JPH0798890A - Medium, method and device for recording optical disk - Google Patents

Abstract

PURPOSE:To remarkably improve the recording density of an optical disk and to enable long-time recording by using an optical pickup of a shorter wavelength laser as a light source. CONSTITUTION:In the optical disk recording medium with the diameter less than 130mm to which moving picture information is recorded, the track pitch is 0.7 to 0.9mum, the recording line density is 0.18 to 0.25mum/bit, and the disk recording area is larger than radial 20mm and less than 65mm, and the line speed is 3.3 to 5.3m/sec, and the pit shape is embossed pit and the base width is 1.2+ or -0.1mm. The recording medium is reproduced by using the optical pickup having the characteristic with the objective lens numerical aperture 0.6 and with space shielding frequency of 2067mm. The data read out from a disk is stored in a buffer memory of one circle of the outermost peripheral of the disk. According to the remaining amount of the data, the reading from the disk is temporarily stopped and a variable length encoded moving image voice signal is reproduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc recording medium obtained by recording a moving image signal having an image quality equivalent to that of commercial broadcasting as a digital signal on an optical disc having a small diameter (about 12 cm) which is excellent in operability. The present invention relates to an optical disc recording method for recording and an optical disc reproducing apparatus for reproducing this optical disc.

[0002]

2. Description of the Related Art Conventionally, there is known a system in which a moving image signal having an image quality equivalent to that of a commercial broadcast is recorded on an optical disc and the disc provides entertainment such as movies. An example of such a system is a so-called LD (laser disk)
Systems are well known. In an optical video disc such as this so-called LD, a video signal of about 1 hour and two-channel (left and right) audio signals can be recorded on an optical disc having a diameter of 30 cm.

On the other hand, in the concept of recording a digital signal, a so-called CD (compact disc) system is well known. In this CD, a maximum of 2/4 channel (left and right) digital audio signals are recorded on an optical disc having a diameter of 12 cm. The data rate of digital signals in this CD (compact disc) system is 1.4 Mbps. Since this CD is an optical disk with a diameter of 12 cm, it has excellent storage and portability, and because it uses extremely few materials, it can be said that it is resource saving.

On the other hand, a method of reducing the data rate by high-efficiency coding of an image signal is well known. For example, MP
The standardization proposal by EG (Moving Picture Experts Group) 1 defines a so-called high-efficiency coding method for image signals for so-called digital storage media.

[0005]

In the so-called LD described above, since the disk has a diameter of 30 cm, it lacks in storability and portability, and requires many materials in terms of resources.

For the above-mentioned CD, this diameter is 12
So-called LD on the centimeter optical disc
In actuality, it is difficult to record a video signal of about 1 hour and an audio signal of 2 channels (left and right) similar to the system. That is, the digital video signal has a data rate of 100 to 200 Mbps (Mega
Therefore, it is clear that an optical disc having a diameter of 12 cm, which is the same as a CD, can record a moving image of at most 60 to 120 seconds.

Further, a storage medium targeted for a method of lowering a data rate by highly efficient encoding of an image signal like MPEG1 is a so-called CD.
(Compact disc), DAT (digital audio tape recorder), hard disc, etc., the data rate of which is about 1.5 Mbps or less. Therefore, it cannot be said that the technology proposed or put into practical use can obtain a sufficient image quality because of the low data rate.

The present invention has been made in view of the above situation, and a moving image signal having an image quality equivalent to that of a commercial broadcast is used as a digital signal, and the image quality is not deteriorated on a small-diameter disc having excellent operability, and An object is to provide an optical disc recording medium capable of realizing long-term recording, an optical disc recording method for recording this optical disc, and an optical disc reproducing device for reproducing this optical disc.

[0009]

In order to solve the above problems, an optical disk recording medium according to the present invention is an optical disk recording medium having a diameter of 130 mm or less on which moving image information is recorded and has a track pitch of 0. 7-0.9 μm, recording linear density 0.18-0.25 μm / bit, radius of disk recording area is 20 mm or more and less than 65 mm from center, linear velocity 3.3-5.3 m / sec, pit shape is embossed pit And the substrate thickness satisfies the conditions of 1.2 ± 0.1 mm.

Further, the optical disk recording method according to the present invention solves the above problems by recording and forming an optical disk recording medium satisfying the above conditions.

Here, the moving image is obtained by compressing an image of one frame to 2 Mbit or less, and the compressing method divides a predetermined number of pixels into blocks, and uses motion prediction and DCT (discrete cosine transform) for each block. As the compression method, the motion estimation and the DCT are used by adaptively changing the quantization roughness or the like in frame units, field units, slice units, and block units according to the image quality of the original image. .

Further, the present invention is characterized in that a compression encoding method is used in which an audio signal is divided into blocks by a predetermined time unit and bits are assigned to the spectrum of each block according to human auditory characteristics.

Further, in the optical disk reproducing apparatus according to the present invention, the optical disk recording medium satisfying the above conditions is an objective lens numerical aperture of 0.6 or less and a spatial cutoff frequency of 2067 lines / m.
The above problem is solved by reproducing by using an optical pickup having a characteristic of m or more.

Further, the optical disk reproducing apparatus according to the present invention stores the data read from the disk in the buffer memory for one outermost circumference of the disk and temporarily stops the reading from the disk according to the remaining amount of the data. Thus, the above problem is solved by reproducing the moving image audio signal that has been encoded in the variable length.

[0015]

Since the moving image and the voice are recorded by using the optical pickup which uses the short wavelength laser having the characteristics of high focusing accuracy and low noise as the light source, the recording density of the optical disk can be greatly improved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. 1 and 2 show an overall schematic block diagram of this embodiment. First, a schematic configuration of the data encoding device will be described with reference to FIG. In FIG. 1, as a video signal, a luminance signal Y, color difference signals RY and BY are input to the A / D converter 101, converted into a digital video signal and output. Thereafter, in the signal compression unit 102, motion detection, motion compensation, DCT (discrete cosine transform), etc., which will be described later, are performed, and the result is stored in the video code buffer memory 103.

Similarly, two left and right channels (in FIG. 1, collectively referred to as L and R channels)
The audio signal is input to the A / D converter 104, converted into a digital audio signal, and output. After that, in the signal compression unit 105, for example, it is compressed by so-called ATRAC, which is the same signal encoding method as the so-called mini disc, and stored in the audio buffer memory 106.

For uncompressed audio signals,
Data is directly sent from the A / D converter 104 to the audio buffer memory 106.

Data such as subtitles generated by the character generator 321 is compressed by the compression circuit 401 and sent to the multiplexer 107.

The compressed image, audio and subtitle data sent to the multiplexer 107 are multiplexed. The multiplexed data is then divided into sectors by the sectorize circuit 108, and an error correction code is added by an error correction code addition circuit (ECC circuit) 109. Next, modulation is performed in the modulation circuit 110. The above process is premastering.

In a cutting step 150 for producing a disk master, an EOM (electro-optical modulator) 151 using the so-called Pockels effect is used as a device for optical modulation, and a cutting device 152 performs a cutting process. In the mastering step 160, mastering is performed in the developing process and the vapor deposition process to complete the master of the master. Multiple masters are made from this master, and multiple stampers are made from this mother. In the replication process, the stamper is used to perform injection molding with the injection device 171 and package the optical disc 11.
0 is completed.

