Quartz watch
A quartz watch uses quartz for timekeeping and electronics for the other main functions, display and power.
History
The history of quartz watches begins with the electric watches introduced by LIP/Elgin and Hamilton in 1958. These used a conventional wheel train and balance wheel with an electric contact rather than an escapement. The next major advance was the 1960 Bulova Accutron, which used a tuning fork and pawl-driven wheel train. Bulova was the first to use a transistor in a watch movement, a technology that was soon adopted by electric watches as well. The Accutron technology was licensed in 1968 to Ebauches SA as the Mosaba and later to Citizen as the Hi-Sonic.
The quartz wrist watch was actively developed throughout the 1960s and brought to market in 1969 and 1970. Many Swiss companies joined together as the Centre Electronique Horloger in Neuchâtel to develop the Beta series of movements. The initial 1967 Beta 1 used a dead beat stepper motor and achieved chronometer precision but was not practical for production. The 1968 Beta 2 switched to a pawl similar to the tuning fork movements but driven by a micro-motor. This showed greater promise and was developed for production as the Beta 21 movement.
Longines was first to announce a production quartz watch, however. The Longines Ultra-Quartz, announced August 20, 1969, used a quartz rod and micro-motor as a resonator, stepping down with a transistor and driving the wheel train with a micro-motor and pawl like the Beta 2. Referred to as "cybernetic" at the time, it did not use an integrated circuit or modern quartz resonator.
On Christmas Day, 1969, Seiko announced their Astron quartz watch. It used a quartz resonator and integrated circuit and drove the hands using a stepper motor, the hallmark of modern quartz watches. This model is usually credited today as the first quartz watch.
The Basel Fair in 1970 was positively filled with quartz watches, including Longines, Girard-Perregaux, and Omega as well as the Beta 21 members. The Beta 21 was a production version of the Beta 2, with a quartz rod resonator and integrated circuit counter but a micro-motor and pawl wheel train. The Beta 21 consortium members launching product at the fair included Bulova, Doxa, Elgin, Enicar, IWC, Longines, Rado, and Zodiac. In addition to the Longines Ultra-Quartz, fairgoers saw high-frequency quartz movements from Girard-Perregaux and Omega, the Elcron and Megaquartz.
Many other companies worked to commercialize the quartz movement after this, both inside and outside Switzerland. Swiss projects included the Neosonic system, Omega's Beta 22, and Universal Geneve. In Japan, Seiko and Ricoh were in the lead, with Citizen a few years delayed. Junghans of Germany and LIP of France would also soon deliver their own quartz technology, as would Bulova and Hamilton in the United States. In addition to analog watches, digital displays soon appeared, including mechanical, LED, and various LCD technologies. Texas Instruments brought dramatic improvements in integrated circuit technology, as did EEM and Faselec in Switzerland. Quartz crystals from Seiko, NDK, Statek, and Micro Crystal were also widely used.
Construction concept
A quartz watch is a timepiece that uses the oscillation of a quartz crystal to keep time, triggering a electrically-powered stepper motor to advance the wheel train, usually once per second. Although other timepieces (Seiko Spring Drive and Bulova Accutron, for example) include quartz crystals, these are generally not called quartz watches.
In a quartz movement, a crystal is made to vibrate. The uniform oscillation is now used to drive a motor with the help of a chip, ie an integrated circuit. This turns a gear train in the rhythm of the supplied pulses. Quartz watches do not contain a spring, balance wheel or escapement.
One advantage of this concept is the very high accuracy and the low space consumption, disadvantages are the environmental pollution by the battery and its dependence on the battery change.
With quartz watches there are essentially two display systems:
- digital display with light emitting diodes or liquid crystals
- analog hands, which are driven by a motor
Because of the required electric power most quartz watches have batteries. This makes it possible that the watch may stop suddenly - a fact which has to be urgently regarded especially at dive watches and which has once again led to develop mechanical dive watches, such as the GST Deep One by IWC.
Thermocompensation and Adjustment
Temperature plays a major role in the accuracy of a quartz movement. First- and second-generation quartz watch movements were generally not thermocompensated at all, leading to varying levels of accuracy. Even today, most quartz movements are second-generation CMOS circuits with no thermocompensation or other adjustments for accuracy.
There are three methods of fine accuracy adjustment in quartz movements:
- Automatically thermocompensated movements (e.g. Citizen High-Accuracy Quartz)
- Thermocompensated with calibration terminals (e.g. ETA Thermoline, Seiko 9F, Rolex OysterQuartz)
- Non-thermocompensated with calibration terminals (e.g. Jaeger-LeCoultre Mechaquartz)
Further developments
Also known are solar watches by Junghans, Citizen or Casio, that draw their power from solar cells.
Heuer introduced the world's first quartz chronograph watch in 1975, the LED/LCD Heuer Chronosplit. Seiko would be the first to produce an analog quartz chronograph, the Cal. 7A, with Heuer once again close behind in 1983. Frédéric Piguet and Jaeger-LeCoultre both delivered slim and compact quartz chronograph movements in 1987, the confusingly-named Meca-Quartz and Mechaquartz.
A combination of quartz precision and mechanical winding is the autoquartz technology developed by Seiko.
In 2019, Citizen introduced Calibre 0100, claimed to be the most accurate watch movement ever produced. Accurate to 1 second per year, this quartz movement uses an "AT Cut" oscillator rather than the more conventional tuning fork shape and operates at much higher frequency.
Economical aspects of the quartz watch
Because of the competition for the most accurate quartz watch and the most advanced technology, the Swiss watch industry collapsed late 1970s and early 1980s into their worst crisis (keyword: quartz crisis), from which in the meantime it nevertheless emerged strengthened again. This was mainly due to two things: the launch of the (quartz-driven) Swatch, which led the audience back to the Swiss watch, and secondly the successful renaissance of the mechanical watch in the luxury segment of the market.