| 摘要 |
PURPOSE:To turn the chrominance signal component of a signal supplied to an infrared light emitting diode to a low frequency not to be affected by the frequency characteristic of the infrared light emitting diode. CONSTITUTION:A video signal a12 is separated into a luminance signal a2C and a chrominance signal a2Y by a Y/C separator circuit 14, and the luminance signal a2Y is FM modulated with a carrier signal c2 at 10MHz by an FM modulation circuit 15, a chrominance signal d2 and an FM audio signal f2 are added by an adder 16, the resultant signal is amplified by an amplifier 18 and thus turned to a composite signal h2. The composite signal h2 has a chrominance signal component for which the frequency of the carrier signal is 2MHz, chrominance signal component for which the frequency of the carrier signal is 3.58MHz, and luminance signal component having the band of 3MHz before and behind 10MHz as a center. Since such a composite signal g2 is amplified by the amplifier and supplied to an infrared light emitting diode 19, the chrominance signal component of the composite signal h2 supplied to the infrared light emitting diode 19 can be turned to the low frequency not to be affected by the frequency characteristic of the infrared light emitting diode 19. |
