Transponder, interrogator and system thereof

• US 6,791,457 B2
• Filed: 01/03/2002
• Issued: 09/14/2004
• Est. Priority Date: 01/11/2001
• Status: Expired due to Fees

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Shimura, Kazuhiro
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): NGUYEN, HUNG T
• Application Number:
  US10/033,985
• Publication Number:
  US 20020088517A1
• Time in Patent Office: 985 Days
• Field of Search: 340/442, 340/444, 340/447, 340/448, 731/462, 731/468, 200/61.22, 116/34.R
• US Class Current: 340/448
• CPC Class Codes: B60C 23/041 Means for supplying power to the signal- transmitting means on the wheel
• CPC Class Codes: B60C 23/0413 Wireless charging of active radio frequency circuits
• CPC Class Codes: B60C 23/0433 Radio signals
• CPC Class Codes: B60C 23/0479 Communicating with external units being not part of the vehicle, e.g. tools for diagnostic, mobile phones, electronic keys or service stations
• CPC Class Codes: B60C 23/0493 for attachment on the tyre
• CPC Class Codes: H01Q 1/2241 used in or for vehicle tyres
• CPC Class Codes: Y10T 152/10027 with wear indicating feature

Abstract

A data transmission-reception unit which operates by means of energy of a received electromagnetic wave and serves as a main circuit, is provided with a sensor circuit as an additional circuit, and a transponder having a sensor power circuit for supplying electric power only to the sensor circuit is constituted. From a sensor charging circuit of an interrogator, an electromagnetic wave of a lower frequency different from a frequency of electromagnetic wave for data communication is radiated, or loop coil-shaped charging antennas are electromagnetic-coupled to thereby charge a capacitor for the sensor power circuit. Thereby, a secondary battery and the capacitor such as a large scale capacitor can be easily charged from an outside, and further, a power consumption for the capacitor can be restrained.

Claims

1. A transponder for tire having information storage means for gaining access to information within said information storage means at received a predetermined question signal, and for transmitting an answering signal, comprising:

a main circuit including;

first receiving means for receiving an electromagnetic wave of a predetermined first frequency;

first energy converting means for converting energy of the electromagnetic wave received by said first receiving means into electric energy;

a central processing unit for operating by means of electric energy to be outputted from said first energy converting means and for reading, on receipt of said predetermined question signal by said first receiving means, storage information of said information storage means in response to the content of said predetermined question signal to generate an electric signal representing answering information for outputting; and

transmission means for operating by means of electric energy to be outputted from said first energy converting means and for transmitting an answering signal on the basis of an electric signal representing said answering information outputted from said central processing unit;

second receiving means for receiving an electromagnetic wave of a second frequency that is lower than said first frequency;

second energy converting means for converting energy of an electromagnetic wave received by said second receiving means into electric energy;

a capacitor for accumulating electric energy to be outputted from said second energy converting means; and

an additional circuit, in which the electric power consumption of which is larger than that of said main circuit,

wherein as a main power source or an auxiliary power source for operating said additional circuit, electric energy accumulated in said capacitor is used.

2. The transponder according to claim 1, wherein as said additional circuit, there is provided a sensor portion for detecting predetermined physical quantity within a tire to output the detection result as an electric signal, and said central processing unit has means for taking in detection result by said sensor portion to include into said answering information.

3. The transponder according to claim 2, wherein

said electric energy charged in said capacitor is used only to drive said sensor portion.

4. The transponder according to claim 3, wherein there is provided means for carrying current to said sensor portion from said capacitor only for predetermined time until the physical quantity is detected by said sensor portion and said detection result is taken in said central processing unit.

5. The transponder according to claim 2, wherein

said capacitor has charging capacity capable of charging electrical energy sufficient to obtain detection result by said sensor portion at least once.

6. The transponder according to claim 2, wherein

said sensor portion has at least one of a temperature sensor and a pneumatic pressure sensor.

7. The transponder according to claim 1, wherein

said capacitor is constituted by a secondary battery.

8. The transponder according to claim 1, wherein

said capacitor is constituted by a large scale capacitor.

9. The transponder according to claim 1, wherein

said first frequency is set to a frequency above a short wave region, and said second frequency is set to a frequency below a medium wave region.

