JPS62207074A - Video mixer-amplifier - Google Patents

Abstract

PURPOSE:To provide two pieces of multiplier circuits and to enable an adder circuit to border-wipe with two-input addition by providing a switch circuit that receives and switches plural video signals, a key signal processing circuit, the first and the second multiplier circuits, and an adder circuit. CONSTITUTION:Under a border-wipe-ON control, the input video signal of the first multiplier circuit 3 is such a one that an input signal A and that B are switched at the boundary of a wipe-signal S1, while the input video signal to the second multiplier circuit 4 is an input signal BC. In the circuit 3, the video signal in which the input signals A and B are switched and a key signal that is generated by inversing a border signal, are multiplied. In the circuit 4, a border color signal (input signal BC) and a border signal S2 are multiplied. And the results of said two multiplications are added by the adder circuit 5, to obtain a picture by border-wiping the input signal A and that B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a television video mixing amplifier, and more particularly to a video mixing amplifier for use in wiping and border wiping.

[Conventional technology]

An example of a conventional video mixing amplifier of this type is shown in FIG. 4. In the figure, A, B, BC are input signals consisting of a plurality of video signals, Sl is a wipe signal, Ss is a border signal, and S4 is a border signal. This is the output video signal.

A key signal processing circuit 11 receives the wipe signal St and the border signal S and processes the key signal;
2, 13, and 14 are the first digits that receive input signals A, B, and BC and perform multiplication. The 2nd and 3rd multiplication circuits use the key signals processed by the key signal processing circuit 11 to
．． The third multiplier circuits 12, 13, and 14 perform keying, and the adder circuit 15 anvils the three outputs of the first to third multiplier circuits 12 to 14 to perform wipe and border wipe. It is configured to obtain an output video signal S4 on the output side of the .

The waveforms of the output key signal, input wide signal, and input border signal of this key signal processing circuit 11 are shown in FIGS. 5 and 6.

FIG. 5 shows the border wipe, and FIG. 6 shows the wipe.

And, respectively @) indicates an incoming active signal, and IP>
) indicates the input border signal, ←) indicates the key signal for the first multiplication circuit 12, 2) indicates the key signal for the second multiplication circuit 13, and color) indicates the key signal for the third multiplication circuit 14, respectively. .

[Problem that the invention seeks to solve]

In the conventional video mixing amplifier described above, the third
There is a problem that the multiplication circuit of
In order to obtain the key signals for the first and second multiplier circuits, there is a problem in that the key signal processing circuit needs to calculate the wipe signal and the border signal.

[Means for solving problems]

The video mixing amplifier according to the present invention includes a switching circuit that receives a plurality of video signals and performs switching between them, and a wipe signal, a border signal, and a border wipe control signal that are input to control the switching circuit and process key signals. A key signal processing circuit that performs multiplication, a first multiplication circuit and a second multiplication circuit that receive signals from the switching circuit and the key signal processing circuit, and outputs of the first and second multiplication circuits? It is designed to include an adder circuit that performs addition and obtains an output video signal.

[Effect]

In the present invention, we focus on the fact that the wipe boundary is keyed by the border signal and does not appear on the screen when wiping a border, and when wiping, we use a multiplication circuit to
When wiping a border, a switching circuit combines the two screens, and a multiplication circuit processes a portion of the border.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a block diagram showing an embodiment of a video mixing amplifier according to the present invention.

In FIG. 1, the same reference numerals as in FIG.
2 is a key signal processing circuit that controls the switching circuit 1 and processes the key signal as an input of a wipe signal Sl, a border signal St, and a border weige control signal Ssk; 3; 4 is a first multiplier circuit and a second multiplier circuit that receive signals from the switching circuit 1 and the key signal processing circuit 2 and perform multiplication, and 5 adds the outputs of the first and second multiplier circuits 3 and 4. This is an adder circuit that obtains the output video signal S4f.

Next, FIG. 2 shows the operation of the embodiment shown in FIG. 1.

This will be explained with reference to FIG.

