IMAGE DISPLAY DEVICE, IMAGE DISPLAY SYSTEM, AND METHOD OF CONTROLLING IMAGE DISPLAY DEVICE

An image display device includes: a clock section for timing current date/time information including a date and a time; an expiration date/time storage section for storing expiration date/time information as information of a date/time until which use of the image display device is allowed; a password accepting section for accepting input of a password encoded based on predetermined expiration date/time information; a decoding section for decoding the predetermined expiration date/time information from information of the password accepted by the password accepting section; a comparison section for comparing the predetermined expiration date/time information decoded by the decoding section and the current date/time information timed by the clock section with each other; and an expiration date/time update section for storing the predetermined expiration date/time information in the expiration date/time storage section if the predetermined expiration date/time information decoded is a date/time one of on and later than the current date/time information.