An image forming apparatus includes an image bearing member, a charging member, a developing member, a transfer unit, a pre-charging exposure unit, a voltage receiving member, a measuring portion, and a controller for determining a light quantity of the pre-charging exposure unit during image formation. The controller includes, a light quantity controller for controlling the light quantity so that the image bearing member charged by applying a first potential to the charging member is exposed to light at a first light quantity by the pre-charging exposure unit, and an acquiring portion for acquiring an output of the measuring portion when the image bearing member exposed to light at the first light quantity is charged by applying a second potential of an opposite polarity to a polarity of the first potential to the voltage receiving member.

An image forming apparatus includes a photosensitive drum, a charging roller, a development device, a transfer roller, a first electricity eliminator and a controller. The photosensitive drum is provided on a conveyance path along which a sheet is conveyed. The charging roller charges the photosensitive drum. The development device develops an electrostatic latent image formed on the photosensitive drum charged by the charging roller. The transfer roller faces the photosensitive drum across the conveyance path and generates a transfer bias. The first electricity eliminator irradiates the photosensitive drum with light on a downstream side of the development device in a rotational direction of the photosensitive drum and on an upstream side of the transfer roller in the rotational direction. The controller which controls the first electricity eliminator so as to irradiate only a non-sheet passing area of the photosensitive drum with the light.

An image forming apparatus includes a photosensitive drum, a charging roller, a development device, a transfer roller, a first electricity eliminator and a controller. The photosensitive drum is provided on a conveyance path along which a sheet is conveyed. The charging roller charges the photosensitive drum. The development device develops an electrostatic latent image formed on the photosensitive drum charged by the charging roller. The transfer roller faces the photosensitive drum across the conveyance path and generates a transfer bias. The first electricity eliminator irradiates the photosensitive drum with light on a downstream side of the development device in a rotational direction of the photosensitive drum and on an upstream side of the transfer roller in the rotational direction. The controller which controls the first electricity eliminator so as to irradiate only a non-sheet passing area of the photosensitive drum with the light.

A discharging light quantity adjusting device includes a potential measurement controller that performs: a process of causing a first toner image forming process to charge an image holding member to a first potential and an electrometer to measure an electrostatic potential on the image holding member to obtain a first value, a process of causing a second toner image forming process to charge the image holding member to a second potential and removing a toner image formed by the second toner image forming process, and a process of causing a third toner image forming process to charge the image holding member to a third potential, and causing the electrometer to measure an electrostatic potential on the image holding member to obtain a second value; and a light quantity adjusting unit that adjusts a quantity of a discharging light based on the first and second values.

An image forming apparatus includes: a photoconductor; an electric charging device charging the photoconductor; an exposure device exposing a portion of the photoconductor charged by the electric charging device to light based on image information, to form an electrostatic latent image; a first charge eliminating device emitting light to the photoconductor so as to eliminate an electric charge on a surface of the photoconductor; a second charge eliminating device emitting light to the photoconductor so as to eliminate an electric charge on a surface of the photoconductor, a wavelength of the light emitted by the first charge eliminating device being different from a wavelength of the light emitted by the second charge eliminating device; and a controller selectively operating the first and second charge eliminating devices depending on an image content of the electrostatic latent image in an image forming process.

An image forming apparatus includes: an image holding section that includes a photoconductor having a surface protection layer; a charging section that charges a surface of the image holding section with a direct current potential; an exposure section that exposes the surface of the image holding section charged by the charging section to form an electrostatic latent image; a developing section that develops the electrostatic latent image formed on the image holding section; a transfer section that electrostatically transfers a visible image formed on the image holding section to a transfer medium; an exposure static elimination section that eliminates a residual charge of the image holding section by using the exposure section when image formation on the image holding section is stopped; a transfer static elimination section that eliminates the residual charge of the image holding section by using at least the transfer section when the image formation on the image holding section is stopped; and a switching section that causes the exposure static elimination section to perform static elimination under a condition that the residual charge of the image holding section does not exceed a threshold value of an allowable static elimination level at which the residual charge is eliminated by the exposure static elimination section, and causes the transfer static elimination section instead of the exposure static elimination section to perform static elimination under a condition that the residual charge exceeds the threshold value.

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 an image bearing member, a charging member to charge a surface of the image bearing member, an exposure unit, a developing member to form a toner image, a transfer member, an irradiation unit, and a blocking member. The irradiation unit includes a light source provided at one end of the irradiation unit in a rotation axial direction of the image bearing member and a guide that guides a light source emitted light in the rotation axial direction. The irradiation unit irradiates the surface of the image bearing member with the light after the transfer member transfers the toner image to a transfer-receiving member. The blocking member blocks the light irradiated from the irradiation unit in the rotation axial direction. The blocking member is configured so that a quantity of blocking the light irradiated from the irradiation unit is different in the rotation axial direction.

An image forming apparatus includes an image bearing member, a charging member to charge a surface of the image bearing member, an exposure unit, a developing member to form a toner image, a transfer member, an irradiation unit, and a blocking member. The irradiation unit includes a light source provided at one end of the irradiation unit in a rotation axial direction of the image bearing member and a guide that guides a light source emitted light in the rotation axial direction. The irradiation unit irradiates the surface of the image bearing member with the light after the transfer member transfers the toner image to a transfer-receiving member. The blocking member blocks the light irradiated from the irradiation unit in the rotation axial direction. The blocking member is configured so that a quantity of blocking the light irradiated from the irradiation unit is different in the rotation axial direction.

An image forming apparatus includes a transfer belt and a plurality of image forming units. The image forming unit includes a photosensitive drum and a charge elimination part. The charge elimination part of a predetermined image forming unit irradiates a downstream area of the primary transfer position on the photosensitive drum of the predetermined image forming unit with post-transfer charge elimination light and irradiates an upstream area of a primary transfer position on the photosensitive drum of the other image forming unit disposed on a downstream side of the predetermined image forming unit in the conveyance direction. A slit part is provided between the predetermined image forming unit and the other image forming unit for narrowing an irradiation width of the pre-transfer charge elimination light in a circumferential direction of the photosensitive drum.