Patent ID: 7944596

Claim:
A display medium comprising: a pair of electrodes disposed with a gap therebetween; an electrolyte disposed between the pair of electrodes; an electroconductive porous layer disposed at least one of the pair of electrodes, at the side facing the other electrode; a first electrochromic dye held by the porous layer; a second electrochromic dye movably dispersed in the electrolyte and forming a color different from the color of the first electrochromic dye; wherein both the first electrochromic dye and the second electrochromic dye are oxidation dyes which form colors by an electrochemical oxidation reaction and are rendered color-faded by an electrochemical reduction reaction, or reduction dyes which form colors by an electrochemical reduction reaction and are rendered color-faded by an electrochemical reduction reaction, and the threshold values of respective voltages applied to the pair of the electrodes to change each of the first electrochromic dye and the second electrochromic dye from a color-faded state to a colored state satisfy the relationship represented by the following Formula (1): E1<E2 Formula (1) wherein in Formula (1), E 1 represents the absolute value of the threshold value of the voltage applied to the pair of the electrodes to change the first electrochromic dye from a color-faded state to a colored state, and E 2 represents the absolute value of the threshold value of the voltage applied to the pair of the electrodes to change the second electrochromic dye from a color-faded state to a colored state.