Abstract: A charging roller includes a surface layer containing first and second surface particles and satisfying the following: 6.0 (?m)?Rz?18.8 (?m),??i where Rz is a ten-point average roughness (?m) of a charging roller surface, 7 (?m)?d?20 (?m),??ii where d is a thickness (?m) of the surface layer, 9.8 (?m)?D1?15.8 (?m) and 2.8 (?m)?D2?5.2 (?m),??iii where D1 and D2 are average particle size (?m) of the first surface particles, and the second surface particles, respectively, 3.0?D1/D2?5.6, and??iv 0.10?M1/(M1+M2)?0.32,??v where M1 is a total weight (mg) of the first surface particles per unit area of the charging roller surface, and M2 is a total weight (mg) of the second surface particles per unit area of the charging roller surface.

Abstract: A voltage applying portion applies voltage to a current supply member, the current supply member being provided with primary transfer voltage to pass current through a contact portion contacting with a belt, thereby bringing the potential of the belt a primary transfer potential, and being provided with secondary transfer voltage so that a potential difference for secondary transfer is formed between the current supplying member and a support member while a recording material is nipped by the contact portion. The voltage applying portion changes the second transfer voltage so that the potential difference for the secondary transfer between the current supply member and the support member becomes smaller as a potential adjusting portion that maintains the potential of the support member at a prescribed sustaining potential in a variable manner in order to change a primary transfer potential reduces gradually the sustaining potential.

Abstract: An image forming apparatus includes a photoconductor, an exposing unit configured to expose the photoconductor for forming a latent image on the photoconductor based on image data, a developing unit configured to develop, by using toner, the latent image, a transferring unit configured to transfer the image to a sheet, a fixing unit configured to fix toner image transferred onto the sheet, and a control unit configured to divide the image data into a plurality of regions in a sub-scanning direction, determine a target temperature for each region from a result of analyzing the region, and control a temperature of the fixing unit based on the determined target temperature.

Abstract: A developing device includes a casing to contain developer, a developer bearer, an upper and lower developer conveyors to convey the developer to one side in an axial direction of rotation shafts thereof, a communicating portion disposed on a first end side on which an input gear is disposed, to fall the developer from the upper developer conveyor to the lower developer conveyor, bearings to receive end portions the upper and lower developer conveyors, and first and second end seals to seal gaps in the bearings on the upper and lower developer conveyors, respectively. The first end seals and the second end are disposed on the first end side and a second end side, respectively. A sliding friction between the rotation shaft and at least one of the first end seals is smaller than a sliding friction between the rotation shaft and the second end seal.

Abstract: A bearing device includes a first bearing for a first roller; a second bearing for a second roller; a bearing holder for the first and second bearings, wherein when the first bearing is mounted in the holder, a peripheral surface of the first roller is projected out of the holder through an opening of the holder, and the second roller is provided in the second bearing contacting the first roller in the holder; a contact portion for determining a relative position between the first and second bearings by contacting the first bearing with the first bearing mounted in the holder; and a moving mechanism for moving the second bearing toward the opening with dismounting of the first bearing, and for holding the second bearing in a position in which at least a part of a peripheral surface of the second roller projects out of the holder through the opening.

Abstract: An image forming apparatus has a main casing including an opening provided at an upper portion of the main casing, a process cartridge attachable to the main casing through the opening, and a top cover movable between an open position where the top cover opens the opening and a close position where the top cover closes the opening. The process cartridge includes a photosensitive drum and a memory provided with a first electrical contact. The top cover supports an LED head configured to emit light to expose the photosensitive drum, and a second electrical contact electrically connected to the first electrical contact in a state where the process cartridge is attached to the main casing and in a state where the top cover is positioned at the close position.

