Projection clock

A projection clock (also called ceiling clock) is an analogue or digital clock equipped with a projector that creates an enlarged image of the clock face or display on any surface usable as a projection screen, most often the ceiling.[1]

The clock can be placed almost anywhere if only the projected image must be seen. The image generated by most projection clocks is large enough that a nearsighted person can see it from a distance without glasses or contact lenses. Clocks usually have a conventional display on their body, in addition to the projector,

Projection clocks are also used in advertising and merchandising. High-brightness analogue projection clocks can superimpose a business' logo on top of the clock face, while there are low-brightness projection clocks designed for home use that project, for example, a logo in addition to the time.

Some projection clocks are radio-controlled, synchronising with a broadcast time standard and always displaying the right time without the need to set them. They may also display other information such as temperature and humidity.

History

Projection clocks were patented at least twice: once in 1909, and another time in 1940.[2] Both patents have expired.

Early projection clocks were universally analogue but with the widespread adoption of digital clocks, digital projection clocks became the standard.

Technology

A projection clock usually needs a backlight like an incandescent bulb or LED.

There are low-brightness and high-brightness clocks. While the projection created by low-brightness clocks can be viewed only in a darkened room, high-brightness ones can also be viewed in bright light or daylight.

Low-brightness projection clocks

Most modern projection clocks have a red LED-based projector. Additional optional features not specific to projection clocks are the inclusion of an LED or LCD display in addition to the projector, an alarm function, and synchronisation to a broadcast time standard.

High-brightness projection clocks

Modern high-brightness projection clocks are in most cases analogue and have a halogen bulb backlight. In most cases, they use a set of rotating and fixed transparent discs with hands and a face. An LCD is integrated into some clocks to combine analogue and digital information on the projected image.

Projectors used in projection clocks are similar to other projectors and use the same optical principles. They usually use lenses although some projectors use the principle of shadow theatre [dubious – discuss], vector or raster scanning.

References

  1. ^ "The 7 Best Projection Alarm Clocks". Redshed. Retrieved 12 June 2019.
  2. ^ [1] Archived April 4, 2005, at the Wayback Machine

Read other articles:

العلاقات الأوزبكستانية القبرصية

العلاقات الأوزبكستانية القبرصية أوزبكستان قبرص   أوزبكستان   قبرص تعديل مصدري - تعديل   العلاقات الأوزبكستانية القبرصية هي العلاقات الثنائية التي تجمع بين أوزبكستان وقبرص.[1][2][3][4][5] مقارنة بين البلدين هذه مقارنة عامة ومرجعية للدولتين: وج�...

 

Foreign relations of Gabon

Overview of the foreign relations of Gabon This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: Foreign relations of Gabon – news · newspapers · books · scholar · JSTOR (February 2013) (Learn how and when to remove this template message) Politics of Gabon Constitution Human rights Government President (transition...

 

Kereta api Sindang Marga

Kereta api Sindang MargaKereta api Sindang Marga saat tiba di Stasiun KertapatiInformasi umumJenis layananKereta api antarkotaStatusBeroperasiDaerah operasiDivisi Regional III PalembangMulai beroperasi6 April 1972Operator saat iniPT Kereta Api IndonesiaLintas pelayananStasiun awalKertapatiJumlah pemberhentianLihatlah di bawah.Stasiun akhirLubuklinggauJarak tempuh304,9 kmWaktu tempuh reratarata-rata 6 jam 35 menitFrekuensi perjalananSekali pergi pulang sehariJenis relRel beratPelayanan penumpa...

Thank God (Kane Brown and Katelyn Brown song)

2022 single by Kane Brown and Katelyn BrownThank GodSingle by Kane Brown and Katelyn Brownfrom the album Different Man ReleasedSeptember 12, 2022 (2022-09-12)GenreCountryLength2:54LabelRCA NashvilleSongwriter(s)Christian DavisKyle FishmanJaxson FreeJosh HogeJared MullinsProducer(s)Kane BrownDann HuffKane Brown singles chronology Grand (2022) Thank God (2022) Next to You (2023) Thank God is a song by American country music singer Kane Brown. It is a duet with his wife, Katel...

