Motor vehicle light assembly utilizing total internal reflection

• US 3,969,621 A
• Filed: 11/18/1974
• Issued: 07/13/1976
• Est. Priority Date: 11/18/1974
• Status: Expired due to Term

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Motor Company
• Inventors: Ferrell, Richard M.
• Primary Examiner(s): Moses, R. L.
• Application Number:
  US05/525,034
• Time in Patent Office: 603 Days
• Field of Search: 240/8.2, 240/8.22, 240/8.3, 240/41.1, 240/41.2, 240/41.35 C, 240/7.1 F, 340/87, 340/89, 340/91, 340/93
• US Class Current: 362/299
• CPC Class Codes: B60Q 1/32 for indicating vehicle sides , e.g. clearance lights
• CPC Class Codes: F21S 43/26 Refractors, transparent cover plates, light guides or filters not provided in groups F21S43/235 - F21S43/255
• CPC Class Codes: F21S 43/31 Optical layout thereof
• CPC Class Codes: F21S 43/315 using total internal reflection
• CPC Class Codes: F21S 43/40 characterised by the combination of reflectors and refractors
• CPC Class Codes: F21V 7/0091 using total internal reflection

Abstract

A light assembly for a motor vehicle includes a light source and a parabolic reflector for reflecting light emanating from the light source in the longitudinal direction of the vehicle. A lens is included in the light assembly. The lens is made from a transparent material and is positioned to produce total internal reflection of a portion of the light emanating from the light source and parabolic reflector. The totally internally reflected light rays are projected in a direction transverse to the motor vehicle. This enables a single light assembly to satisfy safety requirements pertaining to light projection both in the longitudinal direction of a vehicle and in its transverse direction.

Claims

1. A light assembly for a motor vehicle, said light assembly being designed to project light both in the longitudinal direction of said motor vehicle and in a direction transverse to said motor vehicle, said light assembly comprising:

a light source;

a parabolic reflector, said light source being positioned at the focal point of said parabolic reflector and said parabolic reflector defining a general direction of light projection;

a lens made from a transparent material, said lens having a plane surface and a surface having a plurality of optics, said lens surface having a plurality of optics including certain portions interspersed among said optics, said surface portions being flat and parallel to said plane surface of said lens, thereby, to permit light rays entering said lens at said surface portions to be transmitted through said lens, said optics being of a type capable of producing total internal reflection of light rays entering said lens from the direction of said parabolic reflector and said light source, and said optics projecting said totally internally reflected light rays in a direction substantially transverse to said general direction.

2. A light assembly according to claim 1 wherein said plane surface of said lens forms an acute angle of from about 40°

to 60°

with respect to said general direction of light projection.

3. A light assembly for a motor vehicle, said light assembly being designed to project light both in the longitudinal direction of said motor vehicle and in a direction transverse to said motor vehicle, said light assembly comprising:

a light source;

a parabolic reflector adapted to be secured to said motor vehicle, said light source being positioned at the focal point of said parabolic reflector and said parabolic reflector being positioned to reflect light emanating from said light source in the longitudinal direction of said motor vehicle;

a transparent housing enclosing said parabolic reflector and said light source;

a lens made from a transparent material, said lens having a plane surface and a surface containing optics for producing total internal reflection in said lens of light incident thereon from said light source and said parabolic reflector, light totally internally reflected by said lens being projected through said transparent housing in a direction substantially transverse to said motor vehicle; and

a second lens interposed between said light source and said first-mentioned lens, said second lens being positioned to transmit light rays emanating from said light source and said parabolic reflector, and said second lens including optic means for collimating light rays and for directing such collimating light rays toward said first-mentioned lens.

4. A light assembly according to claim 3, wherein said plane surface of said first-mentioned lens is positioned at an angle of from about 40°

to about 60°

with respect to the longitudinal direction of said motor vehicle.

5. A light assembly according to claim 4 wherein said transparent housing lens includes optic means for dispersing said light totally internally reflected by said first-mentioned lens, said dispersed light being projected through said housing in a direction substantially transverse to said motor vehicle.

6. A light assembly for a motor vehicle, said light assembly being designed to project light both in the longitudinal direction of said motor vehicle and in a direction transverse to said motor vehicle, said light assembly comprising:

a light source;

a parabolic reflector, said light source being positioned at the focal point of said parabolic reflector and said parabolic reflector defining a general direction of light projection;

a lens made from a transparent material, said lens having a plane surface, forming an acute angle of from about 40°

to about 60°

with respect to said general direction of light projection, and a surface having a plurality of optics, said optics being of a type capable of producing total internal reflection of light rays entering said lens from the direction of said parabolic reflector and said light source, and said optics projecting said totally internally reflected light rays in a direction substantially transverse to said general direction, said lens including optic means for dispersing said totally internally reflected light rays projected in a direction substantially transverse to said general direction.