Electron stimulated luminescence
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Electron Stimulated Luminescence (ESL) is light produced by accelerated electrons hitting a phosphor (fluorescent) surface in a process known as cathodoluminescence.[1][2][3][4] This is the process of light generation in a cathode ray tube (CRT) display, but lamps are built without magnetic or electrostatic deflection of the electron beam.[5]
A cathodoluminescent light has a transparent glass envelope coated on the inside with a light-emitting phosphor layer. Electrons emitted from a cathode strike the phosphor; the current returns through a transparent conductive coating on the envelope. The phosphor layer emits light through the transparent face of the envelope. The system has a power supply providing at least five thousand volts to the light emitting device, and the electrons transiting from cathode to anode are essentially unfocused. Additional circuits allow triac-type dimmers to control the light level.[6] Lights produced so far have a color rendering index of 85. The energy consumption can be 70% less than that of an incandescent light bulb, which produces light by heating a thin filament to incandescence. Lifetimes can be as long as 10,000 hours, five times longer than an incandescent light bulb's.[7]
ESL lamps do not use mercury, as do fluorescent lamps, which produce light by electrically exciting mercury vapor, which in turn radiates UV light towards a phosphor layer that converts the light into the visible spectrum.[8] The first commercially available ESL product was a reflector bulb. A standard pear shaped light bulb is planned for 2013, for the European and Middle East markets.
Independent product testing [citation needed] suggests ESL boasts better light quality than both LED and CFL, with full dimmability. Drawbacks include a slightly larger-than-normal base (which favors newer recessed "can" installations) and a slight delay in illumination when switched on, similar to CFLs.[9]
See also
- CRT projector
- Cathode ray tube (CRT)
- Electroluminescence
- Electroluminescent display (ELD) - Light through electric current
- Fluorescence
- Fluorescent lamp - Light through excited atoms in a plasma
References
- ↑ "Vu1 Corporation sees bright future for ESL light bulbs -- Engadget". 100902 engadget.com
- ↑ "Company Claims ESLs to be the Future of Light Bulbs (w/ Video)". 100902 physorg.com
- ↑ "Are ESL bulbs better than CFL or LED? – Crave - CNET". 100902 news.cnet.com
- ↑ greenprophet.com - Are ESLs A Mercury-Free Replacement for CFL Lights? | Green Prophet, 2012-03-12
- ↑ "The Promise of a Better Light Bulb?". The New York Times. 9 April 2009.
- ↑ http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7834553.PN.&OS=PN/7834553&RS=PN/7834553
- ↑ "Newest Lightbulb Tech Combines Advantages of Incandescent, Fluorescent, and LED". 100902 popsci.com
- ↑ ""Will ESL Light Bulbs Beat LEDs?"". Forbes.
- ↑ http://www.diylife.com/2011/01/26/esl-light-bulbs-diy-product-review/
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