149-646: Geo Television Network is a television channel based in Pakistan . It was established in May 2002 and is owned by the Jang Media Group . The channel began its test transmission on 14 August 2002, with regular transmission beginning on 1 October 2002. Geo Network was founded in May 2002 by Mir Shakil-ur-Rahman . It started out with the launch of its flagship channel Geo News, in October 2002. Hamid Mir joined
298-494: A Red Book CD; thus, the mono source material is usually presented as two identical channels in a standard Red Book stereo track (i.e., mirrored mono ); an MP3 CD , can have audio file formats with mono sound. CD-Text is an extension of the Red Book specification for an audio CD that allows for the storage of additional text information (e.g., album name, song name, artist) on a standards-compliant audio CD. The information
447-458: A patent interference suit against Farnsworth. The U.S. Patent Office examiner disagreed in a 1935 decision, finding priority of invention for Farnsworth against Zworykin. Farnsworth claimed that Zworykin's 1923 system could not produce an electrical image of the type to challenge his patent. Zworykin received a patent in 1928 for a color transmission version of his 1923 patent application. He also divided his original application in 1931. Zworykin
596-437: A personal computer hard disk drive . Several other formats were further derived, both pre-pressed and blank user writable, including write-once audio and data storage ( CD-R ), rewritable media ( CD-RW ), Video CD (VCD), Super Video CD (SVCD), Photo CD , Picture CD , Compact Disc-Interactive ( CD-i ), Enhanced Music CD , and Super Audio CD (SACD) which may have a CD-DA layer. The optophone , first presented in 1931,
745-478: A resolution that is substantially higher. HDTV may be transmitted in different formats: 1080p , 1080i and 720p . Since 2010, with the invention of smart television , Internet television has increased the availability of television programs and movies via the Internet through streaming video services such as Netflix, Amazon Prime Video , iPlayer and Hulu . In 2013, 79% of the world's households owned
894-618: A transistor -based UHF tuner . The first fully transistorized color television in the United States was the Quasar television introduced in 1967. These developments made watching color television a more flexible and convenient proposition. In 1972, sales of color sets finally surpassed sales of black-and-white sets. Color broadcasting in Europe was not standardized on the PAL format until
1043-467: A tuner for receiving and decoding broadcast signals. A visual display device that lacks a tuner is correctly called a video monitor rather than a television. The television broadcasts are mainly a simplex broadcast meaning that the transmitter cannot receive and the receiver cannot transmit. The word television comes from Ancient Greek τῆλε (tele) 'far' and Latin visio 'sight'. The first documented usage of
1192-474: A 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, and cross-interleaved Reed-Solomon coding (CIRC) error correction code —specifications similar to those later settled upon for the standard compact disc format in 1980. Technical details of Sony's digital audio disc were presented during the 62nd AES Convention, held on 13–16 March 1979, in Brussels . Sony's AES technical paper
1341-483: A 1925 demonstration, the image was dim, had low contrast and poor definition, and was stationary. Zworykin's imaging tube never got beyond the laboratory stage. However, RCA, which acquired the Westinghouse patent, asserted that the patent for Farnsworth's 1927 image dissector was written so broadly that it would exclude any other electronic imaging device. Thus, based on Zworykin's 1923 patent application, RCA filed
1490-403: A 2-inch-wide by 2.5-inch-high screen (5 by 6 cm). The large receiver had a screen 24 inches wide by 30 inches high (60 by 75 cm). Both sets could reproduce reasonably accurate, monochromatic, moving images. Along with the pictures, the sets received synchronized sound. The system transmitted images over two paths: first, a copper wire link from Washington to New York City, then
1639-603: A CD. VCDs are playable in dedicated VCD players, most modern DVD-Video players, personal computers, and some video game consoles. The VCD standard was created in 1993 by Sony, Philips, Matsushita , and JVC and is referred to as the White Book standard. Overall picture quality is intended to be comparable to VHS video. Poorly compressed VCD video can sometimes be of lower quality than VHS video, but VCD exhibits block artifacts rather than analog noise and does not deteriorate further with each use. 352×240 (or SIF ) resolution
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#17327839170021788-402: A TV system with a 40-line resolution that employed a CRT display. This was the first working example of a fully electronic television receiver and Takayanagi's team later made improvements to this system parallel to other television developments. Takayanagi did not apply for a patent. In the 1930s, Allen B. DuMont made the first CRTs to last 1,000 hours of use, one of the factors that led to
1937-683: A camera tube, using the CRT instead as a flying-spot scanner to scan slides and film. Ardenne achieved his first transmission of television pictures on 24 December 1933, followed by test runs for a public television service in 1934. The world's first electronically scanned television service then started in Berlin in 1935, the Fernsehsender Paul Nipkow , culminating in the live broadcast of the 1936 Summer Olympic Games from Berlin to public places all over Germany. Philo Farnsworth gave
2086-609: A color television combining a traditional black-and-white display with a rotating colored disk. This device was very "deep" but was later improved with a mirror folding the light path into an entirely practical device resembling a large conventional console. However, Baird was unhappy with the design, and, as early as 1944, had commented to a British government committee that a fully electronic device would be better. In 1939, Hungarian engineer Peter Carl Goldmark introduced an electro-mechanical system while at CBS , which contained an Iconoscope sensor. The CBS field-sequential color system
2235-409: A communal viewing experience to a solitary viewing experience. By 1960, Sony had sold over 4 million portable television sets worldwide. The basic idea of using three monochrome images to produce a color image had been experimented with almost as soon as black-and-white televisions had first been built. Although he gave no practical details, among the earliest published proposals for television
2384-419: A diameter of 120 mm (4.7 in), and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650 MiB ( 681,574,400 bytes) of data. Capacity is routinely extended to 80 minutes and 700 MiB ( 734,003,200 bytes), 90 minutes 800 MiB ( 838,860,800 bytes), or 99 minutes 870 MiB ( 912,261,120 bytes) by arranging data more closely on
2533-479: A diameter of 20 cm (7.9 in) and a sound quality superior to that of the vinyl record. However, due to the unsatisfactory performance of the analog format, two Philips research engineers recommended a digital format in March 1974. In 1977, Philips then established a laboratory with the mission of creating a digital audio disc. The diameter of Philips's prototype compact disc was set at 11.5 cm (4.5 in),
2682-417: A disc played from beginning to end slows its rotation rate during playback. The program area is 86.05 cm and the length of the recordable spiral is 86.05 cm / 1.6 μm = 5.38 km. With a scanning speed of 1.2 m/s, the playing time is 74 minutes or 650 MiB of data on a CD-ROM. A disc with data packed slightly more densely is tolerated by most players (though some old ones fail). Using
2831-764: A fellow of the Royal Society (UK), published a letter in the scientific journal Nature in which he described how "distant electric vision" could be achieved by using a cathode-ray tube, or Braun tube, as both a transmitting and receiving device, he expanded on his vision in a speech given in London in 1911 and reported in The Times and the Journal of the Röntgen Society. In a letter to Nature published in October 1926, Campbell-Swinton also announced
