A projector includes: an image information input unit to which an SD card storing image information and a group ID is coupled; a screen displaying an image based on the image information; a communication unit coupled via a network to another projector having an SD card storing image information, the communication unit communicating with the another projector; and a control unit determining whether a group ID corresponding to the group ID is stored in the SD card or not, based on communication by the communication unit, the control unit synchronizing a display of the image by the screen and a display of an image based on the image information by the another projector when the group ID is stored in the SD card.

A projector includes: an image information input unit to which an SD card storing image information and a group ID is coupled; a screen displaying an image based on the image information; a communication unit coupled via a network to another projector having an SD card storing image information, the communication unit communicating with the another projector; and a control unit determining whether a group ID corresponding to the group ID is stored in the SD card or not, based on communication by the communication unit, the control unit synchronizing a display of the image by the screen and a display of an image based on the image information by the another projector when the group ID is stored in the SD card.