JPH10320923A - Disk apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video disk apparatus which can continuously reproduce digital animation images stored in different radial areas on an optical disk without interruptions by one optical head. SOLUTION: Digital animation image data reproduced from an optical disk 17 by an optical head 16 are inputted to an MPEG decoder 18 via a buffer memory 14 and reproduced by a monitor 19. At this time, the digital animation images recorded in different radial areas on the optical disk 17 are reproduced in a preliminarily set order. For this purpose, the digital animation video image data of not smaller than an access time of the optical head 16 are reproduced from the optical disk 17 at a higher speed than a bit rate and stored in the buffer memory 14. When the optical head 16 is present within the area and is accessing between a plurality of areas, the digital animation video data are continuously read and reproduced from the buffer memory 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive for recording and reproducing digital continuous data such as digital moving image data, and more particularly, to a digital continuous data recorded in different radial positions on a recording medium. The present invention relates to a disk device having a function of continuously reproducing.

[0002]

2. Description of the Related Art MPEG (Moving Picture Expert Group)
p) using digital video compression technology represented by
2. Description of the Related Art A video disk device for recording and reproducing digital moving images on a storage medium such as an optical disk has been developed.

According to a video disk apparatus using a conventional optical disk, a digital moving image compressor MPEG
Digital moving image data compressed by an encoder or digital moving image data distributed by broadcasting or CATV (cable television) is temporarily stored in a buffer memory, and the bit rate of the input digital moving image data is stored in the buffer memory. The difference between (the bit capacity sent per second) and the recording / reproducing speed of the optical disc (bit capacity that can be recorded / reproduced per second) is adjusted. Usually, the bit rate of the input digital moving image data is lower than the recording / reproducing speed of the optical disk.

One use of such a video disk device is to reproduce a plurality of digital moving images recorded in an optical disk area at different positions in a radial direction of the optical disk in an arbitrary order. For example,
Now, assume that the digital moving image D1 starting from the position of the radius R1, the digital moving image D3 at the position of the radius R3, and the digital moving image D2 at the position of the radius R2 are reproduced in this order. However, R1 <R2, R3. In this case, after reproducing the digital moving image starting from the radius R1, the optical head is moved (seeked) to the position of the radius R3 to reproduce the digital moving image D3. Thereafter, the optical head is moved to the radius R2.
And the digital moving image D2 is reproduced.

Here, when the optical disk is accessed by the optical head, image data cannot be reproduced from the optical disk. Therefore, when the reproduction of the image D1 is changed to the reproduction of the image D3, or when the reproduction of the image D3 is changed to the reproduction of the image D2. The image is interrupted when switching to. Therefore, moving images cannot be reproduced continuously. In order to solve this problem, two optical heads are used in a laser disk device or the like, and one is set at a radial position where the current reproduction is performed, and the other is set at a radial position where the next reproduction is performed. A technique has been proposed in which a moving image is continuously reproduced by switching heads at times to eliminate a non-reproduction period due to access. However, this method has a major disadvantage in that the cost is increased because two optical heads are used.

[0006]

As described above, in a conventional disk device having a single optical head, a plurality of digital moving images recorded in regions at different positions in the radial direction on the disk can be arbitrarily set. When playing back in order, there is a problem that the image is interrupted during the access of the optical head and it cannot be played back continuously.In addition, digital moving images recorded in areas at different positions in the radial direction without interruption using multiple heads An apparatus capable of reproducing an image has a problem that the cost is high.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a plurality of digital continuous data stored in regions at different positions in a radial direction on a recording medium are continuously reproduced by one recording and reproducing head without interruption. It is an object of the present invention to provide a disk device capable of performing the following.

The present invention relates to a disk device for recording and reproducing digital continuous data by a recording / reproducing head using a disk-shaped recording medium, and a buffer memory for temporarily storing digital continuous data reproduced from the recording medium. And control means for performing control for sequentially reproducing digital continuous data recorded in a plurality of areas at different positions in the radial direction on the recording medium in a predetermined order. Here, the control means includes:
(A) reproducing, from the recording medium, digital continuous data for a time longer than an access time between the plurality of areas of the recording / reproducing head at a speed higher than a bit rate of the digital continuous data, and storing the data in the buffer memory; (B)
When the recording / reproducing head is in the area and while moving between the plurality of areas, continuous data stored in the buffer memory is continuously read and reproduced.

