Abstract: An image forming apparatus includes a second acquisition processing portion and a third acquisition processing portion. The second acquisition processing portion acquires a first toner image forming condition of a toner image forming portion. The third acquisition processing portion acquires, based on the first toner image forming condition acquired by the second acquisition processing portion, a relational expression that indicates a relationship between a second toner image forming condition of the toner image forming portion and a toner concentration of a specific toner image that is formed by the toner image forming portion. Further, the third acquisition processing portion uses specific expressions that respectively correspond to a plurality of coefficients included in the relational expression to calculate the plurality of coefficients corresponding to the first toner image forming condition acquired by the second acquisition processing portion.

Abstract: A control device selects one of a plurality of chromatic colors as a target chromatic color according to a consumption status of developing agents of the plurality of chromatic colors. The control device causes an image forming portion to execute a process of forming, on a surface of a transfer medium, a plurality of chromatic color test images of the plurality of chromatic colors, and a superimposed test image in which a black test image is superimposed on a background image of the target chromatic color. The control device acquires a test detection signal of an amount of diffuse reflection light in each of areas of the plurality of chromatic color test images and the superimposed test image on the surface of the transfer medium. The control device adjusts timing of image formation of the plurality of colors by the image forming portion based on the test detection signal.

Abstract: An image forming apparatus includes an image forming portion, an exposure device, an image density sensor, and a control portion. The control portion can, by adjusting the development voltage based on the image density of a reference image and the amount of exposure from the exposure device, perform image density correction to adjust the image density. The control portion predicts the toner charge amount based on a formation condition of the reference image and the image density of the reference image and determines the timing of performing the image density correction next time based on the rate of change of the toner charge amount calculated using a first toner charge amount predicted when the image density correction was performed last time, a second toner charge amount predicted when the image density correction is performed this time, and the interval between the image density correction performed last time and this time.

Abstract: An image forming apparatus includes an image forming device, a controller, a density measurement device, and a calculator. The calculator detects a relationship (approximation line L1) between a control amount CV related to an image forming operation and a density D of an image formed on a photoconductor drum, which is an image carrier, and calculates a set value CV_TD of the control amount CV corresponding to a target density TD on the basis of the relationship. The controller forms a patch image on the photoconductor drum by using the set value CV_TD. The calculator calibrates the relationship on the basis of a difference ?D between a density D10 of the patch image and the target density TD, and corrects the set value CV_TD on the basis of the calibrated relationship.

Abstract: An image forming apparatus includes a first image processing portion and a second image processing portion. In a double-sided printing process that forms a print image on a front side and a back side of a sheet, the first image processing portion executes a print image forming process corresponding to the front side and the print image forming process corresponding to the back side under different image forming conditions. In a case in which a detection image forming process is executed during execution of the double-sided printing process, the second image processing portion executes the detection image forming process only under the image forming conditions in the print image forming process corresponding to a predetermined one of the front side and the back side.

Abstract: An optical system used in an optical apparatus is configured to include a first lens group having positive refractive power, a focusing group that moves along an optical axis at focusing, and a rear group, in order from an object side, so that the first lens group includes a first-A lens group disposed on the object side of the largest air space A in the first lens group, and that all of the following conditional expressions are satisfied: 1. < FNo × ( TL / f ) 2 < 2.5 and 0.3 < dA / dG ? 1 < 0.85 where FNo is the f-number of the optical system focusing on infinity, TL is the total optical length of the optical system focusing on infinity, f is the focal length of the optical system focusing on infinity, dA is the length on the optical axis of the air space A, and dG1 is the length on the optical axis of the first lens group.

Abstract: In an image forming apparatus, an adjustment processing portion allows, in a case where a printing type of a print process to be executed by a print processing portion is changed from either monochrome or color printing, a condition adjustment process of adjusting an image formation condition of an image forming portion to be executed before execution of the monochrome or color printing subsequent to a change of the printing type. The print processing portion allows line speed of the image forming portion to be changed depending on a combination of a line speed mode and the printing type set in association with a sheet type of a sheet. In addition, the adjustment processing portion allows execution of the condition adjustment process to be restricted if the line speed mode is identical before and after a change of the printing type and a restriction condition is set in advance.

