JPH0762927B2 - Control signal generator and its signal separator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control signal generator for generating a control signal used for tracking control during reproduction in a video tape recorder or the like, and a video signal editing from the control signal. The present invention relates to a reference signal separation device that separates the reference signal.

2. Description of the Related Art In recent years, along with the high performance of video tape recorders, digital video tape recorders that digitize and record video signals and high-definition video tapes that record video signals with higher definition image information Recorders are being commercialized. In these video tape recorders, the bandwidth of the signal to be recorded is several times that of an analog video signal recorded by a conventional analog video tape recorder (the digitized video signal is
There is about 10 times the analog video signal). Since the shortest recording wavelength that can be recorded on the video tape is limited by the performance of the video tape and the recording / reproducing head, the relative speed between the video tape and the recording / reproducing head is required to record a digitized video signal or high-quality video signal. Need to be raised and recorded. As a specific method of increasing the relative speed between the video tape and the recording / reproducing head, there is a method of increasing the diameter of the rotating drum to which the recording / reproducing head is attached, or a method of increasing the rotating speed of the rotating drum. With the method of increasing the diameter of the rotating drum, the diameter of the rotating drum must be increased by N times in order to increase the relative speed by N times. Therefore, the video tape recorder becomes large in size, and it becomes a portable video tape recorder. Is unsuitable and disadvantageous in terms of space merit. Therefore, at present, a method of increasing the rotation speed of the rotating drum is often used. When the rotation speed of the rotary drum is increased, one field period of the video signal does not correspond to one track, and one field period of the video signal is recorded on a plurality of tracks. This recording method is called segment recording.

Generally, in a video tape recorder, it is necessary for the reproducing head to accurately trace the recorded track, which is called tracking. As a tracking method, a signal indicating the rotational position of a recording head for recording a video signal (hereinafter, this signal is referred to as a control signal) is recorded in the longitudinal direction of the video tape, and the control signal is reproduced during reproduction. There is a method for tracking by detecting the position of the track on which the video signal is recorded and adjusting the phase difference between the phase of this control signal and the phase of the head for reproducing the video signal.

Also, in a video tape recorder, it is possible to newly record a video signal after the video signal already recorded on the video tape or insert a new video signal in the middle of the video signal already recorded on the video tape. And this action is called editing. At that time, so that the reproduced image is not disturbed at the time of reproduction at the joint between the recording of the already recorded video signal and the newly recorded video signal,
Recording is performed in synchronization with the recorded video signal and the newly recorded video signal. Generally, there are a case where synchronization is performed in a frame cycle and a case where a subcarrier signal of a color signal is also synchronized as a frame signal at the same time. Since a video signal transmits a color signal, a subcarrier signal is used, and the phase of this subcarrier signal does not return to the original one frame period of the video signal. The cycle in which the phase returns to the original is 2 frame cycles for the NTSC video signal and 4 frame cycles for the PAL video signal. This cycle is called a color frame cycle, and a group of frames in the color frame cycle is called a color frame. The first frame of the color frame is defined by the horizontal sync signal at a predetermined position and the phase of the subcarrier. Therefore, as a method of synchronizing an already recorded video signal with a newly recorded video signal, a frame signal (or a color frame signal) separated from the newly recorded video signal and the already recorded video signal Generally, a method of synchronizing with a recorded control signal is used. At this time, if the control signal is recorded at the same cycle as the frame signal (or color frame signal) of the video signal, synchronization can be easily achieved. However, the control signal is recorded during playback while tracking the video. Since it becomes a reference signal for running the tape, a higher frequency can improve frequency characteristics in the control system for running the video tape, and the running of the video tape can be stabilized. Further, in the above-mentioned segment recording type video tape recorder, since the track width on which the video signal is recorded is narrowed, more stable tape running is required so that the reproducing head traces the recording track accurately. Therefore, in order to increase the frequency of the control signal and synchronize with the control signal during editing, the control signal is recorded simultaneously with the signal that serves as a reference for tape running and the information for the reference signal during editing, and the tape running reference during playback is recorded. The signal and the reference signal at the time of editing are separated and used for the above-mentioned respective purposes (tape running reference and editing).

