Neon sign
In the
The signage industry has declined in the past several decades, and cities are now concerned with preserving and restoring their antique neon signs.History
The neon sign is an evolution of the earlier
The discovery of neon in 1898 by British scientists
In 1923, Georges Claude and his French company Claude Neon introduced neon gas signs to the United States
The next major technological innovation in neon lighting and signs was the development of fluorescent tube coatings.
Suddenly we were in down-town Seattle and lights were exploding around me like skyrockets on the Fourth of July. Red lights, blue lights, yellow lights, green, purple, white, orange, punctured the night in a million places and tore the black satin pavement to shreds. I hadn’t seen neon lights before. They had been invented, or at least put in common use, while I was up in the mountains and in that short time the whole aspect of the world had changed. In place of dumpy little bulbs sputteringly spelling out Café or Theatre, there were long swooping spirals of pure brilliant colour. A waiter outlined in bright red with a blazing white napkin over his arm flashed on and off over a large Café. Puget Sound Power and Light Company cut through the rain and darkness, bright blue and cheery. Cafês, theatres, cigar stores, stationery stores, real estate offices with their names spelled out in molten colour, welcomed me to the city.
— Betty MacDonald, recalling 1931, Anybody Can Do Anything
Fabrication
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Neon tube signs[23][24][25][26] are produced by the craft of bending glass tubing into shapes. A worker skilled in this craft is known as a glass bender, neon bender or tube bender. The neon tube is made out of 4 or 5-foot long straight sticks of hollow glass sold by sign suppliers to neon shops worldwide, where they are manually assembled into individual custom designed and fabricated lamps.
Tubing in external diameters ranging from about 8–15 mm with a 1 mm wall thickness is most commonly used, although 6 mm tubing is now commercially available in colored glass tubes. The tube is heated in sections using several types of burners that are selected according to the amount of glass to be heated for each bend. These burners include ribbon, cannon, or crossfires, as well as a variety of gas torches. Ribbon burners are strips of fire that make the gradual bends, while crossfires are used to make sharp bends.
The interior of the tubes may be coated with a thin phosphorescent powder coating, affixed to the interior wall of the tube by a binding material. The tube is filled with a purified gas mixture, and the gas ionized by a high voltage applied between the ends of the sealed tube through cold cathodes welded onto the ends. The color of the light emitted by the tube may be just that coming from the gas, or the light from the phosphor layer. Different phosphor-coated tubing sections may be butt welded together using glass working torches to form a single tube of varying colors, for effects such as a sign where each letter displays a different color letter within a single word.
"Neon" is used to denote the general type of lamp, but neon gas is only one of the types of tube gases principally used in commercial application. Pure neon gas is used to produce only about one-third of the colors (mostly shades of
Each type of neon tubing produces two different possible colors, one with neon gas and the other with argon/mercury. Some "neon" tubes are made without phosphor coatings for some of the colors. Clear tubing filled with neon gas produces the ubiquitous yellowish orange color with the interior plasma column clearly visible, and is the cheapest and simplest tube to make. Traditional neon glasses in America over 20 years old are lead glass that are easy to soften in gas fires, but recent environmental and health concerns of the workers has prompted manufacturers to seek more environmentally safe special soft glass formulas. One of the vexing problems avoided this way is lead glass' tendency to burn into a black spot emitting lead fumes in a bending flame too rich in the fuel/oxygen mixture. Another traditional line of glasses was colored soda lime glasses coming in a myriad of glass color choices, which produce the highest quality, most hypnotically vibrant and saturated hues. Still more color choices are afforded in either coating, or not coating, these colored glasses with the various available exotic phosphors.
Long lifetime
Tube bending
Neon sign makers bend heated glass tubes, carefully following a pattern. They use a blow hose to keep the tube's shape and avoid overheating sections. Bends are tricky, requiring quick work before the glass hardens. Mistakes are a pain, potentially forcing a restart. Tubes are welded together, pumped clean, and filled with mercury. Any mistake after filling means scrapping the whole thing, as mercury fumes are dangerous. Completed tubes are connected in series, with proper insulation to prevent damage.
Bombardment
A cold cathode electrode is melted (or welded) to each end of the tube as it is finished. The hollow electrodes are also traditionally lead glass and contain a small metal shell with two wires protruding through the glass to which the sign wiring will later be attached. All welds and seals must be leak-proof at high vacuum before proceeding further.
