Abstract: An image forming apparatus includes an acquiring portion to acquire information including first information on a rotation amount of a developer carrying member in a first position and second information on the rotation amount of the developer carrying member in a second position, and a controller to control a driving portion for rotating the developer carrying member and the acquiring portion. The controller controls (i) so that both a remaining life of a developing unit is reduced based on the first information and the remaining life of the developing unit is reduced based on the second information, and (ii) so as to change a degree of decrease of the remaining life of the developing unit based on the first information and the degree of decrease of the remaining life of the developing unit based on the second information.

Abstract: An image forming apparatus includes a rotatable image bearing member about a rotational axis extending in the axial direction, a charging member, an accommodating portion accommodating toner charged to a predetermined polarity; a developing member, a transfer portion, a static eliminating portion, and a collecting member. In the axial direction, when A is a eliminating width with which the eliminating portion discharges the surface of the image bearing member, B is an effective charging width with which the charging member charges the surface, and C is a collection contacting width with which the collecting member contacts the surface, the formula A<B<C is satisfied. In the axial direction, a surface potential of the surface in an area outside the effective charging width, inside the collection contacting width and in contact with the collecting member is a first potential larger than 0V in the same polarity direction as the predetermined polarity.

Abstract: An image forming apparatus includes a moving unit to move a developing roller, a driving portion to be capable of rotating the developing roller in either case where the developing roller is located in a contact position in contact with a photosensitive drum or a separated position separated from the photosensitive drum, an acquiring portion to acquire information on a rotation amount of the developing roller and a notifying portion. The acquiring portion corrects a first information, on the rotation amount of the developing roller in the contact position, to a third information by using a first correction coefficient, and corrects a second information, on the rotation amount of the developing roller in the separated position, to a fourth information by using a second correction coefficient. The notifying portion performs the notification on a lifetime of the developing roller based on the third and the fourth information.

Abstract: An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mm2 or more and 3.5 gf/mm2 or less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

Abstract: An image forming apparatus includes an image bearing member, a charging member, an exposure unit, a developing unit including a developer carrying member and a regulating member, a transfer member, a counting portion, a driving portion, and a controller. The controller carries out control so as to perform an image forming operation capable of forming a developer image, on the image bearing member, to be transferred onto a recording material and a non-image forming operation in which the developer image to be transferred onto the recording material is not formed on the image bearing member. Depending on each of count values in a plurality of regions acquired by the counting portion in a predetermined period, the controller controls the driving portion so as to change a rotation amount of the developer carrying member in a developing rotation operation for rotating the developer carrying member during the non-image forming operation.

Abstract: An image forming apparatus includes a rotatable image bearing member about a rotational axis extending in the axial direction, a charging member, an accommodating portion accommodating toner charged to a predetermined polarity; a developing member, a transfer portion, a static eliminating portion, and a collecting member. In the axial direction, when A is a eliminating width with which the eliminating portion discharges the surface of the image bearing member, B is an effective charging width with which the charging member charges the surface, and C is a collection contacting width with which the collecting member contacts the surface, the formula A<B<C is satisfied. In the axial direction, a surface potential of the surface in an area outside the effective charging width, inside the collection contacting width and in contact with the collecting member is a first potential larger than 0V in the same polarity direction as the predetermined polarity.

Abstract: An image forming apparatus includes a rotatable image bearing member about a rotational axis extending in the axial direction, a charging member, an accommodating portion accommodating toner charged to a predetermined polarity; a developing member, a transfer portion, a static eliminating portion, and a collecting member. In the axial direction, when A is a eliminating width with which the eliminating portion discharges the surface of the image bearing member, B is an effective charging width with which the charging member charges the surface, and C is a collection contacting width with which the collecting member contacts the surface, the formula A<B<C is satisfied. In the axial direction, a surface potential of the surface in an area outside the effective charging width, inside the collection contacting width and in contact with the collecting member is a first potential larger than 0V in the same polarity direction as the predetermined polarity.

Abstract: An image forming apparatus includes an image bearing member, a developing member, a transfer unit configured to transfer a toner image, and a brush member configured to come into contact with a surface of the image bearing member in a contact portion. In a case where a ratio of an area in which the brush member is in contact with the image bearing member per unit area in the contact portion is defined as a contact area ratio, and a range in a rotation axis direction of the image bearing member in which the developing member is configured to supply toner to the developing portion is defined as an image area, the brush member includes a portion which is outside the image area in the rotation axis direction and in which the contact area ratio is higher than the contact area ratio in the image area.

Abstract: An image forming apparatus includes a moving unit to move a developing roller, a driving portion to be capable of rotating the developing roller in either case where the developing roller is located in a contact position in contact with a photosensitive drum or a separated position separated from the photosensitive drum, an acquiring portion to acquire information on a rotation amount of the developing roller and a notifying portion. The acquiring portion corrects a first information, on the rotation amount of the developing roller in the contact position, to a third information by using a first correction coefficient, and corrects a second information, on the rotation amount of the developing roller in the separated position, to a fourth information by using a second correction coefficient. The notifying portion performs the notification on a lifetime of the developing roller based on the third and the fourth information.

