The World's First Quartz Watch

The Seiko Quartz Astron 35SQ

A look back in time to the Seiko Quartz Astron 35SQ

The Seiko Quartz Astron 35SQ, the first quartz watch ever released, was a groundbreaking invention.

By 1969, the year in which the watch was released, many people already knew that quartz clocks boasted phenomenal accuracy. The problem was that they were large and bulky. The market was eagerly waiting for something smaller. Epson, working with breathtaking speed, answered the call by shrinking a quartz clock to wristwatch size. This wristwatch rewrote horologic history with its remarkable accuracy. At a time when the daily variation for mechanical watches was 20 seconds, the Astron 35SQ offered a daily variation of 0.2 seconds, meaning that it was accurate to within ±5 seconds per month.

The Astron 35SQ is one of Epson's biggest contributions to the world. It touched off a worldwide explosion in quartz watches, and for the first time in human history people around the globe had access to the correct time, anytime and anywhere.

In the process of developing the Astron 35SQ, Epson found it necessary to independently develop both a tiny crystal unit and IC unit. These were the devices on which Epson's quartz device, semiconductor, and other microdevices businesses were built.

Epson has been honored with numerous prestigious awards for the Seiko Quartz Astron 35SQ. In 2002, the IEEE (the Institute of Electrical and Electronics Engineers) honored Epson with the Corporate Innovation Recognition Award for the development of this watch. In 2004, the Astron 35SQ was registered on the List of IEEE Milestones as a key achievement in electrical engineering. Then, in 2014, it was recognized as a Mechanical Engineering Heritage product by the Japan Society of Mechanical Engineers.

The world's first tuning fork crystal unit

The crystal unit used in the Astron 35SQ was the world's first tuning-fork quartz crystal resonator. It was very small yet extremely resistant to physical shocks.

Quartz crystals electrically vibrate at a stable rate when they are subjected to an applied voltage. Crystal devices use this property to generate stable output at certain frequencies. They are used in PCs, smartphones, digital cameras, computers, automobiles and other industrial products, mobile phone and television base stations, and countless other applications. They serve as clocks that count time. They are used as references for network signals. They are even used as sensors that detect motion or changes in acceleration.

Ever since we developed the crystal unit for the Seiko Quartz Astron 35SQ, we have been working to make crystal products that are smaller yet have better performance. Today, the tiny yet powerful descendants of our first crystal unit are working quietly behind the scenes to enable everything from PC and home electronics to global networks.