Abstract: An image forming apparatus includes a rotatable image carrier that carries a toner image having a length corresponding to at least a circumferential length of the carrier; an image density detector that detects a density of the image; a potential detector that detects, over at least the circumferential length, a surface potential of the carrier before toner adheres thereto; a first image forming device that adjusts the density with a first factor, and forms an image based on a first condition of the first factor; a second image forming device that adjusts the density with a second factor, and forms an image based on a second condition of the second factor; a first determining device that determines the first condition based on uneven density; and a second determining device that determines the second condition based on uneven density and a potential distribution of the surface potential.

Abstract: A sheet conveying apparatus includes a sheet conveying unit including a drive roller and a driven roller; a downstream detection unit and an upstream detection unit; a conveying amount measuring unit that measures a conveying amount of the sheet; and a conveying distance calculation unit that calculates a conveying distance of the sheet, wherein a distance between the downstream detection unit and the upstream detection unit or a perimeter of one of the drive roller and the driven roller is set such that an expected conveying distance calculated based on a set sheet length of an expected value of the sheet becomes a substantially integer multiple of a perimeter of the one of the drive roller and the driven roller.

Abstract: A disclosed sheet carrying device includes a first carrying unit that includes a first rotary body, a first driving unit outputting a driving force at a first peripheral speed, a one-way clutch transmitting the driving force only in a sheet carrying direction, and a second rotary body driven by the first rotary body via the sheet; and a second carrying unit including a third rotary body rotating at a second peripheral speed being the first peripheral speed or more, a fourth rotary body carrying the sheet with the third rotary body, a second driving unit outputting a driving force for driving the fourth rotary body at a third peripheral speed being the second peripheral speed or more, and a torque limiter having a slip torque smaller than a sheet carrying torque and cutting off the driving force while the sheet is interposed between the third and fourth rotary bodies.

Abstract: A sheet conveying apparatus includes a sheet conveying unit that conveys a sheet including a drive roller, a driven roller, and a rotary encoder provided on a rotational axle of one of the drive roller and the driven roller; a conveying amount measuring unit that measures a conveying amount of the sheet; a first detection unit positioned downstream of the sheet conveying unit, the first detection unit being positioned apart from the drive roller and the driven roller not to overlap with the drive roller and the driven roller in the conveying direction; a second detection unit positioned upstream of the sheet conveying unit; and a conveying distance calculation unit that calculates a conveying distance of the sheet based on the measured result by the conveying amount measuring unit and the detected results detected by the first detection unit and the second detection unit.

Abstract: An image forming apparatus includes an image carrier; an image forming unit; a processor for controlling the image forming unit according to a predetermined image forming condition setting data; an image density sensor to detect an image density of the toner pattern formed on the image carrier; a reference rotary position detector; an image density fluctuation data acquisition unit to obtain an image density fluctuation data of more than one circumferential length of the photoreceptor drum with reference to the reference rotary position detected by the reference rotary position detector based on a result related to the toner pattern formed on the image carrier detected by the image density sensor; and a correction data generator to generate a correction data to correct a reference image forming condition setting data with a correction amount corresponding to each rotary position of the rotary member to thus reduce the image density fluctuation.

Abstract: An objective is to achieve a positional change measurement device which measures positional change of a dynamic measured surface by using speckle patterns while easily reducing influence of fluctuations in a measurement environment temperature. Provided is a positional change measurement device including: a light source; an illuminating optical system configured to guide light from the light source to a measured surface; an imaging optical system; an image pickup device configured to acquire a speckle pattern by receiving reflection light from the measured surface via the imaging optical system; and detected-length compensation means for compensating for fluctuations in a detected length caused by temperature fluctuations. Positional change of the measured surface is measured based on a result of cross-correlation computation performed on multiple speckle patterns acquired at predetermined time intervals.

