An Eidophor was a
video projector
A video projector is an image projector that receives a video signalling (telecommunication), signal and projects the corresponding image on a projection screen using a lens (optics), lens system. Video projectors use a very bright ultra-high-per ...
used to create theater-sized images from an
analog video
Video is an electronic medium for the recording, copying
Copying is the duplication of information or an artifact based on an instance of that information or artifact, and not using the process that originally generated it. With analog f ...
signal. The name Eidophor is derived from the Greek word-roots ''eido'' and ''phor'' meaning 'image' and 'bearer' (carrier). Its basic technology was the use of
electrostatic
Electrostatics is a branch of physics that studies electric charges at rest (static electricity).
Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber ...
charges to deform an
oil
An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...
surface.
Origins and use
The idea for the original Eidophor was conceived in 1939 in
Zurich by Swiss physicist
Fritz Fischer
Fritz Fischer (5 March 1908 – 1 December 1999) was a German historian best known for his analysis of the causes of World War I. In the early 1960s Fischer advanced the controversial thesis at the time that responsibility for the outbreak of the ...
, professor at the ''Labor für technische Physik'' of the
Swiss Federal Institute of Technology, with the first prototype being unveiled in 1943. A basic patent was filed on November 8, 1939, in
Switzerland
). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...
[Monika Burri]
''Der Eidophor-Projektor.''
ETH History 1855 - 2005. Retrieved 26 September 2019 and granted by the
United States Patent and Trademark Office
The United States Patent and Trademark Office (USPTO) is an agency in the U.S. Department of Commerce that serves as the national patent office and trademark registration authority for the United States. The USPTO's headquarters are in Alexa ...
(patent no. 2,391,451) to Friederich Ernst Fischer for the ''Process and appliance for projecting television pictures'' on 25 December 1945.
During the Second World War,
Edgar Gretener
Edgar Gretener (2 March 1902 in Lucerne – 21 October 1958 in Zurich) was a Swiss electrical engineer.
Gretener was the twelfth of 14 siblings. He studied electrical engineering at Swiss Federal Institute of Technology (ETH Zurich), where he re ...
worked together with Fischer at the Institute of Technical Physics to develop a prototype. When Gretener launched his own company ''Dr. Edgar Gretener AG'' in 1941 to develop
enciphering equipment for the Swiss army, he stopped working on Eidophor.
Hugo Thiemann
Hugo Thiemann (February 2, 1917 – June 10, 2012) was a Swiss R&D manager and visionary. He was a founding member of the ''Club of Rome''.
Life
Hugo Ernst Thiemann was born in Heiden, Switzerland, then educated in nearby St. Gallen, Switzerland ...
took over this responsibility at the ETH.
[Hugo Thiemann: ''Fernsehbilder im Kino – Mit dem Eidophor beeindruckt die GRETAG Hollywoodgrössen''. In: Franz Betschon et al. (editors): ''Ingenieure bauen die Schweiz – Technikgeschichte aus erster Hand'', pp. 439–445, Verlag Neue Zürcher Zeitung, Zurich 2013, ] After six years of work on this project at the ETH, Thiemann moved together with the project to the company ''Dr. Edgar Gretener AG'', which was licensed by the ETH to further develop Eidophor, following Fischer's death in 1947.
An original August 1952 magazine article in the ''Radio and Television News'' credits the development of the Eidophor to Edgar Gretener.
Following the Second World War, a first demonstration of an Eidophor system as a cinema video projector was organized in the Cinema Theater REX in Zurich to show successfully a TV broadcast in April 1958.
An even more promising perspective was the interest of
Paramount Pictures
Paramount Pictures Corporation is an American film and television production company, production and Distribution (marketing), distribution company and the main namesake division of Paramount Global (formerly ViacomCBS). It is the fifth-oldes ...
and
20th Century Fox
20th Century Studios, Inc. (previously known as 20th Century Fox) is an American film production company headquartered at the Fox Studio Lot in the Century City area of Los Angeles. As of 2019, it serves as a film production arm of Walt Dis ...
which experimented with the concept of "theatre television", where television images would be broadcast onto cinema screens. Over 100 cinemas were set up for the project, which failed because of financial losses and the refusal of the U.S.
Federal Communications Commission
The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdiction ...
(FCC) to grant theatre owners their own
UHF bands for presentation.
Eidophors used an optical system somewhat similar to a conventional
movie projector
A movie projector is an optics, opto-mechanics, mechanical device for displaying Film, motion picture film by projecting it onto a movie screen, screen. Most of the optical and mechanical elements, except for the illumination and sound devices ...
, but substituted a slowly rotating mirrored disk or dish for the film. The disk was covered with a thin film of transparent high-viscosity oil, and through the use of a scanned
electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary particles because they have no kn ...
beam, electrostatic charges could be deposited onto the oil, causing its surface to deform. Light was shone on the disc by a striped mirror consisting of strips of reflective material alternating with transparent non-reflective areas. Areas of the oil unaffected by the electron beam would allow the light to be reflected directly back to the mirror and towards the light source, whereas light passing through deformed areas would be displaced and would pass through the adjacent transparent areas and onwards through the projection system. As the disk rotated, a
doctor blade
In printing the doctor blade (from ''ductor blade'') removes the excess ink from the smooth non-engraved portions of the anilox roll and the land areas of the cell walls. Doctor blades are also used in other printing and coating processes, such as ...
discharged and smoothed the ripples in the oil, readying it for re-use on another television frame.
