Patent application number | Description | Published |
20090066982 | IMAGE FORMING APPARATUS - The image forming apparatus includes image forming parts, a developing device and a cleaner to clean at least the intermediate transfer material or the transfer device, wherein at the image forming operation starting time, in each image forming part, after starting the charging, the application of the developing bias is started before the top end of the charging portion of the image bearing member surface reaches a developing area in which the image bearing member and the developer bearing member are set against each other, and from among the areas on the image bearing member in which the charging is not yet performed in each image forming part, in case each area having passed the developing area when the developing bias is applied is brought into contact with the intermediate transfer member, the contact area with each area in the intermediate transfer member is controlled without superposing on the intermediate transfer member. | 03-12-2009 |
20090285607 | DEVELOPING APPARATUS - A developing apparatus including a first development sleeve carrying a developer toward a first development area, a second development sleeve carrying the developer from the first sleeve toward a second development area, a first magnet roller disposed in the first sleeve and having a first magnetic pole, a second magnet roller disposed in the second sleeve and having a second magnetic pole, a first magnet member disposed in the vicinity of an axial end of the first sleeve without facing the first magnetic pole, and a second magnet member disposed in the vicinity of an axial end of the second sleeve without facing the second magnetic pole. A surface facing the second sleeve in an end area downstream of the second magnet member in a rotating direction of the second developer carrying member is identical in polarity with the second magnetic pole. | 11-19-2009 |
20100061773 | DEVELOPING APPARATUS - A developing apparatus in which a first magnet of a first developing sleeve includes a first magnetic pole near a potion opposing to an image bearing member, and a second magnetic pole being downstream of the first magnetic pole; and a second magnet of a second developing sleeve includes a third magnetic pole near a portion opposing to the first sleeve. Assuming that a magnetic force obtained by combining normal direction forces Fr | 03-11-2010 |
20110052233 | DEVELOPMENT APPARATUS - In a development apparatus including conveying screws which circulates and conveys developer in a developer container as being rotated, a developing sleeve which bears and conveys developer in the developer container as being rotated, and a restriction blade which restricts developer quantity at the developing sleeve, the developer container includes a supply chamber to supply developer to the developing sleeve and a retrieval chamber to retrieve developer from the developing sleeve, and rotation speed of the conveying screws or rotation speed of the developing sleeve is changed so that Vsc/Vsl during image forming is not performed is to be smaller than that during image forming is performed, as Vsc denotes the rotation speed of the conveying screws and Vsl denotes the rotation speed of the developing sleeve. | 03-03-2011 |
20110170916 | DEVELOPING APPARATUS - A repulsive magnetic field is formed in a section immediately upstream of a regulating blade, so that generation of a developing-agent stationary layer is suppressed or eliminated. Accordingly, a developing apparatus capable of stably maintaining the layer thickness of developing agent conveyed to a developing area for a long time is provided. | 07-14-2011 |
20120201577 | DEVELOPING APPARATUS - A developing apparatus includes a developer carrying member; and a magnetic member provided inside the carrying member and having magnetic poles arranged circumferentially, wherein on a center axis of the carrying member outside an end of the magnetic member, there is a region in which a magnetic flux density of a first magnetic polarity converges toward zero; and wherein a ratio of a volume, per unit length, of a portion of the magnetic member which has a surface magnetic pole of a second magnetic polarity which is different from the first magnetic polarity in a longitudinal end portion to that in a longitudinally central portion is smaller than a ratio of a volume of a portion of the magnetic member which has a surface magnetic pole of the first magnetic polarity in a longitudinal end portion to that in a longitudinally central portion. | 08-09-2012 |
20120321352 | DEVELOPING APPARATUS - A developing apparatus is provided in which, with reference to a middle position in a developer conveyance direction, an average friction coefficient between an inner wall of the developing chamber and the developer, is smaller at an upstream side than at a downstream side in the developer conveyance direction. | 12-20-2012 |
20130136506 | DEVELOPING DEVICE - A developing device includes first and second developer carrying members for developing an electrostatic latent image formed on an image bearing member. The first developer carrying member has a surface provided with grooves and feeds a developer carried thereon to a first developing region which is an opposing portion where the first developer carrying member opposes the image bearing member. The second developer carrying member carries the developer delivered from the first developer carrying member and feeds the developer to a second developing region which is an opposing portion where the second developer carrying member opposes the image bearing member. The second developer carrying member has a surface provided with grooves different in angle from those of the surface of the first developer carrying member. | 05-30-2013 |
20130243489 | DEVELOPING APPARATUS - A developing apparatus, including: a developing sleeve; a magnet configured to cause the sleeve to carry the developer and including a first magnetic pole and a second magnetic pole; a supply chamber configured to supply the developer to the sleeve; a collection chamber configured to collect the developer used for development; a first conveyance member and a second conveyance member provided in the supply chamber and the collection chamber, respectively; and a third conveyance member configured to convey the developer collected in the collection chamber in a direction opposite to a developer conveying direction in the collection chamber, wherein a center of the third conveyance member is arranged below a zone and overlaps the zone, which is defined on a surface of the sleeve between a local maximal peak of a magnetic flux density of the first magnetic pole and a local minimal peak of the magnetic flux density. | 09-19-2013 |
20150037073 | DEVELOPING APPARATUS - A developing apparatus includes a developer carrying sleeve for carrying a developer to a position opposing an image bearing drum, wherein said sleeve is provided with a plurality of groove portions extending in an axial direction of said sleeve; and a developing bias voltage applying device for applying a developing bias voltage to said sleeve, wherein said bias voltage applying device is capable of outputting, as the bias voltage, a voltage of a waveform having a cyclic period including an AC bias portion comprising an AC component and a DC component superimposed thereto, and a blank portion following the AC bias portion and consisting of a DC component, wherein a width L (m) of the groove, a peripheral speed Vs (m/s) of said sleeve, and a duration t1 (s) of the blank portion in one cyclic period of the bias voltage satisfy L/Vs02-05-2015 | |