基于公共场合隐私保护的需求, 宽窄视角可切换的液晶显示技术有着迫切的市场需求。现有宽窄视角切换技术不但增加了显示装置的厚度与成本, 而且降低了原本宽视角模式下的显示效果。本文研究了一种基于负性液晶FFS模式的宽窄视角切换技术, 它通过在彩色滤光片一侧形成高预倾角配向(40°~60°), 在同侧第三电极施加弱电场时, 液晶分子离轴方向具有较大相位延迟, 形成大视角观看时的暗态漏光与对比度下降, 实现窄视角显示模式。而同侧第三电极施加强垂直电场时, 大的预倾角液晶分子因负介电各项异性使得倾角降低, 可减少暗态漏光和提升对比度, 实现宽视角显示模式。验证结果表明: 宽视角模式时, 其上下左右视角均可达到85°以上; 而窄视角模式时, 左右视角仅为40°, 且具有较好的对称性。本技术结构简单, 驱动灵活, 在防窥显示领域具有很好的应用前景。

Due to the privacy requirements of public places, viewing angle switchable liquid crystal display (LCD) technology has been an urgent market demand. The current viewing angle switchable technologies not only increase the thickness and cost of the display device, but also reduce the original wide viewing angle mode display. In this paper, a viewing angle controllable FFS mode with negative LC is proposed. By applying a high pre-tilt angle (40° ~ 60°) on the side of the color filter, the third electrode is ipsilateral as color filter. When a weak electric field is applied to the third electrode, LC molecules from the axis direction have a large phase delay. The formation of large viewing angle has the dark state of light leakage and contrast reduction, resulting in the narrow viewing angle display mode. When the strong electric field is applied to the third electrode, the LC molecules with large inclination angle decrease the inclination angle due to the negative dielectric anisotropy, which can reduce the dark light leakage and enhance the contrast, resulting in the wide viewing angle mode. The experiment results show that the viewing angle of all the direction can reach more than 85° in the wide viewing angle mode, and the left and right viewing angles are only 40° in narrow viewing angle mode with good symmetry. Due to the simple structure and flexible driving, the technology shows great potential application in anti-peep display.