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A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light, and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent lamp; some types fit into light fixtures formerly used for incandescent lamps. The lamps use a tube which is curved or folded to fit into the space of an incandescent bulb, and a compact electronic ballast in the base of the lamp. Compared to general-service incandescent lamps giving the same amount of visible light, CFLs use one-fifth to one-third the electric power, and last eight to fifteen times longer. A CFL has a higher purchase price than an incandescent lamp, but can save over five times its purchase price in electricity costs over the lamp's lifetime.〔(【引用サイトリンク】 publisher=Energy Star )〕 Like all fluorescent lamps, CFLs contain toxic mercury〔(【引用サイトリンク】 publisher=National Public Radio )〕 which complicates their disposal. In many countries, governments have established recycling schemes for CFLs and glass generally. The principle of operation in a CFL bulb remains the same as in other fluorescent lighting: electrons that are bound to mercury atoms are excited to states where they will radiate ultraviolet light as they return to a lower energy level; this emitted ultraviolet light is converted into visible light as it strikes the fluorescent coating on the bulb (as well as into heat when absorbed by other materials such as glass). CFLs radiate a spectral power distribution that is different from that of incandescent lamps. Improved phosphor formulations have improved the perceived color of the light emitted by CFLs, such that some sources rate the best "soft white" CFLs as subjectively similar in color to standard incandescent lamps. White LED lamps now compete with CFLs for high-efficiency house lighting.〔Amber Angelle, "Will LED Light Bulbs Best Your CFLs and Incandescents?" (''Popular Mechanics'' August 4, 2010 ) accessed May 30, 2011〕 == History == The parent to the modern fluorescent lamp was invented in the late 1890s by Peter Cooper Hewitt. The Cooper Hewitt lamps were used for photographic studios and industries.〔 Edmund Germer, Friedrich Meyer, and Hans Spanner patented a high-pressure vapor lamp in 1927.〔 George Inman later teamed with General Electric to create a practical fluorescent lamp, sold in 1938 and patented in 1941.〔 Circular and U-shaped lamps were devised to reduce the length of fluorescent light fixtures. The first fluorescent bulb and fixture were displayed to the general public at the 1939 New York World's Fair. The spiral CFL was invented in 1976 by Edward E. Hammer, an engineer with General Electric,〔(【引用サイトリンク】title=Inventing Six Modern Electric Lamps: Compact Fluorescent – The Challenge of Manufacturing )〕 in response to the 1973 oil crisis. Although the design met its goals, it would have cost GE about $25 million to build new factories to produce the lamps, and thus the invention was shelved. The design was eventually copied by others.〔 In 1995, helical CFLs, manufactured in China, became commercially available.〔(【引用サイトリンク】title=Philips Tornado Asian Compact Fluorescent )〕 Since that time, their sales have steadily increased. In 1980, Philips introduced its model SL, which was a screw-in lamp with integral magnetic ballast. The lamp used a folded T4 tube, stable tri-color phosphors, and a mercury amalgam. This was the first successful screw-in replacement for an incandescent lamp. In 1985, Osram started selling its model EL lamp, which was the first CFL to include an electronic ballast.〔Raymond Kane, Heinz Sell ''Revolution in lamps: a chronicle of 50 years of progress (2nd ed.)'', The Fairmont Press, Inc. 2001 ISBN 0-88173-378-4 pp. 189–190.〕 Development of fluorescent lamps that could fit in the same volume as comparable incandescent lamps required the development of new, high-efficacy phosphors that could withstand more power per unit area than the phosphors used in older, larger fluorescent tubes.〔 File:Old compact fluorescent lamp.JPG|Philips SL, an early CFL File:Compact-Fluorescent-Bulb.jpg|A helical integrated CFL, one of the most popular designs in North America, since 1995, when a Chinese firm, Shanghai Xiangshan, marketed the first successful design.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Compact fluorescent lamp」の詳細全文を読む スポンサード リンク
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