10. The transponder according to claim 9, wherein

said second frequency is set to a frequency below 200 kHz.

11. The transponder according to claim 1, wherein

said first frequency is set to a frequency different from frequencies equal to the integer multiple of said second frequency.

12. The transponder according to claim 1, wherein there are provided means for detecting whether or not it is necessary to charge said capacitor, and means for transmitting said answering signal including a signal for requesting charging when charging is required on the basis of said detection result.

13. The transponder according to claim 1, wherein as

an antenna for receiving an electromagnetic wave of said second frequency, said transponder has a loop coil antenna.

14. A transponder system having a transponder fitted to a tire for a vehicle, for transmitting an answering signal on receipt of a question signal, and an interrogator for transmitting said question signal to said transponder and receiving said answering signal from said transponder,

wherein as said transponder, a transponder according to any one of claims 1 to 13 is used,

there is provided with energy supplying means for radiating an electromagnetic wave of said second frequency from an antenna,

said antenna is provided in at least one of a station and a parking lot for said vehicle, and

said energy supplying means has means for radiating an electromagnetic wave to said transponder only when a vehicle provided with said transponder is present in the station or parking lot of said vehicle.

15. The transponder system according to claim 14, wherein only when a signal for requesting supply of energy through an electromagnetic wave of said second frequency is included in said answering signal received by said interrogator, there is provided driving control means for driving said energy supplying means.

16. The transponder system according to claim 14, wherein said transponder system is provided with means for detecting existence of said transponder within an area in which energy can be supplied by said energy supplying means, and driving control means for driving said energy supplying means when there exists said transponder within said area on the basis of said detection result.

17. The transponder system according to claim 14, wherein said transponder system has a loop coil antenna as an antenna through which an electromagnetic wave of the second frequency of said energy supplying means is radiated, and said loop coil antenna and a loop coil antenna for receiving an electromagnetic wave of said second frequency in said transponder are electromagnetic-coupled to thereby supply energy.

18. An interrogator for transmitting a question signal to a transponder and receiving an answering signal transmitted from said transponder, comprising:

data transmission-reception unit including;

a transmission-reception antenna;

question signal transmission means for transmitting through the transmission-reception antenna a question signal to said transponder through an electromagnetic wave of a first frequency; and

receiving means for receiving through the transmission-reception antenna an answering signal transmitted from said transponder correspondingly to said question signal; and

sensor charging circuit including;

a charging antenna;

energy supplying means for transmitting through the charging antenna an electromagnetic wave of a second frequency different from said first frequency in order to supply electric energy to said transponder; and

driving control means for driving said energy supplying means only when a signal for requesting supply of energy through an electromagnetic wave of said second frequency is included in said answering signal.

19. The interrogator according to claim 18, wherein said second frequency is set to a lower frequency than said first frequency.

20. The interrogator according to claim 19, wherein

said first frequency is set to a frequency above a short wave region, and said second frequency is set to a frequency below a medium wave region.

21. The interrogator according to claim 20, wherein

said second frequency is set to a frequency below 200 kHz.

22. The interrogator according to claim 18, wherein

said first frequency is set to a frequency different from frequencies equal to the integer multiple of said second frequency.

23. The interrogator according to claim 18, wherein

a casing in which each of said question signal transmission means, said receiving means and said energy supplying means is housed has portable size and shape.

24. The interrogator according to claim 18, further comprising a loop coil antenna as an antenna for radiating an electromagnetic wave of said second frequency.

25. An interrogator for transmitting a question signal to a transponder and receiving an answering signal transmitted from said transponder, comprising:

data transmission-reception unit including;

a transmission-reception antenna;

question signal transmission means for transmitting through the transmission-reception antenna a question signal to said transponder through an electromagnetic wave of a first frequency; and

receiving means for receiving through the transmission-reception antenna an answering signal transmitted from said transponder correspondingly to said question signal; and

sensor charging circuit including;

a charging antenna; and

energy supplying means for transmitting through the charging antenna an electromagnetic wave of a second frequency different from said first frequency in order to supply electric energy to said transponder, wherein

said interrogator is provided with means for detecting existence of said transponder within an area in which energy can be supplied by said energy supplying means, and driving control means for driving said energy supplying means when there exists said transponder within said area on the basis of said detection result.