3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

3m Intellectual Properties Company

David L Wortman

Sanford Cobb, Jr

Andrew John Ouderkirk

Michael F Weber

James M Jonza

Brian D Cull

Olester Benson, Jr

Carl A Stover

Mark E Gardiner

Kenneth A Epstein

Mark B O'Neill

Wade D Kretman

David J Wirtanen

Steven M Hamer

Harry B Anderson

Thomas J Lunn

Sanford Cobb

Franklyn L 3M Center Frederickson

Chad J 3M Center Carter

Kanta 3M Center Kumar

Michael A 3M Center Semonick

Optical devices according to the present invention include a multilayer optical film in which at least one of the layers comprises an oriented birefringent polymer. The multilayer optical film exhibits low absorptivity and can reflect light approaching at shallow angles as well as normal to the film.

High efficiency optical devices

A multiple layer reflective polarizeris described. This element is placed between and optical cavityand an LCD moduleto form an optical display. The reflective polarizer reflects some light into the optical cavitywhere it is randomized and may ultimately emerge with the correct polarization to be transmitted out of the display.

Display having a reflective polarizer

Optical devices such as backlight assemblies, according to the present invention include a multilayer optical film in which at least one of the layers comprises an oriented birefringent polymer. The multilayer optical film exhibits low absorptivity and can reflect light approaching at shallow angles as well as normal to the film.

Brightness enhancing reflective polarizer

The present invention includes a backlight system incorporating a back reflector and/or a lamp cavity reflector constructed of a multilayer optical film.

Backlight system with multilayer optical film reflector

A transflector is described which increases efficiency and brightness under both ambient and supplemental lighting conditions in visual display applications. In one embodiment, the transflector includes a reflective polarizing element that reflects one polarization of light and transmits the other. In an alternate embodiment, the transflector includes a reflective polarizing element and a diffusing element such that the transflector diffusely reflects light of one polarization and transmits the other. The transflector is useful for both reflective and transflective liquid crystal displays.

Transflective displays with reflective polarizing transflector

Optical devices such as light pipes which incorporate multilayer optical films in which the refractive indices of two adjacent layers in the thickness direction are substantially matched or are small relative to the difference in refractive indices of said two adjacent layers in an given in-plane direction which is at least 0.05. The multilayer optical film exhibits low absorptivity and can reflect light approaching at shallow angles as well as normal to the film.

A multiple layer reflective polarizer is described. This element is placed between and optical cavity and an LCD module to form an optical display. The reflective polarizer reflects some light into the optical cavity where it is randomized and may ultimately emerge with the correct polarization to be transmitted out of the display.

Reflective polarizer having improved properties and optical display with improved reflective polarizer

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 polaizer when reflecting light. Still other optical devices use diffusely reflecting polarizers to recycle light and improve display illumination.

Optical devices using reflecting polarizing materials

A lightguide includes an input edge surface, a back surface and an output surface. A reflector is directly secured to the back surface by, for example, adhesive bonding.

Lightguide having a directly secured reflector and method of making the same

A polarized light source includes a diffuse light source and a reflective polarizing element placed proximate thereto. The reflective polarizing element transmits light of a desired polarization and reflects light of another polarization back into the diffuse source where it is randomized. Some of the initially rejected light is thus converted into the desired polarization and is transmitted through the reflective polarizing element. This process continues, and the repeated reflections and subsequent randomization of light of the undesired polarization increases the amount of light of the desired polarization that is emitted by the polarized light source.

Growing community of inventors

Saint Paul, MN, United States of America

David L Wortman