| 摘要 |
PROBLEM TO BE SOLVED: To provide a system for preventing unauthorized use of a projection type projector, which eliminates the need of password input not to hamper user-friendliness and is capable of preventing unauthorized use.SOLUTION: The system for preventing unauthorized use of a projection type projector includes an unauthorized use preventing device and a security part provided in a projection type projector. The unauthorized use preventing device includes a first positioning unit which measures its location on the earth to output first location information, and a first transmission unit which transmits the first location information to the outside by radio. The security part includes: a second positioning unit which measures its location on the earth to output second location information; a first reception unit which receives the first location information; a location comparison unit which determines whether an inter-device distance calculated on the basis of the first and second location information is shorter than a threshold distance or not to output a location comparison result signal; and an AND calculation unit which operates AND between the location comparison result signal and a power-on signal showing whether the power source of the projection type projector is turned on or not and outputs the operation result. |