According to the disk apparatus of the present invention thus configured, a plurality of digital continuous data, for example, moving image data, stored in regions at different positions in the radial direction on the recording medium, can be recorded by one recording / reproducing head. Images can be reproduced continuously without interruption.

In the disk apparatus of the present invention, the digital moving image data recorded on the recording medium is reproduced at a speed higher than the bit rate of the digital moving image data and stored in the buffer memory. The moving image data is read out at the bit rate and the moving image is reproduced.

Here, the reproduction speed from the recording medium (readout)
speed) is higher than the bit rate of the digital video data, so there is a speed difference between the speed at which the digital video data is stored in the buffer memory and the speed at which the digital video data is read from the buffer memory. Accumulates,
When the capacity of the buffer memory becomes full, the reproduction from the recording medium is temporarily suspended. During this time, the digital moving image data is read from the buffer memory at the bit rate, and the moving image is reproduced.

When the digital moving image data recorded in the buffer memory is reduced to an appropriate capacity, reproduction from the recording medium is performed again. Therefore, the reproduction of the digital moving image data from the recording medium is performed intermittently, and the reading of the digital moving image data from the buffer memory is performed continuously.

If the time during which reproduction from the recording medium is paused is set to be longer than the average access time of the recording / reproducing head,
Using this time, the recording / reproducing head can be moved to an area at a different arbitrary position on the recording medium in the radial direction, and other digital moving image data recorded in that area can be reproduced. During the access, the digital moving image data recorded in the area at the radial position of the recording medium before the recording / reproducing head moves is read from the buffer memory. Subsequently, the digital moving image data is reproduced from the recording medium at the position where the recording / reproducing head has moved, stored in the buffer memory, and read from the buffer memory at the bit rate of the digital moving image data.

Therefore, even while the recording / reproducing head is moving, the digital moving image data is read out from the buffer memory and reproduced, so that the digital moving image data recorded in the radially different areas on the recording medium is recorded. Can be reproduced without interruption.

Next, the storage capacity required for the buffer memory in the present invention will be described. Basically, the storage capacity required for the buffer memory is such that the bit rate of digital moving image data is A (bps) and the maximum access time to the recording medium (the time when the recording / reproducing head moves from the innermost circumference to the outermost circumference of the recording medium). Is the time obtained by adding the time required for the recording medium to make one rotation to the seek time required for
More than A * S bits. By providing a buffer memory having such a capacity, the difference between the reproduction speed of digital moving image data from the recording medium and the bit rate of the digital moving image data is used to obtain the digital moving image for the access time of the recording / reproducing head. Data can be stored in the buffer memory in advance.

When the seek is retried when the seek fails, the bit rate of the digital moving image data is set to A
(Bps) and N is the number of seek retries,
The storage capacity of the buffer memory may be A * S * (N11) bits or more.

In a video disk apparatus having a function of automatically changing a recording medium, the maximum time required for changing the recording medium and the maximum access time to the recording medium (when the recording / reproducing head moves from the innermost circumference of the recording medium to the When the sum of the seek time required to move to the outer circumference and the time required for the recording medium to make one rotation) is S seconds, and the bit rate of the digital moving image data is A (bps), The storage capacity may be A * S bits or more. With this configuration, digital moving image data for the medium exchange time and the medium access time can be stored in the buffer memory in advance, and can be read out from the buffer memory during these times. , A plurality of digital moving image data over an area at an arbitrary position different in the radial direction can be reproduced without interruption.

Further, when the seek and the medium exchange are retried when the seek fails and the recording medium exchange fails,
The maximum time required for exchanging the recording medium is S1 second, the number of retries when the exchange of the recording medium fails is N1, the maximum access time to the recording medium (for moving the recording / reproducing head from the innermost circumference to the outermost circumference of the recording medium). The recording medium is 1 for the required seek time.
Assuming that S2 seconds is the time obtained by adding the rotation time, N2 is the number of retries in case of seek failure, and A (bps) is the bit rate of the digital video data, the storage capacity of the buffer memory is A * S1 * (N1 + 1). ) + A * S2 * (N21) bits or more.

