Provided is an image formation device including a photoreceptor configured to carry a toner image and a developer configured to form the toner image on a surface of the photoreceptor and configured such that the developer is a replaceable development unit, the image formation device including: a development bias application section configured to apply a development bias to between the photoreceptor and the developer; a stabilization control section configured to perform image stabilization control of determining a development bias value to be used in future by changing the development bias while measuring a density of the toner image formed by the developer, thereby obtaining the toner image with a target density; and a life determination section configured to determine expiration of use of the development unit when the development bias value determined by the stabilization control falls outside a preset acceptable range.

A method of adjusting an imaging apparatus comprises printing a set of test patches, the set of test patches comprising a solid color patch, a grey level patch and a substrate patch. The optical densities of the set of test patches are determined. The method comprises simultaneously correcting a solid optical density value (Solid OD), relating to the solid color patch and an associated grey level (LUT) value relating to the grey level patch.

An image forming apparatus includes an image forming device, an image position detector, and an image density detector. The image forming device forms an image on a surface of a recording medium. The image position detector detects a position of the image. The image density detector detects a density of the image. The image forming device forms a position detection image on a surface of a first recording medium. The image position detector detects a position of the position detection image on the surface of the first recording medium. The image forming device forms a density detection image on a second recording medium. The image density detector detects a density of the density detection image on the surface of the second recording medium.

An image reading device includes a light applying unit that applies light from a light source to a recording medium, a detecting unit that detects the light reflected by the recording medium, a holding member that is movable in a first scanning direction of the light applying unit and holds a calibration member to which the light from the light applying unit is applied, a shaft member that extends in the first scanning direction through the holding member and guides the movement of the holding member in the first scanning direction, and a restricting member that extends in the first scanning direction and restricts rotation of the holding member about the shaft member.

A spectral colorimetric apparatus comprises a light source, a spectral element, a light receiving element, a substrate on which the light receiving element is mounted, a housing and a pressing portion. The housing has a first side wall on which the substrate is fixed and a second side wall on which the spectral element is fixed. The pressing portion pinches the spectral element together with the second side wall and presses the spectral element to the second side wall.

An image forming apparatus according to an embodiment includes an image forming unit, and a processor. The image forming unit forms an image on a printing medium. The processor performs user authentication and, upon performing the user authentication, determines whether or not an image stabilization process should be performed in the image forming unit. The processor then instructs the image forming unit to perform the image stabilization process according to a result of the user authentication.

A density correction unit calculates a density change rate to a change in an exposure amount as a first density change rate based on a difference between a density of a part of reference patch images, in which a position in a main scanning direction is identical to a position of a first patch image. As for a second patch image, the density correction unit similarly calculates a second density change rate. A light amount when forming the first patch image is smaller than a reference light amount. A light amount when forming the second patch image is larger than the reference light amount. The density correction unit uses the first or the second density change rate based on whether a density of each position of the reference patch images in the main scanning direction higher or lower than a target density to correct the exposure amount

There is provided a printing apparatus. The printing apparatus includes: a memory storing a program; and at least one hardware processor configured to execute a process in the program. The process includes: performing pre-printing of overprinting which is an operation of performing pre-printing on a medium and then performing post-printing on the medium; and printing a chart asymmetric with respect to rotation toward a direction of the medium on the medium during test printing related to the pre-printing.

Disclosed is an image forming apparatus, including: a job receiver that receives a print job; a printer that executes an image forming in accordance with the print job received by the job receiver; and a hardware processor that: receives an adjustment content and a setting of an execution starting condition of an adjustment for an adjustment item relating to the image forming, and registers the adjustment content and the execution starting condition as a profile; and executes the adjustment in accordance with the adjustment content set in the registered profile when the execution starting condition set in the profile is satisfied.

An image forming apparatus includes an identification-mark making unit. The identification-mark making unit makes a page identification mark for identifying a page, on a predetermined position of a paper sheet during printing. The identification-mark making unit, based on the page identification mark made in a previous printing, includes a correction/addition mark that indicates an existence of a correction page or an additional page since the previous printing in a part of the page identification mark when a new print output is performed.