How tv works?
How television works?
Eager about knowing the technology behind working on
television
Basically tele-vision, tele means far vision means
seeing finally able to watch something that is happening around at our own
convenient place.
Television is the most time-pass setup for us. Through television, you are to able to watch
news, sports, movies, entertainment shows and more.
Have you ever wanted to know the technology behind the
television?
Basically the image is formed by pixels and the images
are displayed at the rate the eyes cannot detect the change is happening and it
appears to be like a video.
The image on the screen of the television is displayed
using a tube called
Cathode Ray Tube (CRT).
The television used in olden days contains a cathode
ray tube to display images. Today the technologies used in our Tv ’s are LCD, LED
and plasma.
Coming to the cathode ray tube based television. In a
cathode ray tube the cathode is a heated filament. The heated film is placed in
Glass tube vacuum.
The cathode releases electrons and this poured off
electrons are attracted by anode terminal. These series of charged particles
are focused on to the specific points on the wider tube. These charged
particles emit light when they hit the Phosphorus screen. The ion gun sprays the images onto the screen.
Different kind of phosphorus emits different colors, in
fact, only three colors are needed and rest of the colors are formed from these
three primary colors. As the energy travels from the cathode to anode it is filtered
to hit the exact point on the screen.
Plasma televisions
Plasma television consists of small cells that are
filled with neon and xenon gases. Each cell is connected to the electrode, when
heated, gases contained in the cell excites. These gases emits charged
particles and these charged particle interacts with the phosphorus contained in
the same cell. When charged particles interact with the phosphorous light is
emitted. Different phosphorous coatings emit different colors. The pixels of
the image depends upon the number of cells contained in the cell if there are
more cells then it leads to clear images.
Liquid Crystal Displays (LCD)
Basically Liquid crystal displays contains two parts
the display and the light source at the back of the screen called as backlight.
A light diffuser is present between the
screen and the light source (backlight) it uniforms the light equally on the
screen.
The liquid crystal display acts as a filter to block
the light on a pixel per basis. The opacity can be controlled by the electric
field applied to it. For example if the screen wants to display the black then
the light is completely blocked to display the black color.
There are two types of Liquid Crystal Display screens
1. CCFL
2. LED’s
Cold Cathode Fluorescent Lamps (CCFL)
This CCFL LCD televisions are commonly referred to as backlit
LCD screens.
The series of light tubes are present behind the screen
known as backlight and are similar to fluorescent lamps.
LED
The difference between LED and LCD is the source of
backlight in LCD the backlight source is CCFL whereas in Led televisions the
source of backlight is provided by light emitting diodes (LED)
And there are three types of arrangements in led as
backlight source
They are
1.
Full array type LED arrangement
This is the best led type I
can say because the light emitting diodes are evenly distributed all over the
screen by this arrangement the backlight is uniform.
2.
Edge Lit type LED arrangement
In Edge Lit Led televisions
the led are placed at the edges of the screen and the placing of led depends on
the television for some televisions the led are placed all around the screen or
only on the sides or at the bottom of the screen.
3.
Direct lit Led arrangement
It is almost similar to
the full array arrangement, but the only difference is the number of Light
emitting diodes used to display the image. In this case the number of light emitting
diodes is less compared to the full array arrangement and the led’s are placed behind
the screen.
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