Abstract: An image forming apparatus includes an image bearing member, a charging member, an exposure unit, a developing unit including a developer carrying member and a regulating member, a transfer member, a counting portion, a driving portion, and a controller. The controller carries out control so as to perform an image forming operation capable of forming a developer image, on the image bearing member, to be transferred onto a recording material and a non-image forming operation in which the developer image to be transferred onto the recording material is not formed on the image bearing member. Depending on each of count values in a plurality of regions acquired by the counting portion in a predetermined period, the controller controls the driving portion so as to change a rotation amount of the developer carrying member in a developing rotation operation for rotating the developer carrying member during the non-image forming operation.

Abstract: An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mm2 or more and 3.5 gf/mm2 or less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

Abstract: An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mm2 or more and 3.5 gf/mm2 or less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

Abstract: An image forming apparatus includes a first image forming portion, a second image forming portion, a belt, a charging voltage applying portion, and a transfer voltage applying portion. With respect to a movement direction of a recording material, the first image forming portion is provided upstream of the second image forming portion. In an image forming operation, a potential difference between a first transfer voltage and a potential at a first transfer portion, which is formed on a first image bearing member and does not form the image, is greater than a potential difference between a second transfer voltage and a potential at a second transfer portion, which is formed on a second image bearing member and does not form an image.

Abstract: An image forming apparatus includes a rotatable image bearing member, a developing member, a transfer member, and a brush contacting a surface of the image bearing member in a contact portion downstream of a transfer portion and upstream of a developing portion with respect to a rotational direction of the image bearing member. The toner which is not transferred onto a toner image receiving member is collected by the developing member. In a charging series, the toner is positioned on the same side as a normal charge polarity of the toner relative to the brush. In the contact portion, a maximum value of a contact pressure of 0.7 gf/mm2 or more and 3.5 gf/mm2 or less, a maximum contact area ratio is 18% or more and 74% or less, and a Clark-Evans index of the brush is 1 or more.

Abstract: An image forming apparatus includes a rotatable image bearing member about a rotational axis extending in the axial direction, a charging member, an accommodating portion accommodating toner charged to a predetermined polarity; a developing member, a transfer portion, a static eliminating portion, and a collecting member. In the axial direction, when A is a eliminating width with which the eliminating portion discharges the surface of the image bearing member, B is an effective charging width with which the charging member charges the surface, and C is a collection contacting width with which the collecting member contacts the surface, the formula A < B < C is satisfied. In the axial direction, a surface potential of the surface in an area outside the effective charging width, inside the collection contacting width and in contact with the collecting member is a first potential larger than 0 V in the same polarity direction as the predetermined polarity.

Abstract: An image forming apparatus includes a first image forming portion, a second image forming portion, a belt, a charging voltage applying portion, and a transfer voltage applying portion. With respect to a movement direction of a recording material, the first image forming portion is provided upstream of the second image forming portion. In an image forming operation, a potential difference between a first transfer voltage and a potential at a first transfer portion, which is formed on a first image bearing member and does not form the image, is greater than a potential difference between a second transfer voltage and a potential at a second transfer portion, which is formed on a second image bearing member and does not form an image.

Abstract: An image forming apparatus includes a first image forming portion, a second image forming portion, a belt, a charging voltage applying portion, and a transfer voltage applying portion. With respect to a movement direction of a recording material, the first image forming portion is provided upstream of the second image forming portion. In an image forming operation, a potential difference between a first transfer voltage and a potential at a first transfer portion, which is formed on a first image bearing member and does not form the image, is greater than a potential difference between a second transfer voltage and a potential at a second transfer portion, which is formed on a second image bearing member and does not form an image.

Abstract: An image forming apparatus includes a latent image forming portion configured to form a latent image on an image bearing member; a developing device including a container configured to store toner and a developing member configured to supply the toner to the latent image formed on the image bearing member to form a toner image; an environment sensor configured to detect environmental information related to an environment in which the developing device is placed; and a controller configured to control switching between a first mode and a second mode, in which a number of prints per unit time is less than that in the first mode. The controller is configured to perform switching from the first mode to the second mode based on an update value obtained by adding or subtracting over time an index value weighted in accordance with the environmental information detected by the environment sensor.

Abstract: An image forming apparatus includes a first image forming portion, a second image forming portion, a belt, a charging voltage applying portion, and a transfer voltage applying portion. With respect to a movement direction of the recording material, the first image forming portion is provided upstream of the second image forming portion. In an image forming operation, a potential difference between the first transfer voltage and a potential, at the first transfer portion, which is formed on the first image bearing member and does not form the image is larger than a potential difference between the second transfer voltage and a potential, at the second transfer portion, which is formed on the second image bearing member and does not form the image.

Abstract: An image forming apparatus includes an image bearing member, a developer container, a developing portion, a replenishment port configured to allow replenishment of one-component developer from a replenishment container, a conveyance portion configured to convey the developer accepted for replenishment through the replenishment port toward the developing portion, a developer remainder amount detection portion whose output value changes on a basis of an amount of developer accommodated in the developer container. A controller changes a developer conveyance speed of the conveyance portion in a conveyance operation on a basis of the output value of the developer remainder amount detection portion, the conveyance operation being an operation of conveying developer toward the developing portion by the conveyance portion and is performed before the image forming operation is started.