Abstract: An energy-saving illumination system includes a piezoelectric floor, a revolving door, an accumulator, a light source, and an electrical power sensing device. The piezoelectric floor contains piezoelectric material therein. The revolving door comprises a power generating device. The accumulator is electrically connected to the piezoelectric floor and the power generating device. The light source is electrically connected with the accumulator. The electrical power sensing device is configured to detect the quantity of electric charge in the accumulator; the power generating device of the revolving door charges the accumulator according to the detected result obtained from the electrical power sensing device in respect to the accumulator.

Abstract: A surface light source device includes a plurality of light guide plates spliced together side by side and forming a plurality of jointing interfaces. A plurality of LEDs is attached to a side face of each of the light guide plates. The LEDs are arranged in a linear LED array along the side face of each of the light guide plates. At most one linear LED array is arranged at the jointing interface between each two neighboring light guide plates.

Abstract: An exemplary light emitting diode (LED) assembly includes a cover, a substrate, a LED unit, a first electrode terminal, and a second electrode terminal. The substrate includes a first surface and a second surface on an opposite side of the substrate thereto. The substrate and the cover cooperatively define a cavity. The LED unit is received in the cavity. The first and the second electrode terminals extend from the second surface. The first electrode terminal is electrically connected to one of a positive lead and a negative lead of the LED unit and the second electrode terminal is electrically connected to the other. The second electrode terminal includes a first electrode portion and a second electrode portion symmetrically arranged at opposite sides of the first electrode terminal. The first and the second electrode portions are at least partially symmetrical with respect to the first electrode terminal.

Abstract: A lens for a LED light source includes a first light emitting surface and a light incident surface perpendicular to the optical axis of the lens. The first light emitting surface is a convex surface and opposite to the light incident surface. The lens further includes a second light emitting surface opposite to the light incident surface and adjacent to the first light emitting surface. The thickness between the second light emitting surface and the light incident surface near the optical axis exceeds the thickness between the second light emitting surface and the light incident surface away from the optical axis.