JPH03185631A - Optical disk and optical disk reproducing device - Google Patents

Abstract

PURPOSE:To dialogically selectively perform a reproducing operation by dividing individual reproducing tracks capable of reproducing a signal simultaneously from at least two tracks or more into sectors, recording each sector with a video signal, an audio signal and a character and graphic signal after time- division multiplexing and changing the signals of the individual sectors. CONSTITUTION:A 1st optical head 18 and a 2nd optical head 19 are capable of reproducing a signal simultaneously and parallel from two adjacent tracks. Feeble signals from the optical heads 18 and 19 are amplified and binarized to be converted into digital signals by analog signal processing parts 20 and 21, and their outputs are inputted to a data signal processor 3 for processing a data signal such as characters and graphics, etc., an audio processor 4 for processing an audio signal and a video processor 5 for processing a video signal. Each data is sent by each processor to a controller 6, where the video signal, audio signal and character and graphic signal are dialogically changed by the controller 6 from program software or an operator's operation with a mouse 8. By this method, the reproducing under dialogical selection is feasible.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is expected to be applied to educational multimedia systems, etc., and selectively reproduces multimedia such as video signals, audio signals, single character graphic signals, etc. The present invention relates to an optical disc and an optical disc playback device.

BACKGROUND OF THE INVENTION FIG. 4 shows a conventional multimedia playback system. 1 is an optical disk drive, and 2 is an optical disk in a mounted state. Signals reproduced from the optical disk drive 1 are input to a data signal processor 3 that processes data signals such as characters and graphics, an audio processor 4 that processes audio signals, and a video processor 5 that processes video signals. Each processor outputs data to the controller 6 according to instructions from the controller 6.

The controller 6 interactively switches and selects a video signal, an audio signal, and a two-character graphic signal by operating the program software or the mouse 8 by the operator.

images can be played back on the monitor 7 while

FIG. 5 shows the screen display of the monitor 7. Audio comes first
Playback is performed through the speaker 9 while selecting the 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 at 30 frames per second. Video signals are 5th channel 11, 6th channel 1
2 are simultaneously displayed on the monitor 7 by the program software, or are selectively displayed. The fifth channel is a high-quality reduced screen with about 1/4 the number of pixels of the BTA high-visigon standard. Here, the monitor 7 is a 30 to 40 inch high-visibility monitor. The 6th channel is a medium-quality reduced screen with about 1/4 the number of pixels of the NTSC standard. 13 is channel control graphics and text data 10
Similarly, data is read from the third and fourth channels. Click on the graphic 13 (icon) etc. of the channel number you wish to display on the screen using the mouse 8 to select it. In this way, with the educational software, the operator interactively selects channels for video signals, audio signals, single character graphic signals, and plays back the contents of the optical disc playback device according to the instructions on the screen and the level of understanding. You can learn while doing it.

FIG. 6 shows a recording format of an optical disc in which sectors are time-division multiplexed to realize a monitor display as shown in FIG. 14 represents the sector number, and 15 represents the contents of the sector. A represents an audio signal, D represents a data signal, and ■ represents a video signal, which is a moving image at 30 frames per second. In this format, a total of 18 sectors, with sector numbers O to 17, form one group. For example, the l group is a video signal that is time-division multiplexed with video data for one frame of video signals of the fifth and sixth channels, an audio signal, and a character/graphic signal that is played along with this one frame. The fifth channel of the signal is sector number 4~
9 stores image data of 6 sectors per frame. The accompanying audio data is stored in sector number O for the first channel and sector number 1 for the second channel, and either the first channel or the second channel is selected by the operator or program software. Furthermore, the data of the accompanying character/graphic signals are stored in sector number 2 for the third channel and sector number 3 for the fourth channel, and the operator or program software similarly selects either the third channel or the fourth channel. 6th video signal
In the channel, video data is stored in sector numbers 14 to 17, and audio signals and audio signals are stored in sector numbers 10 to 13.
Stores and selectively displays character and graphic signal data.

