A Brief overview of Display Technologies

Technology that acquires stores and produces bright, clear and high resolution images for visual or tactile presentation is called display technology. Display technology has been going through phenomenal development over the last decade or so. Few years back, there was only Cathode Ray Tube (CRT) technology that dominated the display scene. But today, there are host of other display technologies like Plasma Display Panel (PDP), Digital Light Processing (DLP), Liquid Crystal Display (LCD) etc. and use of them vary from product to product and manufacturer to manufacturer. Also, many other new technologies are trying to emerge out of research laboratories and gain a share of the large display technology market.

In Cathode Ray Tube (CRT) technology, the light occurs when an electron beam stimulates a phosphor. It generates symbols on the display tube by guiding the electron beam over a path that forms the character. In CRT, two electron guns (writing gun and flooding gun) are used to generate display.

In Plasma Display Panel (PDP), panels are made of glass layers separated by thin layers of neon-based gas. One horizontal and one vertical conductor are put on panels and when a voltage is applied across the intersection of these conductors, the gas at the intersection becomes ionized and emits a spot of light. The sustained and high frequency voltage keeps the spot constantly illuminated and glowing.

Liquid Crystal Display (LCD is a display technology, where special liquid crystals are sandwiched between polarizing transparent layers of glass. Liquid crystal cells, when charged by electric transistors change the reflectivity in the applied electric fields and then display color or monochrome pixels. The Digital Light Processing (DLP) uses a Digital Micro mirror Device (DMD) chip with 400,000 to more than 2,000,000 light switches that cancel or reflect light. The process turns image data into light and is capable of projecting sharp, clear images without loosing original image resolution.

As we see, different technologies may have many different characteristics. It remains up to the end user to decide upon which one suits his needs and budget.