The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 23, 1985
Filed:
Oct. 22, 1982
Horst Ballmer, Heidenheim, DE;
Carl-Zeiss-Stiftung, Heidenheim/Brenz, Oberkochen, DE;
Abstract
In order to control the absorptance of an electrochromic layer, the invention provides a plurality of steps for establishing different levels of coloring action. Quantities of charge are supplied to and removed from the layer, via one or the other of two constant-current sources, timed with clock pulses to a forward/backward counter. For decoloring processes, smaller quantities of charge are removed from the layer than are supplied to it during a corresponding coloring process. The quantities of charge removed for decoloring processes are, however, slightly greater than the quantities of removed charge needed to reach steps having exactly the same absorptance, so that even in the case of numerous changes between the color steps, destruction of the layer is definitely avoided. Preferred fields of use are lenses, particularly eyeglass lenses, filters and dimmable mirrors, each having an applied electrochromic layer whose absorptance is controlled for step-wise change.