History of videotelephony
The videophone as a concept began to materialize shortly after the telephone was patented in 1876, and its history is closely connected to that of the telephone. Many attempts were made to create a practial video-telephone, and were met with repeated commercial failure because of high cost, lack of popular demand and a failure to reach the threshold for the network effect to apply.
Videotelephony finally reached the mainstream in the 2000s with the subsumption of videotelephony into modern multifunction smartphones and videoconferencing apps which have made videotelephony ubiquitous at the same time as eliminating the videophone as a distinct product category.
Early history
Barely two years after the telephone was first patented in the United States in 1876 by Alexander Graham Bell, an early concept of a combined videophone and wide-screen television called a telephonoscope was conceptualized in the popular periodicals of the day. It was also mentioned in various early science fiction works such as Le Vingtième siècle. La vie électrique and other works written by Albert Robida, and was also sketched in various cartoons by George du Maurier as a fictional invention of Thomas Edison. One such sketch was published on December 9, 1878, in Punch magazine.The term "telectroscope" was also used in 1878 by French writer and publisher Louis Figuier, to popularize an invention wrongly interpreted as real and incorrectly ascribed to Dr. Bell, possibly after his Volta Laboratory discreetly deposited a sealed container of a Graphophone phonograph at the Smithsonian Institution for safekeeping. Written under the pseudonym "Electrician", one article earlier claimed that "an eminent scientist" had invented a device whereby objects or people anywhere in the world "....could be seen anywhere by anybody". The device, among other functions, would allow merchants to transmit pictures of their wares to their customers, and the contents of museum collections to be made available to scholars in distant cities...." In the era prior to the advent of broadcasting, electrical "seeing" devices were conceived as adjuncts to the telephone, thus creating the concept of a videophone.
Fraudulent reports of "amazing" advances in video telephones would be publicized as early as 1880 and would reoccur every few years, such as the episode of "Dr. Sylvestre" of Paris who claimed in 1902 to have invented a powerful video telephone, termed a "spectograph", the intellectual property rights he believed were worth $5,000,000. After reviewing his claim Dr. Bell denounced the supposed invention as a "fairy tale", and publicly commented on the charlatans promoting bogus inventions for financial gain or self-promotion.
However Dr. Alexander Graham Bell personally thought that videotelephony was achievable even though his contributions to its advancement were incidental. In April 1891, Dr. Bell actually did record conceptual notes on an "electrical radiophone", which discussed the possibility of "seeing by electricity" using devices that employed tellurium or selenium imaging components. Bell wrote, decades prior to the invention of the image dissector:
Bell went on to later predict that: "...the day would come when the man at the telephone would be able to see the distant person to whom he was speaking." The discoveries in physics, chemistry and materials science underlying video technology would not be in place until the mid-1920s, first being utilized in electromechanical television. More practical "all-electronic" video and television would not emerge until 1939, but would then suffer several more years of delays before gaining popularity due to the onset and effects of World War II.
The compound term "videophone" slowly entered into general usage after 1950, although "video telephone" likely entered the lexicon earlier after video was coined in 1935. Prior to that time there appeared to be no standard terms for "video telephone", with expressions such as "sight-sound television system", "visual radio" and nearly 20 others being used to describe the marriage of telegraph, telephone, television and radio technologies employed in early experiments.
Among the technological precursors to the videophone were telegraphic image transmitters created by several companies, such as the wirephoto used by Western Union, and the teleostereograph developed by AT&T's Bell Labs, which were forerunners of today's fax machines. Such early image transmitters were themselves based on previous work by Ernest Hummel and others in the 19th century. By 1927 AT&T had created its earliest electromechanical television-videophone called the ikonophone, which operated at 18 frames per second and occupied half a room full of equipment cabinets. An early U.S. test in 1927 had their then-Commerce Secretary Herbert Hoover address an audience in New York City from Washington, D.C.; although the audio portion was two-way, the video portion was one-way with only those in New York being able to see Hoover.
By 1930, AT&T's "two-way television-telephone" system was in full-scale experimental use. The Bell Labs' Manhattan facility devoted years of research to it during the 1930s, led by Dr. Herbert Ives along with his team of more than 200 scientists, engineers and technicians, intending to develop it for both telecommunication and broadcast entertainment purposes.
There were also other public demonstrations of "two-way television-telephone" systems during this period by inventors and entrepreneurs who sought to compete with AT&T, although none appeared capable of dealing with the technical issues of signal compression that Bell Labs would eventually resolve. Signal compression, and its later sibling data compression were fundamental to the issue of transmitting the very large bandwidth of low-resolution black and white video through the very limited capacity of low-speed copper PSTN telephone lines. After the Second World War, Bell Labs resumed its efforts during the 1950s and 1960s, eventually leading to AT&T's Picturephone.
