CBS Corporation is an American mass media corporation focused on commercial broadcasting and television production, with most of its operations in the United States. The current President and Acting CEO is Joseph Ianniello. Sumner Redstone, owner of National Amusements, controls CBS by way of his majority ownership of the company's Class A voting stock, it is the world's eighth largest entertainment company in terms of revenue after The Walt Disney Company, NBCUniversal, WarnerMedia, Bertelsmann and Sony Corporation. The company began trading on the NYSE on January 3, 2006; until the corporation was known as Viacom, is the legal successor to said company. A new company, keeping the Viacom name, was spun off from CBS. CBS, not Viacom, retains control of over-the-air television broadcasting, TV production and distribution, pay-cable, basic cable, recording owned by the larger company. CBS has its headquarters in the CBS Building, Manhattan, New York City, United States. Viacom was created in 1971 as the television syndication division of CBS, was spun off in 1971.
However, in 1999, Viacom acquired its former parent, by this time named CBS Corporation Westinghouse Electric. The prior CBS Corporation owned CMT and The Nashville Network, which remained Viacom properties after the 2005 split, but the prior CBS did not own UPN, Paramount Television, Paramount Parks, or Simon and Schuster. In March 2005, Viacom announced plans of looking into splitting the company into two publicly traded companies, amid issues of the stock price stagnating. On June 14, 2005, the Viacom Board of Directors approved the split of the company into two firms; the CBS Corporation name would be revived for one of the companies, to be headed by longtime television executive Leslie Moonves, would include CBS, UPN, Infinity Broadcasting, Viacom Outdoor, Showtime Networks, Paramount's television studio. The split was structured such that the new Viacom was spun off from the old Viacom, renamed CBS Corporation. In a sense, this was a repeat of the 1971 spinoff. However, in this case, CBS retained all of the prior firm's broadcast TV assets, including its various syndication companies.
With the split, the two new companies began trading on the NYSE on January 3, 2006. Investors anticipated Viacom benefiting from the split, but instead, it dropped 20 percent, while CBS rose 9 percent. Announced in January 2006, CBS and DIC Entertainment signed a multi-year deal in which DIC bought the Saturday morning airtime as "CBS's Saturday Morning Secret Slumber Party". In June 2006, DiC added a production partner AOL's KOL. Thus, this block would be called "KOL's Saturday Morning Secret Slumber Party on CBS". On January 24, 2006, CBS Corporation, Warner Bros. announced that they were to create a new broadcast network, The CW Television Network. The network debuted on September 18, 2006; the network formally debuted on September 20 with the 2 hour premiere of America's Next Top Model. The network is the result of a merger of The WB and UPN. CBS Corporation and Time Warner each own 50% of the network. Tribune Broadcasting and CBS Corporation will contribute its stations as new network affiliates.
Three days after the announcement of The CW, on January 27, CBS announced that it was selling its Paramount Parks division. On May 23, 2006, CBS Corporation sold Paramount Parks to the Cedar Fair Entertainment Company. With this acquisition, Cedar Fair became the third-largest theme park operator. On June 30, 2006, Cedar Fair announced that it has completed its acquisition of Paramount Parks from CBS Corporation in a cash transaction valued at US$1.24 billion. The transaction included a 10-year license that allowed Cedar Fair to use the Paramount name in the parks through the 2017 season. On February 7, 2007, CBS announced it was selling seven stations in Providence, Rhode Island, Texas, Salt Lake City and West Palm Beach, Florida to Cerberus Capital Management for US$185 million, it sold another station, WFRV-TV in Green Bay and its satellite station, WJMN-TV in Escanaba, Michigan, to Liberty Media on February 13, 2007. News reports estimate the deal at about US$234 million. CBS is swapping the stations and US$170 million in cash for 7.59 million shares of CBS common stock held by Liberty Media.
