JP2001283525A - Method and device for image recording and reproduction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that simultaneous reproduction wherein the same program is reproduced while recorded is diabled if the time difference between the recording and reproduction becomes small. SOLUTION: For the simultaneous reproduction, this method has a reproduction path selection step for selecting a 1st reproduction path for reproduction from reproduction data temporarily stored in a semiconductor memory after being read out of a disklike recording medium or a 2nd reproduction path for reproduction from recording data temporarily stored in the semiconductor memory and an AV signal reproduction step for reproducing an AV signal by reading the recording data or reproduction data out of the semiconductor memory according to the reproduction path selected in the reproduction path selection step; and the reproduction paths are changed according to the time difference between a program which is being video-recorded and a program which is being reproduced, thus the simultaneous reproduction can be performed even when the time difference becomes small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to A
The present invention relates to a disk-shaped recording medium recording / reproducing apparatus for recording / reproducing V data on a disk-shaped recording medium such as an optical disc in real time, and a disk-shaped recording medium recording / reproducing apparatus.

[0002]

2. Description of the Related Art Conventionally, recording of TV broadcast programs has been mainly performed on video tapes such as VHS. However, in recent years, disk recorders for recording digital compressed images on a disk-shaped recording medium such as an HDD or an optical disk have been developed. In particular, an optical disk recorder such as a DVD is a conventional videotape as a replaceable disk medium. It is attracting attention as a new product that replaces recorders.

A video recorder using such a disk medium has better random access than a conventional tape medium, and by making use of this characteristic, a simultaneous reproduction that simultaneously records and reproduces a program on a disk. Functions are becoming possible as new additional functions.

That is, a recording operation of a program on a disk and a reproducing operation of reproducing another program already recorded on the disk or a recorded portion of the same program from the disk are executed at high speed in a time-division manner by utilizing a high-speed access function. By doing so, apparently simultaneous recording and reproduction becomes possible.

For example, in a DVD recorder, the recording rate of MPEG-compressed video is about 10 Mbps at maximum, and 10 Mbps necessary for simultaneous recording and reproduction.
× 2 = recording / reproducing on a disk medium at a speed of 20 Mbps or more is possible, and recording / reproducing once is several hundred K
Bytes to several Mbytes or more, each of which is tens
This can be realized by providing a large-capacity buffer memory capable of alternately repeating a high-speed access of about 0 ms to 1 second, and absorbing an operation stoppage caused by time division of recording or reproduction.

In addition to simply playing back the recorded portion of the program being recorded, at this time, the time difference between the recording and the playback is gradually reduced by using special playback such as fast-forward playback or CM skipping. So-called chase reproduction, which is shrinking, becomes possible.

[0007]

However, if the simultaneous reproduction function described above is performed only by the high-speed access function which is a characteristic of the disc and the time division execution of recording / reproduction at twice or more speed, the time difference between recording and reproduction is small. In some cases, it could not be executed at the same time.

If the time difference between recording and reproduction is less than the time obtained by adding the access time and the overhead time via the buffer for the time division operation, that is, about 10 seconds or less, simultaneous execution of recording and reproduction cannot be performed. There is a problem, for example, when performing chasing playback, when the playback gradually catches up with the recording and becomes less than 10 seconds,
Thereafter, there was no alternative but to continue watching with the time difference or suddenly switch to the time difference 0, that is, to simply watch the TV broadcast (in this case, the video of 10 seconds or less is missed).

[0009] The existence of such an inoperable time when the time difference between recording and reproduction is reduced depends on how the viewer perceives and the content of the program being viewed. However, for a new AV device such as an optical disk recorder, After all, it was an issue to be avoided.

In view of the above problems, the present invention can realize simultaneous reproduction even when the time difference between recording and reproduction is small. In the case of chase reproduction, finally, the time difference between recording and reproduction becomes zero. It is an object of the present invention to provide an image recording / reproducing method and an image recording / reproducing apparatus capable of continuously catching up to the following.

[0011]

According to the present invention, there is provided an image recording / reproducing method according to the present invention, wherein, at the time of recording, a recording data storing step of temporarily storing recording data in a semiconductor memory; A recording step for recording on a recording medium, a reproduction data storage step for temporarily storing reproduction data reproduced from the disc-shaped recording medium in the semiconductor memory, and a reproduction data storage step for reading from the disc-shaped recording medium during reproduction. Then, a first reproduction path for performing reproduction from the reproduction data temporarily stored in the semiconductor memory is selected, or a second reproduction path for performing reproduction from the recording data temporarily stored in the semiconductor memory in the recording data storing step is selected. A reproduction path selection step of determining whether to select or not, and according to the reproduction path selected in the reproduction path selection step. The semiconductor memory reads the recording data or reproducing data is obtained by a AV signal regeneration step of reproducing the AV signal.

