Wide-angle lens used for uniform near-field illumination

Abstract

The invention provides a wide-angle lens used for uniform near-field illumination. The wide-angle lens comprises an inwards concave face, an outwards convex face, a bottom face and a positioning support. The inwards concave face is a light source incident face, is a staged discontinuous curved face and is used for diverging incident light. The outwards convex face is a light emitting face and is determined through distribution of emitted light intensity. The emitted light intensity can be obtained according to the energy conservation formula, and the outwards convex face controls the direction of the emitted light. The bottom face is a reflective face. The lens can effectively increase the light emitting angle of light emitting diodes and improve target surface edge illuminance. By means of the lens, the use number of the light emitting diodes and the distance between the lens and a target surface can be reduced, production cost is reduced to a certain extent, and illuminance uniformity of the target surface can be guaranteed.

Description

technical field [0001] The invention belongs to the field of optical lenses, in particular to a wide-angle lens with uniform illumination in the near field. Background technique [0002] In recent years, light-emitting diodes have the advantages of high efficiency, good light and color performance, and low energy consumption, and have been widely used in indoor and outdoor lighting and backlighting. Among them, panel lights, advertising light boxes and displays in the form of flat light are widely used. [0003] From the structural point of view, the application of planar lighting can be divided into two types: side-type and direct-type lighting. Side-lit lighting requires a light guide plate to reflect the incident light from the LEDs. The side-type lighting is small in size, and the technology of the light guide plate is relatively mature. However, there are low coupling efficiency, high cost, and limited size of the light-emitting surface between the light-emitting diod...

AI Technical Summary

Problems solved by technology

However, there are low coupling efficiency, high cost, and limited size of the light-emitting surface between the light-emitting diode and the light guide plate, so it is more suitable for small-area light output, such as mobile phones, computer display screens, tablet computers, etc.

In traditional direct lighting, LEDs are directly arranged at the bottom of the target surface. Since LEDs are similar to Lambertian illuminants, the illuminance will rapidly decay with the increase of distance, resulting in an unsatisfactory superposition effect of edge illuminance. Therefore, direct lighting requires High-density arrangement of light-emitting diodes can form the effect of uniform light output on the target surface, but it is easy to increase the cost and thickness

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