FIGS. 2 and 3 are diagrams showing signal waveforms of various parts to explain the operation of FIG. 1. FIG. 2 shows the state at the time of wiping, and FIG. 3 shows the state at the time of border wipe. In FIG. 2, &) indicates an input cute signal, ←) indicates an input border signal, (c) indicates a key signal for the first multiplier circuit 3, and (n) indicates a key signal for the second multiplier circuit 4. In Fig. 3, 0) is the human cute signal, (b) is the input border signal, (c) is the switching signal for switching the video signal input to the first multiplier circuit 3, and 2) is the first The key signal for the multiplier circuit 3 and ←) indicate the key signal for the second multiplier circuit 4, respectively.

First, the operation of each part when performing a wipe will be explained with reference to FIG.

The border wipe control signal S3 gives border wipe OFF control to the key signal processing circuit 2, and the key signal processing circuit 2 controls the switching circuit to send the input signal A to the first multiplier circuit 3 and the second Input signal 81 to multiplier circuit 4
Control is performed to output each fc. In addition, in the key signal processing circuit, the first power 3! is used as the wipe signal Sxt input. A wipe signal is applied to the circuit 3, and the inverse of the wipe signal is applied to the second multiplication port jl&4 (see Figure 2, ←). The first and second multiplier circuits 3 and 4 perform keying using these key signals, and the addition circuit 5 adds the input signals to wipe the input signal A and input signal B (see Figure 2). ).

Next, the operation during border wipe will be explained with reference to FIG.

First, by controlling border wipe ON, the key signal processing circuit 2 generates a switching signal t that is used as the wipe signal Sl' to switch the video signal input to the multiplication circuit. That is, the input video signal of the first multiplication circuit 3 is the wipe signal S.
The input signal A and the input signal B are switched at the boundary of 1, and the input video signal of the second multiplication circuit 4 becomes the input signal BC (border color signal).

Next, in the first multiplication circuit 3, the video signal obtained by switching the input signal A and the input signal B is multiplied by a key signal obtained by inverting the border signal. Then, in the second multiplication circuit 4, the border color signal (input signal BC) is multiplied by the border signal S3. Then, by adding these two results in the adder circuit 5, the input signal A and the input signal B are
You can get a screen with i-border wiped.

Note that in the above embodiment, input signal A and input signal B
Although the description has been given by taking as an example the case where two-manpower switching is performed, the present invention is not limited to this, and a wipe signal for performing switching is added to the key signal processing circuit 2.
By adding an input signal to the switching circuit 1, it is also possible to switch the input signals, which are a plurality of video signals, and add a border to the input signals.

〔Effect of the invention〕

As explained above, according to the present invention, a multiplier circuit is used to perform two screens when wiping, so a soft wipe is also possible, and a switching circuit is used to perform two screens during a border wipe.
By compositing two screens and processing a portion of the border using a multiplier circuit, border wipe can be performed using two multiplier circuits and two adder circuits, so the practical effect is extremely large.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the video mixing amplifier according to the present invention, FIGS. 2 and 3 are waveform diagrams showing waveforms of various signals used to explain the operation of FIG. 1, and FIG. A block diagram showing an example of a video mixing amplifier, and FIGS. 5 and 6 are waveform diagrams showing waveforms of various signals for explaining the operation of FIG. 4. 1...Switching circuit, 2e--Key signal processing circuit, 3
, 4...Multiplication circuit, 5... Addition circuit. ″ to ? τ ? ) mouth

Claims (1)

[Claims] a switching circuit that inputs a plurality of video signals and switches between them; a key signal processing circuit that receives a wipe signal, a border signal, and a border wipe signal and controls the switching circuit and processes the key signal; and the switching circuit. The first circuit receives signals from the circuit and the key signal processing circuit and performs multiplication.
A video mixing amplifier comprising: a multiplier circuit, a second multiplier circuit, and an adder circuit that adds the respective outputs of the first and second multiplier circuits to obtain an output video signal.