LCD vs Plasma
LCD and Plasma are two of the volatile display technologies used in display devices for high quality pictures. As the name implies, LCDs work on liquid crystals, and plasma displays work on electrically charged (ionized gasses). Both technologies are used in HDTVs.
More about LCD
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. Cold Cathode Fluorescent Lights (CCFL) are used in television displays.
LCDs are found in almost all areas of modern technology due to its compactness and the energy efficiency. It consumes 60% less power than CRT displays. Since the display is flat, no geometric disorientation occurs. Therefore, LCDs are ideal for high quality displays. Theoretically, LCD technology offers no barriers for the resolution and the displays can be made to any size. LCD TVs and Monitors are just two applications of the technology. These devices are relatively cheaper.
Shortcomings of LCDs are their low view angle and low response time. The contrast and the color might vary from one angle to another, and sometimes brightness distortions occur at the edges. Sometimes the ghost effects are created for fast moving images, due to slow response and tend to deteriorate at low temperatures.
More about Plasma Displays
Plasma displays work based on energy released by ionized gases. Noble gases and a small amount of mercury are included in small cell coated with phosphor 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 trapped within two layers of glass.
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 result in high energy consumption and more heat generation; therefore, less energy efficient. The size of the cells limits the resolution available which also limit 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.
LCD vs Plasma
• Plasma displays have higher contrast ratio and better color
• Plasma displays operate at much higher temperatures
• LCDs consume less power and produce less heat; therefore, more energy efficient, while plasma displays rely on higher temperature for operation and less energy efficient
• LCDs have a lower viewing angle, but plasma displays have a much higher viewing angle
• Plasma displays have lower response time than the LCDs
• Plasma displays are heavier and bulky while LCDs are less heavy and slimmer.
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