Next, the schematic structure of the data reproducing apparatus according to the embodiment of the present invention will be described with reference to FIG.

The optical pickup 112 is the optical disc 1
11 is irradiated with laser light, and the optical disk 1 is obtained from the reflected light.
The data recorded in 11 is reproduced. The disk drive circuit 125 controls the position of the pickup and the rotation speed of the disk in accordance with commands from the ring buffer 117 and the system controller 130. The RF signal reproduced by the optical pickup 112 is equalized by the equalizer 113, and then the clock component included in the RF signal is reproduced by the PLL circuit 114, and the synchronization signal is supplied to the demodulation circuit 115 and the ring buffer 117. To be done. The signal input from the demodulation circuit 115 is supplied to the ring buffer 11 based on the clock of the PLL circuit.
It is taken in by 7 and stored. The data taken into the ring buffer 117 is stored in the error correction circuit (ECC circuit) 1
The error is corrected by 16.

Next, the data is input from the ring buffer 117 to the demultiplexer 118, where it is decomposed into image, audio and caption data and supplied to each decoder.

Of the information decomposed in the demultiplexer 118, the video signal is the code buffer memory 11
9 is stored. The signal output from the code buffer memory 119 is subjected to motion compensation, inverse DCT and the like in the video signal decompression unit 120, and then the post processor 1
After passing through 26, it is converted into an analog signal and output by the D / A converter 121.

Of the information decomposed by the demultiplexer 118, the audio signal is stored in the audio buffer memory 122. The signal output from the audio buffer memory 122 is a so-called ATRA.
Since the signal is compressed by the method C, it is expanded in the audio signal expansion unit 123, converted into an analog signal by the D / A converter 124, and output.

In the case of uncompressed audio data,
Data is directly sent from the audio buffer memory 122 to the D / A converter 124.

Of the information decomposed by the demultiplexer 118, subtitle signals and the like are included in the subtitle decoder 400.
And is stored in the subtitle code buffer memory 333. The signal output from the subtitle code buffer memory 333 is decompressed and restored by the subtitle decoder 400, and then sent to the post processor 126, superposed on a video image and sent to the D / A converter 121.

The user interface 131 receives a command such as "play" or "stop" from the user and instructs the system controller 130. The system controller 130
According to the instruction, the disk drive 125, the demultiplexer 118, and each decoder are controlled to realize the operation desired by the user.

Next, a concrete example of the moving picture compression system in the embodiment of the present invention will be shown. When a moving image is digitized and recorded and reproduced, the amount of data becomes enormous, so that data compression is performed. As a method for compressing moving image information, a predetermined number of pixels are divided into blocks, and motion prediction coding and discrete cosine transform coding are adaptively performed in frame units, field units, slice units or block units according to the information amount of the original image. To use. In this case, the aspect ratio (aspect ratio)
A 4: 3 original image or a 16: 9 original image horizontally reduced to 4: 3 squeeze image 1 frame of image is 2
Compress to M bits or less. In addition, variable length coding that allocates more recording bits to an image frame having a large amount of information is used.

The same blocks in FIG. 3 as those in FIG. 1 are designated by the same reference numerals. A portion surrounded by a broken line in FIG. 3 is the video signal compression unit 102 in FIG.
In FIG. 3, the constituent elements shown as each block in the figure are functionally expressed, and by using a CPU and a memory or the like, the same circuit is used by area division or time division use. Of course, it is possible to have a plurality of functions.

As described above, the input luminance signal Y and the color difference signals RY and BY are A / D converted by the A / D converter 101 and stored in the frame memory 1.
(For convenience, it is represented by a single signal line.) The data stored in the frame memory 1 is read therefrom and input to the DCT circuit 3 via the subtractor 2.

The DCT circuit 3 converts the input data to DC.
Perform T (discrete cosine transform) processing. The data output from the DCT circuit 3 is input to the quantization circuit 4 and quantized, and then input to the variable length coding circuit (VLC circuit) 5, converted into a variable length code such as Huffman code, and converted into a video code. It is supplied to the buffer 103 and stored.

The data quantized by the quantization circuit 4 is inversely quantized by the inverse quantization circuit 7. The data inversely quantized by the inverse quantization circuit 7 is further input to the inverse DCT circuit 8 and subjected to inverse DCT processing. Inverse DCT circuit 8
The data output by is supplied to and stored in the frame memory 10 via the adder 9.

On the other hand, the motion detection circuit 11 detects the motion of the image stored in the frame memory 1 and outputs the motion vector to the VLC circuit 5 and the motion compensation circuit 12. The motion compensation circuit 12 performs motion compensation on the data stored in the frame memory 1 corresponding to the motion vector, and outputs the data to the subtractor 2 and the adder 9. The subtractor 2 subtracts the data input from the motion compensation circuit 12 from the image data input from the frame memory 1. As a result, a P picture is generated as a predicted image (an image serving as a reference for taking a difference) that has been previously decoded in time and is used as a predicted image. Predict three types of images: an interpolated image made from a previously-decoded I-picture or P-picture, a temporally-deposited already-decoded I-picture or P-picture, or both A B picture (bidirectional predictive coded image) as an image is generated. The I picture is generated when the data from the motion compensation circuit 12 is not used and only the data supplied from the frame memory 1 is supplied to the DCT circuit 3.

The adder 9 adds the data input from the motion compensation circuit 12 and motion-compensated to the data supplied from the inverse DCT circuit 8 to generate a P-picture or B-picture decoded image. , And supplies it to the frame memory 10 for storage. That is, the image data obtained by decoding the same data as the data quantized by the quantization circuit 4 and supplied to the video code buffer 103 through the VLC circuit 5 is stored in the frame memory 10 by this.
As a result, using the data stored in the frame memory 10, it becomes possible to obtain P picture data or B picture data.

The high-efficiency coding method of the image signal as described above has the following principle in detail. That is, in this high-efficiency coding method, the redundancy in the time axis direction is first reduced by taking the difference between the images, and then the so-called DCT (discrete cosine transform) processing and the variable length code are used to perform the spatial axis coding. I try to reduce the redundancy of the direction.

First, the redundancy along the time axis will be described below. In general, in a continuous moving image, temporally preceding and succeeding images are very similar to an image of interest (that is, an image at a certain time). For this reason, as shown in FIG. 4, for example, if the difference between the image to be encoded now and the image that is ahead in time is calculated and the difference is transmitted, the redundancy in the time axis direction can be obtained. It is possible to reduce the amount of information to be transmitted by reducing it. The image coded in this way is called a forward predictive coded image (Predictive-coded picture, P picture or P frame) described later. Similarly, the above-mentioned image to be encoded, forward or backward in time, or
It is possible to reduce the amount of information to be transmitted by reducing the redundancy in the time axis direction by taking the difference from the interpolated images made from the front and the back and transmitting the difference of the smaller value among them. Become. The image coded in this way is a bidirectional predictive coded image (Bidirectionally
Predictive-coded picture, B picture or B frame). In FIG. 4, an image indicated by I in the figure is an intra-coded image (Intra-coded picture, I picture or I frame) described later, and an image indicated by P in the figure is the above P A picture is shown, and an image shown by B in the figure shows the B picture.

