Transponder startup control method and interrogator for tire pressure monitoring system
First Claim
1. A startup control method for a passive transponder adapted to be started up by receiving an interrogation signal and to return a requested response signal, said startup control method comprising the steps of:
- judging presence or absence of a return of said response signal while monotonically increasing transmission power of said interrogation signal from an initial value by an amount which is made smaller stepwise every time presence of said return is judged; and
maintaining said transmission power, after presence of said return is judged, at the value of said transmission power as of the time when presence of said return was judged.
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Accused Products
Abstract
A passive transponder is started up by receiving an interrogation signal and returning a requested response signal. The startup is controlled by an interrogator using a startup control method by judging presence or absence of a return of the response signal while monotonically increasing transmission power of the interrogation signal from an initial value by an amount which is made smaller stepwise every time presence of the return is judged and maintaining the transmission power, after presence of the return is judged, at its value as of the time when presence of the return was judged.
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Citations
11 Claims
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1. A startup control method for a passive transponder adapted to be started up by receiving an interrogation signal and to return a requested response signal, said startup control method comprising the steps of:
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judging presence or absence of a return of said response signal while monotonically increasing transmission power of said interrogation signal from an initial value by an amount which is made smaller stepwise every time presence of said return is judged; and
maintaining said transmission power, after presence of said return is judged, at the value of said transmission power as of the time when presence of said return was judged. - View Dependent Claims (2, 3, 4, 5)
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6. An interrogator for a tire pressure monitoring system that is used in pair with a passive transponder adapted to be started up by receiving an interrogation signal and to return a response signal that is requested and at least includes tire pressure data, said interrogator comprising:
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a judging part that judges presence or absence of a return of said response signal while monotonically increasing transmission power of said interrogation signal from an initial value by an amount which is made smaller stepwise every time presence of said return is judged; and
a maintaining part that maintains said transmission power, after presence of said return is judged, at the value of said transmission power as of the time when presence of said return was judged by said judging part;
- View Dependent Claims (7, 8, 9, 10, 11)
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Specification