GB2464919A

GB2464919A - Anti-glare light emitting diode device

Info

Publication number: GB2464919A
Application number: GB0819404A
Authority: GB
Inventors: Chia-Mao Li
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-10-22
Filing date: 2008-10-22
Publication date: 2010-05-05
Anticipated expiration: 2028-10-22
Also published as: GB2464919B; GB0819404D0

Abstract

The lighting device contains a light generation member mounted to the smaller end of a hollow cone-shaped metallic reflective element. A transparent refractive element is positioned by a supporting element at a point of focus of the reflective element's slant side wall and is right on the paths of the light beams. The light beams undergo refraction and reflection inside the refractive element and then travel laterally out of the refractive element. The lateral light beams are further reflected by the slant side wall of the reflective element and travel substantially in parallel out of the larger end of the reflective element, thereby avoiding the strong glare when light beams are directly emitted from the light emitting diode.

Description

TITLE: ANTI-GLARE LIGHTING DEVICE USING LIGHT EMTTflNG

DIODE

(a) Technical Field of the Invention

The present invention generally relates to lighting devices, and more particularly to a lighting device using light emitting diode as light source and structured to avoid glare.

(b) Description of the Prior Art

As shown in FIG 1, a conventional lighting device using quartz light bulb has a positioning element 2 diametrically positioned across a cone-shaped shade 1. Beneath the positioning element 2, there is a blocking element 3 right above the light source so as to block most of the light source's vertical light beams. The lateral light beams, on the other hand, are reflective by shade 1 and therefore distributed across the shade 1 for reduced glare. However, the positioning element 2 and the blocking element 3 increase the complexity of the lighting device and its manufacturing process. Also, the reduced glare is not free; it is the result of sacrificing the brightness of the lighting device.

On the other hand, Taiwan Patent No. M306,299 teaches a lighting device using light emitting diode as light source. The lighting device provides a light guiding element in the paths of the light beams emanated from the light emitting diode to redirect them towards lateral sides so that the lighting device is suitable for indicating, warning, or alarming applications.

SUMMARY OF THE INVENTION

A lighting device using light emitting diode as light source is provided herein. The main purpose of the present invention is to provide a lighting device suitable for projection applications but the light beams are distributed and collimated in parallel to avoid glare and harshness to the eye.

The lighting device contains a light generation member mounted to the smaller end of a hollow, cone-shaped, metallic reflective element and the light beams of the light generation member projects towards the larger end of the reflective element. A refractive element is positioned by a supporting element at a point of focus of the reflective element's slant side wall and is right on the paths of the light beams.

The light beams undergo refraction and reflection inside the refractive element and then travel laterally out of the refractive element. The lateral light beams are further reflected by the slant side wall of the reflective element and travel substantially in parallel out of the larger end of the reflective element, thereby avoiding the strong glare when light beams are directly emitted from the light emitting diode.

The foregoing objectives and summary provide only a brief introduction to the present invention. To frilly appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 is a perspective diagram showing a conventional lighting device.

FIG 2 is a perspective diagram showing the various components of a lighting device according to an embodiment of the present invention.

FIG 3 is a perspective diagram showing the lighting device of FIG 2 after it is assembled.

FIG 4 is a sectional diagram showing the lighting device of FIG 2 and its light trajectories.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following descriptions are exemplaiy embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

As shown in FiGS. 2 to 4, a lighting device according to an embodiment of the present invention contains a solid and transparent refractive element 10, a metallic supporting element 20, a hollow, cone-shaped, metallic reflective element 30, and a light generation member 40.

The light generation member 40 contains a light emitting diode 42 positioned at the center of a disc and protruding vertically from a top surface of the disc for an appropriate distance. A number of bolt holes 410 are provided on the disc, surrounding the light emitting diode 42.

