Research Of Inspection System For Phoropters

Phoropter is a comprehensive optometry instrument that can mechanically replace lenses to achieve refractive examination functions.The main measurement performance indicators of phoropter are spherical lens top focus,column lens top focus,column lens axis position and center error,etc.In the process of production,assembly and use of phoropter,its performance indicators may change,which will lead to inaccurate optometry.Therefore,it is crucial to ensure high-quality inspection and control measurements for phoropters.This paper researches a phoropter inspection system based on the selfcollimating clarity method,which can effectively improve the fixation accuracy and thus the measurement accuracy,Moreover,it increases the complexity of the task of designing and assembling optical systems.The system adopts the folding optical path to achieve the overall miniaturization of the equipment,The linear displacement sensor is used to measure the moving distance of the concave mirror,the angle encoder is used to measure the rotation angle of the target reticle,and the CCD is used to collect the target image.The computer system is used to measure and analyze the data.Then,the structural design of the phoropter testing system is completed,the corresponding photoelectric parameters are given,and the measurement methods for various performance indicators of the phoropter are analyze.And based on the dynamic optics theory,By taking into account the actual system conditions,we studied variations in the optical path and utilized a modular assembly approach to successfully construct the initial working prototype based on these findings.and the instrument is traceable to the national standard of top focal length.Finally,To safeguard the precision of the test results of the phoropter testing device,experimental verification of repeatability and experimental verification of measurement accuracy were conducted,and the uncertainty of the system was analyzed.The theoretical analysis and experimental results show that the extended uncertainty of the top focal length of the spherical lens can reach(0.03～0.08)m-1(k=2)when the device is used to test the phoropter,which meets the requirements for the verification of the phoropter.