Total internal reflection(TIR) Fresnel lens is a new type of optical lens which combines total internal reflection and Fresnel refraction technology. It has the concentric ring sturctures that can save most of optical materials as a Fresnel lens does. When in use, the ring structure is oriented to light source, the light is incident from inner interface(towards to center of lens) of each ring, reflected back from the outer interface, and finally emitted from the plane of lens. This folding light path can greatly shorten the distance from light source to lens, so the lens has higher utilization of light. Compared with traditional total reflection lens, the TIR Fresnel lens is lighter, thinner, and has enough space for heat dissipation, so it can be used with higher power LED.
The distance between LED and lens is fixed, beam angle of lens is fixed. One of the ways to change beam angle is to replace chips having different luminous surfaces, the other way is to select LED having the variable luminous surface. When the luminous surface is large, beam angle is wide, but when luminous surface is small, then beam angle is narrow.
The TIR Fresnel Lens product range is providing three sub-ranges, they're Peggy, Kullen and Kullen Glass. The Kullen-Glass is made of glass, compare with the Peggy and Kullen TIR Fresnel lenses, it has higher efficiency and strength so as to be applied to more severe environment.