Abstract: An image forming apparatus includes an image bearing member, a developing device that develops an electrostatic latent image formed on the image bearing member, a toner bottle having a storage portion storing the toner and a discharge portion made of resin and discharging the toner stored in the toner storage portion, and an attachment portion attached with the toner bottle. A driving portion drives the storage portion, a controller controls the driving portion, and a memory disposed in the toner bottle memorizes information regarding component dimensions of a molded discharge portion of the toner bottle. An information reading portion reads information regarding the component dimensions of the molded discharge portion, and the controller controls the driving portion so that a discharge amount of the toner from the discharge portion becomes a specific toner amount targeted based on the information regarding the component dimensions of the molded discharge portion.

Abstract: An endless belt includes a base layer and a resin layer. The base layer includes a metal film. The resin layer is laminated on an outer side of the base layer. The resin layer includes edge portions in an axial direction with at least one edge portion of the edge portions made narrower than the base layer in the axial direction such that the outer side of the base layer is exposed.

Abstract: An image forming apparatus comprises an image forming section; a fixing device; an input section; a storage section which stores a target temperature of the fixing device in a case of carrying out the fixing processing and a target temperature of the fixing device in a case of carrying out the erasing processing; and a control section which controls to read out lower one of the target temperature of the fixation and the target temperature of the erasure from the storage section to set the lower one to the target temperature of the fixing device in a case in which the processing information of the fixing processing and the erasing processing is input by the input section and the processing is continuously carried out, and drive the fixing device via the driving section at a driving speed corresponding to each of the fixing processing and the erasing processing.

Abstract: A fixing device includes a fixing roller, a pressure member, a heating device, a first pressing member, a second pressing member, and a pair of bearings. The pressure member is configured to nip a recording medium in cooperation with the fixing roller. The heating device is disposed opposite to the pressure member relative to the fixing roller. The first pressing member is configured to press the pressure member toward the fixing roller with a first pressing force. The second pressing member is configured to press the heating device toward the fixing roller with a second pressing force. The fixing roller includes a driven gear to be driven by a drive gear that is configured to apply a third pressing force to the driven gear. The third pressing force includes a component opposite in direction to a resultant force of the first pressing force and the second pressing force.

Abstract: An image forming apparatus includes a correcting portion to correct gradation of inputted image data on the basis of a correction condition, an image forming device to form, on a recording material, a toner image corresponding to the corrected image data, a mounting portion, an executing portion to execute an output process for forming and outputting, on the recording material, a predetermined toner image for generating the correction condition, the predetermined toner image including a plurality of image regions different in density, an input portion to permit input of an execution instruction of the output process by an operator, and a controller to control notification of information to the operator. The controller provides notification prompting exchange of the fixing portions in certain cases.

Abstract: A charging member includes a cylindrical or columnar conductive substrate, an elastic layer provided on the conductive substrate, and a surface layer provided on the elastic layer. When in analysis of a circumferential direction period of a surface shape of the elastic layer, a maximum amplitude value in a period region of less than 5 mm is Ae, and when in analysis of a circumferential direction period of a surface shape of the surface layer, a maximum amplitude value in the period region of less than 5 mm is As, the charging member satisfies As/Ae?0.9.

Abstract: A developing device includes a rotatable developer carrying member, first and second chambers configured to accommodate developer supplied to the developer carrying member, and first and second rotatable feeding members provided in the first and second chambers, respectively. A first communication port permits feeding of the developer from the second chamber to the first chamber, and a second communication port permits feeding of the developer from the first chamber to the second chamber. In addition, a toner content detecting portion includes a planar detecting surface including at least a planar coil generating a magnetic field and detects the toner content. The detecting surface is provided in the first communication port above a bottom of the first communication port and is disposed substantially in a central portion of the first communication port.

Abstract: An image forming apparatus forms an image by transferring a toner image to a sheet, the toner image being formed on an image carrier belt with an elastic layer on a surface. The apparatus includes a rigid blade, an angle detector, an angle changer and a hardware processor. The rigid blade contacts with the image carrier from which the toner image has been transferred to the sheet, so as to clean residue attached on the surface of the image carrier. The angle detector detects an effective contact angle between the surface of the image carrier and an opposed surface of the rigid blade opposed to the image carrier. The angle changer changes the effective contact angle. The hardware processor controls the angle changer according to a detection result by the angle detector to regulate the effective contact angle to a predetermined range.

