JPH0197081A - Device for correcting time base of voice signal - Google Patents

Abstract

PURPOSE:To easily attain correction even in a voice signal where signal detecting time base fluctuation is not included by simultaneously detecting time base fluctuation in control signals which have respectively been recorded in different tracks of a magnetic tape with the voice signal in a magnetic recording reproducing device and correcting time base fluctuation in the voice signal. CONSTITUTION:The reproduced voice signal (a) inputted to a signal input circuit and the control signal (b) recorded in a different track, as well is simultaneously inputted to a control signal input circuit 4. The control signal is inputted to a PLL circuit 5, and a pulse (e) which is synchronized with the control signal and which is M-times is generated. A stable frequency or the signal of a phase being a reference is inputted to a signal generation circuit 7 and it is turned into the clock pulse (d) of M-times frequency. The pulse (d) reads signals stored in a memory 2 through a sequence controller 6. Since the signal (c) is outputted by an output circuit 3, the output signal (c) turns to stable output without fluctuation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a time axis correction device for a reproduced audio signal in a rotary head type magnetic recording/reproducing device, and in particular to a device for correcting the time axis of a reproduced audio signal by a rotary head in the longitudinal direction of a magnetic tape. A magnetic recording and reproducing apparatus that sequentially records and reproduces an audio signal and a control signal indicating the rotational phase of the rotary head as a recording trajectory along the longitudinal direction of the magnetic tape using a fixed head. The present invention relates to a time axis correction device for a reproduced audio signal.

Video and audio signals reproduced by conventional VTRs each contain time axis fluctuation components due to instability in tape running or uneven rotation of a rotary head.

Regarding the conventional video signal time base correction device (TBC),
This will be explained below with reference to the drawings.

FIG. 3 is a simple block diagram of a conventional TBC, and FIG. 4 shows its timing diagram.

In FIG. 3, 1o is a video signal input circuit, and 2
is its memory circuit, and 11 is a signal output circuit.

12 is a burst gate that extracts a burst signal from the video signal, 13 is a PLL circuit, 14 is a sequence controller, and 16 is a signal forming circuit that generates a clock pulse from a reference signal.

In the above configuration, the video signal q including the time axis fluctuation component first enters the input circuit 10, where the burst signal is extracted by the burst gate 12. This burst signal is supplied to the PLL circuit 13, and a pulse j of N times the frequency (for example, three times) is formed in synchronization with this burst signal.

This pulse is transmitted through the sequence controller 14.
It is supplied to the memory circuit 2 (for example, COD) as a clock pulse for writing.

Therefore, even if there is a fluctuation in the signal q on the time axis, the frequency or phase of the clock pulse j changes in response to the fluctuation, and the signal is written to the memory 2.
The intervals between signals written to the memory 2 are constant. Then, a signal with a stable frequency and phase serving as a reference is supplied from the terminal 16 to the signal forming circuit 15, and becomes a clock pulse i of N times the frequency (for example, three times).

This clock pulse i is the sequence controller
14 is used as a clock for reading from the memory 2, and the read signal is outputted by the output circuit 11. Therefore, a signal with no time axis fluctuation is output to the output circuit. -Problems to be Solved by the Invention However, with the above configuration, it is possible to correct the time axis of a signal containing a burst signal or a synchronization signal in a video signal whose time axis fluctuation is to be detected, but it is not possible to correct the time axis of a signal that includes a burst signal or a synchronization signal. However, if the signal does not include a signal for detecting time-axis fluctuation, there is a problem in that it cannot be corrected.

In view of the above problems, the present invention performs time axis correction on an audio signal that does not include a signal for detecting time axis fluctuations.

Means for Solving the Problems In order to solve the above problems, the audio signal time axis correction device of the present invention uses a signal indicating the rotational phase of a rotary head that records a video signal during recording, in the same way as an audio signal. Using a control signal recorded by a fixed head, an audio signal is written in a storage means using a signal phase-synchronized with the reproduction control signal, and is read out from the storage means using a stable reference signal.

Effect of the Invention With the above-described configuration, the present invention detects time axis fluctuations of control signals recorded on separate tracks extending in the longitudinal direction of the magnetic tape at the same time as the audio signal of the magnetic recording/reproducing device, and detects fluctuations due to slippage. , corrects the time-axis fluctuation of the audio signal and supplies a reproduced output of the audio signal without time-axis fluctuation.

Embodiment Hereinafter, a time axis correction device of the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a time axis correction device in one embodiment of the present invention, and FIG. 2 shows its timing system.

In Fig. 1, 1 is an input circuit for a reproduced audio signal, 2 is a signal memory circuit (for example, COD), 3 is a signal output circuit, 4 is an input shaping circuit for a reproduction control signal, 6 is a PLL circuit, and 6 is a sequence The controller 7 is a signal forming circuit for a reference signal.

In the above configuration, the reproduced audio signal a is transmitted to the signal input circuit 1
At the same time, a sale tail control signal recorded on another track is also input to the control signal input circuit 4. The control signal is input to the PLL circuit 6, and a nohalus e is generated in synchronization with the control signal and at M times the frequency (for example, 3 times).

Conopulse e is controlled by the sequence controller 6.
It is supplied as a clock pulse for writing the audio signal a into the memory circuit (for example, C0D) 2.

Therefore, even if there is a time axis variation in the audio signal a, the variation is detected by the control signal detected at the same time,
Corresponding to fluctuations in the control signal, the frequency or phase of the clock pulse e changes and is written to the memory 2 through the sequence controller 6, so the interval between the audio signals a written to the memory 2 is always constant. be.

Then, a signal with a stable frequency or phase serving as a reference is input from the terminal 8 to the signal forming circuit 7, and is combined with a clock pulse d of M times the frequency (for example, 3 times). This clock pulse d passes through the sequence controller 6 and becomes a clock pulse for reading out the signal stored in the memory 2, so that the read signal C is sent to the output circuit 3.
Therefore, the output signal C is a stable output without fluctuation.

Effects of the Invention As described above, according to the present invention, by using the control signal necessary for controlling the rotary head for recording and reproducing video signals, it is possible to correct the time axis fluctuation component of the reproduced audio signal. Even in the case of an audio signal that does not include a periodic signal for detecting time axis fluctuations such as a synchronization signal, the correction can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a time axis correction device according to an embodiment of the present invention, FIG. 2 is a dimming diagram of FIG. 1, FIG. 3 is a block diagram of a conventional time axis correction device, and FIG. FIG. 1.1o...signal input circuit, 2...memory circuit, 3,11...signal output circuit, 4.
...CTL signal input circuit, 5, 13...
PLL circuit, 6, 14... Sequence controller 5r-17, 15... Signal forming circuit, 12.
...Purst gate circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 4

Claims (1)

[Claims] A video signal is sequentially recorded and reproduced by a rotating head as a recording trajectory inclined with respect to the longitudinal direction of the magnetic tape, and an audio signal and a control signal indicating the rotational phase of the rotating head are respectively recorded and reproduced by a fixed head in the longitudinal direction of the magnetic tape. A reproduced audio signal reproduced from a magnetic recording/reproducing device that sequentially records and reproduces a recording trajectory along the same path is sequentially written into a storage means using clock pulses phase-synchronized with a reproduction control signal, and is written sequentially into a storage means using clock pulses phase-synchronized with a stable reference signal. An audio signal time axis correction device, characterized in that the audio signal is read from the storage means.