Hiap L. Ong

A full-color SXGA TN AMLCD for military head-mounted displays and viewer applications

We report progress in developing a 0.97-in diagonal AMLCD with a full color SXGA resolution. A 1280×1024×3 dot array was developed with integrated color pixel filters to create an SXGA color pixel array. These displays are fabricated on 8-inch SOI wafers and transferred to glass wafers to produce transmissive liquid crystal displays. Improvements have been made in this AMLCD to bring the fabrication process to manufacturing. Fabricating a 3.9 million pixel dot display on a 1-inch die required a new display design and fabrication in an 8-inch wafer line. The 8-inch process provided enhanced process capabilities and tighter design rules to achieve good performance and reasonable starting yields. An ASIC driver and ultra thin efficient backlight were developed to miniaturize the display module and to reduce total power to < 750mW for soldier mounted applications. Total package size is less than 0.5 in3. The ASIC will also drive Kopin SVGA and VGA color displays singly or in pairs for binocular applications. An end-to-end 8-inch wafer process was established at the wafer foundry and at Kopin. A 3-year manufacturing technology insertion program (Mantech) has begun to optimize the 8-inch line processes and the SXGA color display. Meeting yield and performance goals will reduce display cost and enable systems performance goals. Key results include vivid, high-resolution color, wide viewing angles and low power operation. Performance data and specifications will be presented.

26.1: Simple and Accurate Optical Reflection and Phase Compensation Methods for Reflective LCD Cell Gap

We developed two fast, simple, and accurate optical methods for reflective LCD cell-gap measurements. One method uses optical reflection, while the other uses optical phase compensation. They have higher accuracy, simpler setup and procedure, and lower cost than the present optical interference method. The typical measurement accuracy is about 0.05, 0.1, and 0.3um respectively, for phase compensation, optical reflection, and optical interference methods.

P-119: New Multi-Domain Vertical Alignment LCD with High Contrast Ratio and Symmetrical Wide Viewing Angle Performance and Simplest Fabrication Design and Process

We invented and successfully fabricated a new multi-domain vertical alignment (MVA) LCD with high contrast ratio and wide symmetrical viewing-angle performance. The LCD has a simple fabrication process without rubbing, with no surface protrusion, and no ITO slit geometry. The new MVA LCD makes use of the intrinsic fringe field in each pixel to control the LC alignment, and manifesting 2 domains under column inversion and row inversion, and 4 domains under pixel inversion operation. The viewing angle can be enlarged by the use of optical compensation films, and transmission can be enlarged by improved LC material, drive voltage, pixel design and circular polarizers.

8.3L: Late-News Paper: New Simple Cell Gap Measurement Method With Three Transmission Measurements

We developed a fast and simple optical measurement method to measure the LCD cell gap. The method uses the standard LCD measurement geometry with two polarizers, a monochromatic light source, and a detector, without other special components. We showed that only three measurements and a simple equation are needed for this cell gap measurement method.

Microdisplay opportunity : Small size, low power, big image, bright future

Microdisplays, which offers displays with small size, low power, big image, and a bright future, are particular useful for low power mobile personal communication and information display. Among all possible technologies, active matrix addressed liquid crystal displays using CMOS circuit fabricated in single-crystal silicon is presently the best approach for these microdisplays. A personal view on the microdisplay advantages and possible opportunities is summarized. A detailed description on the leading Kopin monochrome and color virtual displays is given.

P-144: Low Voltage, High Contrast Ratio, and Wide Viewing Angle TN LCD's for Microdisplay, Mobile Phone and PDA Mobile Video Applications

The modeled contrast ratio of a twisted nematic liquid crystal display (TN/LCD) was improved by over a factor of 2 to greater than 500:1 at applied voltages of 2 to 4 volts via the addition of a thin negative birefringence optical film with a retardation value up to 50nm and the optical axis parallel to the surface. Combining wide-viewing-angle compensation films with this thin negative birefringence optical film can lead to significantly improve viewing angle as well. This performance improvement is important for high performance microdisplay HMDs, mobile phone, PDA mobile video TVs, and 3D applications.

P-93: Process and Performance Improvements for a Simple Low-Cost Multi-Domain Vertical-Alignment LCD

Process and performance improvements have been made in Kopins simple, low-cost MVA liquid crystal display to bring the fabrication process closer to manufacturing. Key results include striation-free displays with spun-on polyimide alignment layers, elimination of boundary stick via pixel design, overall viewing angle improvement with an MVA-matched wide viewing polarizer, and transmission improvements with high delta n LC, cell gap, driving mode, LED and BEF backlight combination.

P-91: TFT Substrate Birefringence Induced Asymmetrical Viewing Angle and Compensation Methods

Thin-film transistor (TFT) processes for small pixel geometries can induce optical birefringence effects and change the viewing angle from symmetrical to asymmetrical. We experimentally identified the TFT substrate as the source of the birefringence and developed four methods to compensate the added optical birefringence effects to restore the symmetrical viewing angle. We also developed two special wide viewing angle polarizers with Fuji Film wide viewing angle film, and special compensation films to compensate the TFT substrates birefringence.

Improvement of LCD Viewing Angles by Negative Birefringence Compensation Films

Abstract The negative birefringence optical compensation films can be used to significantly improve the viewing angles of single-domain and multi-domain LCDs. We review the major applications of the applications of negative birefringence compensation to TN, STN, vertically aligned LCDs, and parallel aligned LCDs. Most recently, there are three TFT/LCD panels with improved large viewing cone being commercialized with the use of the negative birefringence optical compensation films. These panels include: (1). US TFT/LCD vendors compensated single domain TFT/TN panels; (2). Sharp compensated 2-domain Super-V TFT/TN panels; and (3). Fujitsu super-wide compensated 4-domain vertical aligned TFT/VA panels.

Developing the 1280 by 1024 AMLCD for the RAH-66 Comanche

A miniature 1280 by 1024 transmissive active matrix liquid crystal display (AMLCD) was developed for the helmet-mounted display in the RAH-66 Comanche helicopter. To meet the stringent environmental and optical performance requirements, improvements were made in the AMLCDs operating temperature range, viewing angle, pixel size, and transmission. These features were combined with technology previously developed to provide uniform gray scale, rapid optical response times, and ultra high-brightness imagery for the combination of high-resolution FLIR imagery and flight symbology viewable in daytime environments.