Three Dimensional Scanning Control System Of Laser Differential Confocal Microscope

Confocal microscopy has excellent lateral resolution and unique axial tomographic capabilities,making it an increasingly important role in the field of non-contact imaging detection.However,it also has some defects such as low linearity,low sensitivity and low axial resolution near the focus.Meanwhile,the structure and function of the precision components become increasingly complex with the improvement of science and technology,which poses great challenges to the detection equipment.The existing confocal microscopy can no longer meet the urgent needs of high-resolution imaging detection.On the other hand,the optical detection imaging technology based on laser differential confocal technology has become one of the main methods in the field of detection by the characteristics of lateral optical super-resolution and axial nanometer resolution and is easy to realize digitized 3D imaging.In order to realize high resolution and high speed detection of three-dimensional morphology of micro objects,we first need to study the three-dimensional scanning system of the laser differential confocal microscope.The research content of this project was carried out on the project of "high spatial resolution laser differential confocal Raman spectroscopy LIBS mass spectrometric measurement and morphological imaging method research".It is the goal of this subject to realize high precision and high speed imaging of laser differential confocal microscopy.It studied the 3D scanning control system to enhance the speed and accuracy of the control system.By authoring the software,the scanning system was controlled to drive the tested sample to move in three dimensions.And combined with the data acquisition function,three-dimensional imaging of the sample under test was achieved.The main research content of the paper includes:1.The basic principle of laser differential confocal microscopy imaging system was carefully studied and the importance of the precision of the 3D scanning system was highlighted.Combining the development status of the three-dimensional microscope scanning system at home and abroad,piezoelectric ceramics were selected as scanning drivers for 3D scanning system of laser differential confocal microscope;2.The working principle of the piezoelectric ceramic actuator was studied.The driving power,the piezoelectric ceramic driver and the worktable of the piezoelectric ceramic micro displacement system were respectively modeled with the PID control theory.to study the transfer function of the micro-displacement system.A high-duty cycle analog control drive waveform was designed according to the mathematical model of the piezoelectric ceramic micro-displacement system to achieve both the standards of accuracy and speed of the system;3.The author designed the software structure of the three-dimensional scanning control system of laser differential confocal microscope,wrote the software program and analyzed the tomographic scan mode on the basis of transverse scan control and the point scanning mode on the basis of the axial scan control.In term of the principle of microsystem imaging and the characteristics of the objective lens driver,a new point scan control mode was designed to reduce the system imaging time;4.The advantages of the new point scanning mode were verified through the test of the axial differential response curve of the micro system.The reliability of the piezoelectric ceramics was tested by the oscilloscope.And the three-dimensional imaging of the samples was carried out by the tomography mode and the point scanning mode respectively.