The tube is attached to a manifold which is then attached to a high-quality vacuum pump. The tube is then evacuated of air until it reaches a vacuum level of a few torr. The evacuation is paused, and a high current is forced through the low-pressure air in the tube via the electrodes (in a process known as "bombarding"). This current and voltage is far above the level that occurs in final operation of the tube. The current depends on the specific electrodes used and the diameter of the tube but is typically in the 150 mA to 1,500 mA range, starting low and increasing towards the end of the process to ensure that the electrodes are adequately heated without melting the glass tube. The bombarding current is provided by a large transformer with an open-circuit voltage of roughly 15,000VAC to 23,000VAC. The bombarding transformer acts as an adjustable constant current source, and the actual voltage during operation depends on the length and pressure of the tube. Typically the operator will maintain the pressure as high as the bombarder will allow to ensure maximum power dissipation and heating. Bombarding transformers may be specially made for this use, or may be repurposed electrical utility distribution transformers (the type seen mounted on utility poles) operated backwards to produce a high voltage output.
This very high power dissipation in the tube heats the glass walls to a temperature of several hundred degrees Celsius, and any dirt and impurities within are drawn off in the gasified form by the vacuum pump. The greatest impurities that are driven off this way are the gases that coat the inside wall of the tubing by
While still attached to the manifold, the tube is allowed to cool while pumping down to the lowest pressure the system can achieve. It is then filled to a low pressure of a few
Heat processed neon tubes
An alternative way of processing finished neon tubes has also been used. Because the only purpose of bombardment by electrical means is to purify the interior of tubes, it is also possible to produce a tube by heating the tube externally either with a torch or with an oven, while heating the electrode with a radio frequency induction heating (RFIH) coil. While this is less productive, it creates a cleaner custom tube with significantly less cathode damage, longer life and brilliance, and can produce tubes of very small sizes and diameters, down to 6 mm OD. The tube is heated thoroughly under high vacuum without external electrical application, until the outgassed gases can be seen to have been totally depleted and the pressure drops to a high vacuum again. Then the tube is filled, sealed and the mercury dropped and shaken.
Electrical wiring
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The finished glass pieces are illuminated by either a
The standard traditional neon transformer, a magnetic shunt transformer, is a special non-linear type designed to keep the voltage across the tube raised to whatever level is necessary to produce the fixed current needed. The voltage drop of a tube is proportional to length and so the maximum voltage and length of tubing fed from a given transformer is limited. Generally, the loaded voltage drops to about 800 VAC at full current. The short-circuit current is about the same.[27]
Compact high frequency inverter-converter transformers developed in the early 1990s are used, especially when low
The most common current rating is 30 mA for general use, with 60 mA used for high-brightness applications like channel letters or architectural lighting. 120 mA sources are occasionally seen in illuminating applications, but are uncommon since special electrodes are required to withstand the current, and an accidental shock from a 120 mA transformer is much more likely to be fatal than from the lower current supplies.
The efficiency of neon lighting ranges between that of ordinary incandescent lights and that of fluorescent lamps, depending on color. On a per-watt basis, incandescents produce 10 to 20 lumens, while fluorescents produce 50 to 100 lumens. Neon light efficiency ranges from 10 lumens per watt for red, up to 60 lumens for green and blue when these colors result from internal phosphor coatings.[28]
Blocking out and coating
A highly opaque special black or gray glass paint can be used to "black out" parts of a tube, as between letters of a word. In most mass-produced low-priced signs today, clear glass tubing is coated with translucent paint to produce colored light. In this way, several different colors can be produced inexpensively from a single glowing tube. Over time, elevated temperatures, thermal cycling, or exposure to weather may cause the colored coating to flake off the glass or change its hue. A more expensive alternative is to use high-quality colored glass tubing, which retains a more stable appearance as it ages.
Applications
Light-emitting tubes form colored lines with which a text can be written or a picture drawn, including various decorations, especially in
In some applications, neon tubes are increasingly being replaced with
Neon illumination is valuable to invoke the 1940s or 1950s
Gallery
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Neon bowling alley sign
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Promotional signage neon
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Neon sign of a public sauna in Helsinki
See also
- Crackle tube
- Plasma globe
- Pundit Light
- Westinghouse Sign
- Timeline of lighting technology
- Neon Museum, Warsaw
References
- ISBN 978-93-90332-73-1.
- ^ ISBN 978-0-8147-8812-7.
The first commercial use was at a motor show in Paris in December 1910
- ^ "The Golden Age of Neon". 30 March 2021.
- ^ ISBN 978-0-8109-1299-1.
- ^ a b Bright, Arthur A. Jr. (1949). The Electric-Lamp Industry. MacMillan. Pages 221–223 describe Moore tubes. Pages 369–374 describe neon tube lighting. Page 385 discusses Risler's contributions to fluorescent coatings in the 1920s. Pages 388–391 discuss the development of the commercial fluorescent at General Electric in the 1930s.
