Electrochromic device

• US 6,952,299 B1
• Filed: 03/31/2003
• Issued: 10/04/2005
• Est. Priority Date: 08/29/2002
• Status: Expired due to Fees

• Current Assignee: Murakami Corporation
• Original Assignee: Murakami Corporation
• Inventors: Fukazawa, Akihiko, Minami, Chihiro
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): CHOI, WILLIAM C
• Application Number:
  US10/401,894
• Time in Patent Office: 918 Days
• Field of Search: 359/265, 359/267, 359/269, 359270-273, 359/275, 252/500, 252/583, 252/586, 252/600
• US Class Current: 359/275
• CPC Class Codes: G02F 1/1524 Transition metal compounds
• CPC Class Codes: G02F 2001/1557 Side by side arrangements of working and counter electrodes
• CPC Class Codes: G02F 2203/01 transmissive
• CPC Class Codes: G02F 2203/02 reflective
• CPC Class Codes: G02F 2203/48 Variable attenuator

Abstract

The present invention provides an electrochromic device in which a color during the coloring mode is gray. A lower ITO transparent electrode film 12 constituting a lower electrode film is formed on a transparent glass substrate 10. On the lower ITO transparent film 12, a nickel oxides film 32 constituting an oxidation coloring layer, a tantalum oxide film 16 constituting a solid-state electrolyte layer, a mixture film 34 of tungsten oxide and titanium oxide constituting a reduction coloring layer and an lower ITO transparent electrode film 20 constituting a upper electrode film are formed sequentially. The color during the coloring mode is gray and the color during the bleaching mode is achromatic.

Claims

1. An electrochromic device comprising:

a reduction coloring layer made of a material containing tungsten oxide and titanium oxide;

an oxidation coloring layer made of a material containing nickel oxides;

an electrolyte layer sandwiched between the reduction coloring layer and the oxidation coloring layer; and

a number of tungsten atoms contained in the reduction coloring layer being greater than a number of titanium atoms contained in the reduction coloring layer such that a color of the electrochromic device is gray during a coloring mode.

2. The electrochromic device according to claim 1, wherein said reduction coloring layer is a film made of a mixture containing tungsten oxide and titanium oxide as main components or a film made of a mixture containing tungsten oxide as a main component and titanium oxide as an additive, and said oxidation coloring layer is a film containing nickel oxides as a main component.

3. The electrochromic device according to claim 1, wherein a ratio of the number of titanium atoms to a sum of the number of tungsten atoms and the number of titanium atoms is at least 5% and at most 40%.

4. The electrochromic device according to claim 3, wherein the ratio is at least 20% and at most 30%.

5. The electrochromic device according to claim 1, wherein said tungsten oxide contains WO₃ as a main component, said titanium oxide contains TiO₂ as a main component and said nickel oxides contains NiO as a main component.

6. The electrochromic device according to claim 1, wherein said nickel oxides contains Ni(OH)₂.

7. The electrochromic device according to claim 1, wherein said reduction coloring layer is amorphous and said oxidation coloring layer is crystalline, fine-crystalline or amorphous.

8. The electrochromic device according to claim 1, wherein said reduction coloring layer is configured to perform reactions expressed by at least one of following formulas 1 and 2 by applying voltage, and wherein said oxidation coloring layer is configured to perform reactions expressed by at least one of following formulas 3, 4 and 5:

9. The electrochromic device according to claim 1, wherein said reduction coloring layer contains a component of a film formed from a dual evaporation method which uses WO₃ and TiO₂ as a starting materials, and said oxidation coloring layer contains a component of a film formed from an evaporation method which uses NiO as a starting material.

10. The electrochromic device according to claim 1, wherein a peak value of voltage applied during the coloring mode is 1.75 V or more.

11. The electrochromic device according to claim 1, wherein a peak value of voltage applied during the coloring mode is 2 V or more.

12. The electrochromic device according to claim 1, wherein a color during a bleaching mode is an achromatic color.

13. An electrochromic device comprising:

a first plate member;

a first electrode layer provided on the first plate member;

an oxidation coloring layer provided on the first electrode layer and made of a material containing nickel oxides;

an electrolyte layer provided on the oxidation coloring layer;

a reduction coloring layer provided on the electrolyte layer and made of a material containing tungsten oxide and titanium oxide;

a second electrode layer provided on the reduction coloring layer;

a second plate member provided on the second electrode layer;

at least one of a first combination of the first electrode layer and the first plate member and a second combination of the second electrode layer and the second plate member being transparent; and

a number of tungsten atoms contained in the reduction coloring layer being greater than a number of titanium atoms contained in the reduction coloring layer such that a color of the electrochromic device is gray during a coloring mode.

14. The electrochromic device according to claim 13, wherein all of the first electrode layer, the first plate member, the second electrode layer and the second plate member are transparent.

15. The electrochromic device according to claim 14, wherein the electrochromic device is utilized as an exposure control element on an optical axis of an image pickup device in a digital camera.

16. The electrochromic device according to claim 13, wherein one of the first combination of the first electrode layer and the first plate member and the second combination of the second electrode layer and the second plate member is transparent, and wherein an electrode layer of another of the first combination and the second combination is made of a metal reflecting film.

17. The electrochromic device according to claim 16, wherein the electrochromic device is utilized to constitute a reflectivity-variable mirror.

18. The electrochromic device according to claim 13, wherein the electrolyte layer is a solid-state electrolyte layer.

19. The electrochromic device according to claim 13, further comprising:

a base member on which one of the first plate member and the second plate member is provided.

20. The electrochromic device according to claim 19, further comprising:

a sealing resin adhered to another of the first plate member and the second plate member.

21. The electrochromic device according to claim 20, wherein all of the base member, the sealing resin, the first electrode layer, the first plate member, the second electrode layer and the second plate member are transparent.

22. The electrochromic device according to claim 21, wherein the electrochromic device is utilized as an exposure control element on an optical axis of an image pickup device in a digital camera.

23. The electrochromic device according to claim 20, wherein the first plate member is provided on the base member, the sealing resin is adhered to the second plate member, one of a third combination of the base member, the first electrode layer and the first plate member and a fourth combination of the sealing resin, the second electrode layer and the second plate member is transparent, and an electrode layer of another of the third combination and the fourth combination is made of a metal reflecting film.

24. The electrochromic device according to claim 23, wherein the electrochromic device is utilized to constitute a reflectivity-variable mirror.

25. The electrochromic device according to claim 13, wherein said reduction coloring layer is a film made of a mixture containing tungsten oxide and titanium oxide as main components or a film made of a mixture containing tungsten oxide as a main component and titanium oxide as an additive, and said oxidation coloring layer is a film containing nickel oxides as a main component.