An image forming apparatus includes a photosensitive drum, a developing device, a transfer unit, an image sensor configured to detect a toner image on the transfer unit, and a processor. The processor is configured to determine whether the remaining amount of toner in a toner cartridge has decreased to a predetermined level or below. The processor is configured to carry out an image quality stabilization process when the remaining amount of toner is above the predetermined level. The image quality stabilization process being based on a detection result from the image sensor detecting a test pattern formed on the transfer unit. The processor is further configured to perform print process without performing an image stabilization process, without carrying out the image quality stabilization process.

An image forming apparatus includes a first sensor configured to measure a measurement image on a first photoreceptor, a second sensor configured to measure a measurement image on an intermediate transfer member, and a controller. The controller controls the first image forming unit to form first measurement images, wherein the first measurement images are formed along a rotation direction of the first photoreceptor, and controls the first sensor to measure the first measurement images on the first photoreceptor. The controller further controls the first image forming unit and the second image forming unit to form a plurality of measurement images while a rotation speed of the first photoreceptor is being controlled based on a measurement result of the first sensor, wherein the plurality of measurement images is formed along the predetermined direction of the intermediate transfer member.

According to one embodiment, there is provided a toner cartridge used in an image forming apparatus including a processor which forms a toner pattern image on a photoconductive member, transfers the toner pattern image on a medium, and changes an image forming condition based on a detection result obtained by optically detecting the toner pattern image transferred onto the medium, the toner cartridge including: a toner accommodating container accommodating a toner, and a memory. The memory stores reference data which is determined according to toner characteristics in the toner accommodating container, and is used for applying a reference value for an optical detection result of a toner pattern formed by the toner on the medium.

This disclosure relates to a method, apparatus, and system for determining image quality of a printer or similar image forming device. A first graphic pattern and a second graphic pattern may be printed on sets of N1 test pages. The second graphic pattern may have the same colorant coverage as the first graphic pattern, though the two patterns may have different orientations and different locations on the page. The patterns may partially overlap in page location. Total colorant coverage may be compared between the set of N first test pages and the set of N second test pages. If the colorant coverage is different between the sets, the image forming device may be assigned an abnormal operating status.

According to one embodiment, there is provided a toner cartridge used in an image forming apparatus including a processor which forms a toner pattern image on a photoconductive member, transfers the toner pattern image on a medium, and changes an image forming condition based on a detection result obtained by optically detecting the toner pattern transferred onto the medium, the toner cartridge including: a toner accommodating container accommodating a toner, and a memory. The memory stores a plurality of reference data which are determined according to toner characteristics in the toner accommodating container and a value indicating an image forming execution amount, and are used for applying reference values for an optical detection result of a toner pattern formed by the toner on the medium.

An image forming apparatus includes image forming units, secondary transfer units, and first and second detection devices. Each image forming unit includes image forming devices, and a primary intermediate transfer body. Toner images formed by the image forming devices are primarily transferred to the primary intermediate transfer body. The secondary transfer units are provided for the image forming units, respectively. Each secondary transfer unit is configured to secondarily transfer the toner images on a corresponding one of the primary intermediate transfer bodies to a transfer body. The first detection device is configured to detect the toner images downstream of the most downstream secondary transfer position. The second detection device is provided in at least one of the image forming units. The second detection device is configured to detect the toner images between the most downstream primary transfer position in the primary intermediate transfer body and a secondary transfer position.

An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit forms a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias, acquires a tilt of a measurement straight line representing a relationship between the change amount of the frequency and a density change amount of the measurement toner image based on the change amount of the frequency and a result of detecting density of the measurement toner image in the density detecting unit, and acquires the charging amount of the toner based on the acquired tilt of the measurement straight line and the reference information in the storage unit.

A method of stabilizing a marking process speed in a printing system, the printing system including a vacuum transport belt and at least one sheet onto which marking material is directly applied to print sheets, the method including printing an image on the sheet, receiving, from a sensor, data related to the image, determining, based on the data, at least one actual dimension of the image, determining if the at least one actual dimension of the image is equal to a target dimension of the image, and if the at least one actual dimension is not equal to the target dimension, adjusting one or more components of the printing system.

An image forming apparatus includes: an image former that divides a first image into a plurality of second images and forms the second images on an image carrier; a test image reader that reads the second images formed on the image carrier; and a hardware processor that: selects a number of the second images from among the second images read by the test image reader, the number of the second images being smaller than a number of division of the first image; combines the selected second images into a combined image; and detects an image defect in the combined image.

An image forming apparatus includes: a photoreceptor that forms a toner image on a surface of the photoreceptor; a charger that charges the surface of the photoreceptor; an exposure device that exposes the surface of the photoreceptor; a developer that supplies toner to the surface of the photoreceptor; an intermediate transfer belt for transferring the toner image formed on the surface of the photoreceptor; a density sensor that detects a density of the toner image on the intermediate transfer belt; and a controller that controls the image forming apparatus.