A new type of coaxial ultra short focal projector was designed in order to reduce the alignment difficulty
reduce the difficulty of system design and shorten the total length. Firstly
by analyzing the relationship between the system's total length and the aberration
the necessity of ensuring a long system's total length is proved. Then
through hollowing the central portion of an aspherical mirror and using a plane or spherical mirror to deflecting the optical path
a new design method for ultra short focal length projector is presented. It solves the blocking problem existing in the coaxial catadioptric optical system and improves the space utilization rate by ensuring a long total optical length and shortening the overall machinery length. Finally
the system's screen size is 100 in and the total length of 215 mm. The focal length is 1.66 mm and the object NA is 0.2 with 0.17 throw ratio. The MTFs of every field are over 0.5 at the Nyquist Frequency. All of the indexes meet the demand of the projective system. Meanwhile
in the case of the same number of lenses
the system's performance is better than the conventional projector.
关键词
Keywords
references
赵星,吴宏超,宋丽培,等.微型投影机自由曲面LED聚光器的设计[J].光学精密工程,2010,18(10):2124-2128. Zhao X, Wu H C, Song L P, et al. Design of freeform LED concentrator for micro-projector[J]. Optics and Precision Engineering, 2010,18(10):2124-2128. (in Chinese)[2] 马建设,张波常,苏萍,等.应用微柱透镜的自由立体前投影屏幕设计[J].液晶与显示,2013,27(6):760-763. Ma J S, Zhang B C, Su P, et al. Autostereoscopic front projection system based on micro-lenticular lens array[J]. Chinese Journal of Liquid Crystals and Displays, 2013, 27(6):760-763. (in Chinese)[3] 康玉思,田志辉,刘伟奇,等.激光显示广角球幕投影镜头设计[J].液晶与显示,2013,28(3):330-337. Kang Y S, Tian Z H, Liu W Q,et al. Wide-angle dome-screen projection lens design of laser display[J]. Chinese Journal of Liquid Crystals and Displays, 2014, 29(3):333-336. (in Chinese)[4] Yang J M, Liu W Q, Lv W@Z, et al. Method of achieving a wide field-of-view head-mounted display with small distortion[J].Opt. Lett. 2013,38(12):2035-2037[5] 卢海平,刘伟奇,康玉思,等.超大视场头盔显示光学系统设计[J].光学精密工程,2012,20(5):979-987. Lu H P, Liu W Q, Kang Y S, et al. Design of compact optical system in wide-angle head mounted display[J]. Optics and Precision Engineering, 2012, 20(5):979-987. (in Chinese)[6] Kuwata M, Sasagawa T, Kojima K, et al. Wide angle projection optics for compact rear projector[J]. SID'05 Digest, 70(3):1918-1921.[7] Gohman J A. Wide-angle projection lens[P]. U.S. Patent 7175287_2007.[8] Ogawa J, Agata K, Sakamoto M, et al.Super-short foeus front projectior with aspheric mirror projection optical system[J]. SID'05 Digest, 13(2):111-116.[9] 孙旭涛.应用自由曲面的超薄投影显示系统理论和实验研究[D]. 杭州:浙江大学,2008. Sun X T. Application of free-form surface of ultra-thin projection display systems theory and experimental research[D]. Zhejiang:Zhejiang University, 2008(in Chinese)[10] Shikama S, Suzuki H. Optical system of ultra-thin rear projector equipped with refractive-reflective projection optics[J]. SID 02 Digest 46.(2)1250-1253.[11] 康玉思,田志辉,刘伟奇,等.超薄前投激光显示系统研制[J].应用光学,2012,33(5):832-836. Kang Y S, Tian Z H, Liu W Q, et al. Ultra-thin front projector for laser display system.[J]. Journal of Applied Optics, 2012, 33(5):832-836. (in Chinese)[12] 李丹,薛芸芸,曹雯,等.基于微透镜阵列的DMD芯片投影系统照明优化[J].光学学报,2013,33(1):0122002-1-0122002-4. Li D, Xue Y Y, Cao W, et al. Optimization of DMD illumination system with microlens array[J]. Acta Optica Sinica, 2013,33(1):0122002-1-0122002-4. (in Chinese)