The Seiko Quartz Astron, released on December 25, 1969, was a wristwatch that truly changed the world. With precision approximately 100 times that of standard mechanical watches, its quartz movements soon became widespread, bringing accurate timekeeping to everyone. Now, in 2012, the new Astron, bearing the same name, is on its way to making ultra-high precision, which goes beyond precision, commonplace.
Text by Masayuki Hirota (Chronos-Japan)
The First Revolution
This watch triggered the "quartz revolution." It was the world's first mass-produced quartz wristwatch and the ancestor of analog quartz wristwatches. Since the "Astron" trademark was registered only in Japan, there are also models without the logo. The unique design was created by Kazunari Sasaki of Suwa Seikosha. Released on December 25, 1969. Quartz (Cal. 35SQ, diameter 30mm, thickness 5.3mm). 8192Hz. 18KYG (diameter 36mm, thickness 11mm). The retail price at the time of release was 450,000 yen.
The oscillator controls the accuracy of a watch. It has been known since the time of Abraham-Louis Breguet that the higher the frequency, the better the accuracy of a watch. Since the 1950s, some watch manufacturers have adopted this method, dramatically improving the wearable accuracy of wristwatches. However, as long as the balance wheel remains a heavy component, further improvements are difficult. As a result, companies have begun to focus on technology that passes an electric current through quartz (crystal) and controls accuracy using its vibrations. With a small crystal, the frequency can theoretically be increased by several thousand times.
Suwa Seikosha (now Seiko Epson), a manufacturing company affiliated with Hattori Watch Shop (now Seiko Watch), began developing a quartz movement powered by a 1.5V battery in 59. The company eventually saw the potential for mass production using a lithography method that molds quartz oscillators with hydrofluoric acid, and eliminated the effects of shock by suspending the oscillator in a vacuum capsule, and temperature changes with a newly developed thermovaricap.
In 1963, Seiko released the Crystal Chronometer, a table clock equipped with a quartz movement. The following year, at the Neuchâtel Observatory Competition, it took second to seventh place in the board quartz clock category. The company then began to work on further miniaturization. The quartz pocket watches that the company entered won second to fifth place and first to fifth place at the Neuchâtel Observatory Competition in 1966 and 1967, respectively.
Although the quartz crystal issue was resolved, miniaturization remained a high hurdle. The device that converts the vibration of the quartz into the rotation of a hand—in other words, the motor—was large in size and consumed a lot of power. In response, Suwa Seikosha separated the motor's rotor and stator. They also developed a six-pole step motor that rotates the motor by 60 degrees by passing electricity only once per second through a coil made of 20,000 turns of 20 μm copper wire, successfully miniaturizing the motor and reducing its power consumption (total current consumption of 18 μA).
In 1968, Shoji Hattori, president of Hattori Watch Shop, saw the progress of the development and halted the tuning fork clock project that was underway in parallel, issuing a strict order to commercialize a wristwatch equipped with a quartz movement within one year. In response, the development team led by Tsuneya Nakamura finally completed 20 watches by December 1969. They were named "Astron." Shoji Hattori incorporated a space-themed design into the world's first mass-produced wristwatch equipped with a quartz movement.
In just 10 years, the Astron, released in 69, changed people's concept of time and eventually paved the way for the development of digital devices. "One day, all watches will be made with quartz." True to those words, the Seiko Quartz Astron changed the world.
