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.

An image forming apparatus is provided, including a conveying member configured to convey a long paper along a paper path; an image forming unit which forms an image on the long paper being conveyed by the conveying member along the paper path; an image reading unit which reads a surface of the long paper, the surface having the image formed by the image forming unit; and a color sample member which is arrangeable at a position facing the image reading unit, such that the long paper is conveyed by the conveying member to avoid passing through between the image reading unit and the color sample member. Also included is a switch between a first arrangement in which the image reading unit reads the long paper and a second arrangement in which the image reading unit faces the long paper via the color sample member and reads the color sample member, the switch being made by moving the image reading unit or by moving the color sample member and the conveying member.

An image forming apparatus includes a photosensitive member, a charging roller, an exposure device, a developing device, a transfer member, a fixing device, a voltage source for output the charging voltage, an executing portion for forming a test chart including a plurality of adjusting images in setting of peak-to-peak voltage values of AC voltages at a plurality of different values, a first inputting portion through which an instruction of execution of forming the test chart is inputted, and a second inputting portion through which an instruction of setting a value of peak-to-peak voltage values of the AC voltage during image formation is inputted.

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.

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.

An image processing apparatus includes a memory, a scanner, and a processor configured to: control the scanner to read an image formed on a sheet along a reading direction, and store data of the read image in the memory, determine a plurality of regions of the image, select one of the regions based on a whiteness or saturation level of color thereof, and add a first image indicating the reading direction to said one of the regions, and store data of the image to which the first image has been added in the memory.

In the image forming method, a halftone image is generated by performing halftone processing for an input image, a scanned image of a printed material on which on which the halftone image is printed is obtained, and a failure component of an image forming apparatus is identified based on a difference between the scanned image and the input image. In the generation, the halftone image is generated by representing a dot pattern of a halftone portion in a case where the input image is a test image for the failure diagnosis by a dot pattern whose frequency is relatively higher than that of a dot pattern that is applied to the halftone portion in a case where the input image is an image other than the test image.

An image forming apparatus is provided, including a conveying member configured to convey a long paper along a paper path; an image forming unit which forms an image on the long paper being conveyed by the conveying member along the paper path; an image reading unit which reads a surface of the long paper, the surface having the image formed by the image forming unit; and a color sample member which is arrangeable at a position facing the image reading unit, such that the long paper is conveyed by the conveying member to avoid passing through between the image reading unit and the color sample member. Also included is a switch between a first arrangement in which the image reading unit reads the long paper and a second arrangement in which the image reading unit faces the long paper via the color sample member and reads the color sample member, the switch being made by moving the image reading unit or by moving the color sample member and the conveying member.

The image forming apparatus includes: a paper feed unit; a print unit; a registration roller; a sheet leading end sensor provided downstream, in a transport direction of the recording paper, of the registration roller; a time measuring unit for measuring a time from a start point of transportation of the recording paper by the registration roller to a point of detection of the leading end of the recording paper by the sheet leading end sensor; a memory unit for storing a reference image forming time and a reference time; a print control unit; and an arithmetic unit for obtaining a difference between the reference time and the time detected by the time measuring unit. The print control unit adjusts the length of the image forming period in accordance with the adjusted image forming time determined based on the difference obtained by the arithmetic unit and the reference image forming time.

An image forming apparatus includes a printing device to perform normal printing of a job according to a setting, and processing circuitry to: accept a request for executing printing of another job while the printing device is performing the normal printing of the job according to the setting; when the request for executing printing of another job is a request for executing trial printing, control the printing device to interrupt the normal printing of the job to perform the trial printing of the another job; and control an ejection device to discharge a recording medium printed in the normal printing of the job and a recording medium printed in the trial printing of the another job on different sheet discharge trays.