Abstract: A liquid discharge head includes nozzles, pressure chambers, a common supply channel, a common collection channel, and an air chamber. The nozzles are configured to discharge liquid. The pressure chambers are communicated with the nozzles, respectively. The common supply channel is communicated with the pressure chambers. The common supply channel includes a displaceable first region in a part of a wall of the common supply channel. The common collection channel is communicated with the pressure chambers. The common collection channel includes a displaceable second region in a part of a wall of the common collection channel. The air chamber faces a surface of the first region and a surface of the second region. The surface of the first region is opposite the wall of the common supply channel. The surface of the second region is opposite the wall of the common collection channel.

Abstract: A liquid discharge head includes nozzles, pressure chambers, a common supply channel, a common collection channel, and an air chamber. The nozzles are configured to discharge liquid. The pressure chambers are communicated with the nozzles, respectively. The common supply channel is communicated with the pressure chambers. The common supply channel includes a displaceable first region in a part of a wall of the common supply channel. The common collection channel is communicated with the pressure chambers. The common collection channel includes a displaceable second region in a part of a wall of the common collection channel. The air chamber faces a surface of the first region and a surface of the second region. The surface of the first region is opposite the wall of the common supply channel. The surface of the second region is opposite the wall of the common collection channel.

Abstract: A position measurement reference sheet for image position measurement on a recording medium includes a body having a front face to face an image reading face of a reading device, a recording medium detection window in the body to measure a position of an end of the recording medium, and an image detection window in the body to measure a position of an image on the recording medium. The position measurement reference sheet is interposed between the image reading face and the recording medium.

Abstract: An image inspection apparatus for inspecting an output image on a recording medium by scanning the output image as a scanned image includes an inspection reference image generator to generate an inspection reference image using data of an output-target image; an image inspection unit to determine whether the scanned image includes a defect by comparing a difference between the inspection reference image and the scanned image with a given threshold; and a threshold determiner to determine the given threshold. The threshold determiner computes a difference between the inspection reference image and the scanned image. The threshold determiner determines the given threshold based on the difference between the scanned image and the inspection reference image.

Abstract: An image inspection apparatus for inspecting an output image on a recording medium by scanning the output image as a scanned image includes an inspection reference image generator to generate an inspection reference image using data of an output-target image; an image inspection unit to determine whether the scanned image includes a defect by comparing a difference between the inspection reference image and the scanned image with a given threshold; and a threshold determiner to determine the given threshold. The threshold determiner computes a difference between the inspection reference image and the scanned image. The threshold determiner determines the given threshold based on the difference between the scanned image and the inspection reference image.

Abstract: A position measurement reference sheet for image position measurement on a recording medium includes a body having a front face to face an image reading face of a reading device, a recording medium detection window in the body to measure a position of an end of the recording medium, and an image detection window in the body to measure a position of an image on the recording medium. The position measurement reference sheet is interposed between the image reading face and the recording medium.

Abstract: An image inspection apparatus for inspecting an output image on a recording medium by scanning the output image as a scanned image includes an inspection reference image generator to generate an inspection reference image using data of an output-target image; an image inspection unit to determine whether the scanned image includes a defect by comparing a difference between the inspection reference image and the scanned image with a given threshold; and a threshold determiner to determine the given threshold. The threshold determiner computes a difference between the inspection reference image and the scanned image. The threshold determiner determines the given threshold based on the difference between the scanned image and the inspection reference image.

Abstract: An image forming system includes an image forming unit configured to output image data onto a recording medium; a first conveying unit configured to convey the medium; a reading unit configured to read an image from the medium; a defect determining unit configured to determine whether the read image has a defect; a device connection determining unit configured to determine whether a discharge device is directly connected to an image inspection device at the downstream side or is connected to the image inspection device via another device at the downstream side; a second conveying unit configured to convey the medium to the discharge device on a longer conveying path, when the discharge device is directly connected to the image inspection device; a defective discharge tray to which the medium having a defective image is discharged; and a normal discharge tray to which the medium having a non-defective image is discharged.

Abstract: An image inspection apparatus for inspecting an output image on a recording medium by scanning the output image as a scanned image includes an inspection reference image generator to generate an inspection reference image using data of an output-target image; an image inspection unit to determine whether the scanned image includes a defect by comparing a difference between the inspection reference image and the scanned image with a given threshold; and a threshold determiner to determine the given threshold. The threshold determiner computes a difference between the inspection reference image and the scanned image. The threshold determiner determines the given threshold based on the difference between the scanned image and the inspection reference image.

Abstract: According to one embodiment, transit time taken for a recording medium passing through a nip portion to transit a predetermined distance is measured. A nip width adjusting mechanism adjusts a nip width on the basis of the transit time of the recording medium over the predetermined distance.

Abstract: An image forming system includes an image forming unit configured to output image data onto a recording medium; a first conveying unit configured to convey the medium; a reading unit configured to read an image from the medium; a defect determining unit configured to determine whether the read image has a defect; a device connection determining unit configured to determine whether a discharge device is directly connected to an image inspection device at the downstream side or is connected to the image inspection device via another device at the downstream side; a second conveying unit configured to convey the medium to the discharge device on a longer conveying path, when the discharge device is directly connected to the image inspection device; a defective discharge tray to which the medium having a defective image is discharged; and a normal discharge tray to which the medium having a non-defective image is discharged.

