Abstract: An image forming apparatus includes an image carrying member, a charging device, an exposure device, a developing device, a development voltage power supply, and a control section. The developing device includes a development container for containing a non-magnetic one-component developer composed only of a toner, a developer carrying member having an outer circumferential surface on which a toner layer is formed, and a toner supply member that supplies the toner to the developer carrying member. The control section performs control so that, as a cumulative drive time of the developing device increases, a supply voltage Vsdc becomes larger than a reference supply voltage and a development voltage Vdc becomes smaller than a reference development voltage, thus executing control to vary the development voltage Vdc and the supply voltage Vsdc so as to increase a potential difference Vsdc?Vdc between the supply voltage Vsdc and the development voltage Vdc.

Abstract: An image forming apparatus includes an image carrying member, a charging device, an exposure device, a developing device, and a control section. The developing device includes a development container for containing a non-magnetic one-component developer composed only of a toner, a developer carrying member having an outer circumferential surface on which a toner layer is formed, and a regulation blade that regulates a thickness of the toner layer. The control section executes speed reduction control to reduce a rotation speed of the developer carrying member at a time of warming-up before image formation to a first speed lower than a reference speed at a time of the image formation. In the speed reduction control, the control section raises the rotation speed of the developer carrying member at a first acceleration rate until the first speed is reached from a state where rotation of the developer carrying member is stopped.

Abstract: An image forming apparatus includes an image carrying member, a charging device, an exposure device, a developing device, a control section, and a temperature detecting device. The developing device includes a developer carrying member having an outer circumferential surface on which a toner layer is formed, and a regulation blade that regulates a thickness of the toner layer. The control section executes speed reduction control to reduce a rotation speed of the developer carrying member at a time of warming-up. When a printing operation to be performed after the warming-up is intermittent printing and an interval of the intermittent printing is not less than a prescribed time or a temperature detected by the temperature detecting device is not more than a prescribed temperature, the control section reduces the rotation speed of the developer carrying member in the speed reduction control to a second speed lower than the first speed.

Abstract: A developing device includes a development container, a toner carrier, and a regulation blade. The toner carrier supplies toner contained in the development container to an image carrier in a facing region between the toner carrier and the image carrier. The regulation blade contacts the toner carrier on an upstream side of the facing region in a rotation direction of the toner carrier, and regulates a thickness of a layer of the toner carried on the toner carrier. The regulation blade is formed of a metal material polished in a direction same as a toner moving direction in a contact region between the regulation blade and the toner carrier such that an arithmetic average roughness of a surface of the regulation blade is 0.3 ?m or less.

Abstract: An image forming device includes photoconductor drum that rotates around axis and has drum circumferential face on which electrostatic latent image is formed, and developing unit that supplies developer to photoconductor drum thereby to manifest electrostatic latent image into developer image. The developing unit includes developing housing, developing roller supported by developing housing to be rotatable around axis, has first circumferential face that faces drum circumferential face and carries developer, and supplies carried developer to drum circumferential face, and restricting blade that contacts first circumferential face, and restricts amount of developer to be carried on first circumferential face, and first circumferential face has value of 4.

Abstract: An image forming apparatus includes an image carrier, a charger, an exposure device, a development device and a pressing mechanism. The developer carrier is pressed on the image carrier with a predetermined pressing force to form a nip area between the roller part and the image carrier. A roller part of the developer carrier has an Asker C hardness of 65° or more and 73° or less. When the pressing force is set to X (N) and a width of the nip area in a circumferential direction of the image carrier is set to Y (?m), 3.0?X?8.0 and 550?Y?700, and the following expressions (1) and (2) are satisfied, Y ? 31. X + 393.2 ? and , ( 1 ) Y ? 47. X + 450.1 .

Abstract: An image forming apparatus includes an image carrier, a charger, an exposure device, a development device and a pressing mechanism. When a developer carrier and the image carrier are rotated in a state where a film is held in a development nip area and then a pulling force of the film is measured, a maximum value MAX, a minimum value MIN, and an average value X of the pulling force satisfy the expressions (1) and (2). When a development voltage applied to the developer carrier is set to Vdc, the surface potential of the image carrier is set to V0, and the surface potential of the image carrier after exposure is set to VL, the expressions (3) and (4) are satisfied. X?MAX?1.5X??(1), 0.5X?MIN?X??(2), V0?Vdc?2(Vdc?VL)??(3) and Vdc?VL?100??(4).

