| 摘要 |
PURPOSE:To make the use of an exclusive character driving circuit unnecessary, to simplify the constitution of a circuit, and to execute character insertion by a small number of circuit elements by providing an inversion amplifier, etc., by a transistor TR in a character insertion circuit. CONSTITUTION:Chrominance signals from output terminals 2R-2B of a color difference signal output circuit part 1 are added to driving NPN transistors TRs 4R-4B through resistances 3R-3B. Emitters of TRs 4R-4B are connected in common, and connected to the emitter of a PNP TR9 which is driven by a luminance signal from a luminance signal output circuit part 11. Respective output terminals 7R-7B are connected to collectors of the TRs 4R-4B, and the output is supplied to a CRT. The character signal from a character signal input terminal 21 is waveform-shaped by a waveform shaping circuit 22, and added to respective inversion amplifiers 24 and 25. Respective outputs whose lower limits are set by the amplifiers 24 and 25 are added to diodes 28G and 28R-28Y through PNP type TRs 26 and 27, the outputs are added to the TRs 4R-4B, and the TR9, and the simple circuit constitution is obtained. |
