from being played and disturb the video and audio.

  Further, the simultaneous recording / reproducing apparatus of this embodiment performs reproduction from the optical disc without performing reproduction in the EE system even when the reproduction position catches up with the recording position. By such an operation, after the reproduction position catches up with the recording position and shifts to the normal reproduction operation, for example, even when reproduction control for performing reverse reproduction is performed, it is possible to smoothly shift to the reverse reproduction operation.

  Further, in the present embodiment, the case where the amount of data read / written at the same time in the buffer memory and the disk is shown, but this amount of data may be different every time data is read / written. In addition, the amount of data accessed at one time in reading / writing with respect to the buffer memory and reading / writing with respect to the disk may be different. In addition, the amount of data accessed at one time when reading data and when writing data to the buffer memory or the optical disk may be different.

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

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

  In this embodiment, the case where high-speed playback is performed during chasing playback and the playback position catches up with the recording position has been described. However, even when the playback position catches up to the recording position for reasons other than high-speed playback, A recording / reproducing apparatus can be used. For example, there may be a case where the playback position catches up with the recording position because the recording operation is paused or stopped. In such a case, when the reproduction position catches up with the recording position, the reproduction operation may be shifted to a stop state or a pause state.

(Embodiment 5)
FIG. 12 shows a simultaneous recording / reproducing apparatus in the fifth embodiment of the present invention. This simultaneous recording / playback apparatus includes a video / audio encoder 101, buffer memories 102 and 105, a video / audio decoder 104, a recording / playback 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 and playback device performs high-speed playback at the time of chasing playback, and when the playback position catches up with the recording position, when the high-speed playback operation is canceled and the normal playback operation is started, the normal playback operation is confirmed. Display on the screen. By performing such an operation, the user can be notified that the high-speed operation has been automatically changed to the normal operation. The user can know why the user has shifted from the high-speed operation to the normal operation, and can provide a user-friendly user interface.

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

  In this simultaneous recording / reproducing apparatus, an operation when the reproduction position catches up with the recording position will be described. When the system controller 1201 detects that the playback 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 playback position has caught up with the recording position. When the display character generator 1202 receives the notification from the system controller 1201, it generates character data notifying that the reproduction position has caught up with the recording position, and outputs it to the video signal superimposing unit 1203. The video signal superimposing unit 1203 superimposes the video / audio signal output from the video / audio decoder 104 and the character data output from the display character generator 1202 and outputs the video / audio signal B. As an example of 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-described embodiments, the case where an optical disk is used as the recording medium has been described. However, this may be another recording medium such as a magnetic disk.

  In each of the above-described embodiments, the case where the amount of data read / written at the same time in the buffer memory and the disk has been described. However, the amount of data may be different every time data is read / written. In addition, the amount of data accessed at one time in reading / writing with respect to the buffer memory and reading / writing with respect to the disk may be different. In addition, the amount of data accessed at one time when reading data and when writing data to the buffer memory or the optical disk may be different.

  Preferably, in each of the above-described embodiments, the recorded data is guaranteed even if a power failure occurs during chasing playback. In normal operation, management information (address information, etc.) of recorded data is stored in the memory of the system controller, and after all data (for example, data for one program) has been recorded, the management data is recorded on the disk. 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 video / audio information cannot be reproduced even if it is recorded on the disc. Therefore, the management data is recorded on the disk at regular intervals to prevent the management data from being lost due to a power failure or the like. In this case, after repeating the data recording → data reproduction sequence a predetermined number of times, the management data is written into the file management area. When the video / audio information is recorded, the management data is updated. Therefore, the management data is preferably recorded after the video / audio data is recorded.

  Further, in each of the above-described embodiments, a restriction on chasing playback may be provided. For example, when the recording zone and the reproduction zone are too far apart, the seek time is increased accordingly, so that the recording buffer 102 tends to overflow and the reproduction buffer 105 tends to underflow. Therefore, the system controller 108 prohibits the chasing playback when the recording zone and the playback zone are too far apart. Even if the user inputs chasing playback, the acceptance is rejected. Specifically, for example, the zone range for performing the chasing playback zone is limited. For example, if it is determined that, for example, the recording zone and the reproduction zone are apart from each other by a certain threshold value (two zones) between zones where the seek time is equal to or longer than a predetermined time, chasing reproduction is prohibited.

