Research On MEMS Micromirror For Laser Display

The MEMS micromirror can project the colored light beam onto the screen through the scanning and reflection,and it is the core of light beam scanning device in laser scanning microdisplay technology.As an essential and key laser component for laser applications,MEMS micromirror has penetrated into consumer electronics,medical care,military defense,communications and other application fields.At present,the power of laser light source of home theater level in the market is up to 100 watts.Most MEMS micromirrors developed at home and abroad are small in diameter,which makes it difficult to bear such a large power of laser.Therefore,the research on large-size MEMS micromirror in this paper has important market demand and scientific significance.In this paper,a large size electromagnetic MEMS micromirror which can meet the size requirements of optical system and the requirements of high resolution scanning image is proposed to solve the problem that the mirror size is too small and the resolution is too low.Theoretical analysis and torsional dynamics analysis were carried out on the micromirror;COMSOL finite element software was used to optimize and simulate the structure size of micromirror;The process design of MEMS micromirror is completed;The process design of MEMS micromirror was completed.Through analysis and calculation,the horizontal quick scanning angle of the 4mm electromagnetic drive MEMS micromirror designed in this paper is23.806°at the frequency of 17397 Hz,and the vertical slow scanning angle is 50.936°at the frequency of 441.77 Hz.The main research content is as follows:(1)The current status of display technology at home and abroad was studied.Four driving micromirror of electrostatic,electrothermal,piezoelectric and electromagnetism in laser scanning microdisplay technology are compared and analyzed,then the research target and main research work of electromagnetic MEMS micromirror was determined.(2)The driving principle of electromagnetic MEMS micromirror is studied.Based on the theory of electromagnetics,this paper analyzes the theory of electromagnetic MEMS micromirror and establishes the torsional dynamics model,which provides the theoretical basis for the size design of MEMS micromirror(3)The performance requirements of MEMS micromirror were studied.According to the influence factors of scanning angle and scanning frequency,the finite element simulation model was established in COMSOL software to optimize the size of the micromirror,torsion beam and permanent magnet.A series of important properties such as vibration modal,harmonic response characteristics and torsional beam stress are analyzed in this paper.(4)According to the designed MEMS micromirror structure,some important MEMS processes are compared and analyzed,and the process flow of the micromirror is preliminarily designed by means of film deposition,fabricating drive coil,etching and so on.