Editing Watch (section)

== Movement ==
[[File:Watch Mechanical Quartz Comparison.jpg|thumb|Different kinds of movements move the hands differently as shown in this 2-second exposure. The left watch has a [[24-hour analog dial]] with a mechanical 1/6s "sweep" movement, while the right one has a more common 12-hour dial and a "1s" [[Quartz clock|quartz]] movement.]]
[[File:000 0rysdf251 edited.jpg|thumb|A Russian mechanical watch movement with [[exhibition case back]], showing its movement.]]
[[File:Montre mysterieuse-IMG 4639.jpg|thumb|A so-called [[mystery watch]], it is the first transparent watch,<ref>{{cite web |url=http://ahsoc.contentfiles.net/media/assets/file/Juan_Deniz_-_The_first_transparent_watch_wm6.pdf |title=Juan F. Déniz, The first transparent watch. Antiquarian Horology Journal |access-date=7 April 2018 |archive-date=16 March 2018 |archive-url=https://web.archive.org/web/20180316214832/http://ahsoc.contentfiles.net/media/assets/file/Juan_Deniz_-_The_first_transparent_watch_wm6.pdf |url-status=dead }}</ref> c. 1890. The movement is fitted with a cylinder escapement.]]

The [[movement (clockwork)|movement]] of a watch is the mechanism that measures the passage of time and displays the current time (and possibly other information including date, month, and day).<ref>{{Cite book |url=https://books.google.com/books?id=wu-6Led6dEMC&dq=The+movement+of+a+watch+is+the+mechanism+that+measures+the+passage+of+time+and+displays+the+current+time&pg=PA723 |title=Silicon Compounds—Advances in Research and Application: 2013 Edition |date=2013-06-21 |publisher=ScholarlyEditions |isbn=978-1-4816-9238-0 |pages=723 |language=en}}</ref> Movements may be entirely mechanical, entirely electronic (potentially with no moving parts), or they might be a blend of both. Most watches intended mainly for timekeeping today have electronic movements, with mechanical hands on the [[watch face]] indicating the time.

=== Mechanical ===
{{Main|Mechanical watch}}
Compared to electronic movements, mechanical watches are less accurate, often with errors of seconds per day; are sensitive to position, temperature,<ref>{{cite web|url=http://us.tagheuer.com/#/temperature|title=Temperature|work=Advice on Your Timepiece|publisher=Tag Heuer|access-date=4 March 2011|archive-date=3 March 2011|archive-url=https://web.archive.org/web/20110303150149/http://us.tagheuer.com/#/temperature|url-status=live}}</ref> and magnetism;<ref>{{cite web|url=http://us.tagheuer.com/#/magnetism|title=Magnetism|work=Advice on Your Timepiece|publisher=Tag Heuer|access-date=4 March 2011|archive-date=3 March 2011|archive-url=https://web.archive.org/web/20110303150149/http://us.tagheuer.com/#/magnetism|url-status=live}}</ref> are costly to produce; require regular maintenance and adjustments; and are more prone to failures. Nevertheless, mechanical watches attract interest from consumers, particularly among watch collectors. [[Skeleton watch]]es are designed to display the mechanism for aesthetic purposes.

A mechanical movement uses an [[escapement]] mechanism to control and limit the unwinding and winding parts of a spring, converting what would otherwise be a simple unwinding into a controlled and periodic energy release. The movement also uses a [[balance wheel]], together with the [[balance spring]] (also known as a hairspring), to control the gear system's motion in a manner analogous to the [[pendulum]] of a [[pendulum clock]]. The [[tourbillon]], an optional part for mechanical movements, is a rotating frame for the escapement, used to cancel out or reduce [[gravity|gravitational]] bias. Due to the complexity of designing a tourbillon, they are expensive, and typically found in prestigious watches.

