JPS586511A - Digital recording and reproducing system - Google Patents

Abstract

PURPOSE:To reduce final error, by recording a data from digital information with error detection and encoding together with a synchronizing signal added with a start and a stop bit at each block and performing a specified reproduction and error recorrection. CONSTITUTION:A start-bit 1 in 3-bit and a stop-bit 3 in 2-bit are added before and after an encoded data 2 in 32-bit obtained from digital information through error coding and recorded on a video disc 10 together with a synchronizing signal. A TV signal reproduced from the disc 10 is given to a synchronizing separation circuit 31, where an HD and a VD signal is separated and inputted to a level slice circuit 33. The data picked up via a timing generating circuit 32 is given to a block number count circuit 36 via a decision by majority circuit 34 and a separation circuit 35. If the count block has an error in the circuit 36, a signal is outputted to a code reproducing circuit 37. On the other hand, an error signal E is outputted from the circuit 37 to a data from the circuit 35 and reproduction is made again with a controller 38. Thus, final error can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recording and reproducing digital information using a recording medium capable of random data such as a video disc, and in particular to a digital recording and reproducing method that can reduce errors during reproduction. Several proposals have been made for recording and reproducing digital information in the form of television signals using video recording media. There is a method of inserting and recording digital information of a few bits to several tens of bits into one or more of the scanning periods, and another method of recording digital information of several tens of bits within the video signal period. However, in these methods, several tens of bits of digital information are recorded within one horizontal scanning period, resulting in poor response characteristics of the recording and reproducing circuits and problems with the recording medium. Recording and playback error rates are extremely high due to many factors such as performance and dust.

Even with powerful repeat detection and correction encoding schemes, it is often difficult to correct errors.

An object of the present invention is to provide a digital recording and reproducing method that can reduce the occurrence of errors.The purpose of this invention is to provide a digital recording and reproducing method that can reduce the occurrence of errors. and record it on the recording medium along with the synchronization signal. During playback, the number of blocks is counted from the start bit and stop bit, and the synchronization signal is counted. If scissors occur when reproducing the original digital information from the encoded data, the number of blocks and the count of the synchronization signal are counted. Then, the position on the recording medium where the error occurred is determined and replayed.

Therefore, according to the present invention, there is an advantage that final errors can be extremely reduced by re-correcting by replay when an error occurs.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the recording signal format according to the present invention, in which 3-bit start bit J is placed before and after 32-bit encoded data 1 (B1 to Bl?) obtained by error detection and correction encoding of digital information. (A, ~Cm1) and 2-bit stop pitch) J (c1~Cm
), and each of these data has a length of 0.5H per bit, where one horizontal scanning period is expressed as IH, and has a high degree of redundancy to sufficiently cope with pulse-like noise. I'm taking it. Therefore, the start bit l is 1
．． 5H1 encoded data 2 will be recorded at 18.5H and stop bit 1 will be recorded at IH. One unit of the recording signal as shown in Figure 1 is called a block. The position within the video signal period of horizontal scanning line number j, j+1, j+2°...
- The following table shows the relationship with (j-1, 2,...).

Next, the configuration of the second recording circuit will be explained with reference to FIG.

First, horizontal synchronization (g
The signal HD and the vertical synchronization signal VD are separated and become a reference synchronization signal for the timing generation circuit 23.

The timing generation circuit 2B first extracts Virat's digital information from the digital information generation circuit 24 and transfers it to the encoding circuit 25. The encoding circuit 25 performs error detection and correction encoding on the digital information of 2 bits, and encodes the N bits (first
In the example shown in the figure, a start bit and a stop bit are added by the adder circuit 26, resulting in a recording signal in the format shown in FIG. These operations are completed until the horizontal scanning line of the video signal period to be recorded is selected. Finally, the -timing generation circuit 23 generates a horizontal synchronization signal (-) and 0.5H timing No. 48 and an insertion gate signal, extracts data bit by bit from the output of the start/stop bit addition circuit 2#, and mixes the data. Television signal (including synchronization signal) in circuit 21
The signal is recorded on the video signal track of the video disc 1° which is controlled by the timing generation circuit 23. The above operations continue until there is no more digital information to record.

Next, the configuration of the reproducing circuit will be explained using diagrams W&3.

The television signal reproduced from the video disc 10 recorded as described above is guided to the synchronization separation circuit 31, where it is separated into an HD signal and a VD signal, and at the same time is sent to a level slice circuit 3J that shapes the waveform of the digital data. The digital data is input and extracted by a sampling gate signal from the timing generation circuit 32. This data is sampled, for example, three times in the majority decision circuit 34 and is sequentially shaped into complete 1-bit data based on majority consensus, and then input to the start/stop bit separation circuit 15.

The start bit/stop bit separation circuit J5 first detects a start bit, stores bit information that is sent one after another in a form with the start bit removed, and finally detects a stop bit and divides the block into several stitches - several circuits. 36.

The block number counting circuit 36 counts one block for the first time using these stop bits. If there is an error in the number of bits, an error signal or count value is sent to the controller 1t. On the other hand, the encoded N-bit data separated by the start-stop bit separation circuit 35 is input to the code regeneration circuit 17, where errors are detected, and an error signal E and a no-error signal E are output.

is provided to controller 38. At the same time, the vertical synchronization signal counting circuit 39 counts the number of VD signals. In this case, the position of the block being reproduced can be known from the outputs of the number circuits 36 and 39. Therefore, the controller Hikimutsu Tsubaki 3
8, when an error occurs in the digital information reproduced by the code reproducing circuit 31 and the error signal E is input.

Stitch number circuit 36. The reproduction head for the Vistar in which the error has been detected is returned to its position from the output of II to interrupt reproduction, and the circuit shown in the third figure is controlled to correct the error again.

As described above, R: According to the present invention, by replaying a block in which an error has occurred.

The error rate can be significantly improved. Also.

Since the position during playback can be easily determined, it is also possible to replay desired specific information related to the occurrence of an error.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a recording signal format in one embodiment of the present invention, and FIGS. 2 and 3 are diagrams showing the configuration of a recording circuit and a reproducing circuit.

Claims (2)

[Claims] (1) A recording medium in which encoded data obtained by error detection and correction encoding of digital information is inserted into the video signal period of a television signal by adding a start bit and a stop bit to each block, and can be randomly accessed along with a synchronization signal. Separate the recording bits and stop bits and synchronization signals, reproduce the original digital information from the encoded data, count the number of blocks of encoded data from the start bits and stop bits, and count the synchronization signals. However, if an error occurs when reproducing the original digital information from the encoded data, the position on the recording medium where the error occurred is determined from the number of blocks in the rotor and each count value of the synchronization signal during encoding. A digital recording and reproducing method characterized by comprising a reproduction circuit that reproduces that position again. (2) The digital recording and reproducing system according to claim 1, which uses a video disc as a recording medium.