JP4258533B2 - Recording / reproducing method and recording / reproducing apparatus - Google Patents

Description

  The present invention relates to a digital recording / reproducing apparatus for video signals and audio signals for TV broadcasts, and more particularly to a time shift function.

As a conventional technique for recording and reproducing TV broadcasting and the like, there is a VTR. A tape medium can be cited as a low-cost medium for video and audio, but is structurally unsuitable for random access.
Further, techniques of Patent Documents 1 and 2 below are known.
JP-A-6-290538 JP-A-7-111629

  In order to reproduce a program recorded by a VTR, it was necessary to rewind the tape to the beginning of the program. Therefore, it is difficult to reproduce the recorded video information at the same time while recording the program, and the program started by the user using the timer must wait until the end of the program until the end of the program. There was a problem that it could not be seen from the head.

  In addition, there is a method in which an optical disk that is superior to a tape with random accessibility is recorded by the CLV method that is optimum in recording density as in the technique described in Patent Document 1, and the CAV method that has superior access performance during reproduction. However, in a system in which recording and reproduction are alternately repeated, no consideration is given to how the relationship between the respective target rotational speeds should be set.

  Furthermore, in the technique described in Patent Document 2, a technique for realizing time shift using a disk-shaped recording medium is described. However, a rotation control method is described on the premise that it is performed using two pickups. There was no.

In the recording / reproducing method of the present invention, during the recording operation, the rotational speed of the disk-shaped recording medium is controlled according to the recording control method of the disk-shaped recording medium. Then, during the reproducing operation, the rotational speed at the time of the previous recording operation is changed to the rotational speed at the time of the next recording operation, and in accordance with the change in the transmission rate that changes in proportion to the reproducing position in the disc radial direction, The signal read from the recording medium is demodulated, and the data is reproduced by extending the time axis.

  In the recording / reproducing method of the present invention, any of DVD-RW, DVD-RAM, and CD-RW can be used as the disk-shaped recording medium.

The recording / reproducing apparatus of the present invention includes an input means for continuously inputting data, a switching signal generating means for generating a switching signal for switching between a data recording operation and a reproducing operation, and a rotational speed of the disc-shaped recording medium. It has a rotation control means for controlling and an optical pickup. The rotation control means controls the rotational speed of the disk-shaped recording medium according to the disk-shaped recording medium recording control method during the recording operation. Further, during the reproducing operation, the rotational speed of the disc-shaped recording medium is controlled so that the rotational speed at the previous recording operation is maintained or the rotational speed at the next recording operation is changed.

In addition, the recording / reproducing apparatus changes the rotation speed during the previous recording operation from the rotation speed during the previous recording operation to the rotation speed during the next recording operation, so that the transmission rate changes in proportion to the reproduction position in the disk radial direction. In addition, it is preferable to demodulate a signal read from the disk-shaped recording medium and reproduce the data by extending the time axis.

According to the present invention, it is possible to simultaneously record an input signal and output a signal reproduced from the same medium.

  A first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a time chart showing the operation of a recording / reproducing method according to the present invention, and FIG. 2 is a flowchart of the recording / reproducing method.

  A method for simultaneously reproducing a recorded program while recording a program such as a TV program on a disc-shaped recording medium such as a DVD-RW, DVD-RAM, or CD-RW will be described below with reference to FIGS.

  The recording signal input a in FIG. 1 is a digitized video signal and audio signal input to the apparatus, and is a program such as a TV program. (However, the input may be only one of the video signal and the audio signal.) The reproduction signal output b is the above-mentioned digitized video signal and audio signal which have already been recorded, and is the signal of the recording signal input a. By simultaneously recording on the medium and reproducing the video and audio from the reproduction signal output b from the medium, a time shift of a TV program or the like is realized.

