Foolproof device used in a process cartridge for an image forming apparatus

摘要

A foolproof device used in a process cartridge for an image forming apparatus, where the process cartridge has a developing device and a toner container, includes female engagement portions of two different sizes formed in the toner container, projections formed in the toner container, and male engagement portions of two different sizes formed in the developing device and adapted for guiding correct installation of the toner container in the developing device and securing the toner container to the developing device.