Device for identification by proximity
Patent 4893118 Issued on January 9, 1990. Estimated Expiration Date: 
November 25, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 25, 2007. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesElectronic proximity identification system Identification system with vector phase angle detection Proximity identification system with power aided identifier Device for transmitting of binary data between a mobile data carrier and a stationary station Transponder device Patent #: 4724427 InventorsAssigneeApplicationNo. 125660 filed on 11/25/1987US Classes:340/10.34, Power up235/382, Permitting access235/382.5, Changeable authorization340/5.8, Authentication (e.g., identity)340/10.42Identification onlyExaminersPrimary: Yusko, Donald J.Assistant: Palladino, Brian Attorney, Agent or FirmInternational ClassesG06K 005/00H04Q 007/02 Foreign Application Priority Data1986-11-25 FRAbstractA reader identifies coded electronic badges without contact with the latter, by simple inductive coupling of inductances, the electrical supply of the badge being ensured from a voltage at high frequency F generated by the reader. The code of the badge, composed of a sequence of bits following one another at a frequency f very much less than F, is used to modulate a voltage of intermediate frequency fi comprised between f and F and the thus modulated voltage controls an electronic switch adapted to short-circuit a resonant circuit of the badge. | |
