Patent 7306351 was granted and assigned to Chung Yuan Christian University on December, 2007 by the United States Patent and Trademark Office.
A light emitting device includes an LED package bases, an LED chip disposed on the LED package base, and a lens disposed on the LED package base. The lens includes a frustum shape having an inclined outer peripheral surface, and having a relatively smaller lower portion for attaching onto the LED package base, and having a relatively greater upper portion spaced away from the LED package base, the lens includes a longitudinal axis arranged to have an included angle θ formed between the longitudinal axis and the inclined outer peripheral surface of the lens, for reflecting light sidewise. The lens may include a curved recess formed in the upper portion for such as light diffusing purposes.