Kálmán Tihanyi

From European Patent Office abstract of Tihanyi's 1928 application Improvements in television apparatus[3]

Kalman Tihanyi as a scientist of British Air Ministry)

Born in Üzbég, Kingdom of Hungary (now Zbehy, Slovakia), After graduating in the local elementary school, his parents enrolled him in the Vocational School of Electrical Engineering in Pozsony (now Bratislava), where he filed his first patent application for the Hungarian Patent Office in 1913, at the age of sixteen (!), The title of the patent was "Pocket device for light handling of photographic plates". The first contract of his life with a Viennese company, which purchased his equipment for the central, wireless switching on and off of road lights. At that time, he continued his high school studies in Vác, he graduated here as well, and the following year, in 1916, he entered the Hungarian Royal Army as a volunteer. As an officer candidate for the 4th Army Artillery Regiment, the young man first handled the roaring cannons on the eastern front and was then transferred to Transylvania, where he took part in the battles at one of the most important crossings in the Eastern Carpathians, the Ojtozi Strait. His brave standing was awarded a bronze medal of valor and then the rank of lieutenant. Soon, however, he was transferred to one of the most important military ports of the Austro-Hungarian Monarchy in Pula, where he no longer served as a soldier in a combat unit, but as a radio engineer, and for the first time in his life he “tasted” military technical developments. He designed a remotely controlled igniter for timing and detonating underwater shafts, and his land mine was credited as a distinguished military invention.

After World War I, Kálmán Tihanyi, who returned to civil life, continued his studies at the Royal Hungarian Joseph University of Technology in Budapest (today: Budapest University of Technology and Economics, commonly known as the Technical University), where the young man who has recently lost his father was left without any income. Luckily, he found a friend in Professor Imre Pöschl, who recognized his talent, while he could sell more and more patents and inventions, he could enjoy an increasing income, thus he could support his widowed mother and nine siblings.

Tihany's attention was already drawn to the attempts to create television during World War I. After Tihanyi studied Maxwell's equations, he discovered a new hithero unknown physical phenomenon. 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 Tihanyi in the beginning of 1924.[4] His final design was patented under the name "Radioskop" in 1926. He described his cathode ray tube, charge-storage television system in not one, but in three versions - wired, wireless, and color, which meant he was thinking of color television even when black and white films were made in the vast majority of the film industry. His patent application contained 42 pages detailing its design and mass production. It is recorded in UNESCO's Memory of the World Programme.[5] Though it bears certain similarities to earlier proposals employing a cathode ray tube (CRT) for both transmitter and receiver, Tihanyi's system represented a radical departure. Like the final, improved version Tihanyi would patent in 1928, it embodied an entirely new concept in design and operation, building upon a technology that would become known as the "storage principle". This technology involves the maintenance of photoemission from the light-sensitive layer of the detector tube between scans. By this means, accumulation of charges would take place and the "latent electric picture" would be stored. Tihanyi filed two separate patent applications in 1928 then extended patent protection beyond Germany,[6][7] filing in France,[8] the United Kingdom,[9][10] the United States, and elsewhere.

In 1928, Tihanyi went to Berlin, where the development of mechanical television involving Nipkow disks had already been begun by the German Post Office and the larger manufacturers. He set up his own laboratory in Berlin, where he made his first experimental picture tube with his two younger brother, who also was electrical engineer. The invention was received with enthusiasm by Telefunken and Siemens, but in the end they opted to continue with the development of mechanical television.[11] Then he was approached by the American Radio Corporation of America (RCA), contracted with him to purchase his patent, and began laboratory development of the image resolution tube. After a few months, the first well-functioning American camera tubes which based on Tihanyi's ideas were completed by Vladimir Zworykin at RCA, and the new television system was named the iconoscope.

In 1929, he moved to London, where he was invited to work on television guidance for defense applications, building prototypes of a camera for remotely guided aircraft for the British Air Ministry, and later adapting it for the Italian Navy.[11][12] The solutions of the technology what Tihanyi depicted in his 1929 patent were so influential, that American UAV producing companies still used many of its ideas even half century later, until the mid 1980s.[13] In 1929, he invented the World's first infrared-sensitive (night vision) electronic television camera for anti-aircraft defense in Britain.[14][15] In London he was commisioned with the designing of the remote-controll devices and fire control systems for tanks, anti-aircraft guns and anti-aircraft reflectors for Britain.

Tihanyi's U.S. patents for his display and camera tubes, assigned to RCA, were issued in 1938 and 1939, respectively.[1][2]

In 1936 Tihanyi described the principle of "plasma television" and conceived the first flat-panel television system.[16] It involved a single “transmission point” being moved at great speed behind a grid of cells arranged in a thin panel display, which would be excited to different levels by varying the voltages to the point[17]

In a Technikatörténeti Szemle article, subsequently reissued on the internet, entitled The Iconoscope: Kalman Tihanyi and the Development of Modern Television, Tihanyi's daughter Katalin Tihanyi Glass notes that her father found the "storage principle" included a "new physical phenomenon", the photoconductive effect:

The earliest reference to the new phenomenon this writer found is in an article, entitled "About the Electrical Television", written by Kalman Tihanyi and published on May 3, 1925, nearly one year prior to his first application for patent on an all-electronic television system. Although the inventor does not use the term "storage principle" of "storage effect", the description of the new phenomenon he had discovered implies that that is exactly what he had in mind. Thus, he wrote:

"The writer of this article has studied thoroughly all phenomena known from the current state of the physical sciences which could be applied to the solution of the problem and on the basis of control calculations found them unfit for the achievement of the minimally required 1/80,000 s efficiency at the transmitting station. However, during experimentation a new physical phenomenon was discovered, under which the optical and the electrical effect is practically simultaneous. In fact displacement between the two effects could not be detected with our instruments, although the possibility exists for a displacement of 1/400,000,000 of a second based on Maxwell's equations in regard to a related phenomenon. This means that under this phenomenon not only the desirable 1/150,000 second changes, but 1/400 million changes can be followed" (K. Tihanyi: "Az elektromos távolbavetítésről" ("About electric teleprojection"), Nemzeti Újság magazine, May 3, 1925, p. 23). (Emphasis added.)

An investigation of various dictionaries and lexicons confirms that, indeed, in addition to the photoelectric (or photoemissive) effect, storage television technology also involves an entirely different phenomenon.

Evident from these characterizations is that while under the photoelectric effect bound electrons released from such photosensitive materials vary linearly with the frequency of the radiation, "that is for each incident photon an electron is ejected", under the storage effect a photoconductive and photovoltaic phenomenon occurs where ("apart from the liberation of electrons from metals") when photons are absorbed in a p-n junction (in a semiconductor) or metal-semiconductor junction, "new free charge carriers are produced", (photoconductive effect) and where "the electric field in the junction region causes the new charge carriers to move, creating a flow of current in an external circuit without the need for a battery", (photovoltaic effect) (The International Dictionary of Physics and Electronics, N.Y. 1956, 1961, pp. 126, 183, 859-861, 863, 1028-1028, 1094-1095).

The Concise Dictionary of Physics under the heading, "Photoelectric Cells", differentiates between "the original photocells" (which utilized photoemission form a photosensitive surface and their attraction by the anode) and "the more modern photocells which utilize the photoconductive and photovoltaic effect" (The Concise Dictionary of Physics, Oxford, 1985).[18]