JPH11134845A - Optical disk reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize the actual reproducing time of each music program on the occasion of reproducing the introducing part with a disk recording/ reproducing apparatus for reproducing an optical disk on which a plurality of music data in different compression ratios are recorded. SOLUTION: Music data from a magneto-optical disk is stored in a memory and it is then read through expansion and the compression ratio information, for example, from TOC of magneto-optical disk is read. The reproducing time from the magneto-optical disk of each music data is calculated depending on this compression ratio information. When the reproducing time of data from this reproducing time has exceeded the predetermined time, the control is performed so that the pickup is moved to the leading position of the next music program to reproduce the next music program and the music data is accumulated to the memory for the predetermined time from the leading position of each music. Thereby, the scanning of the introducing portion can be realized in such a manner that the actual reproducing time of each music program can be equalized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data reproducing apparatus for reproducing an optical disk on which music information is recorded, and more particularly to an optical disk reproducing apparatus having an introscan function.

[0002]

2. Description of the Related Art Conventionally, a so-called CD (compact disk) in which music information is recorded on an optical disk has been generally used.
2. Description of the Related Art There is known an optical disc reproducing apparatus having a so-called intro scan function for sequentially reproducing only a head portion of each recorded tune for several seconds.

This intro scan is disclosed in, for example,
As described in Japanese Patent Application Laid-Open No. 4-7511, the TOC (Table of Record) recorded on the innermost circumference of the disk is not described.
Based on the content) information, the pickup is moved to the head position of the song, the recorded music information is reproduced for a preset time (several seconds), and then the pickup is moved to the head position of the next song. The operation of reproducing the recorded music information for the preset time is performed for each music piece.

By the way, the applicant of the present application has previously described a technology for reproducing a disk in which data-compressed music information is continuously recorded on a track of the disk, for example, in Japanese Patent Application No. 2-169977. This is proposed in the specifications and drawings of Japanese Patent Application Nos. 2-282121 to 2-2823.

In this technique, a magneto-optical disk or the like is used as a recording medium, for example, a so-called CD-I (CD-Intera).
ACT), AD (adaptive difference) PCM audio data defined in the audio format of CD-ROM XA, or digital audio data bit-compressed and encoded in accordance with another format. In the bit-compressed digital audio data, a connection sector (ringing sector) is added before and after every 32 sectors, for example, in consideration of the interleave between adjacent sector data, using a predetermined data amount as a recording unit. In addition, recording is performed in bursts (intermittently) in consecutive sectors.

Here, for example, so-called standard CD (compact disk) format data (CD-DA) or so-called straight PCM audio data obtained by simply linearly quantizing an analog audio signal is approximately 1 / Consider the case of recording and reproducing with bit compression to 4. The playback time (play time) of the disc recorded with the bit compression of approximately 1/4 is approximately four times that of recording the straight PCM data before compression, for example, the data of the CD-DA format. Become. This means that a smaller disk can provide the same recording / reproducing time as a standard 12 cm CD, so that the apparatus can be downsized. In addition, by setting the (instantaneous) bit rate of recording and reproduction to be the same as that of the standard CD-DA format, the time required for actually writing to and reading from the disk is substantially reduced. Since only 1/4 is required, the remaining approximately 3/4 time can be allocated to a so-called retry or the like. Specifically, for example, at the time of data recording, a confirmation (verify) operation of whether or not recording was performed normally, and a rewriting operation at the time of not being able to perform normal recording, etc. This is a re-read operation when the error rate of reproduced data is high. Thus, recording and reproduction can be performed more reliably even under a bad condition in which the mechanical unit vibrates due to a disturbance and focus, tracking, and the like are deviated, and application to a small portable device becomes possible.

[0007] In order to record and reproduce such digital audio data that has been bit-compressed by approximately 1/4,
A buffer memory for recording and / or reproducing compressed data is required. In this memory, during recording, compressed data is continuously written at a constant rate, and is read out in bursts or intermittently at approximately four times the speed. One data amount at the time of this burst reading is a predetermined data amount serving as the recording unit, for example, 32 sectors. As described above, several sectors for front and rear ringing are added, and a spatial (Continued to the previous recording portion). At the time of reproduction, data of the data amount of the predetermined recording unit (for example, 32 sectors + several sectors for ringing) is reproduced from the disk in a burst or intermittent manner at a speed approximately four times as high as the above. The ringing sector is removed and written to the buffer memory.
The compressed data is continuously read from the memory at the constant rate.

The compression rate of the recording data is not limited to one type, but several types are prepared in advance.
It is conceivable to switch the compression ratio in accordance with the content and use of data. In this case, a plurality of data files (for example, music pieces) having different compression rates may be recorded on one recording medium, for example, one disk.

[0009]

However, when the above-described intro scan is performed using a disk on which a plurality of music pieces having different compression ratios are recorded, the time required for reading each music piece from the disk is fixed. In this case, there is a disadvantage that the playback time of the expanded music data differs from music to music. That is, for example, the first song has a compression of 1/4 (compression ratio 4), the second song has a compression of 1/2 (compression ratio 2),
If the third song is recorded at 1/8 compression (compression rate 8), and the beginning of each song is read from the disk for 2 seconds, the playback time of the expanded playback signal of each song is
The first song is 8 seconds, the second song is 4 seconds, the third song is 16 seconds,
The second song is too short and the third is too long.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an optical disk reproducing apparatus having an intro scan function in which the reproduction time between songs is almost always constant. To provide.

