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Active Matrix Liquid-Crystal Displays for TV and Office Systems

Objective

For a long time Europe has held a distinguished record in developing and fabricating liquid crystal materials. Today, the three companies Merck (D), BDH (UK) and Hoffman La Roche (CH) almost control the entire world market for these materials. Nevertheless, the European position on LC devices, components and sub-assemblies for panels is less favourable, and Japanese suppliers dominate the global market, with large sales in Europe.

There are, however, a number of European companies with the technical capabilities to produce LCDs and to compete worldwide, provided that production investments are made on an appropriate scale for a well-defined technology.

Investigation of the different technological requirements for the production of a large complex flat-panel display has been completed.

The approach, which is now widely recognised as the most promising, is to deposit a matrix of switching transistors on an inner wall of the LCD (AMLCD). Three of the partners have demonstrated their technical know-how in the field of active matrix panels by the realisation, at the laboratory level, of displays with viewing areas of approximately 10 x 10 cm{2} and resolution up to 256 x 256 pixels (see project 833).

Although applications for such displays are expected in small portable equipment and video projectors, it seems necessary to develop larger (A4) high-resolution panels to meet the key requirements of office terminals. The main goal of the project is therefore to validate technologies for the production of active matrix LCDs up to A4 in size.
There are a number of European companies with the technical capabilities to produce liquid crystal displays (LCD) and to compete worldwide, provided that production investments are made on an appropriate scale for a well defined technology. Such a display, compact and operating at low voltage, must be able to show colour and grey scale with high resolution and should be less bulky than current cathode ray tube (CRT) devices in orderto fulfil office systems requirements in the near future.
The main goal of the project is therefore to validate technologies for the production of active matrix LCD up to A4 in size. The work involves the preparation of direct view flat panel displays using amorphous silicon wilth external integrated circuit (IC) drivers in the short term, or using polycrystalline silicon with integrated drivers as an alternative in the longer term. During the first 3 years of the project the realization of an A4 amorphous silicon matrix will be carried out, and, in parallel, a polycrystalline silicon process with integrated drivers and A4 glass compatibility, including A4 specific equipment, will be developed (6 inch diagonal demonstrator).
A complete new facility dedicated to the realization of 14 inch x 14 inch substrate displays has been built near Grenoble, and is already experiencing problems arising form amorphous silicon display production in a pilot line. A5 8-colour displays have been demonstrated as a first step towards the final goal. The processing of the panels is on course. The consortium recently demonstrated a 2.8 inch diagonal active matrix LCD display with fully integrated polysilicon row and column drivers. The device contains a 200 x 200 pixel array, and can be driven through a 28-pin connector.
The work involved the preparation of direct-view flat-panel displays using amorphous silicon with external IC drivers in the short term, or using polycrystalline silicon with integrated drivers as an alternative in the longer term.

Coordinator

Thomson Liquid Crystal Display
Address
Zone Industrielle Centr'alp
38430 Moirans
France

Participants (7)

AEG Olympia AG
Germany
Address
Soeflinger Straße 100
89077 Ulm
ARISTOTELES UNIVERSITY OF THESSALONIKI
Greece
Address

54006 Thessalonik
CETIA
France
Address
150 Rue Marcelin Berthelot
83078 Toulon
DEUTSCHE THOMSON-BRANDT GMBH
Germany
Address
Hermann-schwer-straße 1
78048 Villingen-schwenningen
Interuniversitair Mikroelektronica Centrum
Belgium
Address
Kapeldreef 75
3030 Heverlee
Rytrak Ltd
United Kingdom
Address
Wavertree Technology Park
L7 9PF Liverpool
THOMSON VIDEO EUROPE
Germany
Address
Am Krebersgraben 15
78078 Villingen-schwenningen