[0012] The image recording / reproducing apparatus of the present invention, when recording,
Recording data storage means for temporarily storing recording data in a semiconductor memory; recording means for recording recording data temporarily stored in the semiconductor memory on a disc-shaped recording medium; and reproduction data reproduced from the disc-shaped recording medium. A reproduction data storage means for temporarily storing the data in a memory, and a first reproduction path for performing reproduction from the reproduction data read from the disc-shaped recording medium and temporarily stored in the semiconductor memory by the reproduction data storage means during reproduction. Or a second reproduction path for performing reproduction from the recording data temporarily stored in the semiconductor memory by the recording data storage means, and a reproduction path selection means for determining the reproduction path selection means. An AV signal reproduction for reading the recording data or the reproduction data from the semiconductor memory and reproducing the AV signal according to a reproduction path. It is obtained by a means.

According to the image recording / reproducing method of the present invention, when recording,
A recording data storing step of temporarily storing recording data in a semiconductor memory; a recording step of recording the recording data temporarily stored in the semiconductor memory on a disc-shaped recording medium; and a reproduction data reproduced from the disc-shaped recording medium. A reproduction data storage step for temporarily storing the data in a memory, and a first reproduction path for performing reproduction from the reproduction data read from the disk-shaped recording medium and temporarily stored in the semiconductor memory in the reproduction data storage step during reproduction. Or a second reproduction path for performing reproduction from the recording data temporarily stored in the semiconductor memory in the recording data storing step, or a third reproduction for performing reproduction from the recording data before being stored in the semiconductor memory. A reproduction path selection step of determining whether to select a path, and a reproduction path selection step. In accordance with the reproduction route of the recorded data or reading out the playback data from the semiconductor memory are those with a AV signal regeneration step of reproducing the AV signal.

The image recording / reproducing apparatus according to the present invention, when recording,
Recording data storage means for temporarily storing recording data in a semiconductor memory; recording means for recording recording data temporarily stored in the semiconductor memory on a disc-shaped recording medium; and reproduction data reproduced from the disc-shaped recording medium. A reproduction data storage means for temporarily storing the data in a memory, and a first reproduction path for performing reproduction from the reproduction data read from the disc-shaped recording medium and temporarily stored in the semiconductor memory by the reproduction data storage means during reproduction. Or a second reproduction path for performing reproduction from the recording data temporarily stored in the semiconductor memory by the recording data storage means, or a third reproduction for performing reproduction from the recording data before being stored in the semiconductor memory. A reproduction path selecting means for determining whether to select a path, and the half-track according to the reproduction path selected by the reproduction path selecting means. Is obtained by a AV signal reproducing means for reproducing the AV signals from the body memory reads the recording data or reproducing data.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of an optical disk recorder according to an embodiment of the present invention. In FIG. 1, 101 is an optical disk, 102 is an optical head composed of a semiconductor laser and an optical element, 103 is a recording / reproducing circuit that performs laser control and binarizes a reproduction signal 117, and 104 records encoded data 120. Digitally modulated to generate modulated data 118 and binarized data 119
A demodulation circuit 105 digitally demodulates the data to generate demodulated data 121. Numeral 105 denotes a corrected data 123 obtained by performing error detection and correction of an error caused by a scratch or dust on the medium and removing the error.
And an error detection and correction circuit for performing error detection and correction encoding of the recording data 122, a work RAM 106 for working the error detection and correction circuit 105, a semiconductor memory 108, and the recording data 122 and the reproduction data 1
Buffer RAM used as 25 data buffers, 1
07, a buffer control circuit for controlling recording and reproduction of the buffer RAM; 109, an MPEG encoding circuit for compressing digital AV data 126 to generate compressed AV data 124;
110 is a tuner for receiving and digitizing TV broadcasts /
The AD circuit 112 expands the MPEG-compressed playback data 125 to generate playback AV data 128.
An EG decoding circuit 111 is a DA circuit for converting the reproduced AV data 128 into an analog signal to generate a video or audio AV signal 129, and a control CPU 113 for controlling the entire optical disk recorder.

In the optical disk recorder of the present embodiment configured as described above, when data is reproduced from the optical disk 101, data recorded on the optical disk 101 is read from the semiconductor laser irradiated from the optical head 102. The reflected light of the laser beam is converted into an analog signal, amplified, and binarized by the recording / reproducing circuit 103, and sent to the modulation / demodulation circuit 104 as digitized binary data 119.

In the modulation / demodulation circuit 104, when recording,
Digitally demodulates a digitally modulated signal such as modulation.
The demodulated data 121 digitally demodulated is sent to the error detection and correction circuit 105, and the WORK RAM 106 is used to perform error detection and correction processing for errors caused by scratches and dust on the medium. The error detection and correction processing is executed by, for example, decoding a known Reed-Solomon code or the like.

