| 摘要 |
<p>PURPOSE:To prevent a transmission signal from a remote key from becoming not receptible by other communication radio wave signal. CONSTITUTION:A transmission circuit of a remote key is provided with two oscillation circuits 22, 23 able to provide outputs of carriers whose frequencies f1, f2 are in the relation of a non-integer multiple and the carrier is alternately modulated by an ID code stored in a key side memory 19 depending on the operation of an operation switch 4 and the modulated signal is outputted as a radio wave signal. A receiver uses two RF circuits to demodulate signals of corresponding carriers and to detect the ID code, a collation circuit collates the ID code with an ID code stored in a vehicle side memory and provides an output of a matching detection signal when they are matched. Even when other communication radio signal is in existence, since no interference onto both the carriers takes place, the reception collation is surely implemented.</p> |
