Light collimation device and application of light collimation device in LED train headlamp

Abstract

The invention discloses a light collimation device which is composed of one or more Fresnel lenses located on the same plane or spherical surface. The upper surfaces of the Fresnel lenses are the Fresnel surfaces, and the light collimation device is characterized in that the designs of center small-angle area transmission and large-angle area total reflection are adopted in the Fresnel lenses. The light collimation device is applied to an LED train headlamp, the LED train headlamp is composed of an LED chip array, a Fresnel lens array and a light reflection cup, the LED chip array is composed of one or more LED chips located on the same plane or spherical surface, the Fresnel lens array is composed of the one or more Fresnel lenses located on the same plane or spherical surface, the Fresnel lenses correspond to the LED chips in position in a one-to-one mode, the upper surfaces of the Fresnel lenses are the Fresnel surfaces, the LED chip array is close to the lower surface of the Fresnel lens array, the Fresnel lens array is surrounded by the light reflection cup, and light which is still large in divergence angle after passing through the Fresnel lens array is further collimated; the LED train headlamp is characterized by further comprising long-distance fluorescent sheets, the LED chip array, the Fresnel lens array and the long-distance fluorescent sheets are sequentially arranged in parallel, and the long-distance fluorescent sheets are also surrounded by the light reflection cup.

Description

technical field [0001] The invention relates to a device for changing the direction of an LED light source and its application in railway train lighting technology. Specifically, it refers to using the combination of the Fresnel lens array and the reflective cup to collimate the light, and applying it to the headlights of railway trains. Background technique [0002] "LED Green Lighting and Its Non-imaging Optical Design" ("Physics Bulletin" No. 2, 2012) proposed a LED projection lighting system. At this time, the light source needs to have an efficient and collimated far-field distribution. Headlights, train headlights, flashlights, etc. The specific idea is to use LED chips at the front end, and use a combination of reflective cups and free-form Fresnel lenses at the rear end to collimate light. The paper proposes that light with a small angle can be collimated with a Fresnel lens, and light with a large angle can be collimated with a free-form surface reflector, and fin...

AI Technical Summary

Problems solved by technology

However, in the practical application of train headlights, this method still cannot make the light have a small divergence angle when performing remote lighting, and will cause part of the LED light to leak from the system and cannot produce sufficient remote illumination.

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