JPS6161580A - Video signal reproducing device - Google Patents

Abstract

PURPOSE:To compensate most suitably a drop-out by selecting the picture quality of a reproduction picture in accordance with the type and purpose of recorded picture information when the drop-out occurs. CONSTITUTION:When the 1st and 2nd field signals recorded in the 1st and 2nd tracks 2 and 3 of a recording medium 1 are alternately outputted at every field by pickups 4 and 5 corresponding to the tracks, a reproduction field signal at the non-output side is delayed by the field signal at the output side. When a drop-out is detected in the field signal at the output side, the signal with the drop-out part is replaced with the reproduction field signal at the non-output side so as to output it.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a video signal reproducing device, and more particularly to a signal processing circuit suitable for dropout compensation in a device that repeatedly reproduces still images.

[Background of the Invention] As a device for recording and reproducing video signals such as television signals, video tape recorders (hereinafter referred to as vT recording media (video tapes in the case of VTR) are used to record and reproduce signals that are missing due to dust, dirt, etc. that adhere to the recording medium (VTR). A circuit for compensating for dropouts is provided.Specifically, as shown in Japanese Patent Publication No. 39-19289, the signal delay of one horizontal scanning period is utilized by using the correlation between signals of adjacent row signal periods of the television signal. The dropout is compensated for by replacing the original signal with the original signal.Even a long dropout that lasts for more than one horizontal scanning period (hereinafter referred to as 1H) can be compensated for if the 1H delay circuit is used as a feedper. Therefore, noise on the monitor will not disturb the synchronization signal and cause the screen to become distorted.

However, depending on the ia of the image to be reproduced and the purpose of use, performing dropout compensation does not necessarily result in an increase in the information obtained.

On the contrary, it becomes false information and may even cause damage. For example, X Jil CT (Computer T
omo-grahy) is recorded on an electronic still camera and then played back, even if noise occurs on the monitor, that part is determined to be noise and the other parts are used for diagnosis. However, even if the noise part is compensated for dropout and the diagnosis is performed using a different image from the actual image, accurate diagnosis can be made.

Furthermore, in a still image signal reproducing device such as an electronic still camera, since the same sequence is repeatedly reproduced, the degree of dropout occurrence becomes high.

Therefore, it is better to perform dropout compensation.
Depending on the type of image or intended use, a dropout compensation circuit with higher performance than conventional dropout compensation is required.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a video signal reproducing device that can select the image quality of a reproduced image depending on the type of recorded image information and the purpose of use when a dropout occurs in the video signal reproducing device. The objective is to provide an optimal dropout compensation circuit.

[Summary of the invention]

In order to achieve the above object, the present invention provides that, when the dropout detection means detects a dropout, the alarm means issues an operator VC1iliF alarm, and the operator performs the following steps: 1; performs dropout compensation.

2; Stop dropout compensation.

The present invention is characterized in that it is possible to obtain a reproduced image according to the type m of the image information and the purpose of use by selecting one from among them and selecting whether or not to insert a specific signal into the dropout portion.

Furthermore, as a dropout compensation circuit, two field signals with the same horizontal synchronization time No. 48 are prepared, and high-quality dropout compensation is performed using the field correlation of the still image of the frame signal. Dropout compensation using line correlation is also used to ensure reliable compensation. Furthermore, a delay circuit is also used to obtain the two interphase signals, thereby making it possible to downsize the circuit.

Specifically, the first . The 11th and 2nd field signals recorded on the second track and the respective tracks,
This is a still image signal reproducing device that can reproduce frame images by outputting one field signal alternately for each field. The signal is delayed with the field signal on the output side, and when dropout is detected in the field signal on the output side, the signal in the dropout portion is replaced with the reproduced field signal on the non-output side and output.

[Embodiments of the invention]

A first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In this embodiment, information recorded on the recording tracks 2 and 3 of the recording medium 1 is reproduced.

