An optical projection apparatus includs an illumination system, a projection lens and a reflective light valve between the illumination system and the projection lens. The device includes an SD card slot for an SD card to be inserted therein, and a converting adapter section configured to work as a converting adapter for the SD card. The method also includes initiating a snap-shot mode of the events recorder after a triggering event occurs in the sequence of events. Accordingly, any specific mechanism for only the cleaning purpose is not necessary and the construction of the apparatus can be made simple.