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Mechanical Television
Mechanical television or mechanical scan television is a television system that relies on a mechanical scanning device, such as a rotating disk with holes in it or a rotating mirror drum, to scan the scene and generate the video signal, and a similar mechanical device at the receiver to display the picture. This contrasts with vacuum tube electronic television technology, using electron beam scanning methods, for example in cathode ray tube (CRT) televisions. Subsequently, modern solid-state liquid-crystal displays (LCD) are now used to create and display television pictures. Mechanical-scanning methods were used in the earliest experimental television systems in the 1920s and 1930s. One of the first experimental wireless television transmissions was by John Logie Baird on October 2, 1925, in London. By 1928 many radio stations were broadcasting experimental television programs using mechanical systems. However the technology never produced images of sufficient quality to become ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Set
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using it as a computer monitor. Introduced in the late 1920s in Mechanical television, mechanical form, television sets became a popular consumer product after World War II in electronic form, using cathode ray tube (CRT) technology. The addition of color to broadcast television after 1953 further increased the popularity of television sets in the 1960s, and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for the first recorded media in the 1970s, such as , VHS and later DVD. It has been used as a display device since the first generation of (e.g. Timex Sinclair 1000) and dedicated video game consoles (e.g. Atari) in the 1980s. By the early 2010s, flat-panel television incorp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It seldom occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium – from Greek ( 'Moon') – was discovered in 1817 by , who noted the similarity of the new element to the previously discovered tellurium (named for the Earth). Selenium is found in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known but rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brussels International 1910
The Brussels International Exposition (french: Exposition Universelle et Internationale de Bruxelles, nl, Wereldtentoonstelling te Brussel) of 1910 was a world's fair held in Brussels, Belgium, from 23 April to 1 November 1910. This was just thirteen years after Brussels' previous world's fair. It received 13 million visitors, covered and lost 100,000 Belgian Francs. Location The grounds and buildings were partly located around the ''Solbosch'' district (in the City of Brussels' southern extension), and partly in the Parc du Cinquantenaire/Jubelpark (a remainder of the 1897 World's Fair), where the fine art's exhibition took place. The colonial exhibition was hosted in the newly built , today's Royal Museum for Central Africa, in the suburb of Tervuren. Another major site for the exhibition was the Mont des Arts/Kunstberg in central Brussels, although this site was largely demolished during the post-war construction process of Brusselisation. File:Algemeens Wereldtento ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palais De Justice, Brussels
The Palace of Justice of Brussels (french: Palais de Justice de Bruxelles, ; Dutch: ) or Law Courts of Brussels, nl, Rechtbank van Brussel is a courthouse in Brussels, Belgium. It is the country's most important court building, seat of the judicial ''arrondissement'' of Brussels, as well as of several courts and tribunals, including the Court of Cassation (Belgian supreme court), the Court of Assizes (highest criminal court), the Court of Appeal of Brussels (appellate court), the Tribunal of First Instance of Brussels (general jurisdiction), and the Bar Association of Brussels. Designed by the architect Joseph Poelaert, in an eclectic style of Greco-Roman inspiration, to replace an older courthouse, the current building was erected between 1866 and 1883. With a ground surface of , the edifice is reputed to be the largest constructed in the 19th century and remains one of the largest of its kind. The total cost of the construction, land, and furnishings was somewhere in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Ruhmer
Ernst Walter Ruhmer (15 April 1878 – 8 April 1913) was a German physicist. He was best known for investigating practical applications making use of the light-sensitivity properties of selenium, which he employed in developing wireless telephony using line-of-sight optical transmissions, sound-on-film audio recording, and television transmissions over wires. Career Ruhmer's father was an inventor and manufacturer. From 1897 to 1900 he studied mathematics and natural sciences in Berlin, and the next year continued his studies in Giessen. His early work included extensive research in developing selenium cells that were more sensitive, and faster reacting, to the effects of light illumination. In December 1902 he and Salomon Kalischer were issued German patent 151,971 for their method of producing photographic images by exposing electrically conductive selenium-coated plates. Ruhmer also designed a light-sensitive control switch, using a selenium cell, which was successfully used to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Ruhmer Demonstrating Simple Television System (1909)
Ernst is both a surname and a given name, the German, Dutch, and Scandinavian form of Ernest. Notable people with the name include: Surname * Adolf Ernst (1832–1899) German botanist known by the author abbreviation "Ernst" * Anton Ernst (1975-) South African Film Producer * Alice Henson Ernst (1880-1980), American writer and historian * Britta Ernst (born 1961), German politician * Cornelia Ernst, German politician * Edzard Ernst, German-British Professor of Complementary Medicine * Emil Ernst, astronomer * Ernie Ernst (1924/25–2013), former District Judge in Walker County, Texas * Eugen Ernst (1864–1954), German politician * Fabian Ernst, German soccer player * Gustav Ernst, Austrian writer * Heinrich Wilhelm Ernst, Moravian violinist and composer * Jim Ernst, Canadian politician * Jimmy Ernst, American painter, son of Max Ernst * Joni Ernst, U.S. Senator from Iowa * K.S. Ernst, American visual poet * Karl Friedrich Paul Ernst, German writer (1866–1933) * Ken Ernst, U.S. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Washington Star
