设计的透镜中心厚度测量系统是一种基于色差共焦原理、能快速自动测量且不接触透镜表面的新型测量系统。为使得测量设备测量范围较大，采取建立多重结构的方式分别消除各个组态内的单色像差，并放大组态间像距的差值以增大系统的位置色差。所设计的光学系统在400～1000 nm 波段范围内产生30 mm 左右的位置色差。使用该光学系统，能使测量设备的最大测量范围达到30 mm 以上。利用研制的设备对3 种不同厚度的透镜进行了实际测量，结果表明：对于厚度为6、15、30 mm 的透镜，设备的测量精度分别为±2.5、±3.5、±5.0 μm。

The designed lens central thickness measuring optical system is a kind of new system based on chromatic confocal principle, which can fast and automatically measure center thickness of lens without contact of lens surfaces. In order to expand measuring range of device, multiple configuration modes are established to eliminate monochromatic aberrations within each configuration, and enlarge the D- value of image distance to increase the longitudinal chromatic aberration. In this way, the longitudinal chromatic aberration of the system can reach about 30 mm in the wavelength range from 400 nm to 1000 nm. The maximum measurable lens thickness can be more than 30 mm by using this optical system. Measurement of three different lenses whose central thicknesses are 6, 15 and 30 mm is done. The results show that the measuring accuracies for the three lenses are ±2.5, ±3.5 and ±5.0 μm.