Further, so-called motion compensation is performed in order to create each predicted image. That is, according to this motion compensation, for example, a block of 16 × 16 pixels (hereinafter referred to as a macroblock) composed of a unit block of 8 × 8 pixels is created, and the block near the position of the macroblock in the previous image is the closest. It is possible to reduce the amount of data that needs to be sent by searching for a portion having a small difference and taking the difference with the searched macroblock. Actually, for example, in the P picture (forward predictive coded image), the data of the difference between the predicted image after motion compensation and the difference between the predicted image after motion compensation and the predicted image after motion compensation is not calculated. Those having a small amount are selected and encoded in units of the macro blocks of 16 × 16 pixels.

However, in the above-mentioned case, a lot of data must be sent, for example, for the part (image) coming out from the back of the moving object. Therefore, for example, in the B picture (bidirectional predictive coded image), the already decoded temporally forward or backward image after motion compensation, and an interpolated image created by adding both of them will be encoded from now on. The difference between the image and the image to be encoded and the one that does not take the difference, that is, the one with the smallest data amount out of the four images to be encoded from now on are encoded.

Next, the redundancy in the spatial axis direction will be described below. The difference of the image data is not transmitted as it is, but DCT is performed for each unit block of 8 × 8 pixels.
Apply (discrete cosine transform). The DCT represents an image not by the pixel level but by which frequency component of the cosine function is included and by how much, for example, 2
By the dimension DCT, the data of the unit block of 8 × 8 pixels is converted into the coefficient block of the component of the 8 × 8 cosine function. For example, an image signal of a natural image taken by a television camera is often a smooth signal. In this case, the data amount can be efficiently reduced by performing the DCT process on the image signal.

That is, for example, in the case of a smooth signal such as the image signal of the above-mentioned natural image, by applying the DCT, large values are concentrated around a certain coefficient. When this coefficient is quantized, most of the 8 × 8 coefficient block becomes 0, and only large coefficients remain. Therefore, when transmitting the data of the 8 × 8 coefficient block, a set of so-called zigzag scans and non-zero coefficients and so-called 0 runs indicating how many 0s precede the coefficient are set. By transmitting the variable length code such as the so-called Huffman code, the transmission amount can be reduced. On the decoder side, the image is reconstructed in the reverse procedure.

FIG. 5 shows the structure of data handled by the above-mentioned coding system. That is, the data structure shown in FIG. 5 is composed of a block layer, a macroblock layer, a slice layer, a picture layer, a group of picture (GOP) layer, and a video sequence layer in order from the bottom. Become. Hereinafter, in FIG. 5, the layers will be described in order from the bottom.

First, in the block layer, the block of the block layer is composed of 8 × 8 pixels (8 lines × 8 pixels) adjacent to each other in luminance or color difference. The DCT (discrete cosine transform) described above is applied to each unit block. In the macroblock layer, the macroblocks of the macroblock layer include four luminance blocks (luminance unit blocks) Y that are adjacent to each other in the left, right, top, and bottom directions.
0, Y1, Y2, Y3 and color difference blocks (color difference unit blocks) Cr, Cb corresponding to the same position as the luminance block on the image are composed of a total of six blocks. The order of transmission of these blocks is Y0, Y1, Y2,
The order is Y3, Cr, Cb. Here, in the encoding method, what is used for a prediction image (reference image for obtaining a difference), or it is not necessary to send the difference is determined in units of this macroblock.

The slice layer is composed of one or a plurality of macroblocks which are continuous in the scanning order of the image. At the beginning of this slice (header), the difference between the motion vector and the DC (direct current) component in the image is reset, and the first macroblock has data indicating its position in the image, and thus the error is It is designed to be able to return even if it happens. Therefore, the length and starting position of the slice are arbitrary and can be changed depending on the error state of the transmission path.

In the picture layer, each picture, that is, each image is composed of at least one or a plurality of slices. Then, each of the intra-coded images (I
Picture or I frame), the forward predictive coded image (P picture or P frame), bidirectional predictive coded image (B picture or B frame), and DC intra coded image (DC coded (D) picture). Classified into images.

Here, in the above intra-coded image (I picture), only information closed in one image is used at the time of encoding. Therefore, in other words, the image can be reconstructed only with the information of the I picture itself when decoding. Actually, the DCT processing is performed as it is and the encoding is performed without taking the difference. This coding method is generally inefficient, but if it is put everywhere, it is possible to perform independent decoding without decoding the preceding and subsequent images, so that random access and high-speed reproduction are possible.

In the forward predictive-coded image (P picture), an I picture or P picture that is located earlier in time and is already decoded at the input is used as a predictive image (image serving as a reference for taking a difference). To do. Actually, whichever is more efficient is selected for encoding the difference from the motion-compensated predicted image or for encoding as it is without taking the difference (intra-code).

Bidirectional predictive coded image (B picture)
In the above, three types of I-pictures or P-pictures, which are temporally positioned in advance and already decoded, and interpolated pictures made from both of them, are used as prediction pictures. This allows
It is possible to select the most efficient one of the above three types of differential encoding after motion compensation and the intra code in macroblock units.

The DC intra-coded image is an intra-coded image composed only of DC coefficients of DCT,
It cannot exist in the same sequence as the other three types of images.

The group of pictures (GOP) layer includes one or a plurality of I pictures and 0 or a plurality of non-I pictures.
And a picture. Here, the input order to the encoder is, for example, 1I, 2B, 3B, 4P * 5B, 6
B, 7I, 8B, 9B, 10I, 11B, 12B, 13
P, 14B, 15B, 16P * 17B, 18B, 19
When I, 20B, 21B and 22P are used, the output of the encoder, that is, the input of the decoder is, for example, 1I, 4
P, 2B, 3B * 7I, 5B, 6B, 10I, 8B, 9
B, 13P, 11B, 12B, 16P, 14B, 15B
* 19I, 17B, 18B, 22P, 20B, 21B. In this way, the order is changed in the encoder, for example, when the B picture is encoded or decoded, the I picture or P that is the temporally backward prediction image is the predicted image. This is because the picture must be encoded first. Here, the interval of the I picture (for example, 9) and the interval of the I picture or the B picture (for example, 3) are free. Also, I picture or P
The picture interval may change within the group of pictures layer. The break in the group of pictures layer is represented by *. Further, the I is an I picture, the P is a P picture, and the B is a B picture.

The video sequence layer includes the image size,
It is composed of one or a plurality of group of picture layers having the same image rate and the like. As described above, in the case of transmitting a moving image standardized by the high-efficiency encoding method based on MPEG, first, an image obtained by compressing one image within a picture is sent, and then this image is motion-compensated. The difference from the image is transmitted.

On the other hand, the rate controller 6 monitors the storage amount of data in the video code buffer 103, and adjusts the quantization step size in the quantization circuit 4 so that the storage amount does not overflow or underflow. As a result, the bit rate Rv supplied from the VLC circuit 5 to the video code buffer 103 changes, and the overflow or underflow of the video code buffer 103 is prevented. Then, the data thus stored in the video code buffer 103 is sent to the multiplexer 107.