The [[pin-lever escapement]] (called the Roskopf movement after its inventor, [[Georges Frederic Roskopf]]), which is a cheaper version of the fully levered movement, was manufactured in huge quantities by many Swiss manufacturers, as well as by [[Timex Group USA|Timex]], until it was replaced by quartz movements.<ref>{{cite web |url=http://www.musketeer.ch/Bilder/uhr_bild/RoskAnker.jpg |title=The original pin-pallet |access-date=27 May 2012 |archive-url=https://web.archive.org/web/20120205103752/http://www.musketeer.ch/Bilder/uhr_bild/RoskAnker.jpg |archive-date=5 February 2012 |url-status=dead |df=dmy-all }}</ref><ref>{{cite web |url=http://www.musketeer.ch/watches/roskopf.html |title=The Roskopf Watch |publisher=Musketeer.ch |access-date=27 May 2012 |archive-url=https://web.archive.org/web/20120401150312/http://www.musketeer.ch/watches/roskopf.html |archive-date=1 April 2012 |url-status=dead |df=dmy-all }}</ref><ref>{{cite web|url=http://www.watkinsr.id.au/buffat.html|title=Buffat The Roskopf watch|website=Watkinsr.id.au|access-date=28 October 2017|archive-date=12 March 2018|archive-url=https://web.archive.org/web/20180312204219/http://watkinsr.id.au/buffat.html|url-status=live}}</ref>

Introduced by [[Bulova]] in 1960, [[Electric watch#Types of electric watches|tuning-fork watches]] use a type of electromechanical movement with a precise frequency (most often {{nowrap|360 Hz}}) to drive a mechanical watch. The task of converting electronically pulsed fork vibration into rotary movements is done via two tiny jeweled fingers, called pawls. Tuning-fork watches were rendered obsolete when electronic quartz watches were developed.

Traditional mechanical watch movements use a spiral spring called a [[mainspring]] as its power source that must be rewound periodically by the user by turning the watch crown. Antique pocket watches were wound by inserting a key into the back of the watch and turning it. While most modern watches are designed to run {{nowrap|40 hours}} on a winding, requiring winding daily, some run for several days; a few have 192-hour mainsprings, requiring once-weekly winding.

==== Automatic watches ====
{{Main|Automatic watch}}
[[File:Jaeger-Lecoultre-p1000838.jpg|thumb|[[Automatic watch]]: An eccentric weight, called a rotor, swings with the movement of the wearer's body and winds the spring.]]
[[File:Grand Seiko Automatic Hi-Beat.jpg|thumb|upright|A [[Grand Seiko]] Automatic watch]]

A ''self-winding'' or ''automatic'' watch is one that rewinds the mainspring of a mechanical movement by the natural motions of the wearer's body. The first self-winding mechanism was invented for pocket watches in 1770 by Abraham-Louis Perrelet,<ref>{{cite web | url=http://www.worldtempus.com/fr/encyclopedie/index-encyclopedique/lhorlogerie-dans-le-monde/lhorlogerie-europeenne-en-chine-watches-wonders/ | title=Watchmaking in Europe and China: Watches & Wonders | work=[[Richemont]] | publisher=Worldtempus |archive-url=https://web.archive.org/web/20121011232012/http://www.worldtempus.com/fr/encyclopedie/index-encyclopedique/lhorlogerie-dans-le-monde/lhorlogerie-europeenne-en-chine-watches-wonders/ |archive-date=11 October 2012}}</ref> but the first "[[self-winding watch|self-winding]]", or "automatic", wristwatch was the invention of a British watch repairer named [[John Harwood (watchmaker)|John Harwood]] in 1923. This type of watch winds itself without requiring any special action by the wearer. It uses an eccentric weight, called a winding rotor, which rotates with the movement of the wearer's wrist. The back-and-forth motion of the winding rotor couples to a [[ratchet (device)|ratchet]] to wind the mainspring automatically. Self-winding watches usually can also be wound manually to keep them running when not worn or if the wearer's wrist motions are inadequate to keep the watch wound.

