Instruct: Given a question, retrieve relevant documents that can help answer the question.
Query: When was television invented?
Once in the U.S., Zworykin found work at the Westinghouse laboratories in Pittsburgh, where he eventually had an opportunity to engage in television experiments. He came up with the main invention of the 20th century – electronic television. He applied for a television patent in the US in 1923. He summarized the resulting invention in two patent applications. The first, entitled "Television Systems", was filed on December 29, 1923, and was followed by a second application in 1925 of essentially the same content, but with minor changes and the addition of a Paget-type screen for color transmission and reception. He was awarded a patent for the 1925 application in 1928, and two patents for the 1923 application that was divided in 1931, although the equipment described was never successfully demonstrated.
The telescope is more a discovery of optical craftsmen than an invention of a scientist. The lens and the properties of refracting and reflecting light had been known since antiquity and theory on how they worked were developed by ancient Greek philosophers, preserved and expanded on in the medieval Islamic world, and had reached a significantly advanced state by the time of the telescope's invention in early modern Europe. But the most significant step cited in the invention of the telescope was the development of lens manufacture for spectacles, first in Venice and Florence in the thirteenth century, and later in the spectacle making centers in both the Netherlands and Germany. It is in the Netherlands in 1608 where the first recorded optical telescopes (refracting telescopes) appeared. The invention is credited to the spectacle makers Hans Lippershey and Zacharias Janssen in Middelburg, and the instrument-maker and optician Jacob Metius of Alkmaar.
Digital television (DTV) is the transmission of television signals, including the sound channel, using digital encoding, in contrast to the earlier television technology, analog television, in which the video and audio are carried by analog signals. It is an innovative advance that represents the first significant evolution in television technology since color television in the 1950s. Digital TV transmits in a new image format called HDTV (high definition television), with greater resolution than analog TV, in a wide screen aspect ratio similar to recent movies in contrast to the narrower screen of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit multiple channels, up to 7, in the same bandwidth occupied by a single channel of analog television, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2006 in some countries, and many industrial countries have now completed the changeover, while other countries are in various stages of adaptation. Different digital television broadcasting standards have been adopted in different parts of the world; below are the more widely used standards:
In 1938, Farnsworth established the Farnsworth Television and Radio Corporation in Fort Wayne, Indiana, with E. A. Nicholas as president and himself as director of research. In September 1939, after a more than decade-long legal battle, RCA finally conceded to a multi-year licensing agreement concerning Farnsworth's 1927 patent for television totaling $1 million. RCA was then free, after showcasing electronic television at New York World's Fair on April 20, 1939, to sell electronic television cameras to the public.
The conventional telephone was invented independently by Alexander Bell and Elisha Gray in 1876. Antonio Meucci invented the first device that allowed the electrical transmission of voice over a line in 1849. However Meucci's device was of little practical value because it relied upon the electrophonic effect and thus required users to place the receiver in their mouth to "hear" what was being said. The first commercial telephone services were set-up in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London.
Eventually communication reached an electronic state, and the telegraph was invented. Harrison Dyar, who sent electrical sparks through chemically treated paper tape to burn dots and dashes, invented the first telegraph in the USA. The telegraph was the first piece of equipment that allowed users to send electronic messages. A more developed version came from Samuel Morse, whose telegraph printed code on tape and was operated using a keypad and an earpiece. The pattern of communication soon became known as Morse code.
The earliest known use of the "Eyewitness News" name in American television was in April 1959 when KYW-TV (now WKYC-TV) – at the time, based in Cleveland and owned by Westinghouse Broadcasting – launched the nation's first 90-minute local newscast (under the title "Eyewitness"), which was combined with the then 15-minute national newscast. The name was then adopted for use by Westinghouse's other television stations – KPIX in San Francisco; WJZ-TV in Baltimore; WBZ-TV in Boston; and KDKA-TV in Pittsburgh – for their local newscasts.
That same year saw the release of the Magnavox Odyssey, the first home video game console which could be connected to a television set. The inventor, Ralph H. Baer, had initially had the idea in 1951 to make an interactive game on a television set. Unable to do so with the technological constraints at the time, he began work on a device that would attach to a television set and display games in 1966, and the "Brown Box", the last prototype of seven, was licensed to Magnavox to adapt and produce. They announced the console in May 1972, and it went on sale that September. The console and its games featured numerous innovations beyond being the first video game device for home consumers: it was the first game to use a raster-scan video display, or television set, directly displayed via modification of a video signal; it was also the first video gaming device to be displayed in a television commercial. It sold for US$100 and shipped with several games, including "Table tennis", which Bushnell had seen a demo of and which "Pong" had been based on. The Odyssey sold over 100,000 units in 1972, and more than 350,000 by the end of 1975, buoyed by the popularity of the table tennis game, in turn driven by the success of "Pong". "Pong" and the Odyssey kicked off a new era of video gaming, with numerous other competitors starting up in the video game industry as it grew in popularity.