Next, an embodiment of the voice compression system in the embodiment of the present invention will be described. Similar to the compression of a moving image, when a sound is digitized and recorded and reproduced, the data amount becomes enormous, so the data is compressed.

A plurality of compression-encoded or non-compression-encoded audio signals are recorded together with moving image information. As a method of compressing and encoding the audio signal, the digital audio data is divided into predetermined time units and divided into blocks, and each block is orthogonally transformed into spectrum data on the frequency axis, and the number of allocated bits is determined. A compression coding method is used in which bits are assigned to each spectrum according to characteristics.

In FIG. 6, each block surrounded by a broken line is shown in FIG.
Corresponds to the block with the same number shown in. In FIG. 6, the constituent elements shown as blocks in the figure are functionally expressed, and the same circuit is used by area division or time division by using a CPU and a memory. Of course, it is possible to have a plurality of functions.

In the block diagram shown in FIG. 6, multi-channel audio (4 channels in the block diagram)
The signals are converted into digital signals in A / D converters 201 to 204, respectively. After that, the audio data of each channel is converted into so-called ATR as described later.
In the AC encoders 205 and 206, the ATRAC
Memory controller 207 after being compressed according to the method
Is written into the audio buffer memory 208 at. When a predetermined amount of the audio data is stored in the audio buffer memory 208, the audio data compressed for each channel by the memory controller 207 is read out from the audio buffer memory 208 in a predetermined order and data latched. 209 and then to the multiplexer 107.

In the case of an uncompressed audio signal, A
Data is directly sent from the / D converters 201 to 204 to the audio buffer memory 208.

Here, a method of compressing one channel of the audio data by the so-called ATRAC method will be described. As shown in FIG. 7, the audio data input to the input terminal 31 is separated by the analysis filter 32 into a high frequency component and a middle low frequency component, and the middle low frequency component is further divided into a middle frequency component by the analysis filter 33. It is separated into low frequency components. The high frequency component from the analysis filter 32 is sent to an MDCT (improved discrete cosine transform) circuit 35H via a delay circuit 34. The middle band component and the low band component from the analysis filter 33 are
It is sent to the MDCT circuits 35M and 35L, respectively. The signal of each component from the analysis filters 33 and 34 is sent to the block size determination circuit 36, the block size determination signal at the time of the above-mentioned improved discrete cosine transform is taken out, and each improved discrete cosine transform (MDCT) circuit 35H, 35
It is sent to M and 35L respectively. Each MDCT circuit 35
The data signals on the frequency axis output from H, 35M, and 35L are respectively taken out through output terminals 37H, 37M, and 37L. Data compression is performed on the output signals on these frequency axes by thinning out the data based on the human auditory characteristics (in particular, the minimum audible limit characteristic and the auditory masking effect).

As the subtitle data, as shown in FIG. 8, the character signal generated by the character generator 321 is converted into the subtitle encoding device 40.
Input to 1. In the subtitle encoding device 401, the input character data is quantized by the quantizer 322, and the run-length encoder 323 at the next stage encodes the level value and the run.
After that, the run is variable-length coded by the variable-length encoder 324. In the packing unit 325 at the final stage, the 4-bit luminance level value and the variable-length coded run are packed to be the same as the time code of the video frame for displaying the timing for displaying the subtitle, and the time code Register the value. At the same time, the subtitle display position in the video frame to be displayed is registered.

At this time, the generated information amount of the caption data is calculated at fixed time intervals, and the result is calculated as the video signal compression unit 1.
It transmits to the rate controller 6 in 02. As a result, the rate controller 6 knows the information amount of the subtitle data, and therefore, at the time of video encoding, it is possible to perform variable-rate video encoding processing that maximizes the disk capacity.

For services using teletext, teletext, and other blanking areas, input from the character generator 321 to the subtitle encoding device 401 in the same manner,
By the above processing, encoding is performed independently of the video data within the valid period.

Next, the processing after the multiplexer 107 will be described. In FIG. 1, the signal multiplexed by the multiplexer 107 is divided into sectors by the sectorizing circuit 108.

FIG. 9 shows an example of the data format of the recording / reproducing apparatus of the present invention. In FIG. 9, circles indicate 1-byte data. The signal output from the multiplexer 107 is divided into 1 sector every 2 kilobytes including 8 bytes of the sector header. The sector header includes a sector address that is incremented by 1 for each sector.

After the sectorization of all the data is completed in this way, the information of the access point of the video and audio data and the sector address thereof is changed to TOC (Table Of Cont).
ents) is added to the beginning of all data.

The sectorized data is then input to the error correction code adding circuit 109. 128 for each sector
For each byte, a 16-byte RS (Reed Solomon) code is calculated for the data read in the diagonal direction (direction A) and added as an inner parity. In the figure, the circle marked with a vertical line corresponds to the inner parity. The inner parity is so-called convolved, and the parity is calculated without interruption from the beginning to the end of the data.

Next, the data is read in the horizontal direction (B direction) for the row for which the calculation of the inner parity has been completed, and the RS code is 16 bytes and the outer parity is 128 bytes for the data and 16 bytes for the inner parity. Will be added as. In the figure, the horizontal circles represent outer parity. After that, the data for which the parity addition is completed is sent to the next modulation circuit 110 in the order of B direction.

The modulation circuit 110 performs, for example, EFM modulation on the input data. Further, as shown in FIG. 9, a sync signal is added to the beginning of each row in units of 160 bytes.

The signal that has undergone the above processing is sent to a cutting machine, and the master master is cut. The above is the configuration and operation of the encoder part.

Data reproduction in the optical disk device according to the embodiment of the present invention will be described below with reference to FIG. In this optical disc reproducing apparatus, the optical disc 1
The recording data is read at a constant rate of 11 to 30 Mbit / sec or less. Then, this recording data is stored in the ring buffer 42 having a data capacity of at least the outermost circumference of the optical disc 111, and the data is output from the ring buffer 42 in response to a decoding request. At this time, depending on the remaining amount of data in the ring buffer 42, the pickup 112 waits for the adjacent track jump. And
The data read from the ring buffer 42 is separated by the demultiplexer 118 into moving image data, audio data, subtitle data, and the like. In this case, the demultiplexer 11
The video decoder 120 performs motion prediction decoding and discrete cosine inverse transform decoding on each block of the compressed moving image data output from the video decoder 120 to decode and reproduce the moving image.

FIG. 10 is a block diagram showing an example of the structure of data reproduction in the embodiment of the present invention, and the portions corresponding to those in FIG. 2 are assigned the same numbers.
The data recorded on the optical disc 111 is reproduced by the pickup 112. The pickup 112 irradiates the optical disc 111 with laser light and reproduces the data recorded on the optical disc 111 from the reflected light. The reproduction signal output from the pickup 112 is a waveform equalization circuit (equalizer) 113, demodulation circuit 1
It is written in the ring buffer 42 via 15.

Considering the above-mentioned FIG. 9 as representing the memory space of the ring buffer, the data is sequentially written in the B direction. The sync signal portion is extracted by the demodulation circuit 115 and is not written in the ring buffer 42.