Further, in the present invention, digital moving image data recorded in an arbitrary region among a plurality of regions at different positions in the radial direction on the recording medium is edited and converted into one digital moving image on the recording medium. When recording,
If digital video data, which is expected to be a reproduced image after editing, is controlled to be continuously reproduced before editing, the editing can be confirmed in advance, thereby improving the editing efficiency.

[0020]

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

A disk drive according to an embodiment of the present invention shown in FIG. 1 includes an analog image input unit 11, an MPEG encoder 12 as a digital moving image data compressor, a digital image input unit 13, a buffer memory 14, a modem 1
5, a video disk device including an optical head 16, an optical disk 17, an MPEG decoder 18 as a digital moving image data decompressor, a monitor 19 for displaying an image, a controller 20 for controlling each unit, and a driver 21 for driving the optical head 16 It is. The buffer 14 is composed of a memory that can be read and written at the same time, for example, a dual port memory.

Next, the operation of the video disk device according to this embodiment will be described.

In the following description, it is assumed that the bit rate of the digital moving image data output from the MPEG encoder 12 and the digital image input unit 13 is 4 Mbps. Also, as shown in FIG. 2, the optical disc 17 has a recording area 31 in which digital moving picture A data is recorded, a recording area 32 in which digital moving picture C data is recorded, and a recording area 33 in which digital moving picture B data is recorded. I do. Also,
The digital moving image data is 8 Mb on the optical disk 17 by a constant linear velocity (Constant Linear Velocity) method.
ps, and the optical disk 17 at the same speed.
It shall be reproduced from above. Also, the maximum access time to the optical disk 17 (the optical head 16
The time required for the optical disk 17 to make one rotation is added to the seek time required to move from the innermost circumference to the outermost circumference of No. 7). Further, the storage capacity of the buffer memory 14 is 4M bits.

In the following operation, the recording and reproduction of the optical disk 17 by the optical head 16, the writing / reading operation of the buffer memory 14, and the like are all controlled by the controller 20.

(Digital Video Recording Operation) First, the digital video recording operation will be described with reference to the flowchart of FIG.

It is determined whether the input moving image signal is an analog moving image signal such as an NTSC signal (ST).
1) When it is an analog moving image signal, the analog moving image signal is output from the analog image input unit 11 to the MPEG encoder 1
2 (ST2), and the MPEG encoder 12
Is subjected to image compression (ST3), and then input to the digital image input unit 13 (ST4).

On the other hand, CATV and satellite broadcasting (satellite bro
The already compressed digital moving image data delivered from an adcast or the like is directly input from the digital image input unit 13 to the buffer memory 14 (ST4). At this time, the digital moving image data input from the digital image input unit 13 is written into the buffer memory 14 at a speed of, for example, 4 Mbps and stored there (ST5).

Next, it is determined whether or not the amount of data stored in the buffer memory 14 is equal to or less than a predetermined amount (ST6). If this determination is NO, image data is read from the buffer memory 14 (ST7) and the optical disk 17 is read. (ST8). If the determination is YES, the recording of image data on the optical disk is interrupted for a predetermined time, and the operation proceeds to step S
The process returns to T6 (ST9).

As described above, the speed (8 Mbps) at which digital moving image data is recorded on the optical disk 17 via the optical head 16 is higher than the bit rate (4 Mbps) of the compressed digital moving image data sent from the MPEG encoder 12. Since the speed is high, the digital moving image data input from the digital image input unit 13 is once stored in the buffer memory 14. Then, after digital moving image data having a capacity suitable for recording on the optical disk 17 (such as one sector or one track of the optical disk 17) is stored in the buffer memory 14, the digital moving image data is transferred from the buffer memory 14 at a speed of 8 Mbps. Data is read (ST7). That is, the controller 2
0 writes digital moving image data from the image input unit 13 at a speed of 8 Mbps to the buffer memory 14, and when moving image data for one sector or one track is written to the buffer memory 14, the digital moving image data is written at a speed of 8 Mbps. From the buffer memory 14.

