Dynamic Scattered LCD

Published on 30 November 2021 at 19:54

The first useful displays of this type were developed in the laboratories of Optel, Microma and Texas Instruments in 1967. The first application as display in a wrist watch was achieved by the Swiss 'Société des Garde Temps' in 1972. The construction of such a LCD will briefly be discussed.

The surrounding light goes through the front glass, a liquid crystal layer of 0,025 mm thickness, and is absorbed in the black back plate. On both glass plates, conductive transparent electrodes are attached. When a voltage between 10 and 20 volts is applied on the electrodes, the arrangement of the molecules is destroyed by the collisions of the moving ions, scattering the light and causing this part of the LCD to look darker than the rest of the display.

By replacing the black plate by a mirror it is possible to use the cell in a reflective mode. The segments which are not energised let the light go past, which will cause the mirror to reflect the light and compose the digits. The layer in the electric field between the electrodes scatters the light in all directions and looks dark. When no voltage at all is applied, the display is clear and the parts which are mirrored can be seen. The latter display has been applied the most. The problems with this display existed in the necessity of a transformer to produce at least 15 to 20 Volts and the fact that the level of power dissipation became so high, that new batteries were needed every eight months.

The first dynamic scattering LCDs had a display produced by Optel or Micromag.

Optel

The Optel Corporation of Princeton, New Jersey, USA, was founded in 1969 by RCA in pursuit of the development and sale of liquid crystal displays to the general public. The research was so expensive that it required three Swiss companies to participate financially. Therefore, in 1971, S.S.I.H., Landis & Gyr and Gebefina started to work together with Optel. Despite this co-operation, the project defaulted, resulting in Optel's bankruptcy on June 18th 1978.

 

The following watches used this type of display:

1972

The LCD watch is developed by a group of six watch factories named 'Société des Garde-Temps S.A.' (SGT) of La Chaux-de-Fonds, Switzerland. The following brandnames can be found on these watches: Avia S.A., Waltham International S.A. and Sandoz S.A. in Neuchâtel, Waltham Watch Co. (Walchron) of Chicago, USA, and the following Swiss companies: Titus of Bienne, Helvetia of Neuchâtel, Delvina of Geneva, Ditronic, Rodania of Grenchen, Wyler (Computime), Glycine, Elvia, Silvana, Milus of Bienne, Richard, BWC of Buttes and Zodiac of Le Locle. The watch was presented for the first time to the public on March 6th 1972 at the Basle Fair. It was equipped with a quartz crystal by Motorola and an IC by SSS (Solid State Scientific). SGT sold about 15,000 pieces.

The SGT was founded in 1968. It was an association of eleven watch making firms: Avia, E. Vuilleumier, W. Mathey, Fleurier Watch, Silvana, Solvil & Titus, Montres Helvetia, two sales subsidiaries, four manufacturing firms and a financing company.

In 1968 Avia, Invicta and Sandoz took over the Waltham Watch Co. Chicago, USA. At that time, it was the most important Swiss investment in the American watch industry.

In October 1970, two large firms joined SGT: Invicta S.A. and Sandoz S.A. SGT was able to take up third place among the Swiss watch conglomerates.

 

In 1972, at the 'Hannover Messe' in Germany, a group of five German watch factories show a new LCD watch: the 'Pallas Quarz'. These firms were: Adora of Schwabisch Gmund, Eppo, Exquisit, Ormo and Para all of Pforzheim, Germany. In the Netherlands the watch was sold under the brandname 'Lasita Quarz'.

 

The Tissot 'Datarecorder', the Hamilton 'Laser' and the Lanco 'OTX' are launched at the 1972 Basle Fair. These watches never reached the production stage.

1973

The General Time Corporation, Mesa Arizona USA, sold this watch under the brandnames 'Westclox' and 'Seth Thomas Quartz Matic'.

1974

In 1974, a group of three German and one Swiss watch factories announces its LCQ 575 watch with liquid crystal display at the Basle Fair. The members of this syndicate were: Arctos and Provita of Pforzheim, Germany and Buttes Watch Co. of Buttes, Switzerland. Only a few watches with this display are manufactured, no commercial production.

Microma

Microma Universal of Cupertino Mountain View, California, USA, was a subsidiary of the Intel Corporation. The module display was produced by Hamlin of Lake Mills, Wisconsin. Twentyfive percent of the watches were returned to the factory for repair.

The first modules contained two batteries, the latter ones only one. Starting in January 1973, Nepro becomes the exclusive distributor for Intel of the Microma LCD line in Europe. As Microma did not fulfill its contractual obligations, Nepro turned to IDS, a joint venture of General Electric and Solid State Scientific.

Texas industrie

Caliber ESA 9260 of the 'Swissonic 2000' line, produced by Ebauches S.A. (ESA), Longines and Texas Instruments with the name 'Clepsydre' reaches the market. Only very few watches were sold by Longines. In 1972, this watch won a prize as one of the hundred most advanced products of the year 1972, awarded annually by the 'Annual Research Conference and Awards'.


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