JPS58203608A - Disk reproducing device - Google Patents

Abstract

PURPOSE:To prevent the generation of click noises or abnormal sounds, by releasing the muting state of a reproduced output after the lapse of a time longer than a prescribed time necessary for processing the data on the reproducing program information. CONSTITUTION:The output data of a decoding circuit 13 is supplied to an interpolation circuit 14 to receiver the interpolation. The circuit 14 receives a muting command signal CM and a muting release signal CM' from a system controller 8 and performs a muting control over a reproduced voice. The output data of the circuit 14 is supplied to a D/A converting circuit 15, and a reproduced audio signal is transmitted through the output terminal of the circuit 15. In addition, the circuit 14 gives a correction with an interpolation process to the one added with a pointer code among audio data. The audio data which has received the interpolation process undergoes a D/A conversion through the circuit 15. Then a reproduced audio signal is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc playback device used for producing a disc on which digital φ data is recorded, particularly in the case of a digital audio disc. The present invention relates to an improved disk playback device that can prevent click noises and abnormal sounds from occurring at the start of playback when playing back a desired one from the top of the page. ) Program information data such as digitized audio signal data and error correction data is stored on a rotating disk-shaped recording medium.
A digital audio device that records various data such as synchronization data, address data, etc. to form a recording track.
A digital audio disc system is a system that creates a disc and uses a disc playback device to internally reproduce the digital audio disc on which digital data is recorded to obtain a playback audio signal. This system has been proposed as a system that can be obtained relatively easily. 1. In a disc playback device that plays back such a digital audio disc, the playback program information data read from the digital audio disc is If a code error occurs, large lick noise will occur in the reproduced audio signal.

In general, on digital audio discs, code errors that occur when recording program information data are inevitable, although the probability is low, and
When reading digital data, large-scale code errors can occur due to the influence of fingerprints and scratches on the disc surface7. Therefore, in the digital-audio e-disc contention system, there is a method to correct these code errors. , an error correction method using a technique called cross interleaving is adopted. The feature of the error correction method using this cross-interleaving method is that it adopts a two-stage configuration in which error correction data is prepared in an Ω system, and that interleaving is applied between the two stages. By using a Reed-Solomon code and skillfully combining the Reed-Solomon code with interleaving, it is possible to provide an extremely powerful error correction ability. For this reason, the "disk" Jugyu device is capable of handling playback program information data obtained by reading from a digital audio disc on which program information data including error correction data added by the cross-interleaving method is recorded. , is provided with error correction means for performing error correction over the Ω stage using the error correction data of the co-systems included therein.

and.

As a result of the provision of such error correction means, the reproduction program information data obtained by reading from the digital audio disk is not converted into a reproduction audio signal in real time, but is converted into a cross-interleaved audio signal.
The reproduced audio signal is delayed by the time required for error correction using the interleave method, that is, the interleave delay time. .

On the other hand, the program information data recorded on such digital audio discs is usually accompanied by address data, and when played back by a disc playback device, this address data is also recorded. It is possible to selectively reproduce desired program information data. That is, the information reading means is put into a search operation state, and the reproduced address data included in the obtained reproduced signal is compared with the designated address data, and the information is set in one direction of the information reading means so that they match. Position control is performed with fast forwarding, fast forwarding in the reverse direction, etc., and then the program information data can be reproduced from the position corresponding to the specified address data by setting the normal reproduction operation state. in this case,
The reproduced address data is reproduced regardless of the interleave delay time described above and used for position control of the information reading means, but when the reproduced address data is decoded,
When the information reading means in the search operation state is made to reach the destination which is the location of the specified address data,
The information reading means gradually approaches the destination while repeating the operation of passing over the destination and then going back. In other words, it converges and reaches its destination. During the convergence operation of the information reading means, program information data near the destination is also read and supplied to the above-mentioned error correction means, where it is converted into reproduced audio No. 18 with an interleaving delay time. The program information data also has the disadvantage of producing click noise or abnormal sounds that are emitted prior to the reproduced sound that is obtained.