(Embodiment 6)
FIG. 14 shows a simultaneous recording / reproducing apparatus according to the sixth embodiment of the present invention. This simultaneous recording / playback apparatus includes a video / audio encoder 101, buffer memories 102 and 105, a video / audio decoder 104, a recording / playback signal processor 107, a system controller 1408, an optical disc 109, a data selector 110, an optical head 1411, It consists of a motor 1412. In this simultaneous recording / reproducing apparatus, reproduction is performed from another zone while maintaining the rotation speed of the recording zone.

  Regarding the simultaneous recording / reproducing apparatus shown in FIG. 14, the operation during recording will be described first. The video / audio signal A is encoded by the video / audio encoder 101 to be an encoded sequence. For example, when the video / audio encoder 101 is an MPEG encoder, the video code sequence generated by MPEG encoding the video signal of the video / audio signal A and the audio signal of the video / audio signal A are encoded by MPEG. The audio code string generated by the AC-3 encoding is multiplexed into an MPEG system code string, which is output from the video / audio encoder 101. The code string output from the video / audio code string 101 is stored in the buffer memory 102. The code string stored in the buffer memory 102 is read by the data selector 110 and input to the recording / reproducing signal processor 107, and subjected to ECC processing and modulation processing for recording on the optical disc 109, and then the optical head 1411. To be recorded on the optical disk 109.

  Next, the operation during reproduction will be described. A signal read from the optical disk 109 via the optical head 1411 is subjected to binarization, demodulation, ECC processing, and the like by the recording / reproducing signal processor 107 to become a code string, and then buffered via the data selector 110. Input to the memory 105. The code string read from the buffer memory 105 is decoded by the video / audio decoder 104 to become a video / audio signal B.

  Switching between recording and reproduction operations is performed by a system controller 1408. The system controller controls whether to reproduce data from the optical disk 109 or to record data on the optical disk 109 depending on whether the recording operation or the reproducing operation is performed. The system controller 1408 controls the data selector 110 so that data flows from the 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. To control.

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

  First, a case where recording is performed in the zone 1501 and reproduction is performed from the zone 1502 will be described. Assume that data b, d, f, and h are recorded in areas 1520, 1521, 1522, and 1523, respectively. It is assumed that data a is recorded in area 1510. In this case, after data a is recorded in area 1510, the beginning of area 1520 is searched, and data b is reproduced from area 1520. Thereafter, the head of the area 1511 is searched, and the data c is recorded in the area 1511. Thereafter, the head of the area 1521 is searched, and the data d is reproduced from the area 1521. During this recording and reproducing operation, the rotational speed of the optical disk 109 is made constant at the rotational speed when data is recorded in the zone 1501. Therefore, even when data is reproduced from the zone 1502, the data is reproduced at the number of rotations when data is recorded in the zone 1501. This rotation control is determined by the zone in which the system controller 1408 is currently performing the recording operation, and is performed by controlling the motor 1412 so that the determined rotation speed is obtained. In the ZCLV system, the inner circumference has a higher rotational speed. In this case, playback from the zone 1502 is performed at a slower rotational speed than usual. However, the reproduction of data from the disc has a much larger margin than the recording, so that even if data is reproduced from the zone 1502 at a low rotation speed suitable for recording in the zone 1501, the reproduction can be performed correctly. .

  Next, a case where recording is performed in the zone 1502 and reproduction is performed from the zone 1501 will be described. It is assumed that data, b, d, f, and h are recorded in areas 1510, 1511, 1512, and 1513, respectively. It is assumed that data a is recorded in the area 1520. In this case, after data a is recorded in area 1520, the beginning of area 1510 is searched, and data b is reproduced from area 1510. Thereafter, the head of the area 1521 is searched, and data c is recorded in the area 1521. Thereafter, the head of the area 1511 is searched, and the data d is reproduced from the area 1511. During this recording and reproducing operation, the rotational speed of the optical disk 109 is made constant at the rotational speed when data is recorded in the zone 1502. Therefore, even when data is reproduced from the zone 1501, the data is reproduced at the rotation speed when recording data in the zone 1502. This rotation control is determined by the zone in which the system controller 1408 is currently performing the recording operation, and is performed by controlling the motor 1412 so that the determined rotation speed is obtained. In the ZCLV method, the inner circumference has a higher rotational speed. In this case, playback from the zone 1501 is performed at a rotational speed faster than usual. However, the reproduction of data from the disc has a much larger margin than the recording, so that even if the data is reproduced from the zone 1501 at a high rotation speed suitable for recording in the zone 1502, the reproduction can be performed correctly. .

