Astron (wristwatch)

The Astron wristwatch, formally known as the Seiko Quartz-Astron 35SQ, was the world's first "quartz clock" wristwatch, i.e., one based on a quartz crystal oscillator. It is now registered on the List of IEEE Milestones as a key advance in electrical engineering.

The Astron was unveiled in Tokyo on December 25, 1969, after ten years of research and development at Suwa Seikosha (currently named Seiko Epson), a manufacturing company of Seiko Group. Within one week 100 gold watches had been sold, at a retail price of 450,000 yen (US$1,250) each (at the time, equivalent to the price of a medium-sized car). Essential elements included a Y-type quartz oscillator of 8192 cps, a hybrid integrated circuit, and a phase locked ultra-small stepping motor to turn its hands. The Astron was accurate to ±0.2 seconds per day, ±5 seconds per month, or one minute per year.