Developing apparatus with the following roller closer to the drum than the first roller

摘要

A developing apparatus is used for developing a photoconductive drum in a copying machine. The developing apparatus comprises a following developing roller for developing said photoconductive drum, an opposing developing roller for developing a photoconductive drum before the following developing roller, a supply mechanism for supplying developer to the developing rollers, a developer-quantity-regulator plate disposed between the following developing roller and the supply mechanism, and a limiting plate for limiting the length of the magnetic brush formed on the following developing roller. The distance between the photoconductive drum and the opposing developing roller is larger than the distance between the photoconductive drum and the following developing roller. The regulator plate is disposed apart from the developing rollers at a distance longer than the length of their magnetic brushes. The distance between the following developing roller and the limiting plate is within the length of the magnetic brush formed when the following developing roller starts rotating and the length of the magnetic brush formed when the following developing roller rotates at a constant speed.