LED and Plasma are two technologies for volatile display of high quality pictures. LED displays work on liquid crystal or semiconductor technology while plasma displays work on ionized gasses.
More about LED
LED stands for Light Emitting Diode and two types of display devices are manufactured with LEDs. Discrete LEDs can be used to create large flat screen displays, in which a cluster of Red, Green, and Blue LEDs combine to act as pixels. Such displays are known as LED panels, which are large and are used for outdoor purposes. The other is the LCD displays backlit with LEDs.
LCD stands for Liquid Crystal Display, which is a flat panel display developed using the light modulating property of the liquid crystals. The liquid crystal is considered to be a state of matter, where the material has both liquid like and crystal like properties. Liquid crystals have the ability to reorient the light, but not to emit light. This property is used to control the light passing through two polarizers, where the liquid crystals are controlled using an electric field. Liquid crystals act as valves for the light rays either blocking or reorienting and allowing them to pass. A backlight or a reflector is the component which directs light to the polarizers. Normal LCDs use Cold Cathode Fluorescent Lights (CCFL) for the back light while, in LED displays, an LED backlight is used.
The LED backlit displays have properties inherent from LCD displays and power consumption is even less due to the low power used by the LEDs. The display is also slimmer than the LCD displays. They have a greater color range, better contrast and brightness. They produce a more accurate image rendering, and the response time is higher. The black level of the display is also higher, and the LEDs are relatively expensive.
More about Plasma
Plasma displays work based on energy released by ionized gases. Noble gases and a small amount of mercury are included in small cells coated with phosphorous material. When an electric field is applied, the gasses turn into plasma, and the subsequent process illuminates the phosphor. The same principle is behind the fluorescent light. A plasma screen is an array of miniscule chambers called cells aligned within two layers of glass. In simple, a plasma display is a collection of millions of small florescent bulbs.
The main advantage of plasma displays is the high contrast ratio due to the low blackness conditions offered by the cells. Color saturation or contrast distortions are negligible, while no geometric distortions occur in plasma displays. The response time is also greater than the other volatile displays.
However, the high operating temperature due to plasma conditions results in high energy consumption and more heat generation; therefore less energy efficient. The size of the cells limits the resolution available, and which also limits the size. Plasma displays are produced to much larger scales, to accommodate this limitation. The pressure difference between the screen glass and the gas in the cells affect the performance of the screen. At higher altitude, the performance deteriorates due to low pressure conditions
LED vs Plasma
• LEDs consume less power; therefore, more energy efficient, while plasma displays operate at higher temperature; therefore, generate more heat and less energy efficient.
• Plasma displays offer better contrast ratio and has a better response time.
• Plasma displays have better blackness conditions
• Plasma displays are heavier and bulkier, while LED displays tend to be slimmer and less heavy.
• Plasma screens are fragile due to the glass structure of the screen.
• Image flicker occurs in the plasma while, LCDs have no image flicker.
• Pressure difference affects the operation of the Plasma screens while LED displays have much less effect.