Corrected data 123 subjected to error detection and correction processing
Is a buffer RAM via the buffer control circuit 107.
108. The correction data 123 stored in the buffer RAM 108 is sent out to the MPEG decoding circuit 112 as reproduction data 125, and decompression processing is performed.
The expanded playback AV data 128 is sent to the DA circuit 111, converted into an analog signal, and sent as an AV signal 129 to a higher-level device such as a TV or an audio device.

On the other hand, when data is recorded on the optical disc 101, an antenna input for TV broadcast or the like is input to the tuner / A.
Digital A input to the D circuit 110 and digitized
The data is input to the MPEG encoding circuit 109 as V data 126. MPEG encoding circuit 109 converts input data to MPEG
The encoded compressed AV data 124 is generated. The compressed AV data 124 is stored in the buffer RAM 108 via the buffer control circuit 107.

The compression A stored in the buffer RAM 108
The V data 124 is sent to the error detection and correction circuit 105 as recording data 122, subjected to error detection and correction coding, and sent to the modulation and demodulation circuit 104 as encoded data 120.
The modulation / demodulation circuit 104 performs digital modulation such as 8/10 modulation and sends the modulated data 118 to the recording / reproducing circuit 103. The recording / reproducing circuit 103 performs power modulation of the semiconductor laser based on the modulation data 118, and
01 is recorded. The overall control of the recording or reproduction described above is controlled by the control CPU 113.

FIGS. 2 and 6 show the flow of recording / reproducing data in the case of performing simultaneous reproduction in which reproduction is performed simultaneously with execution of recording according to the embodiment of the present invention. FIG.

FIG. 2 shows an AV signal being recorded and an AV signal being reproduced.
FIG. 7 is a schematic diagram of a data flow when a time difference between signals is equal to or longer than a predetermined time. 2, reference numeral 201 denotes a flow of storing compressed AV data in the buffer RAM. In FIG. 1, a flow of data at the time of recording, that is, a tuner / AD circuit 110, an MPEG encoding circuit 109,
Buffer RAM 10 via buffer control circuit 107
8 shows a data flow until the data is stored as compressed AV data.

Reference numeral 202 denotes a flow of data in which the compressed AV data stored in the buffer RAM 108 is recorded on the optical disc 101.
The optical disk 1 is transmitted via an error detection / correction circuit 105, a modulation / demodulation circuit 104, a recording / reproduction circuit 103, and an optical head 102.
01 is recorded.

On the other hand, reproduction of the AV signal is performed by simultaneously executing reproduction from an area different from the area on the optical disc 101 where the AV signal is currently recorded.

Reference numeral 203 denotes a flow in which a reproduction signal reproduced from the optical disk 101 is stored as correction data in the buffer RAM 108. The optical head 102, recording / reproduction circuit 103, modulation / demodulation circuit 104, error detection / correction circuit 105, buffer The data is stored in the buffer RAM 108 as correction data via the control circuit 107.

Reference numeral 204 denotes a flow in which the corrected data stored in the buffer RAM 108 is reproduced as an AV signal, and is reproduced as an AV signal via the buffer control circuit 107, the MPEG decoding circuit 112, and the DA circuit 111. .

As described above, when the time difference between the program being recorded and the program being reproduced is equal to or longer than the predetermined time, the optical disc 10
Recording and reproduction are respectively performed for 1 and as a result, 2
As shown in FIG. 05, the recording data and the reproduction data are folded back on the optical disk 101.

The recording 202 on the disk and the reproduction 203 from the disk are not performed simultaneously but are performed in a time-division manner. At this time, it is needless to say that the transfer rate on the recording and reproducing medium needs to be at least twice the storage rate of the compressed AV data in the buffer RAM. For example, the storage rate of the compressed AV data in the buffer RAM is 10 Mbps at maximum. , The transfer speed of recording and playback is at least 2
0 or more Mbps is required.

Further, when recording and reproduction are executed in a time-division manner, one recording or reproduction is performed at a time by several Mbytes at a time, so that an overhead time for a search and a rotation waiting which occurs when switching between recording and reproduction is reduced. Can be absorbed.

FIG. 3 shows an optical disk 10 as shown in FIG.
6 is a timing chart of a process for an optical disc in a case where simultaneous recording and reproduction are performed by performing recording and reproduction with respect to No. 1 respectively.

In FIG. 3, reference numerals 301 and 305 denote recording areas on a disk (202 in FIG. 2), 303 denotes reproduction from a disk (203 in FIG. 2), and 302 and 304 denote recording areas for recording when switching between recording and reproduction. And the overhead for accessing the playback area for playback.
It mainly consists of search time and rotation waiting time. FIG. 4 is a diagram for explaining the movement of the optical head on the optical disk at this time.

