Sunday, July 26, 2009

Projectors


There are various types of projectors. Slide projector, overhead projector (variant of slide projector), CRT projector (uses cathode ray tubes), LCD projector (uses LCD light gates), DLP projector (uses Texas Instruments’ DLP technology), LCOS projector (uses liquid crystal on silicon), D-ILA Projector (uses Direct-drive Image Light Amplifier based on LCOS technology.), LED projectors (uses an array of Light Emitting Diodes as the light source).


LCD projector is used for displaying video, images or computer data on a screen or other flat surface. Often, projection screen is used. It is a modern analog of the slide projector or overhead projector.

Newer technologies, such as DLP (Digital Light Processing) and LCOS are becoming more popular in video projection. These projectors are light-weight, can be connected to many different devices and have powerful projection ability.

LCD projectors project images by shining light through transparent LCD cells.

DLP projector projects images by reflecting lights against hundreds-of-thousands of tiny mirrors called digital micro-mirror devices (DMDs). Each mirror reflects one pixel in the resolution of the projected image. Thus, pixel-to-pixel relationship ensures superior quality picture. Here, instead of passing light source through a liquid crystal cells like LCD projector, light is reflected off the panels called DMDs. Thus, it is ‘reflective’ technology.

In another word, the DMD chip, also known as an optical semiconductor, contains a rectangular array of hundreds-of-thousands of tiny actuated microscopic mirrors. These mirrors can reflect an all-digital image onto a screen or other surface in coordination with graphic signal, light source and projection lens.

LCOS combines the LCD and DLP technologies. It is a reflective technology that uses liquid crystals instead of individual mirrors.

The model shown above is HS102G of LG Company. The approximate cost in Indian Rupees is Rs. 60,000/-.

More information on: http://www.in.lge.com/