JP2697209B2 - Optical disk signal recording method and optical disk reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATION The present invention is expected to be applied to a multimedia system for education and the like.
The present invention relates to an optical disk signal recording method for performing time-division recording of multimedia such as a character / graphic signal and an optical disk reproducing apparatus.

FIG. 4 shows a conventional system capable of reproducing multimedia. Reference numeral 1 denotes an optical disk drive, and reference numeral 2 denotes a mounted optical disk. The signal reproduced from the optical disk drive 1 is input to a data signal processor 3 for processing data signals such as characters and figures, an audio processor 4 for processing audio signals, and a video processor 5 for processing video signals. Each processor sends data to the controller 6 according to a command from the controller 6. The controller 6 is provided with a video signal, an audio signal,
An image can be reproduced on the monitor 7 while the character / graphic signal is interactively switched and selected.

FIG. 5 is a screen display of the monitor 7. The audio signal is reproduced from the speaker 9 while selecting the first channel and the second channel. The text data 10 is reproduced while selecting the third channel and the fourth channel, and displayed on the monitor 7. The video signal is a moving image of 30 frames per second. The video signal is the fifth channel 11 and the sixth channel 12
Are simultaneously displayed on the monitor 7 by the program software or are selectively displayed. The fifth channel is a high-quality reduced screen and has about 1/4 the number of pixels of the BTA HDTV standard. Here, the monitor 7 uses a 30 to 40 inch high-vision monitor. The sixth channel is a reduced screen of medium quality and has about 1/4 the number of pixels of the NTSC standard. Reference numeral 13 denotes channel control graphics, which are read out from the third and fourth channels in the same manner as the text data 10. Graphics of the channel number you want to display on the screen with the mouse 8
13 Click (icon) etc. to select. As described above, in the educational application software, the operator interactively selects the video signal, the audio signal, and the character / graphic signal channel according to the screen instructions and the degree of understanding, and reproduces the contents of the optical disk reproducing device. You can learn.

FIG. 6 shows a recording format of an optical disk in which sectors are time-division multiplexed to realize monitor display as shown in FIG. 14 indicates the sector number, and 15 indicates the contents of the sector. A represents an audio signal, D represents a data signal, and V represents a video signal, which is a moving image of 30 frames per second. In this format, one group is formed by a total of 18 sectors, sector numbers 0 to 17. One group is time-division multiplexed with video data for one frame of the video signals of the fifth and sixth channels, and audio signals and character / graphic signals reproduced along with the one frame. For example, the fifth channel of the video signal stores image data of 6 sectors per frame in sector numbers 4 to 9. As for the accompanying audio signal, the first channel has sector number 0,
The second channel stores audio data in sector number 1 and selects the first channel or the second channel by an operator or program software. Further, the accompanying character / graphic signal is such that the third channel is assigned to sector number 2,
The channel stores data in sector number 3, and similarly selects the third channel or the fourth channel by an operator or program software. The sixth channel of the video signal stores video data in sector numbers 14 to 17,
Similarly, data of audio signals and character / graphic signals are stored in 10 to 13 and selectively displayed.

Problems to be Solved by the Invention In order to store data in a time-division multiplex format as shown in FIG. 6, a video signal (moving image of 30 frames per image) and an audio signal are encoded and recorded with high efficiency, and time compression is performed. Must.

The outer diameter of the optical disc should be 30cm to ensure the playback time is about 60 for high quality reduced video like channel 5.
is necessary. First, the recording data rate of the optical disc for securing the reproduction time of 60 minutes is calculated. Consider a read-only optical disk. Based on the recording density of a commercially available CD-ROM, the laser wavelength of the reproduction light for reading signals is 670 nm,
If the aperture lens has an NA of 0.55, 9 gigabytes (9 GB) of user data can be recorded on one side of a 30 cm optical disc. If the playback time is 60 minutes, the recording data rate is 20Mb
ps.

On the other hand, the fifth channel has a reduced number of pixels of about 1/4 of the high-resolution reduced moving image and the high definition BTA standard. That is, each R / G / B screen has 512/1024 pixels. Assuming that the sampling is 8 bits per pixel, the data rate at the time of sampling a moving image of 30 frames per second is 377 Mbps.

Next, it is calculated how much compression of a high-quality reduced moving image of 30 frames per second can be reproduced on a 30 cm optical disk for 60 minutes. The fifth channel stores image data by time division multiplexing into 6 sectors per 18 sectors per frame. Therefore, the amount of image data per frame must be compressed to 1/3. Since the recording data rate when the reproduction time is 60 minutes is 20 Mbps, the compression ratio is as follows. ()
The inside indicates the compression ratio in the frame.

377Mbps ÷ 20Mbps × (18/6) = 57 Original sampling data must be compressed to 1/57.

