Study On Specific Viewing Angle Technology For Liquid Crystal Display

Currently,the max luminance of a LCD is along the normal direction.However,when used in the car,train and aircraft cockpit,there usually exists a certain angle between the max luminance of a LCD and viewers,resulting in energy waste and worse watch effects.The display needs to be tilted when used in these applications,resulting in the large volume and high costs.In order to effectively solve these problems,this paper designs an optical film,which can make the max luminance direction of a LCD directly to the viewers to save the space,improve the light efficiently,and reduce the cost.Firstly,the position of the angle deflection film is determined.Based on the luminous distribution of the existing backlight module and the non-imaging optics theory,the theoretical design for the microstructure surface of the angle deflection film is performed.The simulation analysis of the angle deflection film used in the side-lit and direct-lit backlight modules is then conducted.As the fact that the angle deflection is not enough and the gain appears outside the max intensity,the surface microstructure of the angle deflection film is optimized,based on the half-intensity incident angle.The simulation results show that the angle deflection satisfies the requirement.On the basis of the design,the corresponding angle deflection film are prepared by directly-writing lithography.The practical measurement results show that compared with the backlight module without such optical film,the max luminance of the side-lit backlight turns from 0° to 19.2°;the full width of half maximum changes from(-30.1°,29.9°)to(-30.0°,55.1°);the transmittance is 83.4%;the max luminance of the direct-lit backlight turns from 0 ° to 20.6 °;the full width of half maximum changes from(-18.0°,18.1°)to(-4.5°,42.1°);the transmittance is 81.0%.The optical film designed in this paper satisfies the requirement of special viewing angle.