Provided is an electrochromic display element including a first substrate, a first electrode over the first substrate, a first electrochromic layer over the first electrode, an electrolyte layer over the first electrochromic layer, a second electrode over the electrolyte layer, and a second substrate over the second electrode. The first electrochromic layer contains tin oxide having an average primary particle diameter of less than 30 nm and an electrochromic compound containing a functional group bindable to the tin oxide. The amount by mole of the electrochromic compound per area of the first electrochromic layer is from 2.0×10.sup.−8 mol/cm.sup.2 through 2.0×10.sup.−7 mol/cm.sup.2.

Provided is an electrochromic display element including a first substrate, a first electrode over the first substrate, a first electrochromic layer over the first electrode, an electrolyte layer over the first electrochromic layer, a second electrode over the electrolyte layer, and a second substrate over the second electrode. The first electrochromic layer contains tin oxide having an average primary particle diameter of less than 30 nm and an electrochromic compound containing a functional group bindable to the tin oxide. The amount by mole of the electrochromic compound per area of the first electrochromic layer is from 2.0×10.sup.−8 mol/cm.sup.2 through 2.0×10.sup.−7 mol/cm.sup.2.

An electrochromic device and an electrochromic method therefor are disclosed. The electrochromic device comprises a first substrate, a first transparent conductive layer, a first electrochromic layer, an electrolyte layer, a second electrochromic layer, a second transparent conductive layer, and a second substrate which are sequentially stacked. Both the first electrochromic layer and the second electrochromic layer are made of a cathode electrochromic material or made of an anodic electrochromic material. The electrochromic method for the electrochromic device comprises: circularly applying a voltage having a direction opposite to and same as that of a first voltage to a pretreated electrochromic device. Because a structure in which two layers of electrochromic layers are made of the anodic electrochromic material or the cathode electrochromic material is used, and a specific electrochromic method is combined, the switching between different colors can be performed, and a selection range of the electrochromic materials can be expanded.

This disclosure includes variable light transmission panels (VLTPs) and their assembly into insulated glass units (IGUs), which can be incorporated into buildings. Disclosed windows provide uniform appearance from outside during the day when a number of such windows are incorporated in a building regardless of their state of light transmission. These disclosures may also be used to make windows which tint to different transmitted colors but during the day still appear to be uniform from outside.

The present disclosure relates to an electrochromic material having a relatively high response speed and a reversible discoloration even by a relatively low driving voltage and an electrochromic particle, a transmittance variable panel and a transmittance variable display device including the electrochromic material.

An electrochromic composition, an electrochromic layer and an electrochromic device are provided. The electrochromic composition includes 20-80 parts by weight of polyimide, 20-80 parts by weight of silicon oxide nanoparticle, 1-50 parts by weight of electrochromic material, and 850 to 1200 parts by weight of solvent. The polyimide is a reaction product of a dianhydride and a diamine. The dianhydride and the diamine are as defined in the specification.

An electrochromic composition, an electrochromic layer and an electrochromic device are provided. The electrochromic composition includes 20-80 parts by weight of polyimide, 20-80 parts by weight of silicon oxide nanoparticle, 1-50 parts by weight of electrochromic material, and 850 to 1200 parts by weight of solvent. The polyimide is a reaction product of a dianhydride and a diamine. The dianhydride and the diamine are as defined in the specification.

The present invention relates to metal-based tris-bipyridyl complexes, e.g., iron-based tris-bipyridyl complexes, and their use in fabrication of surface confined assemblies for electrochromic applications. Formulae I and II. ##STR00001##

A method for preparing an electrochromic device. In the method the device is prepared by inserting monovalent cations into a reducing electrochromic layer in advance, for instance, through a dry process. In particular, the method involves inserting monovalent cations into an electrochromic layer which includes a reducing electrochromic material. Then, subsequently and sequentially, placing an electrolyte layer and an ion storage layer on the electrochromic layer. In this way, it is possible to improve driving durability of the electrochromic device.

A vehicle display device using a hetero electrochromic film according to the present invention includes a projection part configured to project a predetermined image on one or more of a windshield and a window, a hetero electrochromic film formed on one or more of the windshield and the window, and a driving part configured to drive the projection part and the hetero electrochromic film.