Abstract: An image forming apparatus is disclosed that includes an image carrier, a driving source, a rotation detection unit, and a control unit that performs fluctuation pattern recognition processing, control pattern construction processing, speed fine-adjustment processing, and remaining pattern recognition processing. The control unit is configured to perform control pattern correction processing for setting a frequency band of a remaining speed fluctuation to be detected by the remaining pattern recognition processing narrower than a frequency band of a speed fluctuation to be detected by the fluctuation pattern recognition processing and correcting the speed control pattern so as to be a pattern capable of reducing even the remaining speed fluctuation based on a remaining speed fluctuation pattern recognized by the remaining pattern recognition processing.

Abstract: An image forming apparatus includes: a sheet conveyance path in which a sheet is conveyed; at least one sheet feeding mechanism to supply the sheet to the sheet conveyance path; a sheet conveyance mechanism to convey the sheet in a sheet conveyance direction; a detection mechanism to detect a position of a side of the sheet parallel to the sheet conveyance direction; a movement mechanism to move the sheet in a direction perpendicular to the sheet conveyance direction; a memory to store reference position information specific to the at least one sheet feeding mechanism, respectively; and a movement control mechanism to control a movement distance of the movement mechanism based on the detected position and the reference position information specific to a selected one of the at least one sheet feeding mechanism.

Abstract: A fixing device includes a fixing roller that is driven to rotate, a fixing belt that is driven by rotation of the fixing roller, and a driven roller that rotates along with the fixing belt. The fixing device also includes a pressing member that is pressed against the fixing roller with the fixing belt interposed therebetween to form a nip portion, a measuring unit that measures a rotation speed of the driven roller, and a control unit that adjusts a fixing condition based on the rotation speed of the driven roller.

Abstract: A belt driving control device that includes a belt, a driving roller transmitting drive force to the belt, a belt phase detecting section detecting a phase of the belt, a correction amount computing section computing a correction amount of a belt travelling velocity corresponding to the detected phase of the belt for cancelling out fluctuation in the belt travelling velocity corresponding to the detected phase of the belt, and a storage section storing the correction amount of the belt travelling velocity corresponding to the detected phase of the belt. The belt driving control device further includes a driving control section retrieving the correction amount of the belt travelling velocity corresponding to the phase of the belt and controlling drive of the driving roller to cancel out the fluctuation in the belt travelling velocity based on the retrieved correction amount of the belt travelling velocity corresponding to the detected phase of the belt.

Abstract: A control unit calculates a difference between a displacement of a belt detected by an encoder and a predetermined target value, calculates a pulse frequency of a driving pulse signal based on a feedback control based on the difference and a feed-forward control based on a reference driving pulse frequency, sets a control range of the feedback control to be equal to or smaller than a frequency of one rotation of a driven roller, and controls driving of a pulse motor such that the belt moves at a constant speed.

Abstract: According to one embodiment, transit time taken for a recording medium passing through a nip portion to transit a predetermined distance is measured. A nip width adjusting mechanism adjusts a nip width on the basis of the transit time of the recording medium over the predetermined distance.

Abstract: A belt driving control device that includes a belt, a driving roller transmitting drive force to the belt, a belt phase detecting section detecting a phase of the belt, a correction amount computing section computing a correction amount of a belt travelling velocity corresponding to the detected phase of the belt for cancelling out fluctuation in the belt travelling velocity corresponding to the detected phase of the belt, and a storage section storing the correction amount of the belt travelling velocity corresponding to the detected phase of the belt. The belt driving control device further includes a driving control section retrieving the correction amount of the belt travelling velocity corresponding to the phase of the belt and controlling drive of the driving roller to cancel out the fluctuation in the belt travelling velocity based on the retrieved correction amount of the belt travelling velocity corresponding to the detected phase of the belt.

Abstract: A control unit calculates a difference between a displacement of a belt detected by an encoder and a predetermined target value, calculates a pulse frequency of a driving pulse signal based on a feedback control based on the difference and a feed-forward control based on a reference driving pulse frequency, sets a control range of the feedback control to be equal to or smaller than a frequency of one rotation of a driven roller, and controls driving of a pulse motor such that the belt moves at a constant speed.

Abstract: An image forming apparatus is disclosed that includes an image carrier, a driving source, a rotation detection unit, and a control unit that performs fluctuation pattern recognition processing, control pattern construction processing, speed fine-adjustment processing, and remaining pattern recognition processing. The control unit is configured to perform control pattern correction processing for setting a frequency band of a remaining speed fluctuation to be detected by the remaining pattern recognition processing narrower than a frequency band of a speed fluctuation to be detected by the fluctuation pattern recognition processing and correcting the speed control pattern so as to be a pattern capable of reducing even the remaining speed fluctuation based on a remaining speed fluctuation pattern recognized by the remaining pattern recognition processing.