On February 26, CBS announced that it will invest in Electric Sheep, a virtual world content developer. CBS hired Electric Sheep to develop some projects, including the creation of "The L-Word in Second Life". CBS shot a commercial within the virtual world Second Life to promote its show Two and a Half Men. Another project that Electric Sheep was working on for CBS was a Star Trek-themed area in Second Life. By investing in Electric Sheep, CBS hoped to expand its activity "beyond the living room". On March 20, CBS/CSTV had acquired an online high school sports network. On April 12, CBS Corporation announced the creation of the CBS Interactive Audience Network. On May 30, CBS Interactive bought Last.fm for £140 million. On May 15, 2008, CBS Interactive announced that it had agreed t
William Henry "Hank" Green II is an American video blogger, internet producer, musician and entrepreneur. He produces the YouTube channel Vlogbrothers, where he and his brother, John Green upload videos, as well as for creating and hosting the educational YouTube channels Crash Course and SciShow. Green co-created VidCon, the world's largest conference about online videos, with his brother John, created NerdCon: Stories, a conference focused on storytelling, he is the co-creator of The Lizzie Bennet Diaries, a web series adaptation of Pride and Prejudice in the style of video blogs. He is the founder of the environmental technology blog EcoGeek and the Internet Creators Guild, co-founder of merchandise company DFTBA Records, crowdfunding platform Subbable—acquired by Patreon in 2015—game company DFTBA Games, online video production company Pemberley Digital, which produces video blog adaptations of classic novels in the public domain. Green's debut novel, An Absolutely Remarkable Thing, was published on September 25, 2018.
Green was born to Mike and Sydney Green in Birmingham and his family soon moved to Orlando, where he was raised. He graduated from Winter Park High School in 1998 and earned a B. S. in Biochemistry from Eckerd College and a M. S. in Environmental Studies from the University of Montana. His master's thesis was entitled "Of Both Worlds: How the Personal Computer and the Environmental Movement Change Everything". From January 1 to December 31, 2007, Hank and his brother John ran a video blog project titled Brotherhood 2.0. The original project ran every week day for the entire year, with the premise that the brothers would cease all text-based communication for the year and instead converse by daily video blogs, made available to the public via their YouTube channel Vlogbrothers and on their website. In 2008, John and Hank met up with their fans, known as "Nerdfighters"; the first gathering was a last-minute decision, but despite the short three-day notice, nearly a hundred people attended. In August and Hank were invited to the Google office in Chicago to talk about the project.
That same day, they filled the Harold Washington Library with about four hundred young adults. Following John's book tour for his third novel, Paper Towns, the brothers went on a national tour in November. With events in 17 different cities, they met Nerdfighters at local libraries and community centers. During this tour, Green released his first album of Nerdfighter-themed songs, titled So Jokes; the Green brothers have been interviewed on PotterCast, have been recurring keynote speakers at the Harry Potter fan convention LeakyCon. The Brotherhood 2.0 project succeeded in its original mission. The two brothers have come to communicate more with each other, have a larger influence in each other's lives than before the project was initiated; the brothers talked on the phone once or twice a year before Brotherhood 2.0, according to Hank's wife Katherine, they now "talk every day." John and Hank continued to post vlogs every Friday on their channel. Their video topics vary from explanations of current events, reunion videos, joke videos, rant videos, thoughts from various places, Question Tuesdays, random topics.
As of December 29, 2017, they have posted 1,565 videos. The channel has more than 3,000,000 subscribers, their videos have been watched over 720,000,000 times. In 2007, brothers John and Hank introduced the annual charity project titled the Project for Awesome, a project in which YouTube users take two days, traditionally December 17 and 18, to create videos promoting charities or nonprofit organizations of their choosing; the total amount of money raised. In 2015 a record $1,546,384 was raised. In January 2012, Hank and John Green created the educational YouTube channel Crash Course, as part of the site's Original Channel Initiative; the channel features several educational courses based on the high school curriculum, first launched with series focusing on Biology and World History. According to John, the brothers see Crash Course "as an introduction, as a way to get kids excited about learning, not as an attempt to replace traditional classroom materials." Their goal is to create "resources that allow for more valuable interaction in the classroom," with hopes that the channel will one day span the entire high school curriculum.
The channel was hosted by the two brothers, with Hank focusing on the science courses and John teaching the humanities courses. The channel has since expanded to welcome new hosts such as Craig Benzine, Phil Plait, Emily Graslie into its roster, has launched new courses such as Astronomy and Philosophy; as part of YouTube Kids, a separate Crash Course: Kids channel was launched in March 2015, with Sabrina Cruz hosting a Science course geared toward a younger audience. Crash Course has received praise from teachers alike, it has been awarded grants by Bill Gates' bgC3, has struck a partnership with PBS Digital Studios to continue developing more series, although the majority of its funding comes from viewer support via Patreon. Green created the science YouTube channel SciShow in January 2012, like Crash Course, was initially funded by the online video website; the channel features a series of videos focused on several scientific fields such as chemistry and biology, as well as interviews and trivia shows with experts.