Nikola Tesla invented a deceptively simple one-way valve for fluids in 1916, called a Tesla valve. It was patented in 1920 (U.S. patent 1,329,559).
Cable News Network (CNN) is an American news-based pay television channel owned by Turner Broadcasting System, a division of AT&T's WarnerMedia. CNN was founded in 1980 by American media proprietor Ted Turner as a 24-hour cable news channel. Upon its launch, CNN was the first television channel to provide 24-hour news coverage, and was the first all-news television channel in the United States.
The first serious attempt at dedicated television news broadcasts in the United States was by CBS. Upon becoming commercial station WCBW (now WCBS-TV) in 1941, the pioneer New York CBS television station broadcast two daily news programs, at 2:30 and 7:30 p.m. weekdays, anchored by Richard Hubbell. Most of the newscasts featured Hubbell reading a script with only occasional cutaways to a map or still photograph.
After the war, monochrome TV production began in earnest. Color TV was the next major development, and NBC once again won the battle. CBS had their electro-mechanical color television system approved by the FCC on October 10, 1950, but Sarnoff filed an unsuccessful suit in the United States district court to suspend that ruling. Subsequently, he made an appeal to the Supreme Court which eventually upheld the FCC decision. Sarnoff's tenacity and determination to win the "Color War" pushed his engineers to perfect an all-electronic color television system that used a signal that could be received on existing monochrome sets that prevailed. CBS was now unable to take advantage of the color market, due to lack of manufacturing capability and color programming, a system that could not be seen on the millions of black and white receivers and sets that were triple the cost of monochrome sets. A few days after CBS had its color premiere on June 14, 1951, RCA demonstrated a fully functional all-electronic color TV system and became the leading manufacturer of color TV sets in the US.
A transistor radio is a small portable radio receiver that uses transistor-based circuitry. Following their development in 1954, made possible by the invention of the transistor in 1947, they became the most popular electronic communication device in history, with billions manufactured during the 1960s and 1970s. Their pocket size sparked a change in popular music listening habits, allowing people to listen to music anywhere they went. Beginning in the 1980s, however, cheap AM transistor radios were superseded by devices with higher audio quality such as portable CD players, personal audio players, boomboxes, and (eventually) smartphones, some of which contain radios themselves.
In March 1979, the government set up the Ethnic Television Review Panel, which recommended that SBS expand into television. SBS TV began test transmissions in April 1979 when it showed various foreign language programs on ABV-2 Melbourne and ABN-2 Sydney on Sunday mornings. Full-time transmission began at 6:30 pm on 24 October 1980 (United Nations Day), as Channel 0/28. The first program shown was a documentary entitled "Who Are We?", which was hosted by veteran news presenter Peter Luck. At the time, SBS was broadcasting on UHF Channel 28 and VHF Channel 0 (pronounced as "oh" and not "zero"), with a planned discontinuation of the latter at some time in the future. Bruce Gyngell, who introduced television to Australia in 1956, was given the task of introducing the first batch of programs on the new station.
A new Broadcasting Act ("Hōsō Hō") was enacted in 1950, which made NHK a listener-supported independent corporation and simultaneously opened the market for commercial broadcasting in Japan. NHK started television broadcasting in the same year, followed by its Educational TV channel in 1959 and color television broadcasts in 1960.
Refractors were the earliest type of optical telescope. The first practical refracting telescopes appeared in the Netherlands about 1608, and were credited to three individuals, Hans Lippershey and Zacharias Janssen, spectacle-makers in Middelburg, and Jacob Metius of Alkmaar. Galileo Galilei, happening to be in Venice in about the month of May 1609, heard of the invention and constructed a version of his own. Galileo then communicated the details of his invention to the public, and presented the instrument itself to the Doge Leonardo Donato, sitting in full council.
The earliest known telescope appeared in 1608 in the Netherlands when an eyeglass maker named Hans Lippershey tried to obtain a patent on one. Although Lippershey did not receive his patent, news of the new invention soon spread across Europe. The design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. Galileo improved on this design the following year and applied it to astronomy. In 1611, Johannes Kepler described how a far more useful telescope could be made with a convex objective lens and a convex eyepiece lens and by 1655 astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces.
The development of transistors in 1948 by Bell Laboratories led to major improvements to the hearing aid. The transistor was invented by John Bardeen, Walter Brattain, and William Shockley. Transistors were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. These vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement.The 1952 Sonotone 1010 used a transistor stage along with vacuum tubes, to extend battery life. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items, even eyeglasses. In 1951, Raytheon manufactured the transistor and was one of the first companies to mass-produce transistors to throughout America. Raytheon realized that their hearing aid only lasted short-term and began to sell the vacuum-tube hearing aids again along with transistor hearing aids.
