Prolonged coloration electrochromic assembly

An electrochromic assembly comprising:

• first and second optically aligned electrochromic devices defined by a sheet of transparent material, first and second layers of electrochromic material adjacent opposing surfaces of said sheet, the transmittance of each of said layers being variable when an electrical field is applied thereacross, and electrical means for applying an electrical field across each of said layers of electrochromic material;
• and
• switch means for first applying electrical power to one of said first and second devices for a first short period of time to cause coloration of said one device while bleaching the other of said devices to a colorless, substantially transparent state and secondly applying electrical power to said other device for a second short period of time to cause coloration of said other device while bleaching said one device to a substantially colorless, transparent state, and thereafter alternately applying electrical power and bleaching said devices cyclically in the same manner;
• whereby coloration segregation in both of said first and second devices is reduced when said assembly is operated over prolonged periods of time.

An electrochromic assembly comprising:

• first, second and third optically transparent elements aligned generally in tandem with one another, each element having a peripheral edge and front and rear surfaces, said third and second elements being spaced respectively from said front and rear surfaces of said first element;
• at least one of a liquid, thickened liquid, gel and semi-solid electrochromic material confined in said spaces adjacent both surfaces of said first element, said electrochromic material having a light transmittance which varies when an electric field is applied thereacross;
• seal means extending around the periphery of said assembly spacing said elements apart and confining said electrochromic material within said spaces;
• electrical means for selectively applying electrical power for short periods of time across said electrochromic material in one of said spaces to reduce the light transmittance therethrough and for selectively bleaching at other times said electrochromic material in said one of said spaces, and for selectively applying electrical power for short periods of time across said electrochromic material in said other space and for selectively bleaching at other times said electrochromic material in said other space, said electrical means including means for causing the electrochromic material in said other space to bleach during application of electrical power to the electrochromic material in said one space, and vice versa during continued, cyclical operation of said assembly, whereby coloration segregation in said electrochromic material in both said spaces is reduced when said assembly is operated over prolonged periods of time and the depth of coloration of said assembly may be made greater than that from one of said spaces.

An electrochromic assembly comprising:

• first and second tandemly mounted electrochromic elements, each of said elements having a layer of electrochromic material, the transmittance of which varies when an electrical field is applied thereacross and a pair of electrically conductive busses adapted to applying an electrical field across said layer;
• a power source including first and second power terminals and means for applying electrical power thereacross, said power source being adapted to changing each of said elements from a substantially transparent condition to a colored condition;
• means for connecting one of said power terminals to one of said busses of each of said elements;
• first switch means for alternatingly connecting the other one of said busses of one of said elements to said first and second power terminals;
• second switch means for alternatingly connecting the other one of said busses of the other one of said elements to said first and second power terminals;
• and
• control means for causing said first and second switch means to switch between said first and second power terminals whereby one of said elements is colored when said other element is bleached and vice-versa on an alternating basis.