Patent ID: 8676094

Claim:
A developing device comprising: a developer container that houses a developer; a developer holding body that is supported by the developer container and includes a magnet member including a plurality of magnetic poles on an outer peripheral surface of the magnet member, and a substantially cylindrical member that is provided outside the magnet member and rotates while holding the developer on an outer surface of the substantially cylindrical member, the developer being attracted by a magnetic force of the magnet member; a transport member that transports the developer while stirring the developer and includes a rotating shaft extending along the developer holding body, and a substantially spiral transport blade supported by the rotating shaft; a layer-thickness regulating member that faces the developer holding body and regulates a thickness of a layer of the developer held on the developer holding body; the magnet member including an attracting magnetic pole that causes the developer transported by the transport member to be attracted to the developer holding body; and an interrupting member that is arranged between the developer holding body and the transport member and interrupts movement of the developer, the interrupting member intersecting with a first virtual plane and a second virtual plane, the first virtual plane being adjacent to a rotation locus of an outer edge in a radial direction of the transport blade, the first virtual plane passing through a facing position at which the layer-thickness regulating member faces the developer holding body, the first virtual plane being adjacent to the rotation locus at a position at which a speed in a circumferential direction of the transport blade has a speed component in a direction toward the layer-thickness regulating member, the second virtual plane passing through a rotation center of the developer holding body and a rotation center of the transport member, the interrupting member interrupting the movement of the developer that is pushed in the radial direction of the transport blade when the developer is transported by the transport member and that moves toward the developer holding body, wherein the interrupting member and the transport member overlap in a gravity direction, and the interrupting member is disposed above the transport member in the gravity direction.