Patent ID: 7989747

Claim:
A projector, comprising: a heat dissipation device for dissipating heat produced by the projector; a power supply circuit for powering the heat dissipation device; a rechargeable cell for receiving and storing electrical power from the power supply circuit; a first switching circuit connected between the heat dissipation device and the rechargeable cell for controlling the rechargeable cell to power the heat dissipation device when the power supply circuit stops powering the heat dissipation device; a detector for detecting an on-and-off state of the projector, outputting a recharge signal when the projector is powered on, and outputting a discharge signal when the projector is powered off; and a second switching circuit for establishing a connection between the power supply circuit and the rechargeable cell when receiving the recharge signal, and cutting off the connection when receiving the discharge signal, or when the power supply circuit stops supplying the electrical power; wherein the first switching circuit is further configured for controlling the rechargeable cell to power the heat dissipation device when the connection is cut off.