Research And Application Of Microprism Angle Error Measuring System

Reflective film has good retroreflective performance,can reflect the light incident into it back in the anti-parallel direction,and it has very good visibility.Because this material is designed to be easy to use,energy-saving,environmentally friendly,reliable and durable,and low in cost,it is currently widely used in various industries such as transportation,clothing,and advertising.Manufacture of high-grade reflective film has very high technical requirements for materials,molds and processes,including the surface roughness of the microprism structure inside the master mold and the accuracy of its angle,both of which have a direct impact on the reflective performance of the reflective film.With the increasing market demand for high-grade reflective films,there is an urgent need to propose a new microprism angle error measurement method to improve its angular accuracy,improve the processing accuracy of the master mold,and thereby improve the reflectivity and reflective performance of the reflective film.At present,domestic manufacturers of micro-prism reflective film mainly use conventional confocal microscope image recognition methods to measure the angle error of micro-prisms,but this method is too low in detection efficiency,and it is difficult to meet actual measurement requirements.Therefore,a set of rapid and accurate measurement methods for the angle error of microprisms is of great significance for the production of high-performance microprism reflective films.Based on the measurement principle of the corner prism angle error,combined with the light reflection principle and structural characteristics of the micro prism,the optical measurement model of the micro prism angle error is first established,and the laser autocollimator measurement system based on the self-collimation measurement principle is built.Complete the measurement of the angle error of the microprism.By designing the tooling,displacement and angle adjustment frame of the laser autocollimator measuring device,the clamping and position adjustment of the optical components of the measuring device are realized.By designing a double-lens focusing system to ensure that the laser auto-collimation measurement system can complete the measurement of the micro-prism’s tiny angle error.The programming of the measurement system data acquisition program,graphic display and data storage program and filter program are completed through Labview graphical programming software.Before the measurement experiment,the laser autocollimator measurement system was tested for sensitivity calibration and stability measurement.The experimental data showed that the laser autocollimator built in this paper has a range of ±100″ in the yaw angle and pitch angle.The calibration residuals are within ±1.4 " and ±1.2",and the drift within 40 minutes is within 1.2 " and 0.8",respectively.The data shows that the laser autocollimator system has good stability and high measurement accuracy.Finally,the measurement system is used to achieve the measurement of the angle error of the microprism reflective array.The experimental results show that compared with the conventional confocal microscope image recognition measurement method,the measurement system has higher measurement efficiency and the measurement accuracy can meet the actual measurement requirements.