[Ernst Baumann]
''DER EIDOPHOR - EINE SCHWEIZERISCHE ENTWICKLUNG DER FERNSEH-GROSSPROJEKTION.''
Neujahrsblatt, Naturforschende Gesellschaft in Zürich, Jahr 1961. Gebr. Fretz AG, Zürich. Retrieved 26 September 2019
![Eidophor display Mission Control Center Houston](https://upload.wikimedia.org/wikipedia/commons/0/0a/Eidophor_display_Mission_Control_Center_Houston.jpg)
The Eidophor was a large and cumbersome device and not commonly used until there was a need for good-quality large-screen projection. This opportunity arose as part of the
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
space program, where the technology was deployed in mission control.
Eidophors were also used in stadiums by touring music groups for
live event visual amplification
Live event support includes staging, scenery, mechanicals, sound, lighting, video, special effects, transport, packaging, communications, costume and makeup for live performance events including theater, music, dance, and opera. They all share th ...
.
Simple Eidophors produced black-and-white images. Later units used a
color wheel
A color wheel or color circle is an abstract illustrative organization of color hues around a circle, which shows the relationships between primary colors, secondary colors, tertiary colors etc.
Some sources use the terms ''color wheel'' & ' ...
(equivalent to the
color television
Color television or Colour television is a television transmission technology that includes color information for the picture, so the video image can be displayed in color on the television set. It improves on the monochrome or black-and-white t ...
standard
CBS
CBS Broadcasting Inc., commonly shortened to CBS, the abbreviation of its former legal name Columbia Broadcasting System, is an American commercial broadcast television and radio network serving as the flagship property of the CBS Entertainm ...
tried to bring to the market against
RCA
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
/
NBC
The National Broadcasting Company (NBC) is an Television in the United States, American English-language Commercial broadcasting, commercial television network, broadcast television and radio network. The flagship property of the NBC Enterta ...
's FCC-approved
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
system, and today's
DLP projection system) to produce red, green, and blue fields. The last models produced used separate red, green, and blue units in a single case. The Eidophor was 80 times brighter than CRT projectors of the time. The last Eidophors were able to project colour images of up to 18 metres in width.
Advances in
projection television technology in the 1990s brought about the end of the Eidophor. An early prototype of a new type of projector with limited resolution using a
passive matrix-addressed liquid-crystal display
A liquid-crystal display (LCD) is a flat-panel display
A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipmen ...
was shown at a conference in
San Francisco
San Francisco (; Spanish language, Spanish for "Francis of Assisi, Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the List of Ca ...
by Swiss engineer
Peter J. Wild already in 1972.
The new devices, using
active matrix addressing
Active may refer to:
Music
* ''Active'' (album), a 1992 album by Casiopea
* Active Records, a record label
Ships
* ''Active'' (ship), several commercial ships by that name
* HMS ''Active'', the name of various ships of the British Royal ...
of LCDs were smaller and cheaper and produced results comparable with Eidophor.
Current technologies include liquid-crystal display (LCD) and digital light processing (DLP) projectors, both of which produce superior results from easily portable devices.
See also
*
Comparison of display technology
This is a comparison of various properties of different display technologies.
General characteristics
Major technologies are Cathode ray tube, CRT, LCD and its derivatives (Quantum dot display, LED backlit LCD, WLCD, OLCD), Plasma display, P ...
*
Talaria projector Talaria was the brand name of a large-venue video projector from General Electric introduced in 1983.
Light from a Xenon arc lamp was modulated by a light valve consisting of a rotating glass disc that was continuously re-coated with a viscous o ...
*
Telecinema
The Telecinema was a small cinema built especially for the Festival of Britain's London South Bank Exhibition in the summer of 1951. It was situated between Waterloo station and the Royal Festival Hall.
The Telecinema was one of the most popula ...
*
Closed-circuit television
Closed-circuit television (CCTV), also known as video surveillance, is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly t ...
Notes
References
*Robertson, A. (1976) Projection Techniques:TV, pp. 149–150, in Video Year Book 1977, Poole, The Dolphin Press.
*Johannes, Heinrich (1989) The History of the EIDOPHOR Large-Screen Television Projector, GRETAG AG, Regensdorf, Switzerland
*Meyer, Caroline (2009) Der Eidophor: Ein Grossbildprojektionssystem zwischen Kino und Fernsehen 1939–1999. (Interferenzen – Studien zur Kulturgeschichte der Technik, 15). Chronos-Verlag, Zurich 2009, {{ISBN, 978-3-0340-0988-1.
External links
The history and workings of Eidophor projection*
ttps://www.youtube.com/watch?v=3-BvMcqEc98 Eidophor: 1950's Steampunk Video Projection Technology presentation by Mike Harrison at the 2016 Hackaday Belgrade conference
Make It Better Than Just Being There 1992 Eidophor promotional film, hosted by the Museum for Communication
Projectors
Television technology
Swiss inventions