Optical system with reflectors and light pipes

• US 20100220492A1
• Filed: 06/11/2009
• Published: 09/02/2010
• Est. Priority Date: 06/11/2009
• Status: Active Grant

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Rambus Delaware LLC (Rambus Inc.)
• Inventors: Richardson, Brian Edward
• Granted Patent: US 8,297,818 B2
• Time in Patent Office: Days
• US Class Current: 362/551
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0075 Arrangements of multiple light guides G02B6/0028 takes precedence

Abstract

An optical system utilizing a light pipe in which light travels by total internal reflection (TIR) accurately controls the light exiting the pipe. The system achieves accurate control of the reflected light by selectively extracting light from a limited area of the light pipe. The configuration of the reflectors used for the selective extraction of the light determines the nature of the output light. The reflectors are preferably located on an output side of the light pipe. All light output by the system is directed by the reflectors.

Claims

1. An optical system comprising:

at least one light source,

at least one light pipe wherein light travels by total internal reflection, and

at least one reflector that provides selective extraction of light from said light pipe;

wherein

said reflector is positioned on an output side of said light pipe,

when light is extracted from said light pipe, the light is directed in a direction and pattern determined by a configuration of said reflector, and

all light output by said system is directed from said reflector.

2. The optical system of claim 1 wherein:

said light pipe has a reduction in thickness from a first end at which said light source is located, said reduction in thickness being accomplished by at least one notch that receives said reflector.

3. The optical system of claim 1 wherein:

said light pipe has a tapered reduction in thickness from a first end.

4. The optical system of claim 1 wherein:

said reflector is a two dimensional reflector that controls the direction of output light in one dimension.

5. The optical system of claim 1 wherein:

said reflector is a three dimensional reflector that controls the direction of output light in two dimensions.

6. The optical system of claim 1 wherein:

multiple reflectors are employed for each light pipe.

7. The optical system of claim 1 wherein:

multiple light sources are employed for each light pipe.

8. An optical system comprising:

at least one light source,

at least one light pipe wherein light travels by total internal reflection, and

at least one reflector that provides selective extraction of light from said light pipe;

wherein

said reflector is positioned on an output side of said light pipe,

when light is extracted from said light pipe, the light is directed in a direction and pattern determined by a configuration of said reflector,

all light output by said system is directed from said reflector, and

said light pipe has a reduction in thickness from a first end at which said light source is located.

9. The optical system of claim 8 wherein:

said reduction in thickness is accomplished by at least one notch that receives said reflector.

10. The optical system of claim 8 wherein:

said light pipe has a tapered reduction in thickness from a first end.

11. The optical system of claim 8 wherein:

said reflector is a two dimensional reflector that controls the direction of output light in one dimension.

12. The optical system of claim 8 wherein:

said reflector is a three dimensional reflector that controls the direction of output light in two dimensions.

13. The optical system of claim 8 wherein:

multiple reflectors are employed for each light pipe.

14. The optical system of claim 8 wherein:

multiple light sources are employed for each light pipe.