Composite video signal generator
AssigneeNEC Corporation
InventorTakafumi Esaki
Life of this patent
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Abstract
Disclosed is a composite video generator comprising a color signal generating means, a color selecting means and an output means, and further being provided with a color change detecting means and a low amplitude color signal generating means. The composite video signal generator which combines a composite video input signal with a color signal as a character signal in accordance with a character data presence/absence signal to output the resultant signal as a composite video output signal. The composite video signal generator detects changes in the color signal and character data presence/absence signal and lowers the amplitude of the color signal at each change point, thereby suppressing the occurrence of a dot disturbance and color mixture.
Claims3
A composite video signal generator comprising:
- a color signal generating means for generating color signals of a pulse waveform each having predetermined high and low voltages in association with an individual color;
- a color selecting means for selectively outputting the color signals output from the color signal generating means in accordance with an input character color signal;
- and
- an output means for combining a composite video input signal with the color signal sent from the color selecting means in accordance with an input character data presence/absence signal to output a resultant signal as a composite video output signal;
- said generator further comprising
- a color change detecting means for detecting changes in the input character color signal and character data presence/absence signal to output a color change signal;
- and
- a low amplitude color signal generating means, provided in the color signal generating means, for generating a color signal of a pulse waveform having a lower amplitude than an amplitude determined by the high and low level voltages in accordance with the color change signal output from the color change detecting means.
Dependencies are inferred from the claim text.