# US 2018/0024407 A1 · Electrochromic element, method of driving the same, optical filter, lens unit, image pick-up apparatus, and window > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0024407 A1 - Document ID: US20180024407A1 - Status: Published application - Kind: A1 - Application number: 15/708,418 - Filed: 2017-09-19 - Published: 2018-01-25 - Earliest claimed: 2015-06-03 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Wataru Kubo; Kazuya Miyazaki - Web page: https://patentgrep.com/patent/US20180024407A1 ## CPC - G02F 1/155: Electrodes - G02F 1/1503: caused by oxidation-reduction reactions in organic liquid solutions, e.g. viologen solutions - G02F 1/163: Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract Provided is an electrochromic element, including: a first electrode and a second electrode, at least one of the first electrode and the second electrode being transparent; a third electrode; and an electrolyte, an anodic organic electrochromic material, and a cathodic organic electrochromic material that are arranged between the first electrode and the second electrode, in which the third electrode is electrically connectable to at least one of the first electrode and the second electrode via the electrolyte, and in which the third electrode has an effective area that is larger than an effective area of the first electrode and an effective area of the second electrode. ## Claims ### Claim 1 An electrochromic element comprising: a first electrode; a second electrode; an auxiliary electrode; an electrochromic material disposed between the first electrode and the second electrode; and a switch, wherein the switch switches between applying a voltage between the first electrode and the second electrode and applying a voltage between the first electrode and the auxiliary electrode. ### Claim 2 (depends on 1) The electrochromic element according to claim 1, wherein an effective area of the auxiliary electrode is larger than an effective area of the first electrode and an effective area of the second electrode. ### Claim 3 (depends on 1) The electrochromic element according to claim 1, at least one of the first electrode and the second electrode is transparent. ### Claim 4 (depends on 1) The electrochromic element according to claim 1, wherein the auxiliary electrode is arranged out of an optical path of light that passes through at least one of the first electrode and the second electrode. ### Claim 5 (depends on 1) The electrochromic element according to claim 1, wherein the auxiliary electrode is arranged in at least a part of a periphery of one of the first electrode and the second electrode. ### Claim 6 (depends on 1) The electrochromic element according to claim 1, wherein the auxiliary electrode comprises a porous electrode. ### Claim 7 (depends on 1) The electrochromic element according to claim 1, wherein the auxiliary electrode comprises a metal oxide. ### Claim 8 (depends on 1) The electrochromic element according to claim 1, further comprising an electrolyte disposed between the first electrode and the second electrode. ### Claim 9 (depends on 1) The electrochromic element according to claim 1, wherein the electrochromic material comprises an anodic organic electrochromic material and a cathodic organic electrochromic material, and wherein at least one of the anodic organic electrochromic material and the cathodic organic electrochromic material is fixed to one of the first electrode and the second electrode. ### Claim 10 (depends on 1) The electrochromic element according to claim 1, further comprising a structure arranged between the auxiliary electrode and one of the first electrode and the second electrode, wherein the structure is configured to reduce substance transport between the auxiliary electrode and the one of the first electrode and the second electrode. ### Claim 11 (depends on 1) The electrochromic element according to claim 1, further comprising a unit configured to detect a charge balance state of the electrochromic element. ### Claim 12 (depends on 11) The electrochromic element according to claim 11, wherein the unit configured to detect the charge balance state comprises a unit configured to detect the charge balance state using light absorption of the electrochromic material. ### Claim 13 (depends on 1) An optical filter, comprising the electrochromic element of claim 1. ### Claim 14 (depends on 13) An image pick-up apparatus, comprising: the optical filter of claim 13; and a light-receiving element configured to receive light that has passed through the optical filter. ### Claim 15 (depends on 13) A lens unit, comprising: the optical filter of claims 13; and an optical system including a plurality of lenses. ### Claim 16 (depends on 1) A window, comprising the electrochromic element of claim 1. ### Claim 17 A method of driving an electrochromic element, the electrochromic element comprising: a first electrode; a second electrode; an auxiliary electrode; a switch; and an electrochromic material disposed between the first electrode and the second electrode, the method comprising: controlling a voltage to be applied between the first electrode and the second electrode or between the first electrode and the auxiliary electrode. ### Claim 18 (depends on 17) The method according to claim 17, wherein the controlling of the voltage is performed depending on a detected charge balance state of the electrochromic element.