[0011]

An optical disk reproducing apparatus according to the present invention is an optical disk reproducing apparatus which reproduces an optical disk on which compressed music data is recorded and in which start position information of each music is recorded. Playback position control means for controlling the movement of the pickup to the head position of each song based on the head position information of the song, and music data compressed for a predetermined time from the head position of each song controlled by the playback position control means. Reproducing means for reproducing, storing means for storing music data compressed for a predetermined time from the head position of each music reproduced by the reproducing means, and decompression for decompressing the compressed music data read from the storage means Means for controlling the movement of the pickup to the next music when the reproduction time of the music data compressed by the reproduction means has passed a predetermined time. An optical disk reproducing apparatus according to claim.

On the optical disk, time information and compression rate information of each music are recorded in, for example, a user TOC area.
When performing intro scan playback, the read time from the disc for each song for realizing playback for the designated time is calculated from the designated time and the compression ratio of each song. The music data compressed for a predetermined time from the head position of each song is reproduced, the music data compressed for a predetermined time from the head position of each reproduced music is stored in a memory, and the music data stored in this memory is stored in the memory. Will be played. When the reproduction time has passed a predetermined time, the pickup is moved to the head of the next music piece. As described above, by controlling the reading time from the disk, an intro scan in which the same playing time is obtained for each music piece can be realized.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in the following order.

A. Overview of recording / reproducing device b. Specific configuration of recording / reproducing device c. Description of recording system d. Description of reproduction system e. Introscan playback f. Basic recording / reproducing operation a. First, FIG. 1 is a block diagram showing a schematic configuration of an optical disk recording / reproducing apparatus as an embodiment of a data reproducing apparatus according to the present invention.

In FIG. 1, on a recording medium such as the optical disk 2, digital audio signals for a plurality of music pieces (a plurality of data files) compressed at several different bit compression rates are recorded. The recording signal is read in bursts by the optical head 3 in predetermined recording units (for example, 32 sectors + several sectors), and bit-compressed audio data is obtained via a decoder 21 for descrambling and error correction decoding. This compressed data is written to a memory 22 such as a RAM (random access memory),
2 is read out at a constant data rate, and the audio signal is reproduced through a decoder 23 for restoring (expanding) the bit compression on the recording side.

Here, along with the digital audio data of a plurality of music pieces having different bit compression rates, the time information and the compression rate information of each music piece (data file) are stored on the optical disc 2 by, for example, TOC (table of contents). ) Area or directory area.
Here, the time information in this case is address information indicating a start time and an end time of a music piece when recording and reproducing in a standard format (for example, a CD-DA format which is a so-called compact disc standard audio format). , This end time minus start time,
The amount of data recorded on the optical disk 2 is represented in standard time. The compression information is information indicating a ratio of (data amount before compression) / (data amount after compression). For example, when the standard straight PCM data is compressed to a data amount of 1/4. The compression ratio is set to 4. The compressed data is actually reproduced (playback of music, so-called playback) for a time obtained by multiplying the data amount represented by the standard reproduction time by the compression ratio.

A system controller 7 having a CPU (Central Processing Processor) and the like
By reading the time information and the compression ratio information recorded in the OC area and the like, obtaining the actual reproduction time (playing time) for each music (each data file) as described above, and adding these, the optical disc is obtained. The actual total playback time (total playing time, total playing time) of all the songs (previous file) in 2 is calculated. The calculated total playback time is displayed on the display unit 9 in accordance with a key operation (for example, an operation of a time display key) on the key input operation unit 8 or the like.

In the TOC area and the like of the optical disk 2, the standard reproduction time information itself, information on substantial reproduction time (performance time) obtained by multiplying a compression ratio for each music, and the like are recorded. You may do it.

B. Specific Configuration of Recording / Reproducing Apparatus Hereinafter, a specific configuration shown in FIG. 1 will be described. As the optical disk 2 rotated and driven by the spindle motor 1, a recordable / reproducible magneto-optical disk, for example, is used. However, in the case of reproduction only, an aluminum reflective film type optical disk similar to a normal CD (compact disk) can be used. An optical head 3 for performing recording and / or reproduction on the optical disk (for example, a magneto-optical disk) 2 includes, for example, a laser light source such as a laser diode, and an optical system such as a collimator lens, an objective lens, a polarizing beam splitter, and a cylindrical lens. It is composed of components and a photodetector having a light receiving section of a predetermined pattern. The optical head 3 is provided at a position facing the magnetic head 4 via the magneto-optical disk 2. When data is recorded on the magneto-optical disk 2, the magnetic head 4 is driven by a recording-system head drive circuit 16, which will be described later, to apply a modulation magnetic field according to the recorded data. By irradiating the track with laser light, thermomagnetic recording is performed by a magnetic field modulation method. The optical head 3
Detects a reflected light of a laser beam applied to a target track, and detects a tracking error by, for example, a so-called push-pull method. When reproducing data from the magneto-optical disk 2, the optical head 3 detects the focus error and the tracking error, and at the same time, detects the difference in the polarization angle (Kerr rotation angle) of the reflected light of the laser light from the target track and reproduces the data. Generate a signal.

