Patent ID: 7527680

Claim:
A projection type video display for applying an optical modulation to light emitted from a light source by a light valve, and projecting image light obtained by this optical modulation, comprising: an air-cooling means for cooling the inside of the display by air; a filter provided at an outside-air intake port; a duct connected to the outside-air intake port; an air-current amount sensor for detecting the volume of air drawn from the outside-air intake port, the air-current amount sensor being provided in the duct; a barometric pressure sensor for detecting atmosphere pressure, the barometric pressure sensor being provided outside the duct; a memory for storing a table in which warning instructions determined by an air-current amount value and an atmosphere pressure value and control contents concerning a cooling power of the air-cooling means determined by the air-current amount value and the atmosphere pressure value are defined; and a controller for reading information from the table based on an air-current amount value detected by the air-current amount sensor and an atmosphere pressure value by the barometric pressure sensor and generating a warning signal when the information read from the table is a warning instruction.