However, the above configuration has a problem that it is extremely difficult to compress a high-quality moving image by 1/57 while maintaining the image quality to some extent. Even if it can be realized, the amount of hardware will be enormous, and it is impossible to spread it as an educational application. Moreover, the image quality is significantly deteriorated, and the function cannot be effectively exhibited as an educational application. Because of these problems, it is impossible to realize a device that records time-division multiplexing of a high-quality moving image together with an audio signal and a character / graphic signal on an optical disc and interactively selects and reproduces the content. Was.

According to the present invention, a high-quality moving image is time-division multiplexed with an audio signal and a character / graphic signal and recorded on an optical disk at a compression ratio that is relatively easy to realize while maintaining high image quality. It is an object of the present invention to provide an optical disk and an optical disk reproducing device capable of displaying a screen while interactively selecting the optical disk.

Means for Solving the Problems In order to achieve the above object, the present invention comprises a plurality of reproduction tracks that can be reproduced at least two at the same time during reproduction, and each reproduction track is divided into sector areas having substantially the same data capacity. In the area, a video signal and an audio signal and at least one signal of a character / graphic signal which have been binarized and modulated by the same digital modulation code are recorded in sector units. On the other track, only the video signal is continuously arranged in sector units, and in the other reproduction tracks, the video signal and at least one of the audio signal and the character / graphic signal are time-divisionally recorded in sector units. Provided is a signal recording method.

Also, a plurality of optical head signals are reproduced from the optical disk having the above-mentioned format, and a video signal and an audio signal and / or a character / graphic signal which are reproduced from the other reproduction tracks and processed are selectively output. Provided is an optical disk reproducing apparatus configured to switch and display a drawing.

The present invention maintains high image quality by the above-described configuration,
A high-quality video can be time-division multiplexed with audio signals and text / graphic signals and recorded on an optical disc with a compression ratio that is relatively easy to implement with hardware, and the contents can be displayed interactively on the screen. It is possible to provide a large number of optical disks and an optical disk reproducing apparatus.

Embodiment FIG. 1 shows a configuration of an optical disk reproducing apparatus according to an embodiment of the present invention. Reference numeral 2 denotes an optical disk, and 17 denotes a spinned motor for rotating the optical disk 2. 18 is the first
An optical head 19 is a second optical head, which is capable of reproducing signals from two adjacent tracks simultaneously and in parallel. 20, 21 are analog signal processing units, and optical heads 18,
Amplify weak signal from 19 or convert to digital signal 2
Perform value conversion. The outputs of the analog signal processing units 20 and 21 are a data signal processor 3 for processing data signals such as characters and figures, an audio processor 4 for processing audio signals,
The video signal is input to a video processor 5 for processing the video signal.
Each processor sends data to the controller 6 according to a command from the controller 6. The controller 6 can interactively switch between a video signal, an audio signal, and a character / graphic signal by operating the mouse 8 by the program software or the operator, and can reproduce an image on the monitor 7 while selecting the signal.

The screen display on the monitor 7 is the same as that of the conventional example shown in FIG.
The audio signal is reproduced from the speaker 9 while selecting the first channel and the second channel. Text data
Numeral 10 reproduces while selecting the third and fourth channels, and displays them on the monitor 7. The video signal is a moving image of 30 frames per second. As the video signal, the fifth channel 11 and the sixth channel 12 are simultaneously displayed on the monitor 7 by the program software or are selectively displayed. The fifth channel is a high-quality reduced screen and has about 1/4 the number of pixels of the BTA HDTV standard. Here, the monitor 7 uses a 30 to 40 inch high-vision monitor. The sixth channel is a reduced screen of medium quality and has about 1/4 the number of pixels of the NTSC standard. Reference numeral 13 denotes graphics for channel control, in which data is read from the third and fourth channels in the same manner as the text data 10. Click and select the graphics 13 (icon) of the channel number to be displayed on the screen with the mouse 8. In this way, in the application software for education, the operator interactively responds to the video signal,
Learning can be performed while selecting the channel of the audio signal and the character / graphic signal and reproducing the contents of the optical disk reproducing apparatus.

FIGS. 2 (a) and 2 (b) show an optical disk of the present invention in which sectors are time-division multiplexed using two optical heads in order to realize a monitor display as shown in FIG. 5 without increasing the compression ratio. This is a recording format. Reference numeral 22 denotes a signal format of a first reproduction track reproduced from the first optical head 18, and reference numeral 23 denotes a signal format of a second reproduction track reproduced from the second optical head 19. 22,23 have the same time axis and the optical head 18,
Played simultaneously and in parallel from 19. 14 indicates the sector number, and 15 indicates the contents of the sector. A represents an audio signal, D represents a data signal, and V represents a video signal, which is a moving image of 30 frames per second. A group is formed by 18 sectors. One group represents the time for one frame of a moving image of 30 frames per second. The signals reproduced from the first optical head are all occupied by video data of high-quality moving images of the fifth channel in one group (18 sectors). While the second
The signals in one group reproduced from the optical head are a medium-quality moving image for one frame of the sixth channel, and an audio signal and a character reproduced along with one frame of the video signal of each of the fifth and sixth channels. Graphic signals are time-division multiplexed. For example, in the fifth channel of the video signal, the sector numbers 0 to 17 of the first optical head all correspond to one frame.
Stores 18 sectors of image data. The audio signal associated with the fifth channel is the sector number 0 of the second optical head.
And the audio data of the first channel to sector number 1
To store the audio data of the second channel. 1st channel or 2nd channel by operator or program software
Select a channel. Further, the accompanying character / graphic signal stores the data of the third channel in the sector number 2 of the second optical head, and stores the data of the fourth channel in the sector number 3 of the second optical head. Similarly, the operator or the program software selects the third or fourth channel for the character / graphic signal. For the video signal of the medium quality moving image, the video data is stored in sector numbers 8 to 17 of the sixth channel of the second optical head, and the audio signal and character / graphic signal data are similarly stored and selected in sector numbers 4 to 7. indicate.

