A Projection panel (also called ''overhead display'' or ''LCD panel''
) is a device that, although no longer in production, was used as a
data projector
A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. Video projectors use a very bright ultra-high-performance lamp (a special mercury arc lamp), Xen ...
is today.
It works with an
overhead projector
An overhead projector (often abbreviated to OHP), like a film or slide projector, uses light to project an enlarged image on a screen, allowing the view of a small document or picture to be shared with a large audience.
In the overhead project ...
. The panel consists of a translucent
LCD, and a fan to keep it cool. The projection panel sits on the bed of the overhead projector, and acts like a piece of
transparency. The panels have a
VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the PC industry within three years. The term can no ...
input, and sometimes
Composite (RCA) and
S-Video
S-Video (also known as separate video, Y/C, and erroneously Super-Video ) is an analog video signal format that carries standard-definition video, typically at 525 lines or 625 lines. It encodes video luma and chrominance on two separate channe ...
input. Later models have remotes, with functions such as 'freeze' which lets you freeze the image, useful for when you want to leave something on the screen whilst you do other things. Earlier models only had 640x480 resolution, while newer ones had up to
SVGA
Super VGA (SVGA) is a broad term that covers a wide range of computer display standards that extended IBM's VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the I ...
resolution. Proxima, one maker of the panels, included a
magic wand
A wand is a thin, light-weight rod that is held with one hand, and is traditionally made of wood, but may also be made of other materials, such as metal or plastic.
Long versions of wands are often styled in forms of staves or sceptres, which c ...
and sensor, which worked with the sensor detecting where you put the wand, to create and interactive effect, the equivalent of today's
smart board
Smart Technologies (stylized as SMART Technologies) also known as Smart, is a Canadian company headquartered in Calgary, Alberta, Canada and wholly owned by Foxconn. Founded in 1987, Smart is best known as the developer of interactive whiteboar ...
s.
Although they are not produced anymore, used panels can be purchased for a fraction of the price of a data projector. The panels are quite dim, as they do not let a great deal of light through, so brightness can be a problem, even with a powerful overhead projector.
References
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Display technology