Patent ID: 9442428
Filing Date: 2016-09-13
CPC Classification: G03G

Claim Text:
1. A developing apparatus comprising: a developer carrying member configured to carry a developer; and a magnet member disposed inside said developer carrying member, said magnet member including one or more first magnet portions having a first magnetic polarity at an outer surface thereof opposing an inner surface of said developer carrying member, and one or more second magnet portions having a second magnetic polarity at an outer surface thereof opposing the inner surface of said developer carrying member, the second magnetic polarity being different from the first magnetic polarity, and the first magnet portions and the second magnet portions being provided at different positions with respect to a circumferential direction of said developer carrying member; wherein in a cross-section perpendicular to a longitudinal direction of said magnet member at a longitudinally central portion of said magnet member, a number of said first magnet portions is larger than a number of said second magnet portions, and wherein a ratio of a total area of said first magnet portions in the cross-section is smaller at a longitudinally end portion of said magnet member than at the longitudinally central portion.