1. R.K.UNIVERSITY
SCHOOL OF DIPLOMA STUDIES

2.  The LED TV is a more advanced version of the
LCD TV. While both types of TV on LCD
technology and have flat-panel designs.
 "LED TVs are slimmer, brighter, and more
detailed than your traditional LCD TV." LED TVs
function by illuminating LCD panels with LED
backlighting. However, not all LED TVs utilize
the same type of LED backlighting.

3.  A LCD screen is composed of 2 parts, the actual
liquid crystal display and a light source at the
back of the screen (called backlight). A light
diffuser is placed between the backlight and the
LCD screen to uniform the source of light equally
across the screen.

4. There are 2 main types of backlights used
in LCD screens.
1. CCFL
2. LED

5. LCD stands for Liquid Crystal Display. An
LCD TV has liquid crystal between the
display panel of the TV, which gets
activated when an electric current is
supplied to it.

6.  When someone refers to a LCD TV, he usually refers
to a CCFL (cold-cathode fluorescent lamps)
backlighted LCD screen. This is how a normal LCD
screen works. The backlight is a series of light tubes
placed behind the screen. These tubes are very
similar to the fluorescent lamp used almost
everywhere, but smaller.

7. It is important to note that…
LCD chips and pixels do not produce their
own light. In order for an LCD television to
produce a visible image on a TV screen
the LCD's pixels have to be "backlight“.

8. LCDs with CCFL backlight are on their
way out of the market. Manufacturers are
now only producing them for their lower
end and smaller models. They are getting
replaced by LED TVs. They have the same
screen but have LED lights instead of a
CCFL tube for the backlight

9. LCD stands for “liquid crystal display” and
technically, both LED and LCD TVs are
liquid crystal displays.
The basic technology is the same in that
both television types have two layers of
polarized glass through which the liquid
crystals both block and pass light.
So really, LED TVs are a subset of LCD TVs.

10. LED, which stands for “light emitting
diodes,” differs from general LCD TVs in
that LCDs use fluorescent lights while LEDs
use those light emitting diodes.
Also, the placement of the lights on an LED
TV can different.
The fluorescent lights in an LCD TV are
always behind the screen.
But, On an LED TV, the light emitting
diodes can be placed either behind the
screen or around its edges.

11.  The difference in lights and in lighting
placement has generally meant that LED TVs
can be thinner than LCDs, although this is
starting to change.
 It has also meant that LED TVs run with
greater energy efficiency and can provide a
clearer, better picture than the general LCD
TVs.
 Because of difference in lights and lightning
placement there are two types
1. EDGE LIT
2. FULL ARRAY LIT

12. This is the most common method for LED
TVs.

13. In an edge lit LED screen, the LEDs are
placed at the peripheral of the screen.
Depending on the television, it can be all
around the screen or only on the sides or
the bottom.
This allows the screen to be very thin.
However, it can cause some spots on the
screen to be brighter than others, like the
edges.

14. This method is considered the best LED
backlight type, but can only be found on a
very limited number of models.
In a full array LED screen, the LEDs are
distributed evenly behind the entire
screen. This produces a more uniform
backlight and it provides a more effective
use of local dimming, where it can change
the luminosity of only a specific part of the
screen.

16.  A LED screen as normally referred is actually a LCD
screen, but instead of having a normal CCFL backlight,
it uses light-emitting diodes (LEDs) as a source of light
behind the screen.
 A LED is more energy efficient and a lot smaller than a
CCFL, enabling a thinner television screen.
 Marketing made a lot of fuss about LED TVs, but it is
only the backlight is changing, so there is actually no
picture quality improvement over a normal LCD
screen. It is more of a natural improvement instead of
a game changer. It is still a better backlight, so
manufacturers are putting it on their best LCD panels,
making it worth the upgrade.

17. Thank You
VIRENDRASINH VAGHELA
11SDSEC01018