The data written in the ring buffer memory 42 is stored in the error correction circuit 11 in the same B direction as at the time of writing.
The data is read out to 6, and the error correction is performed by the outer parity. Then, the correct data only for the erroneous data is output from the error correction circuit 116 to the ring buffer memory 42.
It is sent to 1 and rewritten.

The data that has been corrected by the outer parity in the ring buffer memory 42 is then corrected by the inner parity. That is, the data is read in the direction A of FIG. 9 and output to the ECC circuit 116. If there is an error, the ECC circuit 116 sends the correct value of the data to the ring buffer memory 42 for rewriting.

The data in the ring buffer memory 42 which has been subjected to error correction by the inner / outer parity is output to the demultiplexer 118 in response to the request from the video code buffer memory 119. Here, the data sent to the demultiplexer 118 is moving image audio compressed data excluding the inner / outer parity and the sector header.

On the other hand, the corrected data output from the ECC circuit 116 is sent to the sector detection circuit 41, the sector address in the sector header is read, and the information is sent to the control circuit 43. When the addresses cannot be detected or the detected addresses are not consecutive, for example, a sector number abnormal signal is output to the track jump determination circuit 44.

When the ECC circuit 116 cannot correct the data error, it outputs an error occurrence signal to the track jump determination circuit 44.

The track jump determination circuit 44 monitors the output of the control circuit 43, outputs a track jump signal to the tracking servo circuit 45 when a track jump is required, and causes the reproduction position of the pickup 112 to perform the track jump. . Further, the track jump determination circuit 44 detects the sector number abnormal signal from the sector detection circuit 41 or the error occurrence signal from the ECC circuit 116, outputs the track jump signal to the tracking servo circuit 45, and tracks the reproduction position of the pickup 112. It's designed to jump.

The control circuit 43 uses the ring buffer memory 4
In addition to controlling the writing and reading of 2, the code request signal requesting the data output from the inverse VLC circuit 21 via the video code buffer 119 is monitored.

The control circuit 43 specifies an address (write point (WP)) on the ring buffer 42 in which the data from the demodulation circuit 115 should be written. Further, the control circuit 43 takes in the sector address information sent from the sector detection circuit 41 and manages which sector is written in which address on the ring buffer memory 42. Also, based on the code request signal from the video code buffer 119 in the subsequent stage, the ring buffer memory 4
The read address reproduction point (RP) of the data written in 2 is designated, the data is read from the reproduction point (RP), and is output to the demultiplexer 118.

The data input to the demultiplexer 118 is separated into a moving image signal, an audio signal and a caption signal. This separated moving image compression signal is sent to the video code buffer 119.

The control circuit 43 uses the video code buffer 1
The data stored in the ring buffer memory 42 is supplied to the video code buffer memory 119 in response to the code request signal from the video code buffer signal 19 from the video code buffer memory 119 to the inverse VLC circuit. When the data transfer amount per unit time to 21 decreases, the ring buffer memory 42
The amount of data transferred from the video code buffer memory 119 to the video code buffer memory 119 also decreases. Then, the amount of data stored in the ring buffer memory 42 increases and there is a risk of overflow. Therefore, the track jump determination circuit 44 calculates the amount of data currently stored in the ring buffer memory 42 by the write point (WP) and the reproduction point (RP), and the data amount is set to a predetermined reference value set in advance. When it exceeds the value, it is determined that the ring buffer memory 42 may overflow, and a track jump command is output to the tracking servo circuit 45.

Further, the track jump determination circuit 44 is
When the abnormal sector number signal from the sector detection circuit 41 or the error occurrence signal from the ECC circuit 116 is detected, the amount of data remaining in the ring buffer memory 42 is similarly determined from the write address (WP) and the read address (RP). While seeking, while the optical disk 111 makes one rotation from the current track position (optical disk 1
11 while waiting for one rotation), the ring buffer memory 42
To the video code buffer memory 119, the amount of data required to guarantee the reading is obtained. When the amount of remaining data in the ring buffer memory 42 is large, underflow does not occur in the ring buffer memory 42 even if data is read from the ring buffer memory 42 at the highest transfer rate. It is judged that error recovery is possible by reproducing the generation position again with the pickup 112, and a track jump command is output to the tracking servo circuit 45.

When the track jump determination circuit 44 outputs a track jump command, the tracking servo circuit 45 causes the pickup 1 to move as shown in FIG.
The reproduction position by 12 is jumped from the position A to the position B on the inner circumference of one track. (Data is recorded on the disc from the inner circumference to the outer circumference, and the pickup reads from the outer circumference.) Then, the control circuit 43.
At the reproduction position until the optical disc 111 makes one revolution again and reaches the position A from the position B, that is, until the sector number obtained from the sector detection circuit 41 becomes the sector number at the time of the track jump. Is prohibited from being written to the ring buffer memory 42, and the data already stored in the ring buffer memory 42 is transferred to the video code buffer memory 119 via the demultiplexer 118 as necessary.

After the track jump, even if the sector number obtained from the sector detection circuit 41 matches the sector number at the time of the track jump, the amount of data stored in the ring buffer memory 42 exceeds the predetermined reference value. In this case, that is, when the ring buffer memory 42 may overflow, the ring buffer memory 42
The writing of data to is not restarted, and the track jump is performed again.

As described above, according to the remaining amount of data in the ring buffer memory 42, the position of the pickup 112 is waited by the adjacent track jump.

The data output from the video code buffer memory 119 is the variable length decoding circuit (inverse VLC circuit) 2
1 and the variable length code is decoded.

The inverse quantization circuit 22 inversely quantizes the data supplied from the inverse VLC circuit 21 according to the quantization step size data supplied from the inverse VLC circuit 21. This quantization step size and inverse VLC circuit 21
The motion vector supplied from the motion compensation circuit 25 to the motion compensation circuit 25 is supplied from the rate controller 6 and the motion detection circuit 11 to the VLC circuit 5 in the encoder, and is recorded on the optical disc 111 via the video code buffer memory 103 together with the image data and reproduced. It was done.

The inverse DCT circuit 23 performs inverse DCT processing on the data supplied from the inverse quantization circuit 22. When the inverse DCT-processed data is I-picture data, it is directly supplied to the frame memory 26 via the adder 24 and stored therein. When the data output from the inverse DCT circuit 23 is P picture data in which an I picture is a predicted image, the I picture data is called from the frame memory 26, motion compensated in the motion compensation circuit 25, and then added. 24. This adder 24 has an inverse D
The data output from the CT circuit 23 and the motion compensation circuit 2
The data output from 5 is added to generate P picture data. This data is also stored in the frame memory 26.

When the data output from the inverse DCT circuit 23 is B picture data, I picture or P picture data is read from the frame memory 26, motion compensated by the motion compensation circuit 25, and then added by the adder 24. Is supplied to. The adder 24 adds the data output from the inverse DCT circuit 23 and the data output from the motion compensation circuit 25, so that decoded B picture data is obtained. This data is also stored in the frame memory 26.

The image data stored in the frame memories 26a, 26b, 26c is output to the post processor 126 in the frame order of the original image by switching the switch 26d.

