JPH04245784A - Image mixing/amplifying device - Google Patents

Abstract

PURPOSE:To obtain an image mixing/amplifying device capable of easily adjusting the phase of a video output signal. CONSTITUTION:The delay time of a video signal in a delay circuit 4 is determined by a phase difference between a writing phase pulse and a reading phase pulse respectively outputted from the 2nd and 3rd pulse generating circuits 2, 3. The reading phase pulse is inputted also to a key signal generating circuit 5 and a synchronizing signal generating circuit 7 and the phases of a key signal and a substituting synchronizing signal are determined by the reading phase pulse. The phase of the writing phase pulse is determined by a writing phase adjusting data signal W and a pulse signal outputted from the 1st pulse generating circuit 1. On the other hand, the phase of the reading phase pulse is determined by a reading phase adjusting data signal R and a pulse signal outputted from the 1st pulse generating circuit 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video mixing and amplifying device for television that mixes and outputs a plurality of videos.

0002

2. Description of the Related Art FIG. 2 is a block diagram showing a conventional video mixing amplification device.

The pulse generation circuit 9 receives the reference synchronization signal B from the reference synchronization signal input terminal 16 as well as the phase adjustment data signal D1, and generates pulse signals such as horizontal synchronization pulses and vertical synchronization pulses. Key signal generation circuit 1
1 is a phase adjustment data signal D2 and a pulse generation circuit 9
and generates a key signal based on these signals. This key signal is input to the video mixing amplification circuit 6. The delay circuit 10 receives a plurality of video signals A1 and A2 from a plurality of (two in the figure) video signal input terminals 15a and 15b as well as a phase adjustment data signal D3, and outputs the video signals A1 and A2 for a predetermined period of time. After being delayed by the same amount, these delayed video signals are outputted to the video mixing amplification circuit 6. The video mixing amplification circuit 6 mixes these delayed video signals based on the key signal inputted from the key signal generation circuit 11, and outputs the mixed video signal as a composite video signal.

The synchronizing signal generating circuit 12 also receives the phase adjustment data signal D4 and the pulse signal from the pulse generating circuit 9, and generates a replacement synchronizing signal based on these signals. The synchronization signal replacement circuit 8 inputs the composite video signal from the video mixing amplification circuit 6, replaces the synchronization signal included in the composite video signal with the replacement synchronization signal from the synchronization signal generation circuit 12, and converts the video It is output as a video output signal C from the signal output terminal 17.

[0005]

However, the above-mentioned conventional video mixing amplification device has a complicated circuit configuration and has many points for phase adjustment (i.e., phase adjustment data signals D1, D2, D3, D4). is input 4
Therefore, when it becomes necessary to change the phase of the video output signal C in a video system that includes this video mixing amplification device, it is necessary to adjust all of these phase adjustment locations, which is cumbersome. There is a problem.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a video mixing amplification device that allows easy phase adjustment of a video output signal.

[0007]

[Means for Solving the Problems] A video mixing amplification device according to the present invention receives a reference synchronization signal and a synchro phase adjustment data signal and outputs a pulse signal whose phase is determined by the synchro phase adjustment data signal. a second pulse generating circuit that receives the write phase adjustment data signal and the pulse signal and outputs a write phase pulse whose phase is determined by these signals; a third pulse generation circuit which inputs pulse signals and outputs a readout phase pulse whose phase is determined by these signals; and a third pulse generation circuit which inputs a plurality of video signals and calculates the phase difference between the write phase pulse and the readout phase pulse. a delay circuit that delays these video signals by a time based on the signal and outputs it as a delayed video signal; a key signal generation circuit that outputs a key signal whose phase is determined by the readout phase pulse; and a key signal generation circuit that outputs a key signal whose phase is determined by the readout phase pulse; a synchronization signal generation circuit that outputs the determined replacement synchronization signal; a video mixing amplification circuit that mixes the delayed video signal based on the key signal and outputs it as a composite video signal; The apparatus is characterized by comprising a synchronization signal replacement circuit that replaces the synchronization signal with the replacement synchronization signal.

[0008]

[Operation] In the present invention, the delay time of the video signal in the delay circuit is determined by the phase difference between the write phase pulse output from the second pulse generation circuit and the read phase pulse output from the third pulse generation circuit. Determined based on Furthermore, the phases of the key signal output from the key signal generation circuit and the replacement synchronization signal output from the synchronization signal generation circuit are determined by the readout phase pulse. Furthermore, the phase of the write phase pulse is determined based on a pulse signal and a write phase adjustment data signal output from the first pulse generation circuit, and the phase of the read phase pulse is determined based on the pulse signal output from the first pulse generation circuit. This is determined based on the pulse signal and readout phase adjustment data signal. As a result, in the video mixing amplification device according to the present invention, by adjusting the write phase adjustment data signal and the read phase adjustment data signal to change the phase difference between the write phase pulse and the read phase pulse,
The phase of the video output signal can be adjusted.

In this case, for example, if the write phase adjustment data signal is determined to be a specific signal, the video delay time in the delay circuit and the phase of the key signal and replacement synchronization signal can be adjusted just by adjusting the read phase adjustment data signal. The phase adjustment of the video output signal is completed.

Therefore, in the video mixing amplification device according to the present invention, it is extremely easy to adjust the phase of the video output signal.

[0011]

Embodiments Next, embodiments of the present invention will be described with reference to the accompanying drawings.

