Patent ID: 8688015

Claim:
A development device, comprising: a developer carrier configured to carry on a surface thereof a developer, the developer carrier being disposed to face a latent image carrier; a developer tank having the developer carrier; a developer container configured to house the developer to be supplied to the developer tank, the developer container being connected to the developer tank through a partition having an opening; and a developer carrier member configured to carry the developer in the developer container, the developer being supplied to the developer tank from the opening while being carried by the developer carrier member, the amount of developer to be supplied to the developer tank from the opening being gradually increased in a developer carrying direction of the developer carrier member, and the opening including an apex that is a leading part of the opening when moving along a length of the opening in the developer carrying direction, such that a first peripheral section of the opening that extends from the apex is positively sloped relative to the developer carrying direction, and a second peripheral section of the opening that extends from the apex is negatively sloped relative to the developer carrying direction.