Patent Application
20100128474
1. Field of the Invention
The invention relates to LED (light emitting diode) lamps, and, more particularly, to an LED lamp having an improved lens, whereby light generated by the LED lamp can have a better pattern of distribution.
2. Description of Related Art
The technology of LEDs has rapidly developed in recent years from indicators to illumination applications. With the features of long-term reliability, environment friendliness and low power consumption, the LED is viewed as a promising alternative for future lighting products.
A conventional LED lamp comprises a heat sink, a plurality of LED modules having LEDs attached to an outer surface of the heat sink to dissipate heat generated by the LEDs and a transparent envelope mounted on the heat sink and covering the LED modules therein. The outer surface of the heat sink generally is planar and the LEDs are arranged close to each other. The envelope is used to protect the LEDs from damage. The LED lamp further has a lens for directing light generated by the LEDs to have a desired pattern of distribution, thereby meeting a set lightening requirement. However, the conventional lens cannot enable the light generated by the LEDs to have an optimal pattern of distribution.
What is needed, therefore, is an LED lamp which can overcome the disadvantages of the prior art.
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
The LED modules 30 are divided into two spaced, parallel rows along a direction from a front end to a rear end of the printed circuit board 10. Two adjacent LED modules 30 of each of the rows are spaced from each other. The two lenses 50 cover the two rows of the LED modules 30, respectively.
Referring to
The bottom surface 512 includes a first central surface 512a directly over the LED modules 30 and two first lateral surfaces 512b respectively adjoining two ends of the first central surface 512a. The top surface 514 includes a second central surface 514a corresponding to the first central surface 512a of the bottom surface 512 and two second lateral surfaces 514b respectively adjoining two ends of the second central surface 514a. Each of the first central surface 512a and the second central surface 514a is an arc-shaped surface. The first central surface 512a and the second central surface 514a have different curvatures. The curvature of the first central surface 512a is larger than that of the second central surface 514a. The curvature of the second central surface 514a is smaller than that of each of the second lateral surfaces 514b. The curvature of the first central surface 512a is smaller than that of each of the first lateral surfaces 512b.
The two first lateral surfaces 512b are corresponding to the two second lateral surfaces 514b, respectively. The curvature of each of the two first lateral surfaces 512b is larger than that of each of the two second lateral surfaces 514b. The two first lateral surfaces 512b can have a same curvature or different curvatures. Similarly, the two second lateral surfaces 514b can have a same curvature or different curvatures. In the present embodiment, the two first lateral surfaces 512b have a same curvature, and the two second lateral surfaces 514b have a same curvature.
Regarding the light emitted from the LED modules 30, one portion of the light moves upwardly to enter the body 51 of the lens 50 via the first central surface 512a, and spreads outside of the body 51 of the lens 50 from the second central surface 514a. That is, on the second central surface 514a of the body 51, a part of the light which corresponds to a central portion of the second central surface 514 is not refracted and directly spreads outside of the body 51; another part of the light which corresponds to opposite portions of the second central surface 514 is refracted by the second central surface 514 before it enters the ambient air. The another part of the upwardly moved light is first refracted by opposite portions of the first central surface 514 before it enters the body 51 of the lens 50. Another portion of the light emitted from the LED modules 30 enters the body 51 from the two first lateral surfaces 512b of the bottom surface 512. Due to the curvatures of the two first lateral surfaces 512b being larger than those of the two second lateral surfaces 514b, the another portion of the light emitted from the LED modules 30 is refracted twice with different degrees (first by the two first lateral surfaces 512b of the bottom surface 512 of the lens 50 and then by the two second lateral surfaces 514b of the top surface 514 of the lens 50) to radiate from the lens 50. Thus, a total internal reflection phenomenon occurring at the top surfaces 514 of the lenses 50 can be greatly avoided. The light emitted from the LED modules 30 is oriented toward a plurality of different directions, whereby the LED lamp 100 in accordance with the present disclosure can have a large illumination angle.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the present disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810305731.1 | Nov 2008 | CN | national |