 

Harry S. Truman Scholarship

American graduate fellowship This article relies excessively on references to primary sources. Please improve this article by adding secondary or tertiary sources. Find sources: Harry S. Truman Scholarship – news · newspapers · books · scholar · JSTOR (September 2023) (Learn how and when to remove this template message) AwardHarry S. Truman ScholarshipAwarded forGraduate study in the United States for public service leadershipSponsored byHarry S. Truma...

 

Ivan Dixon

American actor, director, producer (1931–2008) Ivan DixonDixon in 1964BornIvan Nathaniel Dixon III(1931-04-06)April 6, 1931New York City, U.S.DiedMarch 16, 2008(2008-03-16) (aged 76)Charlotte, North Carolina, U.S.Alma materNorth Carolina Central UniversityOccupations Actor director producer Years active1957–1991SpouseBerlie Ray Dixon (m.1954)Children4 Dixon (left) with Steven Perry and Kim Hamilton in The Big Tall Wish, a 1960 episode of The Twilight Zone Ivan Nathaniel Dix...

Monique Smit

Dutch singer and television presenter This article is about the Dutch media personality. For the South African golfer, see Monique Smit (golfer). Monique SmitSmit in 2010BornMargaret Gertrude Mary Smit (1989-04-09) April 9, 1989 (age 35)Volendam, NetherlandsOccupation(s)Singer, television presenter Margaret Gertrude Mary (Monique) Smit (born 9 April 1989) is a Dutch singer and television presenter. Early life Monique grew up in Volendam as the younger sister of Jan Smit. After finishing ...

 

Protactile

Language used by DeafBlind people ProtactileProtactile American Sign LanguageNative toUnited StatesRegionWashington, OregonLanguage familyFrancosign FSL–MVSLAmerican SignProtactileLanguage codesISO 639-3– Protactile is a language used by deafblind people using tactile channels. Unlike other sign languages, which are heavily reliant on visual information, protactile is oriented towards touch and is practiced on the body. Protactile communication originated out of communications by Dea...

 

Ida-Viru County

County of Estonia County in EstoniaIda-Viru County Ida-VirumaaCounty FlagCoat of armsCountryEstoniaCapitalJõhviLargest townNarvaArea[1] • Total2,972 km2 (1,147 sq mi)Population (2022)[1] • Total132,736 • Rank3rd • Density45/km2 (120/sq mi)Ethnicity • Russians73.2% • Estonians18.4% • Ukrainians2.4% • other5.7%GDP[2] • Total€2.631 billio...

Transavia.com

Ada usul agar Transavia.com diganti judulnya dan dipindahkan ke Transivia (Diskusikan).Transavia IATA ICAO Kode panggil HV TRA TRANSAVIA Didirikan1965 (sebagai Transavia Limburg N.V.)Mulai beroperasi17 November 1966PenghubungAmsterdamEindhovenRotterdam/Den HaagProgram penumpang setiaFlying BlueAnak perusahaanTransavia FranceArmada42Tujuan88SloganIt's a pleasurePerusahaan indukKLMKantor pusatHaarlemmermeer, BelandaTokoh utamaMarcel de Nooijer (CEO)Situs webwww.transavia.comTransavia Airlin...

 

Classique (cyclisme)

Si ce bandeau n'est plus pertinent, retirez-le. Cliquez ici pour en savoir plus. Cet article ne s'appuie pas, ou pas assez, sur des sources secondaires ou tertiaires (avril 2023). Pour améliorer la vérifiabilité de l'article ainsi que son intérêt encyclopédique, il est nécessaire, quand des sources primaires sont citées, de les associer à des analyses faites par des sources secondaires. Les classiques sont les courses d'un jour les plus prestigieuses du calendrier international de cy...

 

Державний комітет телебачення і радіомовлення України

Державний комітет телебачення і радіомовлення України (Держкомтелерадіо) Приміщення комітетуЗагальна інформаціяКраїна  УкраїнаДата створення 2003Керівне відомство Кабінет Міністрів УкраїниРічний бюджет 1 964 898 500 ₴[1]Голова Олег НаливайкоПідвідомчі ор...

