Electrochromic device

Claim 2

An electrochromic device which comprises an electrochromic layer comprising a transition metal compound sandwiched in between a first auxiliary electrochromic layer and a second auxiliary electrochromic layer, and each of the auxiliary electrochromic layers comprising at least one metal compound containing at least one metal different from the metal in the transition metal compound in the electrochromic layer, and the difference in electro-negativity between both metals being not more than 0.4 the thus sandwiched electrochromic layers being further sandwiched between opposed counter electrodes, at least one of said counter electrodes being light transmissive and each of said counter electrodes directly contacting the auxiliary electrochromic layer being a metallic electrode and electric current necessary for color forming of the electrochromic layer being capable of flowing through both auxiliary electrochromic layers.

Claim 3

An electrochromic device according to claim 1 in which the metal compounds contained in the first and the second auxiliary layer are similar or dissimilar and selected from the group consisting of ZnO, ZrO 2 , Ta 2 O 5 , Nb 2 O 5 , V 2 O 5 , TiO 2 , BaTiO 3 , CaTiO 3 , SrTiO 3 , ZrO 2 containing Y 2 O 3 , AgI, Ag 2 S, AgSI, Ag 3 SBr, Ag 6 I 4 WO 4 , beta Al 2 O 3 , ZnS, In 2 O 3 , SnO 2 and mixtures thereof.

Claim 4

An electrochromic device according to claim 1 in which the electrochromic layer contains a member selected from the group consisting of WO 3 , MoO 3 , TiO 2 , Nb 2 O 5 , Ta 2 O 5 and V 2 O 5 .

Claim 5

An electrochromic device according to claim 1 in which one of the first and the second auxiliary electrochromic layers is composed of a vapor-deposited film containing the metal compound and the other is composed of a coating film of a mixture composed of the metal compound dispersed in a binder.

Claim 6

An electrochromic device according to claim 1 in which the electrochromic layer is 500 A-10 μm in thickness.

Claim 7

An electrochromic device according to claim 1 in which the electrochromic layer is 2000 A-1 μm in thickness.

Claim 8

An electrochromic device according to claim 1 in which the first auxiliary electrochromic layer and the secondary auxiliary electrochromic layer are 100 A-20 μm in thickness.

Claim 9

An electrochromic device according to claim 1 in which one of the first and the second auxiliary electrochromic layers is a vapor-deposited film of 1000 A-1 μm thick.

Claim 10

An electrochromic device according to claim 1 in which the electrochromic layer, the first and the second auxiliary electrochromic layers, and the both electrodes are light transmissive.

Claim 11

An electrochromic device according to claim 1 in which at least one of the electrodes is a metal thin film having a reflection reducing coating.

Claim 12

An electrochromic device according to claim 1 in which a photo-semiconductive layer is added.

Claim 13

An electrochromic device according to claim 11 in which the photo-semiconductive layer contains a member selected from the group of ZnO and CdS.

Claim 14

An electrochromic device according to claim 11 in which the photo-semiconductive layer is a coating composed of a binder and a member selected from the group consisting of ZnO and CdS.

Claim 15

An electrochromic device according to claim 10 in which the reflection reducing coating is a metal compound thin film having a refractive index of 1.3-3.0 and is 100-1200 A in thickness.

Claim 16

An electrochromic device which comprises an electrochromic layer of 400 Angstroms to 10 microns in thickness comprising a transitional metal compound, said electrochromic layer sandwiched between a first auxiliary electrochromic layer and a second auxiliary electrochromic layer, each of the auxiliary electrochromic layers comprising at least one metal compound selected from the group consisting of ZnO, ZrO 2 , Ta 2 O 5 , Nb 2 O 5 , V 2 O 5 , TiO 2 , BaTiO 3 , CaTiO 3 , SrTiO 3 , ZrO 2 containing Y 2 O 3 , AgI, Ag 2 S, AgSI, Ag 3 SBr, Ag 6 I 4 WO 4 , beta-Al 2 O 3 , ZnS, In 2 O 3 , SnO 2 and mixtures thereof, such that the metal of at least one metal compound in each such auxiliary electrochromic layer is different from the metal in the transition metal compound in the electrochromic layer, and the difference in the electronegativity between both metals being not more than 0.4, the thus sandwiched electrochromic layers being further sandwiched between opposed counter electrodes, at least one of said counter electrodes being light transmissive and each of said counter electrodes directly contacting the auxiliary electrochromic layer being a metallic electrode and electric current necessary for color forming of the electrochromic layer being capable of flowing through both auxiliary electrochromic layers.

Claim 17

An electrochromic device which comprises an electrochromic layer of 400 Angstroms to 10 microns in thickness comprising a transitional metal compound, said electrochromic layer sandwiched between a first auxiliary electrochromic layer and a second auxiliary electrochromic layer, each of the auxiliary electrochromic layers comprising at least one metal compound selected from the group consisting of ZnO, ZrO 2 , Ta 2 O 5 , Nb 2 O 5 , V 2 O 5 , TiO 2 , BaTiO 3 , CaTiO 3 , SrTiO 3 , ZrO 2 containing Y 2 O 3 , AgI, Ag 2 S, AgSI, Ag 3 SBr, Ag 6 I 4 WO 4 , beta-Al 2 O 3 , ZnS, In 2 O 3 , SnO 2 and mixtures thereof, such that the metal of at least one metal compound in each such auxiliary electrochromic layer is different from the metal in the transition metal compound in the electrochromic layer, and the difference in the electronegativity between both metals being not more than 0.4, the thus sandwiched electrochromic layers being further sandwiched between opposed counter electrodes, at least one of said counter electrodes being light transmissive and each of said counter electrodes directly contacting the auxiliary electrochromic layer being a metallic electrode and electric current necessary for color forming of the electrochromic layer being capable of flowing through both auxiliary electrochromic layers.

Claim 18

An electrochromic device according to claim 15 in which at least one of the electrodes is a metal thin film having a reflection reducing coating.

Claim 19

An electrochromic device according to claim 15 in which a photo-semiconductive layer is added.

Claim 20

An electrochromic device according to claim 11 comprising a metal electrode, a first auxiliary electrochromic layer, an electrochromic layer, a second auxiliary electrochromic layer, a photo-conductive layer and a metal or metal oxide second electrode wherein at least one of said electrodes is light-transmissive.

Claim 21

An electrochromic device according to claim 17 comprising a metal electrode, a first auxiliary electrochromic layer, an electrochromic layer, a second auxiliary electrochromic layer, a photo-semiconductive layer and a metal or metal oxide second electrode wherein at least one of said electrodes is light-transmissive.