A developing unit includes a body and a displacement member. The displacement member is to be held by the body in a first mode in a first mounting state, and is to be held by the body displaceably between the first mode and a second mode in a reversible fashion in a second mounting state. The first mounting state is a state in which a first toner cartridge is mounted on the developing unit. The second mounting state is a state in which a second toner cartridge is mounted on the developing unit.

An exposure device includes an exposure section, a weight, and an elastic portion. The exposure section includes plural light emitting elements arranged along an axial direction of an image holding member that is rotatable, is positioned with respect to the image holding member at both ends in the axial direction, and exposes the image holding member to light by emitting light to the image holding member. The weight is disposed so as to face the exposure section, and has a mass determined in advance. The elastic portion is elastic, and is disposed between the exposure section and the weight to support the weight so as to be vibratable.

An image forming apparatus includes plural image preparing units whose attachment positions are selectable and that prepare images of respective colors; and a setting unit that, in a case where an attachment position of a first image preparing unit, which is any one of the plural image preparing units, is changed from a first attachment position to a second attachment position different from the first attachment position, sets, for the first image preparing unit in the second attachment position, first setting information that is different from first setting information set for the first image preparing unit while the first image preparing unit is attached in the first attachment position and second setting information that is identical to second setting information set for the first image preparing unit while the first image preparing unit is attached to the first attachment position.

A linkage device for a toner supply container includes: a transverse linkage, which comprises a rod body and a jaw portion, wherein the jaw portion is connected to a front end of the rod body; and a longitudinal linkage, wherein a first end of the longitudinal linkage is rotatably coupled to the rod body of the transverse linkage. A mounting and conveying device for the toner supply container includes: the linkage device and a cover body, wherein a first connecting post and a third connecting post are arranged on a side face of the cover body; wherein a second end of the longitudinal linkage is rotatably fixed to the first connecting post, and a spring post is connected to the third connecting post by a tension spring. Such structure is well sealed and simple with less wear on the parts.

An image formation apparatus includes an image bearing member on which an electrostatic latent image is formed and a developing agent bearing member configured to carry a developer used to develop the electrostatic latent image formed on the image bearing member. The image formation apparatus forms an image by using the electrostatic latent image formed on the image bearing member. The image formation apparatus further includes an obtaining unit configured to obtain the information about a rotation speed of the image bearing member and a rotation speed of the developing agent bearing member; a determination unit configured to determine, according to the obtained information, a color conversion table used to transfer and record the input image data; and an image formation unit configured to convert a signal of the input image data according to the determined color conversion table and form an image with the converted signal value.

An electric field sensor has a semiconductor stack, a first electrode, and a second electrode. The semiconductor stack includes a first semiconductor layer of a first conductive type and a second semiconductor layer of a conductive type opposite to the first conductive type stacked on the first semiconductor layer. The first electrode is arranged on one side of the semiconductor stack in the lamination direction. The second electrode is arranged on the other side of the semiconductor stack in the lamination direction. The electric field sensor detects the intensity of an electric field in the direction orthogonal to the lamination direction based on a current passing through the semiconductor stack.

An image forming apparatus includes: a transfer member that transfers a toner image to a continuous sheet, the transfer member having a lower hardness than a member opposed thereto with the continuous sheet therebetween when the continuous sheet is transported; and a moving unit that moves the transfer member in a direction intersecting the direction in which the continuous sheet is transported.

An image formation apparatus includes an image bearing member on which an electrostatic latent image is formed and a developing agent bearing member configured to carry a developer used to develop the electrostatic latent image formed on the image bearing member. The image formation apparatus forms an image by using the electrostatic latent image formed on the image bearing member. The image formation apparatus further includes an obtaining unit configured to obtain the information about a rotation speed of the image bearing member and a rotation speed of the developing agent bearing member; a determination unit configured to determine, according to the obtained information, a color conversion table used to transfer and record the input image data; and an image formation unit configured to convert a signal of the input image data according to the determined color conversion table and form an image with the converted signal value.

An image forming apparatus includes an image forming section to form a correction pattern, a reading unit to read the pattern and generate first data, a color converter to convert the first data into second data, a memory to store density conversion data for a recording medium, a determiner to determine whether the memory contains the conversion data for the recording medium the pattern is formed, an acquisition unit to acquire spectral measured by an external colorimeter the memory does not contain the conversion data, a first density converter to convert the spectral data into density data, a density conversion data generator to correlate the second data and the density data and generate the conversion data, a second density converter to convert the second data into the density data using the conversion data, and a correction curve generator to generate correction curve data based on the density data.

A unit accommodation apparatus includes a first unit and a second unit that are to be installed into and removed from an apparatus body through an opening in an installation-removal direction and are held by a unit holder. The unit holder includes a first positioner that is disposed opposite one lateral end of the first unit and the second unit and is detachably attached to the first unit and the second unit. A second positioner is disposed opposite another lateral end of the first unit and the second unit and holds the first unit and the second unit in a state in which the first unit and the second unit are detachably attached to the second positioner. The first positioner and the second positioner secure a relative position of the first unit relative to the second unit in a direction parallel to a hypothetical orthogonal plane perpendicular to the installation-removal direction.