Patent ID: 7859513

Claim:
An image display device, comprising: an image display medium wherein charged particle groups are sealed between a pair of substrates at least one of which has translucency and which are opposed to each other with a space therebetween, and display density is changed by transfer of the charged particle groups between the pair of substrates according to an electric field formed by a voltage applied between the substrates; a temperature measuring unit that measures a temperature of the image display medium; and a voltage applying unit that applies, between the substrates, a driving voltage according to the temperature of the image display medium that is measured by the temperature measuring unit, based on a predetermined voltage applying condition corresponding to the temperature of the image display medium in order to display an image in predetermined display density on the image display medium, wherein a voltage applying unit applies the driving voltage according to temperature ranges including: a first temperature range in which the temperature of the image display medium is less than a first temperature, wherein the charge amount of the charged particle groups is within a first range, a second temperature range in which the temperature of the image display medium is equal to or greater than the first temperature, but less than a second temperature, the second temperature being higher than the first temperature by a predetermined temperature, wherein the charge amount is less than the charge amount at any temperature of the first range, and a third temperature range in which the temperature of the image display medium is equal to or greater than the second temperature, which is the temperature at which the charged particle groups do not transfer between the pair of substrates even if the driving voltage is applied, wherein the charge amount is within a second range which is less than the first range by a predetermined amount, and the voltage applying unit prohibits application of the driving voltage to the image display medium.