JPH01225289A - Video signal synthesizer - Google Patents

Abstract

PURPOSE:To easily control by controlling the gain of the input video signal of two systems, further, adjusting a phase and switching the gain controlled signal and outputting. CONSTITUTION:The input video signals from input terminals 1-1, 1-2, 2-1, 2-2 are supplied to gain control circuits 5, 6 and switching circuits 3, 4. The output of the gain control circuits 5, 6 is supplied to phase adjusting circuits 15, 16 and switching circuits 13, 14. The output of the switching circuits 13, 14 are supplied to a gain control circuit 17. The gain control circuit 17 is controlled by a control signal from a phase adjusting circuit 12. Switching circuits 18, 19 switch the output of the phase adjusting circuits 15, 16 and the gain control circuit 17 to output an output video signal to output terminals 20, 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video signal synthesis device, and more particularly to a video signal synthesis device that synthesizes and outputs video signals used in television studio equipment.

[Conventional technology]

Conventionally, this type of video signal synthesis has been performed using input terminals 31-1, 31-2, 32-1, . . . as shown in FIG. 3 as a first example.
32-2. Switching circuit 33, 34° 35.36.41, 4
2, 43. 44, 47, 48. 55. 56. Phase adjustment circuit 37, 38, 39°40.49.50.53.54.
Gain control circuit 45.46. Control signal generation circuit 51.52
, and output terminals 57 and 58.

An input video signal is supplied to input terminals 31-1.31-2.32-1.32-2.

The input video signals of the input terminals 31-1 and 31-2 are respectively supplied to the switching circuits 33 and 34 together with the output signal of the gain control circuit 46.

These switching circuits 33 and 34 are switched depending on system conditions,
The output signals are supplied to switching circuits 41, 42 and phase adjustment circuits 37, 38, respectively.

The switching circuits 41 and 42 are switched according to the same system conditions as the switching circuits 33 and 34, and are respectively supplied to the gain control circuit 45.

The control signal generation circuit 51 supplies a control signal to the switching circuit 47 and the phase adjustment circuit 49. The switching circuit 47 is
It is switched according to the same system conditions as the switching circuits 41 and 42, and supplies a control signal to the gain control circuit 45. Further, the gain control circuit 45 supplies an output signal to a switching circuit 55 and a phase adjustment circuit 53. The output signal of the switching circuit 55 is supplied to the output terminal 57 as an output signal of the first system. Note that each phase adjustment circuit is used to impart a required phase to the input video signal in order to match the phases between the two switches.

Similarly, the input video signals at the input terminals 32-1, 32-2 are transferred to the switching circuits 35, 36, . Switching circuit 4 via phase adjustment circuit 39°40
3.44.

This output signal is supplied to gain control circuit 46.

The gain control circuit 46 includes a control signal generation circuit 52, a phase adjustment circuit 50. It is controlled by a control signal passed through a switching circuit 48. The output signal is then supplied to the switching circuit 56 via the phase adjustment circuit 54. This output signal is output from output terminal 58.
The output signal is output to the second system as an output signal.

As a second example of this type of video signal synthesis device, as shown in FIG.
2-2, it was composed of a switching circuit 69, 70.73°74, a phase adjustment circuit 67.68, a gain control circuit 63,64, 71, a control signal generation circuit 65, 66°72, and an output terminal 75.76. .

The input video signal is supplied to the gain control circuit 63 via input terminals 61-1 and 61-2. Moreover, input terminal 62-1.
The input video signal from 62-2 is supplied to gain control circuit 64.

Each of the gain control circuits 63 and 64 is a control signal generation circuit 6.
5.66, the output signal is controlled by the phase adjustment circuit 6
7.68 and switching circuits 69 and 70.

The output signals of the switching circuits 69 and 70 are supplied to a gain control circuit 71 and controlled by a control signal generation circuit 72. The switching circuits 73 and 74 switch the signals of the phase adjustment circuits 67 and 68 and the gain control circuit 71 to the first and second output terminals 75 and 76, respectively. It is output as an output video signal of the second system.