2980-400: A former member of the task force, gives background information on the many technical decisions made, including the choice of the sampling frequency, playing time, and disc diameter. The task force consisted of around 6 persons, though according to Philips, the compact disc was "invented collectively by a large group of people working as a team". Early milestones in the launch and adoption of
3129-469: A graphics signal (typically, the CD+G player is hooked up to a television set or a computer monitor); these graphics are almost exclusively used to display lyrics on a television set for karaoke performers to sing along with. The CD+G format takes advantage of the channels R through W. These six bits store the graphics information. CD + Extended Graphics (CD+EG, also known as CD+XG) is an improved variant of
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#17327839170023278-563: A joint task force of engineers to design a new digital audio disc. Led by engineers Kees Schouhamer Immink and Toshitada Doi , the research pushed forward laser and optical disc technology. After a year of experimentation and discussion, the task force produced the Red Book CD-DA standard. First published in 1980, the standard was formally adopted by the IEC as an international standard in 1987, with various amendments becoming part of
3427-423: A lensed disk scanner with a 48-line resolution. He was granted U.S. Patent No. 1,544,156 (Transmitting Pictures over Wireless) on 30 June 1925 (filed 13 March 1922). Herbert E. Ives and Frank Gray of Bell Telephone Laboratories gave a dramatic demonstration of mechanical television on 7 April 1927. Their reflected-light television system included both small and large viewing screens. The small receiver had
3576-690: A line of the image. Although he never built a working model of the system, variations of Nipkow's spinning-disk " image rasterizer " became exceedingly common. Constantin Perskyi had coined the word television in a paper read to the International Electricity Congress at the International World Fair in Paris on 24 August 1900. Perskyi's paper reviewed the existing electromechanical technologies, mentioning
3725-453: A linear velocity of 1.2 m/s and a narrower track pitch of 1.5 μm increases the playing time to 80 minutes, and data capacity to 700 MiB. Even denser tracks are possible, with semi-standard 90 minute/800 MiB discs having 1.33 μm, and 99 minute/870 MiB having 1.26 μm, but compatibility suffers as density increases. A CD is read by focusing a 780 nm wavelength ( near infrared ) semiconductor laser through
3874-476: A malfunctioning CD writer . Error scanning can reliably predict data losses caused by media deterioration. Support of error scanning differs between vendors and models of optical disc drives , and extended error scanning (known as "advanced error scanning" in Nero DiscSpeed ) has only been available on Plextor and some BenQ optical drives so far, as of 2020. The digital data on a CD begins at
4023-521: A medium" dates from 1927. The term telly is more common in the UK. The slang term "the tube" or the "boob tube" derives from the bulky cathode-ray tube used on most TVs until the advent of flat-screen TVs . Another slang term for the TV is "idiot box." Facsimile transmission systems for still photographs pioneered methods of mechanical scanning of images in the early 19th century. Alexander Bain introduced
4172-557: A new digital audio disc. After a year of experimentation and discussion, the Red Book CD-DA standard was published in 1980. After their commercial release in 1982, compact discs and their players were extremely popular. Despite costing up to $ 1,000, over 400,000 CD players were sold in the United States between 1983 and 1984. By 1988, CD sales in the United States surpassed those of vinyl LPs, and, by 1992, CD sales surpassed those of prerecorded music-cassette tapes. The success of
4321-442: A phosphor plate. The phosphor was patterned so the electrons from the guns only fell on one side of the patterning or the other. Using cyan and magenta phosphors, a reasonable limited-color image could be obtained. He also demonstrated the same system using monochrome signals to produce a 3D image (called " stereoscopic " at the time). A demonstration on 16 August 1944 was the first example of a practical color television system. Work on
4470-471: A production model was halted by the SCAP after World War II . Because only a limited number of holes could be made in the disks, and disks beyond a certain diameter became impractical, image resolution on mechanical television broadcasts was relatively low, ranging from about 30 lines up to 120 or so. Nevertheless, the image quality of 30-line transmissions steadily improved with technical advances, and by 1933
4619-506: A projection screen at London's Dominion Theatre . Mechanically scanned color television was also demonstrated by Bell Laboratories in June 1929 using three complete systems of photoelectric cells , amplifiers, glow-tubes, and color filters, with a series of mirrors to superimpose the red, green, and blue images into one full-color image. The first practical hybrid system was again pioneered by John Logie Baird. In 1940 he publicly demonstrated
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4768-591: A radio link from Whippany, New Jersey . Comparing the two transmission methods, viewers noted no difference in quality. Subjects of the telecast included Secretary of Commerce Herbert Hoover . A flying-spot scanner beam illuminated these subjects. The scanner that produced the beam had a 50-aperture disk. The disc revolved at a rate of 18 frames per second, capturing one frame about every 56 milliseconds . (Today's systems typically transmit 30 or 60 frames per second, or one frame every 33.3 or 16.7 milliseconds, respectively.) Television historian Albert Abramson underscored
4917-616: A resolution that was not surpassed until May 1932 by RCA, with 120 lines. On 25 December 1926, Kenjiro Takayanagi demonstrated a television system with a 40-line resolution that employed a Nipkow disk scanner and CRT display at Hamamatsu Industrial High School in Japan. This prototype is still on display at the Takayanagi Memorial Museum in Shizuoka University , Hamamatsu Campus. His research in creating
5066-641: A signal reportedly to the 60th power or better and showed great promise in all fields of electronics. Unfortunately, an issue with the multipactor was that it wore out at an unsatisfactory rate. At the Berlin Radio Show in August 1931 in Berlin , Manfred von Ardenne gave a public demonstration of a television system using a CRT for both transmission and reception, the first completely electronic television transmission. However, Ardenne had not developed
5215-410: A static photocell. The thallium sulfide (Thalofide) cell, developed by Theodore Case in the U.S., detected the light reflected from the subject and converted it into a proportional electrical signal. This was transmitted by AM radio waves to a receiver unit, where the video signal was applied to a neon light behind a second Nipkow disk rotating synchronized with the first. The brightness of the neon lamp
5364-464: A system that used a mechanical mirror-drum scanner to transmit, in Zworykin's words, "very crude images" over wires to the " Braun tube" ( cathode-ray tube or "CRT") in the receiver. Moving images were not possible because, in the scanner: "the sensitivity was not enough and the selenium cell was very laggy". In 1921, Édouard Belin sent the first image via radio waves with his belinograph . By
5513-521: A television set. The replacement of earlier cathode-ray tube (CRT) screen displays with compact, energy-efficient, flat-panel alternative technologies such as LCDs (both fluorescent-backlit and LED ), OLED displays, and plasma displays was a hardware revolution that began with computer monitors in the late 1990s. Most television sets sold in the 2000s they were still CRT , it was only in early 2010s that flat screen TVs have started to overtake CRT TVs once and for all. Major manufacturers announced
5662-484: A television system using fully electronic scanning and display elements and employing the principle of "charge storage" within the scanning (or "camera") tube. The problem of low sensitivity to light resulting in low electrical output from transmitting or "camera" tubes would be solved with the introduction of charge-storage technology by Kálmán Tihanyi beginning in 1924. His solution was a camera tube that accumulated and stored electrical charges ("photoelectrons") within
