Experimental Study On Depth Scan For Volumetric Display With Shaftless Drive

Since the world of human being is three-dimensional,the 3D display technology has become a pioneer's dream since the first electronic display can display two-dimensional images.With the rapid development of technology,the century dream is coming true at an unprecedented rate.Up to now,the three dimensional display technology covers three major categories:stereoscopic display,holographic display and volumetric display.This paper briefly introduces the principles and development of these three kinds of display technology.The volumetric display technology is reviewed in detail.It is pointed out that the bitmap scanning volumetric display based on parallel section technology is the focus of research because of its high imaging quality.At the same time,it listed the use of shaftless drive technology in several areas and two main conditions,speed variations and load relatively stable,for application of shaftless drive technology.The scanning system for deep volumetric display also happens to have these two characteristics,therefore the shaftless drive is feasible to be used in depth scanning system.Aiming at solving the problems of large vibration and noise and poor reliability of mechanical synchronous driving device used for volumetric display,a new shaftless drive scheme for volumetric display is proposed.The scheme uses the step motor with double-output shaft.The rotor is fixedly connected with a planetary frame,which relies on electromagnetic synchronization technology to ensure the imaging screen frame angle relative to the planet and the planet frame relative to the frame angle have the same size and opposite direction,so as to realize circular translational depth scanning imaging screen;Since the synchronization between different shafts adopts the electromagnetic signal of shaft,this scheme will try to solve the problem of vibration and noise problems due to mechanical transmission at high speed and mechanical wear caused by long-term work.Theoretically,the new scheme requires the use of servo motor to achieve closed-loop control,while there is no available servo motor in the market to meet the requirements but the stepper motor to meet the demands.Therefore,the experimental equipment bases on the stepper motor to verify the feasibility.Because the stepper motor is adopted in the experimental device and the open loop control is adopted in the electromagnetic synchronization,the synchronization between different stepper motors is the key and difficult point.In this paper,the load characteristics of the deep scanning system are studied,and different acceleration curves are compared with each other.A smooth stepper motor acceleration and deceleration curve is designed,and the feasibility and superiority of the new scheme are verified by experiments.At the end of this paper,some suggestions for optimizing the design,processing and assembly of the experimental device are put forward.