  The recording signal input a input to the recording / reproducing apparatus is divided into periods A, B, C,..., X, Y, Z, AA, AB, and a constant time interval t (t: real number). In the figure, a range in which input signals of periods X, Y, Z, and AA are processed is shown. A reproduction signal output b indicates video and audio signals output from the apparatus at the same time. The recording / reproducing c indicates a recording operation on the medium and a reproducing operation from the medium in each period. The recording signal input in period X is time axis compression from t to tr (tr; real number) by using buffer means such as RAM, and writing to the medium is performed in the range of period X recording. The signal is read from the medium in the remaining period A reproduction range (tp; t-tr) of time t. The signal read in the period A reproduction range is subjected to time axis expansion using buffer means such as a RAM to obtain a video signal and a reproduction signal during time t. Thus, by dividing the predetermined time t into the recording period and the reproduction period and switching the processing to the medium, the recording of the program program and the reproduction of another part of the program can be performed simultaneously.

The recording / reproducing control on the disc at this time will be described. The rotational speed d indicates the rotational speed of the disk, e indicates the position of the pickup that writes and reads signals on the disk, and f indicates the transmission rate of signals that are read from and written to the medium. In this embodiment, a disk defined to write a signal with a constant transmission rate at a constant linear velocity (CLV control) to a disk having a spiral track from the inner periphery to the outer periphery is targeted. For this reason, the CLV control is performed during the periods 100d1, d3, d5 during which the rotational speed is recorded on the disc. Accordingly, during the period of 100d1, d3.d5, as the pick position advances to the outer periphery with the passage of time, the rotational speed decreases in inverse proportion to the radius. In the reproduction period 100d2, the last rotation speed of the recording period 100d1 is kept. Therefore, since it coincides with the target rotation speed when the recording period 100d3 is started again, the rotation control in the recording period 100d3 is quickly stabilized. Similarly, in the reproduction periods 100d4 and d6, since the rotation speed maintains the rotation speed of the previous recording operation, the rotation speed in the recording period is quickly stabilized. In addition, the pick position gradually moves to the outer periphery within the range of the recording period 100e1, then moves to the inner periphery in order to access already recorded data, plays back during the period of 100e2, and then returns to the outer periphery again. Go to and record the continuation of 100e1 in the period of 100e3. Since the movement of the pick and the control of the rotation speed are performed, signals written on the medium at a constant transmission rate as shown in 100f1, f3, and f5 are used for CAV reproduction of a CLV recorded disc. Therefore, the transmission rate changes in proportion to the radial position of the pickup during reproduction. The signal reproduced from the disc is subjected to signal processing such as demodulation and error correction in accordance with the change in transmission rate, recorded in a buffer means such as RAM, and read out by extending the time axis at a constant rate. Output b is obtained.

  The recording method described with reference to FIG. 1 will be further described with reference to the flowchart of FIG.

  First, the disk is accessed according to the start position designated by the user (201), and if there is no instruction to end the process from the user (213), CLV rotation control 202 is performed and data is written to the disk (203). ), If the writing of the medium with respect to the input corresponding to the time t in FIG. 1 is not completed (204), (202) and (203) are repeated. If the writing of the medium has been completed (204), it is determined whether or not the user has requested reading at the same time as recording (205). If the simultaneous reading request has not been issued, (202) (203) The process (204) is repeated. On the other hand, if a request for simultaneous reading has been issued, the position at which writing is to be ended is first stored in a temporary storage device (206), the rotation speed is maintained at the position at which writing is to be ended, and writing is stopped (207). Next, if there is no instruction to end the process from the user (214), the target data on the disc is determined according to the request from the user as to where the video and audio are to be reproduced from the recorded part of the program. The recorded position is determined and the target position is accessed (208). Data is read from the target location on the medium (209). If writing of the medium to the input corresponding to time t in FIG. 1 is not completed (210), the processing of (209) is repeated. That is, reading of data from the medium is continued while maintaining the rotation speed at the time when writing is stopped. Therefore, the transmission rate of the reproduction signal during this period changes in proportion to the radius r of the pickup position as shown in FIGS. 1-100f2, f4, and f6. When the specified amount of data has been read from the medium (210), the user-specified position for reading is updated to the position where reading was stopped (211). By this operation, the next data can be read out next time. Thereafter, until the total time of the recording process and the reproducing process for the medium stored in the process 206 reaches t (215), the access is repeated to the position where the recording on the medium is stopped (212). , 203 and the subsequent recording process. Thus, recording and reproduction are performed on the medium within time t. When the user requests the end of both recording or reproduction and recording / reproduction, a determination is made at 213 during recording. If both recording / reproduction ends, the process ends (213a), and if only recording ends, 207. More reproduction processing is performed (213b). Similarly, during playback, a determination is made at 214, and if both recording and playback are completed, the processing is terminated (214a), and if playback is completed, recording processing from 212 is performed (214b).

