DEVELOPER CONTAINING UNIT, DEVELOPMENT PROCESSING UNIT, DEVELOPMENT UNIT, AND IMAGE FORMING APPARATUS

摘要

A development unit (100) includes an attachable unit (300) and an attached unit (200). The attachable unit (300) includes an engaging section (301). The attached unit (200) includes an engaged section (201, 220) that allows the engaging section (301) to be brought into engagement with the engaged section (201, 220) attachably and detachably, and whose state changes in response to the engagement of the engaging section (301). The state of the engaged section (201, 220) upon the engagement of the engaging section (301) is maintained even after the engaging section (301) is detached from the engaged section (201, 220).