The output of the optical head 3 is supplied to an RF circuit 5. The RF circuit 5 extracts the focus error signal and the tracking error signal from the output of the optical head 3 and supplies the extracted signal to the servo control circuit 6, and also binarizes the reproduction signal and supplies it to a reproduction decoder 21 described later.

The servo control circuit 6 comprises, for example, a focus servo control circuit, a tracking servo control circuit, a spindle motor servo control circuit, a thread servo control circuit and the like. The focus servo circuit performs tracking control of the optical system of the optical head 3 so that the focus error signal becomes zero. Further, the tracking servo control circuit performs tracking control of the optical system of the optical head 3 so that the tracking error signal becomes zero. Further, the spindle motor servo control circuit controls the spindle motor 1 so as to rotate the magneto-optical disk 2 at a predetermined rotation speed (for example, a constant linear speed). Further, the thread servo control circuit moves the optical head 3 and the magnetic head 4 to target track positions of the magneto-optical disk 2 designated by the system controller 7. The servo control circuit 6 that performs such various control operations supplies information indicating the operation state of each unit controlled by the servo control circuit 6 to the system controller 7.

A key input operation unit 8 and a display unit 9 are connected to the system controller 7. The system controller 7 controls a recording and reproducing system in an operation mode specified by operation input information from the key input operation unit 8. Further, the system controller 7 traces the optical head 3 and the magnetic head 4 based on the address information (time information) in sector units reproduced from the recording track of the magneto-optical disk 2 based on the header time, the Q data of the subcode, and the like. The recording position and the reproduction position on the recording track are managed. The display unit 9 displays information on the recording position or the reproduction position, information on the function selected by the key operation, and the like as necessary. Here, Table 1 shows contents (recording format) recorded as a so-called subcode Q channel signal in a lead-in area or TOC area on a recordable / reproducible disk such as the magneto-optical disk 2.

[0023]

[Table 1]

In Table 1, the item P of P / R indicates a pre-master portion which has been recorded and formed in advance as a so-called physical pit, and R indicates a recordable portion. The time information and the compression ratio information are stored in a rewritable user TOC (so-called U-TOC) area.
The index is recorded in the portion from N + 1 to 99. Here, N is a so-called BCD (Binary Decimal Number) and takes any value from 00 to 98. It is conceivable to write the above-mentioned compression ratio information in a so-called “zero-byte” in the U-TOC (TOC for a user), and a specific example is shown in Table 2.

[0025]

[Table 2]

In Table 2, the so-called "zero-byte"
Bit 7 (most significant bit) is used as a flag indicating overwriting (rewriting) protection of each music piece. When this bit 7 is "0", writing is prohibited.
The case of "1" is defined as writing permission. Bits 0 to 2 (lower 3 bits) of this so-called “zero-byte”
Is used to show information about the compression ratio. That is, bit 2 specifies the sampling frequency fs, bit 1 specifies the bit compression algorithm, and bit 0 specifies stereo / monaural. When bit 7 is "0", the standard CD-DA format sampling frequency of 44.1 kHz (or so-called CD-I or CD-R) is used.
The standard sampling frequency of a format such as OM XA is 37.8 kHz), and when “1”, the frequency is half that frequency. It is assumed that this sampling data is quantized by 16 bits, and the compression algorithm of bit 1 is that when "0", it is compressed to about 4 bits, which is 1/4
It is defined that when "1", the data is compressed to about 8 bits, which is 1/2. Bit 0 indicates “stereo” when “0” and monaural when “1”. These bits 2
From each value of 0, the compression ratio in each case as shown in Table 3 is obtained.

[0027]

[Table 3]

As apparent from Table 3, for example, the sampling frequency of bit 2 = "0" is the standard (44.1k
Hz or 37.8 kHz), bit 1 = about 8 of “1”
Using an algorithm that compresses to bits, bit 0 =
In the case of “0” stereo, the compression ratio is the smallest and is “2”. Conversely, the sampling frequency of bit 2 = "1" is half (22.05 kHz or 18.5 kHz)
Then, an algorithm for compressing to about 4 bits of bit 1 = “0” is used, and when the bit 0 = “1” is monaural, the compression rate is the largest, ie, “16”. In other combinations of each bit value, the compression ratio is “4” or “8”.

Here, the U-TOC (TO for user)
Table 4 shows a specific example of the recorded contents in C).

[0030]

[Table 4]

Table 4 shows a specific example of the recorded contents of the U-TOC at the time when four songs are recorded on the magneto-optical disk 2, and the start time (start time) is used as the time information.
And an end time (stop time). From the time information corresponding to the indexes B2 and B3, it can be seen that the recording has been performed up to the address position of 3 minutes 43 seconds 28 frames (block) in the standard reproduction time. Each information of the track, index, start time and end time in Table 4 is directly recorded and reproduced as the Q channel signal of the subcode as shown in Table 1 above. Also,
The compression ratio information includes bits 0 to 0 of the so-called “zero-byte”.
Based on the value of 2, it can be determined as shown in Table 3 above. Here, the standard reproduction time for each song is obtained by subtracting the start time from the end time, and the compression ratio of each song is 4 for the first song, 8 for the second song, 8 for the third song, and 8 for the third song. ,
Since 4 is selected for the fourth song, the value obtained by multiplying each of these compression ratios becomes the actual playback time (playing time, playing time) for each song. Such a calculation is performed by the system controller 7, and the total playback time (performance time) can be obtained by summing up the actual playback time for each music piece. In the example of Table 4, the time is 15 minutes 54 seconds 2 frames (block), and this numerical value is displayed on the display unit 9 for example.