Abstract: A development device includes a development housing, a development roller, a supply roller and a layer thickness regulating member. The development housing stores a nonmagnetic one-component toner. The development roller is formed by a cylindrical elastic body, and moves in a same direction as a rotational direction of a rotatable photosensitive drum at a development nip area while coming into contact with the photosensitive drum. The supply roller is formed by a cylindrical elastic body, and supplies the toner to the development roller and collects the toner from the development roller. The development roller has a surface free energy within a range of 5 mJ/m2 or more and 27 mJ/m2 or less.

Abstract: An image forming apparatus includes an image carrier, a charger, an exposure device, a development device and a pressing mechanism. When a developer carrier and the image carrier are rotated in a state where a film is held in a development nip area and then a pulling force of the film is measured, a maximum value MAX, a minimum value MIN, and an average value X of the pulling force satisfy the expressions (1) and (2). When a development voltage applied to the developer carrier is set to Vdc, the surface potential of the image carrier is set to V0, and the surface potential of the image carrier after exposure is set to VL, the expressions (3) and (4) are satisfied. X?MAX?1.5X??(1), 0.5X?MIN?X??(2), V0?Vdc?2(Vdc?VL)??(3) and Vdc?VL?100??(4).

Abstract: A development device includes a development container, a developer carrier, a regulating blade. The development container contains a non-magnetic one-component developer consisting of a toner only. The regulating blade has a curved part having a radius of curvature of 0.1 mm or more and coming into contact with the roller part. The curved part has an arithmetic average roughness Ra of 0.05 to 0.3 ?m. The roller part has a ten-point average roughness Rz of 2 to 4 ?m. The roller part has a concave and convex portion, and an average interval Sm between the concave portion and the convex portion is 120 to 290 ?m. A Sm/Rz is 30 to 145. A width of a nip area between the regulating blade and the roller part in a circumferential direction of the roller part is 0.1 to 0.95 mm.

Abstract: An image forming apparatus includes an image carrier, a charger, an exposure device, a development device and a pressing mechanism. The developer carrier is pressed on the image carrier with a predetermined pressing force to form a nip area between the roller part and the image carrier. A roller part of the developer carrier has an Asker C hardness of 65° or more and 73° or less. When the pressing force is set to X (N) and a width of the nip area in a circumferential direction of the image carrier is set to Y (?m), 3.0?X?8.0 and 550?Y?700, and the following expressions (1) and (2) are satisfied, Y ? 31.0 ? ? X + 393.2 ? ? and , ( 1 ) Y ? 47.0 ? X + 450.1 .

Abstract: An image forming apparatus includes an image-carrying member, a charging device, an exposure device, and a developing device. The charging device charges a surface of the image-carrying member. The exposure device writes an electrostatic latent image on the surface of the image-carrying member by exposing the charged surface of the image-carrying member. The developing device includes a developing roller and a bias output circuit. The bias output circuit applies a developing bias to the developing roller. A potential VH of a non-exposure portion charged on the surface of the image-carrying member, a potential VL of an exposure portion on the surface of the image-carrying member, and the developing bias VDD meet a relationship of VH?VDD?2 (VDD?VL). In addition, a difference between the developing bias VDD and the potential VL of the exposure portion (VDD?VL) is 100 V or more.

Abstract: A development device includes a development housing, a development roller, a supply roller and a layer thickness regulating member. The development housing stores a nonmagnetic one-component toner. The development roller is formed by a cylindrical elastic body, and moves in a same direction as a rotational direction of a rotatable photosensitive drum at a development nip area while coming into contact with the photosensitive drum. The supply roller is formed by a cylindrical elastic body, and supplies the toner to the development roller and collects the toner from the development roller. The development roller has a surface free energy within a range of 5 mJ/m2 or more and 27 mJ/m2 or less.

