A DEVICE FOR MODIFYING LIGHT DISTRIBUTION

• US 20190323682A1
• Filed: 12/19/2017
• Published: 10/24/2019
• Est. Priority Date: 01/19/2017
• Status: Active Grant

• Current Assignee: Ledil Oy (Ledil Group Oy)
• Original Assignee: Ledil Oy (Ledil Group Oy)
• Inventors: SAARNIO, Olli
• Granted Patent: US 10,760,770 B2
• Time in Patent Office: Days
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0066 specially adapted to cooperate with point like light sources; specially adapted to cooperate with light sources the shape of which is unspecified F21V7/16 - F21V7/30 take precedence
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A device for modifying light distribution includes a transparent body including a first surface, a second surface on an opposite side of the transparent body, and a third surface joining the first surface. The second surface defines a cavity opening away from the first surface. The second surface reflects, towards the third surface, at least a part of light received via the first surface. The third surface reflects, towards the second surface, the light reflected from the second surface. The second surface acts as a light egress surface for the light reflected from the third surface. The third surface includes a groove so that a part of the light reflected from the second surface propagates across the groove prior to being reflected from the third surface. The light distribution can be tuned by adjusting the shape, the size, and/or the location of the groove.

Claims

1. A device for modifying light distribution, the device comprising a transparent body made of transparent material having refractive index greater than one, and the transparent body comprising a first surface, a second surface on an opposite side of the transparent body with respect to the first surface, and at least one third surface joining the first surface, wherein:

the second surface defines a cavity opening away from the first surface,

the second surface is configured to reflect, towards the third surface, at least a part of light received via the first surface,

the third surface is configured to reflect, towards the second surface, the light reflected from the second surface, and

the second surface is configured to act as a light egress surface for the light reflected from the third surface,

wherein the third surface comprises at least one groove on a propagation path of a part of the light reflected from the second surface so that the part of the light reflected from the second surface propagates across the groove prior to being reflected from the third surface.

2. The device according to claim 1, wherein the transparent body is substantially rotationally symmetric.

3. The device according to claim 1, wherein the cavity defined by the second surface is substantially conical.

4. The device according to claim 1, wherein the first surface has a substantially planar center zone and a surrounding zone defining a truncated cone whose coning angle opens towards the second surface.

5. The device according to claim 1, wherein a cross-sectional profile of the groove is substantially V-shaped.

6. The device according to claim 1, wherein a cross-sectional profile of the groove has a substantially V-shaped bottom region, a first wall of the groove which is closer to the first surface has an arched cross-sectional profile so that the first wall is convex, and a second wall of the groove which is farther from the first surface has a substantially straight cross-sectional profile.

7. The device according to claim 1, wherein at least a part of the second surface comprises undulations suitable for modifying a distribution of light penetrating the at least part of the second surface.

8. The device according to claim 7, wherein the undulations are grooves and ridges between the grooves, the grooves and the ridges extending from an edge of the second surface towards a bottom of the cavity defined by the second surface.

9. The device according to claim 1, wherein the transparent material is one of the following:

acrylic plastic, polycarbonate, optical silicone, glass.

11. A mold having a form suitable for manufacturing, by mold casting, a piece of transparent material having a shape of a device according to claim 1.

12. The device according to claim 2, wherein the cavity defined by the second surface is substantially conical.

13. The device according to claim 2, wherein the first surface has a substantially planar center zone and a surrounding zone defining a truncated cone whose coning angle opens towards the second surface.

14. The device according to claim 2, wherein a cross-sectional profile of the groove is substantially V-shaped.

15. The device according to claim 2, wherein a cross-sectional profile of the groove has a substantially V-shaped bottom region, a first wall of the groove which is closer to the first surface has an arched cross-sectional profile so that the first wall is convex, and a second wall of the groove which is farther from the first surface has a substantially straight cross-sectional profile.

16. The device according to claim 2, wherein at least a part of the second surface comprises undulations suitable for modifying a distribution of light penetrating the at least part of the second surface.

17. The device according to claim 16, wherein the undulations are grooves and ridges between the grooves, the grooves and the ridges extending from an edge of the second surface towards a bottom of the cavity defined by the second surface.

19. The device according to claim 3, wherein at least a part of the second surface comprises undulations suitable for modifying a distribution of light penetrating the at least part of the second surface.

20. The device according to claim 4, wherein at least a part of the second surface comprises undulations suitable for modifying a distribution of light penetrating the at least part of the second surface.

10. An illuminator system comprising:

at least one light source, and

at least one device for modifying distribution of light emitted by the at least one light source,

the device comprising a transparent body made of transparent material having refractive index greater than one, and the transparent body comprising a first surface, a second surface on an opposite side of the transparent body with respect to the first surface, and at least one third surface joining the first surface, wherein;

the second surface defines a cavity opening away from the first surface,

the second surface is configured to reflect, towards the third surface, at least a part of the light received via the first surface,

the third surface is configured to reflect, towards the second surface, the light reflected from the second surface, and

the second surface is configured to act as a light egress surface for the light reflected from the third surface,

wherein the third surface comprises at least one groove on a propagation path of a part of the light reflected from the second surface so that the part of the light reflected from the second surface propagates across the groove prior to being reflected from the third surface.

18. The illuminator system according to claim 10, wherein the transparent body is substantially rotationally symmetric.