Multiplex addressing of electrochromic displays

• US 4,129,861 A
• Filed: 01/27/1976
• Issued: 12/12/1978
• Est. Priority Date: 01/27/1976
• Status: Expired due to Term

• Current Assignee: American Colloid Company (Minerals Technologies Incorporated)
• Original Assignee: American Colloid Company (Minerals Technologies Incorporated)
• Inventors: Giglia, Robert D.
• Primary Examiner(s): Trafton, David L.
• Application Number:
  US05/652,935
• Time in Patent Office: 1,050 Days
• Field of Search: 340/324 R, 340/324 M, 340/166 EL, 340/176, 340/336, 315/202, 350/160 R, 350/357, 350/160 LC
• US Class Current: 345/49
• CPC Class Codes: G09G 3/19 using electrochromic devices

Abstract

An electrochromic data display and imaging device which may be formed by sandwich arrangement of the imaging area and the counter-electrode area with a suitable ion-conducting layer between.

The imaging area is in the form of discrete electrochromic areas in a desired pattern, and a circuit is provided for multiplexing these areas to provide alphanumeric or other type displays.

Claims

1. A display system comprising a plurality of persistent electrochromic display elements and means to multiplex said display elements, said means comprising diode means to provide a sufficient threshold voltage only to each display element to be displayed or erased and voltage threshold conduction means connected to each display element so that only a directly addressed element will be activated.

2. The device of claim 1 wherein said persistent electrochromic display elements comprise layered arrangements of a persistent electrochromic material and an ion-conducting medium in contact with a first electrode and a counter-electrode.

3. The device of claim 2 wherein said persistent electrochromic material is tungsten oxide.

4. The device of claim 2 wherein said ion-conducting medium is a mixture of sulfuric acid and glycerin.

5. The device of claim 2 wherein said counter-electrode comprises tungsten oxide.

6. A display means defined by claim 1 further comprising capacitor means in the supply circuit to each element in parallel with the opposed electrodes of the element.