Chung Yung Lee

Tunable lens by spatially varying liquid crystal pretilt angles

We report a method of obtaining controllable spatially varying liquid crystal pretilt angles using a stacked alignment layer. The stacked alignment layer consists of nano-domains of horizontal and vertical alignment materials. The pretilt angle is controlled by varying the domain ratio of the two layers. By using photoalignment material as the top layer, the pretilt angle can be controlled by varying the UV light dosage. A spatially variable UV light beam can be used to control the pretilt angle spatially. An electrically tunable-focus liquid crystal lens is obtained using this method.

32.3: Simple Single‐Layer Multi‐Touch Projected Capacitive Touch Panel

A simple projected capacitive touch panel is developed. This touch panel is capable of detecting multi-point touch events. The device consists of a single piece of patterned transparent ITO glass and a sensing circuit. The applied driving signal is projected onto the sensing node in the form of an electric field. A charge sensing circuit is used to monitor the mutual capacitance between the driving and sensing nodes. This approach provides a simple and low cost alternative to current capacitive multi-touch panel design.

Liquid crystal dynamic flow control by bidirectional alignment surface

We investigate the behavior of liquid crystal dynamic flow in a cell with a bidirectional alignment (BDA) surface. Numerical simulations show that with a BDA surface having a pitch comparable to the cell gap d, the liquid crystal dynamic flow direction can be controlled by the driving voltage. Such an effect can be applied to bistable twisted nematic displays without the need for anchoring breaking.

P-124: Study of stacked alignment layers on a single substrate with spatial liquid crystal pretilt angles and its applications

In this paper, we report recent developments in stacked alignment to generate spatially varying liquid crystal pretilt angles. This is a nanostructure alignment surface that can be produces any pretilt angle on a single substrate. The pretilt angles profile can be controlled. An electrically tunable liquid crystal lens using such nanostructure alignment surface is demonstrated

P‐133: Variable Liquid Crystal Pretilt and Azimuth Angle Using Stacked Alignment Layers

A new alignment layer is developed. This alignment layer is capable of generating arbitrary pretilt and azimuth angles for the liquid crystal. It is based on stacking both photo-aligned polymer and rubbed polyimide together. The alignment produced is robust. Moreover, the processing window is also maximized.

67.2: Permanent Bistable Twisted Nematic Displays Using Bi-Directional Alignment Surface

A new bi-directional alignment surface is developed. Such alignment surface can be used to control the backflow direction of the liquid crystal. Base on this new alignment layer, a bistable twisted nematic LCD which switches between U and T states without surface anchoring energy breaking has been fabricated successfully.

Stereoscopic three-dimensional display with a fast-response liquid crystal polarization rotator

A stereoscopic three-dimensional (3D) system using a polarization rotator is proposed. The polarization rotator converts the polarizations of images from different eyes in temporal multiplexing. A novel fast nematic liquid crystal mode is also proposed. The new liquid crystal mode has a fast response time and a high contrast, and is thus a good candidate as a polarization rotator. The proposed 3D system uses only passive polarized glasses, which are more convenient, lightweight, and low-cost than what? In addition, the polarization rotator can be applied to current two-dimensional displays and can become 3D-capable displays.

41.4: Discontinuous alignment thin-film formation by self-organized dewetting

A new discontinuous alignment layer is developed. The formation of such discontinuous structure is created by self-organized dewetting. Different dewetting mechanisms have been investigated. Such a discontinuous alignment layer can be fabricated on top of a continuous alignment layer. This heterogeneous surface for liquid crystal alignment can be used to produce arbitrary pretilt angles for the liquid crystal cell. Experiments using photo-aligned polymer have been done to verify the dewetting theory. The alignment layers thus produced are proved to be robust. Moreover, the dewetting step is a fully controllable process and is compatible with existing manufacturing techniques.