Abstract: An image forming device including an image carrier, a charge device, a developer device, power supply circuitry that applies a charge bias and a developer bias to the charge device and the developer device, respectively, a detector, and a hardware processor that operates as: a control unit that changes a fogging margin, which is a difference between charge bias and developer bias, and controls the power supply circuitry to set the charge bias and developer bias accordingly; a calculation unit that calculates amounts of change between detected values; and a determination unit that obtains differences between amounts of change, determines whether each difference is less than a defined value, and determines a position of a boundary between a first range greater than or equal to the defined value and a second range less than the defined value as a fogging margin to be used in forming a print image.

Abstract: An image forming device including an image carrier, a charge device, a developer device, power supply circuitry that applies a charge bias and a developer bias to the charge device and the developer device, respectively, a detector, and a hardware processor that operates as: a control unit that changes a fogging margin, which is a difference between charge bias and developer bias, and controls the power supply circuitry to set the charge bias and developer bias accordingly; a calculation unit that calculates amounts of change between detected values; and a determination unit that obtains differences between amounts of change, determines whether each difference is less than a defined value, and determines a position of a boundary between a first range greater than or equal to the defined value and a second range less than the defined value as a fogging margin to be used in forming a print image.

Abstract: An image forming apparatus includes: a job acquirer that acquires a print job; a photoconductor including a surface on which a toner image is to be formed; an electrifying member that electrifies the photoconductor; an exposure member that exposes the photoconductor; a developing member that supplies toner to the photoconductor; a cleaner that cleans the photoconductor; and a controller connected to the job acquirer to control the image forming apparatus, wherein the controller computes a first non-toner region that is provided on the surface of the photoconductor when the toner image is formed on the photoconductor, the first non-toner region not containing toner in a longitudinal direction of the surface of the photoconductor, and the controller causes the exposure member and the developing member to form the toner image on the photoconductor and to form a set of toner patches in the first non-toner region.

Abstract: A developing device, includes: a developing sleeve supported rotatably, the developing sleeve having a hollow, substantially cylindrical shape; a magnet part having a substantially columnar shape, the magnet part having magnetic poles disposed side by side around an axis, the magnet part being disposed substantially coaxially with the developing sleeve inside the developing sleeve; a rod fastened to the magnet part, the rod extending from one end in an extending direction of the axis of the magnet part, the rod being pulled out from one axial end of the developing sleeve; and a holder attached to a portion of the rod pulled out from the developing sleeve, the holder being fastened to a fastening target, the holder maintaining the rod, the holder regulating rotation of the magnet part, wherein adjustment of the holder in fastening position enables disposition and holding of the rod at an optional position.

Abstract: An image forming apparatus includes: a job acquirer that acquires a print job; a photoconductor including a surface on which a toner image is to be formed; an electrifying member that electrifies the photoconductor; an exposure member that exposes the photoconductor; a developing member that supplies toner to the photoconductor; a cleaner that cleans the photoconductor; and a controller connected to the job acquirer to control the image forming apparatus, wherein the controller computes a first non-toner region that is provided on the surface of the photoconductor when the toner image is formed on the photoconductor, the first non-toner region not containing toner in a longitudinal direction of the surface of the photoconductor, and the controller causes the exposure member and the developing member to form the toner image on the photoconductor and to form a set of toner patches in the first non-toner region.

Abstract: An image forming apparatus includes: an image carrier that rotates while carrying a toner image; an image former that forms the toner image; a transfer roller that transfers the toner image to a recording medium; and a bias voltage applier that applies a voltage to the transfer roller, wherein the image former forms transfer images and forms a patch image with toner between a first transfer image and a second transfer image, and the bias voltage applier applies a first voltage having a polarity opposite to a charge polarity of the toner to the transfer roller, applies a second voltage having the polarity opposite to the charge polarity of the toner and larger than the first voltage to the transfer roller, and applies a third voltage having the polarity opposite to the charge polarity of the toner and smaller than the second voltage to the transfer roller.

