FIELD OF THE INVENTION

This invention relates to LED (Light Emitting Diode) lamp bulbs. More particularly it discloses improvements to LED lamp bulbs which increase efficiency and performance.

BACKGROUND TO THE INVENTION

White LED'S alter sealing and -packaging in LED lamp bulbs (also called LED lamps) usually have a very wide angle o f light emission. This may be as much as 1 20 to 140 degrees. Various types of focusing lenses have been used with prior art LED lamp bulbs to focus and concentrate this light into a maximum angle of say 15, 25, 38, 45 or 60 degrees or other selected angle according to application requirements. These prior art focusing lenses however are of differing efficiencies and the resultant lumen output of the lamp bulbs after installation may be significantly less than the original LED output.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to ameliorate the

aforementioned disadvantage and accordingly an LED lamp bulb is disclosed which includes one or more LED'S with respective focusing lens, cover or lens holder and reflective surface means adapted to reflect emitted light from said one or more LED'S back inside the focusing lens material.

In one preferred form of the invention said reflective surface means may comprise a reflective surface of said focusing lens. ln another preferred form of the invention said reflective surface means may comprise a reflective surface of said cover or lens holder.

In accordance with another aspect of the invention a plated reflective cover or lens holder surface may be provided for the lamp which is installed together with the focusing lens and forms part of the lens assembly.

Preferably said reflective surface is electroplated with a substance such as Chromium, Silver, Mercury, Aluminium or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

Currently preferred embodiments of the invention will now be described with reference to the attached representations in which - figure 1 is a cross-sectional view of a single LED lamp bulb showing an external surface of the focus ing lens which is electroplated in accordance with a first embodiment of the invention, figure 2 is a perspective view of the focusing lens of

figure 1 fitted into a conventional lens holder, figure 3 is an exploded perspective view of a focusing lens . and cover or lens holder for a single LED lamp bulb, said cover or lens holder being electroplated in accordance with a second embodiment of the invention. e 4 is an exploded perspective view of the focusing lens and cover or lens holder of figure 3 from the opposite end, and es 5 and 6 show exploded and assembled perspective views of a lamp comprising five LED' s. and multiple focusing lenses constructed in

accordance with the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring first to figure 1 there is a focusing lens, indicated generally as 1, for a single LED lamp. In accordance with the invention this focusing lens is preferably formed from Acrylic or

Polymethylmethacrylate (PMMA) material having a high

transparency ratio of preferably 93% or more. The exterior surface 2 of the focusing lens is preferably moul ded using suitable known tools and procedures to produce a highly polished finish. In accordance with the invention this surface is electroplated with a highly reflective material such as Chromium, Silver, Mercury, Aluminium or the like so as to reflect a substantial portion of the emitted light from the LED back inside the focusing lens material. Figure 2 shows this lens 1 fitted into a conventional cover or lens holder 3 for the lamp.

Figure 3 shows an alternative form of the invention in which an interior surface 4 of the cover or lens holder 4A is electroplated with Chromium, Silver, Mercury, Aluminium or the like to reflect light back inside the focusing lens material. A conventional lens 5 may then be fitted into this cover or lens holder 4 as also shown in figures 3 and 4.

While the aforementioned embodiments relate to single LED lamps the invention as shown in figures 5 and 6 can also be applied to light bulbs or lamps with multiple LED'S. In this case there are five focusing lenses 6 for five LED'S (not shown) which fit into respective covers or lens holders 7. The exterior surface 8 of the focusing lenses and/or the interior surfaces of the covers or lens holders themselves are preferably electroplated with said reflective substance in accordance' with the ι n vention.

It will thus be appreciated that this invention at least in the form of the embodiment described provides a novel and useful improvement for increasing the efficiency and performance of LED lamp bulbs. Indeed it has been found by the inventor that the light output of an LED lamp bulb constructed in accordance with this invention can be increased by up to 35% compared with prior art LED lamp bulb assemblies. Clearly however the examples disclosed are only the currently preferred forms of the invention and a wide variety of modifications may be made which would be apparent to a person skilled in the art. For example the shape and configuration of the focusing lens, the design of the cover or lens holder, the substances used for plating the lens holder and/or cover surfaces and the procedures used for forming them may all be changed following further development work by the inventor.