JPH0680556B2 - Digital signal transmission method and processing apparatus thereof - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for transmitting a digital signal between apparatuses for recording and reproducing a digital signal and a processing apparatus therefor.

[Background of the Invention]

In recent years, devices for recording and reproducing digital signals have been remarkably developed, and there are many devices for recording / reproducing analog / digital conversion (A / D conversion) of analog signals.
In such an apparatus, the influence of a code error (error) which occurs at the time of recording / reproducing is prevented by recording / reproducing by using an error correction code or the like for the digital signal.
However, when transmitting digital signals reproduced by a device that records and reproduces digital signals to other devices, the number of cables in the transmission path, time error between devices or disturbance (instantaneous power failure)
Since a code error occurs due to such reasons, a separate digital signal processing circuit or the like must be provided between the devices in order to prevent the code error (for example, JP-A-57-120213).
The scale of the device increases, which is a problem in terms of economy.

[Object of the Invention]

It is an object of the present invention to provide a digital transmission method and a processing device for the same, which do not impair the reliability of a transmission signal during signal transmission between devices that record and reproduce digital signals.

Example of Invention

An embodiment of the present invention will be described below with reference to FIG. In this embodiment, digital VTRs 10a and 10b are used as a device for recording and reproducing digital signals.

First, the configuration of the digital VTR 10a will be described. The A / D-converted digital signal 3a captured by the input terminal 1a is output to the recording signal processing circuit 12a. The recording signal processing circuit 12a adds an additional signal such as an error correction parity or a synchronization pattern to the digital data 3a from the input end 1a, and outputs it to the magnetic recording / reproducing device 13a. The magnetic recording / reproducing apparatus 13a records the signal 4a output from the recording signal processing circuit 12a on a recording medium such as a magnetic tape, reproduces the signal recorded on the recording medium, and reproduces the reproduced signal 5a on the reproducing signal processing circuit 11a. Output as. The reproduction signal processing circuit 11a detects and corrects an error occurring during recording / reproduction of the magnetic recording / reproducing device 13a based on error correction parity or the like, and outputs the original digital signal 5a at the output end 2a.
Output to. The digital VTR 10a and the digital VTR 10b have the same configuration.

Next, the case of transmitting a digital signal from the digital VTR 10a to the digital VTR 10b, which is the transmission method of the present invention, will be described. Digital VTR10a is the playback side, digital VTR1
0b is the recording side. The digital data 6a detected / corrected by the reproduction signal processing circuit 11a is input to the recording signal processing circuit 12a. The recording signal processing circuit 12a adds to the input digital signal 6a an additional signal such as an error correction parity or a synchronization pattern similar to that output to the magnetic recording / reproducing device 13a, and a recording side reproduction signal processing circuit 11b. Output to. The reproduction signal processing circuit 11b changes from the digital VTR10a to the digital VTR10.
The error generated on the transmission path A during the transmission of b is detected and corrected based on the error correction parity or the like, and is output to the recording signal processing circuit 12b as the original digital signal 7b. Recording signal processing circuit 1
2b is the same as the case of the digital signal 3b from the input end 1b,
The digital signal 7b from the reproduction signal processing circuit 11b is added with an additional signal such as a parity for error correction or a synchronization pattern and output to the magnetic recording / reproducing device 13b. The magnetic recording / reproducing device 13b records the signal 8b output from the recording signal processing circuit 12b on the recording medium. Through the above operation, the signal transmission from the digital VTR 10a to the digital VTR 10b is completed. According to this embodiment, it is possible to effectively prevent an error that occurs during transmission between digital VTRs, and it is possible to significantly improve the reliability of the transmission signal.

FIG. 2 shows a detailed block diagram of the recording signal processing circuit 12a of the recording side VTR 10a.

The recording signal processing circuit 12a includes a switching switch 121, a parity calculation circuit 122, and a synchronization pattern adding circuit 123.
In the switching switch 121, normally the signal 3a from the input end 1a is
During transmission, the digital signal 6a from the reproduction signal processing circuit 11a
Is output to the parity calculation circuit 122. The parity calculation circuit 122 calculates the parity for detecting / correcting an error generated in a magnetic tape or the like and adds it to the original digital signal 6a. Next, in the sync pattern adding circuit 123, identification data (sync pattern) for word synchronization
After adding the magnetic recording / reproducing device 13a or recording side VTR10
Output signal to b.

