Abstract: A snap ring is set to a set portion of a shaft of a rotator from a direction orthogonal to an axial direction of the shaft. The snap ring includes a first arcuate portion and a second arcuate portion facing each other, being elastically deformable in directions away from each other, holding the set portion by elastic deformation restoring force. One ends of the first and second arcuate portions are away from each other to form an insertion portion to insert the set portion. When the snap ring is not used, the first arcuate portion has a same radius of curvature as the second arcuate portion and the set portion, and a center of curvature closer to the second arcuate portion than the first arcuate portion, and the second arcuate portion has a center of curvature closer to the first arcuate portion than the second arcuate portion.

Abstract: A snap ring is set to a set portion of a shaft of a rotator from a direction orthogonal to an axial direction of the shaft. The snap ring includes a first arcuate portion and a second arcuate portion facing each other, being elastically deformable in directions away from each other, holding the set portion by elastic deformation restoring force. One ends of the first and second arcuate portions are away from each other to form an insertion portion to insert the set portion. When the snap ring is not used, the first arcuate portion has a same radius of curvature as the second arcuate portion and the set portion, and a center of curvature closer to the second arcuate portion than the first arcuate portion, and the second arcuate portion has a center of curvature closer to the first arcuate portion than the second arcuate portion.

Abstract: A cam drive device includes a cam to rotate; a displacement body to be displaced in response to a change in a rotation position of the cam in contact with the displacement body; a motor to rotate the cam; and a power source to output an electric current to be supplied to the motor. An electric current to cause a stall torque to the motor being a stop state is changed in response to a change in a rotation stop position of the cam.

Abstract: An image forming apparatus includes an apparatus body, a plurality of image bearers, an endless belt, a contact and separation mechanism to generate a first trajectory and a second trajectory of the endless belt, a sensor to detect an object on a surface of the endless belt, and a positioning mechanism to enable the sensor to detect the object in the first trajectory and the second trajectory of the endless belt. The positioning mechanism includes a stay to support the sensor, a first bracket, a second bracket, a first positioning portion attached to the apparatus body to position the sensor in a direction of rotation of the first bracket and the second bracket at a time of the first trajectory, and a second positioning portion attached to the second bracket to position the sensor in the direction of rotation of the first bracket at a time of the second trajectory.

Abstract: An image forming apparatus includes an apparatus body, a plurality of image bearers, an endless belt, a contact and separation mechanism to generate a first trajectory and a second trajectory of the endless belt, a sensor to detect an object on a surface of the endless belt, and a positioning mechanism to enable the sensor to detect the object in the first trajectory and the second trajectory of the endless belt. The positioning mechanism includes a stay to support the sensor, a first bracket, a second bracket, a first positioning portion attached to the apparatus body to position the sensor in a direction of rotation of the first bracket and the second bracket at a time of the first trajectory, and a second positioning portion attached to the second bracket to position the sensor in the direction of rotation of the first bracket at a time of the second trajectory.

Abstract: A cam drive device includes a cam to rotate; a displacement body to be displaced in response to a change in a rotation position of the cam in contact with the displacement body; a motor to rotate the cam; and a power source to output an electric current to be supplied to the motor. An electric current to cause a stall torque to the motor being a stop state is changed in response to a change in a rotation stop position of the cam.

Abstract: An image forming apparatus includes an image bearer to bear a toner image, a lubricant supply roller to supply lubricant to a surface of the image bearer, a rotation speed changer to change a rotation speed of the lubricant supply roller, and a controller to control the rotation speed changer to change the rotation speed of the lubricant supply roller to a target speed based on a predetermined condition. The controller is configured to control the rotation speed changer to avoid a predetermined speed range.

Abstract: An image forming apparatus includes a process cartridge that includes an image bearer including a rotary shaft and rotates about the rotary shaft; a charger to charge a surface of the image bearer; and a developing device to develop an electrostatic latent image formed on the image bearer into a visible toner image. The charger includes a charging roller that rotates about a shaft together with the image bearer during image formation and electrically charges a surface of the image bearer. A surface linear speed of the charging roller is made slower than a surface linear speed of the image bearer. The image forming apparatus includes a charging roller controller that switches the rotational speed of the charging roller to a first rotational speed slower than the linear speed of the image bearer and a second rotational speed identical to the linear speed of the image bearer.

Abstract: A lubricant applicator includes a lubricant, a supply member contactable against the lubricant to supply the lubricant to a target, and a lubricant gauge to detect whether an amount of lubricant remaining is less than a threshold value. The lubricant gauge includes a rotary member rotatable about a shaft, a pressing member to press and rotate the rotary member as the lubricant is consumed, a contact part of the rotary member pressed by the pressing member, and a detection part of the rotary member opposite to the contact part across the shaft of the rotary member.

Abstract: An image forming apparatus includes an image bearer to bear a toner image, a lubricant supply roller to supply lubricant to a surface of the image bearer, a rotation speed changer to change a rotation speed of the lubricant supply roller, and a controller to control the rotation speed changer to change the rotation speed of the lubricant supply roller to a target speed based on a predetermined condition. The controller is configured to control the rotation speed changer to avoid a predetermined speed range.

Abstract: A lubricant supplying device used with a solid lubricant, includes a supplying member to supply lubricant taken from the solid lubricant to an object to be supplied with the lubricant, and a remaining amount detecting section to detect a remaining amount of the solid lubricant becoming below a predetermined value. A detection of the remaining amount of the solid lubricant is executed when an operation to supply the lubricant to the object to be supplied with the lubricant stops.

