EP0139059A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements in or relating to communication links and locking systems
Assignee: Individual
•
Filing: 1983-10-26
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Granted: —
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Expires: 2003-10-26
Abstract
Abstract A locking system comprises a transmitter 1 which transmits a predetermined code by non-contact means, such as infrared waves. A receiver 2 receives the codes and provides an access-permitting signal, for instance to a vehicle door lock, when a received code is identified as the predetermined code.
Inventors
- 👤 John Robert Carter
- 👤 Pasquale Straccia
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 18:08
CPC Classifications
G; G07; G07C; G07C9/00; G07C9/00174; G07C9/00182; G07C9/20; G07C9/28; G07C2009/00753; G07C2009/00769; G07C2009/00785; G07C2009/00801
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
93 words
A communication link comprising a transmitter arranged to transmit a carrier wave modulated by a two-level signal and a receiver for receiving the modulated carrier wave, characterized in that the transmitter (4) is arranged transmit, in a predetermined portion of each of a plurality of consecutive time windows, a burst of carrier wave representing the first signal level or a gap in the carrier wave representing a second signal level, and the receiver (2) is arranged to provide a interference-indicating signal upon detection of signals outside the predetermined portions of the time windows.
Claim 2
Dependent Claim
93 words
A communication link comprising a transmitter arranged to transmit a carrier wave modulated by a two-level signal and a receiver for receiving the modulated carrier wave, characterized in that the transmitter (4) is arranged transmit, in a predetermined portion of each of a plurality of consecutive time windows, a burst of carrier wave representing the first signal level or a gap in the carrier wave representing a second signal level, and the receiver (2) is arranged to provide a interference-indicating signal upon detection of signals outside the predetermined portions of the time windows.
Claim 3
Dependent Claim
49 words
A locking system including a communication link as claimed in claim 1, in which the transmitter (4) is arranged to transmit a predetermined code and the receiver (2) is arranged to receive codes and to provide an access-permitting signal when a received code is identified as the predetermined code.
Claim 4
Dependent Claim
16 words
A system as claimed in claim 2, in which the carrier wave comprises infra-red electromagnetic radiation.
Claim 5
Dependent Claim
16 words
A system as claimed in claim 2, in which the carrier wave comprises ultrasonic acoustic waves.
Claim 6
Independent Claim
28 words
A system as claimed in any one of claims 2 to 4, in which the predetermined code is in the form of binary code representing a predetermined number.
Claim 7
Independent Claim
42 words
A system as claimed in any one of claims 2 to 5, in which the receiver (2) is arranged to produce an alarm signal upon receipt of a number of codes, greater than a predefined number, not identified as the predetermined code.
Claim 8
Dependent Claim
33 words
A system as claimed in claim 6, in which the receiver (2) includes transmitting means for transmitting a signal indicative of tampering upon receipt of more than the predefined number of unidentified codes.
Claim 9
Dependent Claim
36 words
A system as claimed in claim 7, in which the transmitting means is arranged to send a predefined code, different from the predetermined code, to permit identification of the system which is being subjected to tampering.
Claim 10
Dependent Claim
32 words
A system as claimed in claim 8, in which the transmitter (2) includes receiving means for receiving the signal indicative of tampering, and is arranged to respond only to the predefined code.
References Cited (Backward Citations)
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