Patent ID: 7967447

Claim:
An overheat prevention device for use in a projection apparatus, the projection apparatus comprising a light source module and a power circuitry, the overheat prevention device comprising: an inclination detector adapted to detect an inclination angle, greater than 0 and less than 90 degrees, of the light source module relative to a reference plane, and transmit an inclination signal according to the inclination angle; a cooling module, comprising a first fan and a second fan; and a control circuitry, which connects with the inclination detector and the cooling module, for controlling one of the cooling module and the power circuitry to alter an operation mode of the projection apparatus in response to the inclination signal; wherein the control circuitry controls the cooling module by controlling the first fan from a first rotational speed down to a second rotational speed and controlling the second fan from the first rotational speed up to a third rotational speed in response to the inclination signal.