Abstract: An image forming apparatus includes a process cartridge that includes an image bearer including a rotary shaft and rotates about the rotary shaft; a charger to charge a surface of the image bearer; and a developing device to develop an electrostatic latent image formed on the image bearer into a visible toner image. The charger includes a charging roller that rotates about a shaft together with the image bearer during image formation and electrically charges a surface of the image bearer. A surface linear speed of the charging roller is made slower than a surface linear speed of the image bearer. The image forming apparatus includes a charging roller controller that switches the rotational speed of the charging roller to a first rotational speed slower than the linear speed of the image bearer and a second rotational speed identical to the linear speed of the image bearer.

Abstract: A process cartridge removably installable in an image forming apparatus includes a cartridge body including an image bearer; a cleaning unit removably attached to the cartridge body and including a lubricant supply device to lubricate the image bearer; a first contact terminal disposed in one of the cleaning unit and the cartridge body; and a second contact terminal disposed in the other of the cleaning unit and the cartridge body. The second contact terminal is disposed to contact the first contact terminal to establish electrical continuity between the cartridge body and the cleaning unit, and an end of the first contact terminal includes a sliding contact portion to slidingly contact the second contact terminal in attachment and removal of the cleaning unit to and from the cartridge body.

Abstract: A lubricant supplying device includes a lubricant supplier contacting an image bearer, a solid lubricant contacting the roller, a detector detecting a lubricant amount, and a controller controlling a supplying of the roller based on a detector detection. The detector outputs to the controller a first signal of a near-end state when the amount reaches a first amount, a second signal of an end state when the amount reaches a second amount smaller than the first amount, and a third signal of an absolute end state when the amount reaches a third amount smaller than the second amount. The controller temporarily stops the supplying when the second signal is output, cancels a roller temporary stopped state even when lubricant replacement is not completed after this state, stops the supplying when the third signal is output, and maintains a roller stopped state until the replacement is completed after this state.

Abstract: An image forming apparatus includes a controller and multiple image forming units each of which includes an image bearer, a toner image forming device to form a toner image on the image bearer, a transfer device to transfer the toner image from the image bearer onto a transfer medium, a cleaning device to remove toner from a surface of the image bearer, a waste-toner tube through which toner removed by the cleaning device is transported, and a toner conveying member to transport toner by rotation and disposed inside the waste-toner tube. The controller changes a rotation speed of the toner conveying member for each of the multiple image forming units according to toner type including a first toner and a second toner having poorer flow properties than the first toner, and at least one image forming units uses the second toner and the rest use the first toner.

Abstract: A lubricant supplying device includes a lubricant supplier contacting an image bearer, a solid lubricant contacting the roller, a detector detecting a lubricant amount, and a controller controlling a supplying of the roller based on a detector detection. The detector outputs to the controller a first signal of a near-end state when the amount reaches a first amount, a second signal of an end state when the amount reaches a second amount smaller than the first amount, and a third signal of an absolute end state when the amount reaches a third amount smaller than the second amount. The controller temporarily stops the supplying when the second signal is output, cancels a roller temporary stopped state even when lubricant replacement is not completed after this state, stops the supplying when the third signal is output, and maintains a roller stopped state until the replacement is completed after this state.

Abstract: A process cartridge removably installable in an image forming apparatus includes a cartridge body including an image bearer; a cleaning unit removably attached to the cartridge body and including a lubricant supply device to lubricate the image bearer; a first contact terminal disposed in one of the cleaning unit and the cartridge body; and a second contact terminal disposed in the other of the cleaning unit and the cartridge body. The second contact terminal is disposed to contact the first contact terminal to establish electrical continuity between the cartridge body and the cleaning unit, and an end of the first contact terminal includes a sliding contact portion to slidingly contact the second contact terminal in attachment and removal of the cleaning unit to and from the cartridge body.

Abstract: A lubricant supplying device used with a solid lubricant, includes a supplying member to supply lubricant taken from the solid lubricant to an object to be supplied with the lubricant, and a remaining amount detecting section to detect a remaining amount of the solid lubricant becoming below a predetermined value. A detection of the remaining amount of the solid lubricant is executed when an operation to supply the lubricant to the object to be supplied with the lubricant stops.

Abstract: A lubricant applicator includes a lubricant, a supply member contactable against the lubricant to supply the lubricant to a target, and a lubricant gauge to detect whether an amount of lubricant remaining is less than a threshold value. The lubricant gauge includes a rotary member rotatable about a shaft, a pressing member to press and rotate the rotary member as the lubricant is consumed, a contact part of the rotary member pressed by the pressing member, and a detection part of the rotary member opposite to the contact part across the shaft of the rotary member.

Abstract: An image forming apparatus including multiple image forming units; a waste-toner container; and a waste-toner conveyance device including a common conveyance channel member disposed in an arrangement direction of the image forming units and provided with toner inlets to receive the waste toner from toner outlets of the cleaning units, communicating channel members identical in structure and respectively disposed between the toner outlets and the toner inlets of the common conveyance channel member, and a rotatable conveying member to transport the waste toner inside the common conveyance channel member linearly along a rotation axis thereof. The common conveyance channel member is shaped to equalize relative positions of each of the toner outlets and a corresponding one of the toner inlets of the common conveyance channel member among the multiple image forming units among which a distance from the toner outlet to the rotation axis differs.