An optical scanning device includes a housing having light emitting ports extending in a predetermined direction, a transparent cover that closes the light emitting ports, a screw shaft arranged so as to extend in the predetermined direction along the transparent cover, a holding member having an engaging part engaged with the screw shaft, and a cleaning member held to the holing member. An abutting fulcrum is provided at an end of a movement path of the holing member, abuts a predetermined place of a surface of a front side in a progress direction of the holing member, allows the holing member to rotate by employing an abutting part of the holding member with the abutting fulcrum as a fulcrum, and reduces a position shift amount between the one side end portion and the other side end portion of the holing member in the progress direction.

A foreign substance collection apparatus includes: a frame body; a photosensitive drum; a cleaning roller which collects foreign substances from a surface of the photosensitive drum; a collecting roller which further collects the foreign substances having been collected by the cleaning roller from the cleaning roller; and a scraping member which scrapes off the foreign substances from the collecting roller. A foreign substance collecting portion included in the frame body has, in a posture during use: a first inner bottom surface which is positioned below the scraping member in a gravity direction; an outer bottom surface which is positioned further below the first inner bottom surface; and a connecting surface which intersects the first inner bottom surface and the outer bottom surface and which connects the first inner bottom surface and the outer bottom surface with each other.

A photosensitive drum rotates about a first axis extending in a first direction. A photosensitive drum is located at one end portion of a housing in a second direction. A cleaning roller cleans a surface of the photosensitive drum. The cleaning roller rotates about a second axis extending in the first direction. A cleaning electrode is electrically connected to the cleaning roller. The cleaning electrode is located at an outer surface of the housing in the first direction. The cleaning electrode is located at a tip end of the one end portion of the housing in the second direction. The cleaning electrode includes a contact surface and a guide surface. The contact surface contacts an electrical contact to which a voltage is supplied. The contact surface is perpendicular to the first direction. The guide surface guides the electrical contact to the contact surface when the drum cartridge is mounted.

An image forming apparatus includes a density sensing portion, a cleaning portion, and a control portion. The density sensing portion includes a substrate and a sensor package and outputs a sensing value related to a toner density of a toner image formed on an outer circumferential surface of an image carrier. The control portion performs control so that, when the cleaning portion performs cleaning of a sensing surface, a brush is moved to a cleaning position where the brush contacts the sensing surface. The control portion also performs control so that, when the cleaning portion does not perform the cleaning of the sensing surface, the brush is moved to a retracted position where the brush does not contact the sensor package and the substrate.

A foreign substance collection apparatus includes: a frame body; a photosensitive drum; a cleaning roller which collects foreign substances from a surface of the photosensitive drum; a collecting roller which further collects the foreign substances having been collected by the cleaning roller from the cleaning roller; and a scraping member which scrapes off the foreign substances from the collecting roller. A foreign substance collecting portion included in the frame body has, in a posture during use: a first inner bottom surface which is positioned below the scraping member in a gravity direction; an outer bottom surface which is positioned further below the first inner bottom surface; and a connecting surface which intersects the first inner bottom surface and the outer bottom surface and which connects the first inner bottom surface and the outer bottom surface with each other.

An image forming apparatus includes a photosensitive drum, an LED unit, and a housing. The LED unit is configured to expose the photosensitive drum. The LED unit has a light emitting surface. The housing includes a discharge portion and a discharge tray. The discharge portion has a discharge opening configured to discharge a sheet. The sheet discharged from the discharge opening is placed on the discharge tray. The discharge tray has a cleaning opening for cleaning the light emitting surface of the LED unit. The LED unit is configured to move between: a first position at which the LED unit exposes the photosensitive drum; and a second position at which the light emitting surface is closer to the cleaning opening than a state where the LED unit is located at the first position.

A photosensitive drum rotates about a first axis extending in a first direction. A photosensitive drum is located at one end portion of a housing in a second direction. A cleaning roller cleans a surface of the photosensitive drum. The cleaning roller rotates about a second axis extending in the first direction. A cleaning electrode is electrically connected to the cleaning roller. The cleaning electrode is located at an outer surface of the housing in the first direction. The cleaning electrode is located at a tip end of the one end portion of the housing in the second direction. The cleaning electrode includes a contact surface and a guide surface. The contact surface contacts an electrical contact to which a voltage is supplied. The contact surface is perpendicular to the first direction. The guide surface guides the electrical contact to the contact surface when the drum cartridge is mounted.

A foreign substance collection apparatus includes: a frame body; a photosensitive drum; a cleaning roller which collects foreign substances from a surface of the photosensitive drum; a collecting roller which further collects the foreign substances having been collected by the cleaning roller from the cleaning roller; and a scraping member which scrapes off the foreign substances from the collecting roller. A foreign substance collecting portion included in the frame body has, in a posture during use: a first inner bottom surface which is positioned below the scraping member in a gravity direction; an outer bottom surface which is positioned further below the first inner bottom surface; and a connecting surface which intersects the first inner bottom surface and the outer bottom surface and which connects the first inner bottom surface and the outer bottom surface with each other.

An image forming apparatus includes a photosensitive drum, an LED unit, and a housing. The LED unit is configured to expose the photosensitive drum. The LED unit has a light emitting surface. The housing includes a discharge portion and a discharge tray. The discharge portion has a discharge opening configured to discharge a sheet. The sheet discharged from the discharge opening is placed on the discharge tray. The discharge tray has a cleaning opening for cleaning the light emitting surface of the LED unit. The LED unit is configured to move between: a first position at which the LED unit exposes the photosensitive drum; and a second position at which the light emitting surface is closer to the cleaning opening than a state where the LED unit is located at the first position.

A foreign substance collection apparatus includes: a frame body; a photosensitive drum; a cleaning roller which collects foreign substances from a surface of the photosensitive drum; a collecting roller which further collects the foreign substances having been collected by the cleaning roller from the cleaning roller; and a scraping member which scrapes off the foreign substances from the collecting roller. A foreign substance collecting portion included in the frame body has, in a posture during use: a first inner bottom surface which is positioned below the scraping member in a gravity direction; an outer bottom surface which is positioned further below the first inner bottom surface; and a connecting surface which intersects the first inner bottom surface and the outer bottom surface and which connects the first inner bottom surface and the outer bottom surface with each other.