Green aims for SciShow's content to be approachable and to dispel the idea that science is an inherently difficult subject. Like Crash Course, SciShow is meant to be supplementary to the traditio
Los Angeles the City of Los Angeles and known by its initials L. A. is the most populous city in California, the second most populous city in the United States, after New York City, the third most populous city in North America. With an estimated population of four million, Los Angeles is the cultural and commercial center of Southern California; the city is known for its Mediterranean climate, ethnic diversity and the entertainment industry, its sprawling metropolis. Los Angeles is the largest city on the West Coast of North America. Los Angeles is in a large basin bounded by the Pacific Ocean on one side and by mountains as high as 10,000 feet on the other; the city proper, which covers about 469 square miles, is the seat of Los Angeles County, the most populated county in the country. Los Angeles is the principal city of the Los Angeles metropolitan area, the second largest in the United States after that of New York City, with a population of 13.1 million. It is part of the Los Angeles-Long Beach combined statistical area the nation's second most populous area with a 2015 estimated population of 18.7 million.
Los Angeles is one of the most substantial economic engines within the United States, with a diverse economy in a broad range of professional and cultural fields. Los Angeles is famous as the home of Hollywood, a major center of the world entertainment industry. A global city, it has been ranked 6th in the Global Cities Index and 9th in the Global Economic Power Index; the Los Angeles metropolitan area has a gross metropolitan product of $1.044 trillion, making it the third-largest in the world, after the Tokyo and New York metropolitan areas. Los Angeles hosted the 1932 and 1984 Summer Olympics and will host the event for a third time in 2028; the city hosted the Miss Universe pageant twice, in 1990 and 2006, was one of 9 American cities to host the 1994 FIFA men's soccer World Cup and one of 8 to host the 1999 FIFA women's soccer World Cup, hosting the final match for both tournaments. Home to the Chumash and Tongva, Los Angeles was claimed by Juan Rodríguez Cabrillo for Spain in 1542 along with the rest of what would become Alta California.
The city was founded on September 4, 1781, by Spanish governor Felipe de Neve. It became a part of Mexico in 1821 following the Mexican War of Independence. In 1848, at the end of the Mexican–American War, Los Angeles and the rest of California were purchased as part of the Treaty of Guadalupe Hidalgo, becoming part of the United States. Los Angeles was incorporated as a municipality on April 4, 1850, five months before California achieved statehood; the discovery of oil in the 1890s brought rapid growth to the city. The completion of the Los Angeles Aqueduct in 1913, delivering water from Eastern California assured the city's continued rapid growth; the Los Angeles coastal area was settled by the Chumash tribes. A Gabrieleño settlement in the area was called iyáangẚ, meaning "poison oak place". Maritime explorer Juan Rodríguez Cabrillo claimed the area of southern California for the Spanish Empire in 1542 while on an official military exploring expedition moving north along the Pacific coast from earlier colonizing bases of New Spain in Central and South America.
Gaspar de Portolà and Franciscan missionary Juan Crespí, reached the present site of Los Angeles on August 2, 1769. In 1771, Franciscan friar Junípero Serra directed the building of the Mission San Gabriel Arcángel, the first mission in the area. On September 4, 1781, a group of forty-four settlers known as "Los Pobladores" founded the pueblo they called El Pueblo de Nuestra Señora la Reina de los Ángeles,'The Town of Our Lady the Queen of the Angels'; the present-day city has the largest Roman Catholic Archdiocese in the United States. Two-thirds of the Mexican or settlers were mestizo or mulatto, a mixture of African and European ancestry; the settlement remained a small ranch town for decades, but by 1820, the population had increased to about 650 residents. Today, the pueblo is commemorated in the historic district of Los Angeles Pueblo Plaza and Olvera Street, the oldest part of Los Angeles. New Spain achieved its independence from the Spanish Empire in 1821, the pueblo continued as a part of Mexico.
