| 摘要 |
An infrared remote control receiver 20 a includes a carrier detection circuit 12 a. The carrier detection circuit 12 a includes: a comparator 6 a for comparing an output signal from a BPF 5 with a threshold voltage Vth 1 which is a noise detection level; a comparator 6 c for comparing the output signal from the BPF 5 with a threshold voltage Vth 3 larger than the threshold voltage Vth 1 , the threshold voltage Vth 3 being a first carrier detection level; and a logic circuit 8 for (i) controlling, based on the output signal D 1 from the comparator 6 a, the gain of an amplifier 4 so that an output signal D 1 from the comparator 6 a is not output. An output signal D 3 from the comparator 6 c is output as a carrier. Thus, it is possible to restrain malfunctions attributed to disturbance light noise.
|
