3m Innovative Properties Company

Polaroid Corporation

John J Cael

Babu Nana Gaddam

Steven M Heilmann

Duane Douglas Fansler

Robert T Fitzsimons, Jr

Todd D Jones

Philip J Ralli

Giorgio B Trapani

Robert L Jones

Philip Edwin Watson

Hassan Sahouani

Kim Marie Vogel

Pradnya V Nagarkar

Tung-Feng Yeh

William K Smyth

Rong-Chang Liang

Giorgio Trapani

James N Gordon

Stewart Bennett

Jason W Balich

John C Branca

Narendra S Kadaba

William Pugh

David M Foresyth

Atsushi Suzuki

A polarizer is used with a liquid crystal display (LCD) cell whose liquid crystal molecules are switched in the plane of the cell. The LCD has birefringent properties that are different from other types of LCD cell and, unlike other types of LCD, the image contrast is maintained and there is little color shift in the dark state when a low birefringence polarizer is used with the SIP LCD cell. In one embodiment, the x-z retardation of the layers between the polarization-sensitive absorbing layer and the LCD is less than 20 nm. In another embodiment, the x-z birefringence is less than 0.0005. The low levels of retardation and birefringence may be achieved by omitting the commonly used cellulose triacetate layer between the polarization-sensitive absorbing layer and the LCD.

Liquid crystal display with neutral dark state

A process for preparing a polarizer is described whereby an article comprising an oriented, vinylalcohol polymer film layer, and an acid donor layer comprising a photoacid generator, is exposed to radiant energy at a temperature sufficient to effect a partial dehydration of the vinylalcohol polymer to a vinylalcohol/poly(acetylene) copolymer.

Process for preparing a K-type polarizer

An enhanced K-type polarizer includes a molecularly oriented sheet of polyvinylalcohol/polyvinylene block copolymer material having polyvinylene blocks formed by molecular dehydration of a sheet of polyvinylalcohol wherein the molecularly oriented sheet comprises light-polarizing molecules of polyvinylalcohol/polyvinylene block copolymer material varying in length, n, of conjugated repeating vinylene unit of the polyvinylene block, wherein an absorption concentration of each of the polyvinylene blocks in the range of n&equals;19 to 25 is not less than approximately 65% of the absorption concentration of any of the polyvinylene blocks in the range of n&equals;14 or 15, wherein the absorption concentration is determined by absorption of wavelengths from about 200 nm to about 700 nm by the polyvinylene blocks, and wherein the molecularly oriented sheet exhibits a photopic dichroic ratio, R , of at least approximately 75.

Enhanced K-type polarizer

A liquid crystal display structure includes a liquid crystal display cell having a front surface and a back surface. One or more intrinsic polarizers lacking protective coatings thereon, such as K-type polarizers and thin KE polarizer sheets, are disposed adjacent to the front and back surfaces of the liquid crystal display cell. Alternatively, thinly cladded or encased iodine polarizers are disposed adjacent to the front and back surfaces of the liquid crystal display cell. The liquid crystal display structure may be used in conjunction with other optical display elements to enhance the brightness and contrast of the liquid crystal display.

Polarizers for use with liquid crystal displays

A visible range synthetic light polarizing element is provided, the optical and polarizing properties thereof having been selectively effected by regulated exposure of said polarizing element to ultraviolet irradiation. The ultraviolet irradiation can be either polarized or non-polarized, but in either case, is at intensities greater than that produced incidentally or by ambient ultraviolet irradiation sources. The resultant light-polarizing element is characterized by its heightened luminous transmittance, an improvement accomplished without departure from good polarization efficiency (i.e., greater than 99.9%).

Synthetic UV-bleached polarizer and method for the manufacture thereof

This invention relates to a new and improved light-polarizing sheet comprising molecularly oriented polyvinyl alcohol containing an oriented block segments of polyvinylene and said polyvinyl alcohol. In particular, the polarizing sheet comprises a polyvinylalcohol/polyvinylene block copolymer material wherein the polyvinylene blocks thereof are formed by molecular dehydration of a sheet of polyvinylalcohol; said sheet of polyvinylalcohol/polyvinylene block copolymer material comprising a uniform distribution of light-polarizing molecules of polyvinylalcohol/polyvinylene block copolymer material varying in the length, n, of the conjugated repeating vinylene unit of the polyvinylene block of the copolymer throughout the range of from 2 to 24; the concentration of each of said polyvinylene blocks, as determined by the absorption of wavelengths ranging from 200 to 700 nm remaining relatively constant, the degree of orientation of said light-polarizing molecules, as measured by the spectral dichroic ratio, R.sub.D, of said blocks, increasing throughout said range with increasing length, n, of said polyvinylene blocks; said polyvinylene block concentration and said degree of orientation of said molecules imparting to said sheet a photopic dichroic ratio, R.sub.D, of at least approximately 45.

High-efficiency K-sheet polarizer

Novel photopolymerizable compositions are provided which comprise a dye sensitizer, a linear polyethylenimine as a polymerization initiator and a free radical polymerizable ethylenic unsaturated monomer. In the preferred embodiments, the linear polyethylenimine is used in combination with lithium acrylate.

Photopolymerizable composition

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Upton, MA, United States of America

John J Cael