JPH1056617A - Digital signal recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable recording on a tape in the same format for both high-speed recording and standard-speed recording, to shorten time for recording and to expand a utilization range of a digital VTR by performing control so as to execute recording at the extracted speed. SOLUTION: At a synchronization detection circuit 201, the transfer speed of an input signal is extracted from the synchronizing signal of the input signal and a cylinder servo circuit 205 and a capstan servo circuit 206 are controlled so as to provide the same recording format as the case of recording at double speed even when recording is performed at the extracted speed. Then, the input signal, to which a prescribed recording modulation is executed by a recording modulation circuit 204, is recorded onto a controlled medium. The recording modulating processing is performed at n-times speed in conformity with the transfer speed of the input signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal recording / reproducing apparatus, and more particularly, to a use of a digital signal recording / reproducing apparatus by greatly shortening a recording time.

[0002]

2. Description of the Related Art Conventionally, as a digital signal recording / reproducing apparatus (digital VTR), for example, a D2 format VTR has been known. However, with such a conventional VTR, the playback time can be reduced by variable speed playback,
No mention is made of high-speed recording that reduces the recording time to a fraction.

[0003]

The above-described conventional digital VTR is characterized by high image quality and no dubbing deterioration, but no consideration has been given to shortening the dubbing time. For this reason, it takes two hours to record software of, for example, two hours, and there is a disadvantage that inconvenience occurs in usability.

An object of the present invention is to enable high-speed recording to be performed on a tape in the same format as standard-speed recording.
An object of the present invention is to provide a digital signal recording / reproducing apparatus capable of high-speed reproduction and to shorten the recording time, thereby expanding the use range of the digital VTR. For example, it can be used such that two-hour software is recorded in about 10 minutes and reproduced at a standard speed.

[0005]

The above object is achieved as follows. Extracting means for extracting a transfer rate from a digital input signal which has been data-compressed and has been time-axis-compressed to 1 / n and transferred, and controlling the recording means to record at the rate extracted by the extracting means. Is achieved by

[0006]

FIG. 1 is an example of a block diagram of a digital signal recording / reproducing apparatus according to a first embodiment of the present invention, wherein 201 is a synchronization detecting circuit, 204 is a recording / modulating circuit,
205 is a cylinder servo control circuit, 206 is a capstan servo (tape speed) control circuit, 207 is a reproduction reference signal generation circuit, 210 is a demodulation circuit, 211 is a cylinder,
12 is a pair of recording heads, 213 is a pair of reproducing heads,
214 is a capstan for controlling the tape speed, 215 is a recording medium, 216 is a sending reel, and 217 is a take-up reel.

During the recording operation, the cylinder servo circuit 20
5. The capstan servo circuit 206 includes the synchronization detection circuit 2
It operates under the control of the output from 01.

For example, if a signal specified in the MPEG standard is added to a compressed video signal which is an input signal at the time of a recording operation of the present circuit, a synchronization signal indicating a cycle of a picture is added like a picture header. ing. Alternatively, in the digital television signal compressed on the time axis, a signal indicating a picture delimiter such as a vertical synchronization signal is inserted. The synchronization detection circuit 201 extracts the transfer rate of the input signal from these synchronization signals, and makes the cylinder servo circuit 205 and the cylinder servo circuit 205 perform the same recording format even if recording at the extracted speed is performed at 1 × speed. The capstan servo circuit 206 is controlled. For example, for a compressed moving image signal transferred at n times speed, control is performed so that both the cylinder and the capstan operate at n times speed. On the medium controlled in this way, the recording modulation circuit 204 records an input signal that has been subjected to predetermined recording modulation, for example, digital compression, error correction code addition, and recording modulation. These recording modulation processes are also performed at n times speed in accordance with the transfer speed of the input signal. If it is necessary to adjust the frequency or amplitude of the signal after recording modulation according to the recording speed, it is also performed. As a result, the signal input at 1 × speed (normal speed) is
The cylinder, capstan, and recording modulation can be recorded on the medium at n times speed in a format equivalent to a recording format obtained when recording is performed by controlling to operate at 1 times speed (normal speed).

On the other hand, during the reproducing operation, the cylinder servo circuit 205 and the capstan servo circuit 206 operate under the control of the output from the reference signal generating circuit 207.
The reference signal generation circuit 207 outputs a signal to the cylinder servo circuit 205 and the capstan servo circuit 20 at a speed corresponding to the reproduction speed.
6 is controlled. For example, when reproducing at 1 × speed (normal speed), control is performed so that both the cylinder and the capstan operate at 1 × speed (normal speed), and the signal reproduced from the reproducing head 213 is reproduced by the demodulation circuit 210. The demodulation processing is performed at a processing speed and processing content according to the speed, and the reproduced signal is output. As described above, in the present embodiment, since the reference signal generation circuit is built in, even if the input signal is transferred at n times speed, it can be reproduced at an arbitrary speed regardless of the input speed. It is possible. Reference signal generation circuit 20
The speed of 7 is not limited to 1 × speed (normal speed) but may be any speed.

FIG. 2 is a diagram showing the timing of the input / output signals of this embodiment. Reference numeral 251 denotes a compressed image signal as an input signal; 252, a sync signal of 251;
7 is a diagram schematically showing a standard speed reproduction signal which is an output signal, and 256 is a diagram schematically showing a reproduction synchronization signal. As shown in this figure, even when the input signal is input at n times speed, according to the present embodiment, the input transfer speed is detected from the synchronizing signal, and the recording operation is performed according to the speed. It is possible to record at a high speed and to record on a medium in a format equivalent to that of 1 × speed recording. Further, even with the medium recorded in this way, the reproduction speed is controlled by the output of the reference signal generation circuit 207 and can be controlled to an arbitrary speed. It is possible.

[0011]

As described above, according to the present invention,
A digital signal recording / reproducing apparatus capable of high-speed recording and high-speed reproduction can be realized, and the recording time, the data transfer time, and the like can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a digital signal recording / reproducing apparatus according to the present invention.

FIG. 2 is an example of input / output signal timing of the digital signal recording / reproducing apparatus of FIG. 1;

[Explanation of symbols]

 201 synchronization detection circuit 204 recording modulation circuit 205 cylinder servo control circuit 206 capstan servo control circuit 207 reproduction reference signal generation circuit 210 demodulation circuit 211 cylinder 212 recording head 213 ...... Reproduction head 214 ...... Capstan for controlling tape speed 215 ...... Recording medium 216 ...... Sending reel 217 ...... Take-up reel

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keizo Nishimura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (72) Inventor Akira Shibata Corporation, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture

Claims (3)

[Claims] 1. A digital signal recording / reproducing apparatus for recording / reproducing a digital signal which is continuous in time, an extracting means for extracting a transfer speed of an input digital signal, and a recording speed reflecting an extraction result of the extracting means. A digital signal recording / reproducing apparatus characterized by having a recording speed control means for controlling the speed. 2. The recording speed control means according to claim 1, wherein said recording speed control means operates to record the input digital signals having different transfer rates so that the recording format on the medium is the same. Digital signal recording / reproducing device. 3. A digital signal recording / reproducing apparatus for recording / reproducing a digital signal which is continuous in time, a reproduction speed control means for controlling a reproduction speed so as to reproduce at a predetermined transfer speed regardless of a transfer speed of an input digital signal. A digital signal recording / reproducing apparatus characterized by having: