四向宽窄视角可切换的液晶显示技术

Four-ways viewing angle switchable liquid crystal display technology

为了提升人们对于电子设备的个人信息隐私保护,在许多公共场合都需要显示装置具备宽视角与窄视角相互切换的功能。本文研究了一种可实现四向防窥的宽窄视角可切换的液晶显示技术,通过特定的像素电极结构设计将一个子像素分割为两部分,采用单一液晶配向方式来实现宽视角与四向窄视角模式的自由切换。本文所述的液晶显示装置其上基板一侧设有视角控制电极,下基板一侧设有像素电极和公共电极。当视角控制电极给公共电极信号时,下基板侧的像素电极和公共电极所形成的边缘电场使液晶分子向不同方向水平旋转,实现宽视角显示模式。当视角控制电极施加偏置的交流电压时,液晶分子在水平电场和垂直电场共同作用下进行旋转并形成较大的倾角,使液晶分子在离轴方向具有较大的相位延迟,形成大视角的暗态漏光,从而实现四向窄视角显示模式。实验结果表明宽视角显示模式时,其上下左右视角均可达到60°以上,且画面清晰可见。窄视角显示模式时,其视角在上下大于60°、左右大于45°时,具有良好的防窥效果。本技术架构简单,无需额外增加任何器件,通过单一液晶显示面板,单一背光源下即可实现四向视角进行宽窄切换的目的。

In order to improve the privacy protection of personal information for electronic devices,the display devices are required to have the function of switching between wide and narrow view angle,especially in many public places.In this paper,a four-ways view angle controllable liquid crystal display technique is investigated with a specially designed pixel by dividing a sub-pixel into two domains,which realizes the wide and four-ways narrow view angle switchable with a single liquid crystal alignment direction.The display device described in this paper includes a view angle controllable electrode in the top substrate,the pixel and common electrodes are placed in the bottom substrate.When the view angle controllable electrode is set as common voltage,the fringe field is formed between pixel and common electrodes make the liquid crystal rotate horizontally toward different directions,so the wide view angle mode is realized.When the alternating voltage is applied to the view angle controllable electrode,the liquid crystal molecules rotate and have a large tilted angle under the action of horizontal and vertical electric fields,the liquid crystal molecules have a large phase delay at off-axis direction,and induce the light leakage in the dark state,so the four-ways narrow view angle effect is achieved.The experiment results show that the wide view angle can reach more than 60°in vertical and horizontal direction and the pictures are clearly visible.In the narrow view angle mode,it is perfect blocked in the view angle at 60°of polar angle in vertical direction and 45°in horizontal direction.The technical structure is simple,without any extra components,and the four-ways view angle switchable structure can be realized with one liquid crystal cell and one backlight.