For example, playback from the beginning of the recording section N of the nth program information data in the recording track T on the digital audio disk as shown in FIG.
When so-called cue reproduction of the n-th program information data is performed, the information reading means in the search operation state draws a trajectory p in FIG. 1. That is, the information reading means reads the recording part N of the n-th program information data and the part where the immediately preceding program information data is not recorded, in other words, the recording part N-/ of the n-th program information data. The operation of passing back and forth through the boundary between the recording section N and the silent section e is repeated, and the reciprocating operations are converged to record the nth program information data at the recording section N.
reaches position p/ at the beginning of.

At this time, the information reading means reads the address data corresponding to the beginning part of the recording section N of the nth program information data at position pl, and in this case, this address data is designated as the specified address data. Therefore, at this point, the information reading means detects that it has reached the destination and enters the normal playback operation state, enters the recording section N of the nth program information data again, and writes the nth program information data there. The beginning part 1.1' is read from the beginning <1, so that the nth program information data is reproduced from the beginning part.

In this case, a reproduction audio signal is obtained for the n-th program/information data read after the information reading means is brought into the normal reproduction operation state, and before the reproduction sound is emitted, the information reading means is placed in the position. During the convergence operation to reach p/, the program information data read from the recording section N and supplied to the error correction means is delayed by the interleave delay time in the error correction means (for example, /
The signal is delayed by 3.5 msec) and converted into a playback audio signal to produce an audio output, which results in click noise or abnormal sound.

In view of the above, the present invention provides a method for reproducing arbitrary program information data from the beginning of a disc on which digital data is recorded, by performing processing that requires one hour of delay, such as error correction, for the reproduced program information data. To provide a music playback device which is designed to prevent the generation of click noises and abnormal sounds even when the music is played. Examples of the present invention will be described below.

FIG. Ω shows a main part of an example of a disc playback device according to the present invention. In the figure, / is a disk and a digital
Address data, which is data, is created and program information data is recorded, for example, on a digital audio disc as described above. This disk/is given a predetermined rotation by a motor tacho for disk rotation.The program information data and address data recorded on the disk/ are read by an information reading means, e.g.
This example is the case of an optical disc playback device.

This optical head 3 emits a laser beam onto a disk, and converts the reflected laser beam modulated according to the program information data and address data recorded on the disk into a reading laser. Uke is something that is received as light. The reading/receiving laser beam from the optical head 3 is guided to the light-receiving element, where photoelectric conversion is performed, and reproduction signals are quickly obtained for the read program information data and address data. It will be done. This reproduced signal is converted into a proper digital signal representing the read program information data and address data by the waveform shaping circuit S, and then supplied to the decoder 6. From the decoder B, the reproduced program information data S is obtained and the reproduced address book data Q is detected5, and
Reproduction address data Q is supplied to the first register 7 and held. Reproduction address data Q is read out from the first register 7 at a predetermined timing based on the control signal CN from the system controller g, and is supplied to one input terminal of the arithmetic circuit 9.

Reference numeral 10 denotes a keyboard, and key manual data from this keyboard 10 is supplied to the system controller g.

The system controller g receives the key manual data K and generates designated address data Qx, which is supplied to the second register // and held. 2. The designated address data from this second register // Qx is supplied to the second input terminal of the arithmetic circuit. The arithmetic circuit performs a comparison operation between the reproduced address data Q and the designated address data Qx, and based on the result of this operation, the arithmetic data P is immediately supplied to the system controller g. The system controller g sends a control signal Cc to the optical head 3 to cause the optical head 3 to perform various operations such as normal re-main operation, forward fast forward, reverse fast forward, /track advance jump, /track return jump, etc. Supplied. /2 is a timer circuit, which has a set time of 73 msec, for example.
After the calculation data P from the calculation 1i=il path 9 indicates that the reproduced address data Q and the specified address data Qx match, it is activated by the timer activation signal TS sent from the system controller. and when the set time has elapsed after startup, an overflow signal To
is supplied to the system controller g.

On the other hand, the reproduced program information data S from the decoder B is supplied to a decoding circuit/3 having an error correction function. The decoding circuit /3 constitutes an error correction means using a cross-interleave method, the details of which will be described later. The output data of the decoding circuit /3 is supplied to the interpolation circuit /lI for interpolation. Also, this interpolation circuit /9 receives the muting command signal C from the system controller g.
Upon receiving the muting release signal CM'f and the muting release signal CM'f, muting control is performed on the reproduced audio. The output data of the interpolation circuit /4' is supplied to a digital/4-analog conversion circuit /S, and a reproduced audio signal is sent from its output terminal.

