We owe a greater debt to pocket calculators than we might think – for every flat-screen LCD (liquid crystal display), be it the TV at home, the mobile phone in your pocket or the computer monitor in the office, is essentially the grandchild of a pocket calculator launched by Japan’s Sharp Corporation in 1973. The EL-805 calculator (no prizes for a catchy name) was the first commercial electronic device to use an LCD screen.
The 1960s and 70s saw the so-called ‘calculator wars’ – a period of fierce price competition between manufacturers of early pocket calculators. One of the main problems of early pocket calculators was their power consumption – the fluorescent display tubes or light-emitting diodes they used required a lot of battery power, resulting in a very heavy calculator that worked for little more than an hour before it needed new batteries.
By chance, the Japanese TV channel NHK broadcasted a science documentary featuring an experimental LCD display developed by George Heilmeier at Princeton University. Among those watching it was Tomio Wada, a chemical engineer working for Sharp. Wada instantly realised that LCD displays could be the solution he’d been looking for.
But liquid crystals were a scientific curiosity that had seen very little use outside the science lab. Nobody at Sharp knew anything about them, the scientific literature was sparse to say the least, and it was not even known which compound Heilmeier had used in his display.
Despite this, Sharp decided that LCD screens were the way to go. A 20-strong team was assembled under Wada’s leadership and given the hugely ambitious goal to have a calculator with a working LCD screen on the market within 18 months.
The team tested 3,000 different liquid crystals and 500 mixtures; overcame regulatory hurdles, developed a new photolithographic etching process from scratch, to name but a few of the challenges.
The team succeeded: Within 17 months, the EL-805 was ready for launch. Weighing in at 200 g and only 2.1 cm thick it would fit in any shirt pocket – unlike the competition’s 25 cm alternative, weighing in at a full 25 kg.
Full article published in: tce 843, September 2011