Abstract: A sheet feeding apparatus provided with a fan for blowing air against sheets stacked on a sheet tray, a position detecting sensor for detecting the position of the sheets floated up by the fan, and a tray lifting and lowering mechanism for lifting and lowering the sheet tray. The tray lifting and lowering mechanism is controlled on the basis of a result of detection by the position detecting sensor.

Abstract: Permanent magnets 52a1, 52a2 are inserted into magnet insert holes 51a1, 51a4 formed in a main magnetic pole 50A of a rotor 50. An outer circumferential surface of the rotor includes a first outer circumferential surface portion 50a which intersects with a d-axis and second outer circumferential surface portions 50da, 50ab which intersect with a q-axis. A radius R2 of curvature of the second outer circumferential surface portions 50da, 50ab is larger than a radius of curvature of the first outer circumferential surface portions 50a. Recesses 50a1, 50a2 are formed in the second outer circumferential surface portions 50da, 50ab and in a position to face end walls 51a2, 51a5 of the magnet insert holes 51a1, 51a4 which are adjacent to the outer circumferential surface of the rotor.

Abstract: An image forming apparatus which is capable of bringing processing devices, such as sheet feed devices and post-processing devices connected respectively to the image forming apparatus, into operable states in timing optimal for carrying out an image forming job, thereby improving productivity and operation rate of the image forming apparatus as well as saving energy. A print job is analyzed to determine at least one sheet feed device and at least one post-processing device to be used in executing the print job, and states of the determined devices are checked to determine at least one of the sheet feed device and the post-processing device to be caused to start a preparatory operation in advance before the print job is executed. Power supply to the at least one of the sheet feed device and the post-processing device is turned on in timing such that the preparatory operation is completed in time for the start of execution of the print job.

Abstract: In an image forming system having an image forming apparatus which forms an image onto a sheet and a sheet processing apparatus which is connected to the image forming apparatus and executes a post-process to the sheet, an abnormality in communication between the image forming apparatus and the sheet processing apparatus is detected, and when the communication abnormality is detected, an avoiding process for the abnormality is executed. A preprocess for a power shutdown is executed in accordance with an operation of a power switch to shut down a power source of the image forming system and, even if the communication abnormality is detected during the preprocessing step, the communication abnormality is ignored and the avoiding process is not executed.

Abstract: A sheet feeding apparatus provided with a fan for blowing air against sheets stacked on a sheet tray, a position detecting sensor for detecting the position of the sheets floated up by the fan, and a tray lifting and lowering mechanism for lifting and lowering the sheet tray. The tray lifting and lowering mechanism is controlled on the basis of a result of detection by the position detecting sensor.

Abstract: An image forming apparatus capable of efficiently performing an image forming processing even in a case where a post-processing apparatus performs a post-processing during a both-sides printing. A first time period needed by a first both-sides image forming processing and a second time period needed by a second both-sides image forming processing are computed in a case where a post-processing unit performs a post-processing on a recording sheet formed images on both sides thereof. The first time period and the second time period is compared, and any one of the first both-sides image forming processing and the second both-sides image forming processing is selected based on the comparison.

Abstract: An image forming apparatus in which surplus tabbed sheets produced in one set of output can be utilized for the next set of output, without requiring a user to perform a laborious task. In the image forming apparatus, a CPU calculates the number of tabbed sheet groups which will be used for one set of image formation and the number of tabbed sheets which will be used from among the last tabbed sheet group. Among the last tabbed sheet group, surplus tabbed sheets which will be left unused in the one set of image formation are determined. If the number of tabbed sheets is equal to or less than the number of the surplus tabbed sheets, at least one of the surplus tabbed sheets is used to carry out two sets of image formation.

Abstract: A bookbinding system includes an image forming apparatus and a bookbinding apparatus connected to the image forming apparatus. The bookbinding system includes an image forming unit to form an image on a recording sheet; a loading unit to load, as a bookblock stack, plural recording sheets on which images are formed; a bonding unit to form a booklet by bonding a cover with the bookblock stack; a setting unit to set a bookblock size, a cover size, and a finishing size; a cutting unit to cut the booklet bonded together with the cover into the finishing size; a stack thickness detection unit to detect a thickness of the bookblock stack; and a bookbinding permission/inhibition determination unit to determine permission/inhibition of a bookbinding operation based on a stack thickness detection result as well as the bookblock size, the cover size, and the finishing size set by the setting unit.

Abstract: A production process which comprises a preform formation step of forming a fiber preform made of silicon carbide short fibers having heat resistance of 1000° C. or greater; a sol-gel preparation step of preparing a sol-gel solution containing a heat resistant compound having heat resistance of 1000° C. or greater; an impregnation-drying-calcination step of impregnating the fiber preform with the sol-gel solution, followed by drying and calcining; and a crystallization step of crystallizing the fiber preform after impregnation, drying and calcination.

