Reflective illumination device

• US 7,530,712 B2
• Filed: 07/21/2006
• Issued: 05/12/2009
• Est. Priority Date: 03/17/2006
• Status: Expired due to Fees

• Current Assignee: Industrial Technology Research Institute, Toalux Electric Corp.
• Original Assignee: Industrial Technology Research Institute, Toalux Electric Corp.
• Inventors: Lin, Jian-Shian, Lai, Chieh-Lung, Wang, Jian-Chiuan, Sun, Yi-Ting, Hsu, Hsiu-Chen
• Primary Examiner(s): Lee; Y My Quach
• Application Number:
  US11/490,175
• Publication Number:
  US 20070217193A1
• Time in Patent Office: 1,026 Days
• Field of Search: 362/237, 362/240, 362/241, 362/243, 362/247, 362/297, 362/298, 362/301, 362/302, 362/304, 362/327, 362/330, 362/337, 362/340, 362/346
• US Class Current: 362/247
• 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 an enclosure of a side wall, the bottom having at least one plain surface located in an interior of the light-guiding screen; and

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

wherein, a reflecting surface having at least a semi-Fresnel lens structure is arranged on the at least one plain surface located on the bottom of the light-guiding screen, the semi-Fresnel lens reflecting light beams emitting from each light source out of the light-discharging exit at specific angles corresponding to the direction of each light beam directed onto the semi-Fresnel lens structure, the at least one plain surface includes two plain surfaces, the profile of the reflecting surface is a formation of the two plain surfaces being symmetrically arranged with respect to an axis while the semi-Fresnel lens structures are respectively formed on the two plain surfaces.

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

3. The reflective illumination device of claim 1, the at least one directional light source 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 sources 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 on an 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, 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 the ridges of the semi-Fresnel lens structures are symmetrically arranged with respect to an axis thereof.

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

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

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

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

14. The reflective illumination device of claim 1, wherein the light-guiding screen is configured with a plurality of side walls enabling the an enclosure of each side wall of the plurality of side walls to form a corresponding light-discharging exit, and thus forming a plurality of light-discharging exits in the reflective illumination device, the at least one directional light source includes a plurality of light sources, each of the plurality of light sources is located on an upper portion of each of the plurality of side walls.