Patent application number | Description | Published |
20080199210 | Developing device - A developing device comprises: a housing that stores developer; a developing roll that is rotatably supported in the housing and has a developing region with a roughened surface that supplies developer to an image region of an image holding member; a step portion that is formed at both sides of the developing region of the developing roll and whose diameter is smaller than that of the developing region; and a seal member that contacts a region of the step portion that is opposite to the image holding member. | 08-21-2008 |
20110222878 | DEVELOPING DEVICE AND IMAGE FORMING DEVICE - A developing device includes: a plurality of developer retaining bodies that retain developer and rotate, and that respectively convey the developer, which is supplied to each of the developer retaining bodies from a developer supply section, to an image bearing body that rotates and bears a latent image; and a speed changing unit that is adapted to change a rotation speed of at least one of the developer retaining bodies excluding a developer retaining body that is furthest downstream side in a direction of rotation of the image bearing body. | 09-15-2011 |
20110229214 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device includes: a first developer holding body with a first cylinder member disposed facing the outer peripheral surface of a rotating latent image holding body, and a first magnet disposed at the inside of the first cylinder member; a second developer holding body with a second cylinder member disposed facing the outer peripheral surface of the latent image holding body, further downstream in the latent image holding body rotation direction than the first developer holding body, and a second magnet disposed at the inside of the second cylinder member; and an adjustment mechanism that adjusts the relative position of the first magnet to the second magnet in a circumferential direction. | 09-22-2011 |
20120039637 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device includes: a developing member including a magnetism-generating member having plural magnetic poles polarized in a circumferential-direction thereof, and a rotating member that is rotated about the magnetism-generating member; a developer-pumping pole provided in the magnetism-generating member, and that pumps up the developer, which is supplied from a developer accommodating portion, to the rotating member surface; a developer-peeling-off pole provided in the magnetism-generating member below a rotation axis of the rotating member in a vertical direction on an upstream side of the developer-pumping pole in a rotational-direction of the rotating member, that peels off the developer from the rotating member surface; and a magnetic body provided in at least a portion between a facing position facing the developer-peeling-off pole in a circumferential-direction of the rotating member and an intermediate position between the developer-peeling-off pole and the developer-pumping pole in the circumferential direction, facing the rotating member surface. | 02-16-2012 |
20120230737 | DEVELOPING DEVICE, VISIBLE IMAGE FORMING DEVICE, AND IMAGE FORMING APPARATUS - A developing device includes a developer container; a developer holding body including a magnet member and a substantially cylindrical member; a transport member including a rotating shaft and a substantially spiral transport blade; a layer-thickness regulating member; and an interrupting member that is arranged between the developer holding body and the transport member, that intersects with a first virtual plane passing through a facing position between the regulating member and the developer holding body and being adjacent to a rotation locus of a radial-direction outer edge of the transport blade at a position at which a speed in a circumferential direction of the transport blade has a speed component toward the regulating member, and a second virtual plane passing through rotation centers of the developer holding body and transport member, and that interrupts movement of the developer pushed and moving in the radial direction of the transport blade. | 09-13-2012 |
20120251189 | IMAGE FORMING APPARATUS - An image forming apparatus includes a rotating image carrier, a charging device, a latent image forming device, a developing device having a developer holder and developing a latent image as a visible image, a voltage application unit that generates a potential difference between the image carrier and the developer holder to form an electric field, by which toner is directed toward the latent image, in a developing region, and a transfer device that transfers the visible image of the image carrier to a medium, wherein the developer holder having a concavo-convex portion having a convex portion and a concave portion is provided in an outer surface thereof and formed such that the volume resistivity of a portion corresponding to the convex portion is set to be larger than the volume resistivity of a portion corresponding to the concave portion. | 10-04-2012 |
20130230341 | DEVELOPING DEVICE AND IMAGE-FORMING APPARATUS - A developing device includes a developer-carrying member and a developer control member, a supply member, and a rotating member that are disposed opposite the developer-carrying member. The developer-carrying member accommodates a magnetic source that generates a magnetic force for carrying a developer containing magnetic particles on an outer surface thereof. The developer control member controls the thickness of a layer of the developer carried on the outer surface of the developer-carrying member. The supply member rotates to transport the developer in a rotation axis direction thereof and to supply the developer to the developer-carrying member. The rotating member is disposed at a position where the rotating member is submerged in the developer between the developer control member and the supply member and rotates to supply the developer from between the developer control member and the supply member to the supply member. | 09-05-2013 |
20130236215 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device includes a housing accommodating a developer containing a toner and a magnetic carrier; first and second developing members facing an image bearing member and having substantially-cylindrical first and second rotatable sleeves and first and second magnet rollers supported therein and having magnetic poles; a supply member supplying the developer onto the first sleeve; a layer regulating member facing the first sleeve and regulating a layer of the developer; and an electrode member facing the second sleeve with a distance therebetween and disposed upstream, in the second-sleeve rotational direction, of where the second sleeve receives the developer from the first sleeve and downstream of where the second developing member faces the image bearing member. An electric field removing the toner from the second sleeve or causing the toner on the carrier to adhere onto the second sleeve is generated between the electrode member and the second sleeve. | 09-12-2013 |
20140193176 | DEVELOPER-AGITATING TRANSPORTER, DEVELOPING DEVICE, AND IMAGE FORMING APPARATUS - A developer-agitating transporter includes helical blades that helically extend around a rotation shaft, the helical blades being arranged at different positions in a direction perpendicular to a longitudinal direction of the rotation shaft; and a gap portion that divides each helical blade into a first blade portion and a second blade portion, which oppose each other across the gap portion, so that the helical blade is discontinuous in a direction in which the helical blade extends. The gap portion causes the first blade portion and the second blade portion to be arranged at a certain angular interval in a circumferential direction of the rotation shaft, and at least one surface of adjacent ones of the helical blades that are adjacent in the circumferential direction of the rotation shaft has a sloped area that is sloped at an angle that changes with respect to an axial direction of the rotation shaft. | 07-10-2014 |
20140235415 | TRANSPORTING MEMBER, DEVELOPING DEVICE, AND IMAGE FORMING APPARATUS - A transporting member includes multiple helical blades that helically extend around a rotation shaft and that have an upstream-side blade and a downstream-side blade, an end portion of the upstream-side blade and an end portion of the downstream-side blade overlapping in a direction perpendicular to an axial direction of the rotation shaft, the multiple helical blades transporting an object in the axial direction via rotation of the rotation shaft; a gap portion that divides the upstream-side blade and the downstream-side blade, the upstream-side blade and the downstream-side blade being arranged at a certain angular interval in a circumferential direction of the rotation shaft; and a regulating portion that regulates an amount of the object that passes through a space between the upstream-side blade and the downstream-side blade in a direction in which the object is transported. | 08-21-2014 |
20140286681 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device includes a sleeve and a magnet roller having first and second magnetic poles, the second magnetic pole being disposed downstream of the first magnetic pole. A magnetic attraction distribution on the sleeve in a region from the first magnetic pole to the second magnetic pole is such that the magnetic attraction decreases from a position of the first magnetic pole toward the downstream side, a gradient of change in the magnetic attraction decreases in a region downstream of a region in which a gradient of reduction in the magnetic attraction temporarily increases, thereby forming an attraction reduction region in which the magnetic attraction is reduced so that developer cannot be held on the sleeve, and the gradient of change in the magnetic attraction increases in a region downstream of the attraction reduction region so that the magnetic attraction increases to a position of the second magnetic pole. | 09-25-2014 |