An accumulation device includes a container, an expansion mechanism, and a detector. The container has an opening through which the container receives powder. The expansion mechanism includes a separator which separates an interior of the container into a first space where the powder dropped through the opening is accumulated and a second space where the powder dropped through the opening is not accumulated. The expansion mechanism allows the first space to be enlarged by changing a state of the separator. The detector detects the powder accumulated in the first space.

A developing device includes: a toner detection unit that detects whether there is toner that is stored; a stirring unit that stirs toner in a toner container; a calculation unit that calculates an output duty by comparing an output voltage of the toner detection unit representing whether there is toner after the stirring, with a predetermined voltage value; and a remaining amount detection unit that detects an amount of remaining toner at the output duty from a correspondence relationship between the output duty and an amount of remaining toner that is previously set.

A cartridge configured to accommodate a developing agent may include a detection gear, a first protrusion, and a memory. The detection gear may be rotatable about a first axis extending in a predetermined direction. The first protrusion may be movable with rotation of the detection gear. The memory may include a first storage region storing a first yield information representing at least one of amount of the developing agent in the cartridge and the number of printable sheets by the developing agent in the cartridge, wherein at least one of the amount of the developing agent and the number of sheets by the developing agent in the cartridge may be confirmable based on the first yield information and the first protrusion.

An apparatus includes an image bearing member, a developer container having a replenishment port, a developer bearing member, a detection portion configured to output remainder amount information corresponding to the amount of developer accommodated in the developer container, a notification portion capable of notifying a first state, and a second state, and a control portion, wherein the maximum amount of the developer that the developer container is capable of accommodating is larger than a value obtained by adding the amount of the developer accommodated in a replenishment container containing the developer for replenishment to the first amount, and wherein notification of the second state corresponds to notification of a case where the amount of the developer remaining in the developer container is larger than a case where the amount of the developer remaining in the developer container is the smallest.

An operation status prediction system includes a hardware processor. The hardware processor acquires data, which is relevant to an operation status at each timing of an operation device to be monitored, so as to be associated with information of the timing. The hardware processor predicts a future operation status according to the acquired operation status for each of a plurality of periods having different lengths from the present.

An example operation method of an image forming apparatus includes obtaining, through a sensor in the image forming apparatus, toner data corresponding to an amount of toner remaining in a developing apparatus, obtaining, based on the toner data in every predetermined period, a linear prediction model predicting the amount of toner remaining in the developing apparatus according to a time at which the toner is supplied to the developing apparatus, predicting, based on the linear prediction model, an expected supply time required for the amount of toner remaining in the developing apparatus to reach a target level, and controlling an operation of supplying the toner to the developing apparatus according to a result of comparing the expected supply time with a predetermined reference supply time.

A stored object detection device includes: a radar sensor which emits a radio wave and detects a reflected wave; a reflector which reflects the radio wave emitted from the radar sensor; and a detection target object storage amount detector which detects a storage amount of a detection target object in a container, based on a reflected wave of the radio wave that has been reflected on the container containing the detection target object, a reflected wave of the radio wave that has passed through the container and has been reflected on the detection target object, and a reflected wave of the radio wave that has passed through the container and has been reflected on the reflector.

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 system includes a recording processing portion, an acquirement processing portion, and an output processing portion. The recording processing portion records a consumed amount of a consumable consumed by an image forming apparatus per predetermined unit time. The acquirement processing portion acquires prediction data that indicates a predicted consumed amount of the consumable per the unit time for a time period from a predetermined standard time, based on a comparison result between: a first record result corresponding to a first time period extending to a reference time; and a second record result corresponding to a predetermined second time period extending to the standard time, among a record result recorded by the recording processing portion, the reference time being a predetermined specific time period earlier than the standard time. The output processing portion outputs the prediction data acquired by the acquirement processing portion.