Eidophor
Encyclopedia
An Eidophor was a television
projector used to create theater-sized images. 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
charges to deform an oil
surface.
by Dr Fritz Fischer and the Swiss Federal Institute of Technology
with the first prototype being unveiled in 1943. A patent was granted by the United States Patent and Trademark Office
(patent no. 2,391,451) to Friederich Ernst Fischer for the 'Process and appliance for projecting television pictures' on 25 December 1945.
Following the Second World War, Paramount Pictures
and 20th Century Fox
experimented with the concept of "theatre television" where television images would be broadcast onto cinema screens. Over 100 cinemas were set up with the process which was doomed due to financial losses and the U.S. Federal Communications Commission
(FCC) denying theatre owners their own UHF bands for presentation.
An original August 1952 magazine article in the Radio and Television News credits the development of the Eidophor to Dr Edgar Gretener. It was not until around the time of this article that Gretener took a lead in commercialising the Eidophor, following Fischer’s death in 1947.
Eidophors used an optical system somewhat similar to a conventional movie projector
but substituted a slowly-rotating mirrored disk or dish for the film. The disk was covered with a thick transparent oil and through the use of a scanned electron
beam, electrostatic charges could be deposited onto the oil, causing the surface of the oil to deform. Light was shone on the disc via a striped mirror consisting of strips of reflective material alternated 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 discharged and smoothed the ripples in the oil, readying it for re-use on another television frame.
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
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
.
Simple Eidophors produced black-and-white images. Later units used a color wheel
(equivalent to the color television
standard CBS
tried to bring to the market against RCA
/NBC
's FCC-approved NTSC
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 eighty 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. The new devices were smaller and cheaper and produced comparable results. Current technologies
include the Liquid Crystal Display (LCD) and Digital Light Processing (DLP) projectors, both of which produce superior results from easily portable devices.
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
projector used to create theater-sized images. 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
Electrostatics is the branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges....
charges to deform an oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
surface.
Origins and use
The idea for the original Eidophor was conceived in 1939 in ZurichZürich
Zurich is the largest city in Switzerland and the capital of the canton of Zurich. It is located in central Switzerland at the northwestern tip of Lake Zurich...
by Dr Fritz Fischer and the Swiss Federal Institute of Technology
ETH Zurich
The Swiss Federal Institute of Technology Zurich or ETH Zürich is an engineering, science, technology, mathematics and management university in the City of Zurich, Switzerland....
with the first prototype being unveiled in 1943. A patent was granted by the United States Patent and Trademark Office
United States Patent and Trademark Office
The United States Patent and Trademark Office is an agency in the United States Department of Commerce that issues patents to inventors and businesses for their inventions, and trademark registration for product and intellectual property identification.The USPTO is based in Alexandria, Virginia,...
(patent no. 2,391,451) to Friederich Ernst Fischer for the 'Process and appliance for projecting television pictures' on 25 December 1945.
Following the Second World War, Paramount Pictures
Paramount Pictures
Paramount Pictures Corporation is an American film production and distribution company, located at 5555 Melrose Avenue in Hollywood. Founded in 1912 and currently owned by media conglomerate Viacom, it is America's oldest existing film studio; it is also the last major film studio still...
and 20th Century Fox
20th Century Fox
Twentieth Century Fox Film Corporation — also known as 20th Century Fox, or simply 20th or Fox — is one of the six major American film studios...
experimented with the concept of "theatre television" where television images would be broadcast onto cinema screens. Over 100 cinemas were set up with the process which was doomed due to financial losses and the U.S. Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
(FCC) denying theatre owners their own UHF bands for presentation.
An original August 1952 magazine article in the Radio and Television News credits the development of the Eidophor to Dr Edgar Gretener. It was not until around the time of this article that Gretener took a lead in commercialising the Eidophor, following Fischer’s death in 1947.
Eidophors used an optical system somewhat similar to a conventional movie projector
Movie projector
A movie projector is an opto-mechanical device for displaying moving pictures by projecting them on a projection screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras.-Physiology:...
but substituted a slowly-rotating mirrored disk or dish for the film. The disk was covered with a thick transparent oil and through the use of a scanned electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
beam, electrostatic charges could be deposited onto the oil, causing the surface of the oil to deform. Light was shone on the disc via a striped mirror consisting of strips of reflective material alternated 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 discharged and smoothed the ripples in the oil, readying it for re-use on another television frame.
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
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
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 visual amplification
Live performance events including theater, music, dance, opera, use production equipment and services like: staging, scenery, mechanicals, sound, lighting, video, special effects, transport, packaging, communications, costume and makeup to convince live audience members that there is no better...
.
Simple Eidophors produced black-and-white images. Later units used a color wheel
Color wheel
A color wheel or color circle is an abstract illustrative organization of color hues around a circle that shows relationships between primary colors, secondary colors, complementary colors, etc....
(equivalent to the color television
Color television
Color television is part of the history of television, the technology of television and practices associated with television's transmission of moving images in color video....
standard CBS
CBS
CBS Broadcasting Inc. is a major US commercial broadcasting television network, which started as a radio network. The name is derived from the initials of the network's former name, Columbia Broadcasting System. The network is sometimes referred to as the "Eye Network" in reference to the shape of...
tried to bring to the market against RCA
RCA
RCA Corporation, founded as the Radio Corporation of America, was an American electronics company in existence from 1919 to 1986. The RCA trademark is currently owned by the French conglomerate Technicolor SA through RCA Trademark Management S.A., a company owned by Technicolor...
/NBC
NBC
The National Broadcasting Company is an American commercial broadcasting television network and former radio network headquartered in the GE Building in New York City's Rockefeller Center with additional major offices near Los Angeles and in Chicago...
's FCC-approved NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...
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 eighty 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
Comparison of display technology
This is a comparison of various properties of different display technologies.- General characteristics :- Temporal characteristics :Different display technologies have vastly different temporal characteristics, leading to claimed perceptual differences for motion, flicker, etc.The figure shows a...
in the 1990s brought about the end of the Eidophor. The new devices were smaller and cheaper and produced comparable results. Current technologies
Large-screen television technology
Large-screen television technology developed rapidly in the late 1990s and 2000s. Various thin screen technologies are being developed, but only the liquid crystal display , plasma display and Digital Light Processing were released on the public market...
include the Liquid Crystal Display (LCD) and Digital Light Processing (DLP) projectors, both of which produce superior results from easily portable devices.