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

The first pulse generation circuit 1 inputs a reference synchronization signal B from a reference synchronization signal input terminal 16, synchronously separates this reference synchronization signal B, and generates pulse signals such as horizontal synchronization pulses and vertical synchronization pulses. Output. In this case, the phase of these pulse signals can be adjusted using the synchro phase adjustment data signal S.

The second pulse generating circuit 2 receives the pulse signal from the first pulse generating circuit 1 as well as the write phase adjustment data signal W, and outputs a write phase pulse. In this case, the phase of the write phase pulse is determined by the write phase adjustment data signal W and the pulse signal from the first pulse generation circuit 1. Therefore, the phase of this write phase pulse can also be changed by the synchro phase adjustment data signal S.

The third pulse generating circuit 3 receives the pulse signal from the first pulse generating circuit 1 as well as the read phase adjustment data signal R, and outputs a read phase pulse. In this case, the phase of the readout phase pulse is determined by the readout phase adjustment data signal R and the pulse signal from the first pulse generation circuit 1. Therefore, the phase of this readout phase pulse can also be changed by the synchro phase adjustment data signal S.

The delay circuit 4 receives a plurality of video signals A1 from a plurality of (two in the figure) video signal input terminals 15a and 15b.
, A2 are input, these video signals are delayed by a predetermined time, and output as delayed video signals. The delay time at this time is determined by the phase difference between the write phase pulse output from the second pulse generation circuit 2 and the read phase pulse output from the third pulse generation circuit 3.

The key signal generating circuit 5 receives the read phase pulse outputted from the third pulse generating circuit 3 and generates a key signal whose phase is determined by the read phase pulse. Therefore, the phase of this key signal changes depending on the synchro phase adjustment data signal S and the readout phase adjustment data signal R.

The synchronization signal generation circuit 7 also receives the readout phase pulse output from the third pulse generation circuit 3, and generates a replacement synchronization signal whose phase is determined by this readout phase pulse. Therefore, the phase of this synchronization signal for replacement also changes depending on the synchro phase adjustment data signal S and the readout phase adjustment data signal R.

The video mixing amplification circuit 6 inputs a plurality of delayed video signals from the delay circuit 4, mixes these delayed video signals based on the key signal, and outputs the mixed video signal as a composite video signal.

The synchronization signal replacement circuit 8 inputs the composite video signal from the video mixing amplifier circuit 6 and replaces the synchronization signal included in this composite video signal with the replacement synchronization signal output from the synchronization signal generation circuit 7. Thereafter, this composite video signal is outputted to the video output terminal 17 as a video output signal C.

In this embodiment, the phases of the write phase pulse, the read phase pulse, the key signal, and the synchronization signal for replacement are managed by the synchro phase adjustment data signal S, and the relative phase of the read phase pulse with respect to the write phase pulse is adjusted. This makes it possible to adjust the delay time of the video signal in the delay circuit 4 and the phases of the key signal and replacement synchronization signal. Therefore, if it is necessary to change the phase of the video output signal C in the video system, this can be done by adjusting only the readout phase adjustment data signal R, for example.

[0022]

As explained above, according to the present invention, the phase of the write phase pulse is determined by the write phase adjustment data signal and the pulse signal, and the phase of the read phase pulse is determined by the read phase adjustment data signal and the pulse signal. The delay time of the video signal in the delay circuit is determined by the phase difference between the read pulse and the write pulse, and the phases of the key signal and replacement synchronization signal are determined by the read phase pulse. For example, the phase of the output signal can be adjusted only by adjusting the read phase adjustment data signal. Therefore, the video mixing and amplifying device according to the present invention has the advantage that the phase of the video output signal can be adjusted much more easily than in the prior art.

[Brief explanation of the drawing]

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

FIG. 2 is a block diagram showing a conventional video mixing amplification device.

[Explanation of symbols]

1, 2, 3, 9; Pulse generation circuit 4,10; Delay circuit 5, 11; Key signal generation circuit 6; Video mixing amplification circuit 7, 12; Synchronization signal generation circuit 8; Synchronous signal replacement circuit 15a, 15b; Video signal input terminal 16; Reference synchronization signal input terminal 17; Video signal output terminal

Claims (2)

[Claims] 1. A first pulse generating circuit that receives a reference synchronization signal and a synchronized phase adjustment data signal and outputs a pulse signal whose phase is determined by the synchronized phase adjustment data signal; a second pulse generation circuit which receives a pulse signal and outputs a write phase pulse whose phase is determined by these signals; and a second pulse generation circuit which receives a read phase adjustment data signal and the pulse signal and whose phase is determined by these signals. a third pulse generation circuit that outputs a readout phase pulse;
a delay circuit that receives a plurality of video signals, delays these video signals by a time based on a phase difference between the write phase pulse and the read phase pulse, and outputs the delayed video signal; and a delay circuit whose phase is determined by the read phase pulse. a key signal generation circuit that outputs a key signal to be read, a synchronization signal generation circuit that outputs a replacement synchronization signal whose phase is determined by the readout phase pulse, and a synchronization signal generation circuit that mixes the delayed video signal based on the key signal. A video mixing amplification device comprising: a video mixing amplification circuit that outputs a composite video signal; and a synchronization signal change circuit that replaces a synchronization signal included in the composite video signal with the replacement synchronization signal. 2. The video mixing amplification device according to claim 1, wherein the write phase adjustment data signal is a constant signal, and the read phase adjustment data signal is an adjustable signal.