Abstract: In the image forming apparatus, a color shift correction execution check unit detects positions of density correction patches of respective colors according to binary signals of density detection outputs by a density sensor on the density correction patches. When distances corresponding to intervals of time from starts of image drawing of the density correction patches of the respective colors to the detection of the positions of the density correction patches of the respective colors and distances between the density correction patches of the respective colors are shifted from a value, the color shift correction execution check unit determines color shift correction processing is required to be executed, and it gives an instruction to a color shift correction control unit to execute the color shift correction processing. And the color shift correction control unit forms a color shift correction patch to execute the color shift correction processing.

Abstract: A prediction table is stored in an NVM and an in-apparatus temperature is measured by a temperature sensor, a registration control adjustment based on the prediction table is carried out if an absolute value of a variation in the in-apparatus temperature is smaller than a threshold, and a registration adjusting patch is formed to actually measure a positional shift amount if the absolute value of the variation in the in-apparatus temperature is equal to or greater than the threshold. When the positional shift amount measured actually is greatly different from a value of the prediction table, the value of the prediction table is modified into the actually measured value.

Abstract: An image forming apparatus includes: a plurality of paper supplying trays; an image forming unit; and a cover. The image forming apparatus further includes a cover opening/closing detecting unit that detects an operation for opening/closing the cover; a paper supplying tray opening/closing detecting unit that detects an operation for opening/closing the paper supplying tray; a paper jam detecting unit that detects a paper jam in at least one place in a paper transporting path; a paper jam release deciding unit that decides whether the paper jam in the detecting place is released or not after the confirmation of a detection; and a completion control unit that controls to complete a paper jam processing based on the decision that the paper jam in all of the places in the paper transporting path is released through the paper jam release deciding unit.

Abstract: An image forming apparatus includes image forming sections that forms images of different colors, respectively, a correction image formation controlling section that forms correction images of the respective colors, a density sensor that detects a density of each of the correction images in synchronization with passage of each correction image on an image carrying body, a detecting section that detects a position and the density of each of the correction images, based on a binary signal of a density detection output of each of the correction images, a density correction controlling section that corrects and controls an image density of the color, based on the detected density of each of the correction images, and a color deviation correction controlling section that corrects and controls the color deviation, based on the detected position of each of the correction images.

Abstract: An image forming apparatus includes a plurality of image forming units that form toner images in different color; an image carrier which carries the toner image of each color; a determination unit that determines, in relation to a size of image data instructed to print, whether or not a first area where a misregistration correcting image is formed at an end portion in a width direction of the image carrier is secured; a first control unit that controls the image forming unit; and a detection sensor that detects the misregistration correcting image formed on the image carrier by controlling of the first control unit; wherein the misregistration of the toner image formed by each image forming unit is corrected on a basis of a value detected by the detection sensor.

Abstract: An image forming apparatus includes: a plurality of paper supplying trays; an image forming unit; and a cover. The image forming apparatus further includes a cover opening/closing detecting unit that detects an operation for opening/closing the cover; a paper supplying tray opening/closing detecting unit that detects an operation for opening/closing the paper supplying tray; a paper jam detecting unit that detects a paper jam in at least one place in a paper transporting path; a paper jam release deciding unit that decides whether the paper jam in the detecting place is released or not after the confirmation of a detection; and a completion control unit that controls to complete a paper jam processing based on the decision that the paper jam in all of the places in the paper transporting path is released through the paper jam release deciding unit.

Abstract: An image forming apparatus includes: a plurality of image forming units as defined herein; an image carrier as defined herein; a first operation controlling unit as defined herein; a second operation controlling unit as defined herein; a density detecting sensor that detects densities of the images formed on the image carrier; a measuring unit that binarizes a density detection output of the image position deviation correction patterns formed on the image carrier, from the density detecting sensor, and that measures intervals between color patterns of the image position deviation correction patterns, based on the binarized output; and a position deviation correction controlling unit that performs a position deviation correcting control of, when the intervals measured by the measuring unit and of the color patterns in the image position deviation correction patterns are deviated from a predetermined range, correcting position deviation of the toner images formed by the image forming units.

Abstract: A prediction table is stored in an NVM and an in-apparatus temperature is measured by a temperature sensor, a registration control adjustment based on the prediction table is carried out if an absolute value of a variation in the in-apparatus temperature is smaller than a threshold, and a registration adjusting patch is formed to actually measure a positional shift amount if the absolute value of the variation in the in-apparatus temperature is equal to or greater than the threshold. When the positional shift amount measured actually is greatly different from a value of the prediction table, the value of the prediction table is modified into the actually measured value.

Abstract: An image forming apparatus includes image forming sections that forms images of different colors, respectively, a correction image formation controlling section that forms correction images of the respective colors, a density sensor that detects a density of each of the correction images in synchronization with passage of each correction image on an image carrying body, a detecting section that detects a position and the density of each of the correction images, based on a binary signal of a density detection output of each of the correction images, a density correction controlling section that corrects and controls an image density of the color, based on the detected density of each of the correction images, and a color deviation correction controlling section that corrects and controls the color deviation, based on the detected position of each of the correction images.

Abstract: In the image forming apparatus, a color shift correction execution check unit detects positions of density correction patches of respective colors according to binary signals of density detection outputs by a density sensor on the density correction patches. When distances corresponding to intervals of time from starts of image drawing of the density correction patches of the respective colors to the detection of the positions of the density correction patches of the respective colors and distances between the density correction patches of the respective colors are shifted from a value, the color shift correction execution check unit determines color shift correction processing is required to be executed, and it gives an instruction to a color shift correction control unit to execute the color shift correction processing. And the color shift correction control unit forms a color shift correction patch to execute the color shift correction processing.

Abstract: An image forming apparatus includes: a plurality of image forming units as defined herein; an image carrier as defined herein; a first operation controlling unit as defined herein; a second operation controlling unit as defined herein; a density detecting sensor that detects densities of the images formed on the image carrier; a measuring unit that binarizes a density detection output of the image position deviation correction patterns formed on the image carrier, from the density detecting sensor, and that measures intervals between color patterns of the image position deviation correction patterns, based on the binarized output; and a position deviation correction controlling unit that performs a position deviation correcting control of, when the intervals measured by the measuring unit and of the color patterns in the image position deviation correction patterns are deviated from a predetermined range, correcting position deviation of the toner images formed by the image forming units.

Abstract: An image forming apparatus includes a plurality of image forming units that form toner images in different color; an image carrier which carries the toner image of each color; a determination unit that determines, in relation to a size of image data instructed to print, whether or not a first area where a misregistration correcting image is formed at an end portion in a width direction of the image carrier is secured; a first control unit that controls the image forming unit; and a detection sensor that detects the misregistration correcting image formed on the image carrier by controlling of the first control unit; wherein the misregistration of the toner image formed by each image forming unit is corrected on a basis of a value detected by the detection sensor.