A reproduction amplifier 6.7 amplifies the signals reproduced by the reproduction pickups 4 and 5, respectively, and the outputs of the reproduction amplifiers 6 and 7 (switching that outputs the i number by switching it every field). Switch f 8a, 8b and selector switch 8
a switching signal generation circuit 9 that supplies switching signals to a and 8b;
A dropout detection circuit 10 detects a dropout from the output signal of the switching switch y'''8a, and when the dropout detection circuit 10 detects a dropout, the vf
A display circuit 11 that displays a warning, a dropout compensation circuit 12 that performs dropout compensation when a dropout is detected by the dropout detection circuit 10, a demodulation circuit 13, and a signal processing circuit that performs signal processing such as bias It consists of a processing circuit 14 and a signal insertion circuit 15 that inserts a signal of a specific voltage into the signal after dropout compensation.

Furthermore, the dropout compensation circuit 12 includes a selection switch f-23 for selecting whether or not to perform dropout compensation;
'Al- which delays the output signal of the changeover switch 8b by %H.
1. When the delay circuit 24 and the selection switch 23 are closed, the switch 25 outputs one of the output of the switching switch f8a and the output signal of the delay circuit 24 according to the output signal of the dropout detection circuit 10. Become. Shang Sui, f
"25 is set to output the output signal of the switch yf8a when the dropout detection circuit 10 does not detect a dropout.

The signal insertion circuit 15 includes a synchronization separation circuit 16 that reproduces a synchronization signal from the output signal of the signal processing circuit 14, and a blank signal that has the same pulse width T3 as the blanking pulse and excludes the synchronization signal portion from this synchronization signal. A blank signal generation circuit 17, a clamp circuit 18 that clamps the output No. 3 of the signal processing @ line 14, a voltage source 19 that generates No. 15 to be inserted into the dropout part, and the output signal of the dropout detection circuit 10 and the blank. Insertion is determined by an AND circuit 20 which calculates the logical product of the output signals of the signal generation circuit 17, a selection switch . When the switch f- is closed, the output signal of the clamp circuit 18 and the voltage source 19 are determined based on the output signal of the AND circuit 20.
It consists of a switch that switches and outputs the output signal of %22.

Here, since the dropout detection signal does not include a synchronization signal, the synchronization separation circuit 16, blank signal generation circuit 17, and AND circuit 20
This is used to prevent synchronization signals from being lost by not inserting signals from the

The operation will be explained below. Recording medium 1 for recording signals
As such, a magnetic sheet is used here. The reproduction pickups 4 and 5 are elements for reproducing information recorded on the recording medium 1, and are shown here as magnetic elements. Recording medium 1 is rotated at a constant speed, recording track 2
．． For example, a video tape recorder (hereinafter referred to as VTR) produces a video signal of one field per rotation in each of the six rotations.
M modulated and recorded concentrically. A frame signal of the video signal, for example, a first field signal, is recorded on the recording track 2 over one round, and the next second field signal is continuously recorded on the recording track 3. Therefore, the two tracks are alternately combed every field, and n! If it does, the still image frame signal will be played back. The signals reproduced by reproduction pickups 4 and 5 are amplified by reproduction amplifiers 6 and 7, respectively, and switches 8a and 8
At b, this signal is alternately switched for each field to become a frame signal.

The switching operations of the switches 3a, 8b are controlled by a switching signal supplied from the switching signal generation port 19. Switches 8a and 8b can be used, for example, when switch yf8a is connected to playback amplifier 6.
When the signal from the playback amplifier 7 is being output, the switch yf8b outputs the signal from the reproduction amplifier 7, and information from opposite tracks is output. switch 8a
The output of is Sui.

f-25 and also to the dropout detection circuit 10. Normally, the switch 13 is
This signal is demodulated into an FM signal by the next demodulation circuit 13, and then sent to the reproduction processing circuit 1.
4, the signal undergoes processing such as de-emphasis and is output as a reproduced video signal. The output of switch f-8b is delayed by a predetermined time in the delay circuit 24 and input to switch P25. A dropout detection circuit 10 detects so-called dropout, which is a recording drop, from the output signal of the switch y-8a and generates a dropout detection signal. When a dropout is detected, the display circuit 11 displays a dropout to the operator.