  As described above, this simultaneous recording / reproducing apparatus records the video / audio signal of a certain program on a recording medium, performs the recording operation, and reproduces the video / audio signal recorded up to that point, that is, chasing playback. To do. At the time of the simultaneous recording and reproduction, the rotation speed of the optical disk is constant at a rotation speed suitable for the zone where the recording operation is performed, and reproduction is performed with the rotation speed even at the time of reproduction. Reproduction of data from a disc has a much larger margin than recording, so that data can be reproduced correctly even if data is reproduced from different zones while maintaining the rotation speed suitable for the recording zone.

  By performing such an operation, it is necessary to change the rotation speed between the recording position and the reproducing position even in the case of a ZCLV disc when moving from the recording operation to the reproducing operation or from the reproducing operation to the recording operation in simultaneous recording and reproducing. Disappear. Therefore, the time between the recording operation and the reproducing operation can be shortened, and the operation efficiency can be improved. By improving the operation efficiency, the audio / video signal can be encoded and recorded and reproduced at a high encoding rate.

  In this embodiment, the case where the optical disk 109 is recorded by the ZCLV method has been described. However, other methods may be used as long as the number of rotations is different depending on the recording position, such as the CLV method.

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

  Note that although FIG. 15 in the present embodiment shows the case where time-sequential data is recorded in a continuous area, the position where data is recorded need not be a continuous area.

  Further, in the present embodiment, the case where the amount of data read / written at the same time in the buffer memory or the disk is shown, but this data amount may be different every time the data is read / written. In addition, the amount of data accessed at one time in reading / writing with respect to the buffer memory and reading / writing with respect to the disk may be different. In addition, the amount of data accessed at one time when reading data and when writing data to the buffer memory or the optical disk may be different.

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

  In the ZCLV method, the rotation speed is faster in the inner peripheral zone. For this reason, when playback is performed from the recording zone by chasing playback, if the playback zone is on the inner circumference side, the recording rate of the zone may exceed the playback rate, and in such a case, the playback image is interrupted in the middle It will be. In order to avoid such a situation, the zone selection method for simultaneous recording / reproduction described above is preferably limited as follows. That is, recording is performed from the outer peripheral zone toward the inner peripheral zone. When a certain zone is played back by chasing playback, playback is performed at a faster rotational speed than when the zone was recorded. As a result, when a zone that is chasing playback is played back, playback is performed at a faster rotational speed than when the zone is recorded, and the playback image is not interrupted. In another method, even when the recording areas are not continuous, recording is started from the outer peripheral zone as much as possible, and recording is sequentially performed in the inner peripheral zone. In other words, the recording zone is always inside the reproduction zone. This provides the same effect. In another method, recording is performed from the inner periphery to the outer periphery according to the spiral in the zone. That is, in the zone, recording is performed from the outside to the inside. Recording is performed in a certain unit. The “certain unit” is, for example, a data amount corresponding to video / audio signals for a plurality of heads, a plurality of ECC blocks, or a predetermined time (for example, recording / reproduction switching time in chasing reproduction). Thereby, the seek time can be shortened as much as possible.

(Embodiment 7)
Next, a simultaneous recording / reproducing apparatus according to a sixth embodiment of the present invention will be described with reference to FIGS. The components of the 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 the same as that of the seventh embodiment shown in FIG. That is, when performing simultaneous recording / reproduction (chasing reproduction), the reproduction operation is performed while maintaining the number of rotations determined by the position on the recording medium on which the recording operation is performed. Here, in this simultaneous recording / reproducing apparatus, the rotation speed is optimum for the recording position where the rotation speed on the recording medium is minimum, and is equal to or less than the rate when the data of the zone where the rotation speed on the recording medium is maximum is read. The bit rate of encoding is controlled so that The differences from the simultaneous recording / reproducing apparatus of the sixth embodiment will be described below.

