Casio was established in April 1946 by Tadao Kashio (樫尾 å¿ é›„, Kashio Tadao), an engineer specializing in fabrication technology. Kashio’s first major product was the yubiwa pipe, a finger ring that would hold a cigarette, allowing the wearer to smoke the cigarette down to its nub while also leaving the wearer’s hands free. Japan was impoverished immediately following World War II so cigarettes were valuable, and the invention was a success.
After seeing the electric calculators at the first Business Show in Ginza, Tokyo in 1949, Kashio and his younger brothers used their profits from the yubiwa pipe to develop their own calculators.
In the mid-1970s the first calculators appeared with the now “normal” LCDs with dark numerals against a grey background, though the early ones often had a yellow filter over them to cut out damaging UV rays. The big advantage of the LCD is that it is passive and reflects light, which requires much less power than generating light. This led the way to the first credit-card-sized calculators, such as the Casio Mini Card LC-78 of 1978, which could run for months of normal use on a couple of button cells.