Report the occurrence of a disaster. The operator selects whether or not to perform dropout compensation depending on the type of daily report recorded on the storage medium 1. If it is determined to perform dropout prevention, the selection switch 23 is closed and a dropout detection signal is supplied from the dropout detection circuit 10 to the f25 IC. The selection switch 23 is
It goes without saying that the selection may be made in advance before receiving an alert on the display circuit 11, for example, at the start of the operation.

The dropout detection-If signal supplied to the switch ye2s is the 1 signal from the delay circuit 24 when a dropout occurs.
This is a signal that outputs a death sign, and dropouts are compensated for. The delay circuit 14 is a circuit for synchronizing the times of two signals switched by the switch F-15. As in this embodiment, <TW1 field makes one revolution, and two fields of signals are continuously transmitted to two tracks, one field at a time. , the delay time of the delay circuit 14 becomes H (H is horizontal scanning time) as described later.

Incidentally, in FIG. 1, the configuration is such that one field of signals is recorded in one rotation of the recording medium. The reason for this is
This is to take advantage of the features of the so-called electronic still camera, which has been recently proposed as a still image recording and reproducing device, and which integrates a video camera using an integrated image sensor and a magnetic recording device.

This device, which uses a recording medium such as a magnetic sheet in place of the usual salt protection film, has the advantage that it does not require development, so it can be played back instantly, and the magnetic sheet can be erased and reused. has. For scenes with movement, a shutter is used to capture the image, and by recording the field image on a medium and replaying it repeatedly, a still image without blur can be displayed on a monitor such as a television. In such usage, it is convenient to be able to record one f-field signal once per revolution of the recording medium.

However, as a matter of course, a field image has only half the number of scanning lines as a frame image, so the image quality deteriorates. Therefore, it is preferable to record frame images to deal with the effects of stationary objects without movement. It is preferable to record and reproduce images.

The operation of the dropout compensation circuit 12 will be explained in detail using the waveform diagram of FIG. A and B are diagrams showing the relationship between the recording track 2 and the synchronization signal of the video signal recorded on the recording track 5. 42 indicates a horizontal synchronizing signal, and C and 2 indicate a vertical synchronizing signal. Recording tracker 2 contains one field (262, 5) from recording start time T1 to T2.
H) signal is recorded over one round, recording track 3
, the next field (26
2,5H) signals are recorded. Since the recording medium rotates once in the time of one field, times T1 and T2. Time T
2 and Ts are at the same location on the recording track), the recording track 2 is reproduced, the pickup 4 is used to reproduce the recording track 3, and the recording track 3 is repeatedly reproduced by the reproduction pickup 5, and this signal is alternately transmitted every field. If you switch it off, a still image of the frame will be played. Normally, each track is provided with a dedicated head, and recording and playback are performed using two tracks, so the vertical synchronization signals between the two tracks of the playback signal coincide in time, but the horizontal synchronization signal is +H. This causes a time lag. (Fig. 2 A, B) Fig. 2 C shows the reproduced signal waveform from recording track RI 2, E shows the reproduced signal waveform from recording track RI 3, and C shows the part corresponding to the horizontal synchronizing signal. Indicated by vertical lines. (4 in the diagram
In the embodiment shown in FIG. 1, two field Q signals constituting a frame are simultaneously reproduced by dedicated reproduction pickups.

Therefore, unlike in a home VTR, the reproduced signals do not alternate intermittently, but signals are always reproduced from the two channels as shown in FIG. 2C and D.

Assuming that the signal is supplied to the demodulation circuit 13 via the switch 8a and the switch 8a and the switch f-25, the reproduction signal from the reproduction amplifier 7 [D in FIG. The waveform shown in Figure 2 CK contains a dropout. This signal is fed to a dropout detection circuit 10 where the dropout is detected and Dropout period ″r,? The dropout pulse corresponding to f2 is
5.

The pulse is generated and the jEA 16 is connected to 5 to output the @ signal from the delay circuit 24.

