Display Devices in Computer Graphics
The most prominent part of a personal computer is the display system that is responsible for graphics display. The display system may be attached to a PC to display character, picture, and video output. The display systems are often referred to as Video Display Unit (VDU) or Monitors.
Types of Display Devices in Computer Graphics:
There are mainly six types of display devices in computer graphics.
- Cathode-Ray Tube(CRT)
- Liquid Crystal Display (LCD)
- Thin Film Transistor (TFT)
- Light Emitting Diode (LED)
- Direct View Storage Tubes (DVST)
- Plasma Display
Cathode Ray Tube (CRT):
A CRT is like a big vacuum glass bottle. It contains three electron guns that squirt out a focused beam of electrons, a deflection electrostatic which deflects the beams both up and down and side-wise, and a phosphor-coated screen upon which these beams are.
The primary component is an electron gun a cathode (negatively charged) encapsulated by a metal cylinder that is called the Control grid. A heating element inside the cathode causes the cathode to be heated up as the current is passed. As a result, electrons boil off from the hot cathode surface. These electrons are accelerated towards the CRT screen by a high positive voltage applied near the screen that is called Anode.
Liquid Crystal Display (LCD):
liquid crystal display (LCD) is a thin, flat display device made up of any number of pixels arrayed in front of a light source or reflector. LCD Colour displays are possible by incorporating color filters. The heart of all LCDs is a liquid crystal itself. A liquid crystal is a substance that flows like a liquid, but its molecules orient themselves in the manner of a crystal. It uses very small amounts of electric power and is suitable for use in battery-powered electronic devices.
Thin Film Transistor (TFT):
Thin film transistor (TFT) is a special kind of field effect transistor made by depositing thin films for the metallic contacts, semiconductor active layer, and dielectric layer. It is a variant of liquid crystal display (LCD) that uses thin film transistor (TFT) technology to improve image quality. TFT LCD is one type of active matrix LCD, It is usually synonymous with LCD. TFT is mainly used in both flat-panel displays and projectors.
Light Emitting Diode (LED):
LED is a semiconductor device that emits when current passes through it. The size of the LED is small, so we can easily make any display unit by arranging a large number of LEDs. It consumes more power compared to LCD. LED is mainly used on TV, smartphones, traffic light, etc.
Direct View Storage Tubes (DVST):
A cathode-ray tube in which secondary emission of electrons from a storage grid is used to provide an intensely bright display for long and controllable periods of time that is Also known as Direct View Storage Tubes (DVST).
A plasma display is a type of flat panel display that uses tiny plasma cells. It is also known as the Gas Discharge Display. The main components of the plasma display are given as follows:
Anode: It is used to deliver a positive voltage. It has line wires.
Cathode: It is used to provide negative voltage to gas cells. It also has fine wires.
Gas Plates: These plates work as capacitors. When we pass the voltage, the cell lights regularly.
Fluorescent cells: It contains small pockets of gas liquids when the voltage is passed to this neon gas.