A developing apparatus, includes: a developer bearing member that is rotatable; an moving member configured to move the magnetic developer carried on the developer bearing member before the magnetic developer is restricted by a restricting member, the moving member being rotatable and brought into contact with a surface of the developer bearing member; and a control portion, wherein, at a contact position between the developer bearing member and the moving member, assuming that a moving speed vector of a surface of the developer bearing member is taken as R and a moving speed vector of a surface of the moving member is taken as r, the control portion controls rotational operation of the developer bearing member and the moving member such that a direction of a vector Rr during image formation and a direction of a vector Rr during non-image formation be opposite to each other.

A developing device includes a developing container, a first stirring conveyance member, a second stirring conveyance member, a developer carrying member including a developing sleeve and a magnet, and a regulation member. The regulation pole in the magnet has a region extending over 10 or more in which a maximum value of a vertical magnetic force is not more than 65 [mT] and a vertical magnetic force gradient is not more than 0.3 [mT/]. A peak position of the vertical magnetic force gradient of the regulation pole is arranged at a position opposed to the second stirring conveyance member, and when a value of the vertical magnetic force gradient and a value of the vertical magnetic force at the peak position of the vertical magnetic force gradient are indicated as A [mT/] and K [mT], respectively, A2.8 and AK62.5 are satisfied.

A developing apparatus, includes: a developer bearing member that is rotatable; an moving member configured to move the magnetic developer carried on the developer bearing member before the magnetic developer is restricted by a restricting member, the moving member being rotatable and brought into contact with a surface of the developer bearing member; and a control portion, wherein, at a contact position between the developer bearing member and the moving member, assuming that a moving speed vector of a surface of the developer bearing member is taken as R and a moving speed vector of a surface of the moving member is taken as r, the control portion controls rotational operation of the developer bearing member and the moving member such that a direction of a vector Rr during image formation and a direction of a vector Rr during non-image formation be opposite to each other.

A developing device includes a developing container storing a two-component developer containing a magnetic carrier and a toner, a developer carrying member carrying the developer on its outer circumferential surface, and a regulation member arranged to be opposed at a prescribed distance to the developer carrying member. The developer carrying member includes a developing sleeve on which a magnetic brush is formed, and a magnet secured in the developing sleeve and having a plurality of magnetic poles including a regulation pole opposed to the regulation member and a downstream-side magnetic pole arranged downstream of the regulation pole with respect to the rotation direction of the developing sleeve. The magnet is such that the vertical magnetic force gradient [mT/] has a local minimum value near a position at which the vertical magnetic force is 0 [mT] between the downstream-side surface of the regulation member and the downstream-side magnetic pole.

Warpage of a developer regulating member formed of a magnetic material and unrotatably supported on only both end portions thereof caused when receiving pressure of developer or magnetic force is suppressed. In a cross section of the developer regulating member orthogonal to a rotational axis of the developer beading member, an area of the cross section of the developer regulating member is smaller than 28 mm.sup.2, a magnitude of a normal direction component of a second moment of area of the developer regulating member with respect to a centroid of the cross section is larger than 25 mm.sup.4, and a magnitude of a tangent direction component of the second moment of area is larger than 70 mm.sup.4. The normal direction component and the tangent direction component are respectively components in the normal direction and the tangent direction of the developer bearing member.

A developing apparatus includes a developing container to accommodate a developer and having first and second chambers divided by a partition wall for supplying the developer to a rotatable developing member and first and second communicating portions to allow the developer to move between first and second chambers by conveyance screws. A third communicating portion is disposed between the first and second communicating portions and above the conveyance screws to allow air inside the developing container to move between the first chamber and the second chamber. The developing container further includes a third chamber disposed above the second chamber in the vertical direction and accommodates initial developer in an unused state of the developing apparatus, and an opening portion for discharging the air inside the developing container to outside of the developing container is provided in the third chamber, with the opening being disposed above the third chamber.

A developing device includes a rotatable developing sleeve for carrying a developer including toner and a magnetic carrier and for developing an electrostatic latent image, formed on an image bearing member, in a developing region where the developer contacts the image bearing member; and a magnetic field generating portion provided inside the developing sleeve and having a developing pole provided at a position opposing the image bearing member in order to form the developing region, wherein a ratio of an 80%-value-width of magnetic flux density of the developing pole with respect to a normal direction of the developing sleeve to a half peak width of the magnetic flux density of the developing magnetic pole with respect to the normal direction is 0.65 or more, and with respect to a rotational direction of the developing sleeve, a magnetic force of the developing pole in the normal direction of the developing sleeve in each of neighborhoods of both end portions of the developing region is larger than a magnetic force of the developing pole at a central portion of the developing region.

An image forming apparatus includes a plurality of image carriers, a charging device, an exposure device, a development device, and an intermediate transfer belt. The image carrier has a surface on which an amorphous silicon photosensitive layer is formed. The intermediate transfer belt is a plastic belt having a surface resistivity of 9.5 to 10.5 (log ?/square). An offset amount of the primary transfer roller from the image carrier is 0 to 2 (mm), a contact surface pressure between the image carrier and the intermediate transfer belt is 0.5 to 1.5 (gf/mm.sup.2), and a charge density of primary transfer current that flows when the primary transfer voltage is applied to the primary transfer roller is 0.016 to 0.040 (?C/cm.sup.2).

Only both end portions of a developer regulating member are supported by a developing container such that the developer regulating member cannot rotate, a size of an area of a cross section orthogonal to a rotational axis of a developer bearing member of the developer regulating member is smaller than 28 mm.sup.2, a magnitude of second moment of area in a normal direction of the developer bearing member with respect. to a centroid of the cross section orthogonal to the rotational axis of the developer bearing member of the developer regulating member is larger than 25 mm.sup.4, and a magnitude of a second moment of area in a tangent direction of the developer bearing member with respect to the centroid of the cross section orthogonal to the rotational axis of the developer bearing member of the developer regulating member is larger than 70 mm.sup.4.

An image forming method forms a color toner image and a white toner image using an image forming apparatus having a plurality of developing machines. The color toner image is formed using a color developer containing a first carrier and at least one color toner selected from a yellow toner, a magenta toner, and a cyan toner. The white toner image is formed using a white developer containing a second carrier and a white toner containing at least titanium oxide as a pigment. Formula (1):
Iw<Ic(1)
is satisfied. Ic (A) is a dynamic current value of the first carrier at 100 V and Iw (A) is a dynamic current value of the second carrier at 100 V.