Abstract: An image forming apparatus includes: an image carrier that rotates while carrying a toner image; an image former that forms the toner image; a transfer roller that transfers the toner image to a recording medium; and a bias voltage applier that applies a voltage to the transfer roller, wherein the image former forms transfer images and forms a patch image with toner between a first transfer image and a second transfer image, and the bias voltage applier applies a first voltage having a polarity opposite to a charge polarity of the toner to the transfer roller, applies a second voltage having the polarity opposite to the charge polarity of the toner and larger than the first voltage to the transfer roller, and applies a third voltage having the polarity opposite to the charge polarity of the toner and smaller than the second voltage to the transfer roller.

Abstract: An image forming apparatus includes an image former which forms an image on an image carrying member with toner stored in a storage, a toner supplier which supplies toner to the storage by driving a conveyance member, a density measurer which causes the image former to form an image having a predetermined density at a predetermined timing and measures density of the formed image, a corrector which corrects a driving amount of the conveyance member based on the density measured by the density measurer, and a changer which changes a timing when the density measurer measures the density in response to an event that a predetermined condition is satisfied.

Abstract: An image forming apparatus includes an image former which forms an image on an image carrying member with toner stored in a storage, a toner supplier which supplies toner to the storage by driving a conveyance member, a density measurer which causes the image former to form an image having a predetermined density at a predetermined timing and measures density of the formed image, a corrector which corrects a driving amount of the conveyance member based on the density measured by the density measurer, and a changer which changes a timing when the density measurer measures the density in response to an event that a predetermined condition is satisfied.

Abstract: A developing device has a first circulation tank and a second circulation tank. A developer is conveyed from the first circulation tank to the second circulation tank through a first opening, while the developer is partly discharged through an outlet. The developer conveyed to the second circulation tank is conveyed back in the first circulation tank via a second opening. A first screw provided in the first circulation tank has a first vane, which exerts a force in a conveying direction of the first circulation path, in a first portion upstream from the first opening with respect to the conveying direction. The first screw has no vanes in a second portion near the first opening. The first screw has a second vane, which exerts a force in a direction opposite to the conveying direction, in a third portion adjacently downstream from the second portion. The outlet is located at a point of the first circulation tank, downstream from the second vane.

Abstract: A developing device has a first circulation tank and a second circulation tank. A developer is conveyed from the first circulation tank to the second circulation tank through a first opening, while the developer is partly discharged through an outlet. The developer conveyed to the second circulation tank is conveyed back in the first circulation tank via a second opening. A first screw provided in the first circulation tank has a first vane, which exerts a force in a conveying direction of the first circulation path, in a first portion upstream from the first opening with respect to the conveying direction. The first screw has no vanes in a second portion near the first opening. The first screw has a second vane, which exerts a force in a direction opposite to the conveying direction, in a third portion adjacently downstream from the second portion. The outlet is located at a point of the first circulation tank, downstream from the second vane.

Abstract: A developing device comprising: a first transport member disposed in a first transport passage and configured to rotate and thereby transport developer; a second transport member disposed in a second transport passage and configured to rotate and thereby transport the developer; and a developer carrier configured to carry the developer supplied from the first transport passage, wherein the second transport passage is composed of an upstream section and a downstream section, the second transport passage communicates with the first transport passage via a first communication passage and a second communication passage, the upstream section is configured to receive refill toner, and V1<V2<V3, where V1 denotes an average transport speed of the first transport member, V2 denotes an average transport speed of an upstream section of the second transport member, and V3 denotes an average transport speed of a downstream section of the second transport member.

Abstract: A developing device comprising: a first transport member disposed in a first transport passage and configured to rotate and thereby transport developer; a second transport member disposed in a second transport passage and configured to rotate and thereby transport the developer; and a developer carrier configured to carry the developer supplied from the first transport passage, wherein the second transport passage is composed of an upstream section and a downstream section, the second transport passage communicates with the first transport passage via a first communication passage and a second communication passage, the upstream section is configured to receive refill toner, and V1<V2<V3, where V1 denotes an average transport speed of the first transport member, V2 denotes an average transport speed of an upstream section of the second transport member, and V3 denotes an average transport speed of a downstream section of the second transport member.

