Abstract: There is described an image forming apparatus, which forms high quality images free from a phenomenon of inter-sheet adhesion. The image forming apparatus includes a conveyance section to convey the transfer material along a conveying path; a cooling device disposed along the conveying path to cool the transfer material just after the toner