Session Index

Active-matrix organic light-emitting diode (AMOLED) and micro-light-emitting diode (micro-LED) displays are expected to be the next -generation of display technology. In this talk, the characteristics of thin-film-transistors (TFTs), and their operation principles, pixel circuits, and driving schemes are systematically investigated for promising high-resolution, high-brightness, and high-image-quality display applications. For AMOLED displays, the electrical issues of devices, the classification of driving methods, and the comparison of various pixel circuits are introduced. To extend the period of sensing of threshold voltage (VTH) variations of TFTs, a high-resolution AMOLED pixel circuit that uses overlapping compensation times is presented. The increased sensing period of 33.3 μs results in a higher contrast ratio and more precise VTH compensation than those with sensing periods of 4.3 and 2.2 μs. Also, a pixel circuit with a leakage-prevention method (LPM) is proposed to balance the off currents at the gate node of the driving TFTs, which eliminates the drop in the driving voltage, for AMOLED smartwatch displays at a low frame rate of 15 Hz. For micro-LED displays, the recent development trends, power consumption issues, and the pulse-width modulation (PWM) driving method of micro-LEDs are analyzed. A mini-LED driving circuit that adopts the PWM driving method is proposed for use in a liquid-crystal display (LCD) backlight. Since this circuit uses the PWM method, the mini-LED can be operated at the a high luminance-efficacy point, reducing the power consumption of the mini-LED driving circuit by more than 21% compared to that of a circuit driven by pulse amplitude modulation (PAM). Finally, the pros and cons of the driving schemes for AMOLED and micro-LED displays and their future perspectives are discussed

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Unique Characteristics of Cholesteric Liquid Crystal Display
* Vivid picture - Infinite Color
* Self-powered by solar cell - Infinite Power
* Various application - Infinite Usage Scenario

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This study uses a twisted nematic mode polymer-stabilized liquid crystal (TN mode PSLC) and combined with a crossed polarizer to make a transparent waveguide display. PSLC scatters the edge-lit light with a great polarization selectivity when applied voltage so the majority of the scattered light can pass the analyzer with small loss. On the other hand, most of the background light was absorbed by the analyzer in the ON state. With this structure, we can display waveguide light by scattering while keeping off the background light to achieve better image quality.


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In this work, we propose a method based on angle-dependence Bragg reflection to simulate the diffraction pattern of a three-dimensional liquid crystalline photonic crystal (3D LCPC). The simulated diffraction pattern goes well fitting with the experiment one so that we can extract the lattice parameters of a 3D LCPC. In addition, we can construct a wavelength-scanned 3D diffraction pattern of a 3D LCPC with different lattice symmetries to analyze their dispersion relation.

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Self-assembled periodic micro/nanostructure responses triggered by external excitation often occur in anisotropic self-assembled supramolecular systems such as liquid crystal systems. However, the orderliness of these structures is barely controlled. This study sets a precedent that large-area ordering of 2D supramolecular chiral microstructures based on electro-induced Helfrich deformation can be achieved by utilizing the guidance of pre-established 1D periodic microgrooves on substrate. The influences of depth and spacing of microgrooves on the arrangement of the 2D microgrid structure were also investigated. It is expected that this method could be applied to general self-assembled periodic microstructures regardless of external stimuli or materials.

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In this study, we use two-photon technology to fabricate two-dimensional microchannel structures which can control the liquid crystal (LC) alignment of liquid crystal networks (LCN). These micro-channels can achieve horizontal alignment of LC without electrical control. Moreover, a programmable soft actuator with a high-resolution complex pattern of LC alignment could be achieved. Such a planar liquid crystal alignment method provides great applications in biomimetic small-scale actuators and medical microsystems.

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