DEVELOPING DEVICE FOR IMAGE FORMING DEVICE

PURPOSE:To effectively prevent fine-grain toner from being leaked out by providing a seal material provided with the magnetic layer of specified saturation magnetic flux density at a gap part between a developer carrier and the end edge of a developing device. CONSTITUTION:The seal material 7 provided with the magnetic layer 71 having the saturation magnetic flux density of 2000 gauss or more on the surface is disposed at the gap part between the developing sleeve (developer carrier) 5 of the developing device 2 arranged by being closely brought into contact with a photosensitive body 1 and the end edge of the developing device 2. A magnetic substance is dispersed in resin as the forming means of the magnetic layer 71. Besides, such a proper means that a magnetic vapor deposition film is formed can be utilized and any means which can obtain the satulation magnetic flux density of 2000 gauss or more can be used. Thus, the toner is stably prevented from flowing out from the developing device 2, specially from the gap part between a developing container on the downstream side of the sleeve 5 for a long term.