Electrochromic variable optical transmission device with a liquid electrolyte

• US 4,088,392 A
• Filed: 04/13/1976
• Issued: 05/09/1978
• Est. Priority Date: 04/13/1975
• Status: Expired due to Term

• Current Assignee: American Colloid Company (Minerals Technologies Incorporated)
• Original Assignee: American Colloid Company (Minerals Technologies Incorporated)
• Inventors: Meyers, Marion D.
• Primary Examiner(s): Sikes, William L.
• Application Number:
  US05/676,601
• Time in Patent Office: 756 Days
• Field of Search: 350/160 R
• US Class Current: 359/275
• CPC Class Codes: G02F 1/1524 Transition metal compounds

Abstract

Electro-optical device useful in control of visible and infrared absorption by windows in homes, commercial buildings and the like, typically comprising in sandwiched arrangement a pair of electrodes, and a film of a transition metal compound and a liquid electrolyte disposed between the electrodes is provided. The device exhibits coloration and bleaching thereof over large areas by control of, the polarity of an applied electric field.

Claims

1. A variable light transmission device which comprises in combination a layer of a solid persistent electrochromic material in contact with a separate layer of liquid electrolyte, said layer of liquid electrolyte and said layer of solid electrochromic material being disposed between and each contacting one of a pair of conductive electrodes.

2. The device of claim 1 wherein the electrochromic material contains at least one element of variable oxidation state.

3. The device of claim 1 wherein the liquid electrolyte is a strong sulfuric acid solution.

4. The device of claim 1 wherein the liquid electrolyte is in coextensive contact with the electrochromic material.

5. The device of claim 1 wherein at least one of the electrodes is substantially transparent.

6. A device as in claim 5 wherein the counter electrode is positioned so that light may pass through at least part of said transparent electrode.

7. The device of claim 1 wherein said persistent electrochromic material is tungsten oxide.