In April 2013, the [[Swatch Group]] launched the ''sistem51'' wristwatch. It has a mechanical movement consisting of only 51 parts,<ref>{{cite web|url=https://www.faz.net/aktuell/technik-motor/swatch-bringt-bunte-sistem51-auf-den-markt-13003950.html|title=Vollautomatisch vom Band|author=Monika Schramm|language=de|date=29 June 2014|website=Frankfurter Allgemeine Zeitung|access-date=24 September 2024}}</ref> including 19 [[jewel bearing|jewels]] and a novel self-winding mechanism with a transparent oscillating weight.<ref>{{cite web|url=https://www.watchtime.com/blog/monochrome-monday-our-review-of-the-swatch-sistem51/|title=Reviewing the Swatch Sistem51|author=Brice Goulard|website=WatchTime|date=4 May 2016|access-date=23 September 2024}}</ref> Ten years after its introduction, it is still the only mechanical movement manufactured entirely on a fully automated assembly line, including adjustment of the balance wheel and the escapement for accuracy by [[laser]].<ref>{{cite web|url=https://www.uhrenkosmos.com/swatch-sistem51-werk-und-konstruktionsweise/|title=Swatch Sistem51 – ein Uhrwerk mit System|author=Gisbert L. Brunner|language=de|date=19 October 2023|website=uhrenkosmos.com|access-date=23 September 2024}}</ref> The low parts count and the fully automated assembly make it an inexpensive automatic Swiss watch.<ref>{{cite web|url=https://www.hodinkee.com/articles/exclusive-hands-on-look-at-the-swatch-sistem51|title=An Exclusive Look At The Swatch Sistem51, A Revolutionary Mechanical Watch|author=Stephen Pulvirent|website=hodinkee.com|date=30 April 2013|access-date=23 September 2024}}</ref>

=== Electronic ===
{{See also|Electric watch|Quartz clock}}
[[File:Csem-beta1.jpg|thumb|upright|First quartz wristwatch BETA 1 developed by CEH, Switzerland, 1967]]
Electronic movements, also known as quartz movements, have few or no moving parts, except a [[quartz]] [[crystal]] which is made to vibrate by the [[piezoelectric effect]]. A varying electric voltage is applied to the crystal, which responds by changing its shape so, in combination with some electronic components, it functions as an [[quartz oscillator|oscillator]]. It [[resonance|resonates]] at a specific highly stable frequency, which is used to accurately pace a timekeeping mechanism. Most quartz movements are primarily electronic but are geared to drive mechanical hands on the face of the watch to provide a traditional analog display of the time, a feature most consumers still prefer.{{citation needed|date=May 2024}}

In 1959 [[Seiko]] placed an order with [[Epson]] (a subsidiary company of Seiko and the 'brain' behind the quartz revolution) to start developing a quartz wristwatch. The project was codenamed 59A. By the [[1964 Summer Olympics|1964 Tokyo Summer Olympics]], Seiko had a working prototype of a portable quartz watch which was used as the time measurements throughout the event.{{citation needed|date=May 2024}}

The first prototypes of an electronic quartz wristwatch (not just {{em|portable}} quartz watches as the Seiko timekeeping devices at the Tokyo Olympics in 1964) were made by the CEH research laboratory in [[Neuchâtel]], Switzerland. From 1965 through 1967 pioneering development work was done on a miniaturized 8192&nbsp;Hz quartz oscillator, a thermo-compensation module, and an in-house-made, dedicated integrated circuit (unlike the hybrid circuits used in the later Seiko Astron wristwatch). As a result, the BETA 1 prototype set new timekeeping performance records at the International Chronometric Competition held at the [[Observatory of Neuchâtel]] in 1967.<ref>{{cite web |url=http://ethw.org/Milestones:Pioneering_Work_on_the_Quartz_Electronic_Wristwatch,_1962-1967 |title=Milestones: Pioneering Work on the Quartz Electronic Wristwatch, 1962–1967 |date=31 December 2015 |publisher=ETHW |access-date=4 December 2021 |archive-date=4 December 2021 |archive-url=https://web.archive.org/web/20211204234636/http://ethw.org/Milestones:Pioneering_Work_on_the_Quartz_Electronic_Wristwatch,_1962-1967 |url-status=live }}</ref> In 1970, 18 manufacturers exhibited production versions of the beta 21 wristwatch, including the [[Omega Electroquartz]] as well as [[Patek Philippe]], [[Rolex Oysterquartz]] and [[Piaget SA|Piaget]].