Problems to be Solved by the Invention In order to store data in the time division multiplex format as shown in Figure 6, the video signal (moving image at 30 frames per second) and audio signal must be recorded with high efficiency encoding and time compressed. There must be.

In order to ensure a playback time of about 60 mm for high-quality reduced videos like the 5th channel, the outer diameter of the optical disc must be 30 mm.
cm is required. First, the recording data rate of the optical disc to ensure a playback time of 60 minutes is calculated. Consider a playback-only optical disc. Commercially available CD-ROM
Based on the recording density of , assuming that the laser wavelength of the reproduction light for reading the signal is 670 nm, and the N and A of the aperture lens are 0.55, one side of a 30 cm optical disc will have 9 gigabytes) (9G
B) user data can be recorded. If the playback time is 60 minutes, the recording data rate is 20 Mbps.

On the other hand, the fifth channel is a high-quality reduced video, with the number of pixels reduced by about 1/4 of the BTA high-definition standard. That is, each R/G/B screen has 512/1024 pixels. If sampling is 8 bits per pixel, then 3 bits per second.
The data rate when sampling a 0 frame video is:
It becomes 377Mbps.

Next, we will calculate how much a high-quality reduced video at 30 frames per second must be compressed to be able to be played on a 30 cm optical disc for 60 minutes. The fifth channel stores image data that is time-division multiplexed 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 is 20 Mbps when the playback time is 60 minutes, the compression ratio is as follows. The number in parentheses represents the compression rate within the frame.

377Mbps+20MbpsX(18/6)=57 original sampled data must be compressed to 1157.

However, with the above configuration, there is a problem that it is extremely difficult to compress a high-quality moving image to 1157 while maintaining the image quality to some extent. Even if it could be realized, the amount of bars would be so large that it would be impossible to popularize it as an educational application. Moreover, the image quality deteriorates significantly, making it impossible to effectively function as an educational application. In order to overcome these problems, we recorded high-quality moving images on optical discs by time-division multiplexing them together with audio signals and text/graphic signals.
It has been impossible to realize a device that reproduces the content while selecting it interactively.

The present invention records high-quality moving images on an optical disk by time-division multiplexing them together with audio signals and character/graphic signals at a compression rate that is relatively easy to implement in hardware while maintaining high image quality. It is an object of the present invention to provide an optical disc and an optical disc reproducing device that can be reproduced while making interactive selections.

Means for Solving the Problems In order to achieve the above object, the optical disc and optical disc reproducing apparatus of the present invention are capable of simultaneously reproducing signals from at least two or more trunks in a disc-shaped recording medium, and each reproduction track is divided into sectors,
Video signal for each sector.

To provide an optical disc having a format in which an audio signal and a two-character graphic signal are time-division multiplexed and recorded, and the signals of each sector can be switched and reproduced while being selected.

In addition, in at least two or more tracks to be played simultaneously, only a video signal is recorded in each sector of (1) or multiple tracks, and video signals and
To provide an optical disc having a format in which an audio signal and a nine-character graphic signal are time-division multiplexed and recorded, and the signals of each sector can be switched and reproduced while being selected.

Furthermore, the present invention provides an optical disc reproducing apparatus having a means for switching and selectively reproducing signals of each sector on an optical disc having the above format.

Operation The present invention uses the above-described configuration to maintain high image quality and record high-quality moving images on an optical disk by time-division multiplexing them together with audio signals and character/graphic signals at a compression rate that is relatively easy to implement in hardware. , it is possible to provide an optical disc and an optical disc reproducing device that can reproduce the content while interactively selecting it.

Embodiment FIG. 1 shows the configuration of an optical disc reproducing apparatus in an embodiment of the present invention. 2 is an optical disk; 17 is a spindle motor for rotating the optical disk 2; 18 is a first optical head, and 19 is a second optical head, which are optical nodes capable of reproducing signals from two adjacent tracks simultaneously and in parallel.