  In this way, in the present embodiment, the recording is performed every time t, and the recording of the signal input at time t and the reproduction of the signal output at time t are switched every time t. In addition, the CLV control is performed at a constant transmission rate during recording, and the rotational speed when switching from recording to playback is maintained during playback. Therefore, the target rotational speed of the CLV is maintained even when switching from playback to recording. Since it is held, it can be pulled in immediately, realizing stable rotation control and highly reliable writing. Further, since the linear velocity is constant and the transmission rate is constant, it is particularly suitable for realization with a phase change disk. Accordingly, while recording a currently input signal such as a TV program on the medium, it is possible to simultaneously reproduce the recorded part, thereby realizing a time shift function for the TV program.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  FIG. 3 is a time chart showing the operation of the recording / reproducing method according to the present invention. FIG. 1 shows a method of simultaneously reproducing a recorded program while recording a program such as a TV program, but shows an operation including only recording in the apparatus realizing the operation of FIG. Yes. FIG. 1 shows a state in which only the recording is performed during the reproduction of the period A. During this time, the rotational speed is maintained at the same rotational speed as that of 100d2 (200d2). In order to maintain the current position of the pick, a track jump is performed and the pause operation is continued (200e2). Since the reproduction operation is stopped, 200f1 corresponding to 100f1 is not shown. By controlling in this way, it is possible to easily perform only recording with an apparatus that presupposes recording and reproduction simultaneously. Similarly, it is also possible to easily perform reproduction only with an apparatus that presupposes recording and reproduction simultaneously.

In FIG. 2, the recording only operation is realized by a path of 214 → 212 → 215 → 213 → 202 → 203 → 204 → 205 → 216 → 213. The reproduction only operation is realized by a path of 213 → 207 → 208 → 214 → 209 → 210 → 211 → 212 → 215 → 213.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  FIG. 4 is a block diagram of a recording / reproducing apparatus according to the present invention. In FIG. 4, reference numeral 413 denotes a tuner for receiving TV broadcasts, and reference numeral 414 denotes an encoder that digitizes an input video signal or audio signal and performs compression processing typified by MPEG. The signal is written into the buffer RAM 409 via the buffer RAM write control means 415. The data written in the buffer RAM is sent to the correction code adding circuit 417 via the buffer RAM write control means 416 and added with an error correction code. Then, the data is modulated in the modulation circuit 418. And is written to the disk 401. At this time, the disc 401 is rotated by the disc motor 405. 403 is an optical pickup that detects an optical signal from a disk and converts it into an electrical signal, 404 is a preamplifier, 420 is a wobble detection means for detecting a wobble component from a recording track wobbled in a recording medium such as a CD-R or DVD-RAM. And the detected wobble component becomes the detection information of the linear velocity. Reference numeral 421 denotes a reference generation circuit that gives a target linear velocity. The comparison circuit 422 calculates which of the reference from 421 and the detection signal from 420 is faster. The rotation control circuit 423 is controlled so that the disk motor 401 is accelerated if the detection signal is slower, and the disk motor 401 is decelerated if the reference signal is slower, so that the linear velocity is equal to the reference. On the other hand, the reproduction signal from the disc 401 is demodulated by the demodulating circuit 405, further subjected to error correction processing by the correction processing circuit 406 in accordance with the error correcting code added by 417, and then buffered via the buffer RAM write control means 407. It is written in the RAM 409. The signal written in the buffer RAM is input to the video / audio decoder 411 via the buffer RAM reading means 410. The video / audio decoder 411 performs decompression processing according to the compression rule of the video / audio encoder 414 and converts it into an analog signal that is sent to the monitor and speaker 412. Reference numeral 427 denotes mode switching means for sending recording / reproduction simultaneous, recording, reproduction, and stop modes to the recording / reproduction switching signal generation circuit 425. The timing generation circuit 426 generates a signal having a period of time t. In the recording / reproduction switching signal generation circuit 425, in the recording / reproduction simultaneous mode, a switching signal is generated by dividing the t period into a recording period tr and a reproduction period tp. The input signal from 415 input at time t can be recorded at time tr, and the data output from 410 per time t can be sufficiently reproduced during time tp to reproduce video and audio signals. After selecting the read rate of the buffer RAM read control means 416 in accordance with the transmission rate, the recording system processing means consisting of 416, 417, and 418 is enabled during the tr period, and the rotation control system 424 consisting of 422 and 423 is activated. The laser 402 is set to the recording mode, the last rotation speed of the tr period is maintained during the period tp, the reproducing system means 408 comprising 405, 406, and 407 is activated and the laser 402 is switched to the reproducing mode. Since the signal reproduced from the disc 402 is CAV-controlled as the signal recorded by CLV control, the transmission rate of the input signal changes, but the reproduction system means 408 performs processing according to the input transmission rate. Do. Thus, while recording a currently input signal such as a TV program on the medium, the recorded part can be reproduced simultaneously, and a time shift function for the TV program is realized. In this embodiment, the video signal and the audio signal input from the tuner are digitized and compressed. However, these processes may be performed on the tuner side, and the broadcast wave itself is digitally compressed. In some cases, the signal is given to