5811-460: A variation of this technique called pulse-density modulation (PDM), while Matsushita (now Panasonic ) chose pulse-width modulation (PWM), advertising it as MASH, which is an acronym derived from their patented Multi-stAge noiSe-sHaping PWM topology. The CD was primarily planned as the successor to the vinyl record for playing music, rather than as a data storage medium. However, CDs have grown to encompass other applications. In 1983, following
5960-451: A worm gear is used, a second shorter-throw linear motor, in the form of a coil and magnet, makes fine position adjustments to track eccentricities in the disk at high speed. Some CD drives (particularly those manufactured by Philips during the 1980s and early 1990s) use a swing arm similar to that seen on a gramophone. The pits and lands do not directly represent the 0s and 1s of binary data . Instead, non-return-to-zero, inverted encoding
6109-439: Is an unlawful ban. While on the other hand, countrywide protests were made against Geo for airing controversial content. Television Television ( TV ) is a telecommunication medium for transmitting moving images and sound. Additionally, the term can refer to a physical television set rather than the medium of transmission . Television is a mass medium for advertising, entertainment, news, and sports. The medium
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6258-463: Is capable of more than " radio broadcasting ," which refers to an audio signal sent to radio receivers . Television became available in crude experimental forms in the 1920s, but only after several years of further development was the new technology marketed to consumers. After World War II , an improved form of black-and-white television broadcasting became popular in the United Kingdom and
6407-407: Is debatable whether Russell's concepts, patents, and prototypes instigated and in some measure influenced the compact disc's design. The compact disc is an evolution of LaserDisc technology, where a focused laser beam is used that enables the high information density required for high-quality digital audio signals. Unlike the prior art by Optophonie and James Russell, the information on the disc
6556-506: Is described in a document produced in 1980 by the format's joint creators, Sony and Philips. The document is known colloquially as the Red Book CD-DA after the color of its cover. The format is a two-channel 16-bit PCM encoding at a 44.1 kHz sampling rate per channel. Four-channel sound was to be an allowable option within the Red Book format, but has never been implemented. Monaural audio has no existing standard on
6705-407: Is playable in standard CD players, thus making them backward compatible. CD- MIDI is a format used to store music-performance data, which upon playback is performed by electronic instruments that synthesize the audio. Hence, unlike the original Red Book CD-DA, these recordings are not digitally sampled audio recordings. The CD-MIDI format is defined as an extension of the original Red Book . For
6854-510: Is protected by a film of lacquer normally spin coated directly on the reflective layer. The label is printed on the lacquer layer, usually by screen printing or offset printing . CD data is represented as tiny indentations known as pits , encoded in a spiral track molded into the top of the polycarbonate layer. The areas between pits are known as lands . Each pit is approximately 100 nm deep by 500 nm wide, and varies from 850 nm to 3.5 μm in length. The distance between
7003-522: Is read from a reflective layer using a laser as a light source through a protective substrate. Prototypes were developed by Philips and Sony independently in the late 1970s. Although originally dismissed by Philips Research management as a trivial pursuit, the CD became the primary focus for Philips as the LaserDisc format struggled. In 1979, Sony and Philips set up a joint task force of engineers to design
7152-432: Is stored either in the lead-in area of the CD, where there are roughly five kilobytes of space available or in the subcode channels R to W on the disc, which can store about 31 megabytes. Compact Disc + Graphics is a special audio compact disc that contains graphics data in addition to the audio data on the disc. The disc can be played on a regular audio CD player, but when played on a special CD+G player, it can output
7301-408: Is used: a change from either pit to land or land to pit indicates a 1, while no change indicates a series of 0s. There must be at least two, and no more than ten 0s between each 1, which is defined by the length of the pit. This, in turn, is decoded by reversing the eight-to-fourteen modulation used in mastering the disc, and then reversing the cross-interleaved Reed–Solomon coding , finally revealing
7450-520: The 1939 New York World's Fair . On the other hand, in 1934, Zworykin shared some patent rights with the German licensee company Telefunken. The "image iconoscope" ("Superikonoskop" in Germany) was produced as a result of the collaboration. This tube is essentially identical to the super-Emitron. The production and commercialization of the super-Emitron and image iconoscope in Europe were not affected by
7599-483: The Compact Disc + Graphics (CD+G) format. Like CD+G, CD+EG uses basic CD-ROM features to display text and video information in addition to the music being played. This extra data is stored in subcode channels R-W. Very few CD+EG discs have been published. Super Audio CD (SACD) is a high-resolution, read-only optical audio disc format that was designed to provide higher-fidelity digital audio reproduction than
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#17327839170027748-606: The Compact Disc Digital Audio format which typically provides 74 minutes of audio on a disc. In later years, the compact disc was adapted for non-audio computer data storage purposes as CD-ROM and its derivatives. First released in Japan in October 1982, the CD was the second optical disc technology to be invented, after the much larger LaserDisc (LD). By 2007, 200 billion CDs (including audio CDs, CD-ROMs and CD-Rs) had been sold worldwide. Standard CDs have
7897-748: The EMI engineering team led by Isaac Shoenberg applied in 1932 for a patent for a new device they called "the Emitron", which formed the heart of the cameras they designed for the BBC. On 2 November 1936, a 405-line broadcasting service employing the Emitron began at studios in Alexandra Palace and transmitted from a specially built mast atop one of the Victorian building's towers. It alternated briefly with Baird's mechanical system in adjoining studios but
8046-577: The Pakistan Stock Exchange attack in July 2020, the attackers car was found in the later episode of the channel's show, Deewangi and sparked a reaction from audiences due to the strange coincidence. In May 2014, Geo TV was banned by PEMRA for airing blasphemous content on Geo Entertainment in its morning show Utho Jago Pakistan . Protests were also made in Lahore as people said it
8195-522: The Red Book . Introduced in 1999, it was developed by Sony and Philips, the same companies that created the Red Book . SACD was in a format war with DVD-Audio , but neither has replaced audio CDs. The SACD standard is referred to as the Scarlet Book standard. Titles in the SACD format can be issued as hybrid discs; these discs contain the SACD audio stream as well as a standard audio CD layer which
8344-581: The United Arab Emirates . Its uplink teleport station is Samacom, the uplink provider in the UAE. Geo TV is currently being aired on Paksat 1R . According to Declan Walsh, some militant outfits including Tehrik-i-Taliban Pakistan , Lashkar-e-Jhangvi , and Muttahida Qaumi Movement 's alleged militant wing have infiltrated the Geo group that helped them in executing the murder of Wali Khan Babar and
8493-525: The attack on the Pakistan Navy's aviation base in 2011. On May 10, 2017, an article published by the agency claimed that the number of Afghan refugees living in Pakistan is about 15 million. "Government sources say that more or less 15 million non-registered Afghan refugees are living in Pakistan." This statistic is far from other internationally-accepted values of 2 to 6 million refugees. After
8642-479: The patent war between Zworykin and Farnsworth because Dieckmann and Hell had priority in Germany for the invention of the image dissector, having submitted a patent application for their Lichtelektrische Bildzerlegerröhre für Fernseher ( Photoelectric Image Dissector Tube for Television ) in Germany in 1925, two years before Farnsworth did the same in the United States. The image iconoscope (Superikonoskop) became