Univision Noticias

Proposed cable television channel This article is about the cable news channel. For the Univision network newscast, see Noticiero Univision. This article needs to be updated. Please help update this article to reflect recent events or newly available information. (August 2018) Television channel Univision NoticiasCountryUnited StatesBroadcast areaUnited StatesPuerto RicoHeadquartersDoral, Florida, U.S.ProgrammingLanguage(s)SpanishOwnershipOwnerUnivision CommunicationsSister channelsUnivisionL...

 

Donbas National Academy of Civil Engineering and Architecture

Engineering college in Makiyivka, Ukraine Donbas National Academy of Civil Engineering and ArchitectureДонбаська національна академія будівництва і архітектури Donbasʹka natsionalʹna akademiya budivnytstva i arkhitekturyMottoНавчаючи – навчаємосьMotto in EnglishTeaching – LearningTypeEngineering collegeRectorVasyl Kravets[1]Students8,000+LocationKramatorsk[2], Donetsk Oblast, UkraineWebsitedonnaba....

 

2014 United States gubernatorial elections

2014 United States gubernatorial elections ← 2013 November 4, 2014 2015 → 39 governorships36 states; 3 territories[1]   Majority party Minority party   Party Republican Democratic Seats before 29 21 Seats after 31 18 Seat change 2 3 Popular vote 32,353,526 29,722,192 Percentage 50.33% 46.24% Seats up 22 14 Seats won 24 11   Third party   Party Independent Seats before 0 Seats after 1 Seat change 1 Popular...

Humppa

Type of music from Finland This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: Humppa – news · newspapers · books · scholar · JSTOR (February 2009) (Learn how and when to remove this message) Finnish Humppa-Band Eläkeläiset on stage Humppa is a type of music from Finland. It is related to jazz and very fast fo...

 

Umanesimo

Disambiguazione – Se stai cercando la filosofia etico-razionale moderna, vedi Umanesimo (filosofia). L'Uomo Vitruviano di Leonardo da Vinci. Il disegno raffigura le proporzioni ideali del corpo umano, basandosi su un passo del De architectura di Vitruvio. L'Umanesimo fu un movimento culturale irradiatosi dall'Italia nel corso del XV e XVI secolo. Ispirato da autori trecenteschi quali Francesco Petrarca e in parte Giovanni Boccaccio, esso era volto alla riscoperta dei classici latin...

 

Latvijas PSR čempionāts futbolā 1958

Latvijas PSR čempionāts futbolā 1958A klase 1958 Competizione Virslīga Sport Calcio Edizione 14ª Organizzatore LFF Luogo  Unione Sovietica RSS Lettone Partecipanti 10 Risultati Vincitore  Sarkanais Metalurgs(8º titolo) Statistiche Incontri disputati 81 Gol segnati 216 (2,67 per incontro) Cronologia della competizione 1957 1959 Manuale L'edizione 1958 del massimo campionato di calcio lettone fu la 14ª come competizione della Repubblica Socialista Sovietica Lettone; ...

へき開

構造地質学や岩石学におけるへき開については「en:Cleavage (geology)」をご覧ください。 へき開（劈開、へきかい、英: cleavage）とは、結晶や岩石の割れ方がある特定方向へ割れやすいという性質のこと。鉱物学、結晶学用語である。宝石の加工や、工学の分野で重要な性質の1つ。 概要 岩石を構成する造岩鉱物は結晶構造由来の結晶面をもつ。この面では原子間の結合�...

 

Hortaleza

Not to be confused with Fortaleza. District in Madrid, SpainHortalezaDistrictCountry SpainAut. community MadridMunicipality MadridArea • Total27.4 km2 (10.6 sq mi)Population161,661 • Density5,896.9/km2 (15,273/sq mi)Madrid district number16 San Matías church 2015 Hortaleza is one of the 21 districts of the city of Madrid, Spain. History Origin The first recorded human activity in the area of Hortaleza was the existence of a nomadic or semi-nomadic ...