Search results
Results from the WOW.Com Content Network
An overhead projector works on the same principle as a slide projector, in which a focusing lens projects light from an illuminated slide onto a projection screen where a real image is formed. However some differences are necessitated by the much larger size of the transparencies used (generally the size of a printed page), and the requirement ...
A projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen. Most projectors create an image by shining a light through a small transparent lens , but some newer types of projectors can project the image directly, by using lasers .
Overhead projector in operation, with a transparency being flashed A transparency , also known variously as a viewfoil or foil (from the French word "feuille" or sheet), or viewgraph , is a thin sheet of transparent flexible material, typically polyester (historically cellulose acetate ), onto which figures can be drawn.
A simple example is an overhead projector transparency. Usually when the term SLM is used, it means that the transparency can be controlled by a computer. SLMs are primarily marketed for image projection, displays devices, [1] and maskless lithography. [citation needed] SLMs are also used in optical computing and holographic optical tweezers.
It works with an overhead projector. 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 input, and sometimes Composite (RCA) and S-Video input. Later models have remotes, with functions such as 'freeze ...
Square-shaped screens used for overhead projectors sometimes double as projection screens for digital projectors in meeting rooms, where space is scarce and multiple screens can seem redundant. These screens have an aspect ratio of 1:1 by definition. Most image sources are designed to project a perfectly rectangular image on a flat screen. If ...
The opaque projector, or episcope is a device which displays opaque materials by shining a bright lamp onto the object from above. The episcope must be distinguished from the diascope , which is a projector used for projecting images of transparent objects (such as films), and from the epidiascope , which is capable of projecting images of both ...
It is a modern equivalent of the slide projector or overhead projector. To display images, LCD (liquid-crystal display) projectors typically send light from a metal-halide lamp through a prism or series of dichroic filters that separates light to three polysilicon panels – one each for the red, green and blue components of the video signal ...