Electrochromic indicator device with reflecting background

US4787717A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Jutta Heinz geb Belgardt · Gerlingen, DE
• Helmut Sautter · Ditzingen, DE
• Rainer Schink · Leonberg, DE
• Lothar Weber · Stuttgart, DE

Key dates

• Filing date: Mar 22, 1983
• Grant date: Nov 29, 1988
• Expiry date: Mar 22, 2003

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F1/1533
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A pigment is mixed with an epoxy resin or varnish binder in a weight ratio from 5:1 to 6:1 to make a paste, which is then applied as a thin layer by screen printing on top of the counterelectrode layer previously baked onto a metal substrate. In another baking step the new layer for producing a reflective coating is heated to between 120.degree. and 180.degree. C., in which temperature range the binder produces small bubbles before hardening, so that the layer that is produced is permeable to ions when the layer becomes soaked with electrolyte in the assembled electrochromic device. The metal substrate is shaped by drawing to provide the electrolyte cavity after the application of the counterelectrode and the reflecting background layer thereon, since the deformation does not damage either of these layers.