| 摘要 |
PURPOSE:To prevent a learning remote control identification code from being stored by adding a carrier signal of a different frequency from that of a carrier signal used to modulate an ID code for a predetermined time and sending the resulting signal. CONSTITUTION:An operation circuit 11 of a transmitter T built in a key holder 1 outputs a depression signal to a decoder circuit 12 based on the operation of a depression button 2. In this case, a generating circuit 16 outputs a carrier signal S2 whose frequency is fMA to a modulation circuit 14 for a predetermined time. The circuit 12 reads an ID code S in a memory 13. As soon as the ID code S is outputted to the circuit 14, the generating circuit 15 outputs the carrier signal S1 whose frequency is fM to the circuit 14. Upon the receipt of the ID code S and the signal S1, the circuit 14 applies frequency modulation to the ID code S based on the signal S1 to provide an output to a light emitting circuit 17. The circuit 17 activates a light emitting section 3 based on modulating signals H1, H2 and sends an infrared ray to a receiver R. The receiver R sends a control signal based on a received code S4 and a discrimination code S5. |
