LCD Projector’s History

The LCD projector was invented by New York inventor Gene Dolgoff. He began working on it in college 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. This would allow the use of a very powerful external light source. 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 Projectavision, Inc. in 1988, the world’s first LCD projector company, which he took public on Nasdaq in 1990. He licensed the technology to other companies such as Panasonic and Samsung. This technology and company started the digital projection industry. In 1989 he was awarded the first Darpa contract ($1 million) for proposing that the US HDTV standard should use digital processing and projection. As a member of the National Association of Photographic Manufacturers (NAPM) Standards Subcommittee, IT7-3, he along with Leon Shapiro, co-developed the worldwide ANSI standard for measurement of brightness, contrast, and resolution of electronic projectors.

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. This provided a stop-gap solution in the era when the computer was not yet the universal display medium, creating a market for LCD projectors before their current main use became popular.

This technology is employed in some sizes of rear projection television consoles, as there are cost advantages when employed in mid size sets (40 to 50 inch diagonal). This is not expected to have much longevity in the “home theater” marketplace due to expected improvements cost/performance of competing technologies, particularly in direct-view LCD panels at the lower range of sizes and DLP projection in the larger sizes.

In 2004 and 2005, LCD front projection has been enjoying a come-back because of the addition of the dynamic iris which has improved perceived contrast up to the levels of DLP.

The basic design of an LCD projector is frequently used by hobbyists who build their own DIY projection systems. The basic technique is to combine a high CRI HID lamp and ballast with a condenser and collector fresnel, an LCD removed from a common computer display and a triplet.

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