| 摘要 |
PURPOSE: A PC-TV signal conversion circuit is provided to be capable of easily verifying text signals to the recognition error of image information presented in TV displaying by recovering a portion of PC signals disappeared due to the difference between TV scan lines and PC scan lines. CONSTITUTION: Analog RGB PC signals based on a VGA mode are input to a VGA input part(11). An A/D converter(11) converts analog PC signals input to the VGA input part(11) into digital signals. An even/odd line determinater(13) determines the even or odd of input lines after detecting the synchronous of the analog PC signals. A switching part(14) is switched to separate the converted analog PC signals into the even or odd lines. Even/odd line memories(15,16) store the separated even or odd line PC signals and then convert the signals into a wide mode. A black level detector(17) detects text signals of black lines which aren't displayed from the converted even line PC signals. A horizontal line delay part(18) delays the text signals of the detected black lines by a horizontal one period. A data adder(19) adds the delayed text signals with the converted odd line PC signals. A D/A converter(20) converts the added signals into analog signals.
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