Here, an example of the decoding circuit/3 will be explained with reference to FIG. As shown in FIG. 8, an example of the decoding circuit/3 is configured to include a multiplexer/A, a first decoder/B, a dinterleave delay element group/AC, and a second co-decoder/B. Ru. The multiplexer/Otsu A receives the audio data S, -S code, and the first error correction data P7-P in the playback program information data S from the decoder 6 shown in FIG.
q and second error correction data Q/~Q<= are derived.

The first decoder/B is the audio data S/~521I derived from the multiplexer/B and the first error correction data Pt.
=P4I is subjected to error correction using the λ-th error correction data Q/~Q41, and the error correction is performed, or the pointer code is added and the sentence audio data Sl'~S
2'l' and first error correction data P/' to PII' are generated. The dinterleave delay element group/Otsu C receives the data from the first decoder/Otsu B, that is, the audio data Sl' to 8.
2q' and the first error correction data Pl' to Pti', respectively. A dinterleave delay is applied to the data. The total interleave delay time, which is the sum of the respective delay times of delay elements Dl-Dsg, is, for example, /3.
! ; It is set to m seconds. The λ-th decoder/B is the delay element D/-02 of the dinterleave delay element group/C.
The first error correction data P,
Error correction is performed using ``//~Pv'' to create audio data T/~TJ9 that has undergone error correction or has a pointer code added. Audio data TI=T2'l created in this way is supplied to the interpolation circuit shown in FIG.

The interpolation circuit /lI performs correction by interpolation processing on the audio data T/-'r24f to which the pointer code has been added. The interpolated audio data is then digital-to-analog converted by a digital-to-analog conversion circuit/S to obtain a final reproduced audio signal.

Next, as shown in FIG. 9, it is assumed that the disk / has a recording track T formed thereon similar to that shown in FIG.
A case will be described in which the above-described disc reproducing apparatus according to the present invention reproduces the n-th program information data in the recording track T on the disc from the beginning of the recording section N. In this case, first, key input data K is supplied from the keyboard 10 to the system controller g, which instructs the optical head 3 to be positioned at the beginning of the recording section N of the nth program information data.
The system controller g receives this key manual data K, sends a muting command signal CM to the interpolation circuit/g, and causes the interpolation circuit/lI to mute the playback audio signal as well as the playback audio. In addition to performing the operation, the second register // is
Specified address data Qx whose content is address data corresponding to the beginning of the recording section N of the n-th program information data is supplied. And the Ωth /dister/
/, this specified address data Qx is supplied to the arithmetic circuit. At this time, the first register 7 is supplied with the reproduced address data Q obtained from the reproduced signal from the light-receiving element section, and this is also sent as the control signal CN from the system controller. Arithmetic circuit 7
supplied to Then, in the arithmetic circuit 9, arithmetic operations are performed on the specified address data Qx and the reproduced address data Q. If the two addresses and data do not match, a control signal Cc is supplied from the system controller g to the optical head 3, and the optical head 3 performs a forward or reverse fast-forward operation, track advance, or return jump operation. etc. is set to a search operation state. . When the optical head 3 is in the search operation state, each time the optical head 3 reads address data on the disk, a comparison operation is performed between the reproduced address data Q and the designated address data Qx in the arithmetic circuit W. The calculated data P based on the calculated result causes the system controller to change the content of the control signal Cc from the roller g, so that the optical head 3 position control is performed. The optical head 3 in the search 4TI+ operation state is
A convergence operation is performed by repeating the operation shown in the figure, and the target position p/ of the beginning of the recording section N of the n-th program information data is reached. During this convergence operation, the program information data read from the recording section N by the optical head 3 is supplied as reproduced program information data S to the decoding circuit/3 constituting the error correction means.

Then, the optical head 3 reads address data corresponding to the beginning part of the recording section N of the nth program information data at position p/, and in this case, this address data
Since the data is specified address data Qx,
At this point, the reproduced address data Q matches the designated address data Qx, and the control signal C from the system controller g is triggered by the calculation data P from the calculation circuit 9 indicating the match.
The content of c is a control signal for returning the optical head 3 to the silent portion e by a /track return jump operation. As a result, the optical head 3 performs a /track return jump operation, and the silent part e (D (i'f).

