LED TVs come in various types yet they have
the same nature of original LCD TV with CCFL lamp.
The term “LED TV” has been popular in many
stores but it is a mistake when consider LED TV as LED panel in stadiums or
advertising boards. Those LED panels is created by a ton of LED bulbs in a wide
range of colors, helping reproduce image for viewers.
LED
TV always needs light for its display
LED TV is, in fact, a kind of LCD TV yet
its lighting system is formed of LED bulbs. To display images, LCD screen
always need lighting. Since the 1970s, LCD screen has been commercialized and
appeared in digital watches. The name LCD came from that slight layers made of
metal and materials were kept as if they were in a sandwich.
In early times, monochrome LCD had been
used for a long time before color LCD having the same structure was applied. In
order to display, all TVs need a light source illuminating all LCD layers. The
difference of many lighting techniques makes different LCD technologies.
The
difference between two LCD screen: CCFL and LED backlights
CCFL and LED are most popular backlighting
in LCD TVs. Traditional LCD screens use neon lights arranged according to
width. Through times, these neon lights have been improved to be slighter with polarizer
layers for better performance.
Meanwhile, today’s popular LED backlighting
has been applied on TV since 2004 when Sony introduced their Wega TV. The idea
at the time bore similarity to today’s one though there was a little difference
that they used spherical LED bulbs.
Regarding LED backlighting, there are 2
types: backlit ad edge-lit. Backlit LCD screen has superior advantages which are
enhancing contrast and local dimming so that display images come in realer
blacks and depths.
On the other hand, Edge-lit LED screen has
slimmer design because LED bulbs are not supposed to be right under the panel. Some
hi-end edge-lit monitor also support local dimming though they appear far less
efficient than backlit ones.
LED
lights are put above and beneath the panel
There’s another classification: white LED
and RGB LED. White LED is similar to CCFL with a green lighting source though it
is also covered in a surfer layer in order to produce white lighting. This results
in that TV is likely to display greens better than blues and reds.
From another view, RGB LED has greater
gamut when using all three red, blue and green blubs. This type of LED
theoretically delivers better display with more vivid and accurate colors. In
fact, its complex structure makes RGB LED less popular and the last RBG LED
model on the market was Sharp LC-65XS1M TV in 2009.
Sharp
LC-65XS1M TV
Aside from backlit LED, edge-lit LED is
more common. It is formed by 2 main components including a line of LED bulbs alongside
the upper/lower edges and a thin plastic layer in charge of transmitting the
lighting. Thanks to this collaboration, lighting is equally distributed to
every dots of the screen so as to produce images. Naturally, edge-lit LED lack a
system controlling backlights thus its visual quality can’t compete with that
of backlit LED.
Several years ago, people have dreamt about
LED TV due to its high cost and few models. However, at present, manufacturers
have been replacing traditional LCDs with LEDs. Users now find difficulty looking
for a 40inch-and-above LCD model yet it’s very easy to pick a LED one which
comes in various sizes: 24, 26, 32, 40, 46, 60 or 65 inch.
Besides, LED TV’s price is reducing to
compete with LCD TV. Difference in prices between LED and LCD models is not so
considerable when it becomes few tens of dollars instead of $225 at previous
time (considered models are 32 inches and 40 inches).