During Mexican rule, Governor Pío Pico made Los Angeles Alta California's regional capital. Mexican rule ended during the Mexican–American War: Americans took control from the Californios after a series of battles, culminating with the signing of the Treaty of Cahuenga on January 13, 1847. Railroads arrived with the completion of the transcontinental Southern Pacific line to Los Angeles in 1876 and the Santa Fe Railroad in 1885. Petroleum was discovered in the city and surrounding area in 1892, by 1923, the discoveries had helped California become the country's largest oil producer, accounting for about one-quarter of the world's petroleum output. By 1900, the population had grown to more than 102,000; the completion of the Los Angeles Aqueduct in 1913, under the supervision of William Mulholland, assured the continued growth of the city. Due to clauses in the city's charter that prevented the City of Los Angeles from selling or providing water from the aqueduct to any area outside its borders, many adjacent city and communities became compelled to annex themselves into Los Angeles.
Los Angeles created the first municipal zoning ordinance in the United States. On September 14, 1908, the Los Angeles City Council promulgated residential and industrial land use zones; the new ordinance established three residential zones of a single type, where industrial uses were
Troye Sivan Mellet, known professionally as Troye Sivan, is a South African-born Australian singer, songwriter and YouTuber. After gaining popularity as a singer on YouTube and in Australian talent competitions, Sivan signed with EMI Australia in 2013 and released his debut extended play, TRXYE, which peaked at number five on the U. S. Billboard 200, its lead single, "Happy Little Pill", reached number 10 on Australian music charts. In 2015, he released his second extended play Wild followed by his debut studio album Blue Neighbourhood, whose lead single "Youth" became Sivan's first single to enter the top 40 of the Billboard Hot 100 chart, peaking at number 23, his second studio album Bloom reached number three in Australia and number four on the Billboard 200 chart. Its lead single "My My My!" became Sivan's second number-one single on the Billboard Dance Club Songs chart. As an actor, Sivan portrayed the younger version of the titular character in the 2009 X-Men film X-Men Origins: Wolverine and starred as the title character in the Spud film trilogy.
As a YouTube personality, Sivan used to upload video blogs and, as of 2016, has over 4 million subscribers and over 241 million total views. His video, "The'Boyfriend' Tag", with fellow vlogger Tyler Oakley earned them a Teen Choice Award in the "Choice Web Collaboration" category. In October 2014, Time named Sivan as one of the "25 Most Influential Teens of 2014". In 2018, he received a Golden Globe nomination for Best Original Song for "Revelation", from the film Boy Erased, in which he had a supporting acting role. Sivan was born in the son of Laurelle and Shaun Mellet, his family moved to Australia. Sivan grew up living in Perth, Western Australia with his parents and three siblings Steele and Sage, his father is a real estate agent and his mother is a homemaker. He is Jewish. Sivan attended Carmel School, a private Modern Orthodox school, until 2009 when he started distance education. Sivan's musical career started when he sang at the 2007 and 2008 Channel Seven Perth Telethon, his 2006 performance included a duet with Australian Idol winner Guy Sebastian.
Sivan made it to the finals of StarSearch 2007. His debut EP, Dare to Dream, was released in June 2007. In February 2010, Sivan opened "We Are the World 25 for Haiti", the collaborative music charity video produced by Lisa Lavie to help raise money for the victims of the 2010 Haiti earthquake, his most recent hit "Youth", from his Blue Neighbourhood album that he released in 2015 reached number 23 in the billboard Top 40 single. On 5 June 2013, Sivan was signed to EMI Australia, a Universal Music Australia label, but kept it a secret until a year later. On 15 August 2014 he released a five-song EP entitled TRXYE, led by its first single "Happy Little Pill", released on 25 July 2014. TRXYE debuted at No. 1 on iTunes in over 55 countries. The album debuted at No. 5 on the Billboard 200 the following week, scoring Sivan his first Top 10 album. "Happy Little Pill" peaked at number 10 on the ARIA Singles Chart and was certified gold by the Australian Recording Industry Association for shipments exceeding 35,000 copies.
