投影距离可变的平视显示系统设计及优化  

Design and Optimization of a Head-Up Display System with Variable Projection Distance

作　　者：孙奕晗 吴慎将[1] 王波 陈晓伟 张一明 Sun Yihan;Wu Shenjiang;Wang Bo;Chen Xiaowei;Zhang Yiming(ISchool of Opto-Electronical Engineering,Xi'an Technological University,Xi'an 710021,Shaanxi,China;FORYOU Multimedia Electronics Co.,Ltd.,Huizhou 516006,Guangdong,China)

机构地区：[1]西安工业大学光电工程学院,陕西西安710021 [2]惠州市华阳多媒体电子有限公司,广东惠州516006

出　　处：《光学学报》2024年第8期182-198,共17页Acta Optica Sinica

基　　金：国家自然科学基金(61701385);西安工业大学研究生联合培养基金(XAGDYJ220202)。

摘　　要：设计了一种基于离轴反射式光学结构、投影距离可以改变的增强现实型平视显示(AR-HUD)系统,以降低驾驶员的视觉疲劳。其中,眼盒的大小为130 mm×50 mm,虚像投影距离为3~10 m,可以通过改变图像生成单元(PGU)到一级镜的距离和像源尺寸的方式实现投影距离连续可调。通过随机取样的方式,在投影距离变化范围内随机选取一个投影距离对系统进行像质分析,证明投影距离连续可变。视场角(FOV)在投影距离的可调范围内恒为15°×5°,畸变小于5%,动态畸变小于5′,MTF在5 lp/mm处优于0.5。结果表明,当车辆与前方物体距离较近时,AR-HUD系统可以根据需要改变虚像的投影距离,且能保证像质始终符合规格。Objective Head-up display(HUD)systems reduce driver visual fatigue and improve driving safety.Existing HUD only alleviates visual fatigue by reducing the times a driver looks at the dashboard.However,conventional augmented reality heads-up display(AR-HUD)system can usually only image at a fixed projection distance.When drivers approach an object,it is perceived that the image passes through the object.This causes drivers to constantly distinguish the distance between the object and the virtual image,which will lead to visual fatigue.Indeed,there is a need for a new type of HUD that makes the projection distance variable.Existing designs use an off-axis three-mirror system,by adjusting the position of the first mirror to achieve the projection distance variable.However,it will change the down angle and also need the picture generation unit(PGU)with variable angle of light output.This will increase the cost and design difficulty.It is necessary to study another way to realize the function of variable projection distance.Methods Unlike traditional co-axial zoom optics,for HUD with variable projection distances,changing focus is not the only way.Changing the object distance and size can also realize it.We use changing magnification to realize variable projection distance and only change the position and size of the PGU.This is because,like looking in a mirror,as the object distance is larger,the virtual image is farther away.Furthermore,the distance between the PGU and the first mirror decreases at the same time as the projection distance decreases.Since none of the images of PGU emitting by the way of parallel light,as the PGU is closer to the reflector,the image reflected by the mirror is smaller.As the projection distance decreases,the tensor angle of the virtual image relative to the human eyes decreases.This design does not cause the down angle to change,and there is no need to use the PGU with a variable angle of light output.The off-axis three-mirror system generally determines the initial structure by calcula

关 键 词：光学设计 平视显示器 光学变倍 投影距离 离轴三反系统 

分 类 号：U471[机械工程—车辆工程]