Skip to main content

Colour Research for Outdoor Matrix liquid crystal display Applied To Electronic Advertising and Message boards

Objective

The basic objective is the introduction of the LCD technology into the area of large (giant) outdoor electronic multicolour matrix information boards to decrease by 1:5 both cost and power consumption compared to existing emissive displays. This will be achieved by using TN positive mode LCD with a single cell per pixel in conjunction with a multicolour light converter based on silkscreen inks with stable daylight fluorescent dyes. This project aims to create a new medium for a public display network, which can be interconnected to telecom network. The first applications will be variable message signs for highways and city information boards. The target of the project is to manufacture a multicolour demonstrator board which will be evaluated with visual tests in outdoor compatible environment.

Objectives:
The basic objective is the introduction of the LCD technology into the area of large (giant) outdoor electronic multicolour matrix information boards. An efficient and stable multicolour light converter based on silkscreen inks with daylight fluorescent dyes will be developed to use the ambient light. For further improvement of the readability in sunny environment, additional measures will be introduced. The final objective is to create a public medium with low cost and low power consumption. A multicolour demonstrator board will be manufactured and evaluated with visual tests in outdoor compatible environment. The basic module concept has already been proven on monochrome displays and it has been shown that this new information board can be produced in Europe, using automated assembly technology.

Work description:
The work is divided into 5 technical work packages plus 2 for exploitation and management. WP 1 refers to the optimisation of those optical parameters which are colour independent, e.g.:
a) LC cell viewing angle improvement;
b) development of new structured foils or coatings to direct the light towards the viewer and to minimise specula reflections reducing contrast.
In month 12, the cell technology for mass production will be selected based on test cell results (M1). Final demonstrators for the optical structures shall be presented in month 18. In WP 2 the components required for sub pixel displays as well as the module assembly with jigs and tools for an automated process shall be developed. This includes also grey scale driving and test procedures. The results will be confirmed with environmental tests. 3 intermediate milestones for material and technology selection have been introduced in months 6 and 9.WP 3 is the core of the project. It covers the development of the RGB light converter suitable for silkscreen printing. The chemistry of the existing daylight fluorescent dyes has to be adapted to this special application and the performance of the blue emitting dyes has to be improved. Then silkscreen ink needed for making a multicolour display will be prepared. The results will be evaluated in intermediate milestones in months 9 and 14; final demonstrators have been planned for month 20.WP 4 covers the manufacture of a working demonstrator board with about 1m x 1m display area to be supplied in month 22.This board as well as intermediate set-ups will be tested and evaluated regarding visibility under realistic conditions by a user and a test institution in WP 5. A final report will be submitted with the end of the project.

Milestones:
Six milestones have been defined, as explained in the work plan description to allow a precise follow up of the project. The major expected results are new optical characteristics of the LC cell and the design of a light converter whose function will be to provide colour reproduction by using ambient light with a high efficiency. The final demonstrator of large outdoor LCD colour information boards will be used to test legibility under various environmental conditions.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

SAGEM SA
Address
27 Rue Leblanc
75015 Paris
France

Participants (7)

BASF AKTIENGESELLSCHAFT
Germany
Address
Carl-bosch-strasse 38
67056 Ludwigshafen
COATES SCREEN INKS GMBH
Germany
Address
Wiederholdplatz 1
90451 Nuernberg
CONCESSIONI E CONSTRUZIONI AUTOSTRADE S.P.A.
Italy
Address
Via A. Bergamini 50
00159 Roma
ELEMENT DISPLAYS DR. WIEMER GMBH
Germany
Address
Fliederweg 12
89134 Blaustein
LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES
France
Address
58, Boulevard Lefebvre
75732 Paris
MERCK KOMMANDITGESELLSCHAFT AUF AKTIEN
Germany
Address
Frankfurter Strasse 250
64293 Darmstadt
MITRON OY
Finland
Address
Tiillenlyoejaenkatu 5
30100 Forssa