[[File:Seiko 35A.jpg|thumb|Quartz Movement of the Seiko [[Astron (wristwatch)|Astron]], 1969 (Deutsches Uhrenmuseum, Inv. 2010-006)]]

The first quartz watch to enter production was the [[Seiko]] [[Astron (wristwatch)|35 SQ Astron]], which hit the shelves on 25 December 1969, swiftly followed by the Swiss Beta 21, and then a year later the prototype of one of the world's most accurate wristwatches to date: the [[Omega Marine Chronometer]]. Since the technology having been developed by contributions from Japanese, American and Swiss,<ref>{{cite web |url=http://www.ieee-uffc.org/main/history/step.pdf |title=In the late 1960s teams of engineers working independently in Japan, Switzerland, and the United States used newly created electronic components to completely reinvent the wristwatch. |publisher=IEEE |date=2000 |access-date=7 June 2016 |url-status=dead |archive-url=https://web.archive.org/web/20151013191116/http://www.ieee-uffc.org/main/history/step.pdf |archive-date=13 October 2015 |df=dmy-all }}</ref> nobody could patent the whole movement of the quartz wristwatch, thus allowing other manufacturers to participate in the rapid growth and development of the quartz watch market. This ended – in less than a decade – almost 100 years of dominance by the mechanical wristwatch legacy. Modern quartz movements are produced in very large quantities, and even the cheapest wristwatches typically have quartz movements. Whereas mechanical movements can typically be off by several seconds a day, an inexpensive quartz movement in a child's wristwatch may still be accurate to within half a second per day – ten times more accurate than a mechanical movement.<ref>Quartz mechanisms usually have a resonant frequency of 32768&nbsp; Hz, chosen for ease of use (being 2<sup>15</sup>). Using a simple 15 stage divide-by-two circuit, this is turned into a 1 pulse per second signal responsible for the watch's timekeeping.</ref>

After a consolidation of the mechanical watch industry in Switzerland during the 1970s, mass production of quartz wristwatches took off under the leadership of the [[Swatch Group]] of companies, a Swiss conglomerate with vertical control of the production of Swiss watches and related products. For quartz wristwatches, subsidiaries of Swatch manufacture [[Watch battery|watch batteries]] ([[Renata (battery)|Renata]]), oscillators ([[Oscilloquartz]], now Micro Crystal AG) and integrated circuits (Ebauches Electronic SA, renamed [[EM Microelectronic-Marin]]). The launch of the new [[Swatch|SWATCH]] brand in 1983 was marked by bold new styling, design, and marketing. Today, the Swatch Group maintains its position as the world's largest watch company.

[[Seiko]]'s efforts to combine the quartz and mechanical movements bore fruit after 20 years of research, leading to the introduction of the Seiko [[Spring Drive]], first in a limited domestic market production in 1999 and to the world in September 2005. The Spring Drive keeps time within quartz standards without the use of a battery, using a traditional mechanical gear train powered by a spring, without the need for a balance wheel either.