Abstract: A bookbinding system includes an image forming unit to form a toner image on a sheet; a fixing device to fix the toner image onto the sheet; a sheet stacker to load sheets passing through the fixing device, to create a sheet bundle, in which the sheet bundle stacked on the sheet stacker is adhered to produce a complete book; an adhesive toner image forming unit to form an adhesive toner image on an area corresponding to a spine of the complete book; and a heater to heat the unfixed adhesive toner image formed on each sheet of the sheet bundle stacked on the sheet stacker, wherein the adhesive toner image on the sheet stacked on the sheet stacker is the unfixed toner image.

Abstract: A sheet conveying apparatus includes a sheet conveying unit that conveys a sheet; a conveying amount measuring unit that measures a conveying amount of the sheet conveyed by the sheet conveying unit; a first detection unit that detects the sheet downstream of the sheet conveying unit in a conveying direction of the sheet; a second detection unit that detects the sheet upstream of the sheet conveying unit in the conveying direction of the sheet; and a conveying distance calculation unit that calculates a conveying distance of the sheet based on the measured result by the conveying amount measuring unit and the detected results detected by the first detection unit and the second detection unit.

Abstract: An image forming apparatus includes an image carrier; a developing device; a transfer device; and a fixing device. An electrostatic latent image formed on the image carrier is rendered visible as a toner image by depositing the toner by the developing device, and the toner image is transferred by the transfer device and fixed onto a recording medium by the fixing device and output. The apparatus further includes a density fluctuation meter including a rotary position detector, a density fluctuation detector, and a density fluctuation storage; a density fluctuation extractor unit including a first extractor, a second extractor, and a density fluctuation storage; and a control table generator unit including a control table generator and a control table storage, so that based on the control table stored in the control table storage, the voltage to be applied to the developing device is controlled and the toner image is output.

Abstract: A binding apparatus includes: an accumulating unit where a plurality of sheets having an area that serves as a binding margin is to be stacked as a sheet bundle, in which toner is fixed onto all of, or a part of, the area; a pressure unit that sandwiches the binding margin of the sheet bundle stacked on the accumulating unit therebetween and applies a pressure to the binding margin; and a heating unit that heats the toner on the binding margin that is receiving the pressure applied by the pressure unit. The pressure unit is configured to apply the pressure to the binding margin while forming a plurality of grooves and ridges in the binding margin in a direction in which the pressure is applied.

Abstract: A sheet length measuring device includes a rotating body configured to rotate with a movement of a sheet in a conveying direction; a position detecting unit configured to detect leading and trailing ends of the sheet passing through a position of the rotating body; a measuring unit configured to measure a rotation amount of the rotating body and output an origin signal per one revolution of the rotating body; a storage unit configured to store changes of a sheet conveying amount with respect to respective rotation angles in one revolution of the rotating body; and a calculating unit configured to calculate a corrected length of the sheet from a value obtained from a rotation angle of the rotating body when the leading end of the sheet is detected and a value obtained from a rotation angle of the rotating body when the trailing end of the sheet is detected.

Abstract: A sheet post-processing apparatus includes: a binding unit that binds, as a bundle, a plurality of sheets by heating and pressing binding margin portions of the sheets set in advance, using toner interposed between the sheets as an adhesive material; and a pre-heating unit that heats the binding margin portions of the sheets while the sheets are stacked.

Abstract: A moving-member detecting device includes an image acquiring unit and a speed calculating unit. The image acquiring unit includes a light source configured to emit a light beam to a detecting position of a moving member; an area sensor configured to acquire image data of a one- or two-dimensional image; and an area-sensor control unit configured to acquire the image data. The image acquiring unit is configured to acquire pieces of image data of the moving member at first and second positions, respectively, in a moving direction of the moving member so as to acquire the piece of position image data for the second position when the moving member is at the second position after acquiring the piece of image data for the first position. The speed calculating unit is configured to calculate a moving speed of the moving member from the pieces of image data.