Abstract: An image forming apparatus: acquires, before start of current supply to electric elements including heater, information indicating rated power of the heater and total consumption power of the electric elements excluding the heater; subtracts the total consumption power from upper power limit of the apparatus, and calculates maximum power not exceeding the rated power and remaining power thus subtracted; obtains duty ratio based on assumption of current supply corresponding to the maximum power according to pulse modulation, and determines whether the duty ratio falls within predetermined range; and controls, when the duty ratio falls within the range, drive circuit to supply alternating current by pulse modulation method, and when the duty ratio falls outside the range, to supply the alternating current by phase control method that temporarily interrupts the supply of the alternating current to the heater in half cycles of the alternating current.

Abstract: An image forming apparatus includes a mounting portion for mounting a process cartridge, the process cartridge including a first unit having an image bearing drum, and a second unit having a developing roller, the second unit being movable between a contact position in which the roller contacts the drum and a spaced position in which they are mutually spaced; an engageable member engageable with a force receiving portion provided on the second unit; wherein the engageable member is movable between a first position for maintaining the second unit in the spaced position by engaging with the force receiving portion, a second position for permitting movement of the second unit from the spaced position to the contact position; and a third position for permitting the process cartridge to be mounted, by being pressed by the process cartridge to retract, when the process cartridge is mounted to the mounting portion.

Abstract: A fixing device includes an endless belt, a drive rotator, a driven rotator, a rotation detector, and circuitry. The drive rotator contacts and rotates the endless belt. The driven rotator contacts an inner circumferential surface of the endless belt. The rotation detector detects a rotational speed of the driven rotator. The circuitry is operatively connected to the rotation detector to control a rotational speed of the drive rotator based on the rotational speed of the driven rotator detected by the rotational detector. The circuitry changes the rotational speed of the drive rotator when a recording medium bearing a toner image is not conveyed over the endless belt.

Abstract: A developing device includes a developing roller, a toner supply roller, a casing, a film member, a biasing member, a link member, a link member drive mechanism, and an oscillation mechanism. The film member is disposed on an upper surface of an inner wall portion of the casing, with the biasing member coupled to one longitudinal end of the film member. The link member is coupled to the other longitudinal end of the film member. The link member drive mechanism drives the link member. The link member drive mechanism makes the link member intermittently pull the film member to thereby cause reciprocation of the film member in a longitudinal direction. The oscillation mechanism causes an upper end portion of the film member to oscillate in a direction orthogonal to the upper surface of the inner wall portion along with the reciprocation of the film member.

Abstract: An image forming apparatus includes a housing, a drum, a toner processing module and a first mounting space. The drum is disposed in the housing. The toner processing module supplies toners to the drum. The first mounting space accommodates a first print head. The first print head provides a light ray to perform a writing operation on the drum. When the first print head is present, the light ray of the first print head disposed in the first mounting space passes through an optical channel of the toner processing module to perform the writing operation on the drum. Thus, the optimum configurations of the print head and the drum can be achieved, to effectively reduce a size of the image forming apparatus and satisfy diversified requirements without spending a high cost.

Abstract: A retaining member is integrally formed of an elastically deformable material, and has an inner circumferential portion, an outer circumferential portion, a linkage portion, a plurality of engagement claws, and a slit. The inner and outer circumferential portions are ring-shaped, and the outer circumferential portion is disposed outside the inner circumferential portion in a radial direction. The linkage portion connects the inner circumferential portion and the outer circumferential portion to each other in the radial direction. The engagement claws project from a surface of the inner circumferential portion pointing in a direction of the shaft, and engage with an engagement groove formed in an outer peripheral surface of the shaft. The slit is formed on a side opposite from the linkage portion with a center of the inner circumferential portion located between the slit and the linkage portion, and cuts the inner circumferential portion in the radial direction.