【作者】 李建军；

【导师】 石广丰；

【作者基本信息】 长春理工大学 ， 机械工程， 2017， 硕士

【摘要】 随着变焦技术的快速发展,液体透镜展现出了良好的可变焦性和光学性能,并具有巨大的潜力和优势。目前,高速的变焦性能逐渐成为液体透镜应用的一项重要技术指标,但如何实现液体透镜高速变焦仍为研究的难点和热点。本文针对高频声波驱动的高速变焦液体透镜装置开展了工艺试验研究。本文首先建立了高速变焦液体透镜共振理论模型,采用计算液体透镜球冠顶点位移改变量的方法,将液体透镜固有频率与声源激励频率相结合,通过外加声场激励的方式实现共振。通过分析得出球冠体积、基板厚度和孔径大小对固有频率的影响规律。根据双平凸透镜光学理论,推导出高速变焦液体透镜焦距公式,并预测出特定工艺参数下的焦距变化范围。基于数值模拟技术,采用分离耦合建模以及弹性薄膜近似等效液体透镜表面张力的方法,实现力与位移的传递和交互,完成了对液体透镜模型进行流固耦合模态分析,得出不同工艺参数对液体透镜固有频率的影响规律,所得规律与理论分析结果基本一致。其次,基于3D打印技术制作了高速变焦液体透镜装置,设计了高速变焦液体透镜装置工艺试验方案。采用激光多普勒测振仪测量高速变焦液体透镜在不同驱动频率下的响应频率、振幅及变焦速率,通过分析试验数据得到了工艺参数对高速变焦液体透镜装置一系列影响规律。试验结果表明上述工艺参数对液体透镜共振频率的影响规律与理论及仿真分析结果基本吻合。最后,为进一步研究特定焦距范围的高速变焦液体透镜装置的成像效果,结合共振特性试验数据,采用高速相机进行图像采集试验。试验采集图像序列通过MATLAB工具箱自带的Canny边缘清晰度评价函数进行图像处理,所得结果验证了在该焦距范围内,高速变焦液体透镜装置具有较好的成像效果和较高的变焦速率;在以上试验方案的基础上,通过改变焦距(特定焦距范围内)、基板厚度以及孔径大小,得到不同工艺参数对成像效果的影响规律。更多还原

【Abstract】 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.更多还原