Sivan released his second major-label EP, Wild, on 4 September 2015. The EP was supported by a music video trilogy entitled Blue Neighbourhood, comprising the three songs "Wild", "Fools" and "Talk Me Down" and released from September 2015 to December 2015. Additionally, the EP served as an introduction to his album Blue Neighbourhood, released on 4 December 2015. Sivan supported his debut studio album Blue Neighbourhood and his EP Wild with his first tour, 2015's Troye Sivan Live. Sivan further supported his debut studio album with 2016's Blue Neighbourhood Tour and Suburbia Tour. On 26 May 2017, Troye collaborated with Martin Garrix to produce the song called There for You. On 10 January 2018, Sivan released the single "My My My!", along with an accompanying music video. He confirmed that his second album was inspired by his boyfriend, an American model named Jacob Bixenman; the song is a notable contrast from his earlier work, with Pitchfork commenting on his "assured" vocals and NPR Music describing it as "an infectious celebration of sexual desire".
NPR Music notes the significance of the song and music video displaying confidence in Sivan's sexuality, writing "t's not every day you see a young, queer kid get to be himself in a music video, Sivan makes us want to dance along with him." Sivan's first live performance of the song was on 20 January as the musical guest on Saturday Night Live in an episode hosted by Jessica Chastain. Sivan confirmed that his new album would feature a collaboration with long-time friend Ariana Grande, titled "Dance to This". "Bloom" was released as the third single on 2 May 2018, following "The Good Side". That month, he announced that his second studio album is titled Bloom, while accompanying Taylor Swift as a guest performer at her concert in Pasadena during her Reputation Stadium Tour; the album was released on 31 August 2018. The album's final pre-release track, "Animal", was launched on 9 August 2018. In 2018, Sivan received a Golden Globe nomination for Best Original Song for "Revelation", which he recorded and co-wrote for the film Boy Erased.
He was shortlisted for an Academy Award for the song. In October 2018, Sivan collaborated with British singer-songwriter Charli XCX on the single "1999". Sivan's music videos feature LGBTQ relationships between the characters. TRXYE's trilogy followed the narrative of t
Vlogbrothers is a video blog channel on YouTube. The Internet-based show hosted by the Green brothers: John Green and Hank Green; the first incarnation of the brothers' online broadcasting was the "Brotherhood 2.0" project, preceding the establishment of the pair's regular vlogging activity through the Vlogbrothers channel. The Vlogbrothers channel was the first in what would become a larger portfolio of YouTube channels created and developed by the Greens, sparking a community of fans and supporters of Vlogbrothers, known individually as Nerdfighters, collectively as Nerdfighteria. Subscribers of the brothers on YouTube are the base of the online community Nerdfighteria; the Green brothers encourage their viewers to become a community by creating websites and various projects, like the Project for Awesome, as a way to engage with their subscribers. Vlogbrothers is owned by Complexly, solely owned by Hank, but now jointly owned by both Greens; the Greens state that their vlog has no consistent format: "Really, it's not about anything in particular.
Whether we're talking about our lives, making each other laugh, or trying to get something more important across, people seem to enjoy it." The channel passed one million subscribers on March 5, 2013. As of 2018, the brothers post two videos per week onto their Vlogbrothers channel. John Green posts a video on Tuesday, Hank Green on Friday; the Green brothers inspired by the show with zefrank, devised the Brotherhood 2.0 project late in 2006. The project was launched on January 1, 2007, based on the premise that the brothers would cease all text-based communication for one year and, converse by video blogs every weekday; the project was made available to the public on YouTube, as well as through the brothers' own Brotherhood 2.0 website. On July 18, 2007, Hank Green uploaded a video of himself playing and singing his song "Accio Deathly Hallows" in honor of the seventh Harry Potter book; this video was the first Vlogbrothers video to make the front page of YouTube, the starting point of the brothers' success as vloggers.
Toward the end of 2007, the brothers launched the first Project For Awesome campaign, in which YouTubers created innovative videos promoting their favorite charity, with the aim that their promoted charity gains more awareness, donations from viewers. The Brotherhood 2.0 Project ended on December 31, 2007. However, the brothers decided to continue uploading videos on YouTube due to their popularity and growing fan base. In their December 31, 2007 video, the brothers revealed their decision to continue vlogging though the project had ended. Following the conclusion of Brotherhood 2.0, a website was set up for their community, known as Nerdfighters. The website was maintained by Hank Green, but is now updated and moderated by a group of community volunteers known as the "Ningmasters". New projects, discussions and forums made by the Vlogbrothers fan community are uploaded daily; the brothers' videos continue to be the basis of the online community known as "Nerdfighteria". Continuing the trend of their previous charitable endeavors, the Greens rallied their viewers to make micro-donations on Kiva.org.
