Abstracts of Magazine FUJITSU 1998-5 (VOL.49, NO.3)

Special Issue : Displays

• Super High Quality MVA-TFT Liquid Crystal Displays

Liquid crystal displays (LCDs) are becoming a popular alternative to CRT monitors. Fujitsu has developed super high quality Multi-domain Vertical Alignment (MVA)-TFT LCDs for high-end applications based on a completely new vertical alignment concept. The MVA technology eliminates the need for a rubbing process in manufacturing. This makes MVA-TFTs simple and stable. Also, an extremely wide viewing-angle,high contrast ratio,and fast response time have been achieved.
This article describes the technology and performance of the newly developed super high quality MVA-TFT LCDs.

• Low Power Consumption, Thin-module, Lightweight TFT-LCDs for Notebook PCs

Thin-Film Transistor Liquid Crystal Displays are playing a critical role in the evolution of today's notebook PCs. Today's large screen,thin-module,lightweight,low power consumption TFT-LCDs have made it possible to realize the functionality of a desk-top PC's large,high-resolution screen in a lightweight notebook PC that has an extended battery life.
Fujitsu's contributions to notebook PC evolution include the development and manufacture of advanced TFT-LCDs. Fujitsu's latest development is a new TFT-LCD that combines a large-screen (12.1-inch),high-resolution (800 × 600) display with a full 260K color palette. This TFT-LCD consumes only 3.55 W, weighs a mere 420 grams, and is only 6.2 mm thick.
Fujitsu believes that this display will play an important role in the evolution of tomorrow's advanced notebook PCs.

• High-Brightness SVGA LCD Projector

Multimedia presentation using LCD projectors has become very popular. Fujitsu,one of the pioneers of LCD projectors for presentations,has supplied VGA LCD projectors since the beginning of the projector market and now has kept their brightness highest among the transportable projectors.
Recently, we have developed new technologies for higher brightness, for example, high-intensity light source,wide-aperture and high-transmittance LCD panels,and have used them to produce the world's first SVGA LCD projector with a brightness of over 1,000 lumens.
This paper briefly explains Fujitsu's products policy and gives a brief history of how Fujitsu's products have evolved. Then, it describes the brightness enhancement technologies and presents the specifications of the new PJ-S1200, which boasts a brightness of 1,200 lumens.

• Formation of High Quality Poly-silicon for TFT-LCDs

To achieve a low-cost, high-aperture ratio, and high-resolution poly-silicon (p-Si) TFT-LCD panel, formation of high-mobility p-Si on a glass substrate at low temperature is necessary.
To meet this need,a new p-Si crystallization method called the double layer method has been developed. This method features a two-step preparation,each step consisting of amorphous silicon deposition followed by excimer laser annealing. The high quality of p-Si obtained with this method is attributed to the presence of surviving crystalline Si seeds when the second laser irradiation is performed.
The n-channel TFT is fabricated by temperature processing at 450℃,and a field effect mobility of 300 cm²/Vs is obtained.

• Development Trend of Ferroelectric Liquid Crystal Diaplays

The production volume of twisted nematic LCDs,which made portable information processing equipment possible,is surging. However,the characteristics of twisted nematic LCDs are poor compared with the characteristics of CRTs.
In response, R&D efforts are now being directed towards developing an LCD technology that can match and even excel the display quality of CRTs. This paper describes one of the most promising candidate technologies; namely,ferroelectric LCD panels.

• Characterization of AC-PDPs using Wall Voltage Transfer Curves

Color plasma display panels (PDPs) are key devices for multimedia networking. They are expected to improve in terms of picture quality and power consumption. To achieve these improvements, it is necessary to better understand the discharge phenomena of PDPs and develop better device structures and driving schemes. However,it is not clear how the device structure and driving waveforms should be changed to improve PDP characteristics.
This paper describes the device structure and driving scheme of our color PDPs. We begin by explaining the discharge sequence of AC-PDPs and their device properties. Then, we introduce the characteristic curve (wall voltage transfer curve) that shows the dependence of wall voltage change during discharge on the voltage across the discharge gap at the beginning of discharge. This characteristic curve can also be used for designing the driving waveform of PDPs. Finally, we present the curves measured from different device structures and discuss the relationship between the discharge phenomena and the structure.

• PDP Technology for High Picture Quality

Because of their lightness and thinness, Plasma display panels (PDPs) are increasingly expected to penetrate the consumer market in areas such as wall-hanging TVs.
In recent years,although the display performance of PDPs has been brought closer to that of the CRTs for home use, certain problems, for example, motion picture disturbance, still remain because of the PDP's driving method.
This paper describes a techniques for improving motion picture quality and describes the LSIs employed in this technique.