The first microphone that enabled proper voice telephony was the (loose-contact) carbon microphone (then called transmitter). This was independently developed around 1878 by David Edward Hughes in England and Emile Berliner and Thomas Edison in the US. Although Edison was awarded the first patent in mid-1877, Hughes had demonstrated his working device in front of many witnesses some years earlier, and most historians credit him with its invention.
The stereoscope was first invented by Sir Charles Wheatstone in 1838. It showed that when two pictures are viewed stereoscopically, they are combined by the brain to produce 3D depth perception. The stereoscope was improved by Louis Jules Duboscq, and a famous picture of Queen Victoria was displayed at The Great Exhibition in 1851. In 1855 the Kinematoscope was invented. In the late 1890s, the British film pioneer William Friese-Greene filed a patent for a 3D movie process. On 10 June 1915, former Edison Studios chief director Edwin S. Porter and William E. Waddell presented tests in red-green anaglyph to an audience at the Astor Theater in New York City and in 1922 the first public 3D movie "The Power of Love" was displayed.
Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor, self-described "Father of Radio", and a pioneer in the development of sound-on-film recording used for motion pictures. He had over 180 patents, but also a tumultuous career—he boasted that he made, then lost, four fortunes. He was also involved in several major patent lawsuits, spent a substantial part of his income on legal bills, and was even tried (and acquitted) for mail fraud. His most famous invention, in 1906, was the three-element "Audion" (triode) vacuum tube, the first practical amplification device. Although De Forest had only a limited understanding of how it worked, it was the foundation of the field of electronics, making possible radio broadcasting, long distance telephone lines, and talking motion pictures, among countless other applications.
The development of television was the result of work by many inventors. Among them, Baird was a prominent pioneer and made major advances in the field. Many historians credit Baird with being the first to produce a live, moving, greyscale television image from reflected light. Baird achieved this, where other inventors had failed, by obtaining a better photoelectric cell and improving the signal conditioning from the photocell and the video amplifier.
Between 1902 and 1907, Arthur Korn invented and built the first successful signal-conditioning circuits for image transmission. The circuits overcame the image-destroying lag effect that is part of selenium photocells. Korn's compensation circuit allowed him to send still fax pictures by telephone or wireless between countries and even over oceans, while his circuit operated without benefit of electronic amplification. Korn's success at transmitting halftone still images suggested that such compensation circuits might work in television. Baird was the direct beneficiary of Korn's research and success.
In his first attempts to develop a working television system, Baird experimented with the Nipkow disk. Paul Gottlieb Nipkow had invented this scanning disc system in 1884. Television historian Albert Abramson calls Nipkow's patent "the master television patent". Nipkow's work is important because Baird and many others chose to develop it into a broadcast medium.
The technology of television has evolved since its early days using a mechanical system invented by Paul Gottlieb Nipkow in 1884. Every television system works on the scanning principle first implemented in the rotating disk scanner of Nipkow. This turns a two-dimensional image into a time series of signals that represent the brightness and color of each resolvable element of the picture. By repeating a two-dimensional image quickly enough, the impression of motion can be transmitted as well. For the receiving apparatus to reconstruct the image, synchronization information is included in the signal to allow proper placement of each line within the image and to identify when a complete image has been transmitted and a new image is to follow.
Television, which first reached the marketplace in the 1940s, attained maturity during the 1950s and by the end of the decade, most American households owned a TV set. A rush to produce larger screens than the tiny ones found on 1940s models occurred during 1950–52. In 1954, RCA intro Bell Telephone Labs produced the first Solar battery. In 1954, you could get a yard of contact paper for only 59 cents. Polypropylene was invented in 1954. In 1955, Jonas Salk invented a polio vaccine which was given to more than seven million American students. In 1956, a solar powered wrist watch was invented.
For its first fifty years the phonograph turntable did not use electronics; the needle and soundhorn were purely mechanical technologies. However, in the 1920s radio broadcasting became the basis of mass production of radio receivers. The vacuum tubes that had made radios practical were used with record players as well, to amplify the sound so that it could be played through a loudspeaker. Television was soon invented, but remained insignificant in the consumer market until the 1950s. The transistor, invented in 1947 by Bell Laboratories, led to significant research in the field of solid-state semiconductors in the early 1950s. The transistor's advantages revolutionized that industry along with other electronics. By 1959 Fairchild Semiconductor had introduced the first planar transistor from which come the origins of Moore's law. Integrated circuits followed when manufacturers built circuits (usually for military purposes) on a single substrate using electrical connections between circuits within the chip itself. Bell's invention of the transistor and the development of semiconductors led to far better and cheaper consumer electronics, such as transistor radios, televisions, and by the 1980s, affordable video game consoles and personal computers that regular middle-class families could buy.