Abstract: A development apparatus 8 has developer transport members 26 and 27 respectively contained in containers 22 and 23 and transporting developer while stirring the developer and passing the developer to each other at a passing portion 41 and a passing portion 42, thereby causing the developer to circulate in a developer tank 21. The passing portion 41 is formed at a location of a partition 21c adjacent to a developer discharging mechanism 34 and the passing portion 42 is formed at a location of the partition 21c away from the developer discharging mechanism 34. The passing portions 41 and 42 have configurations in which a transport force acting on the developer at the passing portion 41 is greater than the transport force acting on the developer at the passing portion 42.

Abstract: A development apparatus 8 has developer transport members 26 and 27 respectively contained in containers 22 and 23 and transporting developer while stirring the developer and passing the developer to each other at a passing portion 41 and a passing portion 42, thereby causing the developer to circulate in a developer tank 21. The passing portion is formed at a location of a partition 21c adjacent to a developer discharging mechanism 34 and the passing portion 42 is formed at a location of the partition 21c away from the developer discharging mechanism 34. The passing portions 41 and 42 have configurations in which a transport force acting on the developer at the passing portion 41 is greater than the transport force acting on the developer at the passing portion 42.

Abstract: A charging device has a discharging electrode, a stabilizer plate having a rectangular section and accommodating the discharging electrode, and a grid arranged in a opening of the stabilizer plate, and at least one member of the discharging electrode, the stabilizer plate and the grid is made of an electrically conductive material containing 30% or more of nickel by weight or is plated with nickel or platinum at a rate from 30% to 80% by weight with respect to whole weight of the plated member. An image forming apparatus employs the charging device.

Abstract: A charging device has a discharging electrode, a stabilizer plate having a rectangular section and accommodating the discharging electrode, and a grid arranged in a opening of the stabilizer plate, and at least one member of the discharging electrode, the stabilizer plate and the grid is made of an electrically conductive material containing 30% or more of nickel by weight or is plated with nickel or platinum at a rate from 30% to 80% by weight with respect to whole weight of the plated member. An image forming apparatus employs the charging device.

Abstract: A charging member is disposed so as to contact a surface of a charge-receiving member which moves relative to the charging member. In conjunction with the movement of the charge receiving member, the charging member removes foreign substance present on the charge-receiving member on the upstream side in the direction of travel of the charge-receiving member at the contact region with the charging member. Simultaneously, a discharge voltage is applied to the charging member so that the charging member charges the charge-receiving member in the area from which said foreign substance has been removed at the contact region on the downstream side of the charge-receiving member in the direction of travel of the charge-receiving member. During a cleaning operation, the charging member retracts from the charge-receiving member and is out of contact therewith in accordance with the number of image formations, black and white ratio, and humidity.

Abstract: A charging device K is provided with a flexible electrode 12 and a flexible intermediate member M disposed between the flexible electrode 12 and a charge-receiving member 10, with the flexible intermediate member M being in contact with the charge-receiving member 10. The flexible intermediate member M includes a flexible insulated member 11 and semiconductive member 14 so as to charge the charge-receiving member 10 via a discharge from electrode 12. The absolute value of the difference between the potential of the flexible electrode 12 during discharge and the potential in the vicinity of at least the area of discharge of the flexible electrode 12 among areas in which the flexible intermediate member is in contact with the charge-receiving member 10, is less than the absolute value of the difference between the potential of the charge-receiving member and the potential of the flexible electrode during discharge.

Abstract: An image forming apparatus and a cleaning blade employed in the image forming apparatus which is operable to form an electrostatic latent image on an image carrying member, develop the latent image with toner into a visible toner image, transfer the toner image onto a record member and fix the same, and having an edge pressed against the image carrying member with a predetermined pressure for removing residual toner on the image carrying member after the transfer. A degree of toluene swelling of the cleaning blade is in a range from 20% to 100%, and the cleaning blade has an impact resilience in a range from 10% to 65%, a Young's modulus in a range from 30 to 120 kg/cm.sup.2, and a 300%-modulus in a range from 100 to 600 kg/cm.sup.2.