JPS63296486A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To reduce the disorder of a superimposed signal at the time of special reproduction as much as possible by separating a horizontal synchronizing signal from a playback video signal before a false vertical synchronizing signal is inserted. CONSTITUTION:When the special reproduction is performed, a false vertical synchronous inserting circuit 1 inserts the false vertical synchronizing signal into the playback video signal, a vertical synchronous separating circuit 4 separates the vertical synchronizing signal from the playback video signal into which the false vertical synchronizing signal is inserted, and a horizontal synchronous separating circuit 3 separates the horizontal synchronizing signal from the playback video signal before the false vertical synchronizing signal is inserted to generate a character signal by using the separated vertical and horizontal synchronizing signals, thereby superimposing the character signal on the playback video signal into which the false vertical synchronizing signal is inserted. Consequently, the horizontal synchronizing signal never misses nearby the vertical synchronizing signal and a character signal generating means 5 is supplied with the reference horizontal synchronizing signal at all times, thereby eliminating the disorder of the superimposed signal.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to so-called magnetic recording and reproduction v4, and in particular, to still images,
The present invention relates to a magnetic recording and reproducing device that reduces disturbances in superimposed signals during slow, fast forward and 9 rewind reproductions.

[Prior Art] FIG. 2 is a schematic block diagram of a conventional superimpose circuit. In FIG. 2, a reproduced video signal is applied to a pseudo vertical synchronization insertion circuit 1, and a pseudo vertical synchronization signal is inserted into the reproduced video signal to stabilize vertical synchronization during special playback. The reproduced video signal into which the pseudo vertical synchronization signal has been inserted is applied to a superimpose circuit 2. Further, the reproduced video signal into which the pseudo vertical synchronization signal has been inserted is given to a horizontal synchronization separation circuit 3 and a vertical synchronization separation circuit 4, where the horizontal synchronization signal and vertical synchronization signal are separated, respectively, and a character generation circuit 5
given to. The character generating circuit 5 generates a character signal based on the horizontal synchronizing signal and the vertical synchronizing signal and supplies it to the superimposing circuit 2. The superimpose circuit 2 superimposes the character signal onto the reproduced video signal and outputs the superimposed signal.

FIG. 3 is a waveform diagram of a reproduced video signal. The reproduced video signal given to the pseudo vertical synchronization insertion circuit 1 shown in FIG. 1 is a standard video signal in which the vertical synchronization signal 6 containing equalization pulses is present, as shown in FIG. 3<a>. .

Incidentally, this video signal naturally also includes a horizontal synchronizing signal 7. However, in the output of the pseudo vertical synchronization insertion circuit 1, as shown in FIG. 3(b), since the pseudo vertical synchronization signal 8 is inserted, the horizontal synchronization signal 7 is completely absent during that time.

The purpose of inserting a pseudo vertical synchronization signal in this way is that during special playback, the head traces the magnetic tape at a different angle from the track recorded on the magnetic tape.
This is to prevent vertical synchronization of the television monitor from malfunctioning due to noise that is likely to enter the video signal.

[Problems to be Solved by the Invention] By the way, when the video signal shown in FIG. 3(b) is applied to the horizontal synchronization separation circuit 3, it is obvious that the pseudo vertical synchronization part does not contain a horizontal synchronization signal. Therefore, it is not possible to separate the horizontal synchronization signal.

For this reason, the horizontal synchronization of the character generation circuit 5 is disturbed,
The character signal to be superimposed is disturbed. Most of the character generation circuits 5 transfer character information based on the horizontal synchronization signal, and if the horizontal synchronization signal is not provided, not only the position to be superimposed will be disturbed, but also the content of the character will be disturbed. It also had the disadvantage of affecting the

Therefore, the main object of the present invention is to provide a magnetic recording and reproducing apparatus that separates a horizontal synchronizing signal from a reproduced video signal before inserting a pseudo vertical synchronizing signal in order to reduce the above-mentioned disturbances. .

