Abstract: An image forming apparatus includes first and second image-forming portions and an intermediate transporting portion. A control unit checks fixing units in the image-forming portions and determines whether or not the fixing unit in the first image-forming portion is a fixing unit for an envelope. If not, the control unit controls a manipulation and display unit to display guidance for urging a user to exchange the first fixing unit. If so, the control unit determines whether or not too fixing unit in the second image-forming portion is a fixing unit for an envelope. If not, the control portion controls a manipulation and display unit to display a guidance for urging a user to exchange the second fixing unit. If both of fixing units in the first and second image-forming portions are fixing units for the envelope, the control unit allows an envelope mode control operation.

Abstract: In a serial tandem image forming system having a plurality of image forming apparatuses, a double-side printing job can be performed in a way according to the needs of users by taking into consideration an adjustment operation. The serial tandem image forming system includes an upstream apparatus 200 and a downstream apparatus 300, as the image forming apparatuses, each of which is capable of forming images on both sides of a sheet. When receiving a double-side printing job while one of the image forming apparatuses is performing the adjustment operation, a control unit 260 displays information on a manipulation display 500 which prompts a user to select whether to immediately start the job by performing a single machine double-side printing process with the other image forming apparatus, or start the job by shifting to a tandem mode and performing a serial double-side printing process after the adjustment operation has finished.

Abstract: An image forming system has a first image forming section to form an image on a sheet, wherein the first image forming section heats the sheet to fix the image on the sheet, a second image forming section to form an image to the sheet on which the image has been formed by the first image forming section, and a transporting section to transport the sheet from first image forming section to the second image forming section. The transporting section has a first transporting part to transport the sheet to a predetermined position, and a second transporting part to reverse a surface of the sheet which has been transported by the first transporting part as transporting the sheet from the predetermined position to an area below the predetermined position.

Abstract: An image forming apparatus including, a photosensitive body for carrying toner images, a transfer section for nipping the recording sheet at a position facing the photosensitive body and transferring the toner images carried on the photosensitive body onto a recording sheet, a driving section for driving the photosensitive body, and a control section for giving instructions to the driving section to conduct a velocity control to rotate the photosensitive body at a predetermined velocity, wherein the control section sets a gain of velocity control to be greater than normal condition, at a time which is at least one of a time when the recording sheet enters the transfer section, or a time when the recording sheet separates from the transfer section.

Abstract: In order that the air surrounding a fixing member is prevented from entering a blowing section for blowing separation air, a wind speed setting section is provided with switchable control modes, namely, a first control mode (control mode for operating the blower fan at a wind speed for separation) and a second control mode (control mode for operating the blower fan at a low speed). This structure allows the blower fan to be controlled in conformity to any one of these first and second control modes.

Abstract: An image forming apparatus including: a photoreceptor for bearing a toner image; a transfer body onto which the toner image borne by the photoreceptor is transferred; a drive section for driving the photoreceptor and transfer body respectively, and a control section for controlling the drive section so as to drive the photoreceptor and transfer body at a predetermined driving speed, wherein the control section, under a state in which the control section controls to drive the transfer body at the predetermined driving speed, controls to: a) drive the photoreceptor while changing the driving speed of the photoreceptor within a range of driving speeds between low speed and high speed, including the predetermined driving speed, b) extract torque characteristics under the control which includes the change of driving speed of the photoreceptor, and c) determine the driving speed of the photoreceptor based on the extracted torque characteristics.

Abstract: Disclosed is a fixing device, which makes it possible to prevent the air blasting section from deterioration, caused by heat transferred from the duct to the air blasting section. The fixing device includes a fixing section to fix the toner image onto the paper sheet; a heat source; and a separating section to separate the paper sheet from the pair of fixing members. On the other hand, the separating section includes: a gas blasting section to blast a gas; and a duct to guide the gas towards the pair of fixing members, and that is provided with a duct wall serving as a heat receiving surface to receive radiation heat irradiated from the fixing section, and at least one of the gas blasting section and the duct is provided with such a connection structure that suppresses heat transferring action from the duct to the gas blasting section.

