Abstract: An image forming apparatus includes: an image forming unit configured to form an image pattern on a medium, a predetermined image repeatedly appearing in a first cycle in a sub scanning direction in the image pattern; a density detector configured to optically detect a density of the image pattern in the sub scanning direction; a cyclic image detector configured to detect a feature image having a second cycle corresponding to the first cycle in accordance with a result of the detection; and a state determining unit configured to determine whether a cycle depending on an outer circumference of a rotary member included in the image forming apparatus corresponds to the second cycle when the feature image is detected by the cyclic image detector, and determine that a state of the rotary member has deteriorated when the cycle depending on the outer circumference is determined to correspond to the second cycle.

Abstract: An image forming apparatus includes: an image forming unit configured to form an image pattern on a medium, a predetermined image repeatedly appearing in a first cycle in a sub scanning direction in the image pattern; a density detector configured to optically detect a density of the image pattern in the sub scanning direction; a cyclic image detector configured to detect a feature image having a second cycle corresponding to the first cycle in accordance with a result of the detection; and a state determining unit configured to determine whether a cycle depending on an outer circumference of a rotary member included in the image forming apparatus corresponds to the second cycle when the feature image is detected by the cyclic image detector, and determine that a state of the rotary member has deteriorated when the cycle depending on the outer circumference is determined to correspond to the second cycle.

Abstract: An image forming apparatus including: a photoreceptor; a charger configured to charge a photoreceptor surface; an optical scanning device configured to expose the photoreceptor surface to form an electrostatic latent image thereon; a developing device configured to develop the electrostatic latent image to form a toner image thereon; a transfer member configured to transfer the toner image to a sheet; a fixing device configured to fix the toner image thereon; and a control unit configured to carry out exposure amount control for formation of an image having a pattern with a spatial frequency from 0.1 c/mm to 3.0 c/mm so that after the exposure, there will be an electric potential difference V1 between an edge portion and a non-edge portion of the pattern and so that there will be an electric potential difference V2 larger than V1 between an edge-surrounding portion and the other portions of a non-image area.

Abstract: An image forming apparatus includes an image bearing body, a latent image forming section that forms a latent image on the image bearing body, a development section that develops the latent image using toner, a transfer section that transfers a toner image to a transferred body, a pressuring and contacting section that pressures and contact the transfer section against and with the image bearing body via the transferred body, a cleaning blade that removes residual toner, and a controller. The controller analyzes a print pattern of the image to be formed on the sheet. The controller controls the pressuring and contacting section to change a contact state between the image bearing body and the transferred body while adjusting an image patch formed in a domain corresponding to an inter-sheet portion between the sheet and the next sheet on the image bearing body according to an analysis result.

Abstract: An image forming apparatus including: a photoreceptor; a charger configured to charge a photoreceptor surface; an optical scanning device configured to expose the photoreceptor surface to form an electrostatic latent image thereon; a developing device configured to develop the electrostatic latent image to form a toner image thereon; a transfer member configured to transfer the toner image to a sheet; a fixing device configured to fix the toner image thereon; and a control unit configured to carry out exposure amount control for formation of an image having a pattern with a spatial frequency from 0.1 c/mm to 3.0 c/mm so that after the exposure, there will be an electric potential difference V1 between an edge portion and a non-edge portion of the pattern and so that there will be an electric potential difference V2 larger than V1 between an edge-surrounding portion and the other portions of a non-image area.

Abstract: A cleaning roller has a core and a polyurethane foam layer covering the core to form a peripheral surface of the cleaning roller adapted to be in contact with a peripheral surface of the toner image bearing member. The polyurethane foam is designed so that the number of cell per inch thereof is 30 or more and 60 or less and an open ratio of cell walls thereof is 3% or more and 50% or less.

Abstract: An image forming apparatus includes an image bearing body, a latent image forming section that forms a latent image on the image bearing body, a development section that develops the latent image using toner, a transfer section that transfers a toner image to a transferred body, a pressuring and contacting section that pressures and contact the transfer section against and with the image bearing body via the transferred body, a cleaning blade that removes residual toner, and a controller. The controller analyzes a print pattern of the image to be formed on the sheet. The controller controls the pressuring and contacting section to change a contact state between the image bearing body and the transferred body while adjusting an image patch formed in a domain corresponding to an inter-sheet portion between the sheet and the next sheet on the image bearing body according to an analysis result.

Abstract: Image forming apparatus to expose-scan electrically charged surface of image carrier based on image data in unit of page to form electrostatic latent image, and develop electrostatic latent image at development position on image carrier by using developer carried by developer carrier. The image forming apparatus determines, based on image data of page, first and second partial regions having first and second attributes in page, not overlapping in sub scanning direction, and switches development bias voltage value and/or rotational speed of developer carrier to value for first attribute while electrostatic latent image on image carrier corresponding to first partial region passes through development position, and to value for second attribute while electrostatic latent image corresponding to second partial region passes through development position.

Abstract: A cleaning roller for cleaning a charging roller in an image forming apparatus is disposed in contact with an outer peripheral surface of a charging roller to remove foreign matters attached to the outer peripheral surface of the charging roller. The cleaning roller has a metal core and a polyurethane foam layer covering an outer peripheral surface of this metal core. The polyurethane foam layer includes a number of cells. The number of cells per inch is 40 or more and 80 or less, and an open ratio of a wall surface of cells is 3% or more and 50% or less.

