US4942393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Passive keyless entry system
Assignee: Eaton Corp
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Filing: 1988-05-27
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Granted: 1990-07-17
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Expires: 2008-05-27
Abstract
Abstract A passive keyless entry system is disclosed that is specifically adapted for use with automotive vehicles. The system is designed to automatically unlock the vehicle as the operator approaches the vehicle. The system is further designed to automatically lock the vehicle as the operator, carrying the beacon, moves away from the vehicle. The system includes a portable beacon that is carried by the operator, a receiver/controller located in the vehicle, and an antenna connected to the receiver/controller for receiving the encoded transmission from the beacon. The beacon includes a motion sensor to conserve battery life when the beacon is stationary. Transmission between the beacon and the receiver/controller is characterized by a magnetically coupled radio frequency signal embodying differential phase encoded data with error correction coding of the data to enhance noise immunity and signal discrimination.
Inventors
- 👤 Thomas J. Waraksa
- 👤 Keith D. Fraley
- 👤 Richard E. Kiefer
- 👤 Daniel G. Douglas
- 👤 Lee H. Gilbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:17
CPC Classifications
G; G07; G07C; G07C9/00; G07C9/00174; G07C9/00182; G07C2009/0023; G07C2009/00238; G07C2009/00246; G07C2009/00753; G07C2009/00769; G07C2009/00793; G07C9/00944; G07C2009/0096; G07C2209/00; G07C2209/60; G07C2209/63; H; H04; H04L; H04L7/00; H04L7/04; H04L7/041
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
118 words
A keyless entry system for a vehicle having an electric door lock mechanism, and including: a portable beacon adapted to be carried by the operator of the vehicle and comprising transmitter means for transmitting a coded beacon signal; and receiver means associated with the vehicle and including antenna means for receiving said beacon signal when said beacon is within a predetermined range and controller means for decoding said beacon signal and activating a predetermined function associated with the vehicle in response thereto, said controller means being further adapted to automatically activate said electric door lock mechanism to lock the doors of the vehicle after the operator leaves the vehicle and carries said beacon out of said predetermined range.
Claim 2
Dependent Claim
118 words
A keyless entry system for a vehicle having an electric door lock mechanism, and including: a portable beacon adapted to be carried by the operator of the vehicle and comprising transmitter means for transmitting a coded beacon signal; and receiver means associated with the vehicle and including antenna means for receiving said beacon signal when said beacon is within a predetermined range and controller means for decoding said beacon signal and activating a predetermined function associated with the vehicle in response thereto, said controller means being further adapted to automatically activate said electric door lock mechanism to lock the doors of the vehicle after the operator leaves the vehicle and carries said beacon out of said predetermined range.
Claim 3
Dependent Claim
27 words
The keyless entry system of claim 1 further including means for producing a first output signal when the ignition key of the vehicle is in the ignition.
Claim 4
Dependent Claim
51 words
The keyless entry system of claim 2 wherein said controller means is adapted to automatically activate said electric door lock mechanism to lock the doors of the vehicle after the operator leaves the vehicle and carries said beacon away from the vehicle only if said first output signal is not present.
Claim 5
Dependent Claim
44 words
The keyless entry system of claim 3 wherein said controller means is adapted to automatically activate said door lock mechanism to lock the doors of the vehicle a predetermined period of time after said beacon signal is out of range of said antenna means.
Claim 6
Dependent Claim
45 words
The keyless entry system of claim 1 wherein said beacon further includes a portable power source, motion sensing means for sensing physical motion of said beacon, and circuit means responsive to said motion sensing means for activating said transmitter means to transmit said beacon signal.
Claim 7
Dependent Claim
31 words
The keyless entry system of claim 5 wherein the circuitry in said beacon has a current drain on said portable power source in the microamp range when said beacon is stationary.
Claim 8
Dependent Claim
24 words
The keyless entry system of claim 3 further including means for producing a second output signal when the doors of the vehicle are open.
Claim 9
Dependent Claim
54 words
The keyless entry system of claim 7 wherein said controller means is adapted to automatically activate said electric door lock mechanism to lock the doors of the vehicle after the operator leaves the vehicle and carries said beacon away from the vehicle only if both said first and second output signals are not present.
References Cited (Backward Citations)
US4477874A
Cited
US4450545A
Cited
US4428024A
Cited
US4455588A
Cited
US4488056A
Cited
US4482895A
Cited
US4684943A
Cited
US4607312A
Cited
US4580136A
Cited
US4595902A
Cited
US4596985A
Cited
US4602256A
Cited
US4602255A
Cited
US4631736A
Cited
US4719460A
Cited
US4737784A
Cited
US4670746A
Cited
US4672375A
Cited
US4688036A
Cited
US4686529A
Cited
US4730188A
Cited
US4663626A
Cited
US4700186A
Cited
US4723121A
Cited
US4835533A
Cited
US4733215A
Cited
US4835531A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |