Patent ID: 8308321

Claim:
An LED (light emitting diode) unit comprising: an LED having an optical axis; and a lens mounted on the LED, the lens comprising: an incidence surface adjacent to the LED, an emission surface remote from the LED, and a light-reflecting face between the incidence surface and the emission surface, the light-reflecting face having a diameter gradually increasing from a bottom towards a top of the lens, the incidence surface comprising a first incidence surface confronting the LED and a second incidence surface surrounding the LED and extending downwardly from a circumference of the first incidence surface, the second incidence surface protruding inwardly towards the LED, the emission surface comprising a first emission surface at a central portion of a top face of the lens and a second emission surface extending upwardly and outwardly from a circumference of the first emission surface, the second emission surface being a periphery of a conical frustum, wherein light emitted from the LED with a large light-emission angle is refracted by the second incidence surface of the incidence surface into substantially parallel beams in one of two opposite sides of a cross-section of the lens through the optical axis of the LED, and the parallel beams are sequentially reflected by the light-reflecting face and refracted by the emission surface out of the lens in substantially parallel beams.