Patent application number | Description | Published |
20080226320 | DEVELOPING UNIT AND IMAGE FORMING APPARATUS - A developing unit has a voltage-applicator ( | 09-18-2008 |
20080232859 | IMAGE FORMING APPARATUS - An image forming apparatus has a photoconductive member on which a latent image is to be formed, a developing roller for developing the latent image on the photoconductive member by a first bias. A magnetic roller forms a magnetic brush thereon with a two-component developer and forms a thin toner layer on the developing roller by a second bias. The developing roller is aluminum with a surface treated for high resistance. The thickness (T) of the toner layer and the duty ratio (D | 09-25-2008 |
20080232862 | IMAGE FORMING APPARATUS - An image forming apparatus has a photoconductive member, and a developing roller develops a latent image on the photoconductive member by a first alternating-current bias in the form of a rectangular wave. The following relationships are satisfied in calculating the duty ratio (D | 09-25-2008 |
20080292365 | IMAGE FORMING APPARATUS AND DEVELOPING DEVICE - An image forming apparatus is characterized in that an absolute value of a difference between a first coefficient of variation in a number distribution of the particle diameter of a toner carried on a developing roller and a second coefficient of variation in a number distribution of the particle diameter of a toner in a two-component developer carried on the magnetic roller is within 5% and an absolute value of a difference between a third coefficient of variation in a number distribution of the particle diameter of a toner of a toner image developed on the outer surface of an image bearing member and the second coefficient of variation is within 6%. With such an image forming apparatus, high-quality images can be stably formed over a long term. | 11-27-2008 |
20080298847 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device uses a two-component developer including at least carriers and toners. The toners are supplied to an image bearing member bearing an electrostatic latent image so that a toner image is developed from the electrostatic latent image. The developing device has a developing roller arranged to oppose the image bearing member; and a magnetic roller arranged to oppose the developing roller. The magnetic roller retains the two-component developer to supply toners to the developing roller. The developing roller and the magnetic roller are rotationally driven in directions to be opposite from one another at an opposed position, and a magnetic pole of the magnetic roller and a magnetic pole of the developing roller have magnetic polarities different from one another at the opposed position. A surface roughness of the magnetic roller is greater than a surface roughness of the developing roller. | 12-04-2008 |
20090003891 | IMAGE FORMING APPARATUS - An image forming apparatus uses a two-component developer containing a toner and a carrier. The apparatus has a latent image bearer for bearing an electrostatic latent image. A toner bearer bears the toner to be conveyed to a development region to develop the electrostatic latent image. A developer bearer bears the two-component developer and supplies the toner to the toner bearer. A regulator sets the thickness of a toner layer carried on the toner bearer to 6 μm to 15 μm and sets a difference between a half width of a first toner charge number distribution as a number distribution of the charge amount of the toner carried on the toner bearer and that of a second toner charge number distribution as a number distribution of the charge amount of the toner in the two-component developer carried on the developer bearer to 0.8 (10 | 01-01-2009 |
20090154962 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device visualizing an electrostatic latent image previously formed on the surface of an image carrier as toner image, comprising: a developing roller placed at a position facing the image carrier, carrying a toner on the surface thereof, conveying the toner and flying the conveyed toner onto the surface of the image carrier; and a resin layer coated on the surface of the developing roller, wherein the absolute value of the difference in charge between the toners in the upper and lower layers of the toner layer formed on the developing roller as the toner carried on the developing roller is 6 μC/g or less. | 06-18-2009 |
20090290912 | DEVELOPER APPARATUS AND IMAGE FORMING APPARATUS COMPRISING THE SAME - A developer includes a developer carrying body that carries a two-component developer having a magnetic toner and a carrier. A toner carrying body opposes the developer carrying body and receives toner from the developer carrying body. An image carrying body develops an electrostatic latent image by toner carried on the toner carrying body. A first magnetic member is inside the developer carrying body and opposes a surface of the toner carrying body. A second magnetic member is inside the toner carrying body and opposes the surface of the developer carrying body. The second magnetic member is magnetized to an opposite polarity to the first magnetic member and generates a magnetic force at least on the surface of the toner carrying body in a range of 25 mT to 40 mT in a direction perpendicular to the surface of the toner carrying body. | 11-26-2009 |
20130022365 | IMAGE FORMING APPARATUS CAPABLE OF PRINTING LONG SHEETS - An image forming apparatus includes a separating unit for performing a stripping operation of forcibly returning toner particles carried on a toner bearing member to a developer bearing member, a sheet size discriminator for discriminating whether a sheet is a standard sized sheet or a long sheet, a determiner for determining whether or not there is any blank area of a predetermined length or longer in the sub scanning direction, where no toner image is to be substantially transferred, for each long sheet, and a controller for controlling the stripping operation. The controller causes the separating unit to perform the stripping operation at a developing timing of an electrostatic latent image corresponding to the blank area to be formed on the image bearing member when the sheet is a long sheet and when the blank area of the predetermined length or longer is present. | 01-24-2013 |
20130243454 | IMAGE FORMING APPARATUS CAPABLE OF PRINTING LONG SHEETS - In the case of a standard sized sheet, a first controller sets a linear velocity D of an image bearing member at a first velocity and sets a linear velocity S of a toner bearing member so that S/D, which is a ratio of the linear velocity S to the linear velocity D, has a first value and a second controller sets the thickness of the toner layer carried on the toner bearing member at a first layer thickness. In the case of a long sheet, the first controller sets the linear velocity D at a second velocity slower than the first velocity and sets the linear velocity S so that the S/D has a second value larger than the first value and the second controller sets the thickness of the toner layer at a second layer thickness smaller than the first layer thickness. | 09-19-2013 |