Printed circuit reader/exciter coil for vehicle security system
US5532522A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1994 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Jun 6, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2009/00777
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A transponder embedded in a key and a reader/exciter coil surrounding the lock cylinder are inductively linked to provide energization to the transponder, causing it to emit a digital identification code. A control circuit associated with the coil supplies energizing coil current and analyzes the emitted code to verify the authenticity of the key. The coil and control circuit are contained in a planar multi-layer hardboard printed circuit having high circuit integrity and being very thin for accommodation in the lock assembly. Alternatively, the coil and control circuit are contained in a flexible printed circuit. There the coil includes two opposed elongated legs which are positioned on opposite sides of the lock cylinder and folded in a way to conform to the cylinder surface, forming in effect a very thin cylindrical coil. An extension on the printed circuit form a path to the control circuit which is remote from the cylinder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.