Side-emitting light guide and method for the production thereof

Patent metadata

Field	Value
Publication number	US-11520096-B2
Application number	US-202017013263-A
Country	US
Kind code	B2
Filing date	Sep 4, 2020
Priority date	Sep 4, 2019
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A light source with a linear appearance is provided. The light source has a flexible light guide that has a homogeneous light emission with high luminance and a emitting light guide. The light emitting guide has a core, in which at least one soul extends, and a transparent cladding that surrounds the core. The core and the cladding are formed from transparent plastic. The core has a higher index of refraction than the cladding. The soul is light-deflecting, light-reflecting, or light-scattering so as to scatter light guided in the light guide and to emit the light through the cladding toward the outside. The soul has a scattering length that is at most twice as large as a maximum cross-sectional dimension of the soul.

First claim

What is claimed is:

1. A side-emitting light guide, comprising
a core;
a soul extending in the core along a longitudinal axis; and
a transparent cladding surrounding the core,
wherein the core and the transparent cladding are formed from transparent plastic with the core having a higher index of refraction than the transparent cladding,
wherein the soul is light-deflecting and scatters light that guided in the light guide to emit the light through the transparent cladding toward an outside,
wherein the soul has a scattering length that is at most twice as large as a maximum cross-sectional dimension of the soul,
wherein the cross section is measured perpendicular to the longitudinal axis, and
wherein the scattering length is defined as a length for which, owing to scattering, an original intensity of the light in an incident direction has declined by a factor of 1/e.

2. The side-emitting light guide of claim 1 , wherein the soul has a cross-sectional area that is smaller by at least a factor of 4 than a cross-sectional area enclosed by an outer contour of the transparent cladding.

3. The side-emitting light guide of claim 1 , wherein the soul has a feature selected from a group consisting of: the soul comprises a cord; the soul comprises a wire; the soul has a diameter of 10 μm to 1000 μm; the soul has a cross-sectional area of 80 μm 2 to 0.8 mm 2 ; the soul varies in a radial direction of the cross section; the soul has a multilayer structure; the soul has an electrical conductor; the soul is an electrical conductor; and any combinations thereof.

4. The side-emitting light guide of claim 1 , wherein the core and the transparent cladding comprise a polymer blend.

5. The side-emitting light guide of claim 1 , wherein the core and the transparent cladding each comprise a polymer blend with at least two compatible polymer components, wherein the at least two compatible polymer components are differently weighted in the core and the transparent cladding so that the index of refraction of the transparent cladding is lower than the index of refraction of the core.

6. The side-emitting light guide of claim 1 , wherein the light guide has a length of 0.5 meter to 100 meters.

7. The side-emitting light guide of claim 1 , further comprising a ratio (Q core /Q soul ) of a cross-sectional area of the soul (Q soul ) to a cross-sectional area of the core (Q core ) that is in a range of 2.5·10 −3 to 0.25.

8. The side-emitting light guide of claim 1 , further comprising a ratio of a diameter of the soul to a diameter of the core in a range of 1/20 to 1/2.

9. The side-emitting light guide of claim 1 , further comprising a ratio ((Q core /Q soul )/L light guide )) of a quotient of a cross-sectional area of the soul (Q soul ) and a cross-sectional area of the core (Q core ) to the length of the light guide (L light guide ) that has a value in a range of 20 m −1 to 500 m −1 .

10. The side-emitting light guide of claim 1 , further comprising:
light losses caused by bending the light guide with a bending radius of 21 mm are less than 0.1 times a total luminous intensity guided in the light guide per winding of the light guide; and/or
light losses caused by bending the light guide with a bending radius of 12 mm are less than 0.3 times a total luminous intensity guided in the light guide per winding of the light guide.

11. The side-emitting light guide of claim 1 , wherein the soul comprises light-scattering elements in a concentration that is greater than 10 particles per cubic millimeter of the soul.

12. The side-emitting light guide of claim 1 , wherein the soul comprises light-scattering elements in a concentration that sufficient so that light impinging on the soul are scattered more than one time on average.

13. The side-emitting light guide of claim 1 , where the light guide comprises a feature to alter a spectrum of emitted light in comparison to a spectrum of coupled-in light, wherein the feature is selected from a group consisting of: pigments or colored scattering particles in the soul; coloring of plastics of the core; coloring of plastics of the transparent cladding; photoluminescent material in the light guide.

14. The side-emitting light guide of claim 1 , wherein the transparent cladding surrounds a plurality of the core.

15. The side-emitting light guide of claim 1 , further comprising a functional element extending in a longitudinal direction of the light guide, the transparent cladding surrounding the functional element.

16. A light source, comprising:
the side-emitting light guide of claim 1 ; and
a light emitter optically coupled to one end of the side-emitting light guide.

17. The side-emitting light guide of claim 2 , wherein the cross-sectional area enclosed by the outer contour of the transparent cladding is at least 0.7 mm 2 .

18. The side-emitting light guide of claim 4 , wherein the polymer blend comprises a component selected from a group consisting of aliphatic polyurethane, thermoplastic elastomer, polymethyl methacrylate, polycarbonate, embedded polymer particles, and any combinations thereof.

19. The side-emitting light guide of claim 4 , wherein the polymer blend of the transparent cladding further comprises an additive selected from a group consisting of a UV stabilizer, a flame retardant, an impact-strength modifier, and any combinations thereof.

20. The side-emitting light guide of claim 4 , wherein the polymer blend comprises polymethyl methacrylate and thermoplastic polyurethane.

21. The side-emitting light guide of claim 4 , wherein the polymer blend comprises particles with cross-linked PMMA.

22. The side-emitting light guide of claim 15 , wherein the functional element is selected from a group consisting of an electrical conductor, a reinforcement element, and combinations thereof.

Assignees

• Schott Ag

Inventors

• Kappel Markus
• Hoppe Bernd
• Russert Hubertus
• Willmes Lothar

Classifications

• G02B1/046

  characterised by the core material · CPC title

• G02B6/0001

  specially adapted for lighting devices or systems (lighting or signalling on vehicles using light guides B60Q1/00; lighting devices for vehicle dashboards B60Q3/10; lighting devices for vehicle interior using light guides B60Q3/62; lighting devices mounted on the vehicle rear part using light guides F21S43/235; measuring arrangements having light conducting pointers G01D13/265; illumination of liquid crystal displays G02F1/1336; illuminated signs G09F13/00) · CPC title

• G02B6/443

  Protective covering · CPC title

• G02B6/001 Primary

  the light being emitted along at least a portion of the lateral surface of the fibre · CPC title

• G02B1/048

  characterised by the cladding material · CPC title