Optical system for a Light Emitting Diode with collection, conduction, phosphor directing, and output means

• US 20100315802A1
• Filed: 06/11/2009
• Published: 12/16/2010
• 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 8,152,318 B2
• Time in Patent Office: Days
• US Class Current: 362/84
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 13/08 the elements being filters or photoluminescent elements and reflectors
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21V 9/06 for filtering out ultraviolet radiation
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

An optical system with an LED light source utilizes a base with an inverted conical shape to conduct light to a phosphor layer. The phosphor layer emits light from both upper and lower surfaces. The base and a substantially mirror image cap element facilitate efficient extraction of the phosphor-generated light from the optical system so that the output of the system is omni-directional light suitable for common lighting applications. The system is very efficient in that nearly all the light generated by the LED is transmitted to the phosphor layer, and nearly all the light emitted from the phosphor layer is output from the system.

Claims

1. An optical system with an omni-directional output comprising:

an LED that serves as a light source,

a base with a shape of an inverted cone,

a phosphor layer, and

a cone shaped cap;

wherein

light generated by said LED is transmitted both directly and via TIR in said base to said phosphor layer, thereby irradiating said phosphor layer so that light is emitted from said phosphor layer, and

said light emitted from said phosphor layer is extracted from said optical system through said base and said cap both directly and via TIR.

2. The optical system of claim 1 wherein:

light is emitted from both a top side and a bottom side of said phosphor layer when light from said LED contacts said phosphor layer.

3. The optical system of claim 1 wherein:

said phosphor layer is situated near a central region of a main body comprising said base and said cap so that an area of said phosphor layer is much larger than an area of said LED.

4. The optical system of claim 1 wherein:

an area of said base near said LED comprises a reflective medium.

5. The optical system of claim 4 wherein:

in conformations of said system in which an angle of said base does not support a sufficient amount of TIR, at least a portion of said reflective medium is covered with a reflective coating.

6. The optical system of claim 4 wherein:

said reflective medium comprises oil with a high index of refraction.

7. An optical system with an omni-directional output comprising:

an LED that serves as a light source,

a base with a shape of an inverted cone,

a phosphor layer, and

a cone shaped cap;

wherein

light generated by said LED is transmitted both directly and via TIR in said base to said phosphor layer, thereby irradiating said phosphor layer so that light is emitted from both a top side and a bottom side of said phosphor layer, and

said light emitted from said phosphor layer is extracted from said optical system through said base and said cap both directly and via TIR.

8. The optical system of claim 7 wherein:

said phosphor layer is situated near a central region of a main body comprising said base and said cap so that an area of said phosphor layer is much larger than an area of said LED.

9. The optical system of claim 7 wherein:

an area of said base near said LED comprises a reflective medium.

10. The optical system of claim 9 wherein:

in conformations of said system in which an angle of said base does not support a sufficient amount of TIR, at least a portion of said reflective medium is covered with a reflective coating.

11. The optical system of claim 9 wherein:

said reflective medium comprises oil with a high index of refraction.

12. An optical system with an omni-directional output comprising:

an LED that serves as a light source,

a base with a shape of an inverted cone, an area of said base near said LED comprising a reflective medium,

a phosphor layer, and

a cone shaped cap;

wherein

light generated by said LED is transmitted both directly and via TIR in said base to said phosphor layer, thereby irradiating said phosphor layer so that light is emitted from both a top side and a bottom side of said phosphor layer, and

said light emitted from said phosphor layer is extracted from said optical system through said base and said cap both directly and via TIR.

13. The optical system of claim 12 wherein:

said phosphor layer is situated near a central region of a main body comprising said base and said cap so that an area of said phosphor layer is much larger than an area of said LED.

14. The optical system of claim 12 wherein:

in conformations of said system in which an angle of said base does not support a sufficient amount of TIR, at least a portion of said reflective medium is covered with a reflective coating.

15. The optical system of claim 14 wherein:

said reflective medium comprises oil with a high index of refraction.