Optical System For Automobile Headlamp Based On Laser Remote Activated Phosphor

Automotive headlamp's light source has been through the development from incandescent,Halogen lamp to Xenon lamp and LED,and laser diode,as the new generation of semiconductor light source,is more energy-saving because of the higher electro-optic conversion efficiency.As the production technology matures in the future,laser diode will become one of the main light sources for headlamp.Therefore,studying headlamp using laser diode as light source now will benefit the application of laser-lighting technology,which is forward-looking.In this paper,firstly,phosphor model is established in Light Tools according to Mie scattering theory.Then a light-guide is designed to accumulate the light from three laser diodes.After analyzing the reliability of light sources with transmissive and reflective structure,a laser white light source using remote activated phosphor with reflective structure is designed,and the quantitative impact of weight ratio of phosphor and silica particles are analyzed by simulation.Furthermore,the cooling structure for laser diodes and phosphor is designed and simulations confirm their reliabilities.According to structures mentioned above,a prototype of laser white light source is successfully made after fine tuning,and test result shows it can meet the requirement of being light source of headlamp.Next,using the simple and flexible meshing method,which contains the calculation of the coordinate mapping relationship between light source and target plane and the calculation and construction of freeform surface,two lenses are designed for high-beam and low-beam respectively.Optical simulation shows the distribution of illuminance and color temperature is qualified.Actual tests are run and the results show the headlamps can meet the requirements,proving the effectiveness of our design method.At last,using automotive lighting design software Lucid Shape,two Macro Focal Freeform Reflectors(MF reflectors)are designed for high-beam and low-beam respectively,and the test results in Lucid Shape show that the two reflectors can meet the requirements.The simulation in Light Tools,which contains the laser white light source,confirms the results in Lucid Shape,proving the MF reflector design method is suitable for our laser white light source.MF reflector is actually a good backup option for the freeform lens because reflector is dispersion free,in case high color uniformity is required.