JPH0119791B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television special effects waveform generator.

Television special effects waveforms were obtained by mixing horizontal and vertical special effects waveforms and slicing them at predetermined levels of fader control voltages. However, conventional television special effect waveform generators of this type use limited types of horizontal and vertical fundamental waves, and are therefore limited in the types of waveforms they can generate.

An object of the present invention is to provide a special effect waveform generator that can generate a large number of special effect waveforms by using a limited fundamental wave and adding some processing to it.

In the present invention, by switching the horizontal and vertical period fundamental waves using a switching signal and inputting them to the first and second coefficient multiplication circuits, the coefficients by which the horizontal and vertical period fundamental waves are multiplied are changed. , 1st
The adder circuit adds the outputs of the coefficient multiplier circuit. The waveform shaping circuit receives the output of the first addition circuit, compares it with the fader control data, and outputs a special effect waveform signal, and the switching signal is generated by adding horizontal and vertical periodic sawtooth waves in the second addition circuit and comparing the results. It is obtained by comparing with the set value in the circuit.

Next, the present invention will be described in detail with reference to the drawings of an embodiment of the present invention. FIG. 1 is a diagram showing an embodiment of the present invention, in which the output of the horizontal periodic fundamental wave generating circuit 1 is H, the output of the vertical periodic fundamental wave generating circuit 2 is V, and these are connected to the first switching circuit 2 and the first switching circuit 2, respectively. The signals to be complementary switched in the second switching circuit 4 are φ ₁ and φ ₂ , the multiplication coefficient of the first coefficient multiplication circuit 5 that changes the level of the output of the first switching circuit 3 is a, and the multiplication coefficient of the second switching circuit 4 is φ 1 , φ 2 . The function and operation of each component will be explained in order, assuming that the multiplication coefficient of the second coefficient multiplication circuit 6 that changes the output level is b. In the figure, the outputs of the multiplier circuits 5 and 6 are added in a first addition circuit, and further compared with fader control data Df in a waveform shaping circuit 8 to output a special effect waveform signal. The switching signal is the comparator circuit 12
To do this, sawtooth wave generation circuits 9 and 10 generate horizontal and vertical sawtooth waves, the second addition circuit 11 adds them, and the comparison circuit 12 converts the addition result to the set value Dt. It is created by comparing.

First, the generation method of the switching signals φ ₁ and φ ₂ will be described. The level sawtooth waves shown in FIG. If this output is shown by equal level lines, it will be shown in Figure 2b, and the comparator circuit 1
2, the switching signals φ ₁ and φ ₂ are obtained by comparing with the set value (0 in this embodiment). Here, φ ₁ and φ ₂ are in an inverse relationship, and the first switching circuit 3
When the output of the second switching circuit 4 is H, the output of the second switching circuit 4 is V
And when the output of the first switching circuit 3 is V, the output of the second switching circuit 4 is H. Next, the outputs of the switching circuits 3 and 4 are multiplied by a and b in first and second coefficient multiplication circuits 5 and 6, respectively.
are added by the adding circuit 7. Therefore, as the output of the adder circuit 7, the following two values are selected by the switching signal and output.

H×a+V+b ……(1) H×b+V×a ……(2) Here, assuming that the fundamental waves H and V are parabolic waves, a>b
Then, as shown in FIG. 3, the output of the waveform shaping circuit 8 has a solid line inertia circle when the above equation (1) is selected, and (2)
When the formula is selected, the inertia circle of the line is output. Therefore, by selecting the waveform using the switching signals φ ₁ and φ ₂ , the special effect waveform shown by diagonal lines can be obtained. Also, by making the fundamental waves H and V triangular waves,
Similarly, a special effect waveform shown by diagonal lines in FIG. 4 is obtained.

As explained above, the present invention multiplies the fundamental wave by a coefficient to change the aspect ratio of the waveform, and changes the horizontal and vertical aspect ratios by switching the coefficient with an appropriate switching signal, thereby creating a special effect waveform. It has the effect of causing

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention;
Figure 2a shows the waveform generated by the horizontal and vertical periodic sawtooth wave generation circuit, b shows the output of the second adder circuit with equal level lines, and Figure 3 shows the case where a parabolic wave is used as the fundamental wave. FIG. 4 shows a special effect waveform when a triangular wave is used as the fundamental wave. In the figure, 1...horizontal periodic fundamental wave generation circuit, 2...
Vertical period fundamental wave generation circuit, 3...first switching circuit, 4...second switching circuit, 5...first coefficient multiplication circuit, 6...second coefficient multiplication circuit, 7...first
8...Waveform shaping circuit, 9...Horizontal periodic sawtooth wave generation circuit, 10...Vertical periodic sawtooth wave generation circuit, 11...Second addition circuit, 12...Comparison circuit.

Claims (1)

[Claims] 1. A horizontal fundamental data generation circuit that generates horizontal period fundamental wave data, a vertical fundamental data generation circuit that generates vertical period fundamental wave data, and the horizontal and vertical fundamental wave data are received and switched in a complementary manner by a switching signal. first and second switching circuits that perform
a first and second coefficient multiplication circuit that receives the outputs of the two switching circuits and multiplies each data by a coefficient; a first addition circuit that receives the outputs of the two coefficient multiplication circuits and performs addition; A waveform shaping circuit that receives the output, compares it with fader control data, and outputs a special effect waveform signal, a horizontal sawtooth wave generation circuit that generates sawtooth wave data with a horizontal period, and a sawtooth wave data with a vertical period. a vertical sawtooth wave generation circuit; a second addition circuit that receives and adds the horizontal and vertical sawtooth wave data; and a comparison circuit that compares the output of the second addition circuit with a set value and supplies the switching signal. A special effects waveform generator comprising: