3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

3m Innovative Properties

Ronald J Tabar

Richard C Allen

William Ward Merrill

Peter D Condo

Elisa M Cross

Susan L Kent

Timothy J Nevitt

Stephen A Johnson

Timothy J Hebrink

Joseph A Gangi

Robert Charles Fitzer

Andrew John Ouderkirk

Kenneth L Smith

Sanford Cobb, Jr

Jaime R Ojeda

David I Wortman

David B Redmond

Optical devices using reflective polarizers and, in particular, diffusely reflective polarizers are provided. Many of the optical devices utilize the diffusely reflecting and specularly transmitting properties of diffusely reflecting polarizers to enhance their optical characteristics. The optical devices include a lighting system which uses a reflector formed from a diffusely reflecting polarizer attached to a specular reflector. Another optical device is a display apparatus which uses a diffusely reflecting polarizer layer in combination with a turning lens which folds shallow angle light toward a light modulating layer. Other optical devices exploit the depolarizing characteristics of a diffusely reflecting polarizer when reflecting light. Still other optical devices use diffusely reflecting polarizers to recycle light and improve display illumination.

Optical devices using reflecting polarizing materials

An improved optical film having a continuous/disperse phase morphology and a method for making the same is provided. At least one of the continuous and disperse phases comprises a blend of homopolymers which are inter-reacted, as by transesterification. The resulting films exhibit a higher degree of birefringence for a given level of strain than analogous films in which the blend is replaced by a random copolymer.

Method for making optical devices from homopolymers

Optical device having continuous and disperse phases

Optical device containing polymeric material domains having different degrees of randomness

Optical films and processes for forming the optical films are described in which materials having different properties are used and the different properties are exploited to obtain improved optical and/or mechanical properties of the optical film. The different properties of the materials may be used to select processing conditions under which the materials will react differently. The film may be processed with respect to two different directions with the amount of molecular orientation, if any, induced by the process being separately controlled for each material and each direction.

Optical film and process for manufacture thereof

A novel microprismatic retroreflective film or sheeting is provided which comprises a transparent semicrystalline polymer. The microprismatic retroreflective film or sheeting of the present invention offers superior retroreflective brightness at large angles of incidence and at large observational angles. Syndiotactic vinyl aromatic polymers, especially syndiotactic polystyrene and copolymers thereof, are preferred semicrystalline polymers, as they impart good dimensional stability and resistance to moisture, and can be made resistant to UV radiation. Signing materials comprising these microprismatic retroreflective films provide improved performance for off-angle illumination and viewing in traffic control and other signing applications.

Angular brightness microprismatic retroreflective film or sheeting incorporating a syndiotactic vinyl aromatic polymer

Flexible optically uniform sign face substrate comprising at least one layer of durable thermoplastic sheeting and an optically uniform dimensionally stable scrim film, and more particularly a sign face substrate comprising at least one layer of optically uniform dimensionally stable multilayer scrim film laminated between at least two layers of durable thermoplastic sheeting for use in areas such as awning, canopy, fascia or sign material construction.

Flexible optically uniform sign face substrate

Growing community of inventors

Saint Paul, MN, United States of America

Ronald J Tabar