Optical control circuit for electrochromic layers

US4529873A · kind A · utility

Assignee

• Carl-Zeiss-Stiftung, Heidenheim/Brenz · DE

Inventors

• Horst Ballmer · Heidenheim, DE
• Erwin Wiedmann · Oberkochen, DE

Key dates

• Filing date: Oct 15, 1982
• Grant date: Jul 16, 1985
• Expiry date: Oct 15, 2002

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B60R1/088
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

In order to regulate the absorptance of an electrochromic layer, the absorptance of the layer is measured optically. The signal derived therefrom is compared with a guide value and fed to a controller which has a dead zone between two hysteresis regions (at switch points), and charges are fed to or removed from the layer as required. Preferred fields of use are lenses, particularly eyeglass lenses, filters and dimmable mirrors to which an electrochromic layer is applied with provision for controlled change of its absorptance.