An image forming apparatus includes an image forming portion, a supply processing portion, and a second release processing portion. The image forming portion includes a storing portion that stores developer, and forms an image by using the developer stored in the storing portion. The supply processing portion supplies the developer to the storing portion from a developer storing portion attached to an attachment portion, when a storage amount of the developer in the storing portion is less than or equal to a first threshold. The second release processing portion releases regulation on a removal of the developer storing portion when an expected amount of developer to be used by a user is greater than or equal to a reference value that is determined based on a remaining amount of the developer in the developer storing portion attached to the attachment portion.

A cartridge is configured to be attachable to a main body of an image forming apparatus and configured to receive toner supplied from a supply container. The cartridge includes a supply port configured to receive the toner supplied from the supply container, a shutter member configured to cover the supply port, and a locking member. The locking member is moved from a lock position to an unlock position to allow movement of the shutter member by using electric power supplied from the main body.

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.

The control unit controls supply of toner from the toner container to the developing device. The control unit is capable of executing a normal supply in which toner is supplied from the toner container to the developing device based on a detection result of the toner amount detection sensor, and a toner installation mode in which a larger amount of toner than the normal supply is supplied from the toner container to the developing device. When the toner installation mode is selected, the control unit calculates a toner amount T1 required for executing the toner installation mode and a toner remaining amount T2 in the toner container, and prohibits the execution of the toner installation mode when T1>T2.

A system comprises: an obtaining unit that obtains predetermined information relating to amount of printing materials for a tank attached to a printing apparatus; and a determining unit that determines an interchangeable tank to be provided from a plurality of types of interchangeable tanks based on the predetermined information, wherein the plurality of types of interchangeable tanks include a first tank and a second tank, the first tank contains printing materials of at least two colors, with a ratio of amounts of the printing materials of the at least two colors being a first constituent ratio, and the second tank contains printing materials of at least the same two colors as those in the first tank, with a ratio of amounts of the printing materials of at least the two colors being a second constituent ratio different from the first constituent ratio.

When, in a state where a developer borne by a developer bearing member is sandwiched by an opposing portion of an image bearing member and the developer bearing member, C denotes capacitance between the image bearing member and the developer bearing member, ΔV denotes a development contrast, Q/S denotes a charge amount per unit area of the developer borne by the developer bearing member, and Δv denotes a peripheral velocity ratio which is a ratio of a peripheral velocity of the developer bearing member to a peripheral velocity of the image bearing member, a first peripheral velocity ratio is set so that |Q/S×Δv|≦|C×ΔV| is satisfied, and a second peripheral velocity ratio which is larger than the first peripheral velocity ratio is set so that |Q/S×Δv|>|C×ΔV| is satisfied.

Changing of a peripheral speed ratio, resulting in change of the developer amount per unit area, enables the detection unit to detect the developer amount with sufficient accuracy.

A logic circuitry package for a replaceable print apparatus component comprises an interface to communicate with a print apparatus logic circuit, and at least one logic circuit. The logic circuit may be configured to identify, from a command stream received from the print apparatus, parameters including a class parameter, and/or identify, from the command stream, a read request, and output, via the interface, a count value in response to a read request, the count value based on identified received parameters.

An image forming apparatus comprises a controller, an adjustment unit configured to adjust an image forming condition based on an adjustment condition corresponding to a profile of a toner adhesion amount in a sheet conveying direction, and an image forming unit configured to form an image on a sheet with the adjusted image forming condition while conveying the sheet.

A powder transfer device includes: a holder that detachably holds a powder applicator that applies a powder to an image; and a transfer part that transfers the powder onto the image from the powder applicator held by the holder, wherein the powder applicator having the powder adhering to a surface is mounted to the holder.