In the post processor 126, as shown in FIG. 12, the input image data is stored in the field memory 3
The filter circuit 31 delays one field by 13
Filter operation is performed in 2, and it is converted into a letterbox. Switching device 3
Output to 14b. The output of the squeeze image expansion circuit 315 that expands the input image data in the horizontal direction from the aspect ratio of 4: 3 to 16: 9 is connected to the switch 314c. The output of the input image data itself is connected to the switch 314a.

The mixing circuit (mixing circuit) 311 selectively inputs these signals by the switch 314 according to the instruction of the system controller 130. Aspect ratio 4:
The switch 314 is connected to the switch 314a in the image No. 3, and the switch 314a and the switch 314b are connected to the squeeze image. The mixing circuit 311 superimposes the output from the caption decoder 400, which will be described later, on the image data and transfers it to the D / A converter 121.

In addition, the mixing circuit 311 inserts signals such as teletext and teletext into the blanking area according to an instruction from the subtitle decoder 400.

The image data is D / A converted by the D / A converter 121 and then output as an analog video signal. The above is the configuration and operation in the decoder section.

Next, decoding of the audio signal will be described. In the optical disk reproducing device, the audio compression information output from the demultiplexer 118 is decompressed and reproduced for each block.

In FIG. 2, the audio buffer 122
Writes the audio data transferred from the demultiplexer 118 to a predetermined address on the audio buffer memory according to the request from the demultiplexer 118. At this time, the audio data to be transmitted is time-divisionally sent in the order in which multi-channel data is defined, so the audio buffer 122 stores predetermined data in the memory area allocated to each channel. Is written.

The audio data thus fetched is processed by the audio decoder according to the signal timing generated by the system control so that the difference between the processing time for decoding the image data and the processing time for decoding the audio data is corrected. Predetermined audio data is transferred to each channel. That is, it has a demultiplexer for multi-audio data and two functions for correcting a difference in processing time between image data and audio data.

Communication between the audio buffer and the demultiplexer uses 9 parallel data lines (8 audio data, 1 error flag data) and 1 transmission line for each of the write signal and the full signal. . FIG. 13 shows a block diagram of the audio decoder side. In the data latch 301, signals on 9 parallel data are latched. Here, the error flag is the ECC circuit 116.
It shows the data that cannot be error-corrected.

When the memory controller 302 receives the write signal, the address counters for the audio buffer memory 303 and the error flag buffer 304 are incremented, and the audio buffer memory 303 is incremented.
The error flag buffer 304 is set to the write mode, and the signals stored in the data latch 301 are written.

Next, the so-called ATRAC decoder 305.
In 306 and 306, when a start signal is received from the system controller, a data request (by a REQ signal) is made to the memory controller 302. When the memory controller 302 receives the REQ signal, it sets the address of the data to be read from the audio buffer memory 303 and the error flag buffer 304 in the read address counter, sets the memory in the read mode, and sets the ATRAC decoders 305 and 30.
The data is transmitted to 6. In the ATRAC decoders 305 and 306, the transmitted data is decompressed according to the ATRAC method, and the D / A converters 306 to 309.
Sent to.

Further, the memory controller 302 refers to the contents of the above memory and refers to the audio buffer memory 30.
Judge whether the data is full in 3. If the audio buffer memory 303 is about to fill up, the full signal is activated to request the demultiplexer 118 to stop the transfer of data thereafter. If the audio buffer memory 303 can be opened, the full signal is made passive to notify the demultiplexer 118 of the data waiting state.

In the case of uncompressed audio, the D / A converters 307 and 30 are loaded from the audio buffer memory 303.
The voice data is directly sent to 8, 309 and 310.

Here, a method for expanding one channel of the audio data by the so-called ATRAC method will be described. As shown in FIG. 14, the input terminals 51H, 5
1M and 51L have the output terminals 37H and 37 shown in FIG.
A data signal on the frequency axis corresponding to the output signals from M and 37L is supplied, and IMDCT (Inverse Improved Discrete Cosine Transform) circuits 52H and 5 for performing the inverse transform of the MDCT.
It is sent to 2M and 52L respectively. IMDCT circuit 72
The output signal from H is sent to the synthesis filter 54. Further, the output signal from the delay circuit 53 and the synthesis filter 54
The output signal from is sent to the synthesis filter 55 and is subjected to synthesis processing, and becomes an audio data signal on the time axis and is taken out from the output terminal 56.

The subtitle data supplied from the demultiplexer 118 is input to the selector 331 as shown in FIG. The system controller 130 receives an instruction from the user interface 131 and notifies the subtitle decoder controller 332 of data such as subtitles and teletext to be selected. The subtitle decoder controller 332 switches the selector 331 in accordance with this signal and sends desired data to the subtitle code buffer 333. The subtitle code stored in the subtitle code buffer 333 is read out in accordance with the decoding of the video / audio data, decoded by the variable length decoder 334 and the run length decoding circuit 335, and dequantized by the dequantizer 336 and post-coded. It is sent to the processor 126.

The demultiplexer 118 manages the start timings of the video signal decompression unit 12, the audio signal decompression unit 123, and the subtitle decoder 400, and maintains a normal synchronization relationship. Further, the system information included in the multiplexed data is transmitted to the system controller 130.

The TOC (Table of Table
Contents) information is added, and this data is taken into the system controller from the ring buffer 117 immediately after starting reading the disc.

The system controller 130 controls the disk drive (driving) section, the demultiplexer, the decoder group and the user interface 131.
When the user gives a command, for example, "play", the system controller 130 understands this from the data from the user interface 131. The system controller 130, which has received a command from the user, determines the operation according to its current state. For example, when a "stop" command is received, the operation is stopped without exception.

When the user specifies access to a certain access point on the optical disk 111 through the user interface 131, the system controller 1
The command 30 receives this command from the user interface 130, checks the sector address of the access point specified by the TOC information, and issues a command to the disk drive 125 to jump to that sector and start reading. The above is the description of the operation of the data reproducing apparatus.

Next, the optical disk recording medium, the optical pickup, and the laser used as the light source, which are applied to the present invention, will be described. The optical disk used in the present invention has a diameter of 13
It is an optical disc of 0 mm or less and has an objective lens numerical aperture of 0.
A pit is read out using an optical pickup having a characteristic of 6 or less and a spatial cutoff frequency of 2067 lines / mm or more.

The parameters of the above optical disc are as follows. That is, the track pitch is 0.7 to 0.9 μ
m, the recording linear density is 0.18 to 0.25 μm / bit, the disc recording area has a radius of 20 mm or more and less than 65 mm from the center, the linear velocity is 3.3 to 5.3 m / sec, and the pit shape is an embossed pit. The thickness is 1.2 ± 0.1 mm.

The above-mentioned optical pickup is characterized by having a numerical aperture of the objective lens of 0.6 or less and a spatial cutoff frequency of 267 lines / mm or more, and various short wavelength lasers may be used as the light source. What is currently available is a green laser that oscillates at a wavelength of 532 nm, and has the characteristics of emission light power of 0.5 mW or more, diffraction limit, and low noise. The green laser has a structure described below.

As shown in FIG. 16, the green laser is
A semiconductor laser 61 as a solid-state laser pumping light source, a resonator 62 for stably oscillating the solid-state laser and wavelength conversion inside the solid-state laser, and a coupling such as a lens for optically coupling these two elements as necessary. It has an element 63. Further, it may have a temperature detection element 64 for stabilizing the temperature, an electronic cooling / heating element 65, a photodiode (PD) 66 for stabilizing the emission power, and the like.

