US 5,398,171 AGranted

Light guide termination arrangement for producing a convergent beam output

AssigneeGeneral Electric Company

InventorsJohn M. Davenport, Richard L. Hansler

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Abstract

An illumination system is disclosed which serves to reduce the divergence of a light beam exiting a small diameter optical fiber from what it was upon entering the optical fiber and is particularly suited for automotive forward lighting applications. The illumination system comprises a spherical reflector, a light source, an optical fiber, a hemispherical lens, and an air gap between the planar surface of the hemispherical lens and the output face of the optical fiber. The spherical reflector allows a light beam from the light source to be introduced into the input face of the optical fiber over a wide angle in order to minimize the diameter of the optical fiber. An air gap exists between the planar surface of the hemispherical lens and the output face of the optical fiber that together with the lens are effective in reducing the angular divergence of the beam from what it was upon entering the input face of the optical fiber. The smaller diameter fiber has the advantages of a lighter weight, less cost, greater design flexibility, and ease of manipulation compared to a thicker fiber.

Claims9

Dependent claims

An illumination system for channeling light from one location to a remote location wherefrom a narrow controlled beam of light is delivered, comprising:

a light source,
means for collecting light from said light source,
at least one light guide disposed in proximate relation to said collecting means, said at least one light guide having an output face and input face to which light from said collecting means is introduced to said input face at an angle greater than approximately 60 degrees full angle,
hemispherically shaped lens member having a planar surface disposed in proximate yet in optically non-contacting relation to the output end of said light guide,
air gap disposed between said output face of said at least one light guide and said planar surface of said hemispherically shaped lens, said air gap being effective such that a light output initially diverges upon exiting said output face and prior to impinging upon said planar surface of said hemispherically shaped lens;
and said hemispherically shaped lens having a hemispherical surface, said hemispherically surface of said lens further having a longitudinal axis disposed coincident with said longitudinal axis of said at least one light guide so that light passing from said output face of said light guide is first diverged through said air gap, converged a first time through said planar surface and converged a second time at said hemispherically shaped surface of said lens for output to said remote location and,
wherein said light source has a predetermined arc gap distance and said at least one light guide has a diameter approximately equal to said arc gap distance.

4 more elements

Dependencies are inferred from the claim text.