Light emitting diode light source

A light emitting diode light source including a reflective cover and a plurality of light emitting diodes is provided. The reflective cover has an inner surface and an opening for irradiating light. The light emitting diodes are disposed on the inner surface of the reflective cover. The light emitted from the light emitting diodes is incident upon the inner surface of the reflective cover and then reflected toward the opening from the inner surface.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light source device. More particularly, the present invention relates to a light emitting diode light source.

2. Description of the Related Art

Because light emitting diode (LED) has a long working life and a low power rating, LED has found an increasing number of applications including large electronic bill boards, street lights and car lights, for example. At present, manufacturers are aiming towards producing LED with a higher brightness level and a lower light wear out rate. Moreover, LED is also expected to work as a light source for high luminosity projectors such as the digital light processing (DLP) projectors, the liquid crystal display (LCD) projectors and other innovative colored high-luminosity optical projection devices.

Because the dispersion angle of the light emitted from the light emitting diode often exceeds 120 degree, it is difficult to concentrate the light emitted from the light emitting diode. However, if the light emitted from the light emitting diode is not concentrated, the brightness level of a light source system using light emitting diodes as the light source is subjected to substantial limitation.

At present, one method for increasing the brightness of a light emitting diode light source is to increase the supply electric potential to the light emitting diodes. Yet, the defects of this method is that not only will the power rating of the light source system increase, but the bulk of the light source system will also increase due to the need for additional external circuits. A large and bulky light source is a big disadvantage for the miniaturization of all kinds of display or illumination equipment.

SUMMARY OF THE INVENTION

Accordingly, at least one objective of the present invention is to provide a light emitting diode light source capable of improving the problem of insufficient brightness in a conventional light emitting diode light source due to the inability to concentrate the light.

To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a light emitting diode light source comprising a reflective cover and a plurality of light emitting diodes. The reflective cover has an inner surface and an opening for irradiating light. The light emitting diodes are disposed on the inner surface of the reflective cover. The light emitted from the light emitting diodes is incident upon the inner surface of the reflective cover and then reflected toward the opening from the inner surface.

According to one preferred embodiment of the present invention, the light emitting diodes are selected from a group consisting of light emitting diodes that emit red light, green light, blue light, white light, cyan light, yellow light, magenta light or any combination of the above colors.

According to one preferred embodiment of the present invention, the light emitting diodes are organized to form a ring around the inner surface of the reflective cover.

According to one preferred embodiment of the present invention, the light emitting diode light source further comprises at least an optical element disposed at the light irradiation opening of the reflective cover. In one embodiment, the optical element includes a field lens.

According to one preferred embodiment of the present invention, the light emitting diode light source further comprises a cooling device disposed on an outer side of the reflective cover.

According to one preferred embodiment of the present invention, the inner surface of the reflective cover further includes a reflective coating layer thereon. The reflective coating layer includes a mirror coating material.

According to one preferred embodiment of the present invention, the reflective cover is fabricated using a metallic material.

In the present invention, the combination of the light emitting diodes and the reflective cover concentrates the light energy produced by the light emitting diodes. Consequently, the light emitting diode light source can have a sufficiently high brightness level.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a schematic cross-sectional view of a light emitting diode light source according to one preferred embodiment of the present invention. As shown inFIG. 1, the light emitting diode light source120in the present invention comprises a reflective cover100and a plurality of light emitting diodes110. The reflective cover100has an outer surface102, an inner surface104and a light irradiation opening106. The reflective cover100is fabricated using any material with known reflective property such as a metallic material. Here, the reflective cover100has a curved profile and the front end of the reflective cover100has an opening, that is, a light irradiation opening106. The back end of the reflective cover100has a curved corner surface.

In one preferred embodiment, the inner surface104of the reflective cover100further includes a reflective coating layer108thereon for increasing the reflectivity of the inner surface104of the reflective cover100. The reflective coating layer108is fabricated using a mirror coating material, for example.

The light emitting diodes110are disposed on the inner surface104of the reflective cover100. Furthermore, the light emitted from the light emitting diodes110is incident upon the inner surface104of the reflective cover100and then reflected from the inner surface104of the reflective cover100toward the light irradiation opening106. Here, the light emitting diodes110can be disposed anywhere on the inner surface104of the reflective cover100as long as the light114emitted from the light emitting diode110can reach the inner surface104and reflect from there toward the light irradiation opening106. Thus, the present invention has no particular restrictions regarding the orientation or positioning of the light emitting diodes110. In one embodiment, the light emitting diodes110can be positioned around the inner surface104of the reflective cover100in the form of a ring as shown inFIG. 2.FIG. 2is a front view of the light emitting diode light source inFIG. 1. In another embodiment, the light emitting diodes110can be disposed on the surface104(not shown) of the reflective cover100in an irregular manner.

It should be noted that the light emitting diodes110disposed on the inner surface104of the reflective cover100are selected from a group consisting of light emitting diodes that emits red light, green light, blue light, white light, cyan light, yellow light, magenta light or some combination of the above colors. In other words, the light emitting diodes110on the inner surface104of the reflective cover100can emit one, two, three or more types of colored lights depending on the actual color requirements of the light source. For example, if the light emitting diode light source120needs to emit white light, the light emitting diodes110on the inner surface104of the reflective cover100can be light emitting diodes that emits white light. Alternatively, light emitting diodes that emits red light, green light and blue light can be disposed on the inner surface104of the reflective cover100so that the lights from these light emitting diodes110are blend together to produce white light. Similarly, if the light emitting diode light source120needs to emit light of another color, a suitable combination of red, green, blue, white, cyan, yellow and magenta light emitting diodes can be selected and blended together to produce the desired color.

In the present invention, the combination of a plurality of light emitting diodes110and a reflective cover110is able to concentrate the light emitted from the light emitting diodes110so that the light emitting diode light source120can have sufficiently high brightness level. Thus, the present invention can resolve the problem of a conventional light emitting diode light source not having enough brightness level. Furthermore, the present invention does not require a high electric potential for increasing the brightness level. Hence, aside from reducing power consumption, there is no need to incorporate additional external circuits that might increase the volume of the light source and render the light source bulky.

Aside from the light emitting diodes110and the reflective cover100, the light emitting diode light source120of the present invention may further include an optical element112disposed outside the light irradiation opening106of the reflective cover100. The optical element112can be a field lens for focusing the light114emitted by the light emitting diodes110and reflected by the reflective cover100even more, for example.

In addition, the light emitting diode light source120of the present invention may further include a cooling device116disposed just outside the reflective cover100. The cooling device116can be disposed on the backside of the reflective cover100or tiled on the outer surface102of the reflective cover100. The cooling device116carries away the heat generated by the light emitting diode light source while in operation.

The light emitting diode light source120of the present invention can be applied to a variety of products that demands a light source. For example, the light emitting diode light source can be used in the light source system of a display, illuminating equipment and lighting equipment for producing special lighting effects and so on.

In summary, the light emitting diode light source formed by the special arranging the light emitting diodes inside the reflective cover is able to concentrate the light emitted from the light emitting diodes. Hence, the light emitting diode light source can have a sufficiently high brightness level for illumination. In addition, the light emitting diode light source has no need for a high electric potential to increase the brightness level of the light emitting diodes. Thus, aside from saving electric power, the light emitting diode light source is less bulky.