JPS6327507Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention inserts a pattern signal for displaying characters, symbols, figures, etc. into the reproduction signal reproduced by a reproduction device, and then outputs this composite color video signal to the recording device. This invention relates to an image compositing device for recording images.

This kind of conventional image synthesis equipment usually uses color
In a playback device such as a VTR, the playback video signal is supplied to a separation circuit consisting of a filter, etc., and the FM
The modulated luminance signal and the low frequency converted chroma signal of, for example, 688 KHz are separated from each other by the above-mentioned separation circuit. This separated luminance signal is then demodulated, while the low frequency converted chroma signal is high frequency converted to a frequency of 3.58MHz. Thereafter, the demodulated luminance signal and the high frequency converted chroma signal are superimposed, and this superimposed signal (video signal) is output from the reproducing device via one supply line. At this time, in order to form an image with characters, symbols, figures, etc. inserted, a pattern signal for displaying the characters, symbols, figures, etc. is synthesized with the reproduced color video signal from the reproduction device in the above-mentioned supply line. , this composite color video signal passes through the supply line to the color
It is configured to be supplied to a recording device such as a VTR.

In this recording apparatus, the above-mentioned superimposed signal is supplied to a separation circuit comprising a filter or the like, and the luminance signal and chroma signal are separated from each other. The luminance signal is then FM modulated, while the 3.58 MHz chroma signal is down-converted to a frequency of 688 KHz, for example, and recorded on a recording medium such as a video magnetic tape.
In this way, a so-called dubbing operation is performed in which a color video signal recorded on a recording medium is recorded on another recording medium.

However, in the conventional image synthesis apparatus as described above, the reproduced color video signal reproduced by the reproduction apparatus is separated into a luminance signal and a chroma signal by a separation circuit consisting of a filter or the like in each of the reproduction apparatus and the recording apparatus. Therefore, there is an inconvenience that the frequency characteristics of the color video signal deteriorate when it passes through the separation circuit.

The present invention was devised in view of the above-mentioned actual situation, and it is possible to obtain a composite image in which characters, symbols, figures, etc. are inserted while keeping the low-frequency conversion chroma signal and the luminance signal separated from each other. The present invention provides an image synthesizing device which generates a synthesized luminance signal and a synthesized low frequency converted chroma signal, and supplies these synthesized signals separately to a recording device for recording. Therefore, according to the image synthesizing apparatus of the present invention, it is possible to suppress deterioration of the frequency characteristics of a synthesized color video signal that displays an image in which characters, symbols, figures, etc. are inserted as captions (patterns).

In this specification, the term "ticker" refers to characters, symbols, figures, etc. that are inserted and displayed on a part of the screen.

An embodiment of an image synthesis apparatus to which the present invention is applied will be described below with reference to the drawings.

FIG. 1 shows the configuration of the image compositing device of this embodiment.
It is composed of a VTR 1, a recording color VTR 2, and a color caption adapter 3 that combines signals for displaying characters, symbols, figures, etc. with the output signal from the reproduction color VTR 1. In the image composition apparatus of this embodiment, the reproduction color VTR 1
As will be described later, the FM demodulated luminance signal and the chroma signal, which has been low frequency converted to a frequency of, for example, 688 KHz, are separated from each other and supplied separately to the color caption adapter 3. That is, the dubbing terminal of the reproduction color VTR 1 is provided with two supply lines _Y1 and _C1 , and the reproduction luminance signal is supplied from the supply line _Y1 , and the reproduction luminance signal is supplied from the supply line _C1 .
A reproduced chroma signal is supplied from the Note that the color video signal from the reproduction color VTR 1 may be reproduced by the monitor television 6 so that the reproduced image can be viewed during dubbing.

Further, the color caption adapter 3 is supplied with a caption signal (pattern signal) for displaying characters, symbols, figures, etc. from the monochrome television camera 5, and the adapter 3 generates a color image in which the characters, symbols, figures, etc. are synthesized. A composite signal, ie, a composite luminance signal and a composite chroma signal, for displaying the image is generated. And these composite signals are the supply line
The signals are separately supplied through Y ₂ and C ₂ to a recording color VTR 2, where the above-mentioned composite signal is superimposed and recorded on a recording medium such as a video magnetic tape.

