The 1st inlet in order to introduce the projector

摘要

PPROBLEM TO BE SOLVED: To provide an overheat protection device designed so that the use environment of an apparatus is grasped and the degree of clogging of an air filter is correctly determined, thereby controlling the numbers of revolutions of cooling fans according to the use environment, shutting off a power source, or sending sign for urging a user to clean or replace the air filter. PSOLUTION: The overheat protection device includes: a first suction port 2 and a second suction port 3 which introduce outdoor air into the apparatus; a first cooling fan 5 and a second cooling fan 6 disposed near the corresponding suction ports; and the air filter 4 disposed in the first suction port 2. The degree of clogging of the air filter 4 and the pressure of the outdoor air are detected by measuring the numbers of revolutions of the two fans and the temperature of the outdoor air, so as to perform efficient overheat protection of changing the numbers of the revolutions of the cooling fans according to the degree of clogging and the pressure of the outdoor air, sending a warning so that cleaning or replacement is carried out, and shutting off the power source, and the like. PCOPYRIGHT: (C)2009,JPO&INPIT