Polygamy LED light - emitting diode basic knowledge
Author: Shenzhen Yuan Zhi Electronics Co., Ltd.Time:2018-03-01 17:15:39Views:2933【SML】
Nowadays,
the modern society has entered the information age, and the information
dissemination occupies an increasingly important position. At the same
time, people are demanding higher and higher...
label:
Nowadays,
the modern society has entered the information age, and the information
dissemination occupies an increasingly important position. At the same
time, people are demanding higher and higher visual media, which
requires the media to reflect promptly, realistically (real-timely),
catchy (colorful, lifelike) In
recent years, with the rapid development of microelectronics
technology, automation technology and computer technology, the
semiconductor manufacturing technology has matured, resulting in smaller
and smaller LED display dots and higher and higher resolutions Can display the light of the three primary colors (red, green,
blue) integrated into one, to full-color effect, making the LED display
is expanding the scope of application.
LED concept definition:
LED
is taken from the abbreviation of Light Emitting Diode three words, the
Chinese translated as "light-emitting diode", as the name suggests
light-emitting diode is a kind of electronic devices can be converted
into light energy with diode characteristics. At
present, different light-emitting diodes emit different wavelengths of
light from infrared to blue. Currently, light-emitting diodes that emit
purple and even ultraviolet light have also been born. In addition there are blue LED coated with phosphor, the blue light into white light LED.
LED color and technology:
The
materials used to make the LEDs are different and produce photons with
different energies, whereby the wavelength of the light emitted by the
LED, that is, the spectrum or color, can be controlled. The
first LED used in history was a gallium arsenide (Ga) with a forward PN
junction drop (VF, which can be interpreted as a light-on or operating
voltage) of 1.424V and emitted light of the infrared spectrum . Another
commonly used LED material is gallium (P) gallium (Ga), with a positive
PN junction pressure drop of 2.261 V, emitting a green light. Based
on these two materials, the early LED industry using GaAs1-xPx material
structure, in theory, can produce from infrared to green light at any
wavelength of any wavelength, LED light-emitting diodes, LED
light-emitting diode knowledge subscript X on behalf of the
phosphorus-substituted arsenic The percentage of elements.
Generally through the PN junction voltage drop can determine the wavelength of the LED color. Typical of which are GaAs0.6P0.4 red LED, GaAs0.35P0.65 orange LED, GaAs0.14P0.86 yellow LED and so on. As
a result of the manufacture of gallium, arsenic, phosphorus three
elements, so commonly known as these three LED LED light tube. The GaN (gallium nitride) blue LED, GaP green LED and GaAs infrared LED, known as the two-element LED. Newer
processes, however, are four-element LEDs made from a four-element
AlGaInN material that mixes four elements, aluminum (Al), calcium (Ca),
indium (In), and nitrogen (N), that cover all visible light and some UV spectral range.
LED luminous intensity:
Luminous intensity measurement unit LED light-emitting diodes, LED
light-emitting diode knowledge of the unit of illumination (Lux Lux),
luminous flux unit (Lumen), luminous intensity units
(Candle power).
1CD
(Candlelight) refers to the fully radiating object, at the freezing
point of Platinum temperature, one-sixteenth of a square centimeter area
of luminous intensity. (Formerly
a whale candle with a diameter of 2.2 cm and a mass of 75.5 grams, 7.78
grams per hour and a flame height of 4.5 cm with luminous intensity in
the horizontal direction). 1L (lumens) refers to the luminous flux of 1 CD candle light illuminating at a distance of 1 cm in an area of 1 cm 2. 1Lux (lux) refers to the luminous flux of 1L evenly distributed over an area of 1 square meter of illumination.
General
active light emitting units using luminous intensity of candle CD, such
as incandescent, LED, etc .; reflection or penetrating objects using
luminous flux units lumens L, such as LCD projectors; and Lux units
Lux, generally used in photography and other fields . The three units of measure are numerically equivalent, but need to be understood from different perspectives. For
example, if an LCD projector has a brightness (luminous flux) of 1,600
lumens and its projection onto a total reflection screen is 60 inches (1
square meter), its illuminance is 1,600 lux. Assume that its light exit
from light source 1 Cm, the light exit area of 1 square centimeter, the light-emitting port of the luminous intensity of 1600CD. LED light-emitting diodes, LED light-emitting diode knowledge of
the real LCD projector due to the loss of light transmission, reflection
or translucent film loss and uneven light distribution, the brightness
will be greatly reduced, generally 50% efficiency is good.
In
actual use, the light intensity calculation often adopts the data unit
that is relatively easy to survey and mapping or changes to use. For
the LED display such active luminaries generally use CD / square meter
as the luminous intensity unit, and with the viewing angle as an
auxiliary parameter, which is equivalent to the surface of the screen
illumination unit lux; this value and screen effective display area Multiplied
to obtain the luminous intensity of the viewing angle of the entire
screen body. Assuming that the luminous intensity of each pixel in the
screen body is constant within the corresponding space of knowledge of
the LED light-emitting diode and the LED light-emitting diode, the value
can be considered as the whole screen body The luminous flux. General outdoor LED display to reach more than 4000CD / square meters of brightness can have a more ideal display in daylight. Ordinary indoor LED, larger brightness 700 ~ 2000 CD / square meters. The luminous intensity of a single LED is in CD.
2018-03-01
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