As a video tape recorder using the segment recording method, there is a D1 format video tape recorder that was standardized as a digital video tape recorder for broadcasting at the general meeting of the International Wireless Communication Advisory Committee in 1986. In the D1 format, one tape running reference point is recorded by the control signal for four tracks. When recording NTSC video signals, one frame video signal is 20
It is divided into tracks and recorded. Therefore, one reference signal showing the beginning of a frame of a video signal appears at five reference points of tape running, and a reference signal showing the beginning of a color frame of a video signal at ten reference points of tape running. One appears.

FIG. 7 shows the waveform of the control signal in the D1 format. The pulse shown in FIG. 7 (q) is formed as shown in FIG. 7 (p) at a predetermined cycle (1150 sec) as a reference point of tape running, and continuously pulsed to the position shown in FIG. 7 (p). If there is a pulse, it indicates the beginning of the video signal frame together with the tape running reference point, and if there is a pulse at the position shown in Fig. 7 (p), the tape running reference point together with the audio frame (audio signal continuity of the video signal The start of the color frame of the video signal is shown together with the reference point of the tape running if there is a pulse at the position of (c) in FIG. T represents 1/64 hours of the period of the recorded signal as a reference of tape running. The above signals are recorded in the longitudinal direction of the video tape by the bias recording method.

Recording and reproducing the control signal as described above
D1 format video tape recorder drum motor,
A block diagram of a system for controlling the capstan motor is shown in FIG.

301 is an input terminal for inputting a video signal to be recorded, 302 is a sync signal separating device for separating a frame signal 316 and a color frame signal 317 from the input video signal, 303 is synchronous with the frame signal 316, and has a frequency of 150 Hz. Driving reference signal
A traveling reference signal generator that generates 318, 304 is a frame signal 316, a color frame signal 317, and a traveling reference signal that are input.
A control signal generator for generating the control signal shown in FIG. 7 from 318, a video tape 305, a rotary drum 306 to which a video signal recording / reproducing head (not shown) is attached, and a capstan 307 for transferring the video tape. , 3
08 is a drum motor that rotates the rotary drum 306, 309 is a capstan motor that rotates the capstan 307, 310 is a servo device that controls the rotation speed and rotation phase of the drum motor 308 and the capstan motor 309, and 311 is a control signal. A control signal recording / reproducing head for recording / reproducing, a recording amplifier 312 for performing bias recording of the control signal generated by the control signal generating device 304, and a control signal reproduced by the control signal recording / reproducing head 311 for reference numeral 313 in FIG. A reproduction amplifier for reproducing the waveform as shown, 314 connects the control signal recording / reproducing head 311 to the recording amplifier 312 when recording the control signal,
A switch connected to the reproduction amplifier 313 when reproducing the control signal, and 315 is a frame signal 319 and a color frame signal 32 from the control signal reproduced by the reproduction amplifier 313.
0, a reference signal separating device for separating the traveling reference signal 321.

The operation of the motor control system configured as above will be described below.

First, the operation when recording the control signal will be described. When a video signal is input to the input terminal 301, the sync signal separation device 302
Separates the frame signal 316 and the color frame signal 317 from the input video signal, and the control signal generator 30
4, Supply to the traveling reference signal generator 303 and the servo device 305. The travel reference signal generator 303 generates a 150 Hz travel reference signal 318 synchronized with the input frame signal and supplies it to the servo device 310 and the control signal generator 304. Then, the servo device 310 rotates the drum motor 308 so that the video signal recording / reproducing head (not shown) and the traveling reference signal 318 have a predetermined phase, and causes the capstan motor 309 to keep the video tape transfer speed constant. Rotate so that In addition, the control signal generator 304 is the seventh
Generating the control signal shown in the figure, the recording amplifier 312
Supply to. The recording amplifier 312 applies a bias to the input control signal and supplies it to the control signal recording / reproducing head 312 via the switch 3 so that the control signal is recorded on the video tape 305. At the same time, the video signal input to the input terminal 301 is recorded on the video tape 305 by the video signal recording head (not shown) attached to the rotary drum 306 via the video signal processing circuit (not shown) of the recording system. It

By the operation as described above, the rotation of the motor is controlled and the control signal is recorded.

Next, the operation during editing will be described. During editing, the recorded video signal is reproduced in synchronism with the newly recorded video signal, and then the recording operation is started.