Closed-circuit videophone systems: 1936–1940
In early 1936, the first public video telephone service, Nazi Germany's Gegensehn-Fernsprechanlagen, was developed by Dr. Georg Schubert, who headed the development department at the Fernseh-AG, a technical combine for television broadcasting technology. Two closed-circuit televisions were installed in the German Reichspost in Berlin and Leipzig and connected together via a dedicated broadband coaxial cable to cover the distance of approximately 160 km. The system's opening was inaugurated by the Minister of Posts Paul von Eltz-Rübenach in Berlin on March 1, 1936, who viewed and spoke with Leipzig's chief burgomaster.Schubert's system was based on Gunter Krawinkel's earlier research of the late-1920s that he displayed at the 1929 Internationale Funkausstellung Berlin. Schubet's higher-performance system employed a Nipkow disk flying-spot scanner for its transmitter and a 20 cm cathode-ray display tube with a resolution of 150 lines running at 25 frames per second.
After a period of experimentation, the system entered public use and was soon extended with another 160 km of coaxial cable from Berlin to Hamburg, and then in July 1938 from Leipzig to Nuremberg and Munich. Point-to-point video calling required swapping connections on a telephone switchboard. The system eventually operated with more than 1,000 km of coaxial cable transmission lines. The videophones were integrated within large public videophone booths, with two booths provided per city. Calls between Berlin and Leipzig cost RM3½, approximately one sixth of a British pound sterling, or about one-fifteenth of the average weekly wage.
The video telephone equipment used in Berlin was designed and built by the German Post Office Laboratory. Videophone equipment used in other German cities were developed by Fernseh A.G., partly owned by Baird Television Ltd. of the U.K., inventors of the world's first functional television. During its life the German system underwent further development and testing, resulting in higher resolutions and a conversion to an all-electronic camera tube transmission system to replace its mechanical Nipkow scanning disc. While the system's image quality was primitive by modern standards, it was deemed impressive in contemporary reports of the era, with users able to clearly discern the hands on wristwatches.
The videophones were offered to the general public, which had to visit special post office Fernsehsprechstellen simultaneously in their respective cities, but which at the same time also had Nazi political and propagandistic overtones similar to the broadcasting of the 1936 Olympic Games in Berlin. The German post office announced ambitious plans to extend their public videophone network to Cologne, Frankfurt and Vienna, Austria, but expansion plans were discontinued in 1939 with the start of the Second World War. After Germany subsequently became fully engaged in the war its public videophone system was closed in 1940, with its expensive inter-city broadband cables converted to telegraphic message traffic and broadcast television service.
A similar commercial post office system was also created in France during the late-1930s. The Deutsche Bundespost postal service would decades later develop and deploy its BIGFON videotelephony network from 1981 to 1988, serving several large German cities, and also created one of Europe's first public switched broadband services in 1989.
AT&T Picturephone Mod I: 1964–1970
In the United States, AT&T's Bell Labs conducted extensive research and development of videophones, eventually leading to public demonstrations of its trademarked "Picturephone" product in the 1960s. Its large Manhattan experimental laboratory devoted years of technical research during the 1930s, led by Dr. Herbert Ives along with his team of more than 200 scientists, engineers and technicians. The Bell Labs early experimental model of 1930 had transmitted uncompressed video through multiple phone lines, a highly impractical and expensive method unsuitable for commercial use.During the mid-1950s, its laboratory work had produced another early test prototype capable of transmitting still images every two seconds over regular analog PSTN telephone lines. The images were captured by the Picturephone's compact Vidicon camera and then transferred to a storage tube or magnetic drum for transmission over regular phone lines at two-second intervals to the receiving unit, which displayed them on a small cathode-ray television tube. AT&T had earlier promoted its experimental video for telephone service at the 1939 New York World's Fair.
The more advanced Picturephone "Mod I" had public evaluation displays at Disneyland and the 1964 New York World's Fair, with the first transcontinental videocall between the two venues made on April 20, 1964. These demonstration units used small oval housings on swivel stands, intended to stand on desks. Similar AT&T Picturephone units were also featured at the Telephone Pavilion at Expo 67, an International World's Fair held in Montreal, Canada in 1967. Demonstration units were available at the fairs for the public to test, with fairgoers permitted to make videophone calls to volunteer recipients at other locations.
The United States would not see its first public videophone booths until 1964, when AT&T installed their earliest commercial videophone units, the Picturephone "Mod I", in booths that were set up in the lobbies of New York's Grand Central Terminal, the National Geographic Society Headquarters in Washington D.C., and Chicago's Prudential Building. The system was the result of decades of research and development at Bell Labs, its principal supplier, Western Electric, plus other researchers working under contract to the Bell Labs. However the use of reservation time slots and their cost of US$16 to $27 for a three-minute call at the public videophone booths greatly limited their appeal resulting in their closure by 1968.