  Next, a fourth embodiment of the present invention will be described with reference to FIG.

  FIG. 5 is a block diagram of a recording / reproducing apparatus according to the present invention. FIG. 5 has the same configuration as FIG. 4 except for the read byte counter 501, the read end signal 502, and the recording / reproducing switching signal generation circuit 503. The read byte counter 501 counts the number of bytes read by the buffer RAM read control unit 416 starting from the start timing of the t period, and reaches the number of bytes written to the buffer RAM via the buffer RAM write control unit 415 per t time. A read end pulse 502 is issued every time. The recording / reproduction switching signal generation circuit 503 generates a switching signal in which the period from the beginning of the t period to the generation of the read end pulse 502 from the timing generation circuit 426 is a recording period tr and the rest is divided into a reproduction period tp. Therefore, even when recording needs to be written in another location due to a defect on the disk, recording can be performed without interruption even if recording is not completed at the previously calculated tr. When the tp period is insufficient, the lack of reproduction data can be compensated by holding the video of the previous frame. Also, the generation of abnormal noise can be prevented by muting the audio signal. In addition, the audio signal has priority over the medium over the medium, and part of the video signal with a larger capacity than the audio signal is lost, and the video signal retains the video of the previous frame so that the audio signal is not interrupted. Therefore, even if the tp period is insufficient, playback can be performed without making the viewer feel unnatural.

  As described above, according to this embodiment, even if a medium has a defect, recording is not interrupted, and an arbitrary portion of recorded data can be read during recording.

Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a time chart showing the operation of the recording / reproducing method according to the present invention, FIG. 7 is a diagram showing a disk that performs recording / reproducing by the recording / reproducing method according to the present invention, and FIG. 8 is a flowchart of the recording / reproducing method. It is. In this embodiment, a spiral track is formed from the inner periphery to the outer periphery, and the disk on which recording / reproduction is normally performed from the inner periphery to the outer periphery is divided into a plurality of zones as shown in FIG. 7a. As shown in FIG. 7b, one zone is composed of a plurality of tracks. In FIG. 7 a, the whole is divided into 10 zones from zone 1 to zone 10. The operation of FIG. 6 will be described assuming the disk of FIG.

  The recording signal input a input to the recording / reproducing apparatus, the video and audio signal reproduction signal output b output from the apparatus at the same time, the recording operation to the medium in each period, and the reproducing operation c from the medium are the same as in FIG. . The time axis compression process for the recording signal input and the time axis extension process for the signal read from the medium are performed in the same manner as in FIG. Thus, by dividing the predetermined time t into the recording period and the reproduction period and switching the processing to the medium, the recording of the program program and the reproduction of another part of the program can be performed simultaneously.