20.21 is an analog signal processing section, and optical head 18 1
Amplifying the weak signal from 9 and converting it to a digital signal 2
Perform value conversion. The output of the analog signal processing unit 2021 is a data signal processor 3 that processes data signals such as characters and graphics, an audio processor 4 that processes audio signals,
The video signal is input to a video processor 5 that processes the video signal.

Each processor sends data to the controller 6 according to instructions from the controller 6. The controller 6 can interactively switch between a video signal, an audio signal, and a single character/graphic signal by using program software or the operator's operation of a mouse 8, and can reproduce an image on the monitor 7 while making a selection.

The screen display on the monitor 7 is similar to that shown in FIG. 5 of the conventional example. Audio 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 at 30 frames per second. As for the video signal, the fifth channel 11 and the sixth channel 12 are displayed on the monitor 7 simultaneously or selectively by program software. The fifth channel is a high-quality reduced screen with a pixel count of about 174 according to the BTA high-definition standard. Here, the monitor 7 is a 30- to 40-inch high-definition monitor, and the sixth channel is a medium-quality reduced screen with about 1/4 the number of pixels of the NTSC standard. Reference numeral 13 denotes graphics for channel control, and like the text data 10, data is read from the third and fourth channels. Select the graphics 13 (icon) of the channel number you wish to display on the screen using the mouse 8. In this way, with educational application software, the operator interacts with video signals according to the instructions on the screen and their level of understanding.

It is possible to learn by selecting the channel of the audio signal and the two-character graphic signal and reproducing the contents on the optical disc reproducing device.

Figures 2(a) and (b) show an optical disc of the present invention in which sectors are time-division multiplexed using two optical heads in order to realize the monitor display as shown in Figure 5 without increasing the compression ratio. It is a recording format. 22 is the first light head 18
the signal format of the first regenerated trunk regenerated from;
23 is the signal format of the second reproduction track reproduced from the 7th field 19 to the second light. 22 and 23 are reproduced simultaneously and in parallel from the light beams 18 and 19 on the same time axis.

14 represents the sector number, and 15 represents the contents of the sector. A represents an audio signal, D represents a data signal, and ■ represents a video signal, which is a moving image at 30 frames per second. 18 sectors
They form one group. 1 group is 3 per second
Represents the time for one frame of a 0-frame video. The signal reproduced from the first optical head is entirely occupied by high-quality video data of the fifth channel in 1 group (18 sectors). On the other hand, 1 is reproduced from the second optical head.
The signals in the group are a medium-quality video for 1 frame of the 6th channel, an audio signal played along with 1 frame of the video signal of each of the 5th channel and the 6th channel, and 1 character/graphic signal that is time-divided. It's multiplexed. For example, the fifth channel of the video signal is sector number 0 of the first optical head.
17 store image data of 18 sectors per frame. As for the audio signal associated with the fifth channel, the audio data of the first channel is stored in sector number O of the second optical node, and the audio data of the second channel is stored in sector number 1. Either the first channel or the second channel is selected by the operator or the program software. Furthermore, the accompanying character/figure signal transmits the data of the third channel to sector number 2 of the second optical head, and the data of the third channel to sector number 3 of the second optical head.
The fourth channel data is stored in . Similarly, the operator or the program software selects whether the character/figure signal is to be sent to the third channel or the fourth channel. The video signal for medium-quality video is from sector numbers 8 to 1 of the 6th channel of the 2nd optical head.
7 stores video data, and sector numbers 4 to 7 similarly store audio signal and text/graphic signal data for selective display.

If all the image data of a high-quality moving image is stored in the first playback track 22 in this way, the entire time of one frame is image data and is not time-division multiplexed with audio signals or text/graphic signals, as in the conventional example. There is no need for further data compression within the frame.

