An image forming apparatus includes a first printer configured to print on a medium using a first material, a second printer configured to print on the medium using a second material that turns invisible when a first condition is satisfied, and a controller configured to: control the first printer to print on the medium a first symbol that is machine-readable and associated with first information, and control the second printer to print a second symbol on the medium on which the first symbol has been printed. A composite symbol of the first and second symbols is machine-readable and associated with second information different from the first information.

An image reading apparatus capable of detecting correct color tones of an image printed on a sheet is described. The image reading apparatus includes a scanner 100, a colorimeter 103, a cooling device 145, a temperature control unit 111, and an image correction unit 113. While an image correction process is not performed, the temperature control unit 111 controls the cooling temperature to a first temperature for shifting the cooling device 145 to a predetermined cooled state. While the image correction process is performed, the temperature control unit 111 controls the cooling temperature to a second temperature for making the temperature of the sheet uniform. The image correction unit 113 obtains, while the temperature control unit 111 controls the cooling temperature to the second temperature, the correction amount of the image based on the colorimetric measurement result of the colorimeter 103 and the reading result of the scanner 100.

A controller provided in a control device calculates an index value indicative of an amount of a specific type of ink in a specific type of color to be used in printing at least a part of a target image including a first image and a second image. In response to determining that the index value is not greater than a threshold value, the controller controls a printer to print the first image and the second image using the specific type of ink for reproducing the specific type of color. In response to determining that the index value is greater than the threshold value, the controller controls the printer to print the first image using the specific type of ink and to print the second image using a different type of ink different from the specific type of ink for reproducing the specific type of color.

An image forming apparatus includes: an image forming section; an image reading sensor and a colorimeter; a temperature sensor; a memory that stores a first color value and a second color value in a first color chart that has a larger number of patches than a second color chart; a processor that creates a scanner profile for converting a first color value into a second color value using color values obtained by the image reading sensor and the colorimeter, corrects the scanner profile according to the color values obtained by the image reading sensor and the colorimeter, and converts the first color value into the second color value using the corrected scanner profile.

An image forming apparatus, including: an image forming unit configured to form an image; an adjustment unit configured to select a type of adjustment processing, and execute the selected type of adjustment processing for the image forming unit; and a determination unit configured to determine an adjustment time based on the selected type of adjustment processing, wherein the determination unit determines, in a case where the adjustment unit causes the image forming unit to stop the image forming operation for executing the selected type of adjustment processing in a downtime, a first adjustment time, and wherein the determination unit determines, in a case where the image forming unit has finished the image forming operation, a second adjustment time longer than the first adjustment time.

The invention relates to a system and method for adjusting the color of image objects based on chained reference points and/or light gradients to account for the effects of lighting conditions that can vary across different environments, according to an implementation of the invention. To chain reference points and/or characterize light gradients, the system may determine a color shift value, which represents the effects of lighting conditions of a target environment (in which the lighting conditions may be unknown) relative to a reference environment (in which the lighting conditions may be known). The chained reference points, gradient characterization, color shift values, and/or other information may be used to store a delta map that characterizes the lighting conditions of an environment so that it may be reused for subsequent color shifts without re-characterizing the environment.

A controller provided in a control device calculates an index value indicative of an amount of a specific type of ink in a specific type of color to be used in printing at least a part of a target image including a first image and a second image. In response to determining that the index value is not greater than a threshold value, the controller controls a printer to print the first image and the second image using the specific type of ink for reproducing the specific type of color. In response to determining that the index value is greater than the threshold value, the controller controls the printer to print the first image using the specific type of ink and to print the second image using a different type of ink different from the specific type of ink for reproducing the specific type of color.

In an image forming apparatus including multiple light emitting elements, upon receiving an instruction from a user to execute correction (first correction) of a phase shift due to a shift in the relative positions of an optical scanning apparatus and the photosensitive member, a CPU executes correction (second correction) of a phase shift due to temperature change in the image forming apparatus. Thereafter, the CPU performs image formation control such that a phase adjustment image is formed on a recording medium, and determines a phase adjustment value based on an adjustment value input by the user. The CPU sets the phase adjustment value in the optical scanning apparatus to correct the phase shift. Thus, when the first correction is to be executed, the CPU executes the second correction before executing the first correction.

An image forming apparatus is provided, which is capable of implementing updating of gamma correction information with a high accuracy while avoiding a wasteful output of a patch image even in the case where environmental fluctuations occur. The image forming apparatus corrects a density tone level of image data by using gamma correction information, forms an image based on the corrected image data, and includes an updating unit configured to update the gamma correction information by using a patch image, and the updating unit updates the gamma correction information by using a patch image the output stability of which is high as first updating and further updates the gamma correction information updated by the first updating by using a patch image the sensitivity of which is high as second updating.

An image forming apparatus includes a detection portion that detects an earthquake, a plurality of job execution portions that each execute a job, an output portion that outputs information, and a control portion that, upon the detection portion detecting the occurrence of an earthquake, switches a mode of the image forming apparatus to an emergency mode, after a lapse of a prescribed wait time since the switching to the emergency mode, executes a self-diagnosis process for checking whether or not the job execution portions operate properly, and based on a result thereof, makes an output portion output information indicating an executable job and a non-executable job.