An image forming apparatus includes a charging unit that charges an image bearing member, a developing unit that forms a toner image on an latent image formed on the image bearing member, a transfer unit that transfers the toner image onto a transfer material, a charge neutralizer that neutralizes a charge of the image bearing member downstream of a transfer portion and upstream of a charging portion in a rotating direction of the image bearing member, a conductive collecting unit that collects a material adhering on the image bearing member downstream of the transfer portion and upstream of the charging portion, wherein the developing unit collects residual toner on the image bearing member, an voltage application unit sets a potential difference between the voltage applied to the collecting unit and the surface electric potential of the image bearing member not more than a discharge threshold.

An image forming apparatus includes first and second light sources configured to emit light on a recording material, with the light from the second light source having a peak wavelength that is longer than the peak wavelength of the light from the first light source. The apparatus also includes a light receiving unit configured to receive the first light and the second light transmitted through the recording material. A control unit is configured to control an image forming condition on which the image is formed on the recording material based on the first light and the second light received by the light receiving unit. Additionally, a detection device includes first, second, and third light sources configured to emit first light on a sheet. The detection device further includes a light receiving unit configured to receive the first light and the second light transmitted through the sheet and receive the third light reflected on the sheet.

In a state that a first voltage is applied to a charging member so as to form a surface potential on a region of an image bearing member and a second voltage the same in polarity as the first voltage is applied to a transfer member, a detection unit detects a transfer current in the region of the image bearing member during one rotation of the image hearing member after the region passes through a charging portion, when an absolute value of the surface potential formed on the region immediately before entry into the charging portion is larger than an absolute value of the surface potential formed on the region when it is positioned upstream of a transfer portion and downstream of the charging portion in a rotational direction of the image bearing member.

A photosensitive member unit includes a photosensitive member, a rotary member, a charging roller, a separating member, and a one-way clutch. The charging roller is moved to and positioned at a separated position in a case where the photosensitive member rotates in a second direction when the separating member is positioned at a first position. The charging roller is moved to and positioned at a contact position in a case where the photosensitive member rotates in a first direction when the separating member is positioned at a second position.

A protruding portion protruding in a rotation axis direction of an image bearing member is provided at a position between the tip of a separation claw and an apex of the separation claw, when the apex of the separation claw is disposed at a position farthest from the surface of the image bearing member in a direction perpendicular to a straight line connecting the tip and the rotation center of a shaft portion of the separation claw.

A charging device includes a first charging unit that charges a target unit, which is to be charged, by coming into contact with the target unit and a second charging unit that charges the target unit by coming into contact with the target unit and in which distribution of a contact region in contact with the target unit is different from distribution of a contact region in the first charging unit.

An image forming apparatus includes an image carrier, a toner supply unit, an application roller adjacent to the image carrier, a toner measuring unit, and a control unit. The toner supply unit supplies toner to the image carrier. The application roller applies a lubricant to the image carrier. The toner measuring unit measures an amount of toner transferred from the image carrier to the application roller. The control unit adjusts the supply of toner to be supplied to the image carrier in accordance with the amount of toner measured by the toner measuring unit.

In an image forming apparatus, in a case where a power of the apparatus is turned from OFF to ON, a rotation drive unit rotationally drives each of a developing roller, a first conductive roller, and a second conductive roller in a state where a liquid developer supplied to a developer container by a supply device has reached a supply position, and a bias application unit applies a bias to each of the developing roller, the first conductive roller, and the second conductive roller after the developing roller rotates at least once, in the state where the liquid developer supplied to the developer container by the supply device has reached the supply position.

A process cartridge includes a photosensitive drum, a charge roller unit, and a storage recess. The photosensitive drum is disposed on a body frame. The charge roller unit includes a charge roller and is separate from the body frame. The storage recess stores the charge roller unit. The charge roller unit includes a storage frame and a support. The support supports the charge roller and is movably held on the storage frame. The support includes an operation portion that switches between a remote position and a contact position while the charge roller unit is stored in the storage recess. In the remote position, the charge roller is separated from the photosensitive drum. In the contact position, the charge roller is in contact with the photosensitive drum.

In an image forming apparatus, a bias controller varies one, while keeping the other fixed, of a charging alternating-current frequency, which is the frequency of the charging alternating-current voltage, and a developing alternating-current frequency, which is the frequency of the developing alternating-current voltage. Specifically, in a case where interference fringes appear in a developed image due to interference between the charging and developing alternating-current frequencies, when the recognizable minimum pitch of the interference fringes is A.sub.1 (mm), the width of the variation region of the other frequency is B.sub.1 (Hz), the rotation speed of an image carrying member is C.sub.1 (mm/sec), and the variation speed of the other frequency in the variation region is D.sub.1 (Hz/sec), the bias controller varies the other frequency at a variation speed D.sub.1 that fulfills |D.sub.1|>B.sub.1/(A.sub.1/C.sub.1).