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APPLICATIONSINFORMATION
AI-002Rev. C 10/97PAGE 1 OF 3
DESCRIPTION (cont.)
transducer converting electrical energy into lightenergy. The
technology of miniature CCFLsand associated electronics
advancedtremendously with the advent of the laptopcomputer for
which the CCFL is typically thelight source for the LCD
display.
Cold cathode refers to the type of electrode inthe lamp ends.
Cold cathode electrodes do notrely on additional means of thermonic
emission
besides that created by the electrical discharge
through the tube. In contrast, the architecturaltype of hot
cathode fluorescent lamp has anelectrode in the form of a filament,
which isheated from current passing through it,producing enhanced
emissions from the lamp.Essential advantages of cold cathode lamps
aretheir ability for miniaturization because of thesimplified
electrode, reduced complexity of thedrive electronics, increased
durability, andimproved lamp life.
Figure 1
CONSTRUCTION AND FUNCTION
The typical CCFL is a hollow glass cylindercoated inside with a
phosphor materialcomposed of rare earth elements and sealed witha
gettered electrode at both ends. The lampsnormally contain 2-10
milligrams of mercuryalong with a mixture of gases, such as argon
andneon. Ultraviolet energy at 253.7nm is producedby ionization of
the mercury and penning gasmixture by the application of high
voltage to the
electrodes. The ultraviolet energy from themercury discharge
stimulates the phosphorcoating, producing light output. Lamp
phosphoris typically composed of rare earth elementssuch as zinc
silicate and various types of halophosphates, increasing the
wavelength of the 253.7nm energy to the visible light region,
inrelation to Stokes Law as applied toluminescence.
(818) 896-0019 (800) 421-7244 Fax: (818) 897-3056
http://www.jkllamps.com E-mail: [email protected]
8/6/2019 COLD CATHODE FLUORESCENT LAMPS (CCFLs)
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AI-002Rev. C 10/97PAGE 3 OF 3
CONSTRUCTION AND FUNCTION(cont.)
The visible light portion of the electromagneticspectrum is
referred to as the photopic region,which is energy in the 380nm to
780nm range.
The most widely used white light CCFL lampphosphors have been
compounded for goodcolor rendering when used as an LCD
displaybacklight. These phosphors are referred to as
RGB, being composed of Red-Green-Bluefluorescent compounds mixed
in the appropriateratio. With a lamp utilizing RGB phosphors,
theability exists to alter the ratio of the components,hence
changing the characteristics of the lamp'scolor temperature
(perceived warmth or coolnessof light). Light output from a
particularphosphor is described in degrees Kelvin with atypical RGB
phosphor for CCFL being 5600,which approximates daylight. A cooler
color,hence higher degrees Kelvin, is perceived as abluer
light.
REFERENCE READING
1) Cayless, MA.; Marsden, AM. Lamps andLighting Baltimore, MD:
Edward Arnold,3rd edition 1983.
2) Derganc, C. Thomas Edison and his electriclighting system.
IEEE spectrum, February1979. Pp. 50-59.
3) Fitt, B.; Thornley, J. Lighting Technology.Oxford, UK:
Butterworth-Heinemann, 1997.Pp. 27-46, 75-104.
4) Rabusin, E. Dr. Getters for Lamps. Milan,Italy: SAES Getters
S.p.A., 2 nd edition 1982.Pp. 31-39.
5) Williams, J. The Art and Science of AnalogCircuit Design.
Boston, MA: Butterworth-Heinemann, 1995. Pp. 139-193.
INFORMATION ACCURACY
Information furnished herein by JKL Components Corporation is
believed to be accurate and reliable. However,no responsibility is
assumed for its use. JKL Components Corporation makes no
representation that the
interconnection of its devices, as described herein, will not
infringe on existing patent rights.
LIFE SUPPORT POLICY
JKL COMPONENTS CORPORATION'S PRODUCTS ARE NOT AUTHORIZED FOR USE
AS CRITICAL COMPONENTS IN LIFE SUPPORTDEVICES OR SYSTEMS WITHOUT
THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF JKL COMPONENTS
CORPORATION.
As used herein:
a. Life support devices or systems are devices or systems which
(1) are intended for surgical implant into the body, or (2) support
or sustain life and whose failure to perform when properly used in
accordance with instructions for use provided in the labeling can
be reasonably expected toresult in a significant injury to the
user.
b. A critical component is any component in a life support
device or system whose failure to perform can be reasonably
expected to cause the failure of the life support device or system
or to affect its safety or effectiveness.
(818) 896-0019 (800) 421-7244 Fax: (818) 897-3056
http://www.jkllamps.com E-mail: [email protected]
