ELECTROCHROMIC COLOR DISPLAY HAVING DIFFERENT ELECTROCHROMIC MATERIALS

摘要

An electrochromic display comprises electrochrome pixels (10) which comprise at least a first electrochrome material (EL1) and a second electrochrome material (EL2) between two electrodes (E1, E2). Each of the electrochrome materials (EL1, EL2) has two stable states, in one state at a first voltage across the electrochrome pixel (10) the material is transparent, in the other state at a second voltage across the electrochrome pixel (10) the material absorbs a color and thus is colored. The material changes from the one state to the other state by applying the appropriate one of the first or the second voltage. The amount of change of the absorption of the color depends on the time the appropriate voltage is applied. The first electrochrome material (EL1) changes from a transparent state to a color absorbing state for at least partly absorbing a first color when a pixel voltage (VP) across the electrochrome pixel has the first value (V1). The first electrochrome material (EL1) changes from the color absorbing state to the transparent state when the pixel voltage (VP) has a second value (V2) which has a polarity opposite to the first value (V1). The second electrochrome material (EL2) changes from a transparent state to a color absorbing state for at least partly absorbing a second color different than the first color when the pixel voltage (VP) has a third value (V3) which has an absolute value smaller than an absolute value of the first value (V1). The second electro-chrome material (EL2) changes from the color absorbing state to the transparent state when the pixel voltage (VP) has a fourth value (V4) which has a polarity opposite to the third value (V3). An absolute value of the fourth value (V4) is smaller than an absolute value of the second value (V2).