| The geometric parameters,such as the thickness of the glass sheet,the out-diameter and wall-thickness of the glass tube and the sizes of the bubbles in the glass,etc.are the im-portant technical indexes of a product.Geometric heterogeneity is also an important factor causing local crystallization of glass.On-line measurement of geometric parameters is con-ducive to timely feedback of measurement results to adjust thermal parameters.The present laser detection methods can not effectively eliminate the measurement errors caused by in-cident angle fluctuation and other factors.Therefore,it is of great significance to improve the measurement accuracy of geometric parameters by improving and optimizing the opti-cal configuration to eliminate or suppress errors.This paper focuses on the laser detection method of glass geometric parameters.The main contents are as follows:Firstly,the thickness measurement method based on the laser triangulation is improved,an auxiliary beam tilt correction scheme for direct laser triangulation thickness measurement is proposed,and an oblique laser double triangulation thickness measurement mathematical model is established.The thickness measurement method based on the laser transmission is enhanced,the influence of thickness and refractive index on lateral deviation of trans-mission beam is analyzed and a double path transmission thickness measurement scheme is proposed.The thickness measurement method based on the laser reflection is optimized,the influence of thickness and refractive index on the reflected double beam spacing is ana-lyzed,and the best angle of incidence is determined.The linear structure laser reflection-type glass thickness measurement experiment system is established and the error sources and im-provement measures are analyzed.A double path reflection thickness measurement scheme is proposed.Based on the method of transmission and reflection thickness measurement,a scheme of transmission-reflection-type thickness measurement is presented,and the best angle of incidence is determined.The transmission-reflection-type thickness measurement experiment system is established for the verification of error suppression effect.Secondly,aiming at the limitation of geometrical optics on the thickness measurement of ultrathin glass,based on the linear frequency modulation laser with Doppler galvanometer or via current,the double beam and multiple beam heterodyne glass thickness measuremen-t method is refined.Simulative experiment on the thickness measurement of the substrate glass used for ultrathin display is carried out for the analysis of thickness measurement pre-cision.Thirdly,in the light of the theory of geometrical optics and Fresnel formula,when the parallel light irradiates the glass tube vertically,the distribution law of the deviation angle and intensity of the transmission beam with the off-axis distance of the incident beam is the-oretically derived.The principle of rotating mirror and vibrating mirror scanning of narrow laser beam is introduced and a method for on-line measuring the outer diameter and wall thickness of glass tube by the laser scanning type is proposed.Based on CCD imaging prin-ciple,enlarging laser transmission imaging method which is used for measuring the outer diameter and wall thickness of glass tube on line is put forward and the mathematical mod-el of the outer diameter and wall thickness measurement is established.According to the bilateral telecentric light path,a lens that receives transmitted light is designed.Based on the enlarging laser transmission imaging method,Experimental system used for measuring the outer diameter and wall thickness of glass tube is set up for the analysis of measurement precision and error sources.Finally,according to the two dimensional imaging principle of the linear structure laser scanning the glass bubble,the matching relation between the pixel clock frequency and the laser scanning speed is deduced.The cause of bubble image distortion is analyzed.The line structure laser scanning glass bubble size vision measurement system is established for the analysis of measurement precision of the transverse and longitudinal size of bubbles in a glass sheet.Far field interference problem for the scattered light beam from the glass bubble irradiated by parallel beam is discussed.The distribution law of the optical path difference and relative intensity of far field interference is deduced.The optimum observation angle used for the bubble diameter measurement is given via numerical simulation. |
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