The input waveform of the delay circuit 240 is shown in FIG. 2E, and after being delayed for a certain period of time, the waveform shown in FIG. 2F is output. Since the waveform shown in the dropout period F is outputted from the switch 25, the dropout is replaced with the reproduced signal from the Ikegata track and the signal loss is compensated for. # As mentioned above, since the time difference between the two transistors is +H, the delay circuit 14 may use a +H delay line. When recording still images of frames with no movement, the correlation between two fields is extremely strong, so even if dropouts occur, it is possible to obtain high-quality reproduced images that are almost the same as the original images. In particular, when a longer dropout of several H occurs, the method using field correlation of the present invention is extremely effective compared to the conventional dropout and dropout compensation using line correlation.

The dropout-compensated signal is reproduced by a demodulation circuit 13 and a signal processing circuit 14 to become a video signal.

Next, the operation of the signal insertion circuit 15 will be explained.

This circuit inserts a specific signal, such as a black level signal, into one dropout part when a dropout occurs, so that the dropout part can be clearly distinguished from other normal parts on the screen, and the dropout part can be clearly distinguished from other normal parts. This is a circuit that allows various judgments to be made using only certain parts. When the operator is alerted to the occurrence of a dropout on the display circuit, select the dropout switch.

By selecting #21, it is possible to freely switch between the #J image for which dropout compensation has been performed and the signal in which a specific number 1 is inserted in the dropout portion.

The following description will be made assuming that signal insertion is selected on the selection line 7-21 and the switch 21 is closed.

The dropout compensated output signal on line y-25 is provided to clamp circuit 18 and sync separation circuit 16. The clamp circuit 18 is a circuit that fixes the synchronous peak or pedestal of the video signal to a constant DC voltage. The line f-22 is an output switch that switches between the signal of the clamp circuit 18 and the output of the voltage source 19.
The output signal of 1DII is output. The output of switch f22 is connected to output terminal 5°. The synchronization separation circuit 34 is a circuit that separates the synchronization signal from the video signal.The next stage plank signal generation circuit 34 generates a pulse corresponding to the blanking portion of the video signal and outputs it to the AND circuit 20. The AND circuit 2o performs a logical product of this blanking pulse and the dropout pulse output from the dropout detection circuit 1o, and controls the switch 22 with this output signal.

FIG. 3 shows waveforms of each part of the signal insertion circuit 13.

Figure 3 shows the output of f″8a and the 1d waveform.
In the figure, π is the output signal waveform of the doro and gaudo detection circuit 10,
In the figure, ■ is the output signal waveform of the signal processing circuit 14, y in the figure is the output waveform of the synchronous separation circuit 16, V is the output waveform of the blank signal generation circuit 17, ■ is the output waveform of the AND circuit 20, The same diagram shows the switch appearing on the output terminal 50, f-22
This is the output waveform of

In other words, the waveform shown in FIG. 3N is a waveform obtained by extracting only the synchronizing signal from the video signal shown in FIG.
a; This is the waveform obtained from the Ts pulse. When the logical product of π and the waveform shown in V is taken, the waveform shown in ■ is obtained. That is, this signal has a waveform obtained by removing the blanking pulse from the dropout 1 pulse. (Time T2~T
y, T-T! , Ts~Tp)('J) waveform signal is supplied to P22, and when the waveform (■) is 10-"0, SW, , +22 outputs the signal from the frang circuit 18, and is inverted. When the voltage source 520′ is set to the black level of the video signal, the output waveform of y″31 becomes (J). In other words, the dropout portion is replaced with information that is completely different from the original information (black level in the figure).

Not replacing the synchronization signal part is necessary to prevent synchronization from being disrupted on the monitor. Further, in FIG. 3, the dropout portion is replaced with a black level, but since it is sufficient to be able to determine dropout, it may be replaced with a white level, and the voltage source 32 may be made variable.

As described above, in the signal insertion circuit of this embodiment, the dropout portion becomes a signal completely different from the original information on the reproduction monitor, so that the dropout portion can be easily identified. Also, Sui in Figure 1.

By turning f-21 on and off, you can correctly recognize the dropout section.

As the display circuit of this embodiment, a display using a lamp or the like or a video signal (enlarging characters and displaying dropouts) can be considered.