[Means for Solving the Problem] The present invention inserts a pseudo vertical synchronization signal into a reproduced video signal during special playback, separates the vertical synchronization signal from the reproduction video signal into which this pseudo vertical synchronization signal has been inserted, and reproduces the pseudo vertical synchronization signal. A horizontal synchronization signal is separated from the reproduced video signal before the vertical synchronization signal is inserted, a character signal is generated based on the separated vertical synchronization signal and the horizontal synchronization signal, and the character signal is generated after the insertion of the pseudo vertical synchronization signal. The video signal is configured to be superimposed on the reproduced video signal.

[Function] The magnetic recording/reproducing device according to the present invention separates the horizontal synchronization signal from the reproduced video signal before the pseudo vertical synchronization signal is inserted, so that the horizontal synchronization signal is missing in the vicinity of the vertical synchronization signal. Therefore, a reference horizontal synchronizing signal can always be supplied to the character signal generating means, and superimposition disturbances can be eliminated.

[Example] FIG. 1 is a schematic block diagram of an embodiment of the present invention.

In the embodiment shown in FIG. 1, the reproduced video signal before the pseudo vertical synchronization signal is inserted by the pseudo vertical synchronization insertion circuit 1 is used as the video signal supplied to the horizontal synchronization separation circuit 3. The other configurations are the same as those in FIG. 2 described above.

In this way, since the horizontal synchronization signal is separated from the reproduced video signal before the pseudo vertical synchronization signal is inserted by the horizontal synchronization separation circuit 3, there is no possibility that the horizontal synchronization signal will be lost near the vertical synchronization signal. , character generation circuit 5
Not only can a character signal without disturbances be generated from the above, but also disturbances at the superimposed position can be eliminated.

Note that the input to the vertical synchronization separation circuit is the reproduced video signal after inserting the pseudo vertical synchronization signal in the same manner as in FIG. 2 described above. This is because, as mentioned above, there is a strong possibility that noise will appear on the screen during special playback, and the vertical synchronization separation circuit may malfunction due to the noise signal. If the vertical synchronization separation circuit malfunctions, the vertical position of the superimposed character on the screen will naturally be disturbed. In addition, when noise occurs, the horizontal synchronization signal is also disturbed, but unlike when a pseudo vertical synchronization signal is inserted, the horizontal synchronization signal is not lost for a long time, so it may cause a transfer malfunction in the character generation circuit, etc. The probability of this can also be extremely reduced.

[Effects of the Invention] As described above, according to the present invention, by simply changing the input to the horizontal synchronization separation circuit, it is possible to extremely reduce disturbances in the superimposed signal during special playback while using the conventional configuration. Can be done.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention. FIG. 2 is a block diagram of a conventional superimpose circuit. FIG. 3 is a waveform diagram showing a video signal near vertical synchronization f1@. In the figure, 1 is a pseudo vertical synchronization insertion circuit, 2 is a superimpose circuit, 3 is a horizontal synchronization separation circuit, 4 is a vertical synchronization separation circuit, and 5 is a character generation circuit.

Claims (1)

[Scope of Claims] Pseudo vertical synchronization signal insertion means for inserting a pseudo vertical synchronization signal into a reproduced video signal during still image, slow motion, fast forward, and rewind playback, and generating a character signal based on the horizontal and vertical synchronization signals. A magnetic recording and reproducing apparatus comprising a character signal generating means for generating a character signal, and a superimposing means for superimposing a character signal generated from the character signal generating means on the reproduced video signal, the magnetic recording and reproducing apparatus comprising a horizontal synchronizing signal from the reproduced video signal. horizontal synchronizing signal separating means for separating the vertical synchronizing signal from the output of the pseudo vertical synchronizing signal inserting means and applying it to the character signal generating means; and vertical synchronizing signal separating means for separating the vertical synchronizing signal from the output of the pseudo vertical synchronizing signal inserting means and applying it to the character signal generating means. Equipped with a magnetic recording and reproducing device.