Abstract: An image forming apparatus includes an image forming portion, a first image processing portion, and a second image processing portion. The first image processing portion executes a plurality of types of image formation condition adjustment processes of the image forming portions on the image forming units used for monochrome printing in units of a specific number of condition adjustment processes in order whenever an execution history of the monochrome printing satisfies a monochrome adjustment condition set in advance. The plurality of types of condition adjustment processes is set in advance. The second image processing portion executes the plurality of types of condition adjustment processes on the image forming unit of the plurality of image forming units used for color printing in units of a specific number of condition adjustment processes in order whenever an execution history of the color printing satisfies a color adjustment condition set in advance.

Abstract: An image forming apparatus includes an image forming portion, a first image processing portion, and a second image processing portion. The second image processing portion, when a predetermined execution condition is satisfied, executes a detection image forming process in which a detection image that is used for adjusting an image forming condition in the image forming portion, is formed by the image forming portion in an area outside a print area on a transfer object. In a case where, after the detection image forming process is started during execution of a normal image forming process, the normal image forming process ends before the detection image forming process ends, the second image processing portion switches between continuing and not continuing the detection image forming process in accordance with a predetermined switch condition.

Abstract: A control device selects one of a plurality of chromatic colors as a target chromatic color according to a consumption status of developing agents of the plurality of chromatic colors. The control device causes an image forming portion to execute a process of forming, on a surface of a transfer medium, a plurality of chromatic color test images of the plurality of chromatic colors, and a superimposed test image in which a black test image is superimposed on a background image of the target chromatic color. The control device acquires a test detection signal of an amount of diffuse reflection light in each of areas of the plurality of chromatic color test images and the superimposed test image on the surface of the transfer medium. The control device adjusts timing of image formation of the plurality of colors by the image forming portion based on the test detection signal.

Abstract: A control portion causes an image forming portion to execute a test output process in which a plurality of test toner images each having a different developing voltage condition are formed in sequence on a surface of each of a plurality of image-carrying members and then transferred to an intermediate transfer body. The control portion sequentially selects, from the plurality of image-carrying members, target image-carrying members that are arranged at a distance greater than an arrangement spacing of the plurality of image-carrying members, and causes the image forming portion to execute the test output process so that each time one of the plurality of target image-carrying members is selected, the plurality of test toner images for each of the plurality of target image-carrying members are transferred within an area on the surface of the intermediate transfer body whose length corresponds to pacing between the plurality of target image-carrying members.

Abstract: An optical system used in an optical apparatus is configured to include a first lens group having positive refractive power, a focusing group that moves along an optical axis at focusing, and a rear group, in order from an object side, so that the first lens group includes a first-A lens group disposed on the object side of the largest air space A in the first lens group, and that all of the following conditional expressions are satisfied: 1.00<FNo×(TL/f)2<2.50 and 0.30<dA/dG1<0.85 where FNo is the f-number of the optical system focusing on infinity, TL is the total optical length of the optical system focusing on infinity, f is the focal length of the optical system focusing on infinity, dA is the length on the optical axis of the air space A, and dG1 is the length on the optical axis of the first lens group.

Abstract: An image forming apparatus includes a second acquisition processing portion and a third acquisition processing portion. The second acquisition processing portion acquires a first toner image forming condition of a toner image forming portion. The third acquisition processing portion acquires, based on the first toner image forming condition acquired by the second acquisition processing portion, a relational expression that indicates a relationship between a second toner image forming condition of the toner image forming portion and a toner concentration of a specific toner image that is formed by the toner image forming portion. Further, the third acquisition processing portion uses specific expressions that respectively correspond to a plurality of coefficients included in the relational expression to calculate the plurality of coefficients corresponding to the first toner image forming condition acquired by the second acquisition processing portion.

