成像角膜曲率计的光学设计

为了提高角膜曲率计的测量精度,借助于现代光电子技术,设计了一款高精度的成像角膜曲率计.系统包括环形物、一次成像系统、角膜、二次成像系统和CCD探测器.首先在ZEMAX软件中,设计了成像角膜曲率计的一次成像系统和二次成像系统,分别对两个成像系统进行优化设计;然后通过半透半反镜组将一次成像系统和二次成像系统拼接,组成成像角膜曲率计的光学系统,并对其进行整体的优化设计.最后,利用TracePro对所得的环形像进行模拟和分析.结果表明:所设计的成像角膜曲率计的测量范围约为30~60D(对应角膜曲率半径5.5~11 mm),测量精度在角膜曲率半径7.8 mm时达到0.072D.

Optical design of imaging keratometer

An imaging keratometer by the aid of modem optoelectronic technology is proposed to improve the accuracy of measurement. The optical system consists of an annular object, a first imaging subsystem, a sec- ond imaging subsystem, and a CCD detector. First, the first imaging subsystem and second imaging subsystem are designed and optimized by ZEMAX, and two subsystems are connected by a semitransparent mirror. Then we perform optimization of the whole optical system of imaging keratometer. Finally, the simulation of the iXlu- ruination of the annular image is accomplished by TracePro. The result shows that the measurement range of this imaging keratometer is about 30D to 60D（5.5 mm to 11 mm in radius of curvature）, and the accuracy is about O. 072D in the case of the radius of curvature of 7.8 mm.