A design method of LED free-form surface lens

Abstract

The invention discloses a design method for an LED freeform curved lens. The lens comprises a first reflecting surface (11) and a second refracting surface (12). A designing method of the first reflecting surface (11) and the second refracting surface (12) comprises the steps of designing the inner surface of the lens and designing the outer surface of the lens. The invention further discloses theLED freeform curved lens. The inner surface of the lens is designed as a hemispherical surface, so that light, at the angle of 180 degrees, of an LED light source is collected advantageously, and thelight flux utilization rate is increased. The outer surface of the lens comprises the first reflecting surface and the second refracting surface. The design method of the LED freeform curved lens issimple, and uniform illumination of limited light patterns of far and near fields can be achieved, and high efficiency and uniformity are further achieved.

Description

technical field [0001] The invention relates to the technical field of LED lighting, in particular to a design method of an LED free-form surface lens. Background technique [0002] LED light sources are generally Lambertian distributed, and direct lighting cannot achieve uniform lighting. There are many ways to distribute light to LEDs, and the optical system is composed of designed reflective cups and lenses. Among them, there are spherical lenses and free-form surface lenses. Compared with spherical lenses, free-form surface lenses can better control the divergence angle of the light source, so as to better meet the lighting requirements. At present, there are some design methods for LED free-form surface lenses. For example, according to the energy topology relationship between the light source and the target surface, the first-order linear partial differential equation of the free-form surface is derived, and the free-form surface is obtained by numerical calculation u...

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Problems solved by technology

At present, there are some design methods for LED free-form surface lenses. For example, according to the energy topology relationship between the light source and the target surface, the first-order linear partial differential equation of the free-form surface is derived, and the free-form surface is obtained by numerical calculation using Runge-Kutta and finite difference methods. Reflector, this method has higher uniformity and luminous flux utilization rate, but the calculation of the first-order partial differential equation is complicated and difficult to program; another method is to use the arithmetic sequence to change the size division of the light source grid, so as to offset each The influence of various errors on the model is used to achieve uniform distribution of illumination; this method is relatively simple in programming, and has a better effect on far-field optics, but the near-field effect is not obvious

In addition, there is also the use of finite elements to divide the surface light source, and according to the rectangular uniform illumination light distribution condition, the energy corresponding relationship between the light source and the target surface is established to solve the free-form surface reflector. There is a certain dark area in the center, which affects the lighting effect, and the design method is complicated and requires high manufacturing and processing technology

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