Abstract: An intermediate transfer belt has an elastic layer and a modified layer formed by a surface-modifying treatment of a surface of the elastic layer, wherein the surface of the elastic layer with the modified layer has a surface hardness of 0.01 GPa or more and exhibits 50 nm or more of displacement at the time of pushing the surface at a load of 20 ?N by means of a cube corner tip having a tip sharp angle of 90 degree.

Abstract: A developing device of an electrophotographic image forming apparatus has a first roller and a second roller disposed in a peripheral contact with the first roller to define a contact region therebetween so that the first roller is capable of supplying and collecting a toner to and from the second roller in the contact region. The first roller has a core and a polyurethane foam layer. The polyurethane foam has an open ratio of cells of 2% or more and 50% or less and a hardness of 1 gf/mm or more and 6 gf/mm or less, the hardness being defined by a load per unit length in a longitudinal direction of the first roller, the load being determined by forcing the peripheral surface of the polyurethane foam layer against a substrate, measuring a load necessary for the polyurethane foam layer to be compressed by 30% in thickness, and dividing the load by a length of the polyurethane foam layer in the longitudinal direction.

Abstract: A developing device has a developer bearing member, a housing adapted to accommodate a developer, and a supply roller adapted to supply the developer within the housing for the developer bearing member. The supply roller has an outer circumferencial foam layer made of resin or rubber. The foam layer has an air permeability of 150-200 ml/cm2/s, a hardness of 50-200 N, and an average cell density of 20-40 per 25 mm width.

Abstract: A developing roller has a surface layer composed of a binder resin having an SP value in the range of 7.5 to 9.0, and roughness-imparting particles made from a resin having an SP value that has a difference from the SP value of the resin of 2 or less in the absolute value thereof. The roughness-imparting particles are dispersed in the binder resin. A developing device is provided with the developing roller. An image-forming apparatus is provided with the developing device equipped with the developing roller.

Abstract: An image forming apparatus has an electrostatic latent image bearing member capable of bearing an electrostatic latent image thereon, and a developer apparatus having a developer material for visualizing the electrostatic latent image into a visualized image. The developer apparatus includes a developer material bearing member, a housing adapted to accommodate a developer material, and a supply roller adapted to supply the developer material within the housing for the developer material bearing member. The supply roller has an outer circumferential foam layer. The foam layer is made of resin foam or rubber foam and has an air permeability of 5 ml/cm2/s or less, a density of 50-200 kg/m3, and a hysteresis loss ratio of 35-45%.

Abstract: A cleaning roller has a core and a polyurethane foam layer covering the core to form a peripheral surface of the cleaning roller adapted to be in contact with a peripheral surface of the toner image bearing member. The polyurethane foam is designed so that the number of cell per inch thereof is 30 or more and 60 or less and an open ratio of cell walls thereof is 3% or more and 50% or less.

Abstract: A developing device of an electrophotographic image forming apparatus has a first roller and a second roller disposed in a peripheral contact with the first roller to define a contact region therebetween so that the first roller is capable of supplying and collecting a toner to and from the second roller in the contact region. The first roller has a core and a polyurethane foam layer. The polyurethane foam has an open ratio of cells of 2% or more and 50% or less and a hardness of 1 gf/mm or more and 6 gf/mm or less, the hardness being defined by a load per unit length in a longitudinal direction of the first roller, the load being determined by forcing the peripheral surface of the polyurethane foam layer against a substrate, measuring a load necessary for the polyurethane foam layer to be compressed by 30% in thickness, and dividing the load by a length of the polyurethane foam layer in the longitudinal direction.

Abstract: A cleaning roller for cleaning a charging roller in an image forming apparatus is disposed in contact with an outer peripheral surface of a charging roller to remove foreign matters attached to the outer peripheral surface of the charging roller. The cleaning roller has a metal core and a polyurethane foam layer covering an outer peripheral surface of this metal core. The polyurethane foam layer includes a number of cells. The number of cells per inch is 40 or more and 80 or less, and an open ratio of a wall surface of cells is 3% or more and 50% or less.

Abstract: A developing roller, having a surface layer composed of; a binder resin having an SP value in the range of 7.5 to 9.0; and roughness-imparting particles made from a resin having an SP value that has a difference from the SP value of said resin of 2 or less in the absolute value thereof, the roughness-imparting particles being dispersed in the binder resin, a developing device provided with the developing roller and an image-forming apparatus provided with such a developing device, a developing device provided with the developing roller, and an image-forming apparatus provided with the developing device equipped with the developing roller.

Abstract: A developing device has a developer bearing member, a housing adapted to accommodate a developer, and a supply roller adapted to supply the developer within the housing for the developer bearing member. The supply roller has an outer circumferencial foam layer made of resin or rubber. The foam layer has an air permeability of 150-200 ml/cm2/s, a hardness of 50-200 N, and an average cell density of 20-40 per 25 mm width.

Abstract: An image forming apparatus has an electrostatic latent image bearing member capable of bearing an electrostatic latent image thereon, and a developer apparatus having a developer material for visualizing the electrostatic latent image into a visualized image. The developer apparatus includes a developer material bearing member, a housing adapted to accommodate a developer material, and a supply roller adapted to supply the developer material within the housing for the developer material bearing member. The supply roller has an outer circumferencial foam layer. The foam layer is made of resin foam or rubber foam and has an air permeability of 5 ml/cm2/s or less, a density of 50-200 kg/m3, and a hysteresis loss ratio of 35-45 %.