Table 5 shows a generalized calculation of the actual reproduction time (performance time).

[0033]

[Table 5]

In Table 5, the actual reproduction time Tp of one song is the end time Te represented by the standard reproduction time.
By multiplying the result by subtracting the start time Ts from the compression rate k of the music, Tp = k (Te−Ts) can be obtained.

C. Description of Recording System Next, a recording system of the disk recording / reproducing apparatus will be described. An analog audio input signal A _IN from an input terminal 10 is supplied to an A / D converter 12 through a low-pass filter 11.
Is supplied to The A / D converter 12 quantizes the analog audio signal A _IN , and the obtained digital audio signal is supplied to an encoder 13 for high-efficiency encoding processing such as AD (adaptive difference) PCM. Also, an external digital audio signal may be supplied to the encoder 13 via a digital input interface circuit (not shown). The digital audio PCM signal input to the encoder 13 is
This is so-called straight PCM data that has not been subjected to compression processing or the like. As a specific example, similar to the standard CD (compact disk) format (CD-DA format), the sampling frequency is 44.1 kHz and the quantization bit rate is It is assumed that the number is 16-bit PCM data. The input audio PCM data is processed by the encoder 13 to have a high bit rate of 1/2 to 1/16 according to the sampling frequency, the bit compression algorithm, and the combination of stereo / monaural as described above. An efficiency coding process is performed. In the following description, compression is performed to a bit rate of approximately 1/4 (when the above-described compression rate is 4
Case), an example is given, but in addition, 1/2, 1/8,
The operation is basically the same in the case of compression to a bit rate such as 1/16.

Next, the memory 14 is controlled by the system controller 7 to write and read data. The memory 14 temporarily stores the bit-compressed data supplied from the encoder 13 and records it on the disk as necessary. Is used as a buffer memory. That is,
For example, in the data compression mode in which the compression ratio is 4,
Compressed data at a constant bit rate reduced to approximately 1/4 of the data transfer rate (bit rate) of the standard CD-DA format is continuously written to the memory 14. When this compressed data is recorded on the magneto-optical disk 2, it is recorded in a burst or discrete manner at the same data transfer speed under the same disk rotation speed (constant linear speed) as the standard CD-DA format. I have. That is, the time during which the signal is actually recorded in the recording mode is approximately 1/4 of the whole, and the remaining 3/4 time is a pause period during which no recording is performed. However, on the magneto-optical disk 2, the next recording is performed following the area recorded immediately before the pause period, and continuous recording is performed on the medium surface. Thereby, for example, a standard CD-DA
Recording of the same recording density and recording pattern as the format is performed.

For this reason, a standard CD is stored in the memory 14.
-Compressed data is read in bursts at a bit rate corresponding to the data transfer rate of the DA format, and the read compressed data is encoded by an encoder for performing interleave processing, error correction coding processing, EFM modulation processing, and the like. 15 is supplied. Here, in the data string supplied from the memory 14 to the encoder 15, one cluster composed of a predetermined plurality of sectors (for example, 32 sectors) is a unit that is continuously recorded in one recording, and when this is encoded, , A data amount obtained by adding several sectors for cluster connection to the data amount for one class. The cluster connection sector is set to be longer than the interleave length in the encoder 15 so that even if interleaved, data of other clusters is not affected.

The details of the recording in cluster units will be described later with reference to FIG. The encoder 15
As described above, the recording data supplied in a burst form from the memory 14 is subjected to an encoding process for error correction (parity addition and interleaving process) and an EFM encoding process. Also, a synchronization pattern and a so-called sub-coding portion are added at the same time, and the time information as described with Tables 1 to 4 and the like is added to the Q channel of the sub-coding in the U-TOC (TOC for user) area. And compression ratio information. The recording data that has been subjected to the encoding process by the encoder 15 is supplied to the magnetic head drive circuit 16. This magnetic head drive circuit 16
The magnetic head 4 is connected, and drives the magnetic head 4 so as to apply a modulation magnetic field according to the recording data to the optical disk 2.

The system controller 7 performs the above-described memory control on the memory 14 and continuously records the recording data read out from the memory 14 in a burst on the recording track of the magneto-optical disk 2 by the memory control. The recording position is controlled so that The recording position is controlled by controlling the recording position of the recording data read out from the memory 14 in a burst manner by the system controller 7 and controlling the control signal for designating the recording position on the recording track of the magneto-optical disk 2 by servo control. Circuit 6
Is performed by supplying the

D. Next, a reproducing system of the disk recording / reproducing apparatus will be described. This reproducing system is for reproducing the recorded data continuously recorded on the recording tracks of the magneto-optical disk 2 by the above-mentioned recording system. The recording signal is read from the magneto-optical disk 2 by tracing. Here, the magneto-optical disk 2 is the standard C
It is rotationally driven at the same rotation speed (constant linear speed) as the D-DA format, and the recording signal is read in a burst (discrete) manner at the same data transfer speed as the CD-DA format. Decoder 2
1 is supplied.

