Illuminative device

• US 7,052,161 B2
• Filed: 11/21/2002
• Issued: 05/30/2006
• Est. Priority Date: 12/18/2001
• Status: Expired due to Fees

• Current Assignee: Evonik Rã¶Hm GmbH (Rag-Stiftung)
• Original Assignee: Roehm GmbH & Co. KG
• Inventors: Schmidt, Jann, Ittmann, Guenther, Lichtenstein, Hans, Albrecht, Eduard
• Primary Examiner(s): Luebke, Renee
• Assistant Examiner(s): MACCHIAROLO, LEAH SIMONE
• Application Number:
  US10/492,362
• Publication Number:
  US 20050002189A1
• Time in Patent Office: 1,286 Days
• Field of Search: 362/311, 362/351
• US Class Current: 362/311.04
• CPC Class Codes: F21V 3/04 characterised by materials, surface treatments or coatings
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia

Abstract

The invention relates to an illuminative device essentionaly comprising a light source and a diffusing cover which is assigned to the light source and is made of colored plastic. The light source consites of one or several light-emitting diodes (LEDs) emitting a colored an substantially monocromatic light. The diffusing cover assigned thereto has a transmition (DIN 5036) of at least 35% and a reflection (DIN 5036) of at least 15% with the wavelength of the light-emitting diode operating at relative maximum energy.

Claims

1. An illuminatable device, comprising:

a light source; and

a light-scattering cover associated with the light source made of colored plastic,

wherein the light source includes one or more light-emitting diode (LED) that emit colored, essentially monochromatic light, and the associated light-scattering cover has a transmission, measured according to DIN 5036, of at least 35% and a reflection, measured according to DIN 5036, of at least 15% at a wavelength of maximum relative energy of the light-emitting diode.

2. A device according to claim 1, wherein the one or more LED and the light-scattering cover are associated with one another at a distance of from 3 to 12 cm.

3. A device according to claim 1, wherein the light-scattering cover includes a moulded or extruded polymethyl methacrylate plastic.

4. A device according to claim 1, wherein the plastic of the light-scattering cover has a light-scattering power, measured according to DIN 5036, of at least 0.5.

5. A device according to claim 4, wherein BaSO₄, polystyrene, or light-scattering beads made of a crosslinked plastic are contained in the light-scattering cover.

6. A device according to claim 5, wherein BaSO₄ or polystyrene are contained in an amount of from 1.5 to 2.5 wt. %.

7. A device according to claim 1, wherein the one or more LED is located in a box or frame covered by the light-scattering cover.

8. A device according to claim 1, wherein color loci of transmission and re-emission of the colored cover made of plastic, with respect to a standard color chart, lie in a region which, with respect to a straight line that passes through achromatic point (x/y=0.33/0.33) and color locus of the one or more LED, lies no more than 0.2 x/y units away from color locus of the one or more LED in the direction of the straight line and no more than 0.05 x/y units away at right angles on both sides of the straight line.

9. A device according to claim 1, wherein the one or more LED emits yellow light and has a color locus in a region of coordinates x/y=0.5/0.5 /−

0.02.

10. A device according to claim 9, wherein the plastic of the light-scattering cover is colored with from 0.075 to 0.09 wt. % of pyrazolone yellow and from 0.002 to 0.004 wt. % of perinone orange.

11. A device according to claim 1, wherein the one or more LED emits red light and has a color locus in a region of coordinates x/y=0.67/0.33 /−

0.02.

12. A device according to claim 11, wherein the plastic of the light-scattering cover is colored with from 0.13 to 0.17 wt. % of pyrazolone yellow and from 0.01 to 0.03 wt. % of anthraquinone red.

13. A device according to claim 11, wherein the plastic of the light-scattering cover is colored with from 0.055 to 0.07 wt. % of naphthol AS and from 0.005 to 0.015 wt. % of DPP red.

14. A device according to claim 1, wherein the one or more LED emits green light and has a color locus in a region of coordinates x/y=0.16/0.73 /−

0.02.

15. Device according to claim 14, wherein the plastic of the light-scattering cover is colored with from 0.01 to 0.025 wt. % of Cu phthalocyanine green and from 0.025 to 0.045 wt. % of pyrazolone yellow.

16. Device according to claim 1, wherein the one or more LED emits blue light and has a color locus in a region of coordinates x/y=0.14/0.06 /−

0.02.

17. Device according to claim 16, wherein the plastic of the light-scattering cover is colored with from 0.05 to 0.1 wt. % of ultramarine blue and from 0.005 to 0.01 wt. % of anthraquinone blue.

18. Device according to claim 16, wherein the plastic of the light-scattering cover is colored with from 0.007 to 0.013 wt. % of anthraquinone blue.