The digital moving image data read from the buffer memory 14 is guided to a modulator / demodulator 15 where it is modulated and processed into a signal suitable for recording by a semiconductor laser (not shown), an objective lens, and a photodetector. The light is input to a known optical head 16 as a main component, and is recorded on an optical disk 17 by the optical head 16 (ST8). The optical disk 17 is a recordable / reproducible medium, specifically, a phase change recording medium, a magneto-optical recording medium, or the like. Even during the recording of digital moving image data on the optical disk 17 by the optical head 16, the digital moving image data input from the digital image input unit 13 is stored in the buffer memory 14 at a speed of 4 Mbps.

(Normal Digital Video Reproduction Operation) When reproducing the data of the video A recorded in the recording area 21 of the optical disk 17, the controller 20 sets the driver 21 to the reproduction mode, and While watching the header information, the digital moving image A
Optical head 16 in the radial direction toward the start of the recording area of
To move. When the optical head 16 reaches the start point of the recording area, the optical head 16 reads digital moving image data from the optical disk 17 at a speed of 8 Mbps. The read digital moving image data is written into the buffer memory 14 via the modem 15 at a speed of 8 Mbps. Thereafter, the digital moving image data is read from the buffer memory 14 to the MPEG decoder 18 at a bit rate of 4 Mbps. The MPEG decoder 18 expands the read digital moving image data. The expanded digital moving image data is sent to the monitor 19 and displayed.

(Operation for Continuously Reproducing a Plurality of Moving Images) Next, an operation for continuously reproducing a plurality of digital moving image data recorded in recording areas having different radial positions on the optical disc 17 without interruption of the image will be described. This will be described with reference to FIGS.

FIG. 4 shows a change in the amount of digital moving image data in the buffer memory 14 when a plurality of digital moving image data are reproduced. 5A, 5B, 5C, and 5C show how the contents of the buffer memory 14 at times ta, tb, tc, td, tc, and tf on the graph of FIG. (D), (e),
(F) shows each. In (a) to (f) of FIG. 5, one rectangle represents 1M bits of digital moving image data.

Here, an example is shown in which the data of the digital moving image A is reproduced for 3 seconds and then the data of the moving image B is reproduced. As shown in the flowchart of FIG. 6, first, after moving the optical head 16 to the recording area 21 (ST21), 8
Data of the digital moving image A is reproduced from the recording area at a speed of Mbps (ST22). At this time, it is determined whether the buffer memory 14 is full (ST23), and if this determination is NO, it is stored in the buffer memory 14 (ST2).
4) and read from the buffer memory 14 at a speed of 4 Mbps and output to the MPEG decoder 18 (ST2)
5). Due to the speed difference between the reading speed from the optical disk 17 and the bit rate of the digital moving image, the time t
a in the buffer memory 14 (8 Mbps-4 Mbps)
s) * 1 second = 4 Mbits of digital moving image data is stored. This is shown in FIG.

As shown in FIG. 5A, when the storage capacity of the buffer memory 14 becomes 4 Mbits, that is,
If the determination in step ST23 is NO, the next time tb
The reproduction of the digital moving image data from the optical disk 17 is interrupted for a predetermined period of time for 0.5 seconds until step ST2.
Return to 3 (ST21). However, even during this time ta-tb, the digital moving image data stored in the buffer memory 14 is read out at a speed of 4 Mbps and output to the MPEG decoder 18 so that the moving image A displayed on the monitor 19 is reproduced. Are performed continuously. During this time, no new digital moving image data is input to the buffer memory 14, so that the digital moving image data in the buffer memory 14 is 4M bits−4Mbps * 0.5 seconds = 2M bits. This is shown in FIG.

During the next 0.5 seconds from time tb-tc, the data of the moving image A is read from the optical disk 17 at a speed of 8 Mbps and stored in the buffer memory 14. The digital moving image data stored in the buffer memory 14 during this 0.5 second is 2 Mbits + (8 Mbps−4 Mbps).
ps) * 0.5 seconds = 4 Mbits. This is shown in FIG.
(C).