In FIGS. 3 and 4, first, (301) recording on the disk (202 in FIG. 2) is performed for 10 Mbytes. Here, assuming that the transfer speed of recording or reproduction on the disk is 20 Mbps, recording takes about 4 seconds.

Next, (302) a search for a reproduction area and a rotation wait occur for one second, and (303) reproduction from the disk (203 in FIG. 2) is performed by 10 Mbytes, and 4
It takes about a second.

Next, (304) a search to the recording area and a rotation wait occur for one second, and (305) a recording (202 in FIG. 2) on the disk is performed by 10 Mbytes, and 4 seconds are recorded.
It takes about a second.

In this order, recording and reproduction are executed in a time-division manner by 10 Mbytes.

Here, recording is performed in units of 10 Mbytes.
Although the reproduction is executed in a time-sharing manner, it goes without saying that the reproduction can be changed according to the capacity of the buffer RAM 108.

FIG. 5 is an area diagram showing the contents of the buffer RAM 108 when performing simultaneous recording and reproduction by performing recording and reproduction on the optical disk 101 shown in FIGS. 2 to 4, respectively.

In FIG. 5, reference numeral 501 denotes a recording buffer area for recording, 502 denotes a reproduction buffer area for reproduction, and 507 and 508 return to the head of the area after using the last of each area. This shows a state of use as a buffer.

In the recording buffer area 501, compressed AV data 201 is sequentially stored. Stored compression A
When the V data becomes 10 Mbytes or more, the data is read out from the recording buffer area as recording data, and recorded on the disk.
2 is executed. In FIG. 5, reference numeral 504 denotes compressed AV data that has been stored in the recording buffer area 501 but has not been recorded yet but has a size of 10 Mbytes or less, that is, recorded data that has not been recorded. Reference numeral 503 denotes recording data that has already been recorded, and new compressed AV data 20 is stored.
1 is sequentially overwritten. Recording buffer area 50
By controlling the recording data 504 that has not been recorded as much as possible, it is possible to reduce the occurrence of buffer overflow when the recording time is extended by retry processing or the like that occurs when recording to a disk. become.

As described above, in the recording buffer area 501, the temporary storage and reading of the recording data are used while circulating through the ring buffer.

Similarly, the reproduction buffer area 502 stores the data 203 reproduced from the disk and is read out from the buffer as the reproduction 204 of the AV signal. Reference numeral 506 denotes data before reproduction, which is reproduced from the disk and stored in the reproduction buffer area 502, but not yet reproduced as an AV signal. Reference numeral 505 denotes data that has already been read from the buffer RAM and has been reproduced as an AV signal, and is sequentially overwritten by the reproduction data 203 from the disk newly reproduced from the disk.

As described above, in the reproduction buffer area 502, the temporary storage and reading of the reproduction data are used while circulating through the ring buffer. Reproduction buffer area 501
By controlling the amount of data 506 before reproduction as much as possible, it is possible to reduce the occurrence of buffer underflow when the reproduction time is extended by retry processing or the like that occurs during reproduction to a disk. Become.

In the present embodiment, the recording buffer area 501 and the reproduction buffer area 502 each have a capacity of at least about twice as large as a unit for recording or reproducing data on a disk in units of 10 Mbytes. Become. In addition, the larger the capacity, the more it can be used as a margin for avoiding buffer overflow or underflow when an error or a retry process suddenly occurs during recording or reproduction.

In the present embodiment, one record or reproduction on the disk is set to 10 Mbytes. However, by setting this to a small value, the capacity of the recording buffer area 501 and the reproduction buffer area 502 can be reduced. It is clear that is possible.

As described above with reference to FIGS. 2 to 5, when the time difference between the AV signal being recorded and the AV signal being reproduced is equal to or longer than a predetermined time, recording and reproduction are performed on the optical disk 101, respectively. Thus, simultaneous recording and reproduction can be performed.

Next, the operation when the time difference between the AV signal being recorded and the AV signal being reproduced is less than a predetermined time will be described.

When the time difference between the AV signal being recorded and the AV signal being reproduced becomes small, the method of recording and reproducing on the optical disk 101, as shown in FIGS. Will be difficult to perform. In the present embodiment, recording and reproduction are performed once in units of 10 Mbytes. At this time, about 4 seconds are required for each processing. It is impossible to set the time difference between the AV signal being recorded and the AV signal being reproduced in less than 5 seconds, which is about 2 seconds. For example, in FIG. 3, once recording 301 on the disk is started, reproduction 303 from the disk is started.
It took 5 seconds to start, and it was difficult to reduce it to less than this.

