LI Can, SONG Shu-mei, LIU Ying, LI Chun, LI Xiao-hu, SUN Qiang. Design of optical system for catadioptric fundus camera[J]. Editorial Office of Optics and Precision Engineering, 2012,(8): 1710-1717
LI Can, SONG Shu-mei, LIU Ying, LI Chun, LI Xiao-hu, SUN Qiang. Design of optical system for catadioptric fundus camera[J]. Editorial Office of Optics and Precision Engineering, 2012,(8): 1710-1717 DOI: 10.3788/OPE.20122008.1710.
Design of optical system for catadioptric fundus camera
To eliminate the scatter light and central ghost in a classical fundus camera
the optical system of a catadioptric fundus camera with a field of view 40? and a working distance of 48 mm was designed. An off-axial reflecting ophthalmic lens with free form surfaces was designed to correct the off-axial aberrations. Two free-form-surfaces were introduced in the imaging objective system to correct the residual off-axial aberrations of the reflective ophthalmic lens. In the optimization of the imaging system
an eye model with varying defocuses was proposed to eliminate the negative effect of eye aberrations as well as to accommodate the eye with different refractive errors. Three adjacent illumination rings were introduced in the illumination part to avoid the undesirable light reflected by the eye optical system. Experiments show that the accommodation range of the system is between -10 m
-1
and 10 m
-1
the resolution at the object plane is 33 lp/mm across the entire field of view
and the maximum distortion is less than 8.5%.Furthermore
the illumination non-uniformity is less than 15% in the conditions without scatter light and central ghost. The designed catadioptric fundus camera with a free-form-surfaces show a satisfactory large field of view and a large working distance
and removes the undesirable scatter light and central ghost greatly.
关键词
Keywords
references
李淳,孙强,刘英,等. 眼底相机的均匀照明及消杂光干扰设计[J]. 中国光学, 2010,3(4):363-368. LI C,SUN Q,LIU Y, et al.. Design of uniform illumination system of fundus camera and its stray light shield [J]. Chinese Optics,2010,3(4):363-368. (in Chinese)
崔桂华. 眼底照相机光学系统中杂光和鬼像的控制[J]. 光电技术,2006,26(2):139-141. CUI G H. Control of ghost and scatter light internal camera [J].Opt.Technique,2006,(26):139-141.(in Chinese)
DELORI F C, PFLIBSEN K P. Spectral reflectance of the human ocular fundus[J]. Applied Optics,1989,28(6):1065-1077.
DEHOG E,SCHWIEGERLING J. Optimal parameters for retinal illumination and imaging in fundus cameras [J]. Applied Optics, 2008,47(36):6769-6777.
BUCHHEISTER J,MUELLER L. Reflex free double pass objective due to reflective free form surfaces[J]. SPIE,2008,7100 (71000N-1):1-10.
SHIBATA N, TORII M. Fundus camera:USA, 6654553 .2003-8-1.
姜洋,孙强,谷立山,等. 折/衍混合自由曲面式头戴显示器光学系统设计[J] . 光学 精密工程, 2011,19(3):508-514. JIANGY,SUN Q,GU L SH, et al..Design of optical system of HMD using hybrid refractive/diffractive and free-form surfaces[J]. Opt.Precision Eng., 2011,19(3):508-514.(in Chinese)
赵清亮,郭兵,杨辉,等. 金刚石飞切加工微结构表面的表面粗糙度研究[J]. 光学 精密工程,2009,17(10):2512-2519. ZHAO Q L,GUO B,YANG H, et al.. Surfaces roughness study in diamond fly-cutting of micro-structured surface[J].Opt. Precision Eng.,2009,17(10):2512-2519.(in Chinese)
张以谟.应用光学[M]. 北京:电子工业出版社,2008. ZHANG Y M.Applied Optics[M].Beijing:Publishing House of Electronics Industry,2008.(in Chinese)
王肇圻,王尧,全薇. 基于眼模型的非球面眼底荧光相机的设计[J]. 光学 精密工程, 2010,18(7):1511-1519. WANG ZH Q,WANG Y, QUAN W.Design of aspheric FFA camera based on eye model[J].Opt.Precision Eng., 2010,18(7):1511-1519.(in Chinese)
王肇圻,许妍. 基于眼模型的数字眼底相机设计[J]. 光学 精密工程,2008,16(9):1567-1571. WANG ZH Q,XU Y.Design of digital retina camera based on eye model[J].Opt.Precision Eng., 2008,16(9):1567-1571.(in Chinese)
MOUROULIS P. Visual Instrumentation[M]. New York:McGraw-Hill,1999:106-110, 277-280.
NAOKI I, MAKIHIRO I.Fundus Camera:USA, 2009/0180073A1 .2009-7-16.
DEHOOG E,SCHWIEGERLING J.Fundus camera systems: a comparative analysis[J]. Applied Optics,2009,48(2):221-228.