The digital moving image data reproduced from the optical disk 17 between time 0 and time tc is
8 Mbps * (1 second + 0.5 second) = 12 M bits. Since this is the capacity of the digital moving image for 3 seconds, the reproduction of the data of the moving image A from the optical disk 17 is stopped. Since it takes 0.5 seconds for the data of the digital moving image A of 4 M bits stored in the buffer memory 14 to be reduced to 2 M bits, the data of the digital moving image B recorded in the recording area of the digital moving image B during this time is required. The data may be accessed by moving the optical head 16 to the start position. Since the maximum access time is 0.25 seconds, the operation of the optical disk 17 is stopped for the first 0.25 seconds.

During the next time tc-td of 0.25 seconds, the optical head 16 moves to the start position of the digital moving image B data. During this time, the data of the digital moving image A stored in the buffer memory 14 is read at a speed of 4 Mbps and output to the MPEG decoder 18, so that the reproduction of the data of the moving image A displayed on the monitor 19 is not interrupted. Done. During this time, no new digital moving image data is input to the buffer memory 14, so that the digital moving image data in the buffer memory 14 is 4M bits-4Mbps * 0.5 seconds = 2M bits. This is shown in FIG.

During the next time td-te of 0.25 seconds, the data of the moving image B is read from the optical disk 17. The digital moving image data stored in the buffer memory 14 in this 0.25 second is 2 Mbps (8 Mbps-4).
Mbps) * 0.25 seconds-3 Mbits. This is shown in FIG. 4M at the time of te
bpS * 0.25 seconds = IM bits of digital moving image A data is read from the buffer memory 14 and
Output to the EG decoder 18 and 8 Mbps * 0.25 =
Since the data of the digital moving image B of 2M bits is reproduced from the optical disk 17 and stored in the buffer memory 14, the contents of the buffer memory 14 are 1M bits of the data of the digital moving image A as shown in FIG. The data of the digital moving image B is 2M bits.

For the next time te-tf of 0.25 seconds, the data of the moving image B is read from the optical disk 17. The digital moving image data stored in the buffer memory 14 for 0.25 seconds is 3 Mbits + (8 Mbps-4).
Mbps) * 0.25 seconds = 4 Mbits. This situation is shown in FIG. The contents of the buffer memory 14 are all digital moving picture data B. Thereafter, the digital moving picture B data is read out from the buffer memory 14 and output to the MPEG decoder 18, and the digital moving picture B is displayed on the monitor 19. Will be.

During access by the optical head 16, the data of the digital moving image A stored in the buffer memory 14 in advance is read and output to the MPEG decoder 18.
When all the data of the digital moving image A in the buffer memory 14 has been read, since the data of the digital moving image B has already been stored in the buffer memory 14,
It is output to the MPEG decoder 18 continuously.

The data of the digital moving image A and the data of the digital moving image B recorded in the recording areas having different radial positions on the optical disk 17 are stored in the buffer memory 1.
The digital moving images A and B are successively input to the MPEG decoder 18 and decompressed, and are displayed as moving images on the monitor 19 without interruption at the joint between the digital moving images A and B.

The digital moving images A, B, and C are continuously reproduced, or the digital moving images C, B, and A are reproduced.
When performing continuous playback with the order changed as in
Similarly, if the necessary amount of digital moving image data is stored in the buffer memory 14 in advance during the access, and the digital moving image data in the buffer memory 14 is read out during the access, it is apparent that continuous reproduction can be performed. It is.

(Playback attempt when seek fails) Optical disc 1
Movement from one recording area to another recording area on the optical disk 17, that is, a seek operation may fail because the address information recorded on the disk 7 cannot be read. In such a case, the video disk device according to the present embodiment seeks again up to the retry count included in advance. Even during the retry seek, digital moving image data must be read from the buffer memory 14.

Here, the bit rate of the digital moving image data is assumed to be A (bps), and the maximum access time to the optical disk 17 (the optical disk 17 rotates once during the time when the optical head 16 seeks from the innermost circumference to the outermost circumference of the optical disk 17). If the storage capacity of the buffer memory 14 is A * S * (N11) bits or more, and the number of retries in case of seek failure is N, the seek restart By storing digital moving image data necessary for accessing the optical head 17 including the trial time in the buffer memory 14 in advance, the data can be read from the buffer memory 14 even during access, so that the moving image can be reproduced without interruption. Obviously you can do that. Here, the A * S * bits of the A * S * (N + 1) bits are for the first access, and the A * S * N bits are for the retry.