When a video signal to be newly recorded is input to the input terminal 301, the sync signal separation device 302 and the traveling reference signal generation device 303 perform the same operation as at the time of recording. Then, the control signal recording / reproducing head 311 reproduces the control signal from the video tape 305, supplies it to the reproducing amplifier 313 via the switch 314, and the control signal having the waveform as shown in FIG. It The reference signal separation device 315 separates the frame signal 319, the color frame signal 320, and the running reference signal 321 from the reproduction control signal to separate the servo device 310.
Supply to. The servo device 310 rotates the drum motor 308 in the same manner as during recording, and the reproduction reference signal 321 separated from the reproduction control signal by the reference signal separation device 315 and the travel reference signal 318 generated from the travel reference signal generator 303.
And have a constant phase, and the playback frame signal separated from the playback control signal by the reference signal separator 315.
The capstan motor 309 is rotated so that 319 (or the color frame signal 320) and the frame signal 316 (or the color frame signal 317) separated from the video signal newly recorded by the synchronization signal separation device 302 have a constant phase.

As described above, the recorded video signal is reproduced in synchronization with the newly recorded video signal. By recording a video signal to be newly recorded on the video tape 305 after reproducing in this state, it is possible to connect the already recorded video signal and the video signal to be newly recorded without disorder.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the bias recording method, a peaking coil, a bias signal generation circuit, etc. are provided in comparison with a saturation recording method used for recording a control signal in a conventional analog video tape recorder or the like. It is necessary and the circuit scale is large. Therefore, recording the control signal by the saturation recording method is useful because the circuit scale can be reduced. However, in the saturation recording method, since the frequency of the control signal is raised and the control signal synchronizes during editing, the information of the reference signal at the time of editing as well as the signal serving as the reference of the tape running is simultaneously recorded in the control signal, and the tape is reproduced at the time of reproduction. The reference signal for running and the reference signal for editing have not been separated and used for the above-mentioned respective purposes (reference and editing for tape running).

The present invention is to solve the above-mentioned conventional problems, has a frequency higher than the frequency (frame frequency, color frame frequency) of a reference signal for editing a video signal, and includes information of the reference signal at the time of editing, A control signal generator that generates a control signal suitable for the saturation recording method,
Provided is a reference signal separating device for recording / reproducing a control signal generated by the control signal generating device and separating a reference signal for editing a video signal from the reproduced control signal, thereby reducing the circuit scale of the control signal recording / reproducing system. The purpose is to

Means for Solving the Problems The present invention synchronizes a first reference signal having a predetermined frequency, at a frequency N times (N is a natural number of 2 or more) times the frequency of the first reference signal, and A first reference signal having a duty ratio of 1 and a third signal having a second duty ratio different from the first duty ratio in synchronization with the second reference signal are created. Signal generating means, and second signal generating means for synchronizing with the second reference signal and generating a fourth signal having a third duty ratio different from the first and second duty ratios, And a switching unit that receives the first and second reference signals and switches the second reference signal, the third signal, and the fourth signal in a predetermined order in a cycle of the second reference signal. To be done.

Further, according to the present invention, a multiplication means for multiplying the control signal by two, a first division means for dividing the output signal of the multiplication means to the frequency of the first reference signal, and the first division means. A second frequency-dividing the output signal to the frequency of the second reference signal
Frequency division means, first duty ratio detection means for detecting a first duty ratio of the control signal, and second duty ratio detection means for detecting a second duty ratio of the control signal, The first frequency division means and the second frequency division means are preset to a predetermined state by the output signals of the first duty ratio detection means and the second duty ratio detection means.

Action The present invention has the above-described configuration, and the control signal generator of the present invention creates the third signal having the second duty ratio by the first signal creating means and the third signal by the second signal creating means. And a third signal having a second duty ratio, and a third signal having a second duty ratio by the switching means. The control signal is generated by switching the held fourth signal. The change in duty can be represented by two values and can be recorded by saturation recording.

Then, the reference signal separation device of the present invention detects the change of the duty of the input control signal by the first and second duty ratio detection circuits, and divides the frequency of the first frequency divider circuit and the second frequency divider circuit. The reference signal is separated by controlling the timing. The reference signal is the frequency N of the control signal.
(N is an integer of 2 or more) times, and the phase of the change in the duty of the reference signal and the control signal is known at the time of recording the control signal, so the reference signal can be separated from the control signal.

