JPH02288566A - Video floppy recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent generation of skew at the upper part of the screen by recording a video signal on two adjacent tracks so that one field of the signal is not consecutive and stopping the pseudo frame reproduction and head changeover at the movement of the head. CONSTITUTION:The device is provided with an odd/even field selection means 20 selecting whether a recorded video signal is a video signal of an odd number field or a video signal of an even number field corresponding to the odd and even track number and a stop period setting means 23 setting the period of stopping head changeover for the reproduction of pseudo frame in response to the field/frame of a reproduction track at present. Then a video signal is recorded on two adjacent tracks so that either of the odd and even number field is not consecutive and when the track is moved during the reproduction, the pseudo frame reproduction and head changeover are stopped for the period set by a stop period setting means 23, and the reproduction of pseudo frame and head changeover are started. Thus, the odd number field and the even number field of the video signal are reproduced alternately at movement for each vertical synchronizing signal and skew at the upper part of the screen is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a video floppy recording and reproducing apparatus that is capable of track movement without causing skew even if the track is moved during playback of a video signal recorded on a video floppy. .

BACKGROUND OF THE INVENTION FIG. 2 shows a block diagram of a conventional video floppy recording and reproducing apparatus. 1 is a recording video signal processing circuit that performs signal processing of a video signal input to a video input terminal; 2;
is the video signal processed by the recorded video signal processing circuit 1.
An FM modulation circuit that performs M modulation, 3 a recording amplifier circuit that amplifies the video signal FM modulated by the FM modulation circuit 2, and 4 a recording gate output circuit that outputs pulses for a period during which the video signal amplified by the recording amplifier circuit 3 is recorded. , 6 is video floppy 16
6, an FM demodulation circuit that demodulates the reproduced FM signal; 7, a reproduced video signal processing circuit that performs signal processing of the FM demodulated reproduced signal; 8; field/frame discrimination [1st path, 9 is field/frame discrimination] which heats the ID signal from the reproduced amplified signal.
When the output of the frame detection circuit 8 is a frame, a head changeover switch switches the magnetic head 16 every vertical synchronization signal, and 1o is a signal delayed by the horizontal synchronization period of the video signal processed by the reproduced video signal processing circuit 7. , and when the output of the field/frame detection circuit 8 is a field, a pseudo frame reproduction circuit switches between a signal delayed by the remaining horizontal synchronization period and the original signal every vertical synchronization signal, and 11 is a recording/reproduction switch for switching between recording and reproduction. A switch 12 is a step motor 13 for moving the magnetic head 16 in the radial direction of the video floppy 15. A step motor drive circuit 14 is a step motor drive circuit for driving the step motor 12.
17 is a spindle motor for rotating the video floppy 16;
18 is a motor control circuit that controls rotation and stopping of the spindle motor, and 19 is a system control circuit that outputs drive commands for the step motor 12 and rotation and stop commands for the spindle motor 17.

The operation of the conventional video floppy recording and reproducing apparatus will be explained below with reference to FIG.

When recording a video signal, switch the recording/playback switch 11 to the recording side, input the recording gate generation signal from the system control circuit 19 to the recording gate output circuit 4,
A recording gate pulse is inputted from the recording gate output circuit to the recording amplifier circuit 3, the recording video processing circuit 1 processes the signal, the FM modulation circuit 2 performs FM modulation, the recording amplifier circuit 3 amplifies the signal, and a recording current is applied to the magnetic head 1e. Record on video floppy 16.

When reproducing the video signal recorded on the video floppy 16, switch the recording/reproduction changeover switch 11 to the reproduction side and use the magnetic head 16 fixed to the head moving mechanism 14 to reproduce the FM signal recorded on the video floppy 16. The picked up FM signal is amplified by the reproduction amplifier circuit 6, the amplified FM signal is demodulated by the FM demodulation circuit 6, and processed by the reproduction video signal processing circuit 7, and the video output terminal is output to the TV monitor. At this time, the FM signal amplified by the reproducing amplifier circuit 6 is input to the field/frame discrimination circuit 8, the ID signal is detected and the field/frame is discriminated, and when the field is discriminated, the output signal of the video signal processing circuit 7 is and a signal delayed by a horizontal synchronization period, the switching of the frame reproducing circuit 1o is switched every one vertical synchronization period,
At the time of frame discrimination, the head changeover switch 9 is switched every vertical synchronization period.

