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.

Date of Patent:
Oct. 25, 1983

Filed:

Mar. 11, 1982
Applicant:
Inventor:

Hubert Portmann, Colombier, CH;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G09G / ;
U.S. Cl.
CPC ...
340785 ; 340805 ; 340812 ; 350357 ;
Abstract

An electrochromic display cell has several electrode segments 1 spaced from a common counter-electrode 3 by an electrolyte 2 and disposed to represent different symbols according to those segments on which a coloured or effaced state is conferred by application of a current in one direction or in the other between the segments and the counter-electrode. To achieve one of the current directions a bias voltage provided by a generator 16 is applied for a fixed time by a switching circuit T1, T2 to a field-effect transistor T6 which completes a circuit through the cell 4, electrode 3, electrolyte 2 and segment 1. The transistors 6 have channel widths proportional to the segment areas so that all segments receive the same charge per unit area. The segments whose state is to change in the other direction are short-circuited with the counter-electrode by transistors T7. The display is particularly useful for the display of time data on watches.


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