A toner container information acquiring method includes: measuring a toner amount contained in a resin forming a toner container; and acquiring information regarding mechanical strength of the toner container based on the measured toner amount.

An image forming apparatus includes a motor, a container detection sensor, and a controller. When a toner container is attached, the motor generates a driving force for rotating a toner conveying member in the toner container. The container detection sensor is arranged at a position where the container detection sensor comes into contact with an outer periphery of a cam connected to the toner conveying member when the toner container is attached. The controller distinguishes between at least three attachment states of the toner container based on a sensor signal of the container detection sensor.

A processor causes a printing portion to execute test image transfer processing for transferring a plurality of test toner images onto an area outside a secondary transfer area on a surface of an intermediate transfer member, and secondary voltage stop processing for stopping a supply of a secondary transfer voltage. The processor acquires a plurality of first sensing densities. The processor causes the printing portion to execute the test image transfer processing and secondary voltage supply processing for supplying the secondary transfer voltage. The processor acquires a plurality of second sensing densities. The processor compares the plurality of first sensing densities and the plurality of second sensing densities to determine a state of a toner charging amount in each of the plurality of test toner images.

A remaining-toner-amount detecting device includes: first sensor disposed at a supply channel for a toner; a second sensor disposed at a location different from the supply channel; detection processing that compares a capacitance detected by the first sensor with a determination threshold value to detect a toner end; and a memory that stores a capacitance detected by the second sensor in an initial period as initial reference data, and a capacitance detected by the second sensor after part replacement as post-replacement reference data. The detection processing circuitry sets, based on the initial reference data, the determination threshold value as an initial determination threshold value in the initial period, and re-sets the determination threshold value, from the initial determination threshold value, to a value based on the post-replacement reference data, as a post-replacement reference data after the part replacement.

An image forming apparatus includes a latent image forming portion configured to form a latent image on an image bearing member; a developing device including a container configured to store toner and a developing member configured to supply the toner to the latent image formed on the image bearing member to form a toner image; an environment sensor configured to detect environmental information related to an environment in which the developing device is placed; and a controller configured to control switching between a first mode and a second mode, in which a number of prints per unit time is less than that in the first mode. The controller is configured to perform switching from the first mode to the second mode based on an update value obtained by adding or subtracting over time an index value weighted in accordance with the environmental information detected by the environment sensor.

An evaluation device evaluates an image clarity of a print image. The evaluation device includes: an object that is projected onto a measurement surface of a recording medium; an illuminator that makes the object projected onto the measurement surface; an imager that images the measurement surface on which the object has been projected to obtain image data; and a hardware processor that, based on a distribution of parameters related to a brightness of the image data, quantifies a degree of the image clarity into a numerical value and defines the numerical value as an evaluation value of the image clarity.

An image forming apparatus, includes: plural image forming units each including an image holding member and configured to form an image that is to be transferred to a recording medium on the image holding member using a dry toner, the number of the plural image forming units being at least five; and plural developing devices each of which is provided in each of the plural image forming units and supplied with the dry toner and a dry carrier, each of the plural developing devices including a dry toner adhering unit that has a length equal to or longer than a length of a long side of an A3 size and to which the dry toner adheres, the dry toner adhering unit being configured to cause the dry toner adhering to the dry toner adhering unit to adhere to the image holding member.

An image forming apparatus includes an image forming unit configured to form an image, a reader having a transparent member, the reader being configured to read an original through intermediation of the transparent member, a document feeder configured to feed the original in order to read the original by the reader, a reader image processor, and a controller. The controller is configured to control the image forming unit to form a test chart on a sheet, to control the reader image processor to detect the dust on the transparent member based on a result of reading the test chart, and to generate a conversion condition based on other signal values excluding an abnormal signal value caused by the dust on the transparent member.

A powder transport device includes: a rotation shaft rotatably supported in a container chamber that contains powder; and plural blade members detachably attached to the rotation shaft, the blade members including spiral blades configured to transport the powder in an axial direction of the rotation shaft in response to the rotation shaft rotating.

An image forming apparatus that is replenished with toner by using a toner cartridge serving as a toner container that accommodates toner, which is a consumable, and that is detachable from an apparatus body, includes, as a characteristic component of a control section that controls the image forming apparatus, a display control unit that, when a toner cartridge to be first inserted or a replacing toner cartridge is inserted, causes a display section of an operation panel to display a display (e.g. a message, an image (illustration), a moving image, or the like) that instructs a user in an operation of shaking the toner cartridge.