Patent US6018641A successfully refreshed from Google Patents.
US6018641A
Expired / Lapsed
US
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Radio IC card system
Assignee: Individual
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Filing: 1997-04-10
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Granted: 2000-01-25
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Expires: 2017-04-10
Abstract
Abstract A radio IC card system includes an IC card and a toll collector. When an automobile with the IC card passes by a tollgate, the toll collector installed in the tollgate transmits a first radio signal which is spread modulated using a pseudorandom noise (PN) code from an antenna. The first radio signal is received by the antenna of the IC card and is transmitted to a surface acoustic wave (SAW) correlator. The SAW correlator extracts a PN code included in the received signal, and outputs a peak signal. An accumulation circuit accumulates the peak signal. A threshold discharger is activated to switch on a relay switch when the output voltage of the accumulation circuit exceeds a constant value. Thereby, the voltage of a battery is supplied to a data communication unit. Then, the identification code of the IC card and a record of tollgates by which the automobile has passed are transmitted via radio signal to the toll collector.
Inventors
- 👤 Kazuo Tsubouchi
- 👤 Jun Hozumi
- 👤 Toshiyuki Azuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:27
CPC Classifications
G; G06; G06K; G06K17/00; G07; G07B; G07B15/00; G07B15/06; G07B15/063; G06K7/00; G06K7/0008; G08; G08G; G08G1/00; G08G1/01; G08G1/017
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
191 words
An IC card for use with a radio data transmitter/receiver device that transmits a first signal comprising a predetermined pattern and a second radio signal comprising predetermined carrier-modulated data from a transmitting antenna, the IC card comprising: a radio switching means, activated by the predetermined pattern in said first radio signal, comprising: a receiving antenna for receiving said first radio signal; a surface acoustic wave (SAW) matched filter for extracting said predetermined pattern from said received first radio signal; an accumulation circuit for generating an output power accumulated from said SAW matched filter; and a switching circuit, activated when said output power from said accumulation circuit exceeds a predetermined threshold value; and a data communication unit for receiving said second radio signal from and transmitting a third radio signal comprising data to said transmitter/receiver device, for processing said data, and for transmitting a control signal to said radio switching means after terminating transmission or reception and processing of said data; wherein said data communications unit is connected to a battery via said switching circuit for supplying power to said data communication unit in response to activation of said radio switching means.
Claim 2
Dependent Claim
191 words
An IC card for use with a radio data transmitter/receiver device that transmits a first signal comprising a predetermined pattern and a second radio signal comprising predetermined carrier-modulated data from a transmitting antenna, the IC card comprising: a radio switching means, activated by the predetermined pattern in said first radio signal, comprising: a receiving antenna for receiving said first radio signal; a surface acoustic wave (SAW) matched filter for extracting said predetermined pattern from said received first radio signal; an accumulation circuit for generating an output power accumulated from said SAW matched filter; and a switching circuit, activated when said output power from said accumulation circuit exceeds a predetermined threshold value; and a data communication unit for receiving said second radio signal from and transmitting a third radio signal comprising data to said transmitter/receiver device, for processing said data, and for transmitting a control signal to said radio switching means after terminating transmission or reception and processing of said data; wherein said data communications unit is connected to a battery via said switching circuit for supplying power to said data communication unit in response to activation of said radio switching means.
Claim 3
Dependent Claim
40 words
An IC card according to claim 1, wherein said SAW matched filter comprises an Al 2 O 3 substrate, an AlN film formed on said Al 2 O 3 substrate, and an Al tapping pattern formed on said AlN film.
Claim 4
Dependent Claim
259 words
An IC card for use with a radio data transmitter/receiver device that transmits a first signal comprising a predetermined pattern and a second radio signal, the IC card comprising: a radio switching means, activated by the predetermined pattern in said first radio signal, comprising: a receiving antenna for receiving said first radio signal; a surface acoustic wave (SAW) matched filter for extracting said predetermined pattern from said received first radio signal; an accumulation circuit for generating an output power accumulated from said SAW matched filter; and a switching circuit, activated when said output power from said accumulation circuit exceeds a predetermined threshold value; a data communication unit for receiving said second radio signal from and transmitting a third radio signal comprising data to said transmitter/receiver device, for processing said data, and for transmitting a control signal to said radio switching means after terminating transmission or reception and processing of said data; wherein said data communications unit is connected to a battery via said switching circuit for supplying power to said data communication unit in response to activation of said radio switching means; switch-activation means for transmitting said first radio signal, said switch-activation means comprising: noise code generating means for generating a pseudorandom noise code; means for generating said first radio signal by modulating a carrier using said noise code; and an antenna for radiating said first radio signal; and transmitter/receiver means for transmitting a second radio signal comprising data and for receiving a third radio signal comprising data from a data communications unit activated by said first radio signal.
Claim 5
Dependent Claim
259 words
An IC card for use with a radio data transmitter/receiver device that transmits a first signal comprising a predetermined pattern and a second radio signal, the IC card comprising: a radio switching means, activated by the predetermined pattern in said first radio signal, comprising: a receiving antenna for receiving said first radio signal; a surface acoustic wave (SAW) matched filter for extracting said predetermined pattern from said received first radio signal; an accumulation circuit for generating an output power accumulated from said SAW matched filter; and a switching circuit, activated when said output power from said accumulation circuit exceeds a predetermined threshold value; a data communication unit for receiving said second radio signal from and transmitting a third radio signal comprising data to said transmitter/receiver device, for processing said data, and for transmitting a control signal to said radio switching means after terminating transmission or reception and processing of said data; wherein said data communications unit is connected to a battery via said switching circuit for supplying power to said data communication unit in response to activation of said radio switching means; switch-activation means for transmitting said first radio signal, said switch-activation means comprising: noise code generating means for generating a pseudorandom noise code; means for generating said first radio signal by modulating a carrier using said noise code; and an antenna for radiating said first radio signal; and transmitter/receiver means for transmitting a second radio signal comprising data and for receiving a third radio signal comprising data from a data communications unit activated by said first radio signal.
Claim 6
Dependent Claim
42 words
A radio IC card system according to claim 3 wherein said SAW matched filter comprises an Al 2 O 3 substrate, an AlN film formed on said Al 2 O 3 substrate, and an Al tapping pattern formed on said AlN film.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-01-24 | 2003-07-26 | 2004-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-24 | 2007-07-26 | 2008-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-24 | 2011-07-26 | 2012-01-25 | $7700.00 | Window Closed / Lapsed |