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: 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 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: 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.

Abstract: Provided is an image forming apparatus to form an image by scanning with a light beam through a polygon mirror, having a motor drive section to rotate and drive the polygon mirror based on a polygon drive clock pulse and an image processing section capable of adjusting image magnification through image processing, and a control section to control that at least image magnification adjustment by changing revolution of the polygon mirror or image magnification adjustment through the image processing in the image processing section is selected in accordance with an output form of the image when the image magnification is adjusted.

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: A fixing device includes: a fixing section which passes a sheet through a fixing nip portion formed by a pair of fixing members and thereby fixes a toner image on the sheet by heating; a blowing section which separates the sheet from the fixing members by blowing separation wind from a sheet discharge side of the fixing nip portion to the fixing members; an opening setting section which is provided with an opening region in which an opening width in a sheet width direction is adjustable, and adjusts a blowing range in the sheet width direction of the separation wind blown through the opening range from the blowing section to the fixing members; a temperature detection sensor for detecting temperature of the fixing members; and a control section which controls the opening width of the opening setting section based on the temperature detected of the fixing members.

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: 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: 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: An image-reading apparatus for reading an image formed on a document is provided which includes an automatic document feeder, a dynamic-document reading section, a static-document reading section, and a document-covering member. A light source mechanism irradiates an exposing light onto the document at either the dynamic-document reading section or the static-document reading section. A shutter member is provided which is movable between a shading position at which the shutter member blocks a portion of the emitted exposing light, and a non-shading position at which the shutter member does not block the exposing light. When the document is moved by the automatic document feeder at the dynamic-document reading section to read the image on the document, the shutter member is positioned at the non-shading position. When the document is stationarily placed on the static-document reading section to read the image, the shutter member is positioned at the shading position.

Abstract: An image forming apparatus, is provided with a fixing device including a heat source to receive power supply and to generate heat, and a temperature sensor to detect a temperature of the heat source; a control section to conduct a heat source temperature control and an abnormal temperature detecting control in response to a detection result of the temperature sensor; and an electric power cutout section to cut out the power supply to the heat source on a basis of the abnormal temperature detecting control by the control section. The control section conducts the heat source temperature control for the fixing device and/or the abnormal temperature detecting control for the electric power cutout section with at least two CPUs.