An image forming apparatus includes a cassette that has a placement plate on which a sheet is set, a paper feed roller, a raising/lowering mechanism that raises and lowers the placement plate, a print unit, a sheet sensor, an upper limit sensor and a control unit. The control unit recognizes, based on an output of the sheet sensor, that the sheet supplied from a paper feed device reaches an installation position of the sheet sensor. The control unit detects, based on an output of the upper limit sensor, that the paper feed roller reaches a predetermined upper limit position or that the raising/lowering mechanism raises the placement plate such that the sheet reaches a feed position and uses the sheet sensor and the upper limit sensor so as to detect that the paper feed device encounters overload.

An image forming apparatus includes a drive device including a first drive transmission passage through which a driving force of a drive source is transmitted to a developer bearer via a first joint and a second drive transmission passage through which the driving force is transmitted to a rotary body via a second joint. The first drive transmission passage and the second drive transmission passage are defined such that one of a first drive transmission ratio to the first joint of the first drive transmission passage and a second drive transmission ratio to the second joint of the second drive transmission passage is an integral multiple of the other of the first drive transmission ratio from the drive source to the first joint of the first drive transmission passage and the second drive transmission ratio from the drive source to the second joint of the second drive transmission passage.

An image forming apparatus including a normal power mode and a power saving mode includes a fixing unit configured to bring first and second rotary members into contact with each other to form a nip portion and fix a toner image onto a sheet with a pressing force of the nip portion. The image forming apparatus executes a rotation operation or a separation operation to separate the first and second rotary members from each other in order to prevent a deformation of the nip portion in the fixing unit. The image forming apparatus measures a time during which the first and second rotary members are in contact with each other without rotating. The image forming apparatus determines whether to execute the separation operation or the rotation operation based on a result of the power mode determination and the measured time.

An image forming system of an aspect of the present invention includes: a first image forming portion; a second image forming portion connected in series to the first image forming portion; and an assignment determining portion that determines an assignment of image formation of print data to the first image forming portion and the second image forming portion in accordance with contents of the print data. The first image forming portion forms a first image on the continuous sheet on the basis of the assignment determined by the assignment determining portion, and the second image forming portion forms a second image on a region which is different from a region where the first image is formed on the continuous sheet and which overlaps a non-printable region that is a region where the first image forming portion cannot print, on the basis of the assignment determined by the assignment determining portion.

A conveyance apparatus includes a separation unit configured to separate and convey a sheet, a detection unit configured to detect a height-direction deformation of the sheet passing through the separation unit on a downstream side than a sheet-conveying position of the separation unit in a conveyance direction of the sheet, and a control unit configured to stop the sheet conveyed by the separation unit if the detection unit detects the deformation of the sheet.

In an image forming apparatus that employs a laser scanning optical system that does not use an fθ lens, in the case where magnification correction by insertion/removal of an auxiliary pixel is performed based on the premise of digital PWM, an insertion/removal position of an auxiliary pixel is controlled in accordance with a purpose of each piece of image processing.

An image reading apparatus includes a reading unit, a conveyance unit configured to convey the sheet, a support portion configured to support the conveyance unit openably and movably with respect to the reading unit in a vertical direction between an upper position and a lower position, a bundled wire transmitting a signal or electric power to the conveyance unit, and a cover portion configured to cover the bundled wire. The cover portion includes a first cover member provided on the conveyance unit and a second cover member provided movably in the vertical direction with respect to the reading unit. A whole length of the cover portion in the vertical direction in a case where the conveyance unit is located at the upper position is longer than a whole length of the cover portion in a case where the conveyance unit is located at the lower position.

An electrophotography-based additive manufacturing system is used to print a three-dimensional part. An electrophotography engine is used to print a part layer of the three-dimensional part is using a part material compositionally including part material particles. The developed part layer is transferred from the electrophotography engine to a transfer medium, and the transferred part layer is transfused together to previously-printed layers using a layer transfusion assembly. A surface height profile of the transfused part layers is measured using a surface profilometer, and a thickness profile of a subsequently-printed part layer is controlled responsive to the measured surface height profile.

An electrophotography-based additive manufacturing system is used to print a three-dimensional part. An electrophotography engine is used to print a part layer of the three-dimensional part is using a part material compositionally including part material particles. The developed part layer is transferred from the electrophotography engine to a transfer medium, and the transferred part layer is transfused together to previously-printed layers using a layer transfusion assembly. A surface height profile of the transfused part layers is measured using a surface profilometer, and a thickness profile of a subsequently-printed part layer is controlled responsive to the measured surface height profile.

An image forming apparatus includes an image bearing member, a developer bearing member, a discharge unit, a stacking tray including a stacking surface on which the recording material is stacked, a replenishment port, a cover capable of moving between a closed position where the cover covers the replenishment port and constitutes at least part of the stacking surface and an open position where the cover exposes the replenishment port, and an information display unit for displaying information about a procedure for replenishing the developing container with the developer from the replenishment container.