Electrochromic device with transmissive counter electrode

• US 4,278,329 A
• Filed: 06/05/1979
• Issued: 07/14/1981
• Est. Priority Date: 06/20/1978
• Status: Expired due to Term

• Current Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Masuda, Yasushi, Matsuhiro, Kenzi
• Primary Examiner(s): Davie, James W.
• Application Number:
  US06/045,664
• Time in Patent Office: 770 Days
• Field of Search: 350/357, 29/570
• US Class Current: 359/275
• CPC Class Codes: G02F 1/1524 Transition metal compounds
• CPC Class Codes: G02F 1/155 Electrodes

Abstract

An improved counter electrode used in an electrochromic device is transmissive in both charge injection and extraction states and exhibits excellent reversibility whereby it is optimum as a counter electrode in a transmissive electrochromic device which is useful as a display device in its control of visible and infrared absorption by a window and the like.

Claims

1. In an electrochromic device comprising two transparent substrates, each having formed thereon a transparent conductive film which face each other;

first and second electrochromic films which are formed on the transparent conductive films;

an electrolyte containing ions capable of changing the optical properties of the electrochromic film and a sealant for sealing the electrolyte between the two substrates, wherein the improvement comprises;

said first electrochromic film being formed of a substance whose optical properties in the range of visible light change in response to the injection and extraction of said ions; and

said second electrochromic film being formed of a substance whose optical properties in the range of visible light do not change in response to the injection and extraction of said ions.

2. An electrochromic device according to claim 1 wherein said second electrochromic film is a crystalline tungsten oxide film having porous structure formed by depositing by a vacuum evaporation in a vacuum degree of from 5×

10^-4 to 2×

10^-3 torr on the transparent conductive film and baking at from 350°

to 450°

C.

3. An electrochromic device according to claim 1 wherein said first electrochromic film is an amorphous film containing tungsten oxide and said second electrochromic is a crystalline film containing tungsten oxide.

4. An electrochromic device having a laminated structure comprising:

a transparent substrate;

a first electrochromic film made of a substance having the property that a reversible injection and extraction of anions and electrons does not change its optical properties in the range of visible light;

an insulating film in which anions may be injected, but electrons may not be substantially injected;

a second electrochromic film made of a substance having the property that a reversible injection and extraction of anions and electrons does change its optical properties in the range of visible light; and

a transparent conductive film.

5. An electrochromic device according to claim 4 wherein said first electrochromic film is a crystalline film containing tungsten oxide which has a porous structure being capable of injection and extraction of ions.

6. An electrochromic device according to claim 4 wherein said second electrochromic film is an amorphous film containing tungsten oxide which has a porous structure being capable of injection and extraction of ions.