JPS623469A - Multichannel pcm recording and reproducing device - Google Patents

Abstract

PURPOSE:To execute sufficiently the revision and the correction for a long burst error in the width direction or the travelling direction of a tape by making random the memory area of respective channels in the travelling direction of a memory media. CONSTITUTION:A recording signal processing part X is composed of a recording encoder 9 to code a signal 8 and a modulator 11a to modulate the coded signal. On the other hand, a reproducing signal processing part Y includes a demodulator 16a to demodulate the recorded data, a decoder 20 to execute the revision and the correction by the coded parity, etc., and a D/A converting device 21 to convert the digital signal to the analog signal. At the processing part X, a distributing device Z to be able to output at the optional time the data for respective channels is provided. The recording areas of respective channels, for example, 3, 4, 5 and 6 are obtained at random in the scanning direction of recording media 7. Thus, the revision and the correction can be sufficiently executed for the long burst error.

Description

[Detailed description of the invention] [Industrial application field] This invention is for stereo recording, playback, and karaoke recording.

The present invention relates to a multi-channel PCM recording and reproducing apparatus that records or reproduces multi-channel recording or recording using a fixed head or a rotary head.

[Conventional technology]

Two types of PCM magnetic recording and reproducing devices have been announced: a fixed head type and a rotating head type. If multi-channeling is considered for the former type, the track configuration will be as shown in Figure 1. becomes. In this case, multi-channel means that each channel of the input source can be recorded and played back completely independently. Therefore, the signal of each channel cannot be recorded in combination with other channels (in word units). As a result, as shown in Figure 1, it is necessary to record one channel information on one track on tape 1, and the channels have independent recording areas 2, 2, etc. was. In addition, this multi-channel system can be achieved using a rotating head type PC.
FIG. 2 shows a recording track configuration when considering use in an M recording/reproducing apparatus. In FIG. 2, 7 is a tape (recording medium), and on this tape 7, as an example, a pattern is shown when 4 channels of multichannel recording are performed, and recording areas 3 to 6 are for channels 1 to 4. Compatible with up to now. In this method, one channel is independent (continuous) in the tape width direction.
It has a recording area.

[Problem that the invention seeks to solve]

Incidentally, FIG. 3 shows the error distribution in the tape width direction in the case of the rotary head method. As you will see, the error rate is the best at the center of the tape,
The error rate gets worse as you go to tape edge. Considering this in relation to each channel in FIG. 2, recording areas 3 and 6 corresponding to channels 1 and 4 are near the tape edge and use areas with a poor error rate. Therefore, recording area 4.5 is a part with a good error rate near the tape center, whereas recording area 3.
6 is a part where the error rate is always poor, and it cannot be said that each channel is under the same conditions.

Furthermore, when a burst error occurs in the tape running direction, considering both of the above methods, if the burst length in the tape running direction exceeds the individual correction ability, the output of the channel where the burst occurred will produce abnormal noise. occurs, or mute processing occurs again.

SUMMARY OF THE INVENTION An object of the present invention is to provide a multi-channel PCM recording and reproducing apparatus having a function of equalizing the above-mentioned error distribution or long burst errors in the tape width direction for each channel.

[Means for solving problems]

The present invention includes a recording signal processing section In a multi-channel PCM recording and reproducing apparatus, the multi-channel PCM recording and reproducing apparatus includes a decoder 20 that performs correction, correction, etc. based on converted parity, etc., and a reproduction signal processing section Y that includes a D/A converter 21 that converts a digital signal into an analog signal. The recording signal processing section
The feature is that the running direction is random.

〔Example〕

An embodiment of the present invention will be described below using a recording signal processing section X (FIG. 4) of a rotary head type multi-channel PCM recording and reproducing apparatus, taking as an example the case where the number of channels is four.

In FIG. 4, 8... is an input stage, for example, an A/D converter 8a is used to convert the A/D converter 8a from the line-in of each channel.
This is a signal that is input after being D-converted. 9 is a recording encoder for encoding and interleaving this input signal 8, and 10 is a RAM for recording this encoded signal. Up to this writing operation to the RAM, real-time processing is performed independently for each channel. 2 is a distribution device that can output data for each channel at any time; 12 is a distribution device for each of the RAMs 10 and
This is a timing circuit that controls the R/W processing (reading and writing) of RAM 10. It can operate no matter what order the read timing of this RAM 10 is instructed for each channel. It looks like this. Channel scramble information 1 indicates the order of the channels.
3.

