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.

An image forming apparatus includes an image carrier, a toner supply unit, an application roller adjacent to the image carrier, a toner measuring unit, and a control unit. The toner supply unit supplies toner to the image carrier. The application roller applies a lubricant to the image carrier. The toner measuring unit measures an amount of toner transferred from the image carrier to the application roller. The control unit adjusts the supply of toner to be supplied to the image carrier in accordance with the amount of toner measured by the toner measuring unit.

An image forming apparatus includes a developer container to accommodate developer containing toner, a developer bearing member to rotate while bearing the developer accommodated in the developer container and develop the electrostatic latent image borne on an image bearing member into a developer image, a detection portion to output remainder amount information corresponding to an amount of the developer accommodated in the developer container, and a notification portion capable of notifying a first state indicating that a remainder amount of the developer accommodated in the developer container is a first amount or more and a second state indicating that the remainder amount of the developer accommodated in the developer container is less than the first amount. The notification portion notifies one of a plurality of states including the first state and the second state on a basis of the remainder amount information output from the detection portion.

A toner level detector includes a toner cartridge, an agitator, a reflective region, a first cleaner, a second cleaner and a transceiver. The toner cartridge stores toner, and has a light-permeable region. The agitator rotatably disposed in the toner cartridge agitates the toner. The reflective region is disposed on the agitator. The first cleaner is disposed on the agitator. The second cleaner is disposed on the toner cartridge. The transceiver disposed on a body outside the toner cartridge outputs an emitting signal to the reflective region through the light-permeable region. The reflective region reflects the emitting signal to generate a reflective signal received by the transceiver through the reflective region. The rotating first cleaner intermittently cleans the fixed light-permeable region, and the fixed second cleaner intermittently cleans the rotating reflective region.

A toner container includes a container main body, a conveying body, at least one first rotating body, and a second rotating body. The container main body has a compartment and an exit port. The compartment contains toner. The exit port allows the toner to be ejected from the compartment. The conveying body is located inside the compartment. The conveying body moves in a direction approaching the exit port while rotating to convey the toner to the exit port. The first rotating body engages with an outer circumferential surface of the conveying body and rotates according to rotation of the conveying body. The second rotating body rotates according to a first driving force generated by rotation of the first rotating body. The first rotating body is located at a prescribed position. The first rotating body rotates in response to the conveying body arriving at the prescribed position.

A powder storage height detection device includes: a main body that includes a transport path along which powder is transported; a powder transport unit that is disposed to rotate in the transport path and includes a transporter provided spirally around a rotational shaft; a swinging unit that comes into contact with a surface of the powder transported in the transport path, and swings by following at least a storage height of the surface; a detection unit that detects a state of swinging of the swinging unit; and a determination unit that determines presence or absence of the powder based on a detection signal outputted from the detection unit. The transport unit includes a non-transport portion in which the transporter is not present, and which is formed as an eccentric shaft having a shaft center displaced from the rotational shaft, the swinging unit is located and disposed to swing in the non-transport portion, and the determination unit samples the detection signal at an interval, and when a proportion of the detection signal lower than or equal to an output level becomes greater than or equal to a threshold value, outputs a signal indicating determination of absence of the powder, the interval being obtained by dividing a required time for one rotation of the transport unit by a predetermined number, the output level defining that the storage height is relatively low.

Provided is an image forming unit including a photosensitive unit including an image bearing member, a developing unit including a developer bearing member and a container capable of containing a developer, a rotation shaft, the developing unit being rotated around the rotation shaft and positioned at one of a development position where the developer bearing member supplies the developer to the image bearing member and a separation position where the developer bearing member separates from the image bearing member, and a sensing portion sensing a variation or an amount corresponding to an amount of the developer contained in the developing unit. The rotation shaft is located below a developing portion, which is formed of the image bearing member and the developer bearing member, in a gravity direction.

Provided is an image forming unit including a photosensitive unit including an image bearing member, a developing unit including a developer bearing member and a container capable of containing a developer, a rotation shaft, the developing unit being rotated around the rotation shaft and positioned at one of a development position where the developer bearing member supplies the developer to the image bearing member and a separation position where the developer bearing member separates from the image bearing member, and a sensing portion sensing a variation or an amount corresponding to an amount of the developer contained in the developing unit. When the developing unit is at the separation position, the sensing portion restricts the rotation of the developing unit thereby receiving a force from the developing unit.

An image forming apparatus includes: a detection unit configured to detect an amount of developer stored in a developing container and to output remaining amount information; and a control unit configured to perform control, during a replenishment of the developer to the developing container using, a replenishment container, to cause a display unit to display a message related to the replenishment. When the replenishment is instructed, the control unit is further configured to perform a first control during the replenishment in a case where the remaining amount information indicates a first remaining amount, and configured to perform a second control different from the first control during the replenishment in a case where the remaining amount information indicates a second remaining amount greater than the first remaining amount.

A powder storage height detection device includes: a main body that includes a transport path along which powder is transported; a powder transport unit that is disposed to rotate in the transport path and includes a transporter provided spirally around a rotational shaft; a swinging unit that comes into contact with a surface of the powder transported in the transport path, and swings by following at least a storage height of the surface; a detection unit that detects a state of swinging of the swinging unit; and a determination unit that determines presence or absence of the powder based on a detection signal outputted from the detection unit. The transport unit includes a non-transport portion in which the transporter is not present, and which is formed as an eccentric shaft having a shaft center displaced from the rotational shaft, the swinging unit is located and disposed to swing in the non-transport portion, and the determination unit samples the detection signal at an interval, and when a proportion of the detection signal lower than or equal to an output level becomes greater than or equal to a threshold value, outputs a signal indicating determination of absence of the powder, the interval being obtained by dividing a required time for one rotation of the transport unit by a predetermined number, the output level defining that the storage height is relatively low.