Design And Fabrication Of Retinal Projection Laser Near-eyes Display Optical System

With the development of virtual and augmented reality technology,head-mounted displays(HMDs)have been widely used in the field of vehicle navigation,industrial production,medical treatment,education and entertainment.Retinal projection displays(RPDs)are an important developing direction in the field of HMDs,which can overcome the vergence-accommodation conflict(VAC)of traditional HMDs.Aiming at solving the problems of present RPD devices at home and abroad whose small field of view(FOV),large size and heavy weight which can't meet the requirements of portability,the principle and realization methods of RPD have been deeply studied in this thesis.Based on conventional optical elements and conicoid surfaces,two types of RPD systems with MEMS laser scanning projection have been developed.These two display systems have the advantages of large FOV,long depth of field(DOF),light weight and portability,which can be applied to various virtual and augmented reality applications.The main work of this thesis includes the following parts:1.By investigating a large number of related literatures on RPD,the principles of several theories,e.g.,the VAC,Maxwellian view and its modified modality,are introduced and analyzed.And then various methods to realize the RPD optical system are summarized.Based on the traditional RPD light path,we use MEMS laser scanning projection as the image source to set up two sets of monocular and binocular feasibility verification experimental light paths.Then the black speckle problem in the monocular system is analyzed,and the binocular stereo vision of RPD is verified.2.In this thesis,we solves the black speckle problem in the feasibility verification optical path,proposes the catadioptric system and designs a RPD optical system of interpupillary distance adjustable and without image distortion.Then according to the imaging quality analysis,the tolerance analysis and the mechanical structure design of the RPD system,the prototype of the RPD system has been developed,with a 40° FOV,a 10 mm exit pupil distance(EPD)and a small portable structure,whose long DOF display effect is verified by experiments.3.In order to further expand the FOV of RPD system,combining with the optical properties of conicoid,three kinds of side projection style RPD system based on ellipsoidal and hyperboloid are constructed.To solve the problem of non-adjustable interpupillary distance of the side projection style,an idea of vertical optical system is put forward,based on which,the parameters of the reflector are set.The optical lens and its mechanical structure are designed and processed.The prototype of RPD system based on conicoid is developed,with an 80° FOV,a 30mm EPD,a small volume and a compact structure.