Ebauches SA

4min read

In the 1960s Longines was considered by many to be at the peak of precision horology. Winning many times the chronometry competition of the observatory in Neuchâtel in different categories and providing precision timing for sports events consolidated their reputation.

The ASUAG (Allgemeine Schweizerische Uhrenindustrie AG) conglomerate was created in 1931 to help strengthen the Swiss watch industry by regrouping mostly watch movement and watch parts manufacturers. In 1971 ASUAG also incorporated 7 major watch brands: Certina, Edox, Eterna, Mido, Oris, Technos and Longines (owner of Record and Rotary), to create the General Watch Co. (1).

Knowing of the increasing global interest in ‘solid state’ systems (systems with no moving parts) for wristwatches, General Watch Co. decided to make Longines the bridgehead for their own developments in that direction. Longines had no expertise in the required areas of research, but was used to collaborate for creating electronic watches as was the case with Golay SA in Lausanne, which among others developed the electronic module of Longines ‘Ultra-Quartz‘ model. For this new and more futuristic project, Longines partnered with Ebauches SA, also part of ASUAG, collaborated with Texas Instruments Dallas and will later (starting late 1972) work together with BBC (Brown Boveri Co.) for the development of an electronic caliber with digital display. The new project launched 1971, was lead by André Beyner of Ebauches SA and was codenamed ‘Clepsydre’, meaning ‘hourglass’ and which is part of the logo of the Longines brand (2, 5).

Although serious research into the two major digital display systems LED (Light Emitting Diode) and LCD (Liquid Crystal Display) started and advanced more or less in parallel, the LED system integrated portable horology earlier and Hamilton already managed to present a working prototype in 1970. Knowing that the LED system was already exploited and the Pulsar system soon licensed and sold to numerous companies, Ebauches SA’s efforts concentrated on the adaptation of the LCD technology. The collaboration with Texas Instruments was very strategic, as the firm was amongst the first to build useful LCD displays already in 1968, but they were too large to be exploited as wrist watch displays. As for all other electronic components destined to be used in these electronic watch calibers, the main task was to miniaturise existing, experimental technology to be integrated into such a small wrist watch volume (5).

The first working and usable LCD displays used the DSM (Dynamic Scattering Mode) technology invented 1964 by George Heilmeier at the RCA Laboratories in the USA. Ebauches SA and Texas Instruments thus focused on the miniaturisation of these DSM displays and the corresponding circuitry. DSM displays were quite difficult to read, so the few manufacturers marketing this system did so only between 1972 and 1974.

Peter J. Wild. Picture credit (4)

Probably because of the intrinsic problems with the DSM displays, BBC with his leading electronics ETH engineer Peter J. Wild, was recruited to join the project in 1972. BBC had entered the research on LCD displays already in 1969 and Wild had gathered much experience in this research field (3, 5).

The LCD research at BBC was initiated by George Keller, head of the ‘Electronic Components Division’ at BBC and was done in collaboration with Roche, initially to develop displays for medical use and they collaborated with Faselec in Zurich for the electronic circuitry (3, 4).

The discovery of the 90-degree Twisted Nematic field effect (TN-cell) and its properties by Wolfgang Helfrich and Martin Schadt, physicists at Roche in 1970, redirected the focus of the research to TN-LCD displays. The invention of this more reliable LCD system had motivated Ebauches SA to join efforts with BBC (and thus Roche) and their first, miniaturised working TN-LCD-displays were incorporated into later ‘Clepsydre’ P3 prototypes shown at the Basel Fair 1973. The same year a production facility was built by BBC in Lenzburg, providing TN-LCD displays to world wide customers such as Casio for their model ‘Casiotron’, Casio’s first digital wrist watch model, starting 1974 (3).

In the sub-section you find the earliest known prototype of the ‘Clepsydre’ project and probably the earliest LCD watch known to be made outside of the USA.

Ref.:

  1. Watch-Wiki
  2. Lachat S.: Longines through Time, Editions Simonin, 2017
  3. Engineering and Technology History Wiki
  4. Wikipedia – Peter J. Wild
  5. Personal communication with a former Executive Vice-President of Ebauches SA, in charge of Research & Engineering.
  6. Longines – Argumentaire de vente LCD solid state, February 1975