  The recording / reproducing control on the disc at this time will be described. The rotational speed d indicates the rotational speed of the disk, e indicates the position of the pickup that writes and reads signals on the disk, and f indicates the transmission rate of signals that are read from and written to the medium. As in FIG. 1, the CLV control is performed in the periods 600d1, d3, and d5, and the last rotation speed of the recording period 600d1 is continuously held in the reproduction period 600d2. The pick position control is different from the operation shown in FIG. Recording starts from the outermost zone 10 and continues in the inner zone. FIG. 6 shows that recording is performed in zones 3 and 2. Accordingly, the position of the pick gradually moves to the outer peripheral side within the range of the recording periods 600e1 and 600e3 in the zone 3, but moves to the inner zone 2 when the recording on the zone 3 is completed. Therefore, if the already recorded data is to be accessed for reproduction, the same zone or an outer zone is always accessed. In FIG. 6, after the recording in the recording period 600e1 of the zone 3 is completed, the 600e2 in the outer zone 10 is accessed. Therefore, as shown in 600f1, f3, and f5, signals written to the medium at a constant transmission rate will be CAV-reproduced on the outer peripheral side while maintaining the rotational speed of the CLV-controlled disc during recording. The transmission rate of the signal reproduced from the disc changes depending on the position, but is always higher than the transmission rate at the time of recording. Since the reproduction system is relatively easy to process at a high transmission rate compared to recording, it is easy to control the recording time tr and the reproduction time tp within the range of t. In addition, since access from the outer periphery to the inner periphery is performed only when moving between zones, and recording and reproduction are performed sequentially from the inner periphery to the outer periphery along a spiral track in the zone, from the inner periphery such as a CD-RW. It can be easily configured using a device that performs recording and reproduction toward the outer periphery, and the apparatus according to the present embodiment enables recording and reproduction of an existing disk that performs recording and reproduction from the inner periphery toward the outer periphery. Becomes easy. Further, when the recording / reproducing apparatus of the present invention is configured using an existing disk such as a CD-RW, the disk recorded by the recording / reproducing apparatus according to the present invention is accessed at a discontinuous point for each zone even in the existing CD-RW drive. Playback is possible because it is only performed.

  The recording method described with reference to FIGS. 6 and 7 will be further described with reference to the flowchart of FIG.

The flowchart in FIG. 8 is basically the same as that in FIG. 2 except that processes 801, 802, 803, and 804 are added. Reference numeral 801 denotes a zone number in which the pick is currently recording at the time of recording. n is a process for determining whether the end point of n has been reached. If the end point of n has not been reached, the processes of 213, 202, 203, 204, and 205 are repeated. Zone No. When the end point of n is reached, the zone No. 1 which is the inner zone is reached. Access to n-1. On the other hand, reference numeral 803 denotes a zone No. in which the pick is currently being reproduced during reproduction. m is a process for determining whether the end point of m has been reached. If the end point of m has not been reached, the reproduction processes 209 and 210 are repeated.

  Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 9 shows a disk in which a spiral track is formed from the inner periphery to the outer periphery, and recording / reproduction is usually performed from the inner periphery to the outer periphery. As shown in FIG. Zone CLV is divided into a plurality of zones from 1 to the outermost zone 10, and the zone is subjected to CAV control for recording at a constant rotational speed, and the rotational speed of each zone is made inversely proportional to the radial direction and the rotational speed is reduced toward the outer periphery. The time chart at the time of applying this invention with respect to the disc which records is shown. A, d, c, and e in this time chart are the same as those in FIG. Therefore, also in this embodiment, recording / reproduction is performed from the inner circumference to the outer circumference in each zone, and recording / reproduction is performed from the outer circumference to the inner circumference in each zone. Also, the rotation speed is the zone CLV method during recording, and during playback, the rotation speed immediately before switching from recording to playback is maintained, so that the recording speed is constant during the recording process. Become. Regarding the transmission rate f, the transmission rate at the time of recording is subjected to zone CLV control, and 900f1, 3, 5, 7, and 9 all have the same transmission rate. Also, the transmission rate at the time of reproduction is higher because 900f2 holds the rotational speed at a rotational speed suitable for 900f1 on the inner periphery. Further, since it is recorded by the zone CLV control, the transmission rate is constant during each period of 900f2, 4, 6, 8, and 10. However, although not shown in FIG. 9, when the zone changes within each recording period of 900 e 1, 3, 5, 7, 9, the rotational speed changes to the rotational speed corresponding to the zone at the time of change, and 900 e 2 , 4, 6, 8, and 10, when the zone changes during playback, the playback transmission rate changes in a stepwise manner at the time when the zone changes. This operation is shown in FIG. FIG. 11 is a time chart, which is common to the time chart of FIG. 6 except for 1100d3, e3, f3 and 1100d4, e4, f4. If the zone 3 changes to zone 2 in the middle of the recording period as indicated by 1100e3, the rotational speed changes so as to be suitable for zone 2 as indicated by 1100d3. At this time, the recording transmission rate is written at a constant transmission rate as indicated by 1100f3. When the zone 10 is changed to the zone 9 in the middle of the playback period as shown in 1100e4, the rotation speed is maintained as shown in 1100d4, so the transmission rate of the playback signal is in the middle of the period as shown in 1100f4. Change. Thus, even if the zone changes during the recording period or the reproduction period, the reproduction period continues to be held at the rotation speed target value at the end of the recording period, that is, the rotation speed target value at the beginning of the recording period. Can be quickly stabilized. As described above, the present embodiment has shown that the present invention can be applied to a medium employing the zone CLV method. In a medium employing the CLV method at the time of recording as in the fifth embodiment, when the recording location and the playback location are in the same zone, the transmission rate of the reproduced signal is substantially the same as the transmission rate at the time of recording. However, in the zone CLV system of this embodiment, the same transmission rate is obtained even in the same zone, and the transmission rate during reproduction can always be higher than the transmission rate during recording. In this embodiment, since the rotation speed in the zone can be made constant, the rotation speed can be controlled more easily. Since the transmission rate at the time of reproduction does not always change, the processing of the reproduction system becomes easy.

  Next, a seventh embodiment of the present invention will be described with reference to FIG. FIG. 10a is a block diagram showing an example of a logical format in the case of recording a video / audio signal encoded on a disc according to a compression standard such as MPEG. FIG. 10b is a diagram showing the relationship between the logical format and the zones in the fifth and sixth embodiments. The interleave block in FIG. 7a skips and plays back in order to realize processing such as 1) selecting one story from a plurality of branched stories and 2) skipping a part of the story without interruption. It is a unit. That is, a unit for performing discontinuous reproduction. In FIG. 10a, the interleave blocks 2, 4, and 5 are skipped, and the interleave blocks 1, 3, and 6 are reproduced in this order. FIG. 10b shows the relationship between interleave blocks and zones. Each interleave block is recorded in one zone without being divided. Therefore, the occurrence of a discontinuity in the playback order at a zone break always coincides with the location where the discontinuity is defined in the logical format.

  As described above, according to the present embodiment, the portion where the playback order is discontinuous due to the break of the zone is a discontinuous portion of the logical format in the video playback device. It can also be played back by the device.

  Next, an eighth embodiment of the present invention will be described with reference to FIG. FIG. 12 shows a time chart of the recording / reproducing method according to the present invention. This embodiment relates to a case where recording is performed not on continuous portions of the medium but on skipped portions. Except for the parts described below, the same operations as in FIG. 1 are performed. A description will be given below. When recording, erasing and overwriting are repeated, the recordable location on the medium may not be a continuous area. In this case, as shown in FIG. 8, the end point of the recording period 1100e1 and the start point of the subsequent recording period 100e3 may not be the same.

In this case, in the reproduction period 1100e2 between the recording period 1100e1 and the recording period 100e3, the rotational speed control is controlled so as to be equal to the rotational speed target of the starting point of 100d3 instead of holding the end point of 100d1 as indicated by 1100d2. Yes. As long as the control rotates stably at the target value at the end point of the period of 1100d2, the speed may be gradually adjusted over the entire period, or the speed may be adjusted using a part of the period. As described above, according to the present embodiment, even when recording is performed on a skipped place, since the rotation is stable at the start point of the recording period, the recording can be performed stably. Also, during the playback period, there is no problem in playback even if the playback transmission rate changes greatly by using a wide capture PLL.

  According to these embodiments, while a currently input signal such as a TV program is recorded on the medium, the recorded part can be reproduced simultaneously, and a time shift function for the TV program is realized.

