Abstract: In a reuse method for reusing a reusable device and a sensor of a first image forming apparatus having a first process linear velocity in a second image forming apparatus having at least one second process linear velocity different from the first process linear velocity, the reusable device and the sensor are installed in the first image forming apparatus, and when the first image forming apparatus switches from the first process linear velocity to the second process linear velocity at an initial state before the reusable device is used, output of the sensor at the second process linear velocity is measured. When information on the output of the sensor at the second process linear velocity is stored, the reusable device and the sensor are removed from the first image forming apparatus and installed in the second image forming apparatus.

Abstract: A time point at which a predetermined period elapses since the start of use of a copying machine as a detection subject after factory shipment or repair is obtained. Pieces of set information, which are combinations of various types of information until the time point is reached are sequentially stored to construct a normal set information group. After the time point is reached, presence of abnormality in the copying machine is determined based on the normal set information group and the various types of information obtained.

Abstract: An optical sensor includes a light-emitting element for directing light to an image, a light-receiving element for receiving light reflected by the image, a normal detection optical path for allowing the light emitted by the light-emitting element and the light reflected from the image to follow a normal detection optical path during normal operation, a calibration reflecting plate disposed inside the optical sensor for reflecting light from the light-emitting element when sensitivity is calibrated, a calibration optical path for allowing the light emitted by the light-emitting element to follow a calibration optical path to the light-receiving element when the emitted light is reflected by the calibration reflecting plate, and a first optical function element disposed in the calibration optical path and switchable between a light permeating state, in which the light passes therethrough, and a light intercepting state, in which the light is blocked, when voltage is applied.

Abstract: An image-information acquiring unit acquires the image information divided at least in one of a main-scanning direction and a sub-scanning direction. A supply control unit calculates basic-supply patterns of a supply amount of toner and controls the supply amount at a supply point in a developing unit using a toner supply pattern combined with the basic-supply patterns that eliminate temporal variation in toner density of the developer, at the specific point, due to development of the latent image.

Abstract: A method of arranging a plurality of image forming sections, each of which includes a developing device and a cleaning device. The method includes arranging the plurality of image forming sections side by side along an inclined image carrier; and positioning the cleaning device above the developing device of other image forming sections in one of nearby ones of the plurality of image forming sections.

Abstract: An image forming apparatus includes an image forming unit, an image sensor unit, an image data obtaining unit, and an image quality determiner unit to determine quality of an image on a print sheet after fusing based on input image data and output image data as a result of detection by the image sensor unit. According to a result of the determination, a print sheet containing an image determined as a non-normal image is discharged to a first paper tray while that containing an image determined as a normal image is discharged to a second paper tray.

Abstract: An image forming apparatus forms a plurality of tone patterns of different colors, each of which containing a plurality of toner patches having different toner densities. Some of the toner patches in each of the tone patterns are formed with a predetermined fixed developing bias and the rest of the toner patches in each of the tone patterns are formed with developing biases set based on previous developing biases that have been obtained through a previous control process. The largest toner density of the toner patches in each of the tone patterns is determined based on a magnitude relation of previous index values obtained through the previous control process.

Abstract: In a reuse method for reusing a reusable device and a sensor of a first image forming apparatus having a first process linear velocity in a second image forming apparatus having at least one second process linear velocity different from the first process linear velocity, the reusable device and the sensor are installed in the first image forming apparatus, and when the first image forming apparatus switches from the first process linear velocity to the second process linear velocity at an initial state before the reusable device is used, output of the sensor at the second process linear velocity is measured. When information on the output of the sensor at the second process linear velocity is stored, the reusable device and the sensor are removed from the first image forming apparatus and installed in the second image forming apparatus.

Abstract: An image forming apparatus is provided which is of an electrophotographic type, and is capable of setting a gradation number of a patch pattern to be formed corresponding to various factor information, and to perform a process control. The image forming apparatus includes a patch pattern forming part to form a toner image of a patch pattern on an image carrier; a developing part to develop the patch pattern; a toner image density detecting part to measure a toner image density of the patch pattern; and a process control performing part to vary an image forming process condition based on detection results obtained from the toner image density detecting part, and to stabilize an image density.

Abstract: In a state deciding apparatus, an information acquiring unit acquires pieces of information of different types related to a state of an image forming apparatus. An index value calculating unit calculates an index value based on the pieces of information acquired. A state change deciding unit decides a change in a subsequent state of the image forming apparatus, based on a temporal change in the index value calculated.