Abstract: Provided is an image forming apparatus which enables quick removal of remaining sheets in the image forming apparatus via an orthogonal reverse section in case a jam occurs inside the image forming apparatus. The image forming apparatus includes a main conveyance section to convey a sheet in the image forming apparatus and to convey the sheet to an ejected sheet section; an orthogonal reverse section to receive the sheet from the main conveyance section and turn over the sheet without swapping a front edge for a rear edge of the sheet by conveying the sheet in a direction perpendicular to a sheet conveyance direction of the main conveyance section and a sheet ejection section to eject the sheet in the orthogonal reverse section outside the orthogonal reverse section along a direction to turn over the sheet by the orthogonal reverse section.

Abstract: In a serial tandem image forming system having a plurality of image forming apparatuses, a double-side printing job can be performed in a way according to the needs of users by taking into consideration an adjustment operation. The serial tandem image forming system includes an upstream apparatus 200 and a downstream apparatus 300, as the image forming apparatuses, each of which is capable of forming images on both sides of a sheet. When receiving a double-side printing job while one of the image forming apparatuses is performing the adjustment operation, a control unit 260 displays information on a manipulation display 500 which prompts a user to select whether to immediately start the job by performing a single machine double-side printing process with the other image forming apparatus, or start the job by shifting to a tandem mode and performing a serial double-side printing process after the adjustment operation has finished.

Abstract: A sheet reversing apparatus including: a right angle reversing conveyance section which reverses front/back sides of a sheet while changing a conveyance direction of the sheet, being conveyed in a first conveyance direction, to a second conveyance direction perpendicular to the first conveyance direction; a sheet skew sensor which detects a sheet skew of the sheet being conveyed by the right angle reversing conveyance section; and a sheet skew correction mechanism which corrects the sheet skew of the sheet while the sheet is being conveyed by the right angle reversing conveyance section.

Abstract: An image forming apparatus includes first and second. image-forming portions and an intermediate transporting portion. A control unit checks fixing units in the image-forming portions and determines whether or not the fixing unit, in the first image-forming portion is a fixing unit for an envelope. If not, the control unit controls a manipulation and display unit to display guidance for urging a user to exchange the first fixing unit. If so, the control unit determines whether or not too fixing unit in the second image-forming portion is a fixing unit for an envelope. If not, the control portion controls a manipulation and display unit to display a guidance for urging a user to exchange the second fixing unit, If both of fixing units in the first and second image-forming portions are fixing units for the envelope, the control unit allows an envelope mode control operation.

Abstract: An image forming apparatus including; an exposure section provided with, a light emitting element, a polygon mirror to receive light beams from the light emitting element, and to expose an image carrier using light beam via the polygon mirror based on image data; an image processing section to adjust image magnification by image processing of the image data; and, a control section configured to select at least either of a first magnification adjustment to change a rotation speed of the polygon mirror and a second magnification adjustment to carry out image processing of the image data by the image processing section, based on comparison results between a paper interval time during recording paper conveyance in image formation and the first magnification adjustment time required to stabilize polygon mirror rotation in the first magnification adjustment, when adjusting image magnification with respect to recording paper.

Abstract: In an image forming apparatus that forms a color image by transferring toner images for respective colors formed on plural rotary photoreceptor drums onto a sheet through an intermediate transfer member, when a controller judges that magnification deviation is generated in a main-scanning direction in superposition of the toner images for respective colors, the controller forms a first color registration deviation detecting mark for detecting at least an amount of deviation in the main scanning direction on the intermediate transfer member, and when the controller judges that the magnification deviation is not generated in the main-scanning direction in the superposition of toner images for respective colors, the controller forms a second color registration deviation detecting mark for detecting only an amount of deviation in a sub scanning direction perpendicular to the main-scanning direction on the intermediate transfer member.