(Continuous reproduction using automatic disk changer)
In the above description, the capacity of the buffer memory 14 is assumed to be the amount of digital moving image data corresponding to the maximum access time to the optical disk 17, but the present invention is applied to a video disk device having an automatic disk changer capable of automatically changing the optical disk 17. When the present invention is applied, the optical disk 1
S2 is the sum of the maximum replacement time of 7 (the maximum time until the currently set optical disk can be replaced with the optical disk at the farthest position before recording and reproduction can be performed) and the maximum access time to the optical disk 17. When the bit rate of the digital video data is A (bps), the capacity of the buffer memory 14 may be A * S2 bits or more.

In this way, the digital moving image data necessary for the disk exchange time and the access of the optical head 16 are stored in the buffer memory 14 in advance, and the buffer memory is stored between the exchange time of the optical disk 17 and the access time of the optical head 16. Since the digital moving image data can be read out from the optical disk 14, it is clear that the image can be reproduced without interruption even when reproducing the digital moving image data recorded over a plurality of optical disks.

In consideration of the retry when the disk replacement fails and the retry when the seek fails, the maximum time of the disk replacement is S1 second, and the number of retries when the disk replacement fails is N.
1. Maximum access time to the optical head 16 (time obtained by adding the time required for the optical head 16 to make one rotation to the time required for the optical head 16 to seek from the innermost circumference to the outermost circumference).
Is S2 seconds and the number of retries in case of seek failure is N2, the storage capacity of the buffer memory 14 is A * S1 * (N1
+1) + A * S2 * (N2 + 1) bits or more.

With this arrangement, even if the optical disk 17 is exchanged and the optical head 16 is accessed again, the digital moving image data can be read from the buffer memory 14, so that the digital moving image data over a plurality of disks can be read. Images can be reproduced without interruption.

(Confirmation of Reproduced Image Predicted After Editing) Also, by using the function of continuously reproducing a plurality of moving images described above,
When editing moving image data recorded in a plurality of areas at different positions in the radial direction on the optical disk 17 and recording the same on the optical disk as one moving image data, a reproduced image expected after editing is continuously edited before editing. Can be played.
Therefore, editing can be confirmed in advance, and editing efficiency is improved.

Further, when editing a plurality of moving images in one disc using this function, a plurality of moving images can be edited according to the present invention without recording the edited moving image as one moving image data. It is clear that the moving image can be continuously reproduced just by editing the image by designating the reproduction order of the images, which is a simple editing function.

In the above embodiment, the present invention has been described as a recording / reproducing apparatus. However, the present invention can be applied to a reproduction-only video disk apparatus. In this case, as shown in FIG.
6, MPEG decoder 18, monitor 19, driver 2
1, a demodulator 22 and a controller 20.

The present invention can be applied not only to a video disk device but also to an audio disk device. In this case, as shown in FIG. 8, the audio disk device stores the digital audio signal from the digital audio signal circuit 41 in the buffer memory 42 and reads out the digital audio signal from the buffer memory 42, and outputs the digital audio signal to the speaker via the D / A converter 43. 44. The timing of the digital audio signal circuit 41 and the buffer memory 42 is controlled by a controller 45.
2 is controlled. With such a configuration, even if the reproduced audio signal of the digital audio circuit 41 is interrupted by the seek, sound can be continuously generated from the speaker. That is, the present invention can be applied to temporally continuous data such as moving image data and audio data.

In this embodiment, the case where the recording medium is an optical disk has been described. However, as long as data can be recorded / reproduced by a recording / reproducing head using a disk-shaped recording medium, the recording medium can be used in an original manner. For example, a magnetic disk device (hard disk device) or a floppy disk device may be used.

[0055]

As described above, according to the present invention, when reproducing digital moving image data recorded in regions at different positions on the disk in the radial direction in a predetermined order, the recording / reproducing head is used. Digital moving image data longer than the access time is reproduced from the recording medium in advance using the difference between the reproduction speed of the recording medium and the bit rate of the digital moving image data and stored in the buffer memory, and stored in the buffer memory during access. By reading and reproducing the read digital moving image data, a digital moving image is reproduced even during access, so that a digital moving image recorded in an area at an arbitrary position different in the radial direction on the disk is recorded and reproduced. It is possible to reproduce without interruption using the head.