8791-752: The vinyl revival . During the 2010s, the increasing popularity of solid-state media and music streaming services caused automakers to remove automotive CD players in favor of minijack auxiliary inputs, wired connections to USB devices and wireless Bluetooth connections. Automakers viewed CD players as using up valuable space and taking up weight which could be reallocated to more popular features, like large touchscreens. By 2021, only Lexus and General Motors were still including CD players as standard equipment with certain vehicles. CDs continued to be strong in some markets such as Japan where 132 million units were produced in 2019. The decline in CD sales has slowed in recent years; in 2021, CD sales increased in
8940-404: The "Iconoscope" by Zworykin, the new tube had a light sensitivity of about 75,000 lux , and thus was claimed to be much more sensitive than Farnsworth's image dissector. However, Farnsworth had overcome his power issues with his Image Dissector through the invention of a completely unique " Multipactor " device that he began work on in 1930, and demonstrated in 1931. This small tube could amplify
9089-665: The 120 mm size was adopted. The adoption of EFM in June 1980 allowed 30 percent more playing time that would have resulted in 97 minutes for 120 mm diameter or 74 minutes for a disc as small as 100 millimetres (3.9 in). Instead, the information density was lowered by 30 percent to keep the playing time at 74 minutes. The 120 mm diameter has been adopted by subsequent formats, including Super Audio CD , DVD , HD DVD , and Blu-ray Disc. The 80-millimetre (3.1 in) diameter discs (" Mini CDs ") can hold up to 24 minutes of music or 210 MiB. The logical format of an audio CD (officially Compact Disc Digital Audio or CD-DA)
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#17327839170029238-661: The 1920s, when amplification made television practical, Scottish inventor John Logie Baird employed the Nipkow disk in his prototype video systems. On 25 March 1925, Baird gave the first public demonstration of televised silhouette images in motion at Selfridges 's department store in London . Since human faces had inadequate contrast to show up on his primitive system, he televised a ventriloquist's dummy named "Stooky Bill," whose painted face had higher contrast, talking and moving. By 26 January 1926, he had demonstrated before members of
9387-421: The 1960s, and broadcasts did not start until 1967. By this point, many of the technical issues in the early sets had been worked out, and the spread of color sets in Europe was fairly rapid. By the mid-1970s, the only stations broadcasting in black-and-white were a few high-numbered UHF stations in small markets and a handful of low-power repeater stations in even smaller markets such as vacation spots. By 1979, even
9536-611: The 2000s designed as successors to the CD: the Super Audio CD (SACD) and DVD-Audio . However neither of these were adopted partly due to increased relevance of digital (virtual) music and the apparent lack of audible improvements in audio quality to most human ears. These effectively extended the CD's longevity in the music market. With the advent and popularity of Internet-based distribution of files in lossy-compressed audio formats such as MP3 , sales of CDs began to decline in
9685-502: The 2000s. For example, between 2000 and 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%. Despite rapidly declining sales year-over-year, the pervasiveness of the technology lingered for a time, with companies placing CDs in pharmacies, supermarkets, and filling station convenience stores to target buyers less likely to be able to use Internet-based distribution. In 2012, CDs and DVDs made up only 34% of music sales in
9834-467: The CD's introduction, Immink and Joseph Braat presented the first experiments with erasable compact discs during the 73rd AES Convention . In June 1985, the computer-readable CD-ROM (read-only memory) and, in 1990, recordable CD-R discs were introduced. Recordable CDs became an alternative to tape for recording and distributing music and could be duplicated without degradation in sound quality. Other newer video formats such as DVD and Blu-ray use
9983-475: The DAC. Even when using high-precision components, this approach was prone to decoding errors. Another issue was jitter , a time-related defect. Confronted with the instability of DACs, manufacturers initially turned to increasing the number of bits in the DAC and using several DACs per audio channel, averaging their output. This increased the cost of CD players but did not solve the core problem. A breakthrough in
10132-679: The Dutch company Philips produced and commercialized the image iconoscope and multicon from 1952 to 1958. U.S. television broadcasting, at the time, consisted of a variety of markets in a wide range of sizes, each competing for programming and dominance with separate technology until deals were made and standards agreed upon in 1941. RCA, for example, used only Iconoscopes in the New York area, but Farnsworth Image Dissectors in Philadelphia and San Francisco. In September 1939, RCA agreed to pay
10281-653: The Farnsworth Television and Radio Corporation royalties over the next ten years for access to Farnsworth's patents. With this historic agreement in place, RCA integrated much of what was best about the Farnsworth Technology into their systems. In 1941, the United States implemented 525-line television. Electrical engineer Benjamin Adler played a prominent role in the development of television. The world's first 625-line television standard
10430-470: The Royal Institution the transmission of an image of a face in motion by radio. This is widely regarded as the world's first true public television demonstration, exhibiting light, shade, and detail. Baird's system used the Nipkow disk for both scanning the image and displaying it. A brightly illuminated subject was placed in front of a spinning Nipkow disk set with lenses that swept images across
10579-560: The Science Museum, South Kensington. In 1928, Baird's company (Baird Television Development Company/Cinema Television) broadcast the first transatlantic television signal between London and New York and the first shore-to-ship transmission. In 1929, he became involved in the first experimental mechanical television service in Germany. In November of the same year, Baird and Bernard Natan of Pathé established France's first television company, Télévision- Baird -Natan. In 1931, he made
10728-465: The Telechrome continued, and plans were made to introduce a three-gun version for full color. However, Baird's untimely death in 1946 ended the development of the Telechrome system. Similar concepts were common through the 1940s and 1950s, differing primarily in the way they re-combined the colors generated by the three guns. The Geer tube was similar to Baird's concept but used small pyramids with
10877-569: The UK broadcasts using the Baird system were remarkably clear. A few systems ranging into the 200-line region also went on the air. Two of these were the 180-line system that Compagnie des Compteurs (CDC) installed in Paris in 1935 and the 180-line system that Peck Television Corp. started in 1935 at station VE9AK in Montreal . The advancement of all-electronic television (including image dissectors and other camera tubes and cathode-ray tubes for
11026-451: The US for the first time since 2004, with Axios citing its rise to "young people who are finding they like hard copies of music in the digital age". It came at the same time as both vinyl and cassette reached sales levels not seen in 30 years. The RIAA reported that CD revenue made a dip in 2022, before increasing again in 2023 and overtook downloading for the first time in over a decade. In
11175-521: The US, 33.4 million CD albums were sold in the year 2022. In France in 2023, 10.5 million CDs were sold, almost double that of vinyl, but both of them represented generated 12% each of the French music industry revenues. Sony and Philips received praise for the development of the compact disc from professional organizations. These awards include: A CD is made from 1.2-millimetre (0.047 in) thick, polycarbonate plastic, and weighs 14–33 grams. From
