A syringe assembly for dispensing medicine from a cartridge having a diaphragm and a piston opposite the diaphragm. The pointer controlling apparatus permits a pointer to move into a predetermined region after a predetermined period of time has elapsed from a point in time when the pointer comes into contact with a boundary line of the predetermined region. Therefore, rigidity of the cassette is improved. It is then determined to activate the built-in flash unit based on the analysis.