A control circuit of an image forming apparatus outputs a pulse signal. A clock signal generation circuit generates a clock signal, based on the pulse signal. A pulse signal conversion circuit generates a pulse conversion control signal of a voltage value associated with a duty ratio of the pulse signal. An AC voltage generation circuit generates an AC voltage of a frequency based on the clock signal. Either the AC voltage generation circuit or a DC voltage generation circuit generates a voltage whose amplitude or voltage value increases as a voltage value of the received pulse conversion control signal increases, and whose amplitude or voltage value decreases as a voltage value of the pulse conversion control signal decreases.

An image forming apparatus of the present invention includes: a body; a developing cartridge having a memory medium and a developer bearing member; a tray including a frame which is movable between a housed position and a drawn-out position and has side portions extending in the moving direction and to which the developing cartridge is attachable, an image bearing member that faces the developer bearing member when the developing cartridge is attached, a tray-side metal terminal provided on the side portion and electrically connected to the memory medium when the cartridge is attached, and a tray guide portion extending along the moving direction; a body-side metal terminal that faces the tray-side metal terminal when the tray is housed, wherein the tray-side metal terminal is provided below the tray guide portion.

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.

An image forming apparatus includes a rotatable photosensitive member, a charging member, an exposure unit, a developing member, a transfer member, and a pre-exposure unit. The pre-exposure unit exposes a surface of the photosensitive member after the toner image is transferred to the recording material and before being charged by the charging member. The pre-exposure unit includes a substrate disposed adjacent to one end of the photosensitive member with respect to a longitudinal direction of the photosensitive member, and in which a first light emitting element and a second light emitting element having directional characteristics narrower than that of the first light emitting element are mounted.

An image forming apparatus includes a rotatable image bearing member, a charging member, a developing member, a transfer member, an exposure unit, and a controller. The controller executes a preparatory operation in which before an image forming operation, rotation of the image bearing member is started and a charging voltage and a developing voltage are increased stepwise. In the preparatory operation, the controller carries out control so as to start application of the charging voltage at a voltage value not less than a discharge start voltage of the charging member before a surface region of the image bearing member positioned in a developing portion at a time of a start of the rotation of the image bearing member reaches a charging portion in a state which a surface of the image bearing member is exposed to light by the exposure unit.

An image forming apparatus includes an image forming unit configured to form an image on a rotating photosensitive member to transfer the image on a recording medium, and a controller configured to control the image forming unit to form a test image and a scale correlated with a phase of the photosensitive member on a recording medium, acquire information related to a determination result, which is determined by a user based on the scale, of correspondence relationship between an uneven density of the test image and the phase of the photosensitive member, and control an uneven density in a rotating direction of the photosensitive member which occurs in the image formed by the image forming unit based on the information.

An image forming apparatus includes an image bearing member, a developer bearing member, a driving unit, a latent image forming unit that forms an electrostatic image having light area potential and a dark area potential, and an application unit that applies a developing bias. The driving unit drives the image bearing member and the developer bearing member in a first peripheral speed ratio and a second peripheral speed ratio larger than the first peripheral speed ratio. The image forming apparatus further includes an acquiring unit acquiring information related to a change in an electrostatic capacitance of the image bearing member and a determining unit determining a developing contrast according to the electrostatic capacitance. The determining unit determines the developing contrast based on the acquired information when the driving unit drives the image bearing member and the developer bearing member in the second peripheral speed ratio.

An image forming apparatus includes a photoconductor, a charger, a detection unit, and a determination unit. The charger charges the photoconductor. The detection unit detects an actual charging potential of the photoconductor after the photoconductor is charged by the charger. The determination unit determines one of a plurality of causes related to a charging abnormality of the photoconductor based on a relationship between a standard charging potential of the photoconductor to be obtained by charging by the charger and a charging potential detected by the detection unit.

An image forming apparatus includes a rotatable photosensitive member, a charging member, a developing device, a blade, a detecting portion, and a controller. The controller causes the photosensitive member to rotate through one full circumference or more on the following conditions during a predetermined operation: (i) a voltage which is a discharge start voltage or more is applied to the charging member, and (ii) an operation condition of the developing device is a first condition on which an amount of fog toner deposited from the developer carrying member on the photosensitive member is smaller than an amount of the fog toner on a second condition which is an operation condition of the developing device during a sheet interval before the image formation during the continuous image formation is interrupted.

An image forming apparatus includes an image forming unit configured to form an image on a recording material, a printed circuit board including a voltage generation unit mounted thereon and configured to generate a voltage to be applied to the image forming unit, a conductive member provided on the printed circuit board, to which the voltage generated by the voltage generation unit is applied, an elastic member including an arm portion configured to be biased toward the conductive member, and configured to connect the conductive member and the image forming unit, and a holding unit configured to hold the arm portion of the elastic member at a position where the arm portion is not in contact with the conductive member.