Ji Ho Hur

54.4: 4.1 inch Top-Emission AMOLED on Flexible Metal Foil

We have developed a 4.1 inch AMOLED display with top emission structure on stainless steel foil. The p-channel TFTs on metal foil exhibited the field-effect mobility of 75.1 cm2/Vs, threshold voltage of −3.9V, and subthreshold swing of 0.9V/dec. Active-matrix back planes were fabricated with the poly-Si TFT with a conventional pixel circuit consisting of 2 TFTs and 1 cap. The scan driver circuits with PMOS were integrated on the metal foil.

15.2: 2.0 inch a‐Si:H TFT‐LCD with Low Noise Integrated Gate Driver

We developed a 2.0 inch, QCIF (160×128×RGB), a-Si:H TFT-LCD with a low noise gate driver integrated on glass substrate. By simulation and measurement, the proposed gate driver was found to be noise-free compared to conventional one. A new gate driver can make it possible to perform operation regardless of the voltage coupling from other voltage sources.

49.3: A 200‐dpi Transparent a‐Si TFT Active‐Matrix Phosphorescent OLED Display

We have fabricated a 120×160 high-resolution (200dpi) a-Si TFT active-matrix transparent phosphorescent OLED (PHOLED™) display with novel pixel architecture to maximize transparency and aperture ratio and also ensure comparable light emission from both sides of the display. The a-Si backplane was selected as the technology that would most easily enable the pathway toward achieving high-resolution flexible transparent AMOLEDs (T-AMOLEDs) on polymeric substrates. A-Si TFTs are preferred for fabrication on polymeric substrates since lower process temperatures can be used in comparison to poly-Si TFT processes. As a TOLED generally emits less light from a transparent cathode than anode, a standard 2T pixel was designed with both an opaque, reflective anode region on top of the TFTs as well as a conventional transparent ITO anode to equal the emission from both contacts. This design achieves a total pixel aperture ratio of 64% with a display transparency of 23% in the off-state.

43.3: Power Efficient AMOLED Display with Novel Four Sub-Pixel Architecture and Driving Scheme

We present a novel all-phosphorescent AMOLED pixel architecture with a red, green, light blue and deep blue sub-pixel design. The highly efficient light blue reduces power consumption by 33% compared to an equivalent conventional RGB display using a fluorescent blue sub-pixel. Furthermore, by using a light and deep blue sub-pixel layout, the lifetime of the display will be significantly increased due to the reduced on-time required for the deep blue sub-pixel. Here we demonstrate this new design in a 2.5-inch AMOLED panel.

25.3: Auto‐Stereoscopic TFT‐LCD with LC Parallax Barrier on Wire Grid Polarizer

We have developed a 5.5 inch auto-stereoscopic TFT-LCD (640 × 480 × RGB) display with LC (liquid crystal) parallax barrier having the pitch of 58 μm on the back of wire grid polarizer substrate. The auto-stereoscopic display of the proposed structure can be 2D/3D convertible LCD, indicating that it can provide us with 3D display as well as conventional 2D display. The auto-stereoscopic 3D display with wire-grid polarizer has the advantages of short viewing depth and thinness.

Coplanar ZnO Thin-Film Transistor Using Boron Ion Doped Source/Drain Contacts

We studied a coplanar zinc oxide (ZnO) thin-film transistor (TFT) using boron ion doped source/drain contacts. The ZnO was sputtered using an Ar and O 2 mixture at a substrate temperature of 150°C. The boron ion doped (~10 15 /cm 2 ) ZnO layer, having a sheet resistance of ~0.9 kΩ/?, was used as the source/drain contacts of the TFT. The coplanar ZnO TFT exhibited a field-effect mobility of 54.4 cm 2 /V s, a threshold voltage of 4.48 V, a gate voltage swing of 0.29 V/dec, and an on/off ratio of ~10 7 .

32.1: Stereoscopic TFT-LCD with Wire Grid Polarizer and Retarder

We developed a 5.5 inch, VGA (640×480×RGB), stereoscopic 3D display using a wire grid polarizer on patterned retarder. The proposed stereoscopic display uses the existing TFT array panel and a color filter on a wire grid polarizer on patterned retarder. Since a wire grid polarizer is placed adjacent to the LC layer, there is no limitation on viewing angle and viewing distance. Therefore, it is possible for many people to watch stereoscopic display simultaneously.

28.4: High-Resolution Stereoscopic TFT-LCD with Wire Grid Polarizer

We developed a 5.5 inch, VGA (640×480×RGB), stereoscopic 3D display using a precisely patterned wire grid polarizer (WGP) with rows of alternating polarization angle. Such a wire grid polarizer is invisible without the polarizer and thus a 2D/3D convertible display can be formed. The proposed structure is free of any limitations on both viewing angle and viewing distance inherent in the conventional stereoscopic displays, whereby enabling several persons to view stereoscopic image simultaneously. Because the proposed structure does not use conventional polarization film of TFT-LCD panel, it can be manufactured with low-cost.

A 2-in. a-Si:H TFT-LCD with embedded backlight control TFT sensors with various channel widths

— A 2.0-in. a-Si:H TFT-LCD with embedded TFT sensors for the control of the backlight intensity according to the ambient light intensity has been developed. Two types of a-Si:H TFT sensors with various channel widths were embedded into a TFT backplane with bottom- and top-gate structures for measuring the ambient light and backlight illumination, respectively. The output signal, measured by a readout IC, increased with backlight intensity until 20,000 lux.

8.4: A Wire Grid Stereoscopic Display

We developed a 2.0 inch, QCIF (160×128×RGB) resolution, stereoscopic 3D display using wire-grid polarizer (WGP) patterned with the rows of alternating polarization angle on it. The stereoscopic display of the proposed structure can be 2D/3D convertible LCD, indicating that it can provide us with 3D display as well as conventional 2D display. The proposed structure is free of any limitations on both viewing angle and viewing distance, which is inherent in the conventional stereoscopic displays. This enables multiple persons to view stereoscopic image simultaneously.