Abstract: The present invention provides an image forming apparatus which, when switching operation from color image forming operation to monochromatic image forming operation, forms a monochromatic image on each of a prescribed number of sheets by stopping a part of the functions of yellow, magenta and cyan image forming sections of the color image forming operation, and thereafter, forms a monochromatic image only with a black-only image forming section, thereby permitting extension of service life of the image forming sections, while improving the productivity.

Abstract: A motor drive control apparatus which are capable of improving quietness during operation of a motor without the need of modifying the motor driving circuit and without increasing the load torque on the motor. The motor drive control apparatus is connected to a pulse motor via a driving gear disposed on an output side of the motor, and a driven gear engaging the driving gear. The motor drive control apparatus performs drive control in which the motor is driven to transmit a driving force of the motor to a load via the driving gear and the driven gear, and performs position control in which the driving gear is moved by a predetermined amount such that a gap formed between the driving gear and the driven gear is reduced or removed, before the drive control is performed. The drive control is performed when a predetermined period of time has elapsed after the position control is performed.

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: An image forming apparatus including an image forming unit for forming an image on a recording sheet including a special sheet, and a controller for allowing the image forming unit to carry out an image forming sequence which forms an image on the recording sheet, wherein the controller allows the image forming unit to control a cleaning operation of the image forming unit in response to image formation on the special sheet by the image forming unit.

Abstract: A fixing apparatus for fixing a toner image on a recording material by heat has a pair of rotary members having a heat generating member, and rotatable in contact with each other, electric power supply controller for controlling electric power supply to the heat generating member so that the temperature of at least one of the rotary members may become a set temperature, and rotation time setting unit for setting a time for which the electric power supply control is effected after the shift from a warming-up operation to a fixing capable state and the pair of rotary members are rotated continuously from rotation during the warming-up operation, on the basis of the time of the warming-up operation.

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 includes an apparatus main assembly, and a process cartridge detachably mountable to the apparatus main assembly, including a driving force receiver to be connected to a driver of the apparatus main assembly and a non-contact memory for carrying out non-contact data communication with a receiver of the apparatus main assembly, wherein the apparatus main assembly performs rotational driving of the driver before reading out data from the non-contact memory.

Abstract: There is provided an image forming apparatus of the type that a toner image, which is transferred onto an intermediate transfer member, onto a sheet material, is transferred onto a sheet material, which is capable of reducing the possibility of leading end misalignment even if there is a delay in conveyance of the sheet material. An image forming device forms an image on a photosensitive member. An image carrier carries an image. A first transfer device transfers the image carried by the image carrier onto a sheet. A second transfer device transfers the image transferred onto the image carrier onto a sheet. A feeding device feeds the sheet. A conveying device conveys the sheet fed by the feeding device to the second transfer device. A controller controls the conveying device to cause the sheet to be temporarily stopped at a first location and a second location between the feeding device and the second transfer device.

Abstract: There is provided an image forming apparatus which is capable of operating in a stable condition and in an efficient manner by omitting automatic adjustment in the case where there is no necessity of carrying out the automatic adjustment when the image forming apparatus returns from a power-saving mode to a normal mode. A CPU shifts the operation mode of the image forming apparatus to a power-saving mode in which power consumption is saved. The CPU detects at least one of a status of the image forming apparatus before the operation mode is shifted to the power-saving mode and a status of the image forming apparatus in the power-saving mode. The CPU determines the contents of a return process executed when the operation mode returns to a normal mode from the power-saving mode, according to the detected status of the image forming apparatus.

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: The present invention provides an image forming apparatus which, when switching operation from color image forming operation to monochromatic image forming operation, forms a monochromatic image on each of a prescribed number of sheets by stopping a part of the functions of yellow, magenta and cyan image forming sections of the color image forming operation, and thereafter, forms a monochromatic image only with a black-only image forming section, thereby permitting extension of service life of the image forming sections, while improving the productivity.

Abstract: An image forming apparatus includes an apparatus main assembly, and a process cartridge detachably mountable to the apparatus main assembly, including driving force receiving means to be connected to driving means of the apparatus main assembly and a noncontact memory for carrying out noncontact data communication with receiving means of the apparatus main assembly, wherein the apparatus main assembly performs rotational drive of the drive means before reading out data from the noncontact memory.