Here, the second part of the configuration of the reproduction color VTR1 is shown.
To explain with reference to the figure, first, the color video signal reproduced by the magnetic head 7 is supplied to a high-pass filter 8 and a low-pass filter 9, respectively.
This separates the luminance signal and chroma signal from each other. The brightness signal obtained from the high-pass filter 8 is FM demodulated by the demodulation circuit 10 and supplied to the mixer 11, and the brightness signal output terminal
Supplied to Y _OUT .

On the other hand, the low frequency converted chroma signal (frequency is, for example, 688 KHz) obtained from the low pass filter 9 is high frequency converted to a frequency of 3.58 MHz by the frequency converter 13 and is supplied to the mixer 11. The mixer 11 mixes the low frequency converted chroma signal and the FM demodulated luminance signal, and this mixed signal is sent to the amplifier 1.
2, the signal is amplified and supplied to the output terminal 20. The reproduced output signal obtained at the output terminal 20 is supplied to the monitor television 6 to reproduce the image.

Further, a part of the output signal of the frequency converter 13 is composed of a burst gate 14, a phase comparator 15, a reference signal generator 16, and a voltage controlled oscillator 17.
This signal is supplied to the APC (automatic phase control) circuit 18.
As will be described later, the APC circuit 18 supplies a continuous wave signal of 688 KHz, which is the same frequency as the low frequency converted chroma signal, to the output terminal CW _OUT and the frequency converter 19, respectively. A high-frequency converted signal obtained from this frequency converter 19 is supplied to the frequency converter 13.

Note that the frequency converter 13 converts the frequency ₁ (688KHz) of the low-pass converted chroma signal from the low-pass filter 9 based on the frequency ₂ of the output signal of the frequency converter 19.
It is configured to perform high frequency conversion to a frequency of ₂ − ₁ ,
The other frequency converter 19 is configured to high-frequency convert the frequency ₃ of the output signal from the APC circuit 18 to a frequency of ₃ + ₄ based on the frequency ₄ of the reference signal from the reference signal generator 16. . Therefore, the following formula holds.

₂ = ₃ + ₄ ...(1) ₅ = ₂ - ₁ = ( ₃ + ₄ ) - ₁ ...(2) (However, ₅ is the frequency of the output signal of the frequency converter 13.) Also, when the APC circuit 18 is locked If the APC circuit 18 is in the locked state, ₅ = ₄ , so from equation (2), ₄ = ( ₃ + ₄ ) - ₁ ∴ ₃ = _1. Therefore, from this, if the APC circuit 18 is in the locked state, the APC circuit 18 is in the locked state. 18 outputs a continuous wave signal having the same frequency as the frequency of the low frequency converted chroma signal, 688 KHz.

Next, the structure and operation of the color caption adapter 3 will be explained with reference to FIG.

First, the color caption adapter 3 is provided with a luminance signal input terminal Y _{IN and} a chroma signal _input terminal C _IN , respectively. The reproduced luminance signal is supplied through the supply line _Y1 , while the 688KHz low-frequency converted chroma signal from the output terminal _COUT of the VTR 1 mentioned above is supplied to the input terminal _CIN through the supply line _C1 . It's becoming like that. The luminance signal supplied to the input terminal _YIN is supplied to the terminal _a1 of the switching circuit 23 through the clamp circuit 21 and buffer amplifier 22. This switching circuit 23 is configured to be selectively switched to the terminal a ₁ or b ₁ side based on the output of the black and white television camera 5 as described later, and the switching circuit 23 is switched to the terminal a ₁ side based on the output. When the brightness signal is supplied from the reproduction color VTR 1, the brightness signal is sent to the clamp circuit 21, the buffer amplifier 22, and the switching circuit 23 at terminal _a1 .
and the buffer amplifier 24, and are supplied to the output terminal _YOUT of the color tape adapter 3.
Further, when the switching circuit 23 is switched to the terminal b ₁ side, the voltage signal from the adjustable voltage dividing circuit 26 passes through the buffer amplifier 27, the terminal b ₁ of the switching circuit 23, and the buffer amplifier 24 in sequence as a brightness signal to the output terminal Y. ′ Supplied to _OUT .