- ^ Popper, Frank (2009). "Neon". Grove Art Online. Oxford University Press.
- ^ a b Thielen, Marcus (August 2005). "Happy Birthday Neon!". Signs of the Times. Archived from the original on 2012-03-03.
- ISBN 978-0-471-49946-6.
Plasma displays are closely related to the simple neon lamp.
- S2CID 20290119. Paid access.
- PMID 32297489.
- ISBN 978-1-4831-4521-1.
- ISBN 978-0-323-14095-9.
- ^ "Lamp Inventors 1880–1940: Moore Lamp". The Smithsonian Institution.
- ^ a b c Claude, Georges (November 1913). "The Development of Neon Tubes". The Engineering Magazine: 271–274.
- ^ ]
- doi:10.1080/14786440409463212. Fleming used a tube of neon, without electrodes, to explore the amplitudes of radio wavesby examining the intensity of the tube's light emission. He had obtained his neon directly from its discoverer, Ramsey.
- ^ Howard, John K. (February 2009). "OSA's First Four Presidents". Optics & Photonics News. Archived from the original on 2011-07-28. Retrieved 2009-02-21.
- ^ The dates of the show are listed at "Chronik 1901 – 1910/en". Mercedes Benz. Archived from the original on 2011-08-15. Retrieved 2010-11-25.
- ^ Testelin, Xavier. "Reportage – Il était une fois le néon No. 402". Retrieved 2010-12-06. Claude's 1910 demonstration of neon lighting lit the peristyle of the Grand Palais in Paris; this webpage includes a contemporary photograph that gives an impression of it. It is part of an extensive selection of images of neon lighting; see "Reportage – Il était une fois le néon".
- ISBN 978-1-4671-0929-1.
- ^ These anecdotes and the phrase "liquid fire" are often used in references discussing the first neon tube lights in Los Angeles, but the primary source is not provided. One example of a typical, tertiary reference is Bellis, Mary. "The History of Neon Signs: Georges Claude and Liquid Fire". ThoughtCo.
- ISBN 978-962-937-592-8.
- ISBN 978-0-944094-27-3.
- ^ "ST Media Group International | Publications". Signs of the Times. ST Media Group International. January 18, 2012. Archived from the original on 2012-01-19. Retrieved 2010-03-08.
- ^ "SignWeb website". ST Media Group International. Archived from the original on 2011-02-02. Retrieved 2011-03-08.
- ^ Strattman, Wayne (1997). "The Luminous Tube: An illuminating description of how neon signs operate". Signs of the Times. Retrieved 2010-12-10.
- ^ a b Neon, Claude, 1905; Neon Signs, Miller & Fink, 1935.
- ^ Caba, Randall L. "Neon and Fluorescents: A Circus of Similarities". SignIndustry.com. Retrieved 4 March 2011.
- ^ NeonGrand (January 2022). "How Much Electricity Do LED Neon Signs Consume". NeonGrand. Retrieved 2022-11-12.
- ^ "Lighting & LED". SignWeb. Media Group International. Retrieved 2012-03-06.
- ^ "Knowledge Center". Brighter Thinking. The Neon Group. Retrieved 2012-03-06.
- ^ Michael J. Auer (October 1991). "The Preservation of Historic Signs". US National Park Service. Retrieved 2021-10-11.
Further reading
- "2010 Top Ten Endangered Sites". Heritage Vancouver Society. Archived from the original on 2011-07-24. Retrieved 2010-12-05.
- Beech, Hannah (2023-12-09). "Where Did All the Hong Kong Neon Go?". The New York Times. Retrieved 2023-12-09.
- Bass, Shermakaye (2007-06-06). "Neon Museum saving Las Vegas' iconic signs". Los Angeles Times. Retrieved 2009-09-12.
- Crowley, David (September 2007). "Life in the Darkness". Creative Review. Retrieved 2021-10-11. Article about neon signage's flowering and decline in Warsaw and Poland.
- Keen, Judy (October 6, 2008). "Save neon signs, fans urge". USA Today.
- Strattman, Wayne (1997). Neon Techniques: Handbook of Neon Sign and Cold-Cathode Lighting, 4th edition. ST Media Group International. ISBN 978-0-944094-27-3. – industry standard reference on practices, methods, and technologies used by neon fabricators
External links
- Johansson, Feddy. "Svenska Neonskyltar". Collection of photographs of Swedish neon signs; text in Swedish.
- "Neon Muzeum". NeonMuzeum.com. Website of an organization devoted to preserving Polish neon signs; in English.