Therefore, in the present embodiment, the AV
When the time difference between the signal and the AV signal being reproduced becomes smaller, the reproduction of the re-AV signal is switched to a reproduction path in which the recording data stored in the buffer RAM 108 is turned back and reproduced as an AV signal.

FIG. 6 shows an AV signal being recorded and an AV signal being reproduced.
FIG. 9 is a schematic diagram of a data flow when a time difference between signals is less than a predetermined time.

In FIG. 6, reference numeral 601 denotes a flow of storing compressed AV data in the buffer RAM. In FIG. 1, the flow of data at the time of recording, that is, from the antenna input, the tuner / AD circuit 110, the MPEG encoding circuit 109,
Buffer RAM 10 via buffer control circuit 107
8 shows a data flow until the data is stored as compressed AV data.

Reference numeral 602 denotes a data flow in which the compressed AV data stored in the buffer RAM 108 is recorded on the optical disk 101.
The optical disk 1 is transmitted via an error detection / correction circuit 105, a modulation / demodulation circuit 104, a recording / reproduction circuit 103, and an optical head 102.
01 is recorded.

On the other hand, the reproduction of the AV signal
The data temporarily stored in the buffer RAM 108 is recorded on the optical disc 101 for recording the data 1, and the AV signal is reproduced by reading back the data (205) on the buffer RAM 101 as reproduction data.

Reference numeral 603 denotes a flow in which the compressed AV data stored in the buffer RAM 108 is reproduced as an AV signal, and is reproduced as an AV signal via the buffer control circuit 107, the MPEG decoding circuit 112, and the DA circuit 111. You.

As described above, when the time difference between the program being recorded and the program being reproduced is less than the predetermined time, the optical disc 10
No. 1, only recording is performed, and reproduction is performed using buffer RA.
The compressed AV data stored in M108 is reproduced.

FIG. 7 shows an optical disk 10 as shown in FIG.
1 for recording only, and for playback in buffer RAM
108 when reproducing the compressed AV data stored in
6 is a timing chart of a process for an optical disc.

In FIG. 7, reference numerals 701 and 703 denote recording on a disk (602 in FIG. 6), and reference numeral 702 denotes a rotation wait occurring between one recording and the next recording. FIG. 8 is a diagram for explaining the movement of the optical head on the optical disk at this time.

In FIGS. 7 and 8, first, (M) recording on the disk (701) (602 in FIG. 2) is performed by 10 Mbytes.

(702) Since the transfer speed of recording on the disk is twice or more higher than the speed of the compressed AV data, a rotation wait occurs next.

(703) The next 10 Mbytes of data are recorded on the disk. In this order, recording is executed in bursts of 10 Mbytes.

It should be noted that here, recording is performed in units of 10 Mbytes, but it goes without saying that it can be changed according to the capacity of the buffer RAM 108.

FIG. 9 shows a case where only recording is performed on the optical disk 101 shown in FIGS.
FIG. 4 is an area diagram showing the contents of a buffer RAM when simultaneous playback is performed by playing back compressed AV data stored in M108.

In FIG. 9, reference numeral 901 denotes a recording / reproducing buffer area for recording and reproduction, and reference numeral 905 denotes a state in which after the end of the area is used, the area returns to the head of the area and is used as a ring buffer.

In the recording / reproducing buffer area 901, compressed AV data 601 is sequentially stored. When the stored compressed AV data becomes 10 Mbytes or more, the data is read out from the recording / reproduction buffer area as recording data, and recording 602 on the disk is executed. In FIG. 9, 904 is stored in the recording buffer area 901, but the compressed AV data of 10 Mbytes or less that has not been recorded yet and has not been reproduced yet.
Data, that is, unrecorded / unreproduced recorded data is shown. Reference numeral 903 denotes recorded data that has already been recorded and has not been reproduced, and is held in a buffer until reproduction is completed. By reading the compressed AV data from the recording / playback buffer 901, playback 603 of the AV signal is realized.

The sum of the recorded data 903 before and after the recording and the unrecorded / unreproduced recording data 904 is data corresponding to the time difference between the program being recorded and the program being reproduced. Note that the reproduction 603 of the AV signal and the recording 60 on the disc are performed.
2 are controlled independently of each other, and the order is not irrelevant. When the reproduction of the AV signal 603 and the storage of the compressed AV data in the buffer RAM are close to each other, the time difference between the program being recorded and the program being reproduced is reduced. It becomes possible to make it smaller.

Reference numeral 902 denotes recorded / reproduced recording data, which is sequentially overwritten by new compressed AV data 601. By controlling the recording / reproducing buffer area 901 so that unrecorded recording data is not stored as much as possible, it is possible to reduce the occurrence of buffer overflow when the recording time is extended due to retry processing or the like that occurs during recording on a disk. It becomes possible.