The decoder 21 corresponds to the encoder 15 in the above-described recording system, and performs decoding processing for deinterleaving processing and error correction processing on the reproduced output binarized by the RF circuit 5. Processing such as EFM demodulation processing is performed, and compressed data having a compression ratio of 4 is output in a burst at the same data transfer rate as the standard CD-DA format, for example. In addition, the above U-TCO
Based on the signal of the Q channel of the subcode in the (user TOC) area, the time information (start time, end time) is directly transmitted, and bits 0 to 2 of the so-called “zero-byte” are used.
, The compression ratio information is obtained. The reproduction data obtained by the decoder 21 is supplied to a memory 22, and the subcode information and the like are supplied to a system controller 7.

In the memory 22, writing and reading of data are controlled by the system controller 7, and reproduced data supplied from the decoder 21 in bursts at the same data transfer rate as the standard CD-DA format is written. Also, the memory 22 stores the reproduction data written in a burst at a constant bit rate, that is, approximately 1/1 of the standard CD-DA format.
4 is continuously read at the data transfer speed.

The system controller 7 controls the memory for writing / reading the reproduction data to / from the memory 22 and records the reproduction data written in a burst from the memory 22 by the memory control on the magneto-optical disk 2. The playback position is controlled so as to continuously play back from the track. The reproduction position is controlled by controlling the reproduction position of the reproduction data read out from the memory 22 in a burst manner by the system controller 7 and transmitting a control signal designating the reproduction position on the recording track of the magneto-optical disk 2 to the servo circuit 6. Is performed by supplying the

Compressed data obtained as reproduced data continuously read from the memory 22 at a transfer rate (bit rate) of approximately 1/4 of the standard is supplied to a decoder 23. The decoder 23 corresponds to the encoder 13 of the recording system, and reproduces 16-bit digital audio data by, for example, expanding the compressed data of 1/4 by 4 times (bit expanding).
The digital audio data from the decoder 23 is supplied to a D / A converter 24.

The D / A converter 24 converts the digital audio data supplied from the decoder 23 into an analog signal, and outputs an analog audio output signal A _OUT from an output terminal 26 via a low-pass filter 25.

Incidentally, it is desirable that the magneto-optical disk 2 used in such a disk recording / reproducing apparatus has a capacity capable of recording a stereo audio signal for about 60 minutes to about 74 minutes. For example, a data compression ratio of 4 is adopted. At this time, about 130 Mbytes are required. Further, in order to constitute a portable or pocket-sized recording and / or reproducing apparatus, it is desirable to use a disk having an outer diameter of 8 cm or smaller. Further, the track pitch and the linear velocity are the same as the CD, ie, about 1.6 μm, and the linear velocity is 1.2 to 1.
It is desired to be 4 m / s. As a disc satisfying these conditions, for example, the outer diameter of the disk is 64 mm, the outer diameter of the data recordable area is 61 mm, the inner diameter of the data recordable area is 31 mm, and the inner diameter of the lead-in area is 2 mm.
What is necessary is just to make 9 mm and the center hole diameter 11 mm. If this disc is housed in a disc caddy measuring 70 mm × 74 mm in length and width and supplied to the market, recording and reproduction on the disc can be performed by a reproducing device having a pocket size.

E. Introscan reproduction Next, introscan reproduction in the disk recording / reproducing apparatus will be described. In such a disk recording / reproducing apparatus, intro scan reproduction is performed as follows. In the intro scan reproduction, only the head portion of each music recorded on the magneto-optical disk 2 is sequentially reproduced for a predetermined time.

As described above, in this disk recording / reproducing apparatus, digital audio signals for a plurality of music pieces compressed at several different bit compression ratios are output from the magneto-optical disk 2.
The recording signal can be recorded in the optical head 3.
Read in a burst for each predetermined recording unit, and write the reproduced compressed data to the memory 22.
The data is read out at a constant data rate from the device to reproduce the audio signal. For example, in a data compression mode with a compression ratio of 4, compressed data at a constant bit rate, in which the data transfer speed of the standard CD-DA format is reduced to approximately 1/4, is recorded on the magneto-optical disk 2. Thus, the actual reproduction time of a song with a compression ratio of 4 is four times the reproduction time of data from the magneto-optical disk 2.
In this disk recording / reproducing apparatus, it is possible to record a plurality of data having different compression ratios in the same disk. Therefore, if the reproduction time from the magneto-optical disk 2 is made constant during introscan reproduction, In some cases, the actual playback time of a song may be different.

Therefore, in this disk recording / reproducing apparatus,
In the first example, each piece of music on the magneto-optical disk 2 for realizing a designated intro scan using the above-mentioned compression ratio information obtained from bits 0 to 2 of a so-called “zero byte” in the U-TOC area described above. By controlling the reproduction time of the music and reading the data of each music on the magneto-optical disk 2 for the calculated time, introscan reproduction in which the reproduction time of each music is constant is realized.

That is, the reading time T _D from the disk for each music piece for performing the intro scan reproduction at the specified time T _A is obtained by the following equation: T _D = T _A / K K: compression ratio. For example, when the data of each song is recorded at a compression rate as shown in Table 6, the read time of each song 01, 02, 03, and 04 on the magneto-optical disk 2 is set to 1 second, If they are set to 秒 second, 、 １ second, and 1 second, the intro playback time of all songs is equal to 4 seconds.
That is, since the track number 01 has a compression ratio of 4, if data is read from the magneto-optical disk 1 for one second, reproduction is performed for four seconds. Also, since the track number 02 has a compression ratio of 8, when data is read from the magneto-optical disk 1 for 1/2 second,
Playback is performed for seconds. Since track number 03 has a compression ratio of 8, when data is read from magneto-optical disk 1 for 1/2 second, reproduction is performed for 4 seconds. Since track number 04 has a compression ratio of 4, when data is read from magneto-optical disk 1 for 1 second, reproduction is performed for 4 seconds.