Embodiment An embodiment in which the present invention is applied to a video tape recorder for recording an NTSC video signal and a tape traveling reference signal is recorded at a frequency three times as high as a frame signal will be described below with reference to the drawings. explain.

FIG. 1 is a block diagram of a recording control signal generator for generating a control signal according to the present invention. Reference numeral 1 is an input terminal to which a color frame signal a synchronized with a recording video signal is input, 2 is an input terminal which is synchronized to a recording video signal, and a reference signal b having a frequency three times as high as that of the frame signal is input. The color frame signal a and the reference signal b are input, and the first gate signal c which becomes high for one cycle of the reference signal b from the rising of the color frame signal a and the half cycle of the color frame cycle from the falling of the color frame signal The gate signal generation circuit 4 for generating the second gate signal d which becomes high for one cycle of the reference signal b at the delayed position is supplied with the reference signal b and is synchronized with the reference signal b, for example, a signal e having a duty ratio of 6: 4. 6: 4 duty signal generating circuit,
Reference numeral 5 is a 4: 6 duty signal generating path for inputting the reference signal b and generating a signal f having a duty ratio of 4: 6 in synchronization with the reference signal b, and 6 is a first gate signal output from the gate signal generating circuit 3. An AND circuit that ANDs the inverted signal of c, the inverted signal of the second gate signal d, and the reference signal b input to the input terminal 2, 7 is the first gate signal c and the 6: 4 duty signal generation circuit AND circuit for taking the logical product of the output signal e of 4 and 8, AND circuit for taking the logical product of the output signal f of the 4: 6 signal generating circuit 5 of the second gate signal d, 9 AND circuits 6, AND circuits 7, an OR circuit that takes the logical sum of the output signal of the AND circuit 8 and 10
Is an output terminal from which the output g of the OR circuit is derived. Here, the block 100 surrounded by a dotted line is a switching unit.

The operation of the control signal generator configured as described above will be described with reference to the time chart of FIG.

The color frame signal a as shown in FIG.
Is input, and a signal b having a duty ratio of 5: 5 having a frequency three times that of the frame signal as shown in FIG.
(Hereinafter referred to as the reference 90 signal), the gate signal generation circuit 3 receives the first signal as shown in FIGS. 2c and 2d.
The gate signal c and the second gate signal d are generated. The 6: 4 duty signal generation circuit 4 generates a signal e as shown in FIG. 2e having a duty ratio of 6: 4 in synchronization with the reference 90 signal b input to the input terminal 2. At the same time, the 4: 6 duty signal generation circuit 4 uses the reference input to the input terminal 2.
A signal d as shown in FIG. 2d having a duty ratio of 4: 6 is generated in synchronization with the 90 signal b. Then, the AND circuit 6 extracts the reference 90 signal b while the first gate signal c and the second gate signal d are both low, and the AND circuit 7 outputs 6: 4 while the first gate signal c is high. The duty signal e is extracted, and the AND circuit 8 extracts the 4: 6 duty signal f during the high period of the second gate signal d. And A
By adding the output signals of the ND gates 6, 7, 8 by the OR gate 9, a recording control signal g is obtained at the output terminal 10 as shown in FIG. The generated control signal is recorded in the longitudinal direction of the video tape by the saturation recording method. In FIG. 2g, the rising edge of the control signal serves as a reference signal for tape running, and the duty ratio is 6:
The rising edges of the 4 and 4: 6 signals indicate the beginning of a frame, and the rising edges of the signal with a duty ratio of 6: 4 indicate the beginning of a color frame.

As described above, according to the control signal generator of this embodiment, the tape traveling reference signal is recorded at a frequency three times as high as that of the frame signal, and the reference signal (frame signal, color frame) for editing the recorded video signal is recorded. Signal) information can be recorded in the control signal.

Next, a reference signal separating device for extracting a frame signal and a color frame signal from a video tape recorder in which a control signal generated by the control signal generating device according to the embodiment of the present invention is recorded will be described.