When moving from a frame playback track, the track is moved with the head changeover switch 9 switched every one vertical synchronization period, and when moving from a field playback track, the video signal is processed by the pseudo frame playback circuit 10. Track movement is performed while switching the output signal of the circuit 7 and the signal delayed by 1/2 horizontal synchronization period every vertical synchronization period.

Problems to be Solved by the Invention However, in the above configuration, since the head is moved while pseudo frame playback or head switching is being performed, one vertical synchronization is performed while pseudo frame playback is performed between two adjacent tracks of odd and even fields. If you move one track in a period, if you move to an even field recording track during playback of an odd field recording track, when you play the even field recording track, two consecutive vertical fields will be displayed in the same field as the field that was playing the odd field recording track. Since the same field is played back continuously during the synchronization period, there is a problem in that skew occurs when played back on a TV screen.

The present invention records video signals in two adjacent tracks so that either odd or even fields are not continuous, stops pseudo frame playback and head switching when the head moves, and then plays back the pseudo frame after the movement is completed. Alternatively, the present invention provides a video floppy recording and reproducing apparatus which starts head switching and prevents continuous reproduction of either the number of sounds or the even field of a video signal during two consecutive vertical synchronization periods during trunk movement.

Means for Solving the Problems In order to solve the above-mentioned problems, the video floppy recording and reproducing apparatus of the present invention has a video floppy recording and reproducing apparatus according to the present invention. It has an odd-even field selection means for selecting whether the video signal is a video signal, and a stop period setting means for setting a period for stopping pseudo frame reproduction or head switching according to the field/frame of the currently reproduced track. If either the number of sounds or the even field of the video signal is recorded on a track so that it is not continuous, and the track is moved during playback, the pseudo frame playback and head switching are stopped for the period set by the stop period setting means, and then the pseudo frame This apparatus is provided with means for not continuously reproducing either the odd field or the even field of the video signal during two consecutive vertical synchronization periods after starting reproduction or head switching.

According to the above-described structure, the present invention records odd fields and even fields alternately on the tracks of a video floppy, stops head switching and pseudo frames, moves one track for every vertical synchronization signal, and records vertical fields immediately after the movement is completed. Since a synchronization signal is detected and head switching or pseudo frame reproduction is started, odd and even fields of the video signal are alternately reproduced every vertical synchronization signal during movement, eliminating skew at the top of the screen.

Example Examples of the present invention will be described below.

FIG. 1 shows a block diagram of a first embodiment of the present invention. Components in FIG. 1 with the same numbers as in FIG. 2 are equivalent to the conventional technology, and their explanation will be omitted.

2o is an even field selection circuit that selects whether the input video signal is an odd field or an even field in accordance with the odd or even track number on which the head 1e contacts the video floppy 16, and 21 is a reproduction circuit of the pseudo frame reproduction circuit 1o. A pseudo frame control circuit controls the switching between the signal processed by the video signal processing circuit 7 and the signal delayed by the horizontal synchronization period, 22 is a head switching control means for controlling switching of the head switching switch 9, and 23 is a magnetic circuit. A stop period setting circuit 24 sets the number of vertical synchronization signals during a period during which pseudo frame playback and head switching are stopped when the head 16 moves, and 24 counts the number of vertical synchronization signals after pseudo frame playback and head switching are stopped. This is a vertical synchronization signal counter.

The operation of the embodiment of the present invention will be described below.

When recording a video signal on the video floppy 16, an odd field selected by an odd-even field selection circuit is recorded in an odd track, and an even field is recorded in an even trunk, corresponding to the odd or even track number to be recorded.