[Brief description of the drawings]

FIG. 1 is a block diagram of a video disk device according to an embodiment of the present invention.

FIG. 2 is an exemplary view showing a recording area of each digital moving image on an optical disc in the embodiment.

FIG. 3 is a flowchart illustrating a recording operation of the video disk device of FIG. 1;

FIG. 4 is an exemplary view showing a change in moving image data amount in a buffer memory according to the embodiment;

FIG. 5 is an exemplary view showing a change in the content of moving image data in a buffer memory according to the embodiment;

FIG. 6 is a flowchart for explaining a reproducing operation of the video disk device of FIG. 1;

FIG. 7 is a block diagram of a video disk device according to another embodiment of the present invention.

FIG. 8 is a block diagram of an audio disc device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Analog image input part 12 ... MPEG encoder 13 ... Digital image input part 14 ... Buffer memory 15 ... Modulator / demodulator 16 ... Optical head 17 ... Optical disk 18 ... MPEG decoder 19 ... Monitor 20 ... Controller 21 ... Driver 22 ... Demodulator 31; 32, 33 ... recording area

Claims (6)

[Claims] 1. A disk device for recording and reproducing digital continuous data by a recording / reproducing head using a disk-shaped recording medium, comprising: a buffer memory for temporarily storing digital continuous data reproduced from the recording medium; Control means for performing control for sequentially reproducing digital continuous data recorded in a plurality of areas having different radial positions on the recording medium in a predetermined order, the control means comprising: Digital read / write data for a time equal to or longer than the access time between the plurality of areas of the read / write head is played back at a higher speed than the bit rate of the digital read / write data and stored in the buffer memory; During and during the access time, the digital sequence stored in the buffer memory. Disk apparatus characterized by continuously performing read and controlled to play over data. 2. A bit rate of the digital continuous data is A (bps), a maximum access time to the recording medium (a seek time required for the recording / reproducing head to move from the innermost circumference to the outermost circumference of the recording medium). 2. The disk device according to claim 1, wherein the storage capacity of the buffer memory is A * S bits or more, where S is the time obtained by adding the time required for the recording medium to make one rotation. 3. A bit rate of the digital continuous data is A (bps), a maximum access time to the recording medium (a seek time required for the recording / reproducing head to move from the innermost circumference to the outermost circumference of the recording medium). The storage capacity of the buffer memory is at least A * S * (N + 1) bits, where S is the time obtained by adding the time required for the recording medium to make one rotation, and N is the number of retries in case of a seek failure. 2. The disk device according to claim 1, wherein: 4. A function of automatically exchanging the recording medium, wherein a maximum time required for exchanging the recording medium and a maximum access time to the recording medium (when the recording / reproducing head is moved from the innermost circumference of the recording medium to The sum of the seek time required to move to the outermost circumference and the time required for the recording medium to make one revolution) is S seconds, and the bit rate of the digital continuous data is A.
2. The disk device according to claim 1, wherein the storage capacity of the buffer memory is A * S bits or more when (bps). 5. A function for automatically exchanging the recording medium, wherein the maximum time required for exchanging the recording medium is S1 second, the number of retries when the exchanging of the recording medium fails is Nl, The access time (the seek time required for the recording / reproducing head to move from the innermost circumference to the outermost circumference of the recording medium plus the time required for the recording medium to make one rotation) is S2 seconds, and a retry in case of a seek failure When the number of times is N2 and the bit rate of the digital continuous data is A (bps), the storage capacity of the buffer memory is set to A * S1 * (N11) 10A * S2 * (N2 + 1) bits or more. 2. The disk device according to claim 1, wherein: 6. The control means edits continuous digital data recorded in an arbitrary area among a plurality of areas having different radial positions on the recording medium and records the digital continuous data as one digital image on the recording medium. 2. The method according to claim 1, further comprising the step of controlling to continuously reproduce digital continuous data, which is to be an expected reproduced image after editing, before editing.
The disk device according to item 1.