To receive data of a tire air pressure transmitted from a sensor transmitter on the receiver side without generating electric wave interference, even if an electric wave for power charge and an electric wave of the data transmitted from the sensor transmitter have the same frequency band.
The electric wave for power charge is transmitted from a car body side antenna as long as a Tmax time. Power charge is performed in the sensor transmitter by the electric wave for power charge, and a charge voltage of a charge part is heightened gradually. When the charge voltage of the charge part reaches a sensor driving start voltage, the sensor transmitter is started, and transmits the data of the tire air pressure after elapse of the Tmax time. Hereby, since transmission of the electric wave for power charge is stopped without fail when the data of the tire air pressure is transmitted by the sensor transmitter, interference between the electric wave for power charge and the electric wave transmitted from the sensor transmitter can be avoided.
SAITO HIDEKI
| JP2004133911A | 2004-04-30 | |||
| JPH0513802U | 1993-02-23 | |||
| JP2000252855A | 2000-09-14 | |||
| JPH1019710A | 1998-01-23 | |||
| JP2004314893A | 2004-11-11 |
Takahiro Miura
Fumihiro Mizuno
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