ELECTROCHROMIC ELEMENT, OPTICAL FILTER, LENS UNIT, AND IMAGE PICK-UP APPARATUS

• US 20170235202A1
• Filed: 02/14/2017
• Published: 08/17/2017
• Est. Priority Date: 02/17/2016
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kubo, Wataru
• Granted Patent: US 10,303,033 B2
• Time in Patent Office: Days
• CPC Class Codes: G02F 1/1503 caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions
• CPC Class Codes: G02F 1/155 Electrodes

Abstract

The present invention provides an electrochromic element that includes a first electrode, a second electrode, and a third electrode, wherein at least one of the first electrode and the second electrode is a transparent electrode, and an electrolyte, an anodic organic electrochromic compound, and a cathodic redox substance are present between the first electrode and the second electrode, the third electrode is electrically connectable to the first electrode or the second electrode via the electrolyte, the third electrode contains an irreversibly oxidizable substance, and the oxidizable substance is not oxidized by a first oxidant of the anodic organic electrochromic compound but is more easily oxidizable than a reductant in an irreversible oxidation reaction of the anodic organic electrochromic compound.

Claims

1. An electrochromic element comprising:

a first electrode;

a second electrode; and

a third electrode, wherein;

at least one of the first electrode and the second electrode is a transparent electrode, and an electrolyte, an anodic organic electrochromic compound, and a cathodic redox substance are present between the first electrode and the second electrode,

the third electrode is electrically connectable to the first electrode or the second electrode via the electrolyte,

the third electrode contains an irreversibly oxidizable substance, and

the oxidizable substance is not oxidized by a first oxidant of the anodic organic electrochromic compound but is more easily oxidizable than a reductant in an irreversible oxidation reaction of the anodic organic electrochromic compound.

3. The electrochromic element according to claim 1, wherein:

the cathodic redox substance is a cathodic organic electrochromic compound,

the third electrode further contains an irreversibly reducible substance, and

the reducible substance is not reduced by a first reductant of the cathodic organic electrochromic compound but is more easily reducible than an oxidant in an irreversible reduction reaction of the cathodic organic electrochromic compound.

4. The electrochromic element according to claim 1, wherein an oxidation potential C of the oxidizable substance is between an oxidation potential A of a reversible first oxidation reaction of the anodic organic electrochromic compound and an oxidation potential B of an irreversible oxidation reaction of the anodic organic electrochromic compound.

6. The electrochromic element according to claim 4, wherein:

the cathodic redox substance is a cathodic organic electrochromic compound,

the third electrode further contains an irreversibly reducible substance, and

a reduction potential F of the reducible substance is between a reduction potential D of a reversible first reduction reaction of the cathodic organic electrochromic compound and a reduction potential E of an irreversible reduction reaction of the anodic organic electrochromic compound.

7. The electrochromic element according to claim 1, wherein the third electrode is disposed outside an optical path of light transmitted through the first electrode or the second electrode.

8. The electrochromic element according to claim 1, wherein at least one of the organic electrochromic compounds is immobilized on the first electrode or the second electrode.

9. The electrochromic element according to claim 1, wherein the third electrode is disposed on at least a portion around the first electrode or the second electrode.

10. The electrochromic element according to claim 1, further comprising at least one additional electrode having a composition that is the same as the third electrode.

11. The electrochromic element according to claim 6, further comprising at least one additional electrode having a composition that is the same as the third electrode.

12. The electrochromic element according to claim 1, further comprising a unit configured to control a potential difference between the first electrode or the second electrode and the third electrode.

13. The electrochromic element according to claim 1, further comprising a unit configured to detect a charge balance state of the electrochromic element.

14. The electrochromic element according to claim 6, further comprising a unit configured to detect a charge balance state of the electrochromic element.

15. The electrochromic element according to claim 13, wherein the unit configured to detect a charge balance state is a unit configured to detect a charge balance state by utilizing optical absorption of the organic electrochromic material.

16. An optical filter comprising:

the electrochromic element according to claim 1; and

an active element to be coupled to the electrochromic element.

17. A lens unit comprising:

an imaging optical system including a plurality of lenses; and

the optical filter according to claim 16.

18. An image pick-up apparatus comprising:

an imaging optical system including a plurality of lenses;

the optical filter according to claim 16; and

an image pick-up element configured to receive light transmitted through the optical filter.

19. The image pick-up apparatus according to claim 18, wherein the imaging optical system can be mounted in and removed from the image pick-up apparatus.

20. A window component comprising:

a pair of transparent substrates;

the electrochromic element according to claim 1 disposed between the pair of transparent substrates; and

an active element to be coupled to the electrochromic element.

2. An electrochromic element comprising:

a first electrode;

a second electrode; and

a third electrode, wherein;

at least one of the first electrode and the second electrode is a transparent electrode, and an electrolyte, a cathodic organic electrochromic compound, and an anodic redox substance are present between the first electrode and the second electrode,

the third electrode is electrically connectable to the first electrode or the second electrode via the electrolyte,

the third electrode contains an irreversibly reducible substance, and

the reducible substance is not reduced by a first reductant of the cathodic organic electrochromic compound but is more easily reducible than an oxidant in an irreversible reduction reaction of the cathodic organic electrochromic compound.

5. An electrochromic element according to claim 2, wherein a reduction potential F of the reducible substance is between a reduction potential D of a reversible first reduction reaction of the cathodic organic electrochromic compound and a reduction potential E of an irreversible reduction reaction of the anodic organic electrochromic compound.