Abstract: An image forming apparatus includes an image forming unit forming an image on a first recording medium based on image data, a measurement unit being positioned in an immediate vicinity of the image forming unit, being arranged upstream of a sheet-conveyance path than the image forming unit, and measuring a size of the first recording medium, an expansion ratio calculation unit calculating an expansion ratio of the first recording medium based on a first size of the first recording medium obtained before the first recording medium is passed through the image forming unit and a second size of the first recording medium obtained after the first recording medium is passed through the image forming unit, and a correction unit correcting the image data used for forming another image on a second recording medium conveyed after the first recording medium based on the expansion ratio.

Abstract: An image forming apparatus includes an image forming unit that forms an image on a recording medium; a width detector that detects positions of side edges of the recording medium in a width direction, which is orthogonal to a conveying direction in which the recording medium is conveyed, at multiple detection positions along the conveying direction; a shape calculator that calculates angles between the conveying direction and straight lines each connecting the positions of the same side edge detected at the multiple detection positions and calculates a shape of the recording medium based on the angles; and a correction unit that corrects image data of the image to be formed by the image forming unit based on the calculated shape of the recording medium.

Abstract: A disclosed to-be-transferred object length measurement device includes a first rotating body; a passage detection unit detecting a passage of the to-be-transferred object; a rotation amount measurement unit measuring a rotation amount of the first rotating body in a first measurement period; a second rotating body feeding the to-be-transferred object; a speed detection unit detecting a first feeding speed and a second feeding speed of the to-be-transferred object; and a calculation unit calculating a feeding distance of the to-be-transferred object per a predetermined rotation amount of the first rotating body based on the first feeding speed, and further calculating a length of the to-be-transferred object based on the rotation amount of the first rotating body in the first measurement period, the feeding distance, and the second feeding speed of the to-be-transferred object in the second measurement period.

Abstract: A sheet conveying apparatus including: a sheet conveying unit; an upstream side guiding member that forms an upstream side conveying route of a sheet; a downstream side guiding member that forms a downstream side conveying route of the sheet; an upstream side detection unit; and a downstream side detection unit, wherein a detection position of the sheet for the upstream side detection unit is set between the sheet conveying unit and a position where the sheet is in contact with the upstream side guiding member, and a detection position of the sheet for the downstream side detection unit is set between the sheet conveying unit and a position where the sheet is in contact with the downstream side guiding member.

Abstract: An image forming apparatus includes a drive roller configured to rotate, a driven roller configured to hold and convey a print medium at a gap between the drive and driven rollers, an image carrier configured to have a toner image formed on a surface thereof and to rotate, the image carrier being situated downstream relative to the drive roller and the driven roller in a travel direction of the print medium, a transfer roller configured to hold and convey, at another gap between the image carrier and the transfer roller, the print medium passed from the drive roller and the driven roller to transfer the toner image onto a surface of the print medium, and a conveyance suspension unit to stop the drive roller and the driven roller from applying a drive force to the print medium at a time at which the print medium reaches such another gap.

Abstract: An image forming apparatus includes a rotatable image carrier that carries a toner image having a length corresponding to at least a circumferential length of the carrier; an image density detector that detects a density of the image; a potential detector that detects, over at least the circumferential length, a surface potential of the carrier before toner adheres thereto; a first image forming device that adjusts the density with a first factor, and forms an image based on a first condition of the first factor; a second image forming device that adjusts the density with a second factor, and forms an image based on a second condition of the second factor; a first determining device that determines the first condition based on uneven density; and a second determining device that determines the second condition based on uneven density and a potential distribution of the surface potential.

Abstract: An image forming apparatus includes an image carrier; a developer carrier configured to adhere toner onto the image carrier; an image density detector to detect a density of an image on the image carrier formed by the developer carrier adhering the toner on the image carrier; a rotary member to form an image pattern of which density is detected by the image density detector; and a rotational position detector to detect a rotational position of the rotary member. In the image forming apparatus, the image pattern is generated based on the rotational position detected by the rotational position detector and the rotary member that the rotational position detector detects the rotational position thereof is either the image carrier or the developer carrier.