Research On Key Technology Of Waveguide Head-Up Display Based On Microprism Structure

In recent years,as people pay more attention to the issue of road traffic safety,the vehicle head-up display system with augmented reality function has received extensive attention as a safe driving assistance device.However,the current vehicle head-up display system is mainly based on a free-form surface optical projection system,and the overall volume is large,and it is difficult for most models to provide enough installation space.At this time,the waveguide display technology has demonstrated its application potential in the automotive field by virtue of the characteristics of miniaturization and light weight,but the existing waveguide display technology still has shortcomings in the application process.Under this circumstance,this paper has carried out the following work for the application of waveguide display technology in the field of vehicle head-up display:1.The working principle of the vehicle head-up display system and three mainstream system design schemes are introduced in the thesis.Firstly,the working principle and performance parameters of the system under different design schemes are explained in detail,and the limitations of the existing design schemes under the requirement of high integration are pointed out.Then,the advantages of waveguide display technology in realizing system miniaturization and light weight are pointed out,and the working principles and research status of traditional geometric optical waveguides and diffractive optical waveguides are introduced in detail.Finally,the shortcomings of the two schemes in mass processing and full-color imaging display are pointed out respectively.2.The design of the waveguide head-up display system based on the microprism structure is completed in the thesis.Firstly,the basic theory of waveguide structure design is deduced according to the propagation law of light beam in the waveguide,and the specific waveguide structure parameters can be calculated according to the design requirements of system performance parameters.Then,the problems of stray light,missing image,and uneven energy distribution in the waveguide imaging display are analyzed in detail,and these problems are effectively solved by limiting and optimizing the parameters of the waveguide structure.Finally,according to the actual requirements of the vehicle-mounted system with a field of view of 10° × 5° and an eyebox of 130 mm × 50 mm,the waveguide structure is designed and completed,and a simulation model is established to analyze the imaging display results of the system.The simulation results show that the illumination uniformity of each field of view of the system is greater than 64%,which effectively eliminates stray light in the observation range,and full-color display can be realized,which verifies the feasibility of the waveguide display technology based on the microprism structure,and the system volume is less than 11 liters.3.The fabrication and verification experiments of the waveguide head-up display system based on the microprism structure are completed in the thesis.Firstly,the fabrication of the microprism structure was completed by three processing schemes: UV-curing nanoimprinting,contact printing and diamond lathe turning,The structure size,microstructure consistency and surface roughness of the obtained microprism structure were measured and analyzed.Then build an experimental platform to quantitatively detect and analyze the actual field of view,eyebox,resolution,brightness and full-color display results of the system.The final experimental results show that the system can realize full-color imaging display,which verifies the correctness of the design theory and simulation analysis of the waveguide head-up display system based on the microprism structure.