Mechanism design of focal output for zoom lens
-
摘要:根据光学设计中变倍组与补偿组的移动量与系统焦距的关系,设计了一种在变焦距镜头连续变焦时能准确输出焦距值的结构。该结构由蜗轮蜗杆驱动,以直线位移传感器为反馈元件,采用一个连接杆将直线位移传感器与变焦镜组进行固定连接来保证镜组的移动量直接反馈为位移传感器的电压值。与传统的通过齿轮传动将焦距变化反馈到旋转电位器的结构相比,该结构消除了由齿轮传动的空回、凸轮带动钉的间隙以及电位器的误差值等带来的影响。精度分析表明,采用这种高精度的直线位移传感器,加在其上的电压的变化可直接换算成焦距的变化,因此提高了焦距输出的精度。Abstract:A mechanism structure for the focal output of a zoom lens in varifocusing process was designed based on the relation of system focus, variable magnification unit and compensation unit in the optical design. A line displacement sensor was taken as feedback, a worm wheel and a worm as drive-elements in the mechanism structure, and a joint pole was adopted to fix and join the high-precision line displacement sensor and the zoom lens, so that the motion values of zoom lens was directly feeded back to the voltage of line displacement sensor. As compared with traditional mechanism structure that the focal-length was calculated by the relation of the cam rotational angle acquired by gear-driven potentiometer, the precision was low for the last motion error of gear, clearance of cam, drive nail and the potentiometer error. The results of precision analysis show that the focal-length can be obtained immediately based on the voltage of line displacement sensor which reflectes the displaces of zoom lens, therefore the precision for focal output is improved greatly.
-
Key words:
- zoom lens/
- structural design/
- focal length/
- precision
-
[1] 胡家升.光学工程导论 [M].大连:大连理工大学出版社,2002. HU J SH.Introduction to Optical Engineering[M]. Dalian:Dalian University of Technology Press, 2002. [2] 王平,张葆,程志峰,等. 变焦距镜头凸轮结构优化设计[J]. 光学 精密工程 ,2010,18(4):893-898. WANG P,ZHANG B,CHENG ZH F,et al.. Optimal design of cam structure of zoom fens[J].Opt. Precision Eng.,2010,18(4):893-898.(in Chinese) [3] 李永刚,张葆,丁金伟. 红外连续变焦镜头的结构设计[J]. 长春理工大学学报 (自然科学版),2009,32(1):60-63. LI Y G,ZHANG B,DING J W. Mechanism design of continuous infrared zoom lens[J].J. Changchun University Sci. and Technol.(Natural Science Edition),2009,32(1):60-63.(in Chinese) [4] 史亚莉,王一凡,宋春鹏,等. 连续变焦距镜头焦距实时输出问题研究[J]. 仪器仪表学报 ,2006,27(6):50-52. SHI Y L,WANG Y F,SONG CH P,et al.. Active focal length output of zoom lens[J].Chinese J. Sci. Instrument,2006,27(6):50-52.(in Chinese) [5] 王一凡,薛育. 一种大口径高精度凸轮变焦机构的设计[J]. 光学 精密工程 ,2007,15(11):1756-1759. WANG Y F, XUE Y. Design of heavy calibre and high precision cam-varifocal mechanism[J].Opt. Precision Eng.,2007,15(11):1756-1759.(in Chinese) [6] 崔继承. 大口径折反射式变焦距物镜的设计[J]. 光学 精密工程 ,2008,16(11):2087-2091. CUI J CH. Design of large aperture refractive-reflective zoom lens[J].Opt. Precision Eng.,2008,16(11):2087-2091.( in Chinese ) [7] 田海霞,杨建峰,马小龙. 可见光变焦距电视光学系统设计[J]. 光子学报 ,2008,37(9):1797-1799. TIAN H X,YANG J F,MA X L. Design for visible video zoom optical system[J].Acta Photonica Sinica,2008,37(9):1797-1799.(in Chinese) [8] 陈志坚,杨小君,李哲. 高速电视测量仪中精密变焦系统控制方法的研究[J]. 科学技术与工程 ,2007,7(13):3145-3148. CHEN ZH J, ANG X J,LI ZH. Study on the methods of control and calibrated focal length in high-speed TV measurement instrument[J].Sci. Technol. Eng.,2007,7(13):3145-3148.(in Chinese)
点击查看大图
计量
- 文章访问数:5113
- HTML全文浏览量:547
- PDF下载量:2244
- 被引次数:0