Abstract: A sheet processing device includes a transport cylinder, processing cylinder, and blowing device. The transport cylinder holds and conveys a sheet. The processing cylinder opposes the transport cylinder, and processes the sheet conveyed by the transport cylinder. The blowing device blows air to the sheet conveyed by the transport cylinder on an upstream side in a sheet convey direction of a contact position where the sheet conveyed by the transport cylinder comes in contact with the processing cylinder.

Abstract: There is provided an image forming apparatus which is capable of reducing a period of time required for obtaining an image output, in the case of changing the image forming operation from a monochromatic image formation to a color image formation during execution of the image forming operation. A plurality of image forming units form images and overlap images the formed images onto a transfer material. A preparation for image formation is started in a first mode in which image formation is carried out by the plurality of image forming units while image formation is being carried out in a second mode in which image formation is carried out by at least one of the image forming units. The image formation is carried out in the first mode after the image formation in the second mode is completed.

Abstract: An image forming system is provided that alleviates throughput reductions and enables reductions in power consumption and lower noise. The image forming system includes an image forming apparatus that forms an image on a recording material and a plurality of sheet-conveying devices that convey the recording material. Furthermore, the image forming apparatus includes a storage unit configured to store connecting orders of the plurality of sheet-conveying devices and a determination unit configured to determine which of the sheet-conveying devices should be given notification by an operation start request or an operation end request according to designation information that designates the sheet-conveying device to which the recording material is conveyed and the connecting orders for the plurality of sheet-conveying devices.

Abstract: A sheet processing apparatus is disclosed which is capable of preventing a motor from losing synchronization when initializing a roller position at power-up time, even if a diagonal feed mechanism does not have a sensor for detecting a position of a diagonal feed roller pair.

Abstract: There is provided an image forming apparatus which is capable of quickly performing measurements required for obtaining a proper image density. The image forming apparatus having a plurality of image forming apparatuses performs an image density adjustment control process by carrying out a maximum density control process at a reference image forming speed, and carrying out a density gradation control process at each of the plurality of image forming speeds. Image forming conditions for carrying out the density gradation control process at speeds other than the reference image forming speed are determined by performing operation on image forming conditions determined by the maximum density control process carried out at the reference image forming speed.

Abstract: A plate for a magnet cylinder includes a main body, a nonmagnetic portion, and a magnetic piece. The main body is formed of a flexible thin plate-like magnetic material to be magnetically mounted on the outer surface of a magnet cylinder. The nonmagnetic portion is projected from one end of the main body. The magnetic piece magnetically sandwiches the nonmagnetic portion against the outer surface of the magnet cylinder.

Abstract: A plate guide device includes a magnet cylinder and guide plate. A plate is to be mounted magnetically on the outer surface of the magnet cylinder. The guide plate guides the plate removed from the magnet cylinder.

Abstract: An image forming apparatus has a calibration mode in which a calibration image is formed on a print medium to correct image forming conditions. The image forming apparatus detects print medium information to determine, on the basis of the print medium information, whether the print medium is a sheet recommended as a print medium for use in the calibration mode. The image forming apparatus sets calibration conditions corresponding to the determined recommended sheet. The image forming apparatus corrects the image forming conditions on the basis of the set calibration conditions.

Abstract: A sheet conveying apparatus includes first and second conveying paths. The first conveying path is configured to receive a sheet from a device connected at an upstream side in a sheet conveying direction so as to transfer the sheet to a device connected at a downstream side in the sheet conveying direction. The second conveying path intersects with the first conveying path. A controller switches between a first operation mode and a second operation mode. In the first operation mode, the sheet is conveyed along the first conveying path, and in the second operation mode, the sheet is conveyed along the second conveying path. The controller controls a sheet conveying operation in the first operation mode or the second operation mode in accordance with the state of the sheet on the second conveying path.

Abstract: In a sheet conveyance system in which a plurality of apparatuses each including a communication unit with a plurality of communication channels are connected, and a sheet is conveyed between the apparatuses, each of the plurality of communication channels can be switched between a transmission mode and a reception mode. When a plurality of transmission channels are set by channel assignment, communication can be executed by giving a priority to each transmission destination. If transmission data are accumulated in an apparatus, and they include data for a transmission destination with a higher priority over the current data transmission destination, the number of transmission channels is increased, and the priority is raised.

Abstract: In an image forming system having an image forming apparatus which forms an image onto a sheet and a sheet processing apparatus which is connected to the image forming apparatus and executes a post-process to the sheet, an abnormality in communication between the image forming apparatus and the sheet processing apparatus is detected, and when the communication abnormality is detected, an avoiding process for the abnormality is executed. A preprocess for a power shutdown is executed in accordance with an operation of a power switch to shut down a power source of the image forming system and, even if the communication abnormality is detected during the preprocessing step, the communication abnormality is ignored and the avoiding process is not executed.