[Problem to be solved by the invention]

According to the first example of the conventional video synthesis apparatus described above, when a system in which gain control circuits 45 and 46 are continuously connected as shown in FIG. When viewed from the input terminal 31-1, the video system up to this point passes through the switching circuits 33, 41, 35, and 43, and four switching circuits, which has the drawback of deterioration of video characteristics and increased video phase delay. Moreover, since there are many switching circuits when switching the video system, there is a drawback that the control system becomes complicated.

Further, according to the second example, as shown in FIG. 5, it is necessary to provide a control signal generation circuit 72 for controlling the gain control circuit 71 separately from the control signal generation circuits 65 and 66, which makes the control complicated. There is a drawback.

[Means to solve the problem]

The video signal synthesis device of the present invention includes first and second gain control circuits that each receive a plurality of input video signals and perform gain control and synthesis independently of each other; a first switching circuit that switches and outputs the output, and a second switching circuit that outputs two outputs obtained by switching between the two outputs of the first switching circuit and the outputs of the first and second gain control circuits. a first phase that adjusts the two outputs of the first switching circuit so that the phases of the two outputs of the first switching circuit match with the outputs of the first and second gain control circuits input to the second switching circuit; an adjustment circuit, first and second control signal generation circuits that control gains of the first and second gain control circuits, and switching outputs of either of the outputs of the first and second control signal generation circuits; a second phase adjustment circuit that adjusts the phase of the output of the third switching circuit to match the phase of the output of the second switching circuit; and the second switching circuit. Receive the two outputs of
a third gain adjustment circuit that performs gain control on the output of the second phase adjustment circuit and outputs a composite signal;
a fourth switching circuit that switches between the output of the gain control circuit and the output of the third gain control circuit, and the phase of the outputs of the first and second gain control circuits that are input to the fourth switching circuit; and third and fourth phase adjustment circuits that adjust the phase adjustment circuit to match the phase of the output of the third gain control circuit.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a connection system diagram in the operation of the embodiment of FIG.

The configuration of the embodiment shown in FIG. 1 is as follows: gain control circuits 5 and 6 as first and second gain control circuits;
02, phase adjustment circuits 9 and 10 that constitute the first phase adjustment circuit 103, control signal generation circuits 7 and 8 as the first and second control signal generation circuits, and the third A switching circuit 11 as a switching circuit, a phase adjustment circuit 12 as a second phase adjustment circuit, a gain control circuit 17 as a third gain control circuit, switching circuits 18 and 19 forming a fourth switching circuit, and a third switching circuit. and phase adjustment circuits 15 and 16 as a fourth phase adjustment circuit.

Next, the operation of the embodiment of the present invention will be explained.

The input video signal is supplied to the gain control circuit 5 as a first gain control circuit and the switching circuits 3 and 4 forming the first switching circuit 101 through input terminals 1-1, 1-2. Further, the input video signal from the input terminal 2-1.2-2 is input to a gain control circuit 6 as a second gain control circuit and a switching circuit 3.
．． 4.

The outputs of the switching circuits 3 and 4 are each supplied to a switching circuit 13.14 forming a second switching circuit 102 via a phase adjustment circuit 9.10 forming a first phase adjustment circuit 103.

The gain control circuits 5 and 6 are controlled by the control signal generation circuits 7 and 8 of the first and second control signal generation circuits, respectively, and transmit the output signals to the phase adjustment circuits 15 and 16 of the third and fourth phase adjustment circuits. and to the switching circuits 13 and 14.

The output signals of the switching circuits 13 and 14 are supplied to a gain control circuit 17, which is a third gain control circuit.

The switching circuit 11, which is a third switching circuit, switches the control signals output from the control signal generation circuits 7 and 8, which are the first and second control signal generation circuits, and switches the control signals output from the control signal generation circuits 7 and 8, which are the first and second control signal generation circuits, to the phase adjustment circuit of the second phase adjustment circuit. 12. The gain control circuit 17 is controlled by this output.

