Screen for a free and a restricted viewing mode

US10712488B2 · kind B2 · utility

Assignee

• siOPTICA GmbH · DE

Inventors

• André Heber · Weimar, DE
• Uwe Schroeter · Naschhausen, DE
• Juergen Schwarz · Apolda, DE
• Ambrose Peter Nari · Jena, DE
• Markus Klippstein · Jena, DE
• Stepan Alkhimenko · Jena, DE

Key dates

• Filing date: Jun 28, 2018
• Grant date: Jul 14, 2020
• Expiry date: Jun 28, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F1/133626
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

An illuminating apparatus for a screen operable in at least two operating modes, viz B1 for a free viewing mode and B2 for a restricted viewing mode. The illuminating apparatus comprising: a backlight with a planar extension radiating light in a restricted angular range; a plate-shaped light guide that is, in a viewing direction, arranged in front of the backlight and with outcoupling elements one of the large surfaces and/or within its volume. The light guide is transparent to at least 70% of the light emitted by the backlight and light sources are arranged laterally at the edges of the light guide. Various parameters are specified for the number of outcoupling elements per unit area and for their extension, and in operating mode B2, the backlight is switched on and the light sources are switched off. In operating mode B1 at least the light sources are switched on.