When reproducing the video signal recorded on the video floppy 15, the recording/reproduction changeover switch 11 is switched to the reproduction side, and the FM signal recorded on the video floppy 15 is picked up by the magnetic head 16 fixed to the head moving machine groove 14. , the pinked-up FM signal is amplified by a regenerative amplifier circuit 5, the amplified FM signal is demodulated by an FM demodulation circuit 6,
The reproduced video signal processing circuit 7 processes the signal and connects the video output terminal to the TV.
Play on a monitor. At this time, the FM signal amplified by the regenerative amplifier circuit 6 is input to the field/frame discrimination circuit 8, which detects all the 1D signals and discriminates the field/frame.
The pseudo frame reproducing circuit 10, which switches between signals delayed by /2 horizontal synchronization periods, is switched every vertical synchronization period, and when determining frames, the head changeover switch 9 is switched every one vertical synchronization period.

When moving a track, the stop period setting circuit 23 sets the number of vertical synchronization signals during the period during which pseudo frame playback and head switching are stopped according to the field/frame of the track being played back, and the number is set in the system control circuit 19. The value is stored, synchronized with the vertical synchronization signal, the pseudo frame control circuit 21 and head switching control circuit 22 stop pseudo frame playback and head switching, start counting the vertical synchronization signal counter 24, and perform one vertical synchronization. The magnetic head 16 is moved by one track for each signal, and the count value of the vertical synchronization signal counter 24 is synchronized with the vertical synchronization signal that matches the value detected by the stop period setting circuit 23, and according to the field/frame number of the reproduction track. Pseudo frame control circuit 21
Alternatively, the head switching control means 22 starts pseudo frame reproduction or head switching. The setting value of the stop period setting circuit 23 is as follows.

If the track being played back is a field, it will be "2", and if it is a frame, it will be "13".

With the above-described recording system and track movement control system, the odd and even fields of the video signal are alternately switched for each vertical synchronization signal when the track is moved, and the video output terminal is connected to a TV monitor.

During playback, even if the track is moved, no skew occurs on the T1 screen, and the excellent effect of very smooth screen switching is obtained.

Effects of the Invention According to the present invention as described above, even if a track is moved while playing back a video signal recorded on a video floppy, either the odd field or the even field of the video signal is continuous. It is possible to obtain an excellent effect of smooth screen switching without causing skew at the top of the screen by moving the track without making the period the same.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a video floppy recording and reproducing apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. 2o... Odd-even field discrimination circuit, 21...
... Pseudo frame control circuit, 22 ... Head switching control circuit, 23 ... Stop period setting circuit, 2
4... Vertical synchronization signal counter.

Claims (1)

[Claims] a recording means for recording a video signal on a magnetic recording medium having a plurality of concentric tracks; a reproducing means for reproducing the video signal recorded on the magnetic recording medium; a recording/reproducing switching means for switching between recording and reproduction; A magnetic head that contacts two adjacent tracks of a recording medium, a head moving means that moves the magnetic head in the radial direction of the magnetic recording medium, and a field signal recorded on the magnetic recording medium that is divided by 1/2.
pseudo frame reproduction means for switching between a signal delayed by a horizontal synchronization period and a recorded field signal for each vertical synchronization signal; head switching means for switching between two adjacent tracks recorded and reproduced by the magnetic head; and a head switching means for switching between two adjacent tracks recorded and reproduced by the magnetic head. an odd-even field selection means for selecting whether a video signal to be recorded is an odd-field video signal or an even-field video signal in accordance with whether the track number to be recorded is odd or even by contacting the magnetic recording medium; and moving the magnetic head. and a stop period setting means for setting a period during which the pseudo frame reproduction by the pseudo frame reproduction means and the head switching by the head switching means are stopped according to the field/frame of the currently reproduced track, and when the magnetic head is moved. A video floppy recording/playback apparatus characterized in that after stopping pseudo frame playback and head switching for a period set by the stop period setting means, pseudo frame playback or head switching is started.