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

  Assume that the rotational speed of the zone 1601 that is the outermost peripheral zone is M, and the rotational speed of the zone 1605 that is the innermost peripheral zone is N. Assume that the maximum recording rate of the optical disk 109 is R. In this case, the system controller 1408 determines the encoding rate when the video / audio encoder 101 encodes the video / audio signal A to be a value smaller than the value determined by the equation (1), and the video / audio The encoder 101 performs encoding at the encoding rate determined by the system controller 1408.

  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 given an average bit rate at a certain interval. Variable bit rate encoding that satisfies the encoding rate may be used.

  As described above, the simultaneous recording / reproducing apparatus of the present embodiment records the video / audio signal of a program on a recording medium, performs the recording operation, and reproduces the video / audio signal recorded up to that point, that is, chasing. Play it. At the time of the simultaneous recording and reproduction, the rotation speed of the optical disk is constant at a rotation speed suitable for the zone where the recording operation is performed, and reproduction is performed with the rotation speed even at the time of reproduction. When performing simultaneous recording and playback, the bit rate for encoding the audio / video signal is obtained when the data of the zone with the maximum number of rotations is read using the optimal number of rotations for the zone with the minimum number of rotations. The value is less than or equal to the maximum data rate allowed.

  By performing such an operation, when the rotation speed is controlled at the minimum state, that is, when the recording operation is performed in the outermost zone, the reproduction operation must be performed in the innermost zone. Even so, the rate of the recorded data is a value that can guarantee the data rate even if the data in the innermost zone is read out with the minimum number of rotations. Real-time performance can be guaranteed.

  In this embodiment, the case where the optical disk 109 is recorded by the ZCLV method has been described. However, other methods may be used as long as the number of rotations is different depending on the recording position, such as the CLV method.

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

  Further, in the present embodiment, the case where the amount of data read / written at the same time in the buffer memory and the disk is shown, but this amount of data may be different every time data is read / written. In addition, the amount of data accessed at one time in reading / writing with respect to the buffer memory and reading / writing with respect to the disk may be different. In addition, the amount of data accessed at one time when reading data and when writing data to the buffer memory or the optical disk may be different.

  Although the chasing playback has been described in the sixth and seventh embodiments, it is desirable to make the seek time as short as possible during chasing playback in order to prevent buffer overflow and underflow. Therefore, before recording, a continuous free area as large as possible is found and data is continuously recorded in that area. As a result, data is recorded in a near zone, and seek time can be reduced.

  In the sixth and seventh embodiments, the reproduction speed is maintained at the rotation speed suitable for the zone in which the recording operation is performed, and the reproduction speed is also maintained during the reproduction. The case where chasing playback is performed has been described. Here, the recording operation also has a slight margin with respect to the rotational speed. Therefore, the rotational speed may be determined within this margin. For example, when the recording position is on the outer circumference side than the reproduction position, the reproduction operation is performed at a rotation speed slower than the original rotation speed, but the rotation speed is within the rotation speed margin determined by the recording position. By maximizing the value, the rotational speed of the reproducing operation can be slightly increased. As a result, the restriction on the encoding rate and the like at the time of chasing playback is relaxed.

(Embodiment 8)
FIG. 17 shows a multi-channel simultaneous playback apparatus according to the eighth embodiment of the present invention. As shown in FIG. 17, this multi-channel simultaneous reproduction apparatus includes a reproduction signal processor 1701, a data selector 1702, buffer memories 1703 and 1704, video / audio encoders 1705 and 1706, a system controller 1707, an optical disk 1708, and an optical head. 1709. In this multi-channel simultaneous reproduction apparatus, at the time of multi-channel simultaneous reproduction, reproduction is also performed from the outer peripheral zone in accordance with the rotation speed read from the inner peripheral zone.

  Assume that two code strings as shown in FIG. 20 are recorded on the optical disk 1708. FIG. 18 shows a logical arrangement of two code strings. FIG. 20A shows the video / audio signal C, and FIG. 20B shows the video / audio signal D.

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

  Consider a case where 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 disc 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. In FIG. 18, the same symbol is used to indicate that the same data or the same data is decoded.

  The operation of the simultaneous multi-channel playback device will be described with reference to FIGS. A signal read from the optical disk 1708 via the optical head 1709 is binarized, demodulated, ECC processed, etc. by the reproduction signal processor 1701 to become a code string, and then buffered via the data selector 1702. 1703 or 1704 is input. The code string read from the buffer memory 1703 or 1704 is decoded by a video / audio decoder 1705 or 1706 to become a video / audio signal C or D.