Therefore, the compression ratio of time is as follows. The numbers in parentheses represent data compression within the frame.

377Mbps+20MbpsX (18/18)=1
8 In the conventional example, data was further compressed by 1/3 within the frame, resulting in a compression ratio of 1157, which was difficult to implement in hardware, but it is possible to achieve this in about 1/1 day. There is gender. By simply reducing the number of playback tracks to two, the compression rate of image data can be improved to 1/3. Therefore, it is possible to time-division multiplex high-quality video with audio signals and text/graphic signals, record it on an optical disk, and play it back while selecting the contents interactively. An optical disc and an optical disc playback device can be provided. In FIG. 3, a groove-shaped guide track is provided on the optical disc 2, and the signal of the first reproduction track 22 is transmitted to the first slope 24 of the groove shape, and the signal of the second reproduction track 23 is transmitted to the second slope 25 of the groove. This is how the signal is recorded in the form of bits. ■If a groove-shaped guide trunk is provided, theoretically there will be 2 points in the trunk direction compared to when it is not provided.
It is possible to double the recording density. Therefore, if you play back the optical disc 2, which has the keyakin V-groove-shaped guide track shown in Figure 3 and recorded signals, you can compress the image data without shortening the playback time even with an optical disc of the same outer diameter. 1/3
can be improved. ■If you use an optical disc with a groove-shaped guide trunk, you can time-division multiplex high-quality video with audio signals and text/graphic signals without shortening the playback time. It is possible to provide an optical disc and an optical disc reproducing apparatus that can record information on an optical disc and reproduce the content while interactively selecting the content.

As described above, according to the present invention, high-quality moving images can be time-division multiplexed with audio signals and text/graphic signals at a compression rate that is relatively easy to implement in hardware while maintaining high image quality. It is possible to provide an optical disc and an optical disc playback device that can record data on an optical disc and play back while interactively selecting the contents.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an optical disc reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a diagram of an optical disc recording format of the embodiment, and FIG. 3 is an explanatory diagram showing the track shape of the embodiment.
Fig. 4 is a configuration diagram of a conventional optical disc reproducing device, and Fig. 5 is a diagram showing the display of the present invention.
8...First optical head, 19...Second optical head.

Claims (6)

[Claims] (1) In a disk-shaped recording medium, it is possible to simultaneously reproduce signals from at least two or more tracks, each reproduction track is divided into sectors, and video signals, audio signals, and text/graphic signals are time-division multiplexed for each sector. An optical disc that has a format that allows for recording, switching the signals of each sector, and playing back while selecting. (2) The optical disc according to claim (1), wherein each of the video signal, audio signal, and text/graphic signal for each sector is composed of at least two or more channels, and has a format that allows playback while switching and selecting channels. (3) In at least two or more tracks that are played back simultaneously, only a video signal is recorded in each sector of one or more tracks, and the other playback tracks are recorded with video signals and
2. The optical disc according to claim 1, wherein the optical disc has a format in which audio signals and character/graphic signals are time-division multiplexed and recorded, and the signals of each sector can be switched and reproduced while being selected. (4) In a video signal composed of at least two or more channels, one channel of the video signal is distributed to each of at least two trunks that are played simultaneously, and audio signals and text/graphic signals are time-division multiplexed. 2. The optical disc according to claim 1, wherein the optical disc has a format that allows recording, switching and selectively reproducing signals of each sector. (5) The optical disc according to claim (1), wherein the optical disc has a format that allows simultaneous reproduction of signals recorded on both slopes of each of the V-shaped guide grooves formed on the disc-shaped recording medium. (6) It is possible to simultaneously reproduce signals from at least two or more tracks, and each reproduction track is divided into sectors,
Optical disc reproduction comprising means for switching and selectively reproducing the signals of each sector in the optical disc according to claim (1), which has a format in which video signals, audio signals, and text/graphic signals are time-division multiplexed and recorded for each sector. Device.