초록 ▼

At a first end of an optic-fiber prism assembly are fiber terminations to contact a relieved surface, e.g. finger (stabilized by a handgrip). In a region where fiber diameter is essentially constant with longitudinal position, light enters the prism, crosses the fibers and enters individual fibers t

At a first end of an optic-fiber prism assembly are fiber terminations to contact a relieved surface, e.g. finger (stabilized by a handgrip). In a region where fiber diameter is essentially constant with longitudinal position, light enters the prism, crosses the fibers and enters individual fibers through their sidewalls, lighting the terminations. To allow crosslighting of the assembly, the fiber-optic numerical aperture (NA) is small: preferably not exceeding one-half. Due to fingerprint etc. detail, fractions of light pass along the fibers; at the assembly second end a detector responds with an electrical-signal array based on the surface relief. The signals are processed to check finger etc. identity and applied to control access to a personal weapon, other equipment, facilities, data, or a money service. FTIR ("frustrated total internal reflection") bright- and dark-field versions have various benefits. For use of small, low-cost detectors--and/or internal-mirror versions that light the finger straight-on--the assembly has a separate element, e.g. a high-NA fiber-optic taper with extramural absorption or "EMA" material (no entry light crosses it). For a weapon, a unitary antibypassing module (which matches a weapon port, and must be present) holds part of the access-control and firing systems. Bullets etc. fire only on a special signal from the module.

대표청구항 ▼

[ What is claimed is:] [1.] Apparatus for acquiring surface-relief data from a relieved surface such as a finger; said apparatus comprising:prism means formed from optical fibers and including:a first end, comprising terminations of the fibers for contact with such relieved surface, anda second end,

[ What is claimed is:] [1.] Apparatus for acquiring surface-relief data from a relieved surface such as a finger; said apparatus comprising:prism means formed from optical fibers and including:a first end, comprising terminations of the fibers for contact with such relieved surface, anda second end, comprising opposite terminations of the same or corresponding fibers, for passage of light traveling along the fibers from the first end;means for projecting light across the fibers in a region where the prism means satisfy at least one physical condition for efficient nonducting transillumination based upon a relationship between indices of refraction in the prism means, for lighting the first-end terminations;wherein a light fraction dependent on contact between such relieved surface and each illuminated first-end termination is ducted from that termination along its fiber; andelectrooptical means for receiving at the second end each light fraction from the first end, and in response forming an electrical signal characteristic of such surface relief.