  Here, the data selector 1702 switches between which of the buffer memories 1703 and 1704 the code string read from the optical disk 1708 is written. The system controller 1707 reads the code string read from the optical disk 1708 in the buffer memories 1703 and 1704 depending on whether the code string of the video / audio signal C is read from the optical disk 1708 or the code string of the video / audio signal D is read from the optical disk 1708. Control which one to write to. Here, it is assumed that the code string of the video / audio signal C is written in the buffer memory 1703 and the code string of the video / audio signal D is written in the buffer memory 1704.

  As shown in FIG. 18A, the access to the optical disc 1708 is performed by alternately reading the code sequence of the video / audio signal C and the code sequence of the video / audio signal D. In FIG. 18 (a), the shaded lines indicate the reading of the code sequence of the video / audio signal D, and the unshaded lines indicate the reading of the code sequence of the video / audio signal C. For example, after the data a (part of the code string of the video / audio signal C) is reproduced in the period 701, the reproduction position of the data b is searched (period 702), and the data b (the code of the video / audio signal D is reproduced in the period 703). Play a part of the column).

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

  Here, data a, c, e, etc. are recorded in the zone 1901, and data b, d, f, etc. are recorded in the zone 1902. Therefore, the reproduction operation described above repeats the operations of data reproduction from the zone 1901, retrieval and movement from the zone 1901 to the zone 1902, data reproduction from the zone 1902, retrieval and movement from the zone 1902 to the zone 1901. It will be. During this reproduction operation, the rotational speed of the optical disk 1708 is made constant at the rotational speed when data is reproduced from the zone 1902. Therefore, even when data is reproduced from the zone 1901, data is reproduced from the zone 1902 at the number of rotations. This rotation control is performed by the system controller 1707 determining from the rotation speed at which the innermost zone of the currently reproduced zone group is reproduced, and controlling the motor 1710 so that the determined rotation speed is obtained. . In the ZCLV method, the inner circumference has a higher rotational speed, and in this case, playback from the zone 1901 is performed at a rotational speed faster than usual. However, since the reproduction of data from the disc has a very large margin, even if the data is reproduced from the zone 1901 at a high rotation speed suitable for reproduction from the zone 1902, the reproduction can be performed correctly.

  As described above, this simultaneous multi-channel playback device simultaneously plays back a code sequence of a plurality of video / audio signals in a time division manner from a recording medium on which a code sequence obtained by encoding a plurality of video / audio signals is recorded. At the time of simultaneous multi-channel reproduction, the rotation speed of the optical disk is constant at a rotation speed suitable for the inner zone, and reproduction is performed with the rotation speed even when data is reproduced from the outer zone. Since reproduction of data from the disc has a very large margin, even if data is reproduced from the outer zone, it can be reproduced correctly at a high rotation speed suitable for the inner zone.

  By performing such an operation, it is not necessary to change the number of rotations at the playback position even in the case of a ZCLV disc when shifting from the playback operation of one channel to the playback operation of another channel in simultaneous multi-channel playback. . Therefore, the time for zone movement can be shortened, and the operation efficiency can be improved. This improvement in operating efficiency makes it possible to reproduce a multi-channel code string of a video and audio signal with a high coding rate. In addition, since the speed is matched with the rotation speed of the inner peripheral zone, the data rate when reproducing the data recorded in the inner peripheral zone can be guaranteed.

  In this embodiment, the case where the optical disk 109 is recorded by the ZCLV method has been described. However, other methods may be used as long as the number of rotations is different depending on the recording position, such as the CLV method.

  In the present embodiment, the case where the track is spiral as shown in FIG. 19 has been described. However, the track need not be spiral.

  Note that FIG. 15 in the present embodiment shows a case where temporally continuous data is recorded in the same zone. However, the position where data is recorded need not be the same zone.

  Further, in the present embodiment, the case where two channels of 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 the number of rotations is controlled in accordance with the inner peripheral zone of the channels to be reproduced when data of two channels is reproduced simultaneously. However, the reproduction may be performed at the rotational speed at the time of always reproducing the innermost zone or at the rotational speed or higher. For example, when the optical disk 1708 is reproduced, the reproduction may be performed at the rotational speed for reproducing the zone 1903 or at the rotational speed or higher. Thereby, it is possible to guarantee the data rate when data is reproduced from any zone.