• Cell Structure and Driving Method of 25-inch Diagonal, High-resolution Color AC Plasma Display

In September 1997, Fujitsu released the world's first 64 cm (25-inch)diagonal,high-resolution color Plasma Display Panel (PDP) with 1,280 × 1,024 pixels (SXGA). The panel has a white peak luminance of 150 cd/m² and 256 gray levels. The key technologies for realizing the high-resolution color PDP are a new cell structure and a new high-speed driving method. The new cell structure was adapted to achieve high-speed,low-voltage driving. The new driving method can drive twice as fast as the conventional driving method.
This paper describes the cell structure and driving method of this new display.

• 25-inch SXGA High-resolution Color PDP

Fujitsu has now manufactured trial versions of the world's first high-resolution, 64 cm (25-inch), color plasma display which can be used as an SXGA monitor for a workstation or personal computer. These monitors have 1,280 × 1,024 picture elements,16,700,000 colors,a brightness of 150 cd/m², weigh 20 kg, and are only 110 mm thick. We plan to market these monitors in 1998.
We have developed the technology for realizing a fine cell pitch of 130μm based on a three-electrode surface discharge structure that is patented by Fujitsu and is established as an industry standard.
We have also developed a new driving technology which enables us to double the number of display electrodes used in our conventional PDP and thereby enables scanning of 1,024 lines at high speed.
This paper introduces the new 25-inch color plasma display and the new driving method it uses.

• Perfomance Feature of High Contrast Ratio, 42-inch Diagonal, Color Plasma Display Panel

Fujitsu has developed the world's highest contrast ratio 42-inch (106 cm) diagonal, plasma display panel. It has a 400:1 dark room contrast ratio and a 30:1 daylight contrast ratio. To obtain such high ratios, Fujitsu developed two key technologies.
One of these technologies is a black belt structure that improves the daylight contrast ratio by decreasing the surface reflection. This means that the non-discharge gap, which does not contribute to the display discharge, is dark.
The second technology is a new driving method that reduces the background luminance by reducing the level of the priming charge and makes the color more reliable by reducing the background luminance.

• Field Emission Display

Vacuum microelectronics based on the field emitter array (FEA) is currently being extensively studied for applications in field emission displays (FEDs). The advantages of the FED are its high resolution, high brightness, low power consumption, and high-speed response. However, before FEDs can gain a market advantage over other types of flat panel displays,their brightness and life expectancy must be increased.
This paper presents a new panel structure and fabrication method that improve the characteristics of FEDs.

• Development of ATOMICA, an Encyclopedia for Public Acceptance of Atomic Energy Accessible on the Internet

Encyclopedia ATOMICA is an easy-to-use database of figures and tables designed to promote public acceptance of atomic energy. ATOMICA contains information on topics such as energy sources, global environmental problems and their counter measures, how nuclear power stations work, recycling of nuclear fuels, processing of radioactive waste, decommissioning of nuclear reactors, the uses of radiation, radiation and protection, overseas information, and non-proliferation of nuclear weapons.
ATOMICA for telecommunication was released for use by the general public in March 1995. A version of ATOMICA has been available on the Internet since October 1996. The third version, which was released in February 1998, features improvements in areas such as the appropriateness of keyword searches, window views,and index searching of the technical terms dictionary.
This paper describes the main features of ATOMICA and how to use the third Internet version of ATOMICA.

• Information System Using Satellite Network

The prices of personal computers continue to fall and their performance continues to increase, so much so that personal computers capable of processing large amount of data are now within easy reach of many private users. These improvements have also encouraged many companies to build client/server systems in their offices throughout Japan. However,there is no network which can provide quick and inexpensive communications.
Fujitsu announced new types of satellite information services in April last year. These services resolved several major problems and won Fujitsu several important business agreements.
This paper explains the configuration, operation, and efficiency of typical systems that use Fujitsu's satellite information services.

• Secure PC Card

Secure PC card is an encryption/decryption system for data files that must be protected from unauthorized persons.
The encryption and decryption are performed automatically and do not require any modifications to be made to the application software, for example, a word processor, that is performing operations with the file.
The encryption key is built into the PC card and therefore cannot be read out from the card.
The card contains a DES encipher/decipher chip which enables it to encrypt and decrypt at 10 times the highest rate that can be achieved with software encoding.