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Polaroid is the name of a type of synthetic plastic sheet which is used to polarise light. For other uses, see Plastic (disambiguation). ...
In electrodynamics, polarization (also spelled polarisation) is the property of electromagnetic waves, such as light, that describes the direction of their transverse electric field. ...
The original material, patented in 1929 (U.S. Patent 1,918,848 ) and further developed in 1932 by Edwin H. Land, consists of many microscopic crystals of iodoquinine sulphate (herapathite) embedded in a transparent nitrocellulose polymer film. The needle-like crystals are aligned during manufacture of the film by stretching or by applying electric or magnetic fields. With the crystals aligned, the sheet is dichroic: it tends to absorb light which is polarised parallel to the direction of the crystal alignment, but transmits light which is polarised perpendicular to it. The resultant electric field of an electromagnetic wave (such as light) determines its polarisation. If the wave interacts with a line of crystals as in a sheet of polaroid, any varying electric field in the direction parallel to the line of the crystals will cause a current to flow along this line. The electrons moving in this current will collide with other particles and re-emit the light backwards and forwards. This will cancel the incident wave causing little or no transmission through the sheet. The component of the electric field perpendicular to the line of crystals however can cause only small movements in the electrons as they can't move very much from side to side. This means there will be little change in the perpendicular component of the field leading to transmission of the part of the light wave polarized perpendicular to the crystals only, hence allowing the material to be used as a light polariser. Year 1929 (MCMXXIX) was a common year starting on Tuesday (link will display the full calendar) of the Gregorian calendar. ...
Year 1932 (MCMXXXII) was a leap year starting on Friday (the link will display full 1932 calendar) of the Gregorian calendar. ...
Edwin Herbert Land Edwin Herbert Land (May 12, 1909 – March 1, 1991) was an American scientist and inventor. ...
For other uses, see Crystal (disambiguation). ...
Quinine (IPA: ) is a natural white crystalline alkaloid having antipyretic (fever-reducing), antimalarial, analgesic (painkilling), and anti-inflammatory properties and a bitter taste. ...
Herapathite, or iodoquinine sulphate, is a compound whose crystals are dichroic and thus can be used for polarizing light. ...
Skeletal formula of nitrocellulose Ball-and-stick model of a section of nitrocellulose Nitrocellulose (also: cellulose nitrate, flash paper) is a highly flammable compound formed by nitrating cellulose through, for example, exposure to nitric acid or another powerful nitrating agent. ...
A polymer (from Greek: πολυ, polu, many; and μÎÏος, meros, part) is a substance composed of molecules with large molecular mass composed of repeating structural units, or monomers, connected by covalent chemical bonds. ...
In optics, the term dichroic has two related but distinct meanings. ...
A polarizer is a device that converts an unpolarized or mixed-polarization beam of electromagnetic waves (e. ...
A building seen through polaroid sunglasses 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. Image File history File linksMetadata Download high resolution version (1229x922, 410 KB) Summary A building seen through polaroid sunglasses. ...
Image File history File linksMetadata Download high resolution version (1229x922, 410 KB) Summary A building seen through polaroid sunglasses. ...
Year 1938 (MCMXXXVIII) was a common year starting on Saturday (link will take you to calendar). ...
Chemical structure of polyvinyl alcohol Polyvinyl alcohol (PVOH, PVA, or PVAL) is a water-soluble synthetic polymer. ...
For the record label, see Iodine Recordings. ...
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 displays, optical microscopes and sunglasses. LCD redirects here. ...
Robert Hookes microscope (1665) - an engineered device used to study living systems. ...
Ray-Ban Wayfarer sunglasses (RB2132 901L) Sunglasses are a visual aid, variously termed spectacles or glasses, which feature lenses that are coloured or darkened to prevent strong light from reaching the eyes. ...
The intensity of light passing through a Polaroid polariser is described by Malus's law. A polarizer is a device that converts an unpolarized or mixed-polarization beam of electromagnetic waves (e. ...
Polaroid is also used as a trade name for a variety of products sold by licensees of the Polaroid Corporation, including consumer electronics, sunglasses based on Polaroid polarisers, and instant-print photographic film and cameras. Polaroid Corporation was founded in 1937 by Edwin H. Land. ...
See also In electrodynamics, polarization (also spelled polarisation) is the property of electromagnetic waves, such as light, that describes the direction of their transverse electric field. ...
Edwin Herbert Land Edwin Herbert Land (May 12, 1909 – March 1, 1991) was an American scientist and inventor. ...
Polaroid Corporation was founded in 1937 by Edwin H. Land. ...
An instant camera is a type of camera with self-developing film. ...
Instant film is a photographic film that is designed to be used in an instant camera. ...
List of digital camera brands past and present, updated to 2005, but may miss some. ...
In film, the term 3-D (or 3D) is used to describe any visual presentation system that attempts to maintain or recreate moving images of the third dimension, the illusion of depth as seen by the viewer. ...
References - Land, E.H. (1951). "Some aspects on the development of sheet polarizers". J. Optical Society of America 41 (12), 957-963.
- Halliday, Resnick, Walker. "Fundamentals of Physics" 7th edition. John Wiley & Sons, Inc.
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