  In the above embodiments, the data to be recorded and the data to be reproduced are described as video data or audio data. However, the present invention is not limited to this, and digital data distribution such as character information is recorded. Also good. These data may be combined and recorded / reproduced.

  In the above embodiment, the disk rotation control during the playback period is basically constant angular velocity control. However, if normal recording within the recording period and normal playback within the playback period are possible. The disc rotation control during the reproduction period may be constant linear velocity control.

1 is a timing chart showing a digital signal recording / reproducing method according to an embodiment of the present invention. 1 is a flowchart showing a digital signal recording / reproducing method according to an embodiment of the present invention. 1 is a timing chart showing a digital signal recording / reproducing method according to an embodiment of the present invention. 1 is a block diagram of a digital signal recording / reproducing apparatus according to an embodiment of the present invention. 1 is a block diagram of a digital signal recording / reproducing apparatus according to an embodiment of the present invention. 1 is a timing chart showing a digital signal recording / reproducing apparatus according to an embodiment of the present invention. 1 is a disk shape diagram used in a digital signal recording / reproducing apparatus according to an embodiment of the present invention. 1 is a flowchart showing a digital signal recording / reproducing method according to an embodiment of the present invention. 1 is a timing chart showing a digital signal recording / reproducing method according to an embodiment of the present invention. The block diagram which shows the digital signal recording / reproducing method which is one Example of this invention. 1 is a timing chart showing a digital signal recording / reproducing apparatus according to an embodiment of the present invention. 1 is a timing chart showing a digital signal recording / reproducing apparatus according to an embodiment of the present invention.

Explanation of symbols

401 ... Storage medium 403 ... Pickup 404 ... Preamplifier 405 ... Demodulation means 406 ... Error correction means 407 ... Buffer RAM read control means 409 ... Buffer RAM 416 ... Buffer RAM write control means 417 ... Add correction code Circuit, 418 point modulation circuit, 420 ... wobble detection means, 422 ... comparison circuit, 423 ... rotation control circuit, 425 ... recording / reproduction switching signal generation circuit, 426 ... timing generation circuit.

Claims (4)

A recording / reproducing method for alternately performing a data recording operation and a reproducing operation on a disk-shaped recording medium,
The recording operation is performed by a recording method in which the spindle rotation speed changes at the radial position of the disk,
When the end point of the nth (n is a natural number) recording operation and the start point of the (n + 1) th recording operation are not continuous on the disc-shaped recording medium, the interval between the nth recording operation and the (n + 1) th recording operation During the reproducing operation, the disk-shaped recording medium rotation speed at the starting point in the (n + 1) th recording operation is changed,
Recording that reproduces the data by demodulating the signal read from the disk-shaped recording medium in accordance with the change in the transmission rate of the reproduction signal during the reproduction operation accompanying the change in the rotation speed, and extending the time axis Playback method.   The recording / reproducing method according to claim 1, wherein the disc-shaped recording medium is one of a DVD-RW, a DVD-RAM, and a CD-RW. A recording / reproducing apparatus for alternately recording and reproducing data on a disc-shaped recording medium,
Input means for continuously inputting the data;
A switching signal generating means for generating a switching signal for intermittently switching between the data recording operation and the reproducing operation;
Rotation control means for controlling the rotation speed of the disc-shaped recording medium;
An optical pickup that irradiates the disk-shaped recording medium with laser light, records the data on the disk-shaped recording medium, and reproduces the data recorded on the disk-shaped recording medium;
During the recording operation, the rotation control means controls the rotational speed of the disk-shaped recording medium according to a recording method in which the spindle rotational speed changes at the radial position of the disk. When the end point of the n-th recording operation and the start point of the (n + 1) -th recording operation are not consecutive during the reproducing operation between the (natural number) recording operation and the (n + 1) -th recording operation ( n +1) A recording / reproducing apparatus that controls the rotational speed of the disk-shaped recording medium so as to be changed to the disk-shaped recording medium rotational speed at the start point of the first recording operation. A signal read from the disk-shaped recording medium is demodulated in accordance with a change in a transmission rate of a reproduction signal during the reproduction operation according to the change in the rotation speed, and the data is reproduced by extending the time axis. Item 4. The recording / reproducing apparatus according to Item 3.

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