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R miscellanea

R.1 Electric Lighting and Bta Light for Watches

The pioneers of watch-lighting were Allemann AD and Ernest Borel.

1956Application for patent for the use of electric lighting in watches by Ernest Borel (September 28th 1956, no. 336764 Switzerland).
11957The first watch with a display illuminated by a small lamp of 1.2 mm, is the 'Tourist Everlight' of Ad. Allemann Fils S.A. of Welschenrohr, Switzerland. Three models were shown at the 1957 Basle Fair: a steel, goldplated and 18 K gold version. A small lead battery, the 'DEAC Dry-Accumulator' had to be recharged by a normal 1.5 V battery. In the United States, the 'Robot Everlight' was distributed by Robot Time New York.
21958At the Basle Fair, the Brussels World Fair and at the Milan Fair, Ernest Borel premieres the 'Flash', a watch with a built-in coin sized accumulator to illuminate the dial. The lead accumulator can be recharged by its owner in 8 to 10 hours, by means of connecting a normal 1.5 V flashlight battery. This has to be connected to the crown (positive terminal) and the case (negative terminal). The light bulb is integrated in a plastic ring. When the lightbulb needs to be changed, only the ring needs to be replaced.

Peculiar Applications

10Tegrov Russia makes a LED imitating mechanical watch. The small light bulb illuminates a red fluorescent dial behind a red crystal. The illusion is created that actual light emitting diodes have been used in the watch.
111971Brevinex S.A. of Geneva, Switzerland, introduces the 'Etna Light Jet'. A mechanical watch with mechanical alarm, electric lighting and two power cells in the strap.
12The Mortima Light Electric.
131974The Sicura 'Instalite Electric', Volta III.
141994Seiko announces the 'LumiBrite'. When exposed under light of a certain brightness for a few minutes, the fluorescent material on the dial will glow for hours.

Radio Active Lighting, Bta Light

1958At this point of time, dials are mainly painted with radio-active materials containing strontium 90 and later on radium 226. These elements emit bta (electrons) and alpha particles which lit up other fluorescent materials used in the dials. By the 17th of December 1959, the American Committee for Atom-Energy demanded a ban on the import of these watches. Consequently, 600 Rolex 'GMT-Master' watches, containing strontium 90 and already sold in the USA, were bought back by the dealers.
1976The first commercial LCD watch with bta-light is the 'Sensor Laser', marketed in the USA after severe testing by the 'US Nuclear Regulatory Commission' (US NCR). The bta-light had been developed by Saunders-Roe Developments Ltd in Great Britain. A small glass tube would contain radio-active tritium that emits electrons which hit the molecules of the fluorescent layer on the inside of the glass tube. The light illuminates the dial. The quantity of tritium used, will last ten to twenty years. The US NRC licensed the manufacturing and sales of tritium containing products. In 1976, only Micro Display Systems, American Micro Systems and Microma had obtained such licences. In Europe, the The Nuclear Energy Agency of the Organisation for Economic Co-operation and Development (OECD-NEA), situated in Paris, regulated the use of radio-active materials in consumer products. This organisation issued the 'Radiation Protection Standards for Gaseous Tritium Light Devices' in 1973.
20Sensor Laser TriLite.

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Copyright by Pieter Doensen

email: doensen@xs4all.nl

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