Patent ID: 8159417

Claim:
An image display device comprising: a display part which is configured to allow a user to visually recognize a display image by projecting an image light corresponding to the display image onto an eye of the user in a state where at least some ambient light reaches at least either one of eyes of the user; a measuring instrument which is configured to measure a brightness of the ambient light; a determination unit which is configured to determine a brightness of the display image; a detection unit which is configured to detect a difference between the brightness of the ambient light and the brightness of the display image; a decision unit which is configured to decide a stop timing where a use of the display part by the user is temporarily stopped based on a detection result of the detection unit after the use of the display part is started by the user; and a notification processing unit which is configured to perform a stopping-of-use notification which visually prompts the user to stop the use of the display part at the stop timing decided by the decision unit, wherein the decision unit is configured to accumulate, for every unit time, an allocated value allocated corresponding to the detection result of the detection unit, and is configured to decide a timing where the accumulated allocated value becomes a predetermined threshold value or more as the stop timing.