节点文献
头盔式近眼显示技术研究
Head Mounted Near-eye Display Technology
【作者】 杨敏娜;
【导师】 郭忠达;
【作者基本信息】 西安工业大学 , 光学工程, 2012, 硕士
【摘要】 头盔显示技术是近眼显示技术中的一种。它是一种安装在头盔上,给头盔使用者提供可视图像的微型显示装置,可以用于虚拟显示。本文研究了一种可使头盔使用者在观察外界情况的同时,也能获得头盔显示器中的可视图像信息,并且当使用者观察不同距离物体,进行视度调节时,可视图像始终在人眼中保持清晰的新型的头盔式近眼显示技术。首先,在视网膜投影显示光学系统的基础上进行研究,采用ZEMAX软件模拟设计优化了一套新的光学系统,该光学系统减少了透镜的数量,简化了系统的结构,增大了原光学系统中透镜的厚度、曲率半径和间隔,使光学零件易于加工且精度高,并且可以提高装配精度。本光学系统主要由激光扩束准直系统和滤波投影系统组成。系统采用光波波长为532nm的激光光源,扩束倍数为4倍,优化后的扩束准直系统在1.5mrad视场范围内波像差小于λ/4,光学传递函数在60lp/mm时达到0.9以上,艾里斑大小为4.367um-。滤波投影系统的镜目距为40mm,传递函数在60lp/mm时达到0.6以上。其次,对该视网膜投影系统的机械结构进行了设计。该系统为单目结构,整个光学系统放置于人眼的上方。该机械结构包括垂直调节、瞳距调节以及旋转调节等机构,实现了显示器的灵活移动。瞳距调节机构,包括37mm粗调和4mm微调,根据人手微调的灵敏度可确定粗调精度可达0.5~1 um、微调精度可达0.4~0.7um;垂直调节机构的调节范围是48 mm,调节精度可达0.5~1um;旋转机构可实现旋转角度都为11°的三维调节。最后,装配调试了视网膜投影系统的滤波投影系统,并用传递函数测量仪进行了传递函数的测试,测试结果为传递函数在60lp/mm时达到0.5以上本课题所设计的光学系统达到了设计要求,可以满足不同使用者的要求,瞳距调节机构可使显示器水平移动,满足不同人的瞳距要求,垂直调节机构可使显示器处于人眼前上下位置,旋转机构可实现三维方向转动。滤波投影系统的评价结果表明本系统基本可以实现其显示功能。
【Abstract】 Helmet display technology is a near-eye display technology. By being installed on a helmet-mounted, the helmet user can get the clear visual images. And also, it can be used in the virtual display. In this paper, we studied a new type of near-eye display technology. Which allows the users observe the outside world situation, and the user can get visual image information in the helmet-mounted display at the same time. When the user observed the different distance objects, visual images can always kept clearly in the eyes.In this thesis, we used a ZEMAX software to re-design a new set of optical systems on the basis of the existing retinal projection display optical system. The number of the lens, structure of the system, lens’s thickness, curvature radius and interval of the original optical system are changed, thus this optical system becomes simplify, therefore, optical parts can be easier processed and improved accuracy. The optical system mainly consists of the collimated laser beam expander optical system and the filter projection optical system. This system uses a wavelength of 532 nm laser as a light source, which is expanded by 4 times. We carried out the evaluation of image quality of optical system. The 1.5mrad visual field range within the wave-front aberration is less thanλ/4.The transfer function of spread collimation system is more than 0.9 at the OTF of 60lp/mm. AIRY DIAM size is 4.367 um. The last mirror to the eye distance of the filter projection optical system is 40mm. The OTF is above 0.6 at the OTF of 60lp/mm.In the subject, we designed the mechanical structure of the retinal projection system. The system is monocular structure. The entire optical system is placed in the top of the human eye. In order to move the display flexibly, the mechanical structure is dominated by the vertical adjusting mechanism, pupil distance adjusting mechanism, the rotating mechanism. Pupil distance adjustment mechanism can achieve the 37 mm course and 4 mm fine-tuning. According to the sensitivity of manual fine-tuning, the accuracy of the coarse is 0.5 to 1, fine-tuning from 0.4 to 0.7. The range of vertical adjustment is 48mm, then the vertical adjustment accuracy is 0.5 to 1; The rotating mechanism can achieve three-dimensional rotation, the rotation angle is 11°. In this article. The filter projection optical system of the retinal projection system is to be assembled and debuged. The OTF measurement tested the installed system. The result is 0.5 at the OTF of 60lp/mm.The optical system of this project design meets the design requirements. The structure can meet the requirements of different users. Pupil distance adjusting mechanism allows the monitor to move horizontally. The vertical adjustment mechanism allows the display to move up and down in front of the eyes. The rotating mechanism can be three-dimensional direction of rotation. The evaluation results of the filter projection optical system show that the system can basically display.
【Key words】 retinal projection display; optical design; laser; LCD; structural desig;