[0051]

[Table 6]

FIG. 3 shows an example of the control when the intro scan is performed in this manner. First, the song number N is (N =
1) (step 101), and the optical head 3 and the magnetic head 4 access the position of the first track of the (N = 1) music (step 102). And (N = 1)
The music data of the tune is reproduced (step 103). The playback time for which the playback time of this (N = 1) song was found is
It is determined whether the time T _D obtained by the above equation (T _D = T _A / K) has been reached (step 104), and the reproduction time T
Until _D is reached, the reproduction of the (N = 1) tune is continued.
When the playback time from the disc reaches T _D , (N = 1)
The reproduction of the tune is ended, and the tune number N to be reproduced is incremented (step 105). And step 101
The position of the (N = 2) th song is accessed (step 102), and the (N = 2) th song is reproduced (step 103). Then, (N + 2) -th whether the playback time of the song has reached T _D is determined (Step 10
4), until the reproduction time T _D, it continues the reproduction of (N = 2) th tracks. When the playback time from the disc reaches T _D , the playback of the (N = 2) th song is terminated, and the song number N to be played is incremented (step 10).
5). Hereinafter, the intro scan reproduction of the third and fourth music pieces is continued in the same manner.

FIG. 4 shows another example of control for performing introscan reproduction. In this example, bits 0 to 2 of a so-called “zero byte” of the U-TOC area described above are used.
Using the compression rate information obtained from the above, calculate the amount of data required to realize the specified intro scan,
By controlling the data to be read from the memory 22 by the determined data amount, introscan reproduction in which the reproduction time of each music piece is constant is realized.

That is, assuming that the data amount for performing the intro scan reproduction for the designated time is D _A , the memory 2 for each music necessary for realizing the designated intro scan is provided.
The data amount D _M of the read data from No. 2 is obtained by D _M = D _A / K K: compression ratio. By controlling the amount of data read from the memory 22 for each song to be the data amount D _M obtained in this way, introscan playback with a constant playback time for each song can be realized.

In FIG. 4, first, the song number N is (N = 1)
(Step 201), the optical head 3 and the magnetic head 4 access the position of the first track of the (N = 1) tune (Step 202). Then, the music data of the (N = 1) music is reproduced (step 203). It is determined whether the data amount of the music piece (N = 1) read from the memory 22 has reached the data amount D _M obtained by the above equation (D _M = D _A / K) (step 204).
The reproduction of the (N = 1) tune is continued until the data amount from reaches D _M. When the amount of data from the memory 22 reaches D _M , the reading of the data from the memory 22 is stopped (step 205), the memory 22 is cleared (step 206), and the music number N to be reproduced is incremented (step 207). . Then, returning to step 201,
(N = 2) The position of the tune is accessed (step 20).
2) Reproduction is started (step 203). And
(N = 2) The read data amount of the memory 22 of the music piece is D _M
Is reached (step 204), and the reproduction of the second piece of music is continued until the data amount from the memory 22 reaches D _M. When the data amount of the memory 22 reaches D _M , the reading of data from the memory 22 is stopped (Step 205), and the memory 22 is cleared (Step 20).
6) The music number N to be reproduced is incremented (step 207). Hereinafter, the intro scan reproduction of the third and fourth music pieces is continued in the same manner.

F. Basic recording / reproducing operation Next, a basic recording / reproducing operation by the recording / reproducing apparatus as described above will be described. First, recording data (data read from the memory 14) is clustered into a fixed number (for example, 32) of sectors (or blocks), and some sectors for cluster connection are provided between these clusters. It is in the form of being arranged. Specifically, as shown in FIG. 2, the class C is composed of 32 sectors (blocks) B0 to B31, and four connection (ringing) sectors L1 are provided between these clusters C.
To L4 are connected to the adjacent sector. Here, one cluster, for example, when recording k-th cluster C _k, the 32 sectors B of this cluster C _k
Not only 0-B31 but also three connecting sectors forward and one connecting sector backward, that is, two run-in block sectors L2 and L3 and one sub data sector on the cluster C _k-1 side. The recording is performed in units of a total of 36 sectors including the sector L4 and the sector L1. At this time, the recording data for these 36 sectors is stored in the memory 1.
4 to the encoder 15, and the encoder 15 performs an interleave process, so that a maximum of 108
The rearrangement of the distance of the frame (corresponding to about 1.1 sectors) is performed. For the data in the cluster C _k ,
It is well within the range of the ringing sectors L1 to L4 and does not affect other clusters C _k-1 and C _{k + 1} . Note that, for example, dummy data such as 0 is allocated to the sectors L1 to L3, and auxiliary sub-data is allocated to the sector L4, so that an adverse effect on the original data due to the interleave processing can be avoided. Here, as shown in FIG. 5A, the sectors B0 to B31 for the main data are 0000 0000 in an 8-bit binary system (two-digit hexadecimal number).
Sector numbers of (00H) to 0001 1111 (1FH) are respectively assigned, and 0010 0000 is assigned to the sector L1 of the ringing portion.
(20H), 00111101 (3DH) -00 for L2-L4
11 1111 (3FH) sector numbers are assigned.
Further, as the cluster, for example, 36 sectors including a ringing sector may be defined as one cluster.