The Nerdfighters lending team was launched in September 2008. As of March 2015, the Kiva Nerdfighters group ranks 7th on the site for total money loaned through total domestic and international microloans, it has 48,000 members who have loaned a collective total of over $5.3 million. On January 20, 2010, John Green went on paternity leave, Maureen Johnson made videos in his place until his return the following month, when he introduced his son, Henry. Hank Green was interviewed by Forbes in May 2011. During 2011 and 2012, the Green brothers had their Vlogbrothers videos featured on media outlets such as CBS News and Huffington Post. On September 14, 2012, Hank Green made a video celebrating the 1000th video on the Vlogbrothers channel that commemorated the brothers' experiences over the previous 5 years. On January 15, 2013, they featured in "An Evening of Awesome at Carnegie Hall" celebrating the anniversary of John's novel The Fault in Our Stars; the two-hour live streamed event featured The Mountain Goats, Kimya Dawson, Neil Gaiman.
In February, John Green participated in a Google+ Hangout with Barack Obama during which John's wife, Sarah Urist Green appeared. Prior to this, she had not been seen on camera or in any of his blogs, preferring not to join her husband on camera, her elusive attitude gained her the nickname "The Yeti". On March 5, the channel hit both brothers live-tweeted the occasion. On June 25, John Green went on paternity leave for the birth of his second child and six guest hosts made videos in his place, including Hannah Hart, Grace Helbig, Craig Benzine, Rosianna Rojas, the winners of the "Nerd Factor" competition: YouTube users MagicTurtle643 and NerdyAndQuirky. In November, John created a video discussing bullying in general, as well as his personal experience with getting bullied. On September 11, 2015, the Greens began listing all videos on the channel under the Creative Commons Attribution 3.0 license. Hank Green clarified on Reddit that "We didn't mention it, we just switched over. I'm not sure what people would do with a Vlogbrothers video, but I want them to be able to do it."On August 5, 2016, the project "How to Vote in Every State" was launched.
It encourages viewers to register to vote with links to quick, comprehensive videos on how to do so in for each state. In the beginning of 2017, the duo began celebrating their ten years on YouTube. In honor of this
Amsterdam RAI Exhibition and Convention Centre
Amsterdam RAI Exhibition and Convention Centre is a complex of conference and exhibition halls in the Zuidas business district of Amsterdam, Netherlands. Opened in 1961, the RAI welcomed its 75 millionth visitor in February 2001. Up to 2 million people visit the RAI every year; some 50 international conferences and 70 trade shows are held at the RAI annually. The complex consists of 22 conference rooms and 11 halls and has a total floor space of 87,000 m²; the largest hall can seat 12,900 people. The complex includes a musical and concert theatre and underground parking space for over 3,000 cars, it gives its name to the nearby Amsterdam RAI railway station. The origins of the RAI complex can be traced back to 1893, when the trade association RI was founded by a number of bicycle manufacturers; the first bicycle trade show of the RI was held in 1895 at the Paleis voor Volksvlijt building in Amsterdam. In 1900 the RI changed its name to RAI, because many of its members had started manufacturing automobiles in addition to bicycles.
In 1922 the RAI occupied an exhibition hall of its own on the Ferdinand Bolstraat in Amsterdam. This building, the "old RAI", was replaced by the current building complex on Europaplein square, opened by Prince Bernhard of the Netherlands on February 2, 1961; the RAI trade association still owns 75% of the complex, with the remainder in the hands of the municipality of Amsterdam. The RAI completed construction of a 47 metres tall expansion named Elicium in 2009, serving as Europe’s largest conference center. Trade shows and other events held annually at the RAI include: Art Amsterdam, an art fair AutoRAI, an automobile trade show HISWA, a boating and watersports trade show Horecava, a trade fair for the hospitality industry Horti Fair, a trade show for the horticultural industry International Broadcasting Convention, an annual trade show for broadcasters Jumping Amsterdam, an equestrian sporting event LXRY Masters, a trade fair aimed at the wealthiestIn addition, the 1970 Eurovision Song Contest was held at the RAI.
