Free-form surface lens construction method based on lighting of LED desk lamp

Abstract

The invention provides a free-form surface lens construction method based on lighting of an LED desk lamp. According to the method, the mode that the free-form surface lens of the LED desk lamp is obtained in a three-dimensional space is simplified into the mode that the generatrix 1 of the free-form surface of the lens is obtained in a two-dimensional space, coordinates are established with the light source of the LED desk lamp as the origin, the relation between an incident light vector, an emergent light vector and a normal vector is listed according to the Snell law, and an equation is established; an equation can be listed because the radiation flux of the light source of the LED desk lamp is equal to the luminous flux received by a target lighting face, light spots formed on the target lighting face in calculation are even round light spots, and therefore the illuminance E is the same, and the relation between the known coordinates on the target lighting face and the lens free-form surface coordinates can be established. According to the coordinates on the known target face, the generatrix 1 of the free-form surface of the lens is obtained through iteration solution with a numerical method, the generatrix 1 is subjected to data fitting and rotates around an axis so that the free-form surface can be obtained, and the free-form surface is subjected to closed materialization so that the lens can be obtained. Through the method, the effective utilization rate of light and the uniformity ratio of the illuminance are increased.

Description

technical field [0001] The invention relates to a free-form surface lens for LED desk lamp lighting. The light source used in the LED desk lamp is a high-power LED. The free-form surface lens can improve the effective utilization rate and illuminance uniformity of the light emitted by the light source, and belongs to the technical field of LED lighting applications. Background technique [0002] LED desk lamp is exactly the desk lamp that uses LED (Light Emitting Diode) as light source. LED desk lamp is suitable for reading, writing, reviewing and other office or study lighting places, to ensure a good visual environment in the work area, so as to improve the efficiency of office and study. If the illuminance and uniformity of the lighting area are poor, people's vision will be easily fatigued, which will affect work efficiency and vision, so special attention should be paid to the quality of lighting. Compared with traditional light sources, LED lighting has significant ad...

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Problems solved by technology

However, if the LED does not have a reasonable light distribution, the light spot irradiated on the target surface will be too bright in the middle, and the surrounding will become dark and uneven lighting.

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