Light Emitting Diode TV
Organic and Inorganic
light-emitting diode (LED) television offers unrivaled
contrast. Both provide a more dynamic grayscale and
broader color volume than LCD television. The source
of light-emitting diode technology lies in the oldest
of solid-state technologies, the diode.
The Old Diode
OLED & IOLED descend from
the pioneer of solid-state electronic technology - the
diode. An early example is the 1906 crystal
radio. It used a diode crystal called a 'cat's
' to detect electromagnetic radio waves
(continuous electric sparks), induce an electric-magnetic
current, and modulate a crystal earphone that created
audible radio. This 'old diode' consisted of mineral
crystals such as galena -- lead crystal.
Another characteristic of the diode passes electric current
in one direction while blocking electric current in the
opposite direction. This one-way behavior is called
rectification. This trait is demonstrated by the rectifier
that converts alternating current to direct current in the
electrical product throughout our homes.
Diodes regulate voltage, protect circuits from surges,
detect and generate radio waves, produce light. Diodes
perform these functions by varying their materials and using
a technique of adding impurities called doping. The
diode materials include organic carbon-based silicon and
inorganic substances such as germanium.
Light from a diode, derived
from the phenomenon of 'electroluminescence', is an
electrical phenomenon in which a material emits light in
response to the passage of an electric current. Diodes
that produce light are the basis of OLED and IOLED TV.
OLED & IOLED TV
An OLED and IOLED television
screen is a solid-state electronic device.
An electroluminescent layered cell-plate or film situated
between anode and cathode electrodes.
The electrodes are a transparent front anode overlay and a
rear metallic cathode layer.
They and a transport layer sandwiched the electroluminescent
1. A hole-injection layer
2. A hole-transport layer
3. An emmisive layer.
4. an electron-transport negative layer.
Injected positive and negative electric charges recombine in
the emissive layer to produce electroluminescent
light. The brightness and color are enhanced by
'doping' the emissive layer with a small amount of highly
fluorescent molecules. The result offers a lower black
level, improved contrast, and a wider grayscale with more
accurate broader color volume than LCD TV.
OLED IOLED Difference
IOLED screens are inorganic
semiconducting crystal wafers made of gallium arsenide or
gallium nitride. OLED screens are organic crystal
wafers made of materials such as plastic or glass. Due to
lower thermal conductivity, an OLED emits less light than
IOLED. IOLED also has a longer illuminating life than
OLED. Yet OLED screens still have a life expectancy
that is similar to plasma and LCD technologies. The key
difference is cost. OLED is less expensive to produce
OLED Buzz Words
Manufacturers will attempt to
differentiate their LED based TVs from their
competitors. Therefore, prepare for an advertising
avalanche of video 'buzz words'.
Here is a shortlist of what you may confront.
Active Matrix OLED or AMOLED
uses a thin-film transistor (TFT) backplane to control each
sub-pixel of the display -- on/off or more/less light.
All OLED and IOLED televisions are active-matrix technology.
Super AMOLED / WOLED
WOLED, also referred to as
Super-AMOLED, pairs a fourth white sub-pixel with red,
green, and blue sub-pixels. The extra white sub-pixel
increases brightness. There are two versions of
AMOLED/WOLED. The first by LG OLED does not use side by side
red, green, and blue OLED sub-pixels. They stack
a red, a green, and a blue OLED to produce a single
sub-pixel. The RGB stack creates accurate white light.
LG then filters each white stack with a red, green, or blue
filter. A fourth remaining sub-pixel is left
unfiltered. A second discontinued Samsung version used
side by side red, green, blue, and white OLEDs. The LG
stacked-method cost much less to manufacture.
Changing LED Scene
LG WOLED technology has had
the lead in the OLED market place. But the LED race is
Samsung is reentering the LED race with modified OLED and
Samsung QD-OLED TV
Quantum Dot (QD) OLED
eliminates the LG color filtered RGB stacked OLED white
light concept. QD-OLED employs a blue OLED layer to
excite/illuminate red and green quantum dot film. Some
refer to this as color by blue. Red and green
sub-pixels are produced by the excited quantum dots.
Blue sub-pixels are produced by the blue OLED layer.
This method offers higher brightness, improved contrast, and
a broader volume of color.
Samsung Micro-LED TV (IOLED)
Samsung has also developed a
MicroLED TV. It uses a micrometer-sized inorganic LEDs
to produce individual red, green, blue IOLED sub-pixels.
This Samsung technology offers two key features.
Inorganic not organic LEDs.
2. It also eliminates color filters.
An inorganic LED offers longer life than an organic
LED. Eliminating filters increases brightness.
IOLED also avoids the possibility of screen burn-in. A
wall-sized commercial Micro-LED display is currently
A smaller retail-friendly size version is not yet
available. But Micro-LED may become a potential
alternative to home theater projection systems.
Samsung QNED TV
QNED TV is a quantum dot nanorod
LED TV. QNED as QD-OLED is a color-by-blue
display. But QNED replaces organic LEDs with inorganic
LEDs. As previously mentioned, inorganic LEDs are
brighter with longer illuminating life. QNED also cost
less to manufacture than Micro-LED TV. QNED should be
the first IOLED TV to reach retail floors in the 2nd quarter
Current publicity does not describe QNED as inorganic
LEDs. But published QNED Illustrations have listed GaN
(Gallium Nitride) as the essential component of the nanorod
LED. GaN crystal is an inorganic substance.