A toner detection device includes sensor cases, optical sensors, a cleaning member, a motor, and a control unit. The sensor cases include detection surfaces and are placed on wall surfaces of a hopper container. The optical sensors are housed in the sensor cases and detect presence or absence of toner at a specified elevation through the detection surfaces. The cleaning member slides and rubs on the detection surfaces. The motor moves the cleaning member. In case where the cleaning member is to be stopped, the control unit controls the motor so as to stop the cleaning member in a region in which the cleaning member does not come into contact with the detection surfaces.

A powder detection device includes a detection unit, a cleaning unit, and a drive unit. The detection unit includes detection surfaces provided in a storage container and enables detection of powder through the detection surfaces. The cleaning unit removes the powder from the detection surfaces by sliding along the detection surfaces. The drive unit reciprocates the cleaning unit along a path extending through the detection surfaces and differentiates a speed at which the cleaning unit is moved in a first direction along the path from a speed at which the cleaning unit is moved in a second direction opposite to the first direction.

An image forming apparatus includes an apparatus body, an image bearing member, and a process unit attached to the apparatus body, the process unit including a frame including a storage portion configured to store developer, a developer bearing member configured to supply developer to the image bearing member to develop an electrostatic latent image; and a circuit board attached to the frame, wherein the circuit board includes a light emitting portion configured to emit light, and a light receiving portion configured to receive the light emitted from the light emitting portion and having passed through an interior of the storage portion.

A toner conveying apparatus includes a frame body, a conveyance member, a light transmission portion, a light emission portion, a light reception portion, and a rubbing member. The frame body forms a conveyance passage surrounded by a wall portion and is provided with a reception inlet for receiving toner from outside. The conveyance member is provided in the conveyance passage and rotates around a first rotation axis to convey the toner. The light transmission portion that is provided in the wall portion and has translucency. The light emission portion emits light toward an inside of the conveyance passage through the light transmission portion. The light reception portion receives the light emitted from the light emission portion through the light transmission portion. The rubbing member rubs on the light transmission portion by being rotated around a second rotation axis extending in a direction crossing the first rotation axis.

A toner level detector, includes: a toner cartridge storing toner and having one side provided with a light-permeable region; an agitator, which is rotatably disposed in the toner cartridge and agitates the toner; a reflective region disposed on an inner surface on the other side of the toner cartridge; a first cleaner disposed on one side of the agitator; a second cleaner disposed on the other side of the agitator; and a transceiver, which is disposed on a body outside the toner cartridge, and outputs an emitting signal to the reflective region through the light-permeable region, wherein the reflective region reflects the emitting signal to generate a reflective signal received by the transceiver through the reflective region, wherein the first cleaner, which is rotating, intermittently cleans the light-permeable region, which is fixed; and the second cleaner, which is rotating, intermittently cleans the reflective region, which is fixed.

A toner conveying apparatus includes a frame body, a conveyance member, a light transmission portion, a light emission portion, a light reception portion, and a rubbing member. The frame body forms a conveyance passage surrounded by a wall portion and is provided with a reception inlet for receiving toner from outside. The conveyance member is provided in the conveyance passage and rotates around a first rotation axis to convey the toner. The light transmission portion that is provided in the wall portion and has translucency. The light emission portion emits light toward an inside of the conveyance passage through the light transmission portion. The light reception portion receives the light emitted from the light emission portion through the light transmission portion. The rubbing member rubs on the light transmission portion by being rotated around a second rotation axis extending in a direction crossing the first rotation axis.

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.

An image forming apparatus includes a toner container, a first conveyance unit, and an apparatus main body. The apparatus main body includes a photosensitive drum, a development roller, a second conveyance unit, a toner conveyance passage, light sensor, an acquisition unit, and a control unit configured to execute an abnormality detection mode. In an abnormality detection mode, the acquisition unit acquires a first acquired value after the driving of the second conveyance unit with the driving of the first conveyance unit stopped. When the first acquired value satisfies a first condition, the acquisition unit further acquires a second acquired value after the driving of the second conveyance unit with the driving of the first conveyance unit stopped. The apparatus main body further includes a notification unit to make notification of the abnormality when the second acquired value satisfies a second condition.

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 toner detection device includes sensor cases, optical sensors, a cleaning member, a motor, and a control unit. The sensor cases include detection surfaces and are placed on wall surfaces of a hopper container. The optical sensors are housed in the sensor cases and detect presence or absence of toner at a specified elevation through the detection surfaces. The cleaning member slides and rubs on the detection surfaces. The motor moves the cleaning member. In case where the cleaning member is to be stopped, the control unit controls the motor so as to stop the cleaning member in a region in which the cleaning member does not come into contact with the detection surfaces.