Design Of A Novel Automatic Focimeter

The quantity of manufacture and consumption of spectacles is great in China and the quality of spectacles relates to the health of people. Focimeter, which is used for the optical parameter measurement of spectacles, guarantees the quality of spectacles production. Especially, the automatic focimeter is enjoyed by the spectacles stores for the reason that it is convenient, impersonal and multifunctional. But for a long time, such instruments have mainly been imported and domestic correlative technique lags. A novel automatic focimeter was designed when the principle of measuring the vertex power of spectacles and correlative documents had been studied.The background and significance of this project, knowledge relates to spectacles and focimeter were given firstly. Then the method adopted by the focimeter and the overall structure were analyzed. After that, the design of the hardware and software of the system were discussed a lot. Experiments and conclusion followed finally.By the action of the spectacles put in the instrument, the image of the parallel light which came through the Hartmann diaphragm would be transfigured. The instrument would recognize the type of spectacles, focus and find the highest power automatically based on the multiple-point measurement. The SOPC was adopted by the digital measurement and control system as main processing module and SOC as affiliate control module. The data from the image sensor was processed by the SOPC and the results as both figure and number were displayed on the LCD. In the mean time the LCD also used to guide to place the spectacles. 6 buttons and 1 speaker were designed. Thermal line printer was used to fit the fast measurement process. A technique that the system function could be modified by PC through the USB interface was designed to realize that there is no need to change the hardware to modify the system function. For the purpose of testing the high-speed system adopted BGA components, an online test was realized combined the USB interface and BSD technique.Experiments of the realized hardware and software showed that the precision is better than the national standard and the operation of the measurement process is convenient. The research of the project is practical.