Abstract: An image forming system has a first image forming section to form an image on a sheet, wherein the first image forming section heats the sheet to fix the image on the sheet, a second image forming section to form an image to the sheet on which the image has been formed by the first image forming section, and a transporting section to transport the sheet from first image forming section to the second image forming section. The transporting section has a first transporting part to transport the sheet to a predetermined position, and a second transporting part to reverse a surface of the sheet which has been transported by the first transporting part as transporting the sheet from the predetermined position to an area below the predetermined position.

Abstract: A color image forming apparatus for forming toner images by carrying out charging, exposure, and development on at least one photoreceptor drum, and forming color images by transferring the toner images onto sheets, the color image forming apparatus including: a photoreceptor drum which rotates around an axis; an exposure section which intermittently emits a light beam onto the cylindrical surface of the rotating photoreceptor drum along scanning lines parallel to the axis of the photoreceptor drum; a calculation section which calculates a printing ratio of a color image to be formed on one sheet, wherein the printing ratio is the ratio of the area covered by toner in the color image; and a timing control section which controls a timing when the exposure section emits the light beam in a direction of rotation of the photoreceptor drum based on the printing ratio calculated by the calculation section.

Abstract: A sheet reversing apparatus including: a right angle reversing conveyance section which reverses front/back sides of a sheet while changing a conveyance direction of the sheet, being conveyed in a first conveyance direction, to a second conveyance direction perpendicular to the first conveyance direction; a sheet skew sensor which detects a sheet skew of the sheet being conveyed by the right angle reversing conveyance section; and a sheet skew correction mechanism which corrects the sheet skew of the sheet while the sheet is being conveyed by the right angle reversing conveyance section.

Abstract: Provided is an image forming apparatus which enables quick removal of remaining sheets in the image forming apparatus via an orthogonal reverse section in case a jam occurs inside the image forming apparatus. The image forming apparatus includes a main conveyance section to convey a sheet in the image forming apparatus and to convey the sheet to an ejected sheet section; an orthogonal reverse section to receive the sheet from the main conveyance section and turn over the sheet without swapping a front edge for a rear edge of the sheet by conveying the sheet in a direction perpendicular to a sheet conveyance direction of the main conveyance section and a sheet ejection section to eject the sheet in the orthogonal reverse section outside the orthogonal reverse section along a direction to turn over the sheet by the orthogonal reverse section.

Abstract: Provided is an image forming apparatus having a first sheet dimension sensor at a conveyance path in a reverse conveyance section 50, wherein the first sheet detection sensor 75 detects a front edge and a rear edge of the sheet P in a sheet conveyance direction so as to detect a first sheet dimension. According to the above configuration, since only a sensor has to be disposed at the conveyance path in the reverse conveyance section 50 so as to detect the sheet dimension in the sheet conveyance direction, a first sheet dimension can be detected by an economical sensor configuration.

Abstract: An image forming apparatus including; an exposure section provided with, a light emitting element, a polygon mirror to receive light beams from the light emitting element, and to expose an image carrier using light beam via the polygon minor based on image data; an image processing section to adjust image magnification by image processing of the image data; and, a control section configured to select at least either of a first magnification adjustment to change a rotation speed of the polygon mirror and a second magnification adjustment to carry out image processing of the image data by the image processing section, based on comparison results between a paper interval time during recording paper conveyance in image formation and the first magnification adjustment time required to stabilize polygon mirror rotation in the first magnification adjustment, when adjusting image magnification with respect to recording paper.

Abstract: Provided is an operation panel using a touch panel method disposed on an image forming apparatus, wherein a CPU judges whether the same coordinate of an input section is in a pressurization when the operation panel is turned on and whether the first time period has elapsed while the above pressurization continues at the same coordinate, makes a display section to display a massage that the input section is unusable and a message to prompt a user to switch the input section to a substitution device, judges whether the pressurization continues after the second time period and the first time period have elapsed and makes the display section to display a warning to indicate that a malfunction occurs at the input section of the operation panel in case the input section is judged to be in the pressurization after the second time period elapsed.