The laser cavity 62 is composed of the solid-state laser crystal 6
7. A wavelength conversion element 68 and high-reflection mirrors for the solid-state laser oscillation wavelength are provided at both ends thereof. In addition, the stabilizing element 6
There may be a quarter wave plate or the like as 9. The high-reflecting mirror is provided directly on these elements or is mounted on another substrate.

As the solid-state laser crystal 67, Nd: YA
G, Nd: YVO ₄ , NYAB, etc. are considered. Nd:
In the case of YAG, since the absorption coefficient of pumping light is small, a coupling element 63 such as a lens is provided between the LD chip and the laser resonator 62.
Need to go through. In addition, temperature control is essential because the absorption wavelength is narrow.

On the other hand, since Nd: YVO ₄ has a high absorption coefficient, lateral mode control is possible if it is close to the LD chip even without a lens, and even a thin one can withstand practical use. However, it is difficult to obtain high quality crystals,
There is a defect that the light is distorted as the excitation power increases. In addition, NYAB has the disadvantage that it is difficult to obtain a good quality crystal and the advantage that wavelength conversion is performed at the same time.

As the wavelength conversion element 68, KTiO is currently used.
PO ₄ (KTP) is typical. It has a large incident light wavelength, incident angle, and temperature tolerance for efficiently emitting the second harmonic, is physically and chemically stable, and is not easily damaged by light. In addition to this, MgO: LiNbO ₃ or the like can be used, but the temperature must be maintained at 100 ° C. or higher, which is not suitable for miniaturization.

Although the stabilizing element 69 may not be necessary in some cases,
As an example, the SHG in the resonator can be stabilized by using a quarter wave plate. In addition, an etalon, a polarization selection element, etc. may be used.

The components of the laser resonator 62 described above are non-reflective coated on one side or both sides at the solid-state laser oscillation wavelength, and the both ends of the resonator are confined by the high-reflection coating by the multilayer coating. There is. The solid-state laser light becomes a high-intensity laser as it reciprocates in the laser resonator 62 many times due to these high-reflection coatings, and the wavelength conversion element 68 efficiently shortens the wavelength.

The semiconductor laser 61 as the excitation light source has a high output, and its wavelength is the absorption line (790 to 8) of the solid laser medium.
The solid-state laser can be efficiently oscillated when the peak value is around 15 nm). Since the center wavelength of the semiconductor laser changes at about 0.3 nm / ° C, N
Temperature control is required when d: YAG is excited.

As the temperature detecting element 64, a thermistor,
Platinum resistors and thermocouples are possible. These devices are highly practical because a thermistor having a small size and a high resolution has been used for temperature control of the semiconductor laser 61.

[0122]

EFFECTS OF THE INVENTION Using a green laser having a wavelength of 522 to 542 nm, a moving image is compressed to an optical disc of a CD size of about 12 cm so that one frame image is 2 Mbit or less, and a plurality of audio signals are recorded. The compression encoding enables the optical disc to be stored at a recording density six times higher than that of the conventional CD, so that it is possible to reproduce a digital image and digital audio for 60 minutes or more from the optical disc. That is, it is possible to record a moving image signal and an audio signal having an image quality equivalent to that of a commercial broadcast as digital signals, and record them on a small-diameter optical disc having excellent operability for a long time without deteriorating the image quality and the sound.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a recording side (disc manufacturing side) of an embodiment according to the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a reproducing side according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an embodiment of a video data compression circuit of the optical disc device of the present invention.

FIG. 4 is a diagram for explaining each predicted image.

FIG. 5 is a diagram showing a data structure.

FIG. 6 is a block diagram showing a configuration of an audio buffer and an encoder unit of the optical disc device of the present invention.

FIG. 7 is a block diagram showing a main configuration of an encoder that compresses audio data according to the ATRAC method.

FIG. 8 is a block diagram showing a configuration of an embodiment of a caption data encoding unit of the optical disc device of the present invention.

FIG. 9 is a diagram showing a format configuration of sectors and error correction codes of the optical disc according to the present invention.

FIG. 10 is a block diagram showing a configuration of an embodiment of video data reproduction of the optical disc device according to the present invention.

FIG. 11 is a diagram showing how a track jump is performed in this embodiment.

FIG. 12 is a block diagram showing the configuration of an embodiment of subtitle data reproduction of the optical disc device of the present invention.

FIG. 13 is a block diagram showing a configuration of an audio buffer and a decoder unit of the optical disc device of the present invention.

FIG. 14 is a block diagram showing a main configuration of a decoder for decompressing audio data compressed by the ATRAC method.

FIG. 15 is a block diagram showing the configuration of an embodiment of a subtitle decoder of the optical disc device of the present invention.

FIG. 16 is a block diagram showing a schematic configuration of a green laser oscillator.

[Explanation of symbols]

1 ... Frame memory 2 ... Subtractor 3 ... Discrete cosine converter 4 ... Quantizer 5 ... Variable length encoder 6 ... Rate controller 7 ... Inverse quantizer 8 ... Inverse Discrete Cosine Transformer 9 ... Adder 10 ... Frame Memory 11 ... Motion Detection Circuit 12 ... Motion Compensation Circuit 21 ... Variable Length Decoding Circuit 22 ... Inverse Quantization Circuit 23 ... Inverse discrete cosine transform circuit 24 ... Adder 25 ... Motion compensation circuit 26a, 26b, 26c ... Frame memory 26d ... Switcher 31 ... Input terminal 32, 33 ... Analysis filter 34 ... Delay circuit 35H, 35M, 35L ... Improved discrete cosine transform circuit 36 ... Block size determination circuit 37H, 37M, 37L ... Output terminal 41 ... Sector detection circuit 42 ...・Buffer memory 43 ... control circuit 44 ... track jump determination circuit 45 ... tracking servo circuit 51H, 51M, 51L ... input terminal 52H, 52M, 52L ... inverse improved discrete cosine transform circuit 53. ..Delay circuits 54, 55 ... Synthesis filter 56 ... Output terminal 61 ... Semiconductor laser 62 ... Laser resonator 63 ... Coupling element 64 ... Temperature detection element 65 ... Electronic cooling Element 66 ... Photodiode 67 ... Solid-state laser crystal 68 ... Wavelength conversion element 69 ... Stabilization element 101, 104 ... A / D converter 102 ... Video signal compression unit 103 ... Video code buffer memory 105 ... Audio signal compression unit 106 ... Audio buffer memory 107 ... Multiplex 108 ... Sectorize circuit 109 ... ECC circuit 110 ... Modulation circuit 111 ... Optical disk 112 ... Pickup 113 ... Equalizer 114 ... PLL circuit 115 ... Demodulation circuit 116 ... ECC Circuit 117 ... Ring buffer 118 ... Demultiplexer 119 ... Code buffer memory 120 ... Video signal expansion unit 121, 124 ... D / A converter 122 ... Audio buffer memory 123 ... Audio Signal extension unit 125 ... Disk drive 126 ... Post processor 130 ... System controller 131 ... User interface 151 ... Electro-optical modulator 152 ... Cutting device 161 ... Development processing unit 162. ..Vacuum processing means 17・ ・ ・ Injection device 201, 202, 203, 204 ・ ・ ・ A / D converter 205, 206 ・ ・ ・ ATRAC encoder 207 ・ ・ ・ Memory controller 208 ・ ・ ・ Audio buffer memory 209 ・ ・ ・ Data latch 301 ・ ・ ・Data latch 302 ... Memory controller 303 ... Audio buffer memory 304 ... Error flag buffer 305, 306 ... ATRAC decoder 307, 308, 309, 310 ... D / A converter 311 ... Mixing circuit 312 ... Filter circuit 313 ... Field memory 314 ... Switching device 315 ... Squeeze image expansion circuit 321 ... Character generator 322 ... Quantizer 323 ... Run length encoder 324 ... Variable length encoder 325 ..Packing circuit 331 ... Selector 332 ... Subtitle decoder controller 333 ... Subtitle code buffer memory 334 ... Variable length decoder 335 ... Run length decoder 336 ... Inverse quantizer 400 ... ..Subtitle decoder 401 ... Subtitle encoding device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Miyamori 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (22)

