Day and night film

US7419272B2 · kind B2 · utility

Assignee

• 3M INNOVATIVE PROPERTIES COMPANY · US

Inventors

• Kay-Uwe Schenke · Neuss, DE
• Guido Hitschmarin · Neuss, DE
• Stefan Dietrich · Potsdam, DE
• Robert Bennett · Aylesbury, GB
• Paul E. Humpal · Stillwater, US
• Keith M. Kotchick · Windom, US

Key dates

• Filing date: Dec 8, 2005
• Grant date: Sep 2, 2008
• Expiry date: Dec 8, 2025

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F1/133555
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

An optical element having a front side and a back side operates in an ambient lit mode and a backlit mode. The optical element includes a diffusely reflecting layer facing the front side for reflecting ambient light. A light absorbing layer faces the back side and is positioned to prevent back light from illuminating the diffusely reflecting layer. A plurality of light transmitting regions extend through the light absorbing layer and the diffusely reflecting layer for permitting back light to pass through in a restricted angular range without illuminating the diffusely reflecting layer.