11324-674: The United States, and television sets became commonplace in homes, businesses, and institutions. During the 1950s, television was the primary medium for influencing public opinion . In the mid-1960s, color broadcasting was introduced in the U.S. and most other developed countries. The availability of various types of archival storage media such as Betamax and VHS tapes, LaserDiscs , high-capacity hard disk drives , CDs , DVDs , flash drives , high-definition HD DVDs and Blu-ray Discs , and cloud digital video recorders has enabled viewers to watch pre-recorded material—such as movies—at home on their own time schedule. For many reasons, especially
11473-572: The United States. By 2015, only 24% of music in the United States was purchased on physical media, two thirds of this consisting of CDs; however, in the same year in Japan, over 80% of music was bought on CDs and other physical formats. In 2018, U.S. CD sales were 52 million units—less than 6% of the peak sales volume in 2000. In the UK, 32 million units were sold, almost 100 million fewer than in 2008. In 2018, Best Buy announced plans to decrease their focus on CD sales, however, while continuing to sell records, sales of which are growing during
11622-461: The analog and channel-separated signals used by analog television . Due to data compression , digital television can support more than one program in the same channel bandwidth. It is an innovative service that represents the most significant evolution in television broadcast technology since color television emerged in the 1950s. Digital television's roots have been tied very closely to the availability of inexpensive, high performance computers . It
11771-406: The bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. Because the pits are indented into the top layer of the disc and are read through the transparent polycarbonate base, the pits form bumps when read. The laser hits the disc, casting a circle of light wider than the modulated spiral track reflecting partially from
11920-451: The center of the disc and proceeds toward the edge, which allows adaptation to the different sizes available. Standard CDs are available in two sizes. By far, the most common is 120 millimetres (4.7 in) in diameter, with a 74-, 80, 90, or 99-minute audio capacity and a 650, 700, 800, or 870 MiB (737,280,000-byte) data capacity. Discs are 1.2 millimetres (0.047 in) thick, with a 15 millimetres (0.59 in) center hole. The size of
12069-407: The center outward, components are: the center spindle hole (15 mm), the first-transition area (clamping ring), the clamping area (stacking ring), the second-transition area (mirror band), the program (data) area, and the rim. The inner program area occupies a radius from 25 to 58 mm. A thin layer of aluminum or, more rarely, gold is applied to the surface, making it reflective. The metal
12218-703: The channel and became one of the first journalists to join Geo News. He started hosting the political talk show, Capital Talk which is the flagship show of Geo News. The first guest at the show was Makhdoom Ameen Faheem with whom Mir discussed the 2002 Pakistan general election . After Geo News became a success, the Geo Network launched a sports channel named Geo Super in late September 2006. Geo Television Network began with Geo TV and has since launched several other Pakistan-based channels, including: Geo TV's broadcast facilities are based at Dubai Media City , in
12367-450: The compact disc has been credited to the cooperation between Philips and Sony, which together agreed upon and developed compatible hardware. The unified design of the compact disc allowed consumers to purchase any disc or player from any company and allowed the CD to dominate the at-home music market unchallenged. In 1974, Lou Ottens, director of the audio division of Philips, started a small group to develop an analog optical audio disc with
12516-462: The convenience of remote retrieval, the storage of television and video programming now also occurs on the cloud (such as the video-on-demand service by Netflix ). At the beginning of the 2010s, digital television transmissions greatly increased in popularity. Another development was the move from standard-definition television (SDTV) ( 576i , with 576 interlaced lines of resolution and 480i ) to high-definition television (HDTV), which provides
12665-498: The design of RCA 's " iconoscope " in 1931, the U.S. patent for Tihanyi's transmitting tube would not be granted until May 1939. The patent for his receiving tube had been granted the previous October. Both patents had been purchased by RCA prior to their approval. Charge storage remains a basic principle in the design of imaging devices for television to the present day. On 25 December 1926, at Hamamatsu Industrial High School in Japan, Japanese inventor Kenjiro Takayanagi demonstrated
12814-525: The development of HDTV technology, the MUSE analog format proposed by NHK , a Japanese company, was seen as a pacesetter that threatened to eclipse U.S. electronics companies' technologies. Until June 1990, the Japanese MUSE standard, based on an analog system, was the front-runner among the more than 23 other technical concepts under consideration. Then, a U.S. company, General Instrument, demonstrated
12963-423: The diagonal of an audio cassette. Heitaro Nakajima , who developed an early digital audio recorder within Japan's national public broadcasting organization, NHK , in 1970, became general manager of Sony's audio department in 1971. In 1973, his team developed a digital PCM adaptor that made audio recordings using a Betamax video recorder. After this, in 1974 the leap to storing digital audio on an optical disc
13112-535: The discontinuation of CRT, Digital Light Processing (DLP), plasma, and even fluorescent-backlit LCDs by the mid-2010s. LEDs are being gradually replaced by OLEDs. Also, major manufacturers have started increasingly producing smart TVs in the mid-2010s. Smart TVs with integrated Internet and Web 2.0 functions became the dominant form of television by the late 2010s. Television signals were initially distributed only as terrestrial television using high-powered radio-frequency television transmitters to broadcast
13261-406: The entire market share in regard to US music sales . The CD is considered the last dominant audio format of the album era , as the rise of MP3 , iTunes , cellular ringtones , and other downloadable music formats in the mid-2000s ended the decade-long dominance of the CD. The format was later adapted (as CD-ROM ) for general purpose data storage and initially could hold much more data than
13410-421: The extra information in the signal and produce a limited-resolution color display. The higher-resolution black-and-white and lower-resolution color images combine in the brain to produce a seemingly high-resolution color image. The NTSC standard represented a significant technical achievement. The first color broadcast (the first episode of the live program The Marriage ) occurred on 8 July 1954. However, during
13559-472: The facsimile machine between 1843 and 1846. Frederick Bakewell demonstrated a working laboratory version in 1851. Willoughby Smith discovered the photoconductivity of the element selenium in 1873. As a 23-year-old German university student, Paul Julius Gottlieb Nipkow proposed and patented the Nipkow disk in 1884 in Berlin . This was a spinning disk with a spiral pattern of holes, so each hole scanned
13708-516: The first few years of its existence, the CD was a medium used purely for audio. In 1988, the Yellow Book CD-ROM standard was established by Sony and Philips, which defined a non-volatile optical data computer data storage medium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive. Video CD (VCD, View CD, and Compact Disc digital video) is a standard digital format for storing video media on
13857-463: The first four UK albums by the Beatles were released in mono on compact disc. The growing acceptance of the CD in 1983 marks the beginning of the popular digital audio revolution. It was enthusiastically received, especially in the early-adopting classical music and audiophile communities, and its handling quality received particular praise. As the price of players gradually came down, and with