[Claims] 1. An optical disk recording medium in which moving image information is recorded on one side, wherein the track pitch is 0.7 to 0.9 μm, the recording linear density is 0.18 to 0.25 μm / bit, and the disk diameter is 130 mm or less. Recording area: Radius 20mm to 65mm from the center
Less than Linear velocity: 3.3 to 5.3 m / sec Pit shape: Embossed pit Substrate thickness: 1.2 ± 0.1 mm An optical disk recording medium characterized by satisfying each condition. 2. The optical recording medium according to claim 1, wherein 16 or more Reed-Solomon codes per code length are added to the data recorded on the optical disk for error code correction. 3. A modulation system of the optical disc is (4,
22) Run length limited code or (4, 1
9) The optical recording medium according to claim 1, wherein a run length limited code is used. 4. A method of compressing the moving image information, wherein a predetermined number of pixels are divided into blocks, and motion prediction coding and discrete cosine transform coding are used for each block. 3. The optical disc recording medium described in 3. 5. As the compression method of the moving picture information, motion prediction coding and discrete cosine transform coding are adaptively used in frame units, field units, slice units or block units according to the amount of information of the original image. The optical disk recording medium according to claim 1, 2, 3, or 4. 6. A method of compressing the moving picture information, wherein variable length coding for allocating more recording bits to an image frame having a large amount of information is used. Alternatively, the optical disc recording medium according to item 5. 7. The moving image information according to claim 4,
Or, the image information of one frame is 2 Mb by the compression method of 6.
The optical disk recording medium according to claim 1, wherein the optical disk recording medium is compressed and recorded at or below it. 8. As the moving image information, an original image having an aspect ratio of 4: 3 or a so-called squeeze image obtained by horizontally reducing an original image having an aspect ratio of 16: 9 to 4: 3 is compressed to 2 Mbit or less and recorded. The optical disk recording medium according to claim 7, characterized in that: 9. A plurality of compression coded or non-compression coded audio signals are recorded together with the moving image information.
Or the optical disc recording medium described in 8. 10. A compression encoding method of the audio signal, wherein digital audio data is divided into blocks by a predetermined time unit, and each block is orthogonally transformed into spectrum data on a frequency axis and the number of allocated bits is increased. 10. The optical disk recording medium according to claim 9, wherein a compression coding method is used, in which bits are assigned and assigned to each spectrum according to human auditory characteristics. 11. A plurality of compression coded or non-compressed coded superimposing caption data for superimposing are recorded together with the moving image information.
2, 3, 4, 5, 6, 7 or 8 optical disk recording medium. 12. A plurality of information including a teletext to be multiplexed with V blanking of an image signal together with the moving image information is coded and recorded.
The optical disk recording medium according to 3, 4, 5, 6, 7 or 8. 13. An optical disc recording method for recording information such as a moving image on an optical disc recording medium, comprising: track pitch: 0.7 to 0.9 μm recording linear density: 0.18 to 0.25 μm / bit disc diameter: 130 mm or less Disc recording area: Radius 20mm to 65mm from center
Less than linear velocity: 3.3 to 5.3 m / sec Pit shape: embossed pit Substrate thickness: 1.2 ± 0.1 mm In order to create an optical disk recording medium satisfying each condition, the above moving image information is recorded. An optical disk recording method characterized by the above. 14. An optical disc reproducing apparatus for reproducing information such as a moving image recorded on an optical disc recording medium, wherein: track pitch: 0.7 to 0.9 μm recording linear density: 0.18 to 0.25 μm / bit disc diameter : 130mm or less Disk recording area: Radius 20mm to 65mm from center
Less than linear velocity: 3.3 to 5.3 m / sec Pit shape: embossed pit Substrate thickness: 1.2 ± 0.1 mm An optical disk recording medium satisfying each condition is used, and the numerical aperture of an objective lens is 0.6 or less Space An optical disk reproducing apparatus using an optical pickup having a cutoff frequency of 2067 lines / mm or more. 15. An optical disk reproducing apparatus for reproducing information such as the moving image, wherein the optical disk recording medium is 30.
15. The optical disk reproducing device according to claim 14, wherein the recording data is read at a constant rate of Mbit / sec or less. 16. An optical disk reproducing apparatus for reproducing information such as the moving image, the data read from the optical disk recording medium at a constant rate is stored in a ring buffer having a data capacity of at least the outermost circumference of the optical disk for decoding. The data is output from the ring buffer in response to a request.
4. The optical disk reproducing device described in 4 or 15. 17. An optical disk reproducing apparatus for reproducing information such as the moving image, wherein the optical pickup position is waited by an adjacent track jump according to the remaining amount of data in the ring buffer. 15. The optical disk reproducing device described in 15 or 16. 18. An optical disc reproducing apparatus for reproducing information such as the moving image, wherein the data read from the ring buffer is separated into moving image data, audio data, caption data and the like by a demultiplexer. The optical disk reproducing device according to claim 14, 15, 16 or 17. 19. An optical disc reproducing apparatus for reproducing information such as the moving image, wherein compressed video image data output from the demultiplexer is motion-predicted and discrete cosine inverse transform decoded for each block by a video decoder. 19. The optical disk reproducing apparatus according to claim 14, 15, 16, 17 or 18, wherein the moving image is decoded and reproduced. 20. An optical disk reproducing apparatus for reproducing information such as the moving image, wherein the moving image signal decoded and reproduced by the video decoder is converted into an image having an aspect ratio of 16: 9 when necessary. Claims 14, 15, 16, 17, 1
8. The optical disk reproducing device described in 8 or 19. 21. An optical disk reproducing apparatus for reproducing information such as the moving image, wherein the audio compression code output from the demultiplexer is expanded, decoded and reproduced for each block. 17. The optical disk reproducing device described in 17 or 18. 22. In an optical disc reproducing apparatus for reproducing information such as the moving image, the subtitle data and V blanking information output from the demultiplexer are decoded, and superimposed on the decoded moving image signal. The optical disk reproducing device according to claim 14, 15, 16, 17 or 18, wherein the optical disks are mixed.