Information AboutPolaroid |
| CATEGORIES ABOUT POLAROID | |
| optics | |
| polarization | |
| brand name materials | |
| photography equipment | |
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Polaroid (a Trademark of the Polaroid Corporation ) is the name of a type of synthetic Plastic sheet which is used to Polarise light. The original material, patented in . This material, known as ''J-sheet'', was later replaced by the improved ''H-sheet'' Polaroid, invented in 1938 by Land. H-sheet is a Polyvinyl Alcohol (PVA) polymer impregnated with Iodine . During manufacture, the PVA polymer chains are stretched such that they form an array of aligned, linear molecules in the material. The iodine dopant attaches to the PVA molecules and makes them conducting along the length of the chains. Light polarised parallel to the chains is absorbed, and light polarised perpendicular to the chains is transmitted. Another type of Polaroid is the ''K-sheet'' polariser, which consists of aligned Polyvinylene chains. This polariser material is particularly resistant to humidity and heat. Polaroid sheets are used in Liquid Crystal Display s, Optical Microscope s and Sunglasses . Polaroid is also used as a trade name for a variety of products sold by the Polaroid Corporation , including sunglasses based on Polaroid polarisers, and instant-print photographic film and cameras. SEE ALSO
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