JPH0221405A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To simplify an operation and to prevent picture quality from being deteriorated due to a mis-operation by providing a mode selection circuit to select the input of an editing mode automatically based on the state of a signal inputted from a video input terminal. CONSTITUTION:In a VTR2 set at a recording state, it is decided whether or not the signal inputted from the video input terminal 5 is the signal reproduced by a VTR1 by the mode selection circuit 3b. A mode switching signal outputted from the mode selection circuit 3b switches the mode of a video signal processing circuit 2b at a recording side, and also, is outputted from a mode switching signal input/output terminal 6b to the outside. Meanwhile, at a reproduction side, mode switching is performed automatically by fetching the mode switching signal from a mode switching signal input/output terminal 6a, and switching the mode of a video signal processing circuit 2a. In such a way, it is possible to perform dubbing with the optimum mode, and also, to prevent the picture quality from being deteriorated due to the mis-operation of a change- over switch.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic recording and reproducing apparatus that automatically turns on and off one editing mode.

(Prior Art) In recent years, as the price of VTRs has decreased, the number of households with multiple VTRs has rapidly increased, and as a result, opportunities for dubbing between VTRs have increased. On the other hand, on the VTR side,
Equipped with a rotating erasing head that allows for clean splicing, and in order to reduce image quality deterioration during dubbing, many video signal processing circuits are equipped with an editing mode. Although the S/N ratio is improved by changing the frequency characteristics of the level signal components, in the case of dubbing, etc., these processes have an adverse effect on the contrary, resulting in poor waveform reproducibility.

Therefore, in the 1 editing mode, since the amount of change in frequency characteristics is modest and the waveform reproducibility is improved, by using it during dubbing, it is possible to reduce image quality deterioration due to dubbing.

FIG. 4 shows a conceptual diagram of dubbing using a conventional magnetic recording/reproducing device. In FIG. 4, 20 is a VT
R1, 21 are VTR2, la, lb are video heads, 2
Reference numerals a and 2b are video signal processing circuits, 4 is a video output terminal, 5 is a video input terminal, and 9a and 9b are mode changeover switches. As shown in Figure 4.

The video signal processing circuits 2a and 2b have 5 normal modes and an editing mode, and when dubbing, the editing mode is selected using mode changeover switches 9a and 9b provided on the operation panel of each VTR. It will be done.

(Problem to be Solved by the Invention) However, with the above configuration, when dubbing, it is necessary to change the mode selection switch of each VTR one by one, and many users switch the editing mode without knowing how to use it. However, dubbing is performed without using the editing mode, the editing mode is not utilized, and conversely, erroneous operation of the changeover switch can lead to deterioration of the S/N ratio during normal playback.

(Means for Solving Problem 3111) In order to solve the above problems, the magnetic recording/reproducing device of the present invention automatically selects whether to turn on or off the editing mode depending on the state of the signal input from the video input terminal. The configuration includes a mode selection circuit.

(Function) As described above, the present invention includes a mode selection circuit that automatically selects a mode depending on the state of an input signal during recording, so that when dubbing, the mode switching of the VTR on the recording side is automatically performed. , further transmits the mode switching signal obtained from the mode selection circuit on the recording side to the VTR on the playback side,
By also switching the mode on the playback side, the mode switching on the playback side also becomes automatic. Therefore, you can dub in the optimal mode without having to worry about switching modes, and
This makes it possible to eliminate image quality deterioration due to erroneous operation of the changeover switch.

(Example) Examples will be described below with reference to the drawings.

FIG. 1 shows a conceptual diagram when dubbing is performed using a magnetic recording/reproducing apparatus according to an embodiment of the present invention;
0 is a VTRL, 21 is a VTR2, 3a and 3b are mode selection circuits, and 6a and 6b are input/output terminals for mode switching No. 43.

In the VTR 2 in the recording state, the mode selection circuit 3b determines whether the signal input from the video driver 15 is a signal reproduced by the VTRI. The mode switching signal outputted from the mode selection circuit 3b switches the mode of the video signal processing circuit 2b on the recording side, and is outputted to the outside from the mode switching signal input/output terminal 6b. On the other hand, on the playback side, by taking in a mode switching signal from the mode switching signal input/output terminal 6a and switching the mode of the video signal processing circuit 2a, mode switching can be made automatic.

FIG. 2 is a block diagram showing one embodiment of the mode switching circuit. In Figure 2, 11 is HP F, 1
2 is a detection circuit, and 13 is a voltage comparison circuit.

Since the VTR playback signal has a narrow band, the HPFII extracts the signal outside the VTR band, and when there are very few signal components, it can be determined that the mode is for editing. Therefore, HP
A detection circuit 12 detects the F passing signal, and a voltage comparison circuit 13 compares whether the detected output voltage is higher than a specified voltage.
If the voltage is below a specified voltage, a mode switching signal is output to switch to editing mode.

FIG. 3 is a block diagram of another embodiment of the mode selection circuit.6 In FIG. 3, 14 is a synchronizing signal separation circuit, 15 is a phase comparator circuit, and 16 is a vCO 117 is a synchronizing signal generating circuit. Since the VTR playback signal has a lot of jitter, the synchronization signal generated by the synchronization signal generation circuit 17 and the synchronization signal separated by the synchronization signal separation circuit 14 are separated by the phase comparator circuit 15.
Jitter is detected by comparing the two, and when there is a large amount of jitter, a mode switching signal is output to switch to the editing mode. Although a synchronizing signal is used in FIG. 3, similar switching detection is possible using a burst (i) signal.

(Effects of the Invention) As described in -1- below, the magnetic recording and reproducing apparatus of the present invention includes a mode selection circuit that selects whether to turn on or off the editing mode depending on the state of the signal input from the video input terminal. As a result, mode switching becomes automatic, and it is possible to simplify the operation, and also to eliminate deterioration of image quality due to erroneous operation, which is an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of dubbing using a magnetic recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram of an embodiment of a mode selection circuit, and FIG. 3 is a mode selection circuit. FIG. 4, a block diagram of another embodiment of the circuit, is a conceptual diagram when dubbing is performed using a conventional magnetic recording/reproducing device. la, lb... video head, 2a, 2b...
Video signal processing circuit, 3a, 3b...Mode selection circuit, 4...Eirin output terminal, 5...Video input terminal, 6a, 6b...Mode switching signal input/output terminal, 2
0...VTRI, 21...VTR2゜Patent applicant Matsushita Electric Industrial Co., Ltd. Go to the statue

Claims (1)

[Claims] In a magnetic recording and reproducing device that has an editing mode other than the normal mode as the operation mode of the video signal processing circuit, mode selection that automatically selects whether to enter or turn off the editing mode depending on the state of the signal input from the video input terminal. A magnetic recording/reproducing device characterized by comprising a circuit.