Next, a second embodiment of the present invention will be explained using FIGS. 4 and 5. Normally, the probability that a dropout will occur on two buttons at the same time is extremely small, but this embodiment ensures dropout compensation even in such a case.

In this embodiment, the dropout compensation circuit 12 in the first embodiment is changed to a pond configuration, and the other configurations are the same as in the first embodiment. Therefore, only the configuration of dropout compensation circuit 12 will be described.

The dropout compensation circuit 12 of this embodiment includes a delay circuit 24 that delays the output signal of the changeover switch 8b by ÷H, a drop/gaud detection circuit 26 that detects a dropout in the output signal of the delay circuit 24, and a dropout detection circuit 26 that detects a dropout in the output signal of the delay circuit 24. A mutually interlocked selection switch yP2sa selects whether or not to perform dropout compensation when the detection circuit 10 detects dropout.

23b, and a switch y- for selecting and outputting the output signal of the switch 8a and the output signal of the delay circuit 24 when a dropout is detected in the dropout detection circuit 10.
29, the AND circuit 28, the delay circuit 27 for IH delaying the output signal to the demodulation port @13, and the AND circuit 28, when the dropout detection circuit 10 and the dropout detection circuit 26 both detect a dropout. %50, which outputs the output signal to the demodulation circuit 13.

Also in this embodiment, when performing dropout compensation, the selection switch y-P25a is linked to the VC.

25b is closed.

The operation of Doro and Guact compensation will be explained below. The output of the delay circuit 24 is supplied to the changeover switch y-29, and also to the mud/gaud detection circuit 26. The outputs of the two doro and gaudo detection circuits 10 and 26 are inputted to the AND circuit 28, and the output of the KAND circuit 28 is supplied to the switching ray 1f-5011C.

The changeover switch f-3011C is supplied with the output of the changeover switch 22 and the output of the delay circuit 27, and converts these two signals into A.
The selection is made according to the signal from the ND circuit 28.

The output of the switch f-50 is supplied to the demodulation circuit 13, the delay circuit 13, and the delay circuit 27VC. The dropout detection circuit 26 operates in the same way as the dropout detection circuit 1o, except that it detects dropout of the output signal of the delay circuit 24.

The AND circuit 28 is a two-dot circuit.

When the output signals of the dropout detection circuit 10.26 are ANDed, and both are high (indicating dropout in this case),
The switch P30 generates a signal that outputs the signal from the delay circuit 27. Changeover switch 30. Delay circuit 2
7. The dropout detection circuit 10.26 and the AND circuit 28 constitute a second dropout compensation circuit, which compensates for dropouts that cannot be compensated for by -M in the previous stage.

FIG. 5 shows the waveforms of each part in FIG. 4, and the operation will be explained.

In the same figure, H shows the output waveform of F-8a), E and H show that dropouts have occurred. ■ is the output waveform of the dropout detection circuit 10 that detected the dropout of this signal.
In the output waveform C1K, the output signal changeover switch 29 of the delay circuit 24 outputs the signal of the delay circuit 24, resulting in a waveform shown by M, but it is dropped out.

Please keep busy during the period of i! ! Since the output K of the extension circuit 24 includes dropouts, the dropouts are not completely compensated for and dropouts remain. L is the output waveform of the dropout detection circuit 26 to which the output of the delay circuit 24 is supplied 17, and the output signals of the two dropout detection circuits 10 and 26 indicated by I and L are AN
Since the signal is input to the D circuit 28, the output of the AND circuit 28 has a waveform indicated by N. By taking the AND of the waveforms of (2) and (L), when both of them are 1 high and 4, a "I" is output.

In other words, when dross and guact occur in the two input drum shapes of the switching switch and %29 (in the waveform of M, it is round),
A pulse indicating the force is emitted.

0 is the output waveform of the delay circuit 27, and the changeover switch 30
The output signal of is delayed by 11-1. The reason why the signal is delayed by 1H here is to replace it with the IH# signal at the time of drop, drop, etc. During the doro and gact periods Wa and Ga, the output of the delay circuit 27 is 1 without dropout as shown in O.
A signal H# is prepared, and by replacing it with the signal m, a signal whose dropout has been completely compensated for is output from the changeover switch 30 as shown at P.