14006-440: The first outdoor remote broadcast of The Derby . In 1932, he demonstrated ultra-short wave television. Baird's mechanical system reached a peak of 240 lines of resolution on BBC telecasts in 1936, though the mechanical system did not scan the televised scene directly. Instead, a 17.5 mm film was shot, rapidly developed, and then scanned while the film was still wet. A U.S. inventor, Charles Francis Jenkins , also pioneered
14155-431: The following ten years, most network broadcasts and nearly all local programming continued to be black-and-white. It was not until the mid-1960s that color sets started selling in large numbers, due in part to the color transition of 1965, in which it was announced that over half of all network prime-time programming would be broadcast in color that fall. The first all-color prime-time season came just one year later. In 1972,
14304-813: The format included: The first artist to sell a million copies on CD was Dire Straits , with their 1985 album Brothers in Arms . One of the first CD markets was devoted to reissuing popular music whose commercial potential was already proven. The first major artist to have their entire catalog converted to CD was David Bowie , whose first fourteen studio albums (up to Scary Monsters (and Super Creeps) ) of (then) sixteen were made available by RCA Records in February 1985, along with four greatest hits albums; his fifteenth and sixteenth albums ( Let's Dance and Tonight , respectively) had already been issued on CD by EMI Records in 1983 and 1984, respectively. On 26 February 1987,
14453-530: The hole was chosen by Joop Sinjou and based on a Dutch 10-cent coin: a dubbeltje . Philips/Sony patented the physical dimensions. The official Philips history says the capacity was specified by Sony executive Norio Ohga to be able to contain the entirety of Beethoven's Ninth Symphony on one disc. This is a myth according to Kees Immink , as the EFM code format had not yet been decided in December 1979, when
14602-417: The iconoscope (or Emitron) produced an electronic signal and concluded that its real efficiency was only about 5% of the theoretical maximum. They solved this problem by developing and patenting in 1934 two new camera tubes dubbed super-Emitron and CPS Emitron . The super-Emitron was between ten and fifteen times more sensitive than the original Emitron and iconoscope tubes, and, in some cases, this ratio
14751-693: The industrial standard for public broadcasting in Europe from 1936 until 1960, when it was replaced by the vidicon and plumbicon tubes. Indeed, it represented the European tradition in electronic tubes competing against the American tradition represented by the image orthicon. The German company Heimann produced the Superikonoskop for the 1936 Berlin Olympic Games, later Heimann also produced and commercialized it from 1940 to 1955; finally
14900-505: The introduction of the portable Discman , the CD began to gain popularity in the larger popular and rock music markets. With the rise in CD sales, pre-recorded cassette tape sales began to decline in the late 1980s; CD sales overtook cassette sales in the early 1990s. In 1988, 400 million CDs were manufactured by 50 pressing plants around the world. Early CD players employed binary-weighted digital-to-analog converters (DAC), which contained individual electrical components for each bit of
15049-437: The invention of the first working transistor at Bell Labs , Sony founder Masaru Ibuka predicted in 1952 that the transition to electronic circuits made of transistors would lead to smaller and more portable television sets. The first fully transistorized, portable solid-state television set was the 8-inch Sony TV8-301 , developed in 1959 and released in 1960. This began the transformation of television viewership from
15198-476: The label side of the disc. Scratches on the clear side can be repaired by refilling them with similar refractive plastic or by careful polishing. The edges of CDs are sometimes incompletely sealed, allowing gases and liquids to enter the CD and corrode the metal reflective layer and/or interfere with the focus of the laser on the pits, a condition known as disc rot . The fungus Geotrichum candidum has been found—under conditions of high heat and humidity—to consume
15347-510: The lands and partially from the top of any bumps where they are present. As the laser passes over a pit (bump), its height means that the round trip path of the light reflected from its peak is 1/2 wavelength out of phase with the light reflected from the land around it. This is because the height of a bump is around 1/4 of the wavelength of the light used, so the light falls 1/4 out of phase before reflection and another 1/4 wavelength out of phase after reflection. This causes partial cancellation of
15496-419: The laser's reflection from the surface. By measuring the reflected intensity change with a photodiode , a modulated signal is read back from the disc. To accommodate the spiral pattern of data, the laser is placed on a mobile mechanism within the disc tray of any CD player. This mechanism typically takes the form of a sled that moves along a rail. The sled can be driven by a worm gear or linear motor . Where
15645-401: The last holdout among daytime network programs converted to color, resulting in the first completely all-color network season. Early color sets were either floor-standing console models or tabletop versions nearly as bulky and heavy, so in practice they remained firmly anchored in one place. GE 's relatively compact and lightweight Porta-Color set was introduced in the spring of 1966. It used
15794-464: The last of these had converted to color. By the early 1980s, B&W sets had been pushed into niche markets, notably low-power uses, small portable sets, or for use as video monitor screens in lower-cost consumer equipment. By the late 1980s, even these last holdout niche B&W environments had inevitably shifted to color sets. Digital television (DTV) is the transmission of audio and video by digitally processed and multiplexed signals, in contrast to
15943-428: The late 1980s culminated in development of the 1-bit DAC , which converts high-resolution low-frequency digital input signal into a lower-resolution high-frequency signal that is mapped to voltages and then smoothed with an analog filter. The temporary use of a lower-resolution signal simplified circuit design and improved efficiency, which is why it became dominant in CD players starting from the early 1990s. Philips used
16092-466: The original Campbell-Swinton's selenium-coated plate. Although others had experimented with using a cathode-ray tube as a receiver, the concept of using one as a transmitter was novel. The first cathode-ray tube to use a hot cathode was developed by John B. Johnson (who gave his name to the term Johnson noise ) and Harry Weiner Weinhart of Western Electric , and became a commercial product in 1922. In 1926, Hungarian engineer Kálmán Tihanyi designed
16241-456: The phosphors deposited on their outside faces instead of Baird's 3D patterning on a flat surface. The Penetron used three layers of phosphor on top of each other and increased the power of the beam to reach the upper layers when drawing those colors. The Chromatron used a set of focusing wires to select the colored phosphors arranged in vertical stripes on the tube. One of the great technical challenges of introducing color broadcast television
16390-536: The polycarbonate plastic and aluminium found in CDs. The data integrity of compact discs can be measured using surface error scanning , which can measure the rates of different types of data errors, known as C1 , C2 , CU and extended (finer-grain) error measurements known as E11 , E12 , E21 , E22 , E31 and E32 , of which higher rates indicate a possibly damaged or unclean data surface, low media quality, deteriorating media and recordable media written to by
16539-463: The possibility of a digital television signal. This breakthrough was of such significance that the FCC was persuaded to delay its decision on an ATV standard until a digitally-based standard could be developed. Compact disc The compact disc ( CD ) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. It uses
16688-507: The public at this time, viewing of the color field tests was restricted to RCA and CBS engineers and the invited press. The War Production Board halted the manufacture of television and radio equipment for civilian use from 22 April 1942 to 20 August 1945, limiting any opportunity to introduce color television to the general public. As early as 1940, Baird had started work on a fully electronic system he called Telechrome . Early Telechrome devices used two electron guns aimed at either side of
