Developing device having spaced rotatable members and a developer guide portion

A developing device comprising:

• a first chamber configured to accommodate a developer containing toner and a carrier;
• a first feeding screw provided in the first chamber and configured to feed the developer in the first chamber;
• a second chamber partitioned from the first chamber by a partition wall;
• a second feeding screw provided in the second chamber and configured to feed the developer in the second chamber, the second feeding screw having a rotation center positioned above a rotation center of the first feeding screw in a vertical direction;
• a first rotatable member to which the developer is supplied from the first chamber and configured to carry and feed the developer for developing an electrostatic latent image formed on an image bearing member;
• a first magnet fixedly provided inside the first rotatable member;
• a regulating member which is provided opposed to the first rotatable member and regulates an amount of the developer carried on the first rotatable member;
• a second rotatable member which is provided opposed to the first rotatable member, to which the developer is delivered from the first rotatable member by a magnetic field generated by the first magnet, and which is configured to carry and feed the developer for developing the electrostatic latent image, the second rotatable member having a rotation center positioned above a rotation center of the first rotatable member in the vertical direction;
• a second magnet fixedly provided inside the second rotatable member;
• a third rotatable member which is provided opposed to the second rotatable member, to which the developer is delivered from the second rotatable member by a magnetic field generated by the second magnet, and which is configured to carry and feed the developer for collecting, into the second chamber, the developer after the electrostatic latent image is developed with the developer, the third rotatable member having a rotation center positioned above the rotation center of the second rotatable member in the vertical direction;
• a third magnet fixedly provided inside the third rotatable member;
• and
• a guiding portion provided opposed to each of the second rotatable member and the third rotatable member and configured to guide the developer, to the second feeding screw, peeled off from the third rotatable member by a repelling magnetic field generated by the third magnet,
• wherein in a case that a shortest distance between the second rotatable member and the guiding portion is B [μm], and a shortest distance between the third rotatable member and the guiding portion is C [μm], the following relationship is satisfied:
• B
• +
• 100
• ⁢
• μ
• ⁢
• m
• ≤
• C
• .