Light Emitting Diode TV
Organic and Inorganic
light-emitting diode (LED) based television offers unrivaled
contrast. They 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, plus 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
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. They
consist of 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. The anode/cathode layers
sandwich the electroluminescent cell.
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 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. The COVID lock down has
stalled its release. Look for OD-OLED TV in the near
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 should be
the first IOLED TV to reach retail floors. Look for
QNED release sometime in 2022.
Current publicity does not describe Samsung 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
LG QNED LCD TV Label Confusion
LG introduced a QNED LCD TV. This may be a good LCD
TV, but it is not an IOLED TV. It is a mini LED
full-array quantum dot color filtered backlit LCD TV.
Samsung Micro-LED TV (IOLED)
Samsung has developed a
MicroLED TV. It uses a micrometer-sized inorganic
LEDs to produce individual red, green, blue IOLED
sub-pixels. However, the Micro-LED is only available
in a wall-size 110 inch, a 99 inch, 88 inch, and 76 inch
model. Micro-LED may become a potential alternative
to home theater projection systems.