JPS5939946B2 - special effects equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a special effects device used in a television broadcasting device, and particularly to a special effects device that generates special effects using an electrical method.

Special effects equipment that performs processing such as dissolve, fade-in, fade-out, insert, life, chroma key, wipe key, positioning, etc. between two or more television signals uses a method (non-composite method) in which the video signal and synchronization signal are transmitted separately. ) was commonly used.

Recently, a method (composite method) for simultaneously transmitting a video signal, a synchronization signal, and a color burst signal has begun to be adopted, and it is thought that this method will become popular in the future.
In the above composite method, the video signal, synchronization signal, and color burst signal are processed by a single gain control circuit, so the phase between each signal can be maintained correctly, but the control system required for this is extremely complex. However, there was a problem that the reliability of the entire device was impaired. SUMMARY OF THE INVENTION An object of the present invention is to provide a special effects device that has a simple configuration, can provide various special effects, and can maintain correct phase relationships between signals.

In order to achieve the above object, a special effects device according to the present invention includes a plurality of channels including a video signal clamp circuit and a circuit for time-division processing of the output of the clamp circuit, and a time-division processing of the plurality of channels. a mixing circuit for mixing the outputs of the circuits, a plurality of means for generating control voltages for controlling the gain of the video signals of the plurality of channels, and a plurality of means for adding the control voltages of the respective channels and pulses indicating a synchronization signal period. The first non-adder circuit (NoneAdd
tiveMlxing circuit (hereinafter referred to as NAM), and a plurality of second non-adder circuits that receive the outputs of the plurality of first non-adder circuits, the output of the second non-adder circuits is time-divided for each channel. When supplied as a control voltage to the processing circuit, the pulse is configured to selectively supply one of the plurality of second non-addition circuits with a pulse that maintains the output of the burst period.

According to the above configuration, the control voltage generation circuit etc. are significantly simplified and the intended purpose is completely achieved. Hereinafter, the apparatus according to the present invention will be explained in more detail with reference to the drawings.

First, we will introduce a non-additive mixing circuit (hereinafter referred to as NOneAdditive Mixing circuit), which is a component of the control voltage generation circuit.
,・NAM) will be briefly explained.

Figure 1A shows a positive NAM circuit, a NAM circuit whose output level is the higher level of the input signal, and Figure 1B shows a negative NAM circuit.
1 shows a circuit whose output level is the lower level of the input signals.

1. FIGS. 2A and 2B are diagrams for explaining the respective operations. The positive NAM circuit consists of two NPN transistors and a common emitter of said transistors connected to the power supply -V.
Consists of a common emitter resistor connected between cc
It's leaking.

The collector of each transistor is connected to the power supply +Vcc. When waveform a shown in FIG. 2 is applied to the base of one transistor, and waveform b shown in FIG. 2 is applied to the other, an output c appears at the emitter.

The output c is the voltage drop Vb between the emitter and base of the transistor from the higher level of the two inputs A and B at each point in time.
It is the value obtained by subtracting e. Negative NAM circuit has two NPs
It consists of N transistors and a common emitter resistor connected between the common emitter of each of the transistors and the power supply +Vcc. Each collector is connected to power supply -Cc. Figure 2 a' at the base of one transistor.
When the output ♂ is added to the other side of the output ♂, the output ♂ appears at the emitter. The output ♂ has a value that is the sum of the lower level of the inputs a' and b' at each time point plus Vbe. j Next, an embodiment of the special effect device according to the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is a configuration diagram of the embodiment device, and FIG. 4 is a waveform diagram for explaining the operation.

1. When passing the color burst signal at full level through the base channel In Fig. 3, the channels of clamp 1 and time division processing circuit 2 are set as the base channel through which the central signal passes, and the channels of clamp v and time division processing circuit 2' are Let the channel be a superchannel that processes the signal mixed with the signal.

When the base channel contains the signal a shown in FIG. 4, the synchronization signal color burst signal, and the video signal, the super channel a', which contains the video signal different from a, is added, After the pedestal voltage is clamped to a certain DC level by clamp 1 and clamp V, each signal is applied to time division processing circuits 2 and 2', respectively. The time division processing circuits 2 and 2' time division process the respective input signals according to the signals G and g' from the control voltage generation circuits, respectively. Signals G and g' are generated as follows.

8 and 8' are signal generating circuits for adjusting the passing level of the time division processing circuit, respectively.