FIG. 3 is a block diagram of the reference signal separation device. Reference numeral 11 is an input terminal to which the control signal h reproduced from the video tape is input, 12 is an input terminal to which a signal indicating the running direction of the video tape is input, and 13 is a doubling circuit for doubling the input control signal h. , 14 detects that the low period of the input control signal h is 0.45 times or less of one cycle of the control signal, and generates a pulse, the first low period detection circuit, and 15 indicates the input control signal h. A second row period detection circuit 16 which detects that the row period is 0.55 or more of one cycle of the control signal and generates a pulse, 16 divides the output signal k of the frequency doubler circuit 12 by 3 and the first row The output signal i of the period detection circuit 14 and the second
A frequency division circuit 3 which is preset by the pulse of the output signal j of the low period detection circuit 15 and has a divided output s rising from low to high at the next output pulse of the frequency doubler circuit 17,
Divides the output signal s of the divide-by-3 circuit 16 by 2 and
Of the output signal i of the row period detection circuit 14 and the output signal j of the second row period detection circuit 15 when the tape traveling direction is positive in accordance with the tape traveling direction signal input from the input terminal 12. A divide-by-2 circuit that is preset to high and preset to low when in the negative direction divides the output signal m of the divide-by-two circuit 17 by 2 and responds to the tape running direction signal input from the input terminal 12. When the tape running direction is positive, the pulse is preset to high by the pulse of the output signal i of the first row period detecting circuit 14 and low by the pulse of the output signal j of the second row period detecting circuit 15, and the tape running is performed. When the direction is a negative direction, a divide-by-2 circuit preset to low by the pulse of the output signal i of the first row period detection circuit 14 and high by the pulse of the output signal j of the second row period detection circuit 15, 19 is the output signal m of the divide-by-2 circuit 17 Output terminal that, 20 is an output terminal that is led to the output signal n of the divide-by-two circuit 18. Here, the block 200 surrounded by a dotted line is the first frequency dividing means, and the divide-by-2 circuit 18 is the second frequency dividing means.

The operation of the reference signal separation device configured as described above will be described below.

First, the operation when the video tape is running in the forward direction (the same direction during recording) will be described with reference to the time chart of FIG. When the video tape is running in the forward direction, the control signal h having the waveform as shown in FIG. 4h is reproduced. When a reproduction control signal h as shown in FIG. 4h is input to the input terminal 11, the doubler circuit 13 outputs pulses at both edges of the control signal h, and the control signal h is doubled as shown in FIG. 4k. The output signal k is output.
The row period detection circuit 14 detects the row period of the input control signal h, and the period is 1 of the control signal h.
If it is less than 0.45 times the period, a pulse is output and
Signal i is output. Further, the row period detection circuit 15 detects the row period of the input control signal h, outputs a pulse when the period is 0.55 times or more of one cycle of the control signal, and outputs a signal j as shown in FIG. 4j. Output. The divide-by-3 circuit 16 outputs the output signals of the row period detection circuits 14 and 15.
The output signal s is made low by the pulse of i, j, and the output signal k of the doubler circuit 13 is divided by 3 so that it rises to high at the next output pulse of the doubler circuit 13, and the signal s is changed as shown in FIG. 4s. Output. The divide-by-2 circuit 17 determines that the video tape running direction is the positive direction from the input signal from the input terminal 12, and raises the output signal m by the pulses of the output signals i and j of the low period detection circuits 14 and 15. While presetting, the output signal s of the divide-by-3 circuit 16 is divided into two, and a signal m as shown in FIG. 4m is output. Similarly, the divide-by-2 circuit 18 determines that the video tape running direction is the positive direction from the input signal from the input terminal 12, and the output signal i of the row period detection circuit 14 is pulsed to make the output signal high,
The output signal j of the row period detection circuit 15 is preset to low by the pulse of the output signal j, and the output signal m of the divide-by-2 circuit 17 is divided by 2 to output a signal as shown in FIG. Fourth
As is apparent from FIGS. M and n, the frame signal separated from the control signal is obtained at the output terminal 19, and the color frame signal separated from the control signal is obtained at the output terminal 20.