Abstract: There is provided an image forming apparatus capable of setting up a tab sheet mode-operating and configuring environment in which an effective tab sheet mode output can be obtained by a simple operation of selecting feeding of tab sheets and a destination of discharge of the tab sheets. A controller is responsive to instruction of feeding of the tab sheets, for providing control to automatically select the cassettes 21a-21d or the multi manual feed tray 27 or the deck 28 that can feed tab sheets that enable a valid image transfer result to be obtained, according to a sheet discharge destination selected by a user for the face-up discharge tray 2 or the face-down discharge tray 3 and a page order designated for the cassettes 21a-21d or the multi manual feed tray 27 or the deck 28, which is indicated by sheet management information.

Abstract: There is provided an image forming apparatus of the type that a toner image, which is transferred onto an intermediate transfer member, onto a sheet material, is transferred onto a sheet material, which is capable of reducing the possibility of leading end misalignment even if there is a delay in conveyance of the sheet material. An image forming device forms an image on a photosensitive member. An image carrier carries an image. A first transfer device transfers the image carried by the image carrier onto a sheet. A second transfer device transfers the image transferred onto the image carrier onto a sheet. A feeding device feeds the sheet. A conveying device conveys the sheet fed by the feeding device to the second transfer device. A controller controls the conveying device to cause the sheet to be temporarily stopped at a first location and a second location between the feeding device and the second transfer device.

Abstract: The present invention has as its object to prevent faulty fixing after rising, and in order to achieve this object, a fixing apparatus for fixing a toner image on a recording material by heat has a pair of rotary members having a heat generating member, and rotatable in contact with each other, electric power supply control means for controlling electric power supply to the heat generating member so that the temperature of at least one of the rotary members may become a set temperature, and rotation time setting means for setting a time for which the electric power supply control is effected after the shift from a warming-up operation to a fixing capable state and the pair of rotary members are rotated continuedly from rotation during the warming-up operation, on the basis of the time of the warming-up operation.

Abstract: An image forming apparatus including an image forming unit for forming an image on a recording sheet including a special sheet, and a controller for allowing the image forming unit to carry out an image forming sequence which forms an image on the recording sheet, wherein the controller allows the image forming unit to control a cleaning operation of the image forming unit in response to image formation on the special sheet by the image forming unit.

Abstract: An image forming apparatus has a feeder for feeding a sheet, an image forming unit for performing an image formation job so as to form an image on a sheet fed from the feeder, a controller for interrupting a current image formation job, performing an interrupt image formation job, and resuming the current image formation job after completion of the interrupt image formation job. When the current image formation job uses a sheet feeder for feeding sheets set in a predetermined order, the controller prevents the sheet feeder used in the current image formation job from being used in the interrupt image formation job.

Abstract: An image forming apparatus capable of printing images on tab-sheets as well as on normal sheets can automatically perform a mixed printing job including image printing for the normal sheets and image printing for the tab-sheets. The apparatus makes it possible to use image information a number of times and that preparation of the image information is easy. In the apparatus, image information of a text sheet document to be printed on the text sheets and image information of a tab-sheet document to be printed on the tab-sheet are separately inputted to the apparatus and separately stored in an image memory in advance. The apparatus performs combined printing in which printing of the image information of the text sheet document stored in the image memory and printing of the image information of the tab-sheet document stored in the image memory are so combined that the printings of the pages of the tab-sheet document are inserted intervening in the printing of the text sheet document at designated page positions.

Abstract: In an image reading apparatus having a document feeder adapted to convey an original, an image sensor adapted to read the original conveyed to a platen by the document feeder, and a memory adapted to store image data for each pixel, control is executed to cause the image sensor to execute reading at a predetermined position a plurality of number of times without placing any original on the platen while driving the original convey member of the document feeder, the image data of the original output from the image sensor is compared with the image data of a corresponding pixel, which is stored in the memory, every time the original convey member is read, the image data stored in the memory is updated to data having a larger value, and the presence/absence and position of dust and/or dirt on the platen are detected on the basis of the number of times of reading the original convey member and the image data stored in the memory after the end of a plurality of number of times of reading the original convey member.