[0057]

[Table 7]

Such a ringing sector is necessary for facilitating burst recording or overwrite recording. However, when recording all tracks continuously on a disk, specific ringing sectors are used. This is not necessary when a commercially available read-only soft disk is created. For example, adjacent data clusters C may be directly connected (with no ringing sector) as shown in FIG. 5B. In this case, both the data cluster and the recording cluster have 32 sectors.

Table 7 shows the head trace time per physical sector or per cluster actually recorded on the magneto-optical disk 2. This Table 7 is shown in FIG.
A value calculated corresponding to B is shown, and when a ringing sector is added as described above, each time becomes slightly longer. In addition, there are various other definitions of the compression ratio,
Somewhat different.

By performing such recording in cluster units, it is not necessary to consider mutual interference due to interleaving with other clusters, and data processing is greatly simplified. In addition, if recording data cannot be recorded normally at the time of recording due to defocus, tracking deviation, other malfunction, etc., re-recording can be performed in the above class unit, and if effective data reading cannot be performed during reproduction, , Re-reading can be performed in cluster units.

Incidentally, one sector (block) is 235.
23 bytes consisting of 2 bytes, 12 bytes for synchronization, 4 bytes for header, and data D0001 to D2336 from the beginning.
36 bytes are arranged in this order. Of the 12 bytes for synchronization in the sector structure (block structure), the first 1 byte is 00H (H indicates a hexadecimal number), followed by 10 bytes of FFH, and the last 1 byte is 00H. The next 4-byte header consists of minute, second, and block address portions, one byte at a time, followed by one byte for mode information. This mode information
This is mainly for indicating the mode of the CD-ROM, and the internal structure of the sector shown in FIG. 2 corresponds to the mode 2 of the CD-ROM format. CD-I is a standard using this mode 2.

The specific example of FIG. 2 further shows a format for recording compressed audio data.
From the beginning of the 336-byte area, an 8-byte sub-header, 18 sound groups SG01 to SG18 each having 128 bytes, a 20-byte space area, and a 4-byte reserved area are arranged in this order. 8 above
The byte subheader has a file number, a channel number, a submode, and a data type of 1 byte, which are arranged twice.

When such sector-structured data is recorded on a disk, the encoder 15 performs encoding processing including parity addition and interleaving processing, and performs EFM (8-14 modulation) processing. Given
Recording is performed in a recording format as shown in FIG.

In FIG. 6, one block (one sector) is composed of 98 frames from the first frame to the 98th frame, and one frame has a channel clock period T
588 times (588T), 24T in one frame
(+ Connection bit 3T) frame synchronization pattern part, 1
4T (+ connection bit 3T) subcode portion, and 54
4T data (audio data and parity data)
A part is provided. The data portion of 544T is 12
Byte (12 symbols) audio data, 4 bytes of parity data, 12 bytes of audio data, and 4 bytes of parity data are so-called EFM-modulated, and audio data in one frame is 24 bytes (that is, audio samples). One word of data is 1
(6 words, 12 words). The sub-code part is obtained by subjecting 8-bit sub-code data to EFM modulation, and is divided into blocks of 98 frames, and each bit forms eight sub-code channels P to W. However, the subcode portions of the first and second frames are block synchronization patterns S ₀ and S ₁ outside the EFM rule (out-of-rule), and the subcode channels P to W are shifted from the third frame to the third frame. It is 96 bits each for up to 98 frames.

The above-mentioned audio data is recorded after being subjected to an interleaving process. During reproduction, the audio data is subjected to a de-interleaving process so as to be audio data having a data sequence in a time sequence. Instead of the audio data, general CD-I data or the like can be recorded.

In the disk recording / reproducing apparatus shown in FIG. 1, the system controller 7 continuously increments the write pointer W of the memory 14 at a speed corresponding to the compressed data bit rate as shown in FIG. When the unread data amount of the compressed data stored in the memory 14 exceeds a predetermined amount _Mk or more, the read pointer R of the memory 14 is transferred according to the standard CD-DA format. The data is incremented in a burst at a predetermined speed, and is incremented in a predetermined recording unit (for example, 32 units).
Memory control is performed so as to read every sector). Accordingly, within memory 14, the data amount that can be written without destroying the non-read data, that is, the recording capacity is possible will be prevented below a predetermined amount (M _T -M _K).

Here, the recording data read out from the memory 14 in a burst manner is continuous on the upper recording track of the magneto-optical disk 2 by controlling the recording position on the recording track of the magneto-optical disk 2 by the system controller 7. The status can be recorded. Moreover, as described above, since a data write area of a predetermined amount or more is always secured in the memory 14, the system controller 7 detects that a track jump or the like has occurred due to disturbance or the like, and performs a recording operation on the magneto-optical disk 2. Even in the case of interruption, a return operation can be performed during that time, and the input data can be recorded in a continuous state on the recording tracks of the magneto-optical disk 2.