Abstract: An image forming apparatus includes an image forming portion, an exposure device, an image density sensor, and a control portion. The control portion can, by adjusting the development voltage based on the image density of a reference image and the amount of exposure from the exposure device, perform image density correction to adjust the image density. The control portion predicts the toner charge amount based on a formation condition of the reference image and the image density of the reference image and determines the timing of performing the image density correction next time based on the rate of change of the toner charge amount calculated using a first toner charge amount predicted when the image density correction was performed last time, a second toner charge amount predicted when the image density correction is performed this time, and the interval between the image density correction performed last time and this time.

Abstract: A control portion, by an image density sensor detecting density of reference images for image density correction formed by a plurality of image forming portions, adjusts a developing voltage and an exposure amount of an exposure device based on the detection result. The control portion, based on the density of the reference images detected by the image density sensor, sets a common developing voltage such that the densities of the reference images are equal to or higher than a target density in all of the two or more image forming portions among the plurality of image forming portions. The control portion, by adjusting a toner adhesion area ratio for image forming portions of the two or more image forming portions in which the densities of the reference images exceed the target density when a common developing voltage is set, adjusts the densities of the reference images to the target density.

Abstract: An optical system used in an optical apparatus is configured to include a first lens group having positive refractive power, a focusing group that moves along an optical axis at focusing, and a rear group, in order from an object side, so that the first lens group includes a first-A lens group disposed on the object side of the largest air space A in the first lens group, and that all of the following conditional expressions are satisfied: 1.00<FNo×(TL/f)2<2.50 and 0.30<dA/dG1<0.85 where FNo is the f-number of the optical system focusing on infinity, TL is the total optical length of the optical system focusing on infinity, f is the focal length of the optical system focusing on infinity, dA is the length on the optical axis of the air space A, and dG1 is the length on the optical axis of the first lens group.

Abstract: The mode setting unit sets the mode of the display unit to a blind mode. An operation for the mode setting unit to set the mode of the display unit to the blind mode is input to the input unit. The image changing unit changes the mode of the display unit from the normal mode to the blind mode based on the operation input to the input unit, and changes at least one of the color and density of the display image of the display unit according to the blind mode. When an operation for setting the mode of the display unit to the blind mode is input to the input unit, the display unit displays a preview image obtained by changing the image data before the image forming unit forms on the sheet in accordance with the blind mode as the display image of the display screen.

Abstract: A belt member includes: a strip member having an elongate shape; a fastener disposed along the longitudinal direction of the strip member; and an opening-closing device that opens or closes the fastener. For reducing a contact pressure of the belt member per unit area, the fastener is opened by the opening-closing device to unfold the belt member into a form of a wide strip so that the width of the belt member is increased. On the other hand, when the fastener is closed by the opening-closing device, the belt member takes a form of a narrow tube so that the width of the belt member is reduced.

Abstract: A belt member includes: a strip member having an elongate shape; a fastener disposed along the longitudinal direction of the strip member; and an opening-closing device that opens or closes the fastener. For reducing a contact pressure of the belt member per unit area, the fastener is opened by the opening-closing device to unfold the belt member into a form of a wide strip so that the width of the belt member is increased. On the other hand, when the fastener is closed by the opening-closing device, the belt member takes a form of a narrow tube so that the width of the belt member is reduced.

Abstract: A database system which quickly creates a snapshot copy of the backup files. The system has a plurality of database storage subsystems which are normally operating as a mirrored storage system under the control of a mirroring controller. A write suspending unit temporarily suspends write operations to those storage subsystems, and a device detachment unit detaches at least one of the database storage subsystems from the mirrored storage system. A write restarting unit then allows write operations to the remaining database storage subsystems. A correction processor makes corrections to the detached database storage subsystem to resolve any inconsistency in its records, which might have been introduced in relation with such transactions that were in process at the time of the detachment. A data converter converts file location data for the detached database storage subsystem, so that it will serve as a separate database volume.