Next, the operation when the video tape is running in the negative direction (direction opposite to that during recording) will be described with reference to the time chart of FIG. When the video tape is running in the negative direction, the control signal h having the waveform as shown in FIG. 5h is reproduced. When the reproduction control signal h as shown in FIG. 5h is input to the input terminal 11, the doubler circuit 13 outputs pulses at both edges of the control signal h, and the control signal h is doubled as shown in FIG. 5k. The output signal k is output. The low period detection circuit 14 detects the low period of the input control signal h, outputs a pulse when the period is 0.45 times or less of one cycle of the control signal h, and outputs a signal i as shown in FIG. 5i. To do. Further, the row period detection circuit 15 detects the row period of the input control signal h, outputs a pulse when the period is 0.55 times or more of one cycle of the control signal h, and outputs a signal j as shown in FIG. Is output. The divide-by-3 circuit 16 outputs the output signals of the row period detection circuits 14 and 15.
The output signal is made low by the pulse of i and j, the output signal k of the doubler circuit 13 is divided into three so that it rises to high at the next output pulse of the doubler circuit 13, and the signal s is output as shown in FIG. 5s. To do. The divide-by-2 circuit 17 determines from the input signal from the input terminal 12 that the video tape running direction is the negative direction, and the output signal m is made low by the pulse of the output signals i and j of the row period detection circuits 14 and 15. At the same time as presetting, the output signal s of the divide-by-3 circuit 16 is divided into two to output a signal m as shown in FIG. Similarly, the divide-by-two circuit 18 determines from the input signal from the input terminal 12 that the video tape running direction is the negative direction, and the output signal i of the row period detection circuit 14 is pulsed to set the output signal n to low, The output signal n is preset to a high level by the pulse of the output signal j of the low period detection circuit 15, the output signal m of the divide-by-2 circuit 17 is divided into two, and a signal as shown in FIG. As is clear from Fig. 5 m and n, the frame signal separated from the control signal is obtained at the output terminal 19
A color frame signal separated from the control signal is obtained at 20.

As shown in FIGS. 4 and 5, a frame signal that rises and falls at the same position with respect to the duty ratio change of the reproduction control signal, regardless of whether the video tape runs positively or negatively,
Color frame signals can be separated. Therefore, it is possible to synchronize the separated frame signal and color frame signal with the frame signal and color frame signal separated from the external video signal, and it is possible to easily and neatly edit. Further, when the tape running direction is positive, the rising edge of the reproduction control signal is used as the standard for tape running, and when the tape running direction is negative, the falling edge of the playback control signal is used as the standard for tape running. A reference signal for tape running can be obtained at twice the frequency, and stable tape running can be realized.

In the frame signal / color frame signal separation circuit according to the present embodiment, the row period detection circuits 14 and 15 are configured to count clock signals (for example, capstan frequency signals) proportional to the tape running speed. Even if it changes, the frame signal and the color frame signal can be separated.

Further, the row period detection circuits 14 and 15 may be configured so that the cycle of the input control signal is counted and the result is calculated and used as the reference for detecting the duty ratio.

Further, the change of the duty ratio of the control signal can be realized by a simple circuit change even if the duty ratio of 6: 4, 4: 6 in this embodiment is changed to, for example, 7: 3, 3: 7.

It should be noted that the reference signal separating device can be configured by a microcomputer, and since a microcomputer is used for controlling a motor of a video tape recorder in recent years, if it is shared with the microcomputer, the circuit scale becomes small and it is useful. .

In this embodiment, the waveform of the control signal differs depending on the tape running direction. However, as shown in FIG. 6, if the duty ratio changing position of the control signal is compared with the center position r of the color frame signal. Since the position of the duty ratio change of the reproduction control signal waveform is the same whether the tape running direction is positive or negative, means for changing the preset state of the first and second frequency dividing means depending on the tape running direction is required. Therefore, the configuration of the reference signal separation device can be simplified.

Further, in the present embodiment, the case has been described in which the tape traveling reference signal is recorded at a frequency three times as high as the frame signal, but the tape traveling reference signal is another multiple of the frame signal, for example, four times, five times, or the like. The present invention can be applied even when recording is performed at a frequency that is an integer multiple of 2 or more.

Further, when applied to a video signal of a television system other than the NTSC system, for example, a PAL system video signal, the frame frequency is 25 Hz and the color frame frequency is 6.25 Hz, but the first frequency dividing circuit and the second frequency dividing circuit are used. Simple changes can be applied simply by changing the division ratio of the frequency circuit or the preset state.