On the other hand, the low frequency converted chroma signal is processed by the buffer amplifier 2.
The terminal of the switching circuit 29 is amplified by 8.
a ₂ and also to a continuous wave generation circuit 33 consisting of a burst gate 30, a phase comparator 31, and a voltage controlled oscillator 32. The continuous wave signal obtained from this continuous wave generation circuit 33 is supplied to the terminal b ₂ of the switching circuit 29 through a phase adjuster 35 and a level adjuster 36, respectively, and this terminal b ₂ has a phase and level adjusted signal. Color subcarriers are obtained as described below. Note that this switching circuit 29 is configured to be selectively switched to terminal a ₂ or b ₂ from the output of the black and white television camera 5, as will be described later, in the same way as the switching circuit 23 described above. The signal passed through the buffer amplifier 37 is supplied to the output terminal C' _OUT .

Here, the circuit configuration related to the continuous wave generating circuit 33 will be described. The burst flag pulse is supplied to the burst gate 30 of the continuous wave generating circuit 33. That is, the luminance signal obtained from the clamp circuit 21 is supplied to the burst gate 30 through a sync signal separation circuit 38, a horizontal sync signal separation circuit 39, and a burst flag pulse generator 40, respectively. Therefore, the burst flag pulse synchronized with the horizontal synchronizing signal is supplied to the burst gate 30, and a 688 KHz burst signal generated in synchronization with the generation period of this burst flag pulse is obtained from the burst gate 30. This burst signal is fed to an APC loop comprising a phase comparator 31 and a voltage controlled oscillator 32. As a result, a phase-controlled continuous signal of 688 KHz is obtained from the voltage controlled oscillator 32 of the continuous wave generating circuit 32. This continuous wave signal is then supplied to a phase adjuster 35 for hue adjustment, and further supplied to a level adjuster 36 for color density adjustment. The color subcarrier signal whose phase and level have been adjusted in this manner is obtained at the terminal b ₂ of the switching circuit 29.

Next, the control circuits for the switching circuits 23 and 29 will be explained. As mentioned above, these switching circuits 23 and 29 are controlled to switch based on the output of the black and white television camera 5.

That is, the output signal of the black-and-white television camera 5 passes through a buffer amplifier 42, a clamp circuit 43, a comparator 44, and a buffer amplifier 45 in order, and then is sent to the NAND circuit 4.
6 input terminals. For example, when a video signal d as shown in FIG. 4 is supplied from the black and white television camera 5, the comparator 44 outputs a pulse signal e at the level of the reference voltage V _Ref as shown in FIG.
is obtained, and this pulse signal e is sent to the buffer amplifier 4.
5 and supplied to one input terminal of the NAND circuit 46.

Further, the output signal of the synchronization signal separation circuit 38 is supplied to a horizontal synchronization signal separation circuit 39 and a vertical synchronization signal separation circuit 48, respectively. The horizontal synchronizing signal and vertical synchronizing signal obtained from these separation circuits 39 and 48 are supplied to a blanking pulse generator 49, whereby a low level signal as shown in FIG. A blanking pulse f is obtained. This blanking pulse f is the NAND circuit 46
is supplied to the other input terminal of Therefore, from this NAND circuit 46, only when there is no blanking pulse f and the pulse signal e is present, that is, only when the video signal d is supplied from the black and white television camera 5 when it is not the blanking time. , 4th
A low level pulse signal g as shown in the figure is obtained from the NAND circuit 46. When the low-level pulse signal g is supplied from the NAND circuit 46 to the switching circuits 23 and 29, these switching circuits 23 and 29 are switched to the terminals b ₁ and b ₂ , respectively, and this pulse signal g is supplied. When not, the terminals can be switched to the a ₁ and a ₂ sides respectively.

The horizontal and vertical synchronization signals from the horizontal synchronization signal separation circuit 39 and the vertical synchronization signal separation circuit 48 are respectively supplied to the monochrome television camera 5, and are synchronized with the reproduction luminance signal from the reproduction color VTR 1.

Therefore, according to the color caption adapter 3 configured in this way, the output terminal Y' _OUT is connected to the reproduction color by the switching control of the switching circuit 23.
A composite luminance signal is obtained by combining the reproduced luminance signal from the VTR 1 and the luminance signal arbitrarily adjusted in brightness by the voltage dividing circuit 26. In addition, the output terminal C' _OUT receives a burst signal (688K) extracted in synchronization with the low frequency converted chroma signal from the color VTR 1 for reproduction and the video signal d from the black and white television camera 5 under the switching control of the switching circuit 29
A composite chroma signal is obtained by combining the phase and level adjusted color subcarrier signals (Hz) with each other. These composite luminance signals and composite chroma signals are then sent from the color caption adapter 3 to the recording color VTR 2 through supply lines Y ₂ and C ₂ , respectively.
and recorded on magnetic tape.