As mentioned above, if there is a dropout on one of the two tracks, it is possible to perform high-quality dropout compensation using field correlation. Even in this case, complete dropout compensation using line correlation by the slow i circuit 27 is possible.

FIG. 6 shows a third embodiment of the present invention (similar to the second embodiment, it shows a modification of the dropout compensation circuit 12), which shortens the total delay time of the delay line used, and The present invention provides a dropout compensation circuit having a configuration that allows the circuit to be miniaturized. The embodiment shown in FIG. 3 has a configuration having two delay circuits of +H and 1H, but the dropout compensation circuit of this embodiment is composed of two +H delay circuits.

However, the dropout compensation circuit of this embodiment is composed of two +H delay circuits.

The difference from the embodiment shown in FIG. The output of the delay circuit 32 is connected to the switching switch 31, the input of the dropout detection circuit 26 is connected to the output of the switching switch 1f8b, and the output of the nuclear dropout detection circuit 26 is connected to the switching switch 1f8b. It's because it's connected to IC to control 31.

The delay times of delay circuits 24 and 32 are both +H. The changeover switch 29 switches the delay circuit 2 when a pulse indicating the occurrence of a dropout is input from the dropout detection circuit 10.
J) Connected to output the signal from 4. Switch switch;
y-sl is activated by the delay circuit 32 when a pulse indicating the occurrence of a dropout is input from the dropout detection circuit 26.
connected to output signals from the Changeover switch 8
b from the output of selector switch 31. The field phase switch 29 shown in FIGS. 1 and 4 switches the output of the delay circuit 24 and the output of the switching switch 8a according to the signal of the dropout detection circuit 10. This is a dropout compensation method using Switch switch, y-29
From the output of delay circuit 32. The input path to the changeover switch 29 via the changeover switch 31 and the delay circuit 24 is a dropout compensation method using line correlation. By using the delay circuit 24 for both methods, the delay time of the delay circuit 32 used for the latter method can be set to +H.

A selector switch 29°3 is placed between the two delay circuits 52 and 24.
1, and the signal from the delay circuit and the playback signal from the recording track (switch switch) are configured to switch the outputs of %sa and sb, respectively, in order to maintain the continuity of the synchronization signal correctly. .

The operation will be explained below using waveform diagrams of OFF diagrams. Q is the output waveform of the changeover switch yf8a, LL is the output waveform of the changeover switch y''8b, S and T are the output drum shapes of the dropout detection circuit 10 and the dropout detection circuit 26.U, V, and W are In each delay circuit 24°Q,
Dropouts yo and da occur, dropouts re and zo occur in R, and dropouts balsutsu, ne, and kuu shown in S and T are obtained. The changeover switch 29 switches the signals indicated by Q and U, but since U is a signal obtained by delaying R by +H or delaying Q by 1H, the times of the horizontal synchronizing signals of Q and U coincide. (Q and 几 are shifted by +H) Similarly,
The changeover switch 31 switches the signals indicated by 几 and V, but since V is a signal obtained by delaying Q by +H or by delaying 几 by 1H, the times of the horizontal synchronizing signals of 几 and V coincide. Therefore, the horizontal synchronizing signal does not shift due to the switching operation of the changeover switches 29 and 31, and no skew occurs.

When dropout occurs, the selector switch 29
Since the Q signal is replaced with the U signal, dropout is compensated as shown at W. When a dropout occurs, the switch switch Y-31 replaces the normal signal with the V signal, but since no dropout or guact has occurred in the Q signal during this period, W is a waveform in which Q is output as is. becomes. When a dropout occurs, the changeover switch f- is turned on at time T5.
31 is connected to output V, and this connection is maintained until Ts when dropout ends. Since U is a signal delayed by +H for the selector switch 31, the time T5
This is a waveform in which V is output from a time delayed by +H from time T8 to a time delayed by +H. When a dropout occurs at time T6, the switch P29 is connected to output the U signal, and this connection is maintained until time T7 when the dropout ends. At time T6, a dropout occurs as shown in the diagram, but as described above, a signal obtained by delaying V by +H without dropout is prepared at U as described above. Therefore, from time T6 to time T7, switching switch f-29-delay circuit 32-switching switch °2te31
The dropout is compensated for by repeatedly outputting the signal from 1H before in the loop of the delay circuit 24 and the changeover switch 29, as shown by W.