Abstract: An image forming apparatus and an image density control method for controlling image density in the image forming apparatus, involving adjusting a toner concentration control reference value in accordance with an amount of the toner replaced in a developing device so as to adjust the image density to maintain a consistent developability and changing image forming intervals in accordance with an amount of the toner replaced in the developing device during continuous printing operation.

Abstract: A time point at which a predetermined period elapses since the start of use of a copying machine as a detection subject after factory shipment or repair is obtained. Pieces of set information, which are combinations of various types of information until the time point is reached are sequentially stored to construct a normal set information group. After the time point is reached, presence of abnormality in the copying machine is determined based on the normal set information group and the various types of information obtained.

Abstract: An optical sensor includes a light-emitting element for directing light to an image, a light-receiving element for receiving light reflected by the image, a normal detection optical path for allowing the light emitted by the light-emitting element and the light reflected from the image to follow a normal detection optical path during normal operation, a calibration reflecting plate disposed inside the optical sensor for reflecting light from the light-emitting element when sensitivity is calibrated, a calibration optical path for allowing the light emitted by the light-emitting element to follow a calibration optical path to the light-receiving element when the emitted light is reflected by the calibration reflecting plate, and a first optical function element disposed in the calibration optical path and switchable between a light permeating state, in which the light passes therethrough, and a light intercepting state, in which the light is blocked, when voltage is applied.

Abstract: A time point at which a predetermined period elapses since the start of use of a copying machine as a detection subject after factory shipment or repair is obtained. Pieces of set information, which are combinations of various types of information until the time point is reached are sequentially stored to construct a normal set information group. After the time point is reached, presence of abnormality in the copying machine is determined based on the normal set information group and the various types of information obtained.

Abstract: An image forming apparatus includes an image forming unit configured to form a plurality of toner images on an image carrier, an optical detector configured to detect reflection light from the toner image, and dedicated to detect infrared rays and near-infrared rays, and a controller configured to perform a predetermined control using a detection results of the optical detector. Gradation pattern that is comprised of a plurality of toner patches formed in the image forming unit with an image forming condition to have different adhesive amounts, and is formed of at least two colors, and detection values detected by the optical detector are used for the predetermined control.

Abstract: A method of arranging a plurality of image forming sections, each of which includes a developing device and a cleaning device. The method includes arranging the plurality of image forming sections side by side along an inclined image carrier; and positioning the cleaning device above the developing device of other image forming sections in one of nearby ones of the plurality of image forming sections.

Abstract: An image forming apparatus includes an image carrier configured to carry an electrostatic latent image, a developing device configured to develop the electrostatic latent image with a two-component developer including toner and magnetic carrier, a toner supplier configured to supply the toner to the developing device, a toner concentration detector configured to detect toner concentration in the two-component developer inside the developing device, and a controller. The controller is configured to detect first information to determine toner replacement amount in the developing device during a predetermined time period and second information to determine a charge characteristic of the toner in the developing device, change a toner concentration control reference value based on the first information and the second information, and control the toner concentration based on an output from the toner concentration detector and the toner concentration control reference value.

Abstract: A developing device of the present invention is operable with a two-ingredient type developer by mixing and agitating toner grains and carrier grains to thereby electrify the toner grains. At least the carrier grains are sealed in a space formed in the developing device until the developing device starts being used while the toner grains are introduced in the developing device at the start of use.

Abstract: An image forming apparatus includes an acquiring unit that acquires a plurality of types of operation control information of the image forming apparatus; an index value calculating unit that calculates an index value indicating a state of the image forming apparatus based on the acquired operation control information; an abnormality judging unit that judges whether the image forming apparatus abnormality has occurred and predicts an occurrence of a failure based on the index value; and a detection pattern position detecting unit that detects a position of a detection pattern on an image carrier carrying a toner image. The detection pattern is formed on the image carrier carrying the toner image. The detection pattern position detecting unit detects the position of the detection pattern formed on the image carrier. The index value calculating unit uses information based on position detection data as the operation control information of the image forming apparatus.

Abstract: A tandem image forming device for an image forming apparatus of the present invention includes a plurality of image forming means arranged side by side along an intermediate image transfer belt. The image forming means each include a developing device and a cleaning device arranged around an image carrier. One of nearby image forming means has its cleaning device positioned above the developing device of the other image forming means, e.g., an agitating section forming part of the image forming means. This configuration insures smooth circulation of a developer and therefore obviates an irregular developer distribution while reducing the overall size of the image forming device.