The recording / reproduction buffer area 90 shown in FIG.
It is obvious that 1 does not need to have the recording buffer area 501 and the reproduction buffer area 502 shown in FIG. 5 separately, and can be shared by only changing the control method.

As described above with reference to FIGS. 6 to 9, when the time difference between the AV signal being recorded and the AV signal being reproduced is less than a predetermined time, only recording is performed on the optical disk 101 and reproduction is performed. By reproducing the compressed AV data stored in the buffer RAM 108, it becomes possible to execute simultaneous reproduction in which reproduction is performed simultaneously with recording.

As described above, in the optical disk recorder of the present embodiment, when performing simultaneous reproduction, the reproduction path of the AV signal is read out from the optical disk as reproduction data, or the compressed AV data in the buffer RAM is read out. Simultaneous reproduction is realized by switching between two paths for reproducing data according to the time difference between the AV signal being recorded and the AV signal being reproduced.

Next, the selection of these two routes will be described with reference to FIG. FIG. 10 is a timing chart showing an operation example in the case where a 60-minute program is recorded and the reproduction is started simultaneously from 15 minutes after the recording is started.

In FIG. 10, the horizontal axis indicates the elapsed time from the start of recording, the vertical axis indicates the location where the recording or reproduction is currently being performed, and the time from the beginning of the program, and 1001 indicates the recording of the program. , Starting at 0 minutes on the horizontal axis and 0 minutes on the vertical axis, and ending at 60 minutes on the horizontal axis and 60 minutes on the vertical axis.

[0092] In a step 1002, the reproduction is started 15 minutes after the start of the recording. Playback is performed at double speed from the start of playback until catching up with the program being recorded. After catching up with the recording, 1003 continuously reproduces the program being recorded.

Reference numerals 1004 and 1005 denote the time difference between the program being recorded and the program being reproduced. 1004 is a predetermined time difference of 5 seconds or more, and 1005 is less than 5 seconds.

When performing the above simultaneous reproduction, 1006
Let's just record. In 1007, since the program being recorded and the program being played back have a predetermined time difference or more, (1007)
4) At the time of simultaneous reproduction, a reproduction path of an AV signal which is read from an optical disk and used as reproduction data is selected.

Further, in 1008, since the program being recorded and the program being reproduced are less than a predetermined time difference, (1008)
5) As a reproduction path of the AV signal, a path for reading the compressed AV data in the buffer RAM and setting it as reproduction data is selected. The selection of the reproduction path is performed by the control CPU 1 shown in FIG.
13 by the reproduction control selection unit 116.

FIG. 11 is a flowchart of the reproduction control selection section 116 of the control CPU 113 when the above-described reproduction path is selected.

In FIG. 11, reference numeral 1101 calculates the time difference between the program being recorded and the program being reproduced. At present, which part of the program is being recorded or reproduced can be obtained from time measurement from the start time of recording or reproduction, or management information such as a file system generated at the time of recording. 1102
Determines whether the time difference is equal to or longer than the predetermined time of 5 seconds. If the time is equal to or longer than the predetermined time, 1103 reads a reproduction path for simultaneous reproduction from the optical disk and selects a return path on the disk to be used as reproduction data. 1105 controls the subsequent recording and reproduction based on the selected path.

On the other hand, if the time is less than the predetermined time, 1104
For the reproduction path of the AV signal, a return path in the buffer RAM is selected in which the compressed AV data in the buffer RAM is read and used as reproduction data. 1106 controls the subsequent recording and reproduction based on the selected path.

As described above, as shown in FIGS. 10 and 11, whether the time difference between the program being recorded and the program being reproduced is equal to or longer than a predetermined time (here, 5 seconds), and the AV signal during simultaneous reproduction is determined. By selecting the reproduction path of, the simultaneous reproduction can be performed regardless of the time difference between the program being recorded and the program being reproduced.

The predetermined time difference in the above example can be arbitrarily set as long as the time required for one recording or reproduction and the overhead time for switching are added. If you increase
The margin for retry occurrence due to a sudden error increases.

In the above embodiment, the reproduction path is selected based on the time difference between the program being recorded and the program being reproduced. However, it is apparent that the selection may be made based on the data amount according to the time difference. For example, for 5 seconds in the present embodiment, the transfer speed of recording and reproduction on the disc is set to 20 Mbps.
Then, the playback path becomes 100 Mbits, and the playback path is selected according to whether the data difference between the program being recorded and the program being played back is 100 Mbit or more.

