An image forming apparatus includes an image bearing member, a belt, a development unit having a development member in contact with the image bearing member to develop an electrostatic latent image formed on the image bearing member using toner, and a collection unit having a contacting member in contact with the belt to collect toner remaining on the belt adjacent to the contacting member. If condensation is detected inside the image forming apparatus, the image forming apparatus performs predetermined control to separate the development member from the image bearing member and drive the belt in such a manner that the belt moves at a second surface speed different from a first surface speed while driving the image bearing member in such a manner that the image bearing member rotates at the first surface speed in a state where the image bearing member is in contact with the belt.

An image forming apparatus includes a heating device including a heater, a developing device, and an airflow generation device. The heater includes a base, a heat generator, an electrode portion, and conductive portions. The conductive portions are disposed on one side and another side in a longitudinal direction in a heat generation region and spaced apart in a lateral direction intersecting the longitudinal direction. A maximum total value among total values of squares of current flowing in the conductive portions at longitudinal positions on the one side is larger than that on said another side. The developing device includes a rotating member and sliding portions. A sliding portion having highest temperature in operation is disposed on one side of the developing device being same as the one side of the heater in the longitudinal direction. The airflow generation device generates an airflow toward the one side of the developing device.

An image forming system includes: an image forming apparatus that includes a transfer device that transfers a toner image onto a sheet and a fixing device that fixes the toner image; a sheet heating device that heats the sheet on an upstream of the fixing device in a sheet conveyance direction; a first detector that detects a temperature inside the image forming apparatus; a second detector that detects a temperature of the sheet before the sheet heating device heats the sheet; and a controller that causes the sheet heating device to heat the sheet based on a detection result by the second detector and a sheet passing condition of the sheet, and corrects at least one of a transfer current and a transfer voltage in the transfer device based on a detection result by the first detector in a case where the sheet heating device heats the sheet.

An image forming apparatus includes an image forming portion, a transfer belt, a secondary transfer portion, a cleaning member contacting a surface of the transfer belt for cleaning the surface of the transfer belt, a fixing device, an exhausting device, a duct portion and a sheet member. The sheet member is provided on the exhausting device so as to project toward the transfer belt from the exhausting device, the sheet member being opposed to transfer belt and separated by a predetermined space downstream of the transfer portion and upstream of the cleaning member with respect to a rotational direction of the transfer belt, and being configured to prevent air flow between the exhausting device and the transfer belt from flowing downstream with respect to the rotational direction.

A fan introduces air and send the air toward an air blow target. The fan includes an impeller and a casing. The casing includes a first wall covering the impeller, a second wall covering the impeller and facing the first wall, and a peripheral wall surrounding the impeller and connecting the first and second walls. The peripheral wall has an air discharge port for discharging air toward the air blow target. The impeller is located between the first wall and the second wall. The second wall is located closer to a side cover than the first wall is. At least the first wall or the second wall has an air inlet port for introducing air into the casing. The outside air inlet is located at a different position from the air inlet port as viewed from a facing direction in which the fan and the side cover face each other.

An image forming apparatus includes: a body of the image forming apparatus; a first inclined portion that is inclined upward from one side surface toward another side surface of the body of the image forming apparatus; a second inclined portion that is inclined downward from an inner end portion of the first inclined portion toward the one side surface; multiple cooled parts that are disposed in a space between the first inclined portion and the second inclined portion and that are disposed to be spaced from each other in a direction from the one side surface to the other side surface; a first wall member that is disposed above the first inclined portion and that has a first ventilation part; and a second wall member that is disposed below the second inclined portion and that has a second ventilation part.

An image forming apparatus includes: a body of the image forming apparatus; a first inclined portion that is inclined upward from one side surface toward another side surface of the body of the image forming apparatus; a second inclined portion that is inclined downward from an inner end portion of the first inclined portion toward the one side surface; multiple cooled parts that are disposed in a space between the first inclined portion and the second inclined portion and that are disposed to be spaced from each other in a direction from the one side surface to the other side surface; a first wall member that is disposed above the first inclined portion and that has a first ventilation part; and a second wall member that is disposed below the second inclined portion and that has a second ventilation part.

A channel switching device includes: an accommodation portion in which a unit is detachably accommodated; a first channel; a second channel passing through the accommodation portion; and a switch separating the first channel and the second channel, the switch including: a first communication portion communicating with the first channel and the second channel; and a second communication portion disposed at a different position with the first communication portion, the second communication portion communicating with the first channel and the second channel, and the switch configured to switch to one of the first communication portion or the second communication portion in response to an attachment or detachment of the unit to the accommodation portion.

A channel switching device includes: an accommodation portion in which a unit is detachably accommodated; a first channel; a second channel passing through the accommodation portion; and a switch separating the first channel and the second channel, the switch including: a first communication portion communicating with the first channel and the second channel; and a second communication portion disposed at a different position with the first communication portion, the second communication portion communicating with the first channel and the second channel, and the switch configured to switch to one of the first communication portion or the second communication portion in response to an attachment or detachment of the unit to the accommodation portion.

An exhaust device includes: a flow path section through which gas containing ozone generated inside a device body flows; a joint section connected to the flow path section with an inlet opening where hot gas generated inside the device body flows, and where gas containing ozone and hot gas are joined internally; a first air flow generator that generates an air flow which causes the gas containing ozone to flow through the flow path section and to the joint section; and a second air flow generator that causes the gas containing ozone and the hot gas to be joined and discharged from the joint section to outside the device body so that a flow rate of the joint gas discharged from the joint section to outside the device body is higher than a flow rate of the gas containing ozone to the joint section by the first air flow generator.