Research On Crosstalk Of Small Interval LED Based Auto Stereoscopic Display System

Auto stereoscopic display technology can improve people's viewing comfort,and allow people getting rid of the shackles of visual aids.LED display screen inherits advantages in display field,such as long life time,extensibility and high brightness.It is an important direction to build free stereoscopic display system based on LED display screen.Raster based LED auto stereo display system is mainly composed of LED display screen and raster part.The LED display screen is used to for image display,and the raster completes the parallax image separation.Moire fringes and the crosstalk between parallax images are two most important factor to affect stereoscopic effect.In this dissertation,we discussed the origin and suppression of cross talk in raster based LED auto stereoscopic display system.Main work includes as following:(1)The influence of horizontal and vertical arrangement of sub-pixel on crosstalk.Through jointly used of Trace Pro simulation and experimental measurement,it is found that for1.25 mm LED screen,the crosstalk of the system is equivalent as the sub-pixel is arranged horizontally and vertically,respectively.The crosstalk of the model with sub-pixel area of0.1*0.1 mm is about 7% lower than that of the model with sub-pixel area of 0.3*0.3 mm,and the crosstalk has exceeded 40% when the sub-pixel area exceeds 0.3*0.3 mm,which is not conducive to the realization of auto stereoscopic display.Thus the sub-pixel arrangement direction can be selected according to the actual needs,as LED screen is used in auto stereoscopic display.The influence of sub-pixel duty ratio on crosstalk.Through Trace Pro simulation,the crosstalks of LED free stereo display system with different sub-pixel duty cycles were analyzed.The results show that the crosstalk rate increases with the increase of sub-pixel area and duty cycle.The corresponding relationship between sub-pixel duty cycle and crosstalk is obtained,which provides a reference for the selection of LED screen in free stereoscopic display system.The influence of sub-pixel position offset on system crosstalk.In the practice,the sub-pixels in LED are not strictly disributed with the equal interval,but shows a certain offset relative to the equal interval arrangement.Through Trace Pro simulation,the dependeces of crosstalk on sub-pixel duty cycle and position offset were obtained.The results show that two or three adjacent sub-pixels from the same lamp will be assigned to the same paraleex image,as sub-pixels undergoes some position offest.This can leads reduction of the system display crosstalk.Oue results shows that the position offset of sub-pixel can provides a disadvantage for the realization of free stereo display system.(2)The influence of light refraction in glass substrate on the crosstalk of the system.Through both experimental measurement and Trace Pro simulation,the crosstalks of sysem in different viewing angles are discussed.The results show that when the glass substrate is placed between the grating and the LED screen,the optimal viewing position of the system under different viewing angles appears as a curved surface.With the increase of viewing angle,the system crosstalk will increase accordingly.When the viewing angle changes from 0°increase to 20°,the crosstalk increases by 6 percentage points.(3)The feasibility of the lenticular lense based LED auto stereoscopic display system.The virtual sub-pixel is introduced into the design of lenticular lense parameters in order to decrease the sub-pixels distance used in parameters design.By using Trace Pro simulation,the seperation performances of parallax images under parallex barriers and lenticular lense were compared and analyzed when they works under the same number of parallex images.The results show that the lenticular lenses have better performance in parallex imgages seperation for light refrax mechnism.The research works in this dissertation prove that quality of auto stereoscopic display based on LED screen can be optimized by property adjust the sub-pixel arrangement direction,duty cycle,offset and viewing angles.The virtual sub-pixel is introduced to simulate the lenticular lense auto stereoscopic display system.With respect to parallex barriers,the lenticular lesese can suppress the system crosstalk,improve the brightness of display system.