As described above, according to the control signal generator of the present invention, the control signal generator has a frequency higher than the frequency (frame frequency, color frame frequency) of the reference signal for editing the video signal,
Further, it is possible to generate a control signal including information of the reference signal at the time of editing and suitable for the saturated recording method. According to the reference signal separating device of the present invention, the reference signal for editing the video signal from the reproduced control signal. Can be separated, and the circuit scale of the control signal recording / reproducing system can be reduced, and the effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram of a control signal generator in an embodiment of the present invention, FIG. 2 is a time chart for explaining the operation of the control signal generator, and FIG. 3 is a reference signal separation device in an embodiment of the present invention. Block diagram, 4th
5 and 5 are time charts for explaining the operation of the reference signal separator, FIG. 6 is a time chart showing a second example of the duty ratio change of the control signal, and FIG. 7 is a waveform showing the control signal in the DI format. FIG. 8 is a block diagram showing the control system of the video tape recorder. 3 …… Gate signal generation circuit, 4 …… 6: 4 duty signal generation circuit, 5 …… 4: 6 duty signal generation circuit, 6,7,8…
… AND circuit, 9 …… OR circuit, 13 …… Doubler circuit, 14,15…
… Low period detection circuit, 16 …… 3 frequency divider circuit, 17,18 …… 2
Divider circuit.

Claims (7)

[Claims] 1. A frequency synchronized with a first reference signal having a predetermined frequency, which is N (N is a natural number of 2 or more) times the frequency of the first reference signal, and has a first duty ratio. The second reference signal that I had and this second reference signal,
First signal generating means for generating a third signal having a second duty ratio different from the first duty ratio, and the first and second duty ratios in synchronization with the second reference signal. Second signal producing means for producing a fourth signal having a third duty ratio different from that of the first and second reference signals, and the second reference signal and the third signal And a switching means for switching and outputting the fourth signal in a predetermined order at a cycle of the first reference signal. 2. The first duty ratio of claim 1 is 5:
5, a control signal generator having a second duty ratio of M: L and a third duty ratio of L: M (where M and L are M
≠ L ≠ 5 positive value). 3. The switching means according to claim 1, wherein in the first half cycle of the first reference signal, only one cycle of the third signal is switched to the third signal and the other to the second reference signal. A control signal generator for switching to the fourth signal and outputting the second reference signal only for one cycle of the fourth signal in the next 1/2 cycle of the first reference signal. 4. The switching means according to claim 3 first switches to the third signal in the first half cycle of the first reference signal, and first to the fourth signal in the next half cycle. Control signal generator characterized by switching to. 5. A multiplication means for multiplying the control signal by two, and a first frequency division means for dividing an output signal of the multiplication means by a first division ratio.
Frequency dividing means, second frequency dividing means for dividing the output signal of the first frequency dividing means by a second frequency dividing ratio, and first frequency detecting means for detecting a first duty ratio of the control signal. A duty ratio detecting means; and a second duty ratio detecting means for detecting a second duty ratio of the control signal, wherein the output signals of the first duty ratio detecting means and the second duty ratio detecting means A signal separation device in which the first frequency dividing means and the second frequency dividing means are preset so that the frequency dividing timings of the first frequency dividing means and the second frequency dividing means are synchronized. 6. A multiplication means for multiplying a control signal by two, and a first division means for dividing an output signal of the multiplication means by a first division ratio.
Frequency dividing means, second frequency dividing means for dividing the output signal of the first frequency dividing means by a second frequency dividing ratio, and first frequency detecting means for detecting a first duty ratio of the control signal. A first duty ratio detection means for detecting the second duty ratio of the control signal; and a second duty ratio detection means for detecting the second duty ratio of the control signal. Means and the second duty ratio detecting means output signals, the first frequency dividing means and the second
The first frequency dividing means and the second frequency dividing means are preset so that the frequency dividing timing of the frequency dividing means is synchronized, and when the tape running direction signal is in the reverse direction (or forward direction), the first frequency dividing means and the second frequency dividing means are preset. According to the output signals of the first duty ratio detecting means and the second duty ratio detecting means, the timing of the frequency division of the first frequency dividing means and the second frequency dividing means becomes the same as in the forward direction. A signal separation device in which the first frequency dividing means and the second frequency dividing means are preset. 7. The signal separating device according to claim 5, wherein the first and second duty ratio detecting means detects the duty ratio using a signal having a frequency proportional to the tape running speed.