Return to the place pco. This position p[lambda] is about 2 to 0.3 seconds apart from the position p/ to the /track portion, and therefore to the optical system in the normal reproduction operation state, in terms of scanning time by the radar 3. When the optical head 3 is shamped back to /track, the control signal cc from the system controller g causes the optical head 3 to perform a normal playback operation, and the timer circuit 7.2 is sent from the system controller to the control signal cc. The timer start signal Ts is supplied to the timer circuit /2, and the timer circuit /2 is started.

In this way, the optical head 3, which has been returned to the position p, 2 of the silent part e and is in the normal playback operation state, is moved back to the position ig.
From p2, the n-th program information data is entered into the recording section N, the n-th program information data is read from the beginning, and the n-th program information data is reproduced from the beginning.

In this case, the output terminal of the decoding circuit/3 is provided with the n MS that is read after the optical head 3 is brought into the normal playback operation state.
Before the error correction of the eye program information data is obtained, the program information data read while the optical head 3 is performing a convergence operation to reach the position p/ is sent to the decoding circuit 73. The output data R obtained by passing through is delayed by the delay time required for error correction in the decoding circuit /3, f, ql, and the total interleaving delay time of 73.3 msec, σ, and is obtained by Since the total interleaving delay time (/3 m seconds) is longer than the setting time of timer circuit/2 (/m seconds), output data R is obtained and supplied to the interpolation circuit/G. At this time, the interpolation circuit/g is in a muting operation state, and muting is applied to the reproduced audio based on this output data R.

Therefore, the program information data read while the optical head 3 is performing a convergence operation to reach the position pl,
4. For this purpose, the set time of the timer circuit /2 is required for error correction in the decoding circuit /3. time, that is, the total interleave delay time.

The timer circuit 7.2 is then activated when the optical head 3 returns to position p2/track return jump is performed.
generates an overflow signal To and supplies it to the system controller g when the set time of /3 msec has elapsed, and the system controller g receives this overflow signal To and generates a muting release signal CM', This is supplied to the interpolation circuit. , the interpolation circuit/g receives the muting release signal CM' and releases the muting on the reproduced audio.b The muting is released while the optical head 3 is in normal playback operation and scanning the silent part e. Therefore, thereafter, based on the n-th program information data read after the optical head 3 is put into the normal playback operation state, the playback audio is sequentially obtained from the beginning.

As explained above, according to the disc playback device according to the present invention, strong error correction that involves a delay time, such as error correction using a cross-interleaving method, is performed on the playback program information data from a disc on which digital data is recorded. In addition to obtaining a high-quality reproduced audio signal, it is also possible to reproduce any program information data recorded on the disc from the beginning.
A desired playback output can be obtained without generating any preceding click noise or abnormal sound.

[Brief explanation of drawings]

FIG. 1 is a diagram used to demonstrate cue playback of program information data from a disc, FIG. 2 is a system diagram showing essential parts of an example of a disc playback device according to the present invention, and FIG. FIG. 9 is a system diagram showing in detail a part of the main part of an example of the disc reproducing apparatus according to the present invention shown in the figure, and is a diagram used to explain the operation of the disc reproducing apparatus according to the present invention. In the figure, / is a disk, 3 is an optical head, O is a tecoder,
7 is a first register, g is a system controller, 9 is an arithmetic circuit, // is a second register, / is a timer circuit, /3 is a decoding circuit, and /l is an interpolation circuit.

Claims (1)

[Claims] Reproduction 1 obtained through an information reading means from a disk on which address number data and program information data are recorded
Detecting the reproduction address data in the word, the information reading means is placed in a search operation state until the reproduction address data becomes predetermined address data related to the recording section of the desired program information data. At the same time, 1. The playback program information data in the playback signal also puts the playback output into a muting state, and the playback address and
When the data reaches the predetermined address data, the information reading means is moved to a portion where no program information data is recorded immediately before the recording portion of the desired program information data, and then the normal playback operation state is resumed. none,
Furthermore, after a predetermined time period or more required for processing the reproduction program information data has elapsed, the muting state of the reproduction output is canceled, so that the reproduction output of the desired program information data can be performed as soon as possible. A disc playback device that allows you to obtain