Next, FIG. 3 shows a detailed block diagram of the reproduction signal processing circuit 11b of the reproduction side VTR 10b. The reproduction signal processing circuit 11a includes a switching switch 111, a synchronization pattern detector 112, and an error correction circuit 11
3. It is composed of a data restoration circuit 114. Switching switch 11
1 is the signal 9b from the magnetic tape 13b and the other playback side VTR 10a
To switch the transmission signal from the sync pattern detection circuit 11
Output signal to 2. The sync pattern detection circuit 112 detects the sync pattern of the reproduction or transmission signal to establish word synchronization, corrects the time base fluctuation of the signal, and outputs the corrected signal to the error correction circuit 113. Next, the error correction circuit 113 detects and corrects an error that occurs during the recording / reproducing process or the transmission. Finally, in the data restoration circuit 114, the original digital signal is restored by removing the synchronization pattern and the parity for error correction, and the output terminal 2b and the recording signal processing circuit 12b.
Output to.

In the present embodiment, when a transmission signal is transmitted, the parity is added as follows and the signal is transmitted. That is, the data after being reproduced from the magnetic tape and subjected to error correction is not directly transmitted as dubbing data, but is once passed through the parity calculation circuit 122 and the synchronization pattern adding circuit 123 of the recording signal processing circuit 12a. This enables transmission as a signal having error correction capability. In such an apparatus, data is usually processed in byte units, and for transmission data, data lines in byte units and clock lines, for example, nine signal lines may be connected, but it is recorded on a magnetic tape. If the signal is transmitted in the same format (serial data of 1 to 2 channels) as the signal to be transmitted, the data has a high speed, but there is an advantage that only a few connecting cables are required between the devices. The data thus added with variability is input to the reproducing circuit of the VTR on the recording side and subjected to synchronization detection, time axis correction and error correction. That is, the reliability of the transmission data can be improved by adjusting the time axis between the dubbing devices and correcting errors due to momentary power failure.

FIG. 4 shows an example of a digital VTR 10a having input / output terminals necessary for implementing the present invention. This device has at least two input terminals 1a, 20 and two output terminals 2a, 30. Reference numeral 12a is a recording signal processing circuit, 13a is a magnetic recording / reproducing device, and 11a is a reproducing signal processing circuit.

Normal digital signals are input to input terminal 1a, while dubbed digital signals with added parity are input terminal 20.
Entered in. A normal digital signal is output from the output terminal 2a, and a dubbing digital signal is output from the output terminal 30.

In addition, although an example of the digital VTR is shown in this embodiment, it goes without saying that it can be applied to general digital equipment such as a digital audio tape and an optical disc.

〔The invention's effect〕

According to the present invention, it is possible to significantly improve the reliability of a transmission signal during signal transmission between devices that record and reproduce digital signals.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram for explaining the recording signal processing means of FIG. 1, and FIG. 3 is a first diagram.
FIG. 4 is a diagram for explaining the reproduction signal processing means in the figure, and FIG. 4 is a diagram showing an embodiment of the present invention.

Front page continuation (72) Inventor Shinzou Doi 1-280 Higashi Koigakubo, Kokubunji, Tokyo Inside the Central Research Laboratory, Hitachi, Ltd. (72) Morito Muta, 1410 Inada, Katsuta, Ibaraki Hitachi Tokai Plant, Hitachi Ltd. (72) Inventor Hiroshi Shiono, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Nikko Video Engineering Co., Ltd. (72) Inventor, Mamoru Kaneko, 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Pref. 72) Inventor Fuyuki Inui 1410 Inada, Katsuta City, Ibaraki Prefecture Inside the Tokai Plant, Hitachi, Ltd. (56) References JP-A-60-15826 (JP, A) JP-A-60-133573 (JP, A)

Claims (2)

[Claims] 1. A recording signal processing means for adding an additional signal to a digital signal, a recording / reproducing means for recording / reproducing an output signal of the recording signal processing means, and detecting and correcting an error contained in a reproduced signal of the recording / reproducing means. In the method of transmitting a digital signal between two or more devices, which includes a reproduction signal processing means for reproducing the original digital signal, the transmitting side device transmits the output of the reproduction signal processing means through the recording signal processing means. Then, in the receiving side device, the transmission signal is received by the recording signal processing means via the reproduction signal processing means. 2. A recording signal processing means for adding an additional signal to a digital signal, a recording / reproducing means for recording / reproducing an output signal of the recording signal processing means, and an error contained in the reproduced signal of the recording / reproducing means is detected and corrected. Then, in the digital signal processing device comprising the reproduction signal processing means for reproducing the original digital signal, the recording signal processing means and the reproduction signal processing means each have two or more input terminals and output terminals, and the input terminals and A digital signal processing apparatus comprising: switching means for switching output terminals, wherein an output terminal of the reproduction signal processing means and an input terminal of the recording signal processing means are connected by the switching means.