1.3.4 (g): describe the principles of operation of monitors and describe how they are applied to real life scenarios

Definition: A screen which displays an image generated by a computer

LCD
-Most monitors and TV's nowadays use Liquid Crystal Displays (LCD) technology.

In LCD's, the front layer of the screen is made up of liquid crystal diodes. These diodes are grouped in threes or fours, (known as pixels!)

The groups if three are: Red, Green and Blue
The groups of four are: Red, Green, Blue and Yellow. (This makes the colours more vivid)

Modern LCD monitors are back-lit using Light-Emitting Diode (LED) technology, which is designed to give the image better contrast and brightness.

Back then, LCD's used Cold-Cathode Fluorescent Lamp (CCDL) technology as the back lighting method.

Whats the difference between the way LCD's light up the screen and CCDL's light up the screen?

CCDL's use two fluorescent tubes behind the LCD screen, while LED's (LED technology) use a matrix of tiny LEDs behind the LCD screen.

Advantages of LEDs over CCFL's:

-LED's reach their max brightness faster than CCFL's do.
-LED's produce a white light, sharpening the image and make the colours look more vivid.
-LED's produce a brighter light, improving colour definition.
-LED's last much longer, making their use more reliable.
LED's are more efficient and use less energy, this mean they produce less heat.
-Monitors that use LED technology are much thinner than those which use CCFL technology.

OLED

We also see advancements in LED technology: we have Organic Light Emitting Diode (OLED) technology.

-These make use of organic materials, made up of carbon compounds, to create flexible semi-conductors.

-Organic films are placed in between two charged electrodes (a metallic cathode and a glass anode)

-When an electric field is applied to the electrodes. They emit light! This means no backlighting is required, allowing for very thin screens.

-OLED is a self contained system, which means that there is no need for LCD technology.

-OLED allows screens to be curved, since they are flexible. This ensures a good picture from any angle.

-Due to its flexibility and thinness, OLED screens can be bent into any shape. If this is applied to mobile phones, you can fold your phone and put it in your pocket or wrap it around your wrist!

Advantages of OLED's over LCD/LED's:

- OLED screens are thinner, lighter and more flexible.
-OLED layers can be made of plastic rather than glass, which means they can be made into large, thin sheets.
-OLED's give a brighter light.
-OLED's have a large field of view (around 170°), making them ideal for TV's and advertising.