Patent ID: 8021003

Claim:
A projection display apparatus, comprising: a light source; a power supply unit which receives power from an external power supply and which supplies power derived from the received power to the light source; a detecting unit which detects a cut-off state in which no or no sufficient power is being received by the power supply unit from the external power supply; a nonvolatile memory for storing data of the projection display apparatus; a capacitor which accumulates charges when power is being received by the power supply unit from the external power supply, and forms part of the power supply unit; and a control unit operable, following detection by the detecting unit of the cut-off state, to carry out a data storage operation in which at least part of the data is stored in the nonvolatile memory, wherein power necessary for carrying out the data storage operation is obtained from charges previously accumulated by the capacitor, wherein the control unit is operable, following detection by the detecting unit of the cut-off state, to prevent charges previously accumulated by the capacitor from being consumed by the light source.