Simulated neon illumination device using end-lit waveguide

• US 20030198061A1
• Filed: 04/17/2003
• Published: 10/23/2003
• Est. Priority Date: 04/27/2001
• Status: Active Grant

• Current Assignee: iLight Technologies Incorporated (Luminii, LLC)
• Original Assignee: iLight Technologies Incorporated (Luminii, LLC)
• Inventors: Hulse, George R., Cleaver, Mark J., Chambers, Joe A., Dominick, John R.
• Granted Patent: US 6,896,398 B2
• Time in Patent Office: Days
• US Class Current: 362/555
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21V 23/0407 for flashing
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre
• CPC Class Codes: G02B 6/0033 Means for improving the coupling-out of light from the light guide
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity

Abstract

An illumination device for the simulation of neon lighting comprises a leaky waveguide rod having a light-emitting lateral surface and a first set of one or more point light sources positioned adjacent one or both ends of the waveguide rod, the attenuation of light along the length of the waveguide rod being controlled such that light emitted from the lateral surface of the waveguide rod has essentially the same intensity over the length of the waveguide rod.

Claims

1. An illumination device for the simulation of neon lighting, comprising a leaky waveguide rod having a light-emitting lateral surface and a first set of one or more point light sources positioned adjacent one end of said waveguide rod, said waveguide rod leaking light out of said light-emitting lateral surface at an increasing rate along a first predetermined length of said waveguide rod away from said light sources sufficient to essentially balance a rate of attenuation of light in said waveguide rod along said first predetermined length, thereby causing said light emitted from said lateral surface to have essentially the same intensity over at least a portion of said lateral surface.

2. The illumination device of claim 1, in which said leaky waveguide rod is comprised of a material that progressively scatters light away from said point light sources.

3. The illumination device of claim 2, in which the material comprising the waveguide rod is DR acrylic.

4. The illumination device of claim 1, in which said waveguide rod is comprised of an optical waveguide material incorporating micro balloons of glass having an index of refraction different from the index of refraction of said waveguide material, said micro balloons forming a density gradient that increases from said one end along a first predetermined length.

5. The illumination device of claim 4, in which said waveguide material is urethane.

6. The illumination device of claim 4, in which a second set of one or more point light sources is positioned adjacent an opposite end of said waveguide rod and said micro balloons form a second density gradient that increases from said opposite end along a second predetermined length, said first and second predetermined lengths intersecting one another near a midpoint along the length of said waveguide rod.

7. The illumination device of claim 6, in which said first and second pluralities of point light sources are light-emitting diodes.

8. The illumination device of claim 7, in which said light-emitting diodes have an illuminosity of up to approximately 120 lumens.

9. The illumination device of claim 1, in which said waveguide rod has notches on said lateral surface along said first predetermined length that causes increased scattering away from said first end.

10. The illumination device of claim 1, in which said waveguide rod has an internally reflecting member covering an end surface on an opposite end to said first end, said waveguide rod being treated so that light scattering progressively increases from said first end along said first predetermined length to a predetermined point between said one end and said second end and light scattering progressively increases from said opposite end to said predetermined point whereby the intensity of light emitted by said lateral surface is substantial uniform over the entire length of said waveguide rod between said first and second ends.

11. The illumination device of claim 1 in which the waveguide rod has a tubular shape with an internal channel that has a progressively increasing diameter over said predetermined length, said first set of point light sources positioned adjacent an end surface of said waveguide rod at said one end so that light is directed into said end surface and an inner surface defining said channel being partially reflective, whereby light traversing said waveguide rod is increasingly directed out of said lateral surface to balance a rate of attenuation of light in said waveguide rod, thereby providing uniform intensity of light over at least said portion of said lateral surface.

12. An illumination device for the simulation of neon lighting, comprising:

a length of urethane material having first and second ends and a light-emitting lateral surface;

a matrix of micro balloons of glass within said length of urethane having an index of refraction different therefrom, said matrix having a density gradient that increases from a minimum near said first and second ends to a maximum near a midpoint of said length; and

first and second sets of light-emitting diodes associated respectively with said first and second ends of the length of urethane material for emitting light into said ends, whereby light emitted from said light-emitting surface is substantially uniformly emitted between said first and second ends.

13. The illumination device of claim 12, in which said first and second sets of light-emitting diodes are housed respectively within a first and second housing, said first and second housings having interior reflecting surfaces for directing light from said LEDs into said waveguide.

14. The illumination device of claim 13 in which said first and second diodes are embedded in the respective first and second ends of said waveguide rod, and end surfaces of said ends are covered with an internally reflecting material.

15. An optical waveguide system providing for an illumination device simulating the effect of neon and fluorescent lighting, comprising:

an optical waveguide rod of a predetermined length having a characteristic of leaking light directed into an end of said rod out of a lateral surface thereof;

at least one high-intensity point light source adjacent each end of said rod, said point light sources each having an illuminosity of up to approximately 120 lumens; and

said waveguide rod including means for balancing the normal attenuation of emitted light from said ends to near a midpoint of said waveguide rod thereby providing for an emission of light with a substantially uniform intensity along at least a portion of said lateral surface; and

a reflective means positioned about each of said point light sources and associated end of said rod for directing essentially all of the light emitted by each point light source into said ends of said waveguide rod.

16. The optical waveguide system of claim 15, in which said means includes optical waveguide material having a scattering material incorporated therein in which said scattering material increases scattering of light away from said point light sources, thereby balancing normal attenuation of light.

17. The optical waveguide system of claim 16, in which said scattering material comprises micro balloons of glass having a different index of refraction than said waveguide material, said micro balloons forming a density gradient within said waveguide material that increases away from said point light sources and reaches a maximum at a point between said light sources whereby light is increasingly scattered along said waveguide rod toward said point.

18. The optical waveguide system of claim 15, in which said means includes spaced notches on said lateral surface, said notches increasing in number in a direction away from said point light sources and reaching a maximum toward a region between said light sources, whereby said notches increase scattering of light through said lateral surface away from said point light sources.

19. The optical waveguide system of claim 15, in which waveguide rod has a channel extending between said ends with an increasing diameter reaching a maximum at a point between said ends, said channel having an internal surface with a semi-reflective coating, said point light sources being positioned so as to cause light to be directed into end surfaces of said waveguide rod, whereby light is progressively directed out of the lateral surface toward said point to balance the attenuation of light by said system.