16837-543: The raw data stored on the disc. These encoding techniques (defined in the Red Book ) were originally designed for CD Digital Audio , but they later became a standard for almost all CD formats (such as CD-ROM ). CDs are susceptible to damage during handling and from environmental exposure. Pits are much closer to the label side of a disc, enabling defects and contaminants on the clear side to be out of focus during playback. Consequently, CDs are more likely to suffer damage on
16986-512: The receiver, a type of Kerr cell modulated the light, and a series of differently angled mirrors attached to the edge of a rotating disc scanned the modulated beam onto the display screen. A separate circuit regulated synchronization. The 8x8 pixel resolution in this proof-of-concept demonstration was just sufficient to clearly transmit individual letters of the alphabet. An updated image was transmitted "several times" each second. In 1911, Boris Rosing and his student Vladimir Zworykin created
17135-415: The reproducer) marked the start of the end for mechanical systems as the dominant form of television. Mechanical television, despite its inferior image quality and generally smaller picture, would remain the primary television technology until the 1930s. The last mechanical telecasts ended in 1939 at stations run by a lot of public universities in the United States. In 1897, English physicist J. J. Thomson
17284-564: The resolution of the color information to conserve bandwidth. As black-and-white televisions could receive the same transmission and display it in black-and-white, the color system adopted is [backwards] "compatible." ("Compatible Color," featured in RCA advertisements of the period, is mentioned in the song " America ," of West Side Story , 1957.) The brightness image remained compatible with existing black-and-white television sets at slightly reduced resolution. In contrast, color televisions could decode
17433-558: The results of some "not very 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 that was simultaneously scanned by a cathode ray beam. These experiments were conducted before March 1914, when Minchin died, but they were later repeated by two different teams in 1937, by H. Miller and J. W. Strange from EMI , and by H. Iams and A. Rose from RCA . Both teams successfully transmitted "very faint" images with
17582-432: The same physical geometry as CD, and most DVD and Blu-ray players are backward compatible with audio CDs. CD sales in the United States peaked by 2000. By the early 2000s, the CD player had largely replaced the audio cassette player as standard equipment in new automobiles, with 2010 being the final model year for any car in the United States to have a factory-equipped cassette player. Two new formats were marketed in
17731-488: The same-sized disc. The Mini CD has various diameters ranging from 60 to 80 millimetres (2.4 to 3.1 in); they have been used for CD singles or delivering device drivers . The CD gained rapid popularity in the 1990s, quickly outselling all other audio formats in the United States by 1991, ending the market dominance of the phonograph record and the cassette tape . By 2000, the CD accounted for 92.3% of
17880-449: The signal to individual television receivers. Alternatively, television signals are distributed by coaxial cable or optical fiber , satellite systems, and, since the 2000s, via the Internet. Until the early 2000s, these were transmitted as analog signals, but a transition to digital television was expected to be completed worldwide by the late 2010s. A standard television set consists of multiple internal electronic circuits , including
18029-595: The significance of the Bell Labs demonstration: "It was, in fact, the best demonstration of a mechanical television system ever made to this time. It would be several years before any other system could even begin to compare with it in picture quality." In 1928, WRGB , then W2XB, was started as the world's first television station. It broadcast from the General Electric facility in Schenectady, NY . It
18178-647: The spectrum of colors at the transmitting end and could not have worked as he described it. Another inventor, Hovannes Adamian , also experimented with color television as early as 1907. The first color television project is claimed by him, and was patented in Germany on 31 March 1908, patent No. 197183, then in Britain, on 1 April 1908, patent No. 7219, in France (patent No. 390326) and in Russia in 1910 (patent No. 17912). Scottish inventor John Logie Baird demonstrated
18327-511: The standard in 1996. Philips coined the term compact disc in line with another audio product, the Compact Cassette , and contributed the general manufacturing process , based on video LaserDisc technology. Philips also contributed eight-to-fourteen modulation (EFM), while Sony contributed the error-correction method, CIRC, which offers resilience to defects such as scratches and fingerprints. The Compact Disc Story , told by
18476-546: The system was improved further by eliminating a motor generator so that his television system had no mechanical parts. That year, Farnsworth transmitted the first live human images with his system, including a three and a half-inch image of his wife Elma ("Pem") with her eyes closed (possibly due to the bright lighting required). Meanwhile, Vladimir Zworykin also experimented with the cathode-ray tube to create and show images. While working for Westinghouse Electric in 1923, he began to develop an electronic camera tube. However, in
18625-585: The television. He published an article on "Motion Pictures by Wireless" in 1913, transmitted moving silhouette images for witnesses in December 1923, and on 13 June 1925, publicly demonstrated synchronized transmission of silhouette pictures. In 1925, Jenkins used the Nipkow disk and transmitted the silhouette image of a toy windmill in motion over a distance of 5 miles (8 km), from a naval radio station in Maryland to his laboratory in Washington, D.C., using
18774-493: The term dates back to 1900, when the Russian scientist Constantin Perskyi used it in a paper that he presented in French at the first International Congress of Electricity, which ran from 18 to 25 August 1900 during the International World Fair in Paris. The anglicized version of the term is first attested in 1907, when it was still "...a theoretical system to transmit moving images over telegraph or telephone wires ". It
18923-525: The tube throughout each scanning cycle. The device was first described in a patent application he filed in Hungary in March 1926 for a television system he called "Radioskop". After further refinements included in a 1928 patent application, Tihanyi's patent was declared void in Great Britain in 1930, so he applied for patents in the United States. Although his breakthrough would be incorporated into
19072-522: The use of a CRT as a display device. The Braun tube became the foundation of 20th century television. In 1906 the Germans Max Dieckmann and Gustav Glage produced raster images for the first time in a CRT. In 1907, Russian scientist Boris Rosing used a CRT in the receiving end of an experimental video signal to form a picture. He managed to display simple geometric shapes onto the screen. In 1908, Alan Archibald Campbell-Swinton ,
19221-494: The widespread adoption of television. On 7 September 1927, U.S. inventor Philo Farnsworth 's image dissector camera tube transmitted its first image, a simple straight line, at his laboratory at 202 Green Street in San Francisco. By 3 September 1928, Farnsworth had developed the system sufficiently to hold a demonstration for the press. This is widely regarded as the first electronic television demonstration. In 1929,
19370-420: The windings (the pitch ) is 1.6 μm (measured center-to-center, not between the edges). When playing an audio CD, a motor within the CD player spins the disc to a scanning velocity of 1.2–1.4 m/s ( constant linear velocity , CLV)—equivalent to approximately 500 RPM at the inside of the disc, and approximately 200 RPM at the outside edge. The track on the CD begins at the inside and spirals outward so