The switching circuits 18 and 19 constituting the fourth switching circuit 104 switch the output signals of the phase adjustment circuits 15 and 16 and the gain control circuit 17 to the first and second output terminals 20 and 21, respectively. Second
output as an output video signal.

With this video system, as shown in FIG.
．． Continue to connect 17 to input terminal 1-1゜1-2.2-2
When combining the input video signals of and outputting to the output terminal 21,
Focusing on the input video signal of the input terminal 1-1, it only needs to go through one stage of the switching circuit 13, thereby simplifying the video system. This makes it possible to prevent the deterioration of the video characteristics of the output signal, and also allows systems other than those shown in FIG. 2 to be realized using a simple control method. Since the control signal for controlling the gain control circuit 17 is obtained by switching the outputs of the control signal generation circuits 7 and 8, the control becomes easier.

In this embodiment, the gain control circuits 5 and 6 handle two signals, but it is clear that similar effects can be obtained even if the gain control circuit handles three or more signals.

〔Effect of the invention〕

As explained above, the present invention provides a first (second) input video signal in which the gain is controlled by the first (second) control signal generation circuit in the first (second) gain control circuit for two systems of input video signals.
) system signal and the second (first) system signal whose phase has been adjusted by the phase adjustment circuit via the switching circuit, are transferred to the newly added third gain control circuit. 1st
) By performing gain control using the control signal generation circuit, the video system is shortened, deterioration of characteristics is significantly improved, and the control method is extremely simple.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the video signal synthesis device of the present invention, FIG. 2 is a connection system diagram of the operation of the video signal synthesis device of FIG. 1, and FIG. 3 is a diagram of a conventional video signal synthesis device. FIG. 4 is a block diagram of the first example, FIG. 4 is a connection system diagram of the operation of the video signal synthesis device of FIG. 3, and FIG. 5 is a block diagram of a second example of the conventional video signal synthesis device. 1-1.1-2.2-1.2-2...input terminal, 3.
4... (first) switching circuit, 5... (first) gain adjustment circuit, 6... (second) gain adjustment circuit, 7...
(first) control signal generation circuit, 8... (second) control signal generation circuit, 9, 1o... (first) phase adjustment circuit, 11... (third) switching circuit , 12... (second) phase adjustment circuit, 13.14... (second) switching circuit, 15... (third) phase adjustment circuit, 16... (fourth) Phase adjustment circuit, 17... (third) gain control circuit, 18.19... (fourth) switching circuit, 20, 21
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Claims (1)

[Claims] first and second gain control circuits that each receive a plurality of input video signals and perform gain control and synthesis independently of each other; and a first switching circuit that receives the plurality of input video signals and switches and outputs two of them. and a second switching circuit that outputs two outputs obtained by switching the two outputs of the first switching circuit and the outputs of the first and second gain control circuits, and this second switching circuit. a first phase adjustment circuit that adjusts the phases of the two outputs of the first switching circuit to match the outputs of the first and second gain control circuits that are input to the first and second gain control circuits; first and second control signal generation circuits that control the gain of the second gain control circuit; a third switching circuit that switches between outputs of the first and second control signal generation circuits; a second phase adjustment circuit that adjusts the phase of the output of the third switching circuit to match the phase of the output of the second switching circuit; and a second phase adjustment circuit that receives two outputs from the second switching circuit; a third gain adjustment circuit that performs gain control on the output of the second phase adjustment circuit and outputs the composite output, and outputs of the first and second gain control circuits and the output of the third gain control circuit. A fourth switching circuit that switches between each, and adjusting the phase of the output of the first and second gain control circuits that are input to the fourth switching circuit to match the phase of the output of the third gain control circuit. A video signal synthesizing device, comprising third and fourth phase adjustment circuits, and obtaining a composite output of the plurality of input video signals from the fourth switching circuit.