Next, in the reproducing system in the disk recording / reproducing apparatus shown in FIG. 1, the system controller 7 sets the write pointer W of the memory 22 to a standard CD as shown in FIG.
-While incrementing at a transfer rate in accordance with the DA format and writing in bursts, the read pointer R of the memory 22 is continuously incremented and read at a rate corresponding to the bit rate of the compressed data, and the write pointer W is read by the write pointer W. stop writing when attached to One follow the pointer R (writable area becomes zero), so that the unread data amount stored in the memory 22 writes becomes equal to or less than a predetermined amount M _L Perform memory control. Therefore, the predetermined amount M _L is always stored in the memory 222.
The reproduction data can be continuously read from the memory 22 while securing the above unread area.

The reproduction data written to the memory 22 in a burst can be reproduced by the system controller 7 in a continuous state on the recording track of the magneto-optical disk 2. Moreover, since always a predetermined amount M _L or more data read area in the memory 22 as described above is secured, with respect to the optical disk 2 to detect that the track jump or the like occurs due to disturbances such as the system controller 7 even when the interrupting playback operation can be continued the output of the analog audio signal by reading the playback data from the predetermined amount M _L or more data read area.

In a system for recording the compressed audio data of the small-diameter magneto-optical disk 2 as described above, the information of the wobbling component when the so-called pre-groove is previously cut on the magneto-optical disk 2 before recording. And record absolute time information (A
(IPT: Absolute Time in Pregroove) has been considered, and several formats have been proposed for entering time information in the AIPT and for inserting time information in a so-called header time portion. . However, in the above-described small-diameter disk system, the address on the disk or the address of the sector is replaced by the conventional so-called C
Even if the time is entered in minutes (minutes, seconds, frames) as in D and the like, there is not much merit, and the ringing area as described above is required. Therefore, it is not preferable to correct or display the time. Therefore, for example, the compression ratio is determined as shown in Table 6 above, and each sector number is assigned to each cluster as shown in Table 3 above. The data portion for actually reproducing the audio signal has the above-mentioned sector number. An 8-bit binary number (2 hexadecimal digits), 0000 0000 (00
H) to 0001 1111 (1FH). In this sense, since only sector data having the same sector number is sent to the memory 22 regardless of whether the disk is a read-only disk using an aluminum reflective film or a recordable disk using a magneto-optical recording medium film, etc. If the processing for display and the processing for total time display are performed, the processing can be shared. The actual playing time may be displayed by detecting the compression ratio information, calculating the product sum of the values in Table 6 above and the number of sectors or clusters, and displaying the result.

The present invention is not limited to the above-described embodiment, but can be applied not only to an optical disk recording / reproducing apparatus but also to a reproduction-only apparatus. The time information recorded on the recording medium is not limited to the start time and the end time, and the reproduction time and the actual performance time may be written in the U-TOC area. Also, an address may be recorded on the recording medium instead of the time information. In that case, the reproduced address may be converted into the time information. In addition to the time information and compression information, in addition to using the subcode Q channel signal,
For example, writing to a header portion or a sub-header portion in one sector in FIG.
The data may be written in a portion other than -TOC. Furthermore, the intro scan does not have to be performed sequentially from the first song, and the intro scan can be performed in a desired order by inputting an arbitrary order and controlling by the system controller.

[0072]

According to the present invention, the time information and the compression ratio information of each song are recorded on the optical disk, for example, in the user TOC area. When performing introscan reproduction, the designated time and the compression ratio of each song are determined. From this, the reading time from the disc for each music piece for realizing the reproduction for the specified time is calculated. In accordance with the reading time, each song is read from the disk for each song and reproduced. After a predetermined read time has elapsed, the pickup is moved to the beginning of the next song, and the next song is reproduced. As described above, by controlling the readout time from the designated time and the compression ratio of each music piece and moving to the next music piece, introscan reproduction with the same performance time for each music piece can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a disk recording / reproducing apparatus as an example of a data reproducing apparatus according to the present invention.

FIG. 2 is a diagram showing a format of a cluster structure which is a unit of recording on a recording medium.

FIG. 3 is a diagram showing the contents of each sector in the cluster structure of FIG. 2;

FIG. 4 is a flowchart used to describe an example of an intro scan playback operation in the disc recording / playback apparatus according to the present invention.

FIG. 5 is a flowchart used to describe another example of an intro scan playback operation in the disc recording / playback apparatus according to the present invention.

FIG. 6 is a diagram showing a format of a frame and a sector (block) in the standard of a so-called CD (compact disk).

FIG. 7 is a diagram showing a state of a memory controlled by a memory in a recording system of the disk recording / reproducing apparatus according to the present invention.

FIG. 8 is a diagram showing a state of a memory whose memory is controlled in a reproducing system of the disk recording / reproducing apparatus according to the present invention.

[Explanation of symbols]

 2 Magneto-optical disk 3 Optical head 7 System controller 13 Data compression encoder 14, 22 Memory 15 Encoder 16 Magnetic head drive circuit 21 Decoder 23 Data expansion decoder

Claims (1)

[Claims] 1. An optical disc reproducing apparatus for reproducing an optical disk on which compressed music data is recorded and on which the start position information of each song is recorded, comprises the steps of: Playback position control means for controlling the movement of the pickup to the start position; playback means for playing back music data compressed for a predetermined time from the start position of each song controlled by the playback position control means; Storage means for accumulating music data compressed for a predetermined time from the head position of each reproduced song; and decompression means for decompressing the compressed music data read from the storage means. When the reproduction time of the compressed music data exceeds the predetermined time, the optical pickup is controlled to move the pickup to the next music. Apparatus.