When the magnetic tape recorded in this way is played back, the video recorded on the magnetic tape for dubbing will be played back as is on the monitor screen, and the text captured by the black and white television camera 5 will be displayed on the monitor screen.
Symbols, figures, etc. will be displayed against the background of the above-mentioned reproduced video. At this time, the characters, symbols, figures, etc. were photographed with a black and white television camera 5, but the reproduced images of the characters, symbols, figures, etc. are color images, and the brightness, color, hue, etc. of this color image are different. It can be changed arbitrarily by adjusting the pressure circuit 26, phase adjuster 35, and level adjuster 36.

Although the present invention has been described above with reference to one embodiment, the present invention is not limited to this embodiment, and various modifications can be made based on the technical idea of the present invention.

For example, in this embodiment, the color caption adapter 3 is provided with a continuous wave signal generating circuit 33, but as shown in FIG.
The configuration may be such that a continuous wave signal of 688 KHz is supplied from the output terminal CW _OUT of the color tape adapter 3 to the phase adjuster 35 (see FIG. 2). In this case, the continuous wave generating circuit 33 shown in FIG. 2 can be omitted. Therefore, three output terminals
If a dubbing terminal consisting of Y _OUT , C _OUT , and CW _OUT is provided on a color VTR for playback, this image compositing device can be used to create a composite color image with characters, symbols, figures, etc. inserted. It can be obtained with a simple configuration. Note that it is also possible to superimpose it on a control line for controlling the continuous wave signal reproducing device and recording device.

Further, in this embodiment, the black and white television camera 5 is used as a signal generation source for generating pattern signals for displaying characters, symbols, figures, etc., but the present invention is not limited to this, and a normal VTR or pattern signal generator or the like may be used. You may use it.

As described above, the present invention is capable of controlling the switching of a predetermined switching circuit based on the output of a signal generation source that generates pattern signals for displaying characters, symbols, figures, etc. Characters,
A composite luminance signal and a composite chroma signal are created so that a screen in which symbols, figures, etc. are composited are created, and these composite signals are recorded by a recording device. Therefore, according to the image synthesis device of the present invention, there is no need to separate the luminance signal and chroma signal from each other using a separation circuit consisting of a filter or the like in the recording device, so that deterioration of the frequency characteristics of the synthesized color video signal can be suppressed. As a result,
A clear composite color image with captions inserted can be obtained.

[Brief explanation of the drawing]

The drawings show an embodiment of an image synthesizing device to which the present invention is applied, in which FIG. 1 is a block diagram showing the configuration of the image synthesizing device, FIG. 2 is a block diagram showing the circuit configuration of the reproducing device, and FIG. FIG. 3 is a block diagram showing the circuit configuration of the color caption adapter, and FIG. 4 is a waveform diagram for explaining the circuit operation for switching and controlling a pair of switching circuits based on the output of a black and white television camera. In addition, in the symbols used in the drawings, 1...
...Color VTR for playback, 2...Color for recording
VTR, 3...Color caption adapter, 5...
...black and white television camera, 23...switching circuit, 29...switching circuit, 35...phase adjuster, 36...level adjuster.

Claims (1)

[Scope of utility model registration request] Selecting one of a reproducing device that obtains a reproducing signal from a magnetic recording medium in which a chroma signal is low-frequency converted and recorded together with a luminance signal, and a luminance signal obtained from the reproducing device and an adjustable luminance level signal. a first switching means; and a second switching means for selecting one of the low-pass conversion chroma signal obtained from the reproduction device and the color subcarrier signal of the low-pass conversion frequency whose phase and level have been adjusted respectively; , a recording device configured to record the composite luminance signal and the composite low-frequency converted chroma signal obtained separately from the first and second switching means on separate magnetic recording media, each of which records characters, symbols or The first and second switching means are selectively switched based on the output of a signal generation source that generates a pattern signal for displaying a figure, etc., thereby inserting characters, symbols, figures, etc. An image synthesizing device characterized in that the recording device records a synthesized color video signal for displaying an image.