Patent ID: 7972012

Claim:
A method for controlling a projector, wherein the projector includes: a housing; a target object housed inside the housing; a cooling device for performing cooling of the target object; a first temperature sensor disposed in an anterior stage of the target object on a cooling path formed by the cooling device inside the housing; a second temperature sensor disposed in a posterior stage of the target object on the cooling path; and a control device for calculating an estimated temperature of the target object from the first detection temperature and the second detection temperature, and controlling the cooling device based on the result of the calculation, the method comprising: measuring a first detection temperature in an anterior area of the cooling path among peripheral areas of the target object using the first temperature sensor; measuring a second detection temperature in a posterior area of the cooling path among the peripheral areas using the second temperature sensor; performing the calculation of the estimated temperature of the target object using a predetermined conversion formula that includes a term having the first detection temperature that is added to a term having a square root of a temperature difference obtained by subtracting the first detection temperature from the second detection temperature, the conversion formula being represented by the following formula: T p =T r +a √{square root over (T i −T r )} +b where Tp denotes the estimated temperature of the target object, Tr denotes the first detection temperature, Ti denotes the second detection temperature, and a and b are constants determined in accordance with a heat release value of the target object, an internal structure of the projector, or an arrangement of the temperature sensors; and controlling the cooling device based on the result of the calculation.