The reflective element 30 has a slant side wall 32 surrounding a flat bottom 31 (i.e., the smaller end of the cone-shaped reflective element 30) with a center through hole 310 and a number of bolt holes 33 surrounding the center through hole 310. The light generation member 40 is fixed to the bottom 31 of the reflective element 30 by driving a number of bolts (not shown) through the bolt holes 410 of the light generation member 40 and the corresponding bolt holes 33 of the reflective element 30 and, as such, the light emitting diode 42 is revealed by the center through hole 310 of the reflective element 30. The light beams from the light emitting diode 42 therefore would project towards a top end (i.e., the larger end) of the cone-shaped reflective element 30.

The supporting element 20 has a through hole 210 at a flat bottom to sleeve over, and therefore is fixed to, the light emitting diode 42 inside the reflective element 30. Surrounding the through hole 210, the supporting element 20 has a side wall slanting outward and a flange 21 is provided around a top rim of the side wall. The refractive element 10 is thereby fixedly held at a distance from the light emitting diode 42 by the flange 21. The refractive element 10, thus positioned, is right on the paths of the light beams either directly emitted from the light emitting diode 42 or reflected by the slant side wall of the supporting element 20.

The refractive element 10 has its bottom surface (i.e., the surface facing the light emitting diode 42) concaved inward to form a cone-shaped lower indentation 12 and the slant side wall of the lower indentation 12 converges to a flat surface. The refractive element 10 also has its top surface (i.e., the surface facing away from the light emitting diode 42) concaved inward to form a cone-shaped upper indentation 11 and the slant side wall of the upper indentation 11 converges to a pointed end. As shown in FIG 4, for the light beams emanated from the light emitting diode 42, some directly enter the refractive element 10 and some are reflected first by the slant side wall of the supporting element 20 before entering the refractive element 10, all through the lower indentation 12. These light beams are first refracted by the refractive element 20 and then reflected by the slant side wall of the upper indentation 11 to travel substantially laterally. These lateral light beams are further reflected by the slant side wall 32 of the reflective element 30 to project substantially in parallel out of the larger end of the reflective element 30.

As desêribed, the light beams from the point light source, the light emitting diode 42, are effectively distributed and collimated generally in parallel under the control of the reflective element 30,so as to avoid causing glare or harshness to the eye. Please note that the refractive element 10 is preferably arranged at a point of focus to the slant side wall 32 of the reflective element 30 and, by employing reflective element 30 of an appropriate shape, the light beams of the light emitting diode 42 are effectively controlled and manipulated. Please also note that, in addition to a smooth slant side wall 32 as depicted, the slant side wall 32 could be coafigured to have a plurality of diffusing structures on the light incident surface such as irregularly arranged valleys and peaks (i.e., a roughened surface) so as to scatter the reflected light beams and to achieve uniform brightness.

While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.

Claims

I CLAIM: 1. A lighting device, comprising: a hollow cone-shaped metallic reflective element having a flat smaller end with a through hole; a light generation member having a light emitting diode protruding from a top surface, said light generation member fixedly attached to said smaller end of said reflective element and said light emitting diode thereby exposed by said through hole of said reflective element so that light beams from said light emitting diode project towards a larger end of said reflective element; a metallic supporting element inside said reflective element and fixedly mounted to and exposing said light emitting diode, said supporting element having a side wall surrounding said light emitting diode and slanting outward towards said larger end of said reflective element; and a solid and transparent refractive element fixedly positioned to a top rim of said side wall of said supporting element, a bottom surface of said refractive element facing said light emitting diode concaved inward to form a cone-shaped lower indentation, a top surface facing away from said light emitting diode concaved inward to form a cone-shaped upper indentation; wherein, for said light beams emanated from said light emitting diode, some directly enter said refractive element and some are reflected first by said side wall of said supporting element before entering said refractive element, all through said lower indentation; the light beams are refracted by said refractive element and then reflected by said slant side wall of said upper indentation to travel substantially laterally; and the lateral light beams are further reflected by said slant side wall of said reflective element to project substantially in parallel out of said larger end of said reflective element.
2. The lighting device according to claim 1, wherein said slant side wall of said reflective element has a plurality of difluisirig structures.