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US 5,461,386 AGranted
Inductor/antenna for a recognition system
AssigneeTexas Instruments Incorporated
InventorMichael Knebelkamp
Life of this patent
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AssigneeTexas Instruments Incorporated
InventorMichael Knebelkamp
Estimating the term…
An improved inductor/antenna (100)improves the selectivity of a recognition system (10) by ensuring that only the transponder (14) closest to the inductor/antenna (100) of an interrogator (12) receives therefrom, and reacts to, an interrogation signal (S1). The improved inductor/antenna (100) also receives the resulting recognition signal (S2) from the transponder (14)for analysis by the interrogator (12). The inductor/antenna (100) includes two or more coils (102,104; 124,126,128,130; 132,134) which may be wound on ferromagnetic cores (108), spaced around a metal mass (46,48) such as a lock cylinder (46) of an ignition switch (24). The shape, number, location and relative winding sense of the coils are selected to shape and locate the energy field (F; 118,122) radiated by the inductor/antenna (100) so that only the transponder (14) in a key (26) which is inserted into or operating the ignition switch (24) responds to the interrogation signal (S1) radiated by the inductor/antenna (100).
An improved inductor/antenna for a transmitter/receiver associated with a control mechanism which is operable by a properly positioned, matching member to control a device;
An improved inductor/antenna for a transmitter/receiver associated with a lock which is operable by an inserted matching key to control a device;
Dependencies are inferred from the claim text.