Developing device having magnetic flux density distribution

A developing device comprising:

• a rotatable developer carrying member for carrying a developer including non-magnetic toner and a magnetic carrier;
• a developer regulating member, having a magnetic property, for regulating an amount of the developer on said developer carrying member;
• a supporting portion for supporting opposite ends of said developer regulating member;
• and
• a cylindrical magnetic field generating member which is provided inside said developer carrying member and which has a plurality of magnetic poles including a regulating magnetic pole provided opposed to said developer regulating member,
• wherein a magnetic flux distribution provided by said regulating magnetic pole includes a first local maximum portion on a side upstream, with respect to a rotational direction of said developer carrying member, of a closest position between said magnetic field generating member and said developer regulating member, a second local maximum portion on a side downstream of the closest position with respect to the rotational direction, and a local minimum portion at a position between said first local maximum portion and said second local maximum portion,
• wherein as seen from a rotational axis direction of said developer carrying member, a rectilinear line connecting the closest position between said magnetic field generating member and said developer regulating member and a center of said magnetic field generating member is positioned between the first local maximum portion and the second local maximum portion with respect to the rotational direction, and
• wherein a cross-sectional shape of said developer regulating member as seen from a rotational axis direction of said developer carrying member is a circular shape.