''The Washington Star'', previously known as the ''Washington Star-News'' and the Washington ''Evening Star'', was a daily afternoon newspaper published in Washington, D.C., between 1852 and 1981. The Sunday edition was known as the ''Sunday Star''. The paper was renamed several times before becoming ''Washington Star'' by the late 1970s. For most of that time, it was the city's newspaper of record A newspaper of record is a major national newspaper with large circulation whose editorial and news-gathering functions are considered authoritative and independent; they are thus "newspapers of record by reputation" and include some of the o ..., and the longtime home to columnist Mary McGrory and cartoonist Clifford K. Berryman. On August 7, 1981, after 128 years, the ''Washington Star'' ceased publication and filed for bankruptcy. In the bankruptcy sale, ''The Washington Post'' purchased the land and buildings owned by the ''Star'', including its printing presses. History '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerr Effect
The Kerr effect, also called the quadratic electro-optic (QEO) effect, is a change in the refractive index of a material in response to an applied electric field. The Kerr effect is distinct from the Pockels effect in that the induced index change is directly proportional to the ''square'' of the electric field instead of varying linearly with it. All materials show a Kerr effect, but certain liquids display it more strongly than others. The Kerr effect was discovered in 1875 by Scottish physicist John Kerr. Two special cases of the Kerr effect are normally considered, these being the Kerr electro-optic effect, or DC Kerr effect, and the optical Kerr effect, or AC Kerr effect. Kerr electro-optic effect The Kerr electro-optic effect, or DC Kerr effect, is the special case in which a slowly varying external electric field is applied by, for instance, a voltage on electrodes across the sample material. Under this influence, the sample becomes birefringent, with different indices ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicol Prism
A Nicol prism is a type of polarizer, an optical device made from calcite crystal used to produce and analyse plane polarized light. It is made in such a way that it eliminates one of the rays by total internal reflection, i.e. the ordinary ray is eliminated and only the extraordinary ray is transmitted through the prism. It was the first type of polarizing prism, invented in 1828 by William Nicol (1770–1851) of Edinburgh. It consists of a rhombohedral crystal of Iceland spar (a variety of calcite) that has been cut at an angle of 68° with respect to the crystal axis, cut again diagonally, and then rejoined as shown, using a layer of transparent Canada balsam as a glue. Unpolarized light ray enters through the left face of the crystal, as shown in the diagram, and is split into two orthogonally polarized, differently directed rays by the birefringence property of calcite. The ''ordinary'' ray, or ''o''-ray, experiences a refractive index of ''n''o = 1.658 in the calcite and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resistive Opto-isolator
Resistive opto-isolator (RO), also called photoresistive opto-isolator, vactrol (after a genericized trademark introduced by Vactec, Inc. in the 1960s), analog opto-isolatorIn PerkinElmer literature. or lamp-coupled photocell, is an optoelectronic device consisting of a source and detector of light, which are optically coupled and electrically isolated from each other. The light source is usually a light-emitting diode (LED), a miniature incandescent lamp, or sometimes a neon lamp, whereas the detector is a semiconductor-based photoresistor made of cadmium selenide (CdSe) or cadmium sulfide (CdS). The source and detector are coupled through a transparent glue or through the air. Electrically, RO is a resistance controlled by the current flowing through the light source. In the dark state, the resistance typically exceeds a few MOhm; when illuminated, it decreases as the inverse of the light intensity. In contrast to the photodiode and phototransistor, the photoresistor can operate i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nipkow Disk
A Nipkow disk (sometimes Anglicized as Nipkov disk; patented in 1884), also known as scanning disk, is a mechanical, rotating, geometrically operating image scanning device, patented in 1885 by Paul Gottlieb Nipkow. This scanning disk was a fundamental component in mechanical television, and thus the first televisions, through the 1920s and 1930s. Operation The device is a mechanically spinning disk of any suitable material (metal, plastic, cardboard, etc.), with a series of equally-distanced circular holes of equal diameter drilled in it. The holes may also be square for greater precision. These holes are positioned to form a single-turn spiral starting from an external radial point of the disk and proceeding to the center of the disk. When the disk rotates, the holes trace circular ring patterns, with inner and outer diameter depending on each hole's position on the disk and thickness equal to each hole's diameter. The patterns may or may not partially overlap, depending on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephane
Henry Sutton (4 September 1855, Ballarat, Victoria – 28 July 1912) was an Australian designer, engineer, and inventor credited with contributions to early developments in electricity, aviation, wireless communication, photography and telephony. Branch is Sutton's great-granddaughter Early life Family Henry Sutton, the second of the eleven children of Richard Henry Sutton (1831 – 1876), and Mary Sutton (1835 – 1894), née Johnson, was born in a tent on the Ballarat goldfields on 4 September 1855. He had three brothers, with whom he was associated in the ''Sutton Brothers'' musical business originally centred on Ballarat,Sutton's Proprietary, Limited, ''The Ballarat Star'', (Saturday, 29 December 1900), p.1 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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