In 2010, [[Miyota (watch movement manufacturer)|Miyota]] ([[Citizen Watch]]) of [[Japan]] introduced a newly developed movement that uses a 3-pronged quartz crystal that was exclusively produced for [[Bulova]] to be used in the Precisionist or Accutron II line, a new type of quartz watch with ultra-high frequency (262.144&nbsp;kHz) which is claimed to be accurate to +/− 10 seconds a year and has a smooth sweeping second hand rather than one that jumps each second.<ref>{{cite web |url=http://www.crunchgear.com/2010/03/23/bulova-introduces-the-most-accurate-watch-in-the-world-the-precisionist/ |title=Bulova introduces the most accurate watch in the world, the Precisionist |publisher=Crunch gear |date=23 March 2010 |access-date=8 July 2012 |archive-date=10 March 2011 |archive-url=https://web.archive.org/web/20110310131803/http://www.crunchgear.com/2010/03/23/bulova-introduces-the-most-accurate-watch-in-the-world-the-precisionist/ |url-status=dead }}</ref>

[[File:Junghans Mega.jpg|thumb|World's first [[radio clock]] wrist watch, [[Junghans Mega]] (analog model)]]
Radio time signal watches are a type of electronic quartz watch that synchronizes ([[time transfer]]s) its time with an external [[Radio time signal|time source]] such as in [[atomic clock]]s, time signals from [[GPS]] navigation satellites, the German [[DCF77]] signal in Europe, [[WWVB]] in the US, and others. Movements of this type may, among others, synchronize the time of day and the date, the [[leap year|leap-year]] status and the state of [[daylight saving time]] (on or off). However, other than the radio receiver, these watches are normal quartz watches in all other aspects.

Electronic watches require electricity as a power source, and some mechanical movements and hybrid electronic-mechanical movements also require electricity. Usually, the electricity is provided by a replaceable [[battery (electricity)|battery]]. The first use of electrical power in watches was as a substitute for the mainspring, to remove the need for winding. The first electrically powered watch, the Hamilton Electric 500, was released in 1957 by the [[Hamilton Watch Company]] of [[Lancaster, Pennsylvania]].

Watch batteries (strictly speaking cells, as a battery is composed of multiple cells) are specially designed for their purpose. They are very small and provide tiny amounts of power continuously for very long periods (several years or more). In most cases, replacing the battery requires a trip to a watch-repair shop or watch dealer; this is especially true for watches that are water-resistant, as special tools and procedures are required for the watch to remain water-resistant after battery replacement. Silver-oxide and lithium batteries are popular today; mercury batteries, formerly quite common, are no longer used, for environmental reasons. Cheap batteries may be alkaline, of the same size as silver-oxide cells but providing shorter life. Rechargeable batteries are used in some [[solar-powered watch]]es.

Some electronic watches are powered by the movement of the wearer. For instance, Seiko's [[Automatic quartz|kinetic-powered quartz watches]] use the motion of the wearer's arm: turning a rotating weight which causes a tiny [[Electrical generator|generator]] to supply power to charge a rechargeable battery that runs the watch. The concept is similar to that of self-winding spring movements, except that electrical power is generated instead of mechanical spring tension.

[[Solar powered watch]]es are powered by light. A [[photovoltaic cell]] on the face ([[dial (measurement)|dial]]) of the watch converts light to electricity, which is used to charge a [[rechargeable battery]] or [[capacitor]]. The movement of the watch draws its power from the rechargeable battery or capacitor. As long as the watch is regularly exposed to fairly strong light (such as sunlight), it never needs a battery replacement. Some models need only a few minutes of sunlight to provide weeks of energy (as in the Citizen [[Eco-Drive]]). Some of the early solar watches of the 1970s had innovative and unique designs to accommodate the array of solar cells needed to power them (Synchronar, Nepro, Sicura, and some models by Cristalonic, [[Alba (watch)|Alba]], Seiko, and Citizen). As the decades progressed and the efficiency of the solar cells increased while the power requirements of the movement and display decreased, solar watches began to be designed to look like other conventional watches.<ref>{{cite web|url=http://www.soluhr.com/|title=History of the Solar Wristwatch|work=Soluhr.com|access-date=17 January 2007|archive-url=https://web.archive.org/web/20070812141728/http://www.soluhr.com/|archive-date=12 August 2007|url-status=dead|df=dmy-all}}</ref>

A rarely used power source is the temperature difference between the wearer's arm and the surrounding environment (as applied in the [[Citizen Watch Co., Ltd|Citizen]] [[Eco-Drive]] Thermo).