- - The silicone lens
a. Because of the high silica heat resistance ( Can also be reflow soldering) , so often used to encapsulate directly on the LED chip.
b. - general silicone lens are smaller and diameter mm。 PMMA lens
a. Optical PMMA. Poly (methyl methacrylate, commonly known as: acrylic) 。
b. Plastic materials, advantages: high efficiency, Can be done by injection molding, extrusion) ; High light transmittance, Mm thickness transmittance about %) ; Weakness: the temperature cannot exceed & deg; ( The thermal deformation temperature degrees) 。 PC lens
a. Optical material Polycarbonate (. Hereinafter referred to as PC) Polycarbonate.
b. Plastic materials, advantages: high efficiency, Can be done by injection molding, extrusion) ; Light transmittance is a bit low, Mm thickness transmittance about %) ; Weakness: the temperature cannot exceed & deg; ( The thermal deformation temperature degrees) 。 Glass lens
optical glass material, advantage: with high light transmittance, %) , high heat-resistant, etc; Weakness: the shape of a single, fragile, is not easy to achieve mass production, low efficiency and high cost. But at present, our country has very few street lamp manufacturers began to develop glass mould making technology, using the die casting production glass lens, to produce various shapes, special on the surface of the lens.