BWC SWISS OPTEL DSM LCD 1972
This is the first in the World digital LCD watch by Optel USA introduced at the Basel Fairs in 1972. It would have been remembered as the first ever digital watch but the battle was lost to the Pulsar P1 LED due to technical challenges that delayed a successful launch of a reliable timepiece. Legend has it that the once reputable Swiss maker BWC Swiss co-funded development of the technology but IMO cooperation with the Swiss was just one of the distribution channels as the same watch can also be found with Lucien Piccard branding. In contrast to the Hamilton/Pulsar giant Optel was a small electronics entity that needed a watchbusiness partner with established retail-chain in order to succeed with sales of a time device fitted with Optel hand-soldered modules (shown exposed below).
Technology flaws were solved and the watch finally hit the market in late 1972 when Pulsar was already breaking ground. Early LCD displays were invented in the late 1960's by RCA a leading electronics corporation known for its radio and television sets. An RCA "spin-off" company called Optel was created where inventors Nuncio Luce and Louis Zanoni coordinated team efforts to develop the DSM LCD for use in digital wristwatches - read a 1973 Fortune article here. Dynamic Scattering Mode displays with white-cream digits were only made in 1972-73 and soon abandoned due to high power consumption and poor contrast. Based on information from the inventors son, Greg Zanoni, purity of the display crystals was an additional issue thus the rate of successful and reliable displays in the longterm was not satisfactory.
Common black&white (twisted nematic) Field Effect displays were introduced soon after thus DSMs are very scarce especially in working condition. The construction is pretty complicated and consists of a few layers. The top glass with conductive traces is coated black from the inside with a non-conductive layer, filled with liquid crystals and hermetically closed with a soldered metal cover. The display is fitted to the module on a plastic frame with 24 graphite-rubber conductive pads and mounted with a metal frame held with four screws. To much pressure on the screws or intensive shock results in broken corners = missing display segments. These can successfully repaired with silver epoxy as long as the epoxy does not reach the metal cover. If the black coating is broken a short will occur and result in blank display.
Pictured to the right is a 200x animation of the liquid DSM crystals that actually flow like if they were being boiled. DSM displays tend to age, dry out and loose vacuum thus perfectly floating crystals are extremely scarce. Move the mouse to the picture above (12) to see how a near perfect condition display changes to a dried out with poor contrast. Please note that swapping DSM displays between different modules (round and square) is possible but might not always work as the displays age differently without any pattern and so does the circuitry which might require some components to be exchanged to increase or decrease the voltage to a perfect match with the display. PS. Round Field Effect modules have a different layout and will not work with DSM displays which require far higher voltage.
Keywords: bwc swiss, dsm lcd, optel, lucien piccard, kuatron
Market value: 300-750$ (version, condition, box)