Further, in the present embodiment, the reproduction path of the AV signal is selected from two paths, that is, a path for reading out from the optical disk and setting it as reproduction data, and a path for reading out the compressed AV data in the buffer RAM and setting it as reproduction data. Further, it is also possible to provide a third path that loops back before being stored in the buffer RAM 108 in FIG. That is, in FIG. 1, a path for returning the digital AV data 126 before being compressed by the MPEG encoding circuit 109 to the DA circuit 111 or a path for returning the output of the MPEG encoding circuit 109 directly to the MPEG decoding circuit 112 is added. Thus, the delay in storing data in the buffer RAM can be eliminated, and the time difference between the program being recorded and the program being reproduced can be further reduced.

In the above-described embodiment, the simultaneous reproduction is described as an example of recording and reproduction of the same program. However, when recording and reproduction are different programs, the time difference is simply considered to be very large. It is clear that simultaneous playback is possible.

As described above, according to the optical disk recorder of the embodiment of the present invention, the reproduction path of the AV signal at the time of simultaneous reproduction is selected according to the time difference between the program being recorded and the program being reproduced. Simultaneous reproduction can be performed regardless of the time difference between the program being recorded and the program being reproduced.

In the above embodiment, the optical disk recorder has been described. However, the present invention can be similarly applied to an AV recorder using a disk-shaped recording medium (disk medium) such as a hard disk (HDD).

[0086]

As described above, according to the present invention, by selecting the reproduction path of the AV signal during simultaneous reproduction according to the time difference between the program being recorded and the program being reproduced, the program being recorded and the program being reproduced are selected. Simultaneous reproduction can be performed regardless of the time difference between programs.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical disc recorder according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a data flow when a time difference between an AV signal being recorded and an AV signal being reproduced is equal to or longer than a predetermined time;

FIG. 3 is a timing chart of a process for an optical disc;

FIG. 4 is a diagram for explaining the movement of an optical head on an optical disk.

FIG. 5 is an area diagram showing contents of a buffer RAM 108;

FIG. 6 is a schematic diagram of a data flow when a time difference between an AV signal being recorded and an AV signal being reproduced is shorter than a predetermined time;

FIG. 7 is a timing chart of a process for an optical disc;

FIG. 8 is a diagram illustrating the movement of an optical head on an optical disk.

FIG. 9 is an area diagram showing contents of a buffer RAM 108;

FIG. 10 is a timing chart showing an operation example.

FIG. 11 is a flowchart of a reproduction control selection unit 116;

[Explanation of symbols]

Reference Signs List 101 optical disk 107 buffer control circuit 108 buffer RAM 116 reproduction control selection unit 201, 601 storage of compressed AV data in buffer RAM 202, 602 recording on disk 203 reproduction from disk 204, 603 reproduction of AV signal 501 recording buffer area 502 Reproduction buffer area 901 Recording / reproduction buffer area 1004, 1005 Time difference between program being recorded and program being reproduced

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/937 H04N 5/93 C (72) Inventor Tang Kitaura 1006 Kazuma, Kazuma, Osaka Prefecture Matsushita Electric Industrial F term (for reference) 5C052 AA03 AB02 AC05 CC11 CC12 DD04 5C053 FA24 FA27 GA11 GB15 GB37 HA24 HA33 KA04 5D044 AB05 AB07 BC06 CC04 EF03 EF06 FG10 FG24 GK08 GK11 HL11

Claims (14)

