An image forming apparatus includes: a capacitance detector that detects capacitance of an opposing member disposed opposite to a photoconductor, wherein the capacitance detector detects the capacitance of the opposing member, based on a result of measurement of a current flowing due to potential difference between a voltage applied to the opposing member and the photoconductor being charged.

An image forming apparatus includes an image holding member, a charging unit that charges the surface of the image holding member, an electrostatic latent image forming unit that forms an electrostatic latent image on the charged surface of the image holding member, a developing unit that develops the electrostatic latent image to form a toner image, a transferring unit that transfers the toner image to a first side of a recording medium, a fixing unit that allows the recording medium having the transferred toner image to pass through a nipping region to fix the toner image, a first charging unit that faces the first side of the recording medium and that charges particles, and a second charging unit that charges a second side of the recording medium to the opposite polarity to the charged particles after the recording medium passes through the nipping region.

An image forming apparatus includes an image holding member, a charging unit that charges the surface of the image holding member, an electrostatic latent image forming unit that forms an electrostatic latent image on the charged surface of the image holding member, a developing unit that develops the electrostatic latent image to form a toner image, a transferring unit that transfers the toner image to a first side of a recording medium, a fixing unit that allows the recording medium having the transferred toner image to pass through a nipping region to fix the toner image, a first charging unit that faces the first side of the recording medium and that charges particles, and a second charging unit that charges a second side of the recording medium to the opposite polarity to the charged particles after the recording medium passes through the nipping region.

An image forming apparatus includes an exhaust duct to guide air inside the image forming apparatus to an outside of the image forming apparatus. A positive ion generator emits a positive ion into the exhaust duct. A negative ion generator emits a negative ion into the exhaust duct. The negative ion generator is shifted from the positive ion generator in one of an air flow direction of the air moving inside the exhaust duct and a direction perpendicular to the air flow direction.

An image forming apparatus includes an exhaust duct to guide air inside the image forming apparatus to an outside of the image forming apparatus. A positive ion generator emits a positive ion into the exhaust duct. A negative ion generator emits a negative ion into the exhaust duct. The negative ion generator is shifted from the positive ion generator in one of an air flow direction of the air moving inside the exhaust duct and a direction perpendicular to the air flow direction.