3m Innovative Properties Company

Robert M Moshrefzadeh

Patrick A Thomas

Jeffrey C Chang

Hsin-hsin Chou

Colleen M Brenner-Watschke

Hassan Sahouani

Daniel R Croswell

A rear projection screen assembly is described that includes a diffuser and a polarizer. The diffuser has particles dispersed within a binder. The particles and the binder have different refractive indices and are chosen such that the diffuser spreads light of an initial polarization state a cone of angles while substantially preserving the initial polarization state of the light. The diffuser also substantially depolarizing a portion of the light that is laterally scattered in the diffuser. The polarizer is disposed to receive light transmitted through the diffuser. The polarizer transmits light of the initial polarization state while absorbing a portion of the laterally scattered light that has a different polarization state. The resolution of the overall screen assembly may be made higher while also improving other characteristics of the screen assembly.

Rear projection screen

Projection screen assemblies include one or more birefringent retarding layers and one or more polarizing layers. The retarding and polarizing layers reduce the unwanted reflection of ambient and image light. One embodiment of a screen assembly includes a dispersing layer having an input side to receive light from a light source and a first retarding layer disposed to alter the polarization of the light transmitted by the dispersing film. A first polarizer substantially transmits light received from the first retarding layer in a first polarization state and absorbs light received from the first retarding layer in a second polarization state orthogonal to the first polarization state.

Rear projection screen with enhanced contrast

Growing community of inventors

Oakdale, MN, United States of America

Robert M Moshrefzadeh