According to this embodiment, since the delay time of the two delay circuits is only +H, there is an effect that the circuit can be miniaturized.

The first point explained above. Second. In the third embodiment, the delay circuit is connected to the demodulation circuit 13. Although the configuration is such that it is placed before the signal processing circuit 14, the same effect can be obtained even if it is placed after the signal processing circuit 14.

Furthermore, although an example of application to a magnetic recording/reproducing device has been described, the present invention can also be used in other devices.

〔Effect of the invention〕

As described above, according to the present invention, the operator looks at the admiration display of the dropout, and depending on the type and purpose of the image being played back,
It is possible to select whether or not to perform dropout compensation and whether or not to reliably display the dropout portion, improving the reliability of reproduced images.

Furthermore, in the dropout compensation circuit used in the present invention, 2
It makes effective use of the frame image playback feature that reproduces frame images from field images recorded on the 8
A high degree of dropout compensation can be performed.

[Brief explanation of the drawing]

FIGS. 1, 4, and 6 respectively show the first embodiment of the present invention. Second
．． The configuration block diagram, FIG. 2, FIG. 5, and off-line diagram showing the third embodiment are A.1. FIG. 3 is a waveform diagram illustrating dropout compensation in the fifth embodiment. FIG. 3 is a waveform diagram illustrating the operation of the signal insertion circuit in the present invention. 1... Recording medium, 2, 3... Recording track, 4, 5
...Reproduction big up, 6.7...Reproduction amplifier, 8
a, 8b...switch switch, ? , 9... Switching signal generation circuit, 10... Dropout detection circuit, 11... Display circuit, 12... Dropout compensation circuit, 13...
- Demodulation circuit, 14... Signal processing circuit, 15... Signal insertion circuit, 16... Synchronization separation circuit, 16... Synchronization separation circuit, 17... Blank signal generation circuit, 18...
Clamp circuit, 24, 27.52...Delay circuit, 2
6...Dropout detection circuit. Part 2 Mistake 3 Diagram

Claims (1)

[Claims] 1. A reproduction means for reproducing a video signal recorded on a recording medium, a signal processing circuit for reproducing a video signal from a signal reproduced by the reproduction means, and a signal processing circuit for reproducing a video signal from a signal reproduced by the reproduction means; dropout detection means for detecting a dropout of a signal; dropout compensation means for performing dropout compensation according to an output signal of the dropout detection means; and a warning when a dropout is detected by the dropout detection means. 1. A video signal reproducing device comprising: warning means for emitting a warning. 2. The video signal reproducing device according to claim 1, wherein the dropout compensating means includes a dropout compensating circuit and a changeover switch for switching between operating and stopping the dropout compensating circuit. 3. A video signal reproducing apparatus according to claims 1 and 2, wherein the warning means includes signal insertion means for inserting a predetermined signal into a dropout portion of the video signal. 4. In claim 3, the warning means:
A video signal reproducing device comprising a changeover switch for switching between activation and deactivation of the signal insertion means. 5. In claim 1, the reproducing means comprises:
first and second reproduction pickups that respectively reproduce first and second field signals recorded on two tracks on the recording medium; , a first changeover switch that switches the second field signal for each field and outputs it to the dropout detection means; and a first changeover switch that is connected to the first and second pickups, and that switches the first and second field signals to the dropout detection means. The dropout compensating means includes a second changeover switch that switches and outputs field by field in the reverse order of the first changeover switch, and the dropout compensating means is configured to switch the second changeover switch when the dropout detection means detects a dropout. A video signal reproducing device characterized in that dropout compensation is performed using the output of a changeover switch. 6. In claim 5, a delay circuit connected to the output end of the first changeover switch and the output of the first changeover switch and the delay according to the output of the dropout detection means. A video signal reproducing device comprising a third changeover switch that selects and outputs one of the outputs of the circuit.