Fold-back led lighting optical system

Abstract

The invention relates to the technical field of collimating optical system of LED lighting, in particular to a turn-back type LED lighting optical system. The turn-back type LED lighting optical system comprises a free curved-surface lens and a free curved-surface reflector. The free curved-surface lens and the free curved-surface reflector are coaxial with the spacing ranging from 0.01m to 0.1m; the free curved-surface lens comprises a first curved surface, a second curved surface, a third curved surface, a fifth curved surface and a fourth curved surface, the first curved surface, the second curved surface and the fifth curved surface are rotationally symmetrical free curved surfaces, the third curved surface is a rotational paired paraboloid, and a focal point of the paraboloid is a virtual light point of reflected ray of the second curved surface, and the fourth curved surface is a cylindrical surface and used for connecting the third curved surface and the fifth curved surface. The free curved-surface reflector is composed of three curved surfaces. By the arrangement, optional viewing angles can be lit, and lighting effect of the optical system cannot be lowered due to total reflection.

Description

Technical field [0001] The present invention relates to the technical field of collimating optical systems for LED lighting, in particular to a reentrant LED lighting optical system. technical background [0002] As a new type of light source, LED has become a perfect substitute for traditional light sources such as incandescent lamps and fluorescent lamps due to its high luminous efficiency, long life, and non-toxicity. However, since the light intensity distribution of the LED is a circular Lambertian distribution, if it is directly applied to lighting, it will form an extremely uneven illuminance distribution on the target surface, which cannot meet the requirements of various lighting occasions for the optical performance of the lamp. In order to make the LED better used in the lighting field, it is necessary to design a secondary optical system to redistribute the light intensity distribution of the LED so that it can form a uniform or other specific illuminance distribution...

AI Technical Summary

Problems solved by technology

[0004] Although the LED secondary lens can realize the predetermined illumination of the target surface, there are still the following problems: (1) Due to the phenomenon of total reflection when the light propagates from the optically dense medium to the optically sparse medium, when the illumination field angle is greater than 60 degrees , due to the existence of total reflection phenomenon, the optical efficiency of the lens decreases continuously with the increase of the viewing angle; (2) According to the definition of brightness, the smaller the size of the light source, the higher the brightness, and the more "glare" people feel at this time "

Compared with the LED secondary lens, the field of view of the reflective LED secondary optical system is not limited, and there is no "glare" phenomenon, but in actual use, due to the need to install LED chips, heat sinks, PCB boards and other devices, there are The occlusion problem will cause that the light emitted by the LED cannot be fully utilized or part of the light cannot be directly irradiated to the target surface through the shaping of the optical system

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