  In each of the above-described simultaneous recording / reproducing apparatuses, the recording operation and the reproducing operation with respect to the recording medium are preferably performed by one head (the same head). In the simultaneous multi-channel playback apparatus described above, playback on a plurality of channels is preferably performed by one head (the same head). This simplifies the configuration of the device.

  The simultaneous recording / reproducing apparatus according to the present invention records the input signal, and can reproduce the recorded signal when recording is continued. Therefore, the simultaneous recording / reproducing apparatus according to the present invention is useful for simultaneous recording / reproduction in which a video / audio signal is recorded on a recording medium and chasing reproduction is performed.

Block diagram of the simultaneous recording / reproducing apparatus in the first embodiment of the present invention Schematic diagram showing the concept of chasing playback in the first embodiment of the present invention Schematic diagram showing the flow of data in chasing playback for explaining the first embodiment of the present invention Schematic diagram showing the recording position on the optical disc in the first embodiment of the present invention Schematic diagram showing the flow of data in chasing playback for explaining the first embodiment of the present invention The block diagram of the simultaneous recording / reproducing apparatus in 2nd embodiment of this invention Schematic diagram showing the flow of data in chasing playback for explaining the second embodiment of the present invention Schematic diagram showing the flow of data in chasing playback for explaining the second embodiment of the present invention The block diagram of the simultaneous recording / reproducing apparatus in 4th embodiment of this invention Schematic diagram showing the flow of data in chasing playback for explaining the fourth embodiment of the present invention Schematic diagram showing the status of data recording and playback in chasing playback for explaining the fourth embodiment of the present invention Block diagram of the simultaneous recording / reproducing apparatus in the fifth embodiment of the present invention The schematic diagram which shows an example of the display in 5th embodiment of this invention Block diagram of the simultaneous recording / reproducing apparatus of the sixth embodiment of the present invention Schematic diagram showing the recording position on the optical disc Schematic diagram showing zone arrangement on optical disc Block diagram of the simultaneous multi-channel playback device of the eighth embodiment of the present invention Schematic diagram showing the data flow in simultaneous multi-channel playback Schematic diagram showing zone arrangement on optical disc Schematic diagram showing the structure of a code string in simultaneous multi-channel playback

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 / Reproduction Signal Processor 108, 601, 607, 901, 1202, 1408, 1707 System controller 109,609,909,1708 Optical disk 110 Data selector 1411,1709 Optical head 1412 Motor 1701 Playback signal processor 1702 Data selector 1703,1704 Buffer memory 1705,1706 Video / audio decoder

Claims (3)

Encoding means for encoding the input first signal into a first code string;
First buffer memory means for storing the first code string encoded by the encoding means;
Data recording means for recording the first code string read from the first buffer memory on a recording medium;
Data reproducing means for reading out the first code string recorded on the recording medium as a second code string for a certain time before;
Second buffer memory means for storing the second code string read by the data reproduction means;
Decoding means for reading and decoding the second code string from the second buffer memory means and outputting it as a second signal;
System control means for setting the coding rate of the first signal in the coding means,
The system control means includes
When recording the first code string, the number of rotations is changed between the inner circumference area and the outer circumference area of the recording medium, and when the second code string is reproduced, the recording area is rotated. Using the number, let the data recording means and the data reproducing means perform the recording operation and the reproducing operation on the recording medium alternately in time,
When set to the simultaneous recording / reproducing mode for simultaneously recording the first signal and reproducing the second signal,
The system control means reads out the innermost circumferential area where the rotational speed during the recording operation on the recording medium is the maximum value at the rotational speed of the outermost recording area where the rotational speed on the recording medium is the smallest. The encoding rate of the encoding means is set below the reading rate of
The encoding means encodes the first signal at the set encoding rate;
And a simultaneous recording / reproducing apparatus. The encoding rate is M for recording the outermost recording area, N for recording the innermost recording area, and R for the maximum recording rate on the recording medium. In case,
The simultaneous recording / reproducing apparatus according to claim 1, wherein the rate is smaller than R × M / N. When the system control means is set to the simultaneous recording / reproducing mode,
Detecting a continuous free area of the recording area, and then performing the recording operation on the free area;
The simultaneous recording / reproducing apparatus according to claim 1 .

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