19519-430: The work of Nipkow and others. However, it was not until 1907 that developments in amplification tube technology by Lee de Forest and Arthur Korn , among others, made the design practical. The first demonstration of the live transmission of images was by Georges Rignoux and A. Fournier in Paris in 1909. A matrix of 64 selenium cells, individually wired to a mechanical commutator , served as an electronic retina . In
19668-457: The world's first color transmission on 3 July 1928, using scanning discs at the transmitting and receiving ends with three spirals of apertures, each spiral with filters of a different primary color, and three light sources at the receiving end, with a commutator to alternate their illumination. Baird also made the world's first color broadcast on 4 February 1938, sending a mechanically scanned 120-line image from Baird's Crystal Palace studios to
19817-549: The world's first public demonstration of an all-electronic television system, using a live camera, at the Franklin Institute of Philadelphia on 25 August 1934 and for ten days afterward. Mexican inventor Guillermo González Camarena also played an important role in early television. His experiments with television (known as telectroescopía at first) began in 1931 and led to a patent for the "trichromatic field sequential system" color television in 1940. In Britain,
19966-463: Was "...formed in English or borrowed from French télévision ." In the 19th century and early 20th century, other "...proposals for the name of a then-hypothetical technology for sending pictures over distance were telephote (1880) and televista (1904)." The abbreviation TV is from 1948. The use of the term to mean "a television set " dates from 1941. The use of the term to mean "television as
20115-459: Was able, in his three well-known experiments, to deflect cathode rays, a fundamental function of the modern cathode-ray tube (CRT). The earliest version of the CRT was invented by the German physicist Ferdinand Braun in 1897 and is also known as the "Braun" tube. It was a cold-cathode diode , a modification of the Crookes tube , with a phosphor -coated screen. Braun was the first to conceive
20264-468: Was an early device that used light for both recording and playback of sound signals on a transparent photograph . More than thirty years later, American inventor James T. Russell has been credited with inventing the first system to record digital media on a photosensitive plate. Russell's patent application was filed in 1966, and he was granted a patent in 1970. Following litigation, Sony and Philips licensed Russell's patents for recording in 1988. It
20413-518: Was considerably greater. It was used for outside broadcasting by the BBC, for the first time, on Armistice Day 1937, when the general public could watch on a television set as the King laid a wreath at the Cenotaph. This was the first time that anyone had broadcast a live street scene from cameras installed on the roof of neighboring buildings because neither Farnsworth nor RCA would do the same until
20562-654: Was designed in the Soviet Union in 1944 and became a national standard in 1946. The first broadcast in 625-line standard occurred in Moscow in 1948. The concept of 625 lines per frame was subsequently implemented in the European CCIR standard. In 1936, Kálmán Tihanyi described the principle of plasma display , the first flat-panel display system. Early electronic television sets were large and bulky, with analog circuits made of vacuum tubes . Following
20711-464: Was easily made. Sony first publicly demonstrated an optical digital audio disc in September 1976. A year later, in September 1977, Sony showed the press a 30 cm (12 in) disc that could play an hour of digital audio (44,100 Hz sampling rate and 16-bit resolution) using modified frequency modulation encoding. In September 1978, the company demonstrated an optical digital audio disc with
20860-411: Was more reliable and visibly superior. This was the world's first regular "high-definition" television service. The original U.S. iconoscope was noisy, had a high ratio of interference to signal, and ultimately gave disappointing results, especially compared to the high-definition mechanical scanning systems that became available. The EMI team, under the supervision of Isaac Shoenberg , analyzed how
21009-408: Was not until the 1990s that digital television became possible. Digital television was previously not practically possible due to the impractically high bandwidth requirements of uncompressed digital video , requiring around 200 Mbit/s for a standard-definition television (SDTV) signal, and over 1 Gbit/s for high-definition television (HDTV). A digital television service
21158-410: Was one by Maurice Le Blanc in 1880 for a color system, including the first mentions in television literature of line and frame scanning. Polish inventor Jan Szczepanik patented a color television system in 1897, using a selenium photoelectric cell at the transmitter and an electromagnet controlling an oscillating mirror and a moving prism at the receiver. But his system contained no means of analyzing
21307-855: Was partly mechanical, with a disc made of red, blue, and green filters spinning inside the television camera at 1,200 rpm and a similar disc spinning in synchronization in front of the cathode-ray tube inside the receiver set. The system was first demonstrated to the Federal Communications Commission (FCC) on 29 August 1940 and shown to the press on 4 September. CBS began experimental color field tests using film as early as 28 August 1940 and live cameras by 12 November. NBC (owned by RCA) made its first field test of color television on 20 February 1941. CBS began daily color field tests on 1 June 1941. These color systems were not compatible with existing black-and-white television sets , and, as no color television sets were available to
21456-524: Was popularly known as " WGY Television." Meanwhile, in the Soviet Union , Leon Theremin had been developing a mirror drum-based television, starting with 16 lines resolution in 1925, then 32 lines, and eventually 64 using interlacing in 1926. As part of his thesis, on 7 May 1926, he electrically transmitted and then projected near-simultaneous moving images on a 5-square-foot (0.46 m ) screen. By 1927 Theremin had achieved an image of 100 lines,
21605-517: Was proposed in 1986 by Nippon Telegraph and Telephone (NTT) and the Ministry of Posts and Telecommunication (MPT) in Japan, where there were plans to develop an "Integrated Network System" service. However, it was not possible to implement such a digital television service practically until the adoption of DCT video compression technology made it possible in the early 1990s. In the mid-1980s, as Japanese consumer electronics firms forged ahead with
21754-514: Was published on 1 March 1979. A week later, on 8 March, Philips publicly demonstrated a prototype of an optical digital audio disc at a press conference called "Philips Introduce Compact Disc" in Eindhoven , Netherlands. Sony executive Norio Ohga , later CEO and chairman of Sony, and Heitaro Nakajima were convinced of the format's commercial potential and pushed further development despite widespread skepticism. In 1979, Sony and Philips set up
21903-515: Was the desire to conserve bandwidth , potentially three times that of the existing black-and-white standards, and not use an excessive amount of radio spectrum . In the United States, after considerable research, the National Television Systems Committee approved an all-electronic system developed by RCA , which encoded the color information separately from the brightness information and significantly reduced
22052-500: Was unable or unwilling to introduce evidence of a working model of his tube that was based on his 1923 patent application. In September 1939, after losing an appeal in the courts and being determined to go forward with the commercial manufacturing of television equipment, RCA agreed to pay Farnsworth US$ 1 million over ten years, in addition to license payments, to use his patents. In 1933, RCA introduced an improved camera tube that relied on Tihanyi's charge storage principle. Called
22201-419: Was varied in proportion to the brightness of each spot on the image. As each hole in the disk passed by, one scan line of the image was reproduced. Baird's disk had 30 holes, producing an image with only 30 scan lines, just enough to recognize a human face. In 1927, Baird transmitted a signal over 438 miles (705 km) of telephone line between London and Glasgow . Baird's original 'televisor' now resides in
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