Reflective illumination device

• US 20070217193A1
• Filed: 07/21/2006
• Published: 09/20/2007
• Est. Priority Date: 03/17/2006
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute, Toalux Electric Corp.
• Original Assignee: Industrial Technology Research Institute, Toalux Electric Corp.
• Inventors: Sun, Yi-Ting, Hsu, Hsiu-Chen, Lin, Jian-Shian, Lai, Chieh-Lung, Wang, Jian-Chiuan
• Granted Patent: US 7,530,712 B2
• Time in Patent Office: Days
• US Class Current: 362/245
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/09 with a combination of different curvatures
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2103/33 annular
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876

Abstract

A reflective illumination device is disclosed, which is comprised of a light-guiding screen with light reflecting ability and at least a directional light source; wherein the light-guiding screen includes a reflecting surface having a semi-Fresnel lens structure arranged thereon. The semi-Fresnel lens structure, being designed basing on the principle of Fresnel lens, is the equivalent of a parabolic mirror that has spiral cut ridges for focusing light to a focal point, whereas the profile of the ridges can be a planar surface, a curved surface or the combination thereof. By arranging the reflecting surface with semi-Fresnel lens structure at the bottom of the light-guiding screen and each light source at a circumferential side wall of the light-guiding screen, the light beams emitting from each light source can be reflected out of the light-guiding screen by a specific angle as the direction of the light beams is adjusted to pour on the semi-Fresnel lens structure by a specific angle matching the configuration of the same.

Claims

1. A reflective illumination device, comprising:

a light-guiding screen, having a bottom and at least a light-discharging exit formed by the enclosure of a side wall; and

at least a directional light source, each being arranged at the side wall;

wherein, a reflecting surface with at least a semi-Fresnel lens structure is arranged at the bottom of the light-guiding screen for enabling the light beams emitting from each light source to be reflected out of the light-discharging exit by a specific angle as the direction of each light beam is adjusted to pour on the semi-Fresnel lens structure by another specific angle matching the configuration of the same.

2. The reflective illumination device of claim 1, the illumination device having a plurality of light sources, while the angle of light beam emitted form each light source is independently adjusted to match with its corresponding configuration of the semi-Fresnel lens structure, and thus the light beams emitting from different light sources are reflected out of the illumination device by at least one light-discharging angle, in that the light beams are reflected out of the light-guiding screen by at least one discharging angle.

3. The reflective illumination device of claim 1, the illumination device having a plurality of light sources capable of emitting light beams by emitting angles different to each other while enabling the emitted light beams to pour onto a corresponding semi-Fresnel lens structure of the reflecting surface having a plurality of semi-Fresnel lens structures arranged thereon, and thus the light beams emitting from different light source are reflected out of the illumination device by different angles in respective.

4. The reflective illumination device of claim 1, wherein the light-guiding screen is made of a material of light reflecting ability.

5. The reflective illumination device of claim 1, wherein a light reflecting layer is disposed at the inner wall of the light-guiding screen.

6. The reflective illumination device of claim 5, wherein the light reflecting layer is a reflective diffusion film.

7. The reflective illumination device of claim 5, wherein the light reflecting layer is formed by electro-depositing a layer of metal selected from the group consisting of aluminum, electroless nickel, and the like.

8. The reflective illumination device of claim 1, wherein, as the semi-Fresnel lens structure is a structure having a plurality of ridges, the profile of each ridge is a planar surface.

9. The reflective illumination device of claim 1, wherein as the semi-Fresnel lens structure is a structure having a plurality of ridges, the profile of each ridge is a curved surface.

10. The reflective illumination device of claim 1, wherein as the semi-Fresnel lens structure is a structure having a plurality of ridges, the profile of each ridge is a combination of a planar surface and a curved surface.

11. The reflective illumination device of claim 1, wherein the ridges of the semi-Fresnel lens structure are spirally arranged surrounding a pseudo-center.

12. The reflective illumination device of claim 1, wherein the ridges of the semi-Fresnel lens structure are symmetrically arranged with respect to a pseudo-axis.

13. The reflective illumination device of claim 1, wherein the ridges of the semi-Fresnel lens structure are extending while parallel to each other.

14. The reflective illumination device of claim 1, wherein the profile of the reflecting surface is a formation of two inclined planar surfaces being symmetrically arranged with respect to a pseudo-axis while the semi-Fresnel lens structure is formed on the two inclined planar surfaces.

15. The reflective illumination device of claim 1, wherein the profile of the reflecting surface is a formation of two inclined curve surfaces being symmetrically arranged with respect to a pseudo-axis while the semi-Fresnel lens structure is formed on the two inclined curve surfaces.

16. The reflective illumination device of claim 1, wherein the profile of the reflecting surface is a formation of an inclined planar surface and a inclined curve surface, being symmetrically arranged with respect to a pseudo-axis, while the semi-Fresnel lens structure is formed on the two inclined surfaces.

17. The reflective illumination device of claim 1, wherein each directional light source is a light emitting diode (LED).

18. The reflective illumination device of claim 1, wherein the side wall is arranged to surround the circumference of the bottom while enabling the light-guiding screen to have a polygonal contour.

19. The reflective illumination device of claim 1, wherein the side wall is arranged to surround the circumference of the bottom while enabling the light-guiding screen to have a circular contour.

20. The reflective illumination device of claim 1, wherein the light-guiding screen is configured with a plurality side walls while enabling the enclosure of each side wall to form a corresponding light-discharging exit, and thus forming a plurality of light-discharging exits in the reflective illumination device accordingly.