Abstract: An image forming apparatus includes a housing in which a developing device is disposed, a cover member attached to the housing, a developer storage container to be detachably attached to the developing device, and a sensor unit. The developer storage container includes a container body having a storage space for storing a developer and a developer discharge port, and a moving wall configured to move in the container body. The sensor unit is arranged at a detection position where a detection sensor faces a specific area located above the developer discharge port on an outer peripheral surface of the container body when the cover member is in a closing posture, and arranged at a detection disable position where the detection sensor is distant from the specific area when the cover member is in an opening posture.

Abstract: A developer container includes a container main body having an internal space and a developer discharge port; a movable wall moving in the internal space toward the developer discharge port; a detection surface which is a part of an inner peripheral surface that divides a storage space of a developer in the container main body and which becomes a detection region of a first detection sensor which detects the developer in the storage space; and a rotating body arranged in the storage space and capable of rotating around a rotary shaft along the first direction. The rotating body is mounted with a cleaning member which cleans the detection surface, a stirring member which stirs a developer in the storage space, and a detection target member to be a detection target of a second detection sensor which detects presence of the container main body.

Abstract: An image forming apparatus includes a housing in which a developing device is disposed, a cover member attached to the housing, a developer storage container to be detachably attached to the developing device, and a sensor unit. The developer storage container includes a container body having a storage space for storing a developer and a developer discharge port, and a moving wall configured to move in the container body. The sensor unit is arranged at a detection position where a detection sensor faces a specific area located above the developer discharge port on an outer peripheral surface of the container body when the cover member is in a closing posture, and arranged at a detection disable position where the detection sensor is distant from the specified area when the cover member is in an opening posture.

Abstract: An image forming apparatus includes a developer container having a movable wall therein, a determination unit, a movable wall driving unit, and a movable wall driving controller. The determination unit outputs first determination information when a number of outputs of a signal indicating that a detection sensor has detected a developer is less than a threshold value, and outputs second determination information when the number of outputs thereof is equal to or greater than the threshold value. The movable wall driving unit includes a first driving motor for moving the movable wall and a first driving circuit for controlling driving thereof. The movable wall driving controller includes a signal controller. The signal controller transmits a drive permission signal for the first driving motor when the first determination information is output, and transmits a drive non-permission signal for the first driving motor when the second determination information is output.

Abstract: A developer container includes a container main body having an internal space and a developer discharge port; a movable wall moving in the internal space toward the developer discharge port; a detection surface which is a part of an inner peripheral surface that divides a storage space of a developer in the container main body and which becomes a detection region of a first detection sensor which detects the developer in the storage space; and a rotating body arranged in the storage space and capable of rotating around a rotary shaft along the first direction. The rotating body is mounted with a cleaning member which cleans the detection surface, a stirring member which stirs a developer in the storage space, and a detection target member to be a detection target of a second detection sensor which detects presence of the container main body.

Abstract: An image forming apparatus includes a developer container having a movable wall therein, a determination unit, a movable wall driving unit, and a movable wall driving controller. The determination unit outputs first determination information when a number of outputs of a signal indicating that a detection sensor has detected a developer is less than a threshold value, and outputs second determination information when the number of outputs thereof is equal to or greater than the threshold value. The movable wall driving unit includes a first driving motor for moving the movable wall and a first driving circuit for controlling driving thereof. The movable wall driving controller includes a signal controller. The signal controller transmits a drive permission signal for the first driving motor when the first determination information is output, and transmits a drive non-permission signal for the first driving motor when the second determination information is output.

Abstract: A developing device includes a housing, a developing roller, a developer conveyance path, a partition plate, a developer supply port and a developer conveying member. The developer conveying member rotates such that an outer peripheral part thereof moves from top to bottom in a first area between a second shaft portion and the partition plate and moves from bottom to top in a second area between the second shaft portion and the side wall. The developer supply port is obliquely open above the second area. The housing includes a first space formed above the second area of the first conveyance path and a second space formed up to a position higher than the partition plate to communicate with the first conveyance path above the first area of the first conveyance path and communicating with the first space in a horizontal direction.