Patent ID: 8818245

Claim:
A developing device having comprising: a housing that houses a two-component developer containing a carrier and a toner, wherein the developer is replenished in the housing while the developer is gradually ejected to outside from an outlet of the housing; a transport passage provided in the housing and in which the developer is transported; a transport member provided in the housing and configured to rotate to transport the developer; an ejection passage which diverges from the transport passage such that a part of the developer transported in the transport passage is conveyed in the ejection passage to the outlet; and a restriction unit configured to restrict an amount of developer ejected from the outlet so that a first amount of developer is ejected per rotation of the transport member from the outlet when the transport member rotates at a first speed, and a second amount of developer is ejected per rotation of the transport member from the outlet when the transport member rotates at a second speed that is higher than the first speed, wherein the second amount of developer ejected per rotation of the transport member when the transport member rotates at the second speed is smaller than the first amount of developer ejected per rotation of the transport member when the transport member rotates at the first speed, and wherein the restriction unit comprises: a shutter configured to move and close the outlet by covering the outlet; and a moving mechanism configured to move the shutter so that the outlet is opened for a first time period per rotation of the transport member when the transport member rotates at the first speed, and the outlet is opened for a second time period per rotation of the transport member when the transport member rotates at the second speed, the second time period being shorter than the first time period, wherein the moving mechanism moves the shutter so as to close the outlet so that developer is not ejected from the outlet during periods other than the first time period or the second time period.