Study On The Process Test Of Fast Focusing Liquid Lens Device

With the development of zoom technology,since the advent of liquid lens with its good scalability and optical performance.It has great potential and advantages.Recently,fast focusingperformance has gradually become an important technical indicators of liquid lens applications,but the liquid lens how to achieve fast focusing is still difficult to study and hot spots.In this paper,the process test of fast focusing liquid lens devicedrived by high-frequency acoustic wavehas been studied.Firstly,the resonance theoretical model of fast focusing liquid lens is established.By calculating the change of the peak displacement of the spherical crown,The natural frequency of the liquid lens is combined with the excitation frequency of the sound source so that the liquid lens achieves resonance by means of an external acoustic field excitation.The influence of spherical volume,substrate thickness and pore size on the natural frequency was obtained by fitting the theoretical mode.According to the optical theory of biconvex lens,the focal length formula of fast focusing lens is deduced,and the range of focal length under specific process parameters is predicted.By using the method of separation coupling modeling and the approximation of the equivalent liquid lens surface tension of the elastic thin film,the transmission and interaction of forces and displacements are realized by numerical simulation.The liquid lens model is analyzed by fluid-structure coupling.It is found that the influence of different process parameters on the natural frequency of the lens is basically the same as the theoretical analysis.Secondly,based on 3D printing technology to produce fast focusing liquid lens deviceand design process test program.The response frequency,amplitude and zoom rate of the high-speed zoom lens were measured by laser Doppler velocimetry.The response frequency,amplitude and zoom rate of the fast focusing liquid lens at different driving frequencies were measured by laser Doppler vibrometer.By analyzing the experimental data,the influence of process parameters on the fast focusing liquid lens device is obtained.The experimental results show that the influence of the above parameters on the resonant frequency of the liquid lens is in good agreement with the theoretical and simulation results.Finally,in order to further study the imaging effect of the fast focusing liquid lens device in specific focal length range,combined with the resonance characteristic test data and the high-speed camera is used for image acquisition experiment.Experimental image acquisition sequence by Canny edge sharpness evaluation function of MATLAB toolbox for image processing.The results show that the fast focusing liquid lens device has better imaging effect and higher zoom rate in the focal length range.On the basis of the above test scheme,by changing the focal length(in the specific focal length range),the substrate thickness and the aperture size,get the influence of different process parameters on the imaging effectwas obtained.