Multimedia Production

MULTIMEDIA PRODUCTION 4(1+3)

Lesson 16: LCD (Liquid Crystal Display) Panel / Projectors)

History

• Early LCD systems were used with existing overhead projectors. The LCD system did not have a light source of its own: it was built on a large "plate" that sat on top of the projector in place of the transparencies.
• The LCD projector was invented by New York inventor Gene Dolgoff. He began working on it in 1968 as a way to produce a video projector that would be brighter than the then-available 3-CRT projectors.
• The idea was to use an element referred to as a "light valve" to regulate the amount of light that passes through it which would allow the use of a very powerful external light source.
• A light valve (LV) is a device for varying the quantity of light, from a source, which reaches a target like computer screen surfaces or a wall screen in the case of a light projector.
• After trying many different materials, he settled on liquid crystals to modulate the light in 1971. It took him until 1984 to get an addressable liquid crystal display (LCD), which is when he built the world's first LCD projector.
• After building it, he saw many problems that had to be corrected including major light losses and very noticeable pixels. He then invented new optical methods to create a high efficiency and high-brightness projector and invented depixelization to eliminate the appearance of the pixels.
• With patents all around the world, he started Project vision; Inc. in 1988, the world's first LCD projector company, later licensed the technology to other companies such as Panasonic and Samsung.