[Claims] 1. An image recording and reproducing method for recording an AV signal such as a TV program on a disk-shaped recording medium as digital data and simultaneously reproducing the program currently being recorded. A recording data storing step of temporarily storing the data in a memory; a recording step of recording the recording data temporarily stored in the semiconductor memory on a disc-shaped recording medium; and a temporarily storing reproduced data reproduced from the disc-shaped recording medium in the semiconductor memory. Selecting a first reproduction path for performing reproduction from the reproduction data read from the disk-shaped recording medium and temporarily stored in the semiconductor memory in the reproduction data storage step during reproduction; Selecting a second reproduction path for performing reproduction from the recording data temporarily stored in the semiconductor memory in the recording data storing step, And a AV signal reproducing step of reading the recording data or the reproduction data from the semiconductor memory and reproducing an AV signal according to the reproduction path selected in the reproduction path selection step. Image recording and reproducing method. 2. The image recording / reproducing method according to claim 1, wherein in the recording step and the reproduction data storing step, recording or reproduction is performed on the disc-shaped recording medium at a transfer speed twice or more that of the recording data. 3. The reproduction path selecting step includes selecting the first reproduction path when the time difference between the AV signal being recorded and the AV signal being reproduced is equal to or longer than a predetermined time, and selecting the first reproduction path when the time difference is shorter than the predetermined time. 2. The image recording / reproducing method according to claim 1, wherein the second reproduction path is selected. 4. The image recording apparatus according to claim 3, wherein the predetermined time is a time obtained by adding a time required for one recording or reproduction and a time for switching from recording to reproduction or from reproduction to recording. Playback method. 5. The reproduction path selecting step includes the step of: selecting the first reproduction path when the data difference between the AV signal being recorded and the AV signal being reproduced is greater than or equal to a predetermined amount; 2. The image recording / reproducing method according to claim 1, wherein the selecting step selects the second reproduction path. 6. The data processing apparatus according to claim 5, wherein the predetermined amount is equal to or greater than a sum of a data amount for one recording or reproduction and a data amount corresponding to a time for switching from recording to reproduction or from reproduction to recording. The image recording / reproducing method described in the above. 7. An image recording / reproducing apparatus for recording an AV signal such as a TV program on a disk-shaped recording medium as digital data and simultaneously reproducing the program currently being recorded. Recording data storage means for temporarily storing the data in a memory; recording means for recording the recording data temporarily stored in the semiconductor memory on a disc-shaped recording medium; and temporarily storing reproduction data reproduced from the disc-shaped recording medium in the semiconductor memory. A reproduction data storage means for performing the reproduction from the reproduction data read from the disc-shaped recording medium by the reproduction data storage means and temporarily stored in the semiconductor memory; A reproduction path selection for determining whether to select a second reproduction path for performing reproduction from the recording data temporarily stored in the semiconductor memory by the recording data storage means. Image recording / reproducing means, comprising: selecting means; and AV signal reproducing means for reading out the recording data or the reproducing data from the semiconductor memory and reproducing an AV signal in accordance with the reproducing path selected by the reproducing path selecting means. apparatus. 8. The image recording / reproducing apparatus according to claim 7, wherein the recording means and the reproduction data storage means record or reproduce the data on or from the disc-shaped recording medium at a transfer speed twice or more that of the recording data. 9. The reproduction path selection means selects the first reproduction path when the time difference between the AV signal being recorded and the AV signal being reproduced is longer than a predetermined time, and when the time difference is shorter than the predetermined time, The image recording / reproducing apparatus according to claim 7, wherein the second reproducing path is selected. 10. The image recording apparatus according to claim 9, wherein the predetermined time is equal to or longer than a time obtained by adding a time required for one recording or reproduction and a time for switching from recording to reproduction or from reproduction to recording. Playback device. 11. A reproduction path selecting means selects the first reproduction path when the data difference between the AV signal being recorded and the AV signal being reproduced is equal to or greater than a predetermined amount, and selects the first reproduction path when the data difference is smaller than the predetermined amount. The image recording / reproducing apparatus according to claim 7, wherein the device selects the second reproducing path. 12. The data processing method according to claim 11, wherein the predetermined amount is equal to or greater than a data amount for one recording or reproduction and a data amount corresponding to a time for switching from recording to reproduction or from reproduction to recording. The image recording / reproducing apparatus according to the above. 13. An image recording / reproducing method for recording an AV signal such as a TV program on a disk-shaped recording medium as digital data and simultaneously reproducing the program currently being recorded. A recording data storing step of temporarily storing the data in a memory; a recording step of recording the recording data temporarily stored in the semiconductor memory on a disc-shaped recording medium; and a temporarily storing reproduced data reproduced from the disc-shaped recording medium in the semiconductor memory. Selecting a first reproduction path for performing reproduction from the reproduction data read from the disk-shaped recording medium and temporarily stored in the semiconductor memory in the reproduction data storage step during reproduction; Whether to select a second reproduction path for performing reproduction from the recording data temporarily stored in the semiconductor memory in the recording data storing step Or a reproduction path selecting step of determining whether to select a third path for performing reproduction from the recording data before being stored in the semiconductor memory, and the semiconductor memory according to the reproduction path selected in the reproduction path selecting step. An AV signal reproducing step of reading out the recording data or reproduction data from the device and reproducing an AV signal. 14. An image recording / reproducing apparatus for recording an AV signal such as a TV program on a disk-shaped recording medium as digital data and simultaneously reproducing the program currently being recorded. Recording data storage means for temporarily storing the data in a memory; recording means for recording the recording data temporarily stored in the semiconductor memory on a disk-shaped recording medium; and temporarily storing reproduction data reproduced from the disk-shaped recording medium in the semiconductor memory. A reproduction data storage means for performing the reproduction from the reproduction data read from the disc-shaped recording medium by the reproduction data storage means and temporarily stored in the semiconductor memory; A second reproduction path for performing reproduction from the recording data temporarily stored in the semiconductor memory by the recording data storage means; A reproduction path selection unit for determining whether to select a third path for performing reproduction from the recording data before being stored in the memory, and the recording data from the semiconductor memory according to the reproduction path selected by the reproduction path selection unit. Alternatively, an image recording / reproducing apparatus comprising: AV signal reproducing means for reading reproduction data and reproducing an AV signal.