Reference numeral 8 denotes a signal generation circuit capable of sending signal voltages from EaOFF (voltage corresponding to setting the output of the time division processing circuit 2 to 0%) to EaFULL (voltage corresponding to 100%).

85 is a voltage from EaOFF (voltage corresponding to setting the output of the time division processing circuit 2' to 0%) to Ea/FULL (100%).
This is a signal generation circuit that can send signal voltages up to (voltage corresponding to %).

8's output b, voltage Ea, is negative NAM3, 8' output b
', voltage Ea, is supplied to negative NAM3'.

In addition, the signal c is applied to the other input terminal of each negative NAM 3, 37, EaOFF during the blanking period, and EaFULL. is applied, the output of each negative NAM has signals d and d
``When it is not the blanking period, a signal Ea, 0 appears, and these signals are applied to the positive NAMs 4 and 45, respectively. At the other input terminals of the positive NAMs 4, 4', the signal e is applied to the control logic 7. Signals f and F2 are respectively applied which are determined by the regulated switch 11.The control logic 7 is regulated by the micro-switches 9 and 9', which are respectively attached to 8 and 8'. Since the switch 11 is on the positive NAM4 side, f is equal to e and ν is zero.The positive NAM4 compares d and f and determines the control voltage g.The positive NAM42 compares d' and f.
'(=0) to synthesize the control voltage g''.The control voltage g is the blanking period and the burst period (EaFULL
), and the other periods are Ea, so the time division processing circuit 2 passes the burst signal at full level, multiplies the video signal by Ea/EaFULL, passes it, and sends out the output h.

On the other hand, the time division processing circuit 2/ which is regulated by g' sends out an output h'. These outputs are from signal a to switch 10,
Together with the signal 1 extracted through the synchronous reproduction 6, it is mixed in the mixing circuit 5 and converted into a waveform as shown in j.
The overall signal level is 8', the signal slope is freely adjustable at 8, and the color burst signal appears as is.
In the above device, the base channel and super channel can be easily switched by changing the switch 11 to the 4' side and the switch 10 to the a'' side.

2 Set the base channel blanking period to 100? If you want to pass the color burst, synchronization signal, etc. through the time division processing circuit at 100%, please refer to Figure 4 e.
It is sufficient to change the signal in the blanking period to an inverted blanking pulse, a pulse that is EaFULL during the blanking period, and there is no need to change other configurations.

From the above explanation, it can be seen that this special effect generating device works effectively as a fader. As described above, according to the present invention, television signals can be time-divisionally controlled by synthesizing various control signals, and although the circuit configuration is simple, it is suitable for producing faders and various other special effects. You can see that

Although detailed explanations have been given regarding specific examples above, various modifications are possible.

By increasing the number of input terminals of the NAM circuit, it is also possible to process more signals and synthesize control signals. For example, the outputs of B and b' are not limited to direct current,
By controlling the pulse waveform, special effects such as wipes and keys can be easily generated.

In short, the scope of the present invention is not limited to the examples, but extends to all of the claims.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of the NAM circuit, and FIG. 2 is a waveform diagram for explaining the operation of the NAM circuit. FIG. 3 is a configuration diagram of an embodiment of a special effect device according to the present invention;
FIG. 4 is a waveform diagram for explaining the operation of the above device. 1, v-t...clamp circuit, 2, 2ζ...
Time division processing circuit, 3, 3' 4, 4'...NA
M, 5...Mixing circuit, 6...Synchronized playback, 7...Control logic, 8, 8'...
Signal generation circuit, 9, 9'--... micro switch, 10, 11... change-over switch.

Claims (1)

[Claims] 1. A plurality of channels including a video signal clamp circuit, a circuit for time-division processing of the output of the clamp circuit, a mixing circuit for mixing the outputs of the time-division processing circuit of the plurality of channels, and a mixing circuit for mixing the outputs of the time-division processing circuit of the plurality of channels; a plurality of means for generating a control voltage for controlling the gain of a video signal of a channel; a plurality of first non-summing circuits for adding the control voltage of each channel and a pulse indicating a synchronization signal period; a plurality of second non-adding circuits receiving the output of the first non-adding circuit, and when supplying the output of the second non-adding circuit as a control voltage of the time division processing circuit of each channel, the plurality of second non-adding circuits A special effects device characterized in that it selectively supplies a pulse that maintains the gain of one burst period of the second non-summing circuit.