LED Optical Design And Application Research For Vehicle Signal Lamp

Automobile lamp system is not only a necessary device,but also an important part of driving safety.It can be divided into two categories according to their functions:lighting systems and signal systems.The main function of the signal systems is to show driving state of the vehicle,and then enable other drivers to clearly distinguish the signals for the safety feedback.At present,there are two main structures for most of the vehicle signal lights.One is based on bulbs and reflective cups,they have the disadvantages of low efficiency,large volume,uneven lighting,and so on.The other is multi-LED tile arrangement.They also have some shortcomings in the efficiency,size and appearance.In this paper,the key technology of LED vehicle signal light distribution is studied,and a new structure is designed and modularized to realize the high efficiency,compact structure,uniform lighting effect and other characteristics of the signal light.It mainly includes:1)A design method of free surface is proposed.Firstly,a reflecting surface is designed by combining paraboloid with the spherical surface with different parameters;And then,the free-form surface,obtained by arraying the spherical surface on the plane,can be applied to the surface of the external lens.So,the luminaire can meet the requirements of laws and have a more uniform lighting effect at the same time.2)A reflective-refractive LED collimating lens design is proposed,to realize collimated illumination during?3~?and improve the light utilization by combination of the refractive surface and the reflective surface.3)We propose a design method of a composite Fresnel lens with a four layer.The first layer directs the light emitted by LED in a direction perpendicular to the optical axis;The second layer uniformly distributes the outgoing light energy;The third layer collimates the light in the direction of the optical axis;The fourth layer disperses the collimated light to meet the regulations.By combining with different modules such as free-form surface,collimating lens and Fresnel lens,the design examples of three different function lamps are given that includes rear fog lamp,high position brake lamp and front turn indicator signal lamp.In addition,in order to meet the needs of the personalized development of new car signal lamp,this paper also proposes the method to design of the logo lamp and the welcome lamp.By designing a homogenizing lens and combining it with a diffusing lens and an outer lens,a logo lamp with uniform lighting effect is obtained.By using the designed parabolic reflector,parallel spherical lens group and aspheric lens,the LED welcome lamp can project different car signs,and have a good lighting effect.