Media related to Amsterdam RAI Exhibition and Convention Centre at Wikimedia Commons Official website RAI, Intertraffic 2007
Video camera tube
Video camera tubes were devices based on the cathode ray tube that were used to capture television images prior to the introduction of charge-coupled devices in the 1980s. Several different types of tubes were in use from the early 1930s to the 1980s. In these tubes, the cathode ray was scanned across an image of the scene to be broadcast; the resultant current was dependent on the brightness of the image on the target. The size of the striking ray was tiny compared to the size of the target, allowing 483 horizontal scan lines per image in the NTSC format, or 576 lines in PAL. Any vacuum tube which operates using a focused beam of electrons, "cathode rays", is known as a cathode ray tube; these are seen as display devices as used in older television receivers and computer displays. The camera pickup tubes described in this article are CRTs, but they display no image. In June 1908, the scientific journal Nature published a letter in which Alan Archibald Campbell-Swinton, fellow of the Royal Society, discussed how a electronic television system could be realized by using cathode ray tubes as both imaging and display devices.
He noted that the "real difficulties lie in devising an efficient transmitter", that it was possible that "no photoelectric phenomenon at present known will provide what is required". A cathode ray tube was demonstrated as a displaying device by the German Professor Max Dieckmann in 1906, his experimental results were published by the journal Scientific American in 1909. Campbell-Swinton expanded on his vision in a presidential address given to the Röntgen Society in November 1911; the photoelectric screen in the proposed transmitting device was a mosaic of isolated rubidium cubes. His concept for a electronic television system was popularized by Hugo Gernsback as the "Campbell-Swinton Electronic Scanning System" in the August 1915 issue of the popular magazine Electrical Experimenter. In a letter to Nature published in October 1926, Campbell-Swinton announced the results of some "not successful experiments" he had conducted with G. M. Minchin and J. C. M. Stanton, they had attempted to generate an electrical signal by projecting an image onto a selenium-coated metal plate, scanned by a cathode ray beam.
These experiments were conducted before March 1914, when Minchin died, but they were repeated by two different teams in 1937, by H. Miller and J. W. Strange from EMI, by H. Iams and A. Rose from RCA. Both teams succeeded in transmitting "very faint" images with the original Campbell-Swinton's selenium-coated plate, but much better images were obtained when the metal plate was covered with zinc sulphide or selenide, or with aluminum or zirconium oxide treated with caesium; these experiments would form the base of the future vidicon. A description of a CRT imaging device appeared in a patent application filed by Edvard-Gustav Schoultz in France in August 1921, published in 1922, although a working device was not demonstrated until some years later. An image dissector is a camera tube that creates an "electron image" of a scene from photocathode emissions which pass through a scanning aperture to an anode, which serves as an electron detector. Among the first to design such a device were German inventors Max Dieckmann and Rudolf Hell, who had titled their 1925 patent application Lichtelektrische Bildzerlegerröhre für Fernseher.
The term may apply to a dissector tube employing magnetic fields to keep the electron image in focus, an element lacking in Dieckmann and Hell's design, in the early dissector tubes built by American inventor Philo Farnsworth. Dieckmann and Hell submitted their application to the German patent office in April 1925, a patent was issued in October 1927, their experiments on the image dissector were announced in the volume 8 of the popular magazine Discovery and in the May 1928 issue of the magazine Popular Radio. However, they never transmitted a well focused image with such a tube. In January 1927, American inventor and television pioneer Philo T. Farnsworth applied for a patent for his Television System that included a device for "the conversion and dissecting of light", its first moving image was transmitted on September 7 of 1927, a patent was issued in 1930. Farnsworth made improvements to the device, among them introducing an electron multiplier made of nickel and deploying a "longitudinal magnetic field" in order to focus the electron image.
The improved device was demonstrated to the press in early September 1928. The introduction of a multipactor in October 1933 and a multi-dynode "electron multiplier" in 1937 made Farnsworth's image dissector the first practical version of a electronic imaging device for television, it had poor light sensitivity, was therefore useful only where illumination was exceptionally high. However, it was ideal for industrial applications, such as monitoring the bright interior of an industrial furnace. Due to their poor light sensitivity, image dissectors were used in television broadcasting, except to scan film and other transparencies. In April 1933, Farnsworth submitted a patent application entitled Image Dissector, but which detailed a CRT-type camera tube; this is among the first patents to propose the use of a "low-velocity" scanning beam and RCA had to buy it in order to sell image orthicon tubes to the general public. However, Farnsworth never transmitted a well focused image with such a tube.
The optical system of the image dissector focuses an image onto a photocathode mounted