| 摘要 |
PROBLEM TO BE SOLVED: To safely and easily detect the installing state of a process cartridge without feeding a high voltage by operating a polygon motor and a laser beam generator when absence of toner is judged, and prohibiting the operation of a main motor and electrifying equipment when a light receiving sensor does not generate a BD signal in this operating state. SOLUTION: When toner can not be detected by a tarter detecting sensor 88, and no BD signal is generated when the laser beam emitted by a semiconductor laser beam generator 21 is mainly scanned by a polygon mirror 22, the optical path of laser beam is interrupted by a shutter member 51. Namely, it can be detected that a process cartridge is not installed, and no high voltage is fed to contacts 92, 93 for feeding electricity to the electrifying equipment of the process cartridge or a developing roller, which are provided in exposed state an the upper surface of a support plate 17. Thus, an operator never receives an electric shock even when he erroneously touches the contacts 92, 93. |
