Mobile Phone Screen Detection Based On Balanced Spectral Domain Optical Coherence Tomography System

In modern society,smart phones have covered all aspects of life.We can't do without mobile phones in many application scenarios,and human-computer interaction is realized in smart phones.As a mobile phone screen connecting users and smart phone windows,it is a smart phone.One of the most important components of development to date.The advantages and disadvantages of mobile phone screens have a huge impact on the production of screens and the user experience,so how to find a relatively fast and accurate way to detect mobile phone screen defects is a common problem faced by today's screen and mobile phone manufacturers.At present,the defect detection of mobile phone screens is mostly done manually,which has a great influence on the efficiency and accuracy of detection.For this reason,we propose to use the frequency domain optical coherence tomography method to detect the screen of the mobile phone.We use the balanced spectral domain optical coherence tomography system in the laboratory to detect the screen of mobile phones.The paper first expounds the research background and significance of 3D contour measurement,and introduces several methods of contour measurement.Then we mainly introduce the balanced spectral domain optical coherence tomography system(BD-SDOCT,hereinafter referred to as BD-SDOCT),which introduces the optical path principle of BD-SDOCT in detail,and spends more time.The space describes the hardware components of the entire optical system and the role of each hardware.In order to let the readers clearly understand the system,we introduce the system into three main parts when introducing the system: 1.Light source and collimation module;2.Balanced Michelson interference module;3.Spectrometer module.After introducing the optical path principle and hardware of the system,we also focused on the mathematical principles of wave-number scanning interference and BD-SDOCT measurement,focusing on the feasibility of the contour measurement system.Before the final measurement of the mobile phone screen,we conducted experiments with glass slides and epoxy materials to ensure that the system can work normally.When measuring experiments on slides and epoxy resin,we found that the two channels The system can make the effective signal in the experimental results stronger than the single channel,and also has a good inhibitory effect on the noise signal.We compare the measured results of the mobile phone screen with the dismantling structure of the mobile phone screen.In the experimental results,we can clearly observe the front and rear surfaces of the glass cover layer and the front and back surfaces of the optical adhesive layer(since the optical adhesive is a layer A very thin,high-transmitting gel-like substance,the interference signal and the glass cover signal and the polarizer signal are superimposed to some extent),the front and back surfaces of the polarizer,and the front and back surfaces of the capacitive touch layer.Experiments have shown that the optical coherence tomography method can be used to detect the smartphone screen,and the BD-SDOCT system built in the laboratory can achieve deeper multi-layer surface measurement when measuring the screen of the mobile phone.