If all the image data of a high-quality moving image is stored in the first reproduction track 22 in this manner, the entire image data is not axis-division multiplexed with the audio signal or the character / graphic signal within the time of one frame. There is no need for further data compression within the frame. Therefore, the compression ratio is as follows. ()
In the figure, the data compression ratio in the frame is shown.

377Mbps ÷ 20Mbps x (18/18) = 18 In the conventional example, data compression was further reduced by 1/3 in the frame, so the compression ratio became 1/57, making it difficult to implement hardware. If it is about 1/18, there is a possibility. The compression ratio of the image data can be improved to 1/3 only by using two reproduction tracks. Therefore, it is possible to time-divisionally multiplex a high-quality moving image having higher image quality and a possibility of realizing hardware with an audio signal or a character / graphic signal and record it on an optical disk, and reproduce the contents while interactively selecting the contents. An optical disk and an optical disk reproducing device can be provided. FIG. 3 shows that the optical disk 2 is provided with a V-groove-shaped guide track, and the first slope 24 of the V-groove is provided with a first
This is a state where the signal of the reproduction track 22 is recorded in the pit shape on the second slope 25.
If a V-groove-shaped guide track is provided, the recording density can be theoretically doubled in the track direction as compared with the case where no guide groove is provided. Therefore, if the optical disk 2 on which a signal is recorded by providing a V-groove-shaped guide track as shown in FIG.
Even with an optical disc having the same outer diameter, the compression ratio of image data can be improved to 1/3 without reducing the reproduction time. Using an optical disk provided with V-groove-shaped guide tracks, time-division multiplexing of high-quality moving images with higher image quality and the possibility of hardware realization with audio signals and character / graphic signals without reducing the playback time An optical disk and an optical disk reproducing apparatus capable of recording on an optical disk and reproducing the contents while interactively selecting the contents are possible.

As described above, according to the present invention, while maintaining high image quality, a high-quality moving image is time-division multiplexed with an audio signal and a character / graphic signal at a compression ratio that is relatively easily realized by hardware. An optical disk and an optical disk reproducing apparatus capable of recording the information on an optical disk and displaying the screen while interactively selecting the contents can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an optical disc reproducing apparatus according to an embodiment of the present invention, FIG. 2 is an optical disc recording format diagram of the embodiment, FIG. 3 is an explanatory diagram showing a track shape of the embodiment,
FIG. 4 is a configuration diagram of a conventional optical disk reproducing apparatus, FIG. 5 is a configuration diagram showing a display example of a display of the present invention, and FIG. 6 is a recording format diagram of a conventional optical disk. 2 ... optical disk, 18 ... first optical head, 19 ... second optical head.

Claims (2)

(57) [Claims] A reproduction track is provided which can reproduce a plurality of at least two tracks at the same time during reproduction. Each reproduction track is divided into sector areas having substantially the same data capacity, and the sector areas are binarized by the same digital modulation code. At least one of the video signal, audio signal, and text / graphic signal
Of the plurality of tracks that can be simultaneously reproduced, at least a video signal is continuously arranged in a sector unit on at least a first track, and a video signal is arranged on the other reproduction tracks. A signal recording method for an optical disc, wherein an audio signal and at least one signal of a character / graphic signal are time-divisionally recorded in sector units. 2. A method according to claim 1, wherein at least two tracks are reproduced at the same time during reproduction. Each reproduction track is divided into sector areas having substantially the same data capacity, and said sector areas are binarized by the same digital modulation code. At least one of the video signal, audio signal, and text / graphic signal
Of the plurality of tracks that can be simultaneously reproduced, at least a video signal is continuously arranged in a sector unit on at least a first track, and a video signal is arranged on the other reproduction tracks. From an optical disc having a format in which an audio signal and at least one signal of a character / graphic signal are time-divisionally recorded in sector units,
A plurality of optical head signals are reproduced, and a video signal reproduced and processed from at least one of the other reproduction tracks and at least one of an audio signal and a character / graphic signal are selectively switched to be displayed in a drawing. Optical disc playback device.