Provided is a cleaning member, comprising an elastic member that includes polyurethane, wherein: when tan ? of a test piece sampled from the elastic member is measured in the temperature range of ?20? C. to +60? C., the peak temperature of a peak indicating the maximum value of tan ? is at 15.0? C. or below; the maximum value of tan ? is 0.20 to 0.55; tan ? at a temperature of 55? C. is 0.13 or larger; and where the detected quantity of all ions obtained when the test piece is heated at a rate of temperature increase of 10? C./second to 1000? C. using a direct-sampling mass spectrometer is M1 and the integrated intensity of a peak in a derived ion thermogram that corresponds to a range of m/z values originating in multifunctional isocyanate with at least three isocyanate groups is M2, M2/M1 is at least 0.001.

A cleaning device scrapes off and removes toner that has adhered to a surface of a rotating photoreceptor, and includes: a cleaning member formed of an elastic body; a leaf spring member for pressing the cleaning member against the surface of the photoreceptor; and a support portion supporting the leaf spring member. The cleaning member is fixed to one end of the leaf spring member, and the other end of the leaf spring member is fixed to the support portion with a cushioning member formed of an elastic body interposed therebetween. The cushioning member is fixed to the other end of the leaf spring member by an adhesive.

A cleaning unit includes a case, a blade, a swing member, a first coil spring, a second coil spring, and a plurality of first engaging portions. The first coil spring is provided on a first end side of the blade in the longitudinal direction and configured to pull the swinging member. The second coil spring is provided on a second end side of the blade in the longitudinal direction and configured to pull the swinging member. The plurality of first engaging portions are provided on one of the case or the swinging member at the first end side of the blade and configured to selectively engage a one end side of the first coil spring at different positions with respect to the longitudinal direction of the blade so that a contact pressure of the blade against the image bearing member caused by the first coil spring is changed.

A process unit includes a photosensitive drum on which an electrostatic latent image is to be formed, a charger that charges an outer circumferential surface of the photosensitive drum to a predetermined polarity and a predetermined potential, a cleaner that removes residual toner from the outer circumferential surface of the photosensitive drum, a process frame that holds the photosensitive drum and is provided with the cleaner, and a charger cover that holds the charger and is rotatably supported on the process frame so as to move the charger away from or closer to the photosensitive drum.

A developing apparatus includes a developer carrying member, a developer container, and a regulating member to regulate the thickness of the developer. The regulating member includes a support member having one end fixed to the developer container and the other end free, with the support member extending in a direction opposite to the rotating direction of the developer carrying member, and a contact member to be fixed to the other end of the support member and to contact the developer carrying member. The contact member includes a contact curved surface along a peripheral surface of the developer carrying member, and an opposite surface to face the developer carrying member. The contact pressure of the contact curved surface applied to the developer carrying member decreases as a location on the developer carrying member approaches a downstream side in the rotating direction.

A support member that supports an elastic member constituted of an elastic body contacting the surface of an image bearing member has a first surface that extends in a rotation axis direction of the image bearing member, and a second surface that includes a normal vector, which intersects with a normal vector of the first surface, and extends in the rotation axis direction. In the rotation axis direction, the first surface is fixed to two fixed portions of the frame, and a first vibration absorbing member is disposed between the two fixed portions so as to contact the frame and the first surface.

An intermediate transfer unit includes an endless intermediate transfer belt to which a toner image is primarily transferred from an image carrying member, a driving roller that conveys the intermediate transfer belt with the primarily transferred toner image to a secondary transfer position for a sheet material, and a cleaning device which cleans a peripheral surface of the driving roller around which the intermediate transfer belt is wound.

At the time of an end of an image forming job (YES of S1), a controller causes a blade and a developing roller to be separated from a photosensitive drum (S2). At that time, the controller controls separation timing of the belt and the developing roller so that the developing roller is separated from the photosensitive drum before a surface position of the photosensitive drum contacted to the developing roller at a contact position at the time of a start of separation of the blade from the photosensitive drum reaches a developing position with the separation of the blade. According to this, even when a liquid accumulation reaches the developing position depending on the separation of the blade, the developing roller has already been separated from the photosensitive drum before the liquid accumulation reaches the developing position and therefore, the liquid accumulation is not collected by the developing roller. When the liquid accumulation is not collected by the developing roller, color mixture due to the liquid accumulation does not occur.

The present disclosure provides a process cartridge and a potential detection part. The process cartridge includes a cartridge body, a photosensitive drum rotatably installed at the cartridge body, and a potential detection part configured to detect an electrical signal on the image-forming region. The potential detection part includes a detection starting portion and a detection ending portion; the detection starting portion and the detection ending portion respectively correspond to a detection starting position and a detection ending position of a detectable region of the potential detection part along a first direction; a maximum distance along the first direction between orthographic projections of the detection starting portion and the detection ending portion on the image-forming region is L1; a length of the image-forming region along the first direction is L2; the first direction is in parallel with an axis direction of the photosensitive drum; and L1/L2>?.

An image forming apparatus which transfers, onto paper, a toner image formed on a belt-shaped image carrier including an elastic layer on a surface thereof, and forms an image includes a rigid blade which cleans the surface of the image carrier in contact with the image carrier which has transferred the toner image onto the paper; a roller which is upstream of the rigid blade in a rotation direction of the image carrier, and cleans the surface of the image carrier upstream of the rigid blade by coming in contact with the image carrier which has transferred the toner image onto the paper; a rigid blade holder which holds the rigid blade; and a roller holder which holds the roller. The rigid blade holder and the roller holder are installed with a gap therebetween.