Patent ID: 8355655

Claim:
A development apparatus comprising: a developer bearing member which bears and conveys developer; a thickness restriction member which restricts developer quantity at the developer bearing member; a first chamber which can accommodate developer which is to be to supplied to the developer bearing member, wherein the first chamber comprises an opening portion to which a part of the developer bearing member is exposed; a second chamber which forms a circulation passage along with the first chamber and which retrieves developer used for development at the developer bearing member; a conveying member which conveys developer in the circulation passage formed by the first chamber and the second chamber; and a controller which is capable of controlling rotation speed of the conveying member and rotation speed of the developer bearing member so that a ratio Vsc/Vsl in a first mode is less than a ratio Vsc/Vsl in a second mode, wherein Vsc denotes the rotation speed of the conveying member and Vsl denotes the rotation speed of the developer bearing member.