The data of each channel 1 to 4 whose timing is controlled by the timing circuit 12 that controls the R/- of the RAM 10 is synthesized by the multiplexer 11, and then modulated by the modulator 11a as the recording signal 14. It is output to the head 15. The channel scramble information 13 is input to the timing circuit 12 and is recorded on the tape 1 or 7 as subcode information, for example, in a separate system. Output of timing circuit 12 (RAM 1~
FIG. 5 shows a timing chart of 4 READ timing) and an example of its recording pattern. In FIG. 5, (A) is a clock pulse generated every 180° of helical scanning, (B) and (C) are clock pulses generated every 180° of helical scan.

(D) and (E) are RAM 1-RAM in Fig. 4
An example of reading timing pulses up to 4 is shown. These reading timing pulses (B), (C),
In (D) and (E), the readable signal becomes active in the high level portion, and the period is randomly shifted from the clock pulse (A), and the clock pulses do not overlap with each other in time. (F) is multiplexer 1
1 shows the final channel arrangement mixed in 1. Also, the trunks Tr, ~TrB+ shown in (F) of FIG.
FIG. 6 shows the recording area of the channel of the tape recording pattern in No. 3. In this example, channels 1 to 4 are scrambled such that a toggle operation is performed for each track. Therefore, if we consider the area divided into four in the tape width direction, the same channel data will be divided into four areas.
It will be written every other track.

FIG. 7 shows the reproduction signal processing section Y on the reproduction side. In the figure, 16 is an input section for PCM data sliced by the demodulation circuit 16a, and 17 is an input section for subcode data that is also demodulated, and channel scrambling information is included in this subcode. Reference numeral 18 denotes a channel distributor, which separates the PCM data inputted from the input section 16 for each channel based on the channel scrambling information of 15, and outputs it to the next stage RAMs 19, 19, . . . . 20 is a decoder that operates independently for each channel and performs correction and correction based on encoded parity and the like. The output digital signal of this decoder 20 is D/A
The converter 21 converts it into an analog signal.

When performing multi-channel PCM recording and playback with the above configuration, if we focus on one channel, the recording will be distributed at various positions in the tape width direction, which will eliminate uneven error distribution. It is possible, and furthermore,
By increasing the capability of the correction system for burst errors in the tape running direction, it is possible to realize a system that can sufficiently correct and correct even if there is a burst error of infinite length.

In addition, although the above example shows the case of the rotating head method,
Even in the case of a fixed head method, this channel scrambling is performed by dividing subcode information into blocks of a certain length.
The above effect can be obtained sufficiently effectively by means such as adding the channel information to the channel information. Further, as for the scrambling method, the permutation method explained in the embodiment, completely random scrambling, etc. can be considered and can be set arbitrarily.

〔Effect of the invention〕

As described above, according to the present invention, since the recording area of each channel is made random with respect to the running direction of the recording medium,
Even in the case of long burst errors in the width direction or running direction of the tape, the errors are made uniform for each channel, making it possible to sufficiently correct and correct them.

[Brief explanation of drawings]

Figure 1 shows the recording format of fixed head tape.
FIG. 2 is a recording format of a 4-channel rotary head type tape, FIG. 3 is a graph showing the error rate distribution in the tape width direction of a rotary head type, and FIG. 4 is a block diagram of a recording system according to an embodiment of the present invention. FIG. 5 is a graph of the timing pulses in FIG. 4, FIG. 6 is an explanatory diagram of the recording pattern on the tape, and FIG. 7 is a block diagram of the reproduction system. 8...Signal, 9...Recording encoder, lla...Modulator, X...Recording signal processing section, 16a...Old...Demodulator, 20... ...Decoder, 21...D/A converter, Y...
Reproduction signal processing unit, Z... distribution device, 3.4, 5
．． 6... Recording area, 1.7... Recording medium. Calculation 1st staff recruitment 2nd class? ＋、Iwagl Sleeping Keyaki Calculation 3 Wandering 9 Figure

Claims (1)

[Claims] a recording signal processing section comprising a recording encoder that encodes a signal and a modulator that modulates the encoded signal;
It has a demodulator that demodulates recorded data, a decoder that performs correction, correction, etc. based on encoded parity, and a reproduced signal processing unit that includes a D/A converter that converts digital signals to analog signals. multi-channel PCM
The recording/reproducing device is characterized in that the recording signal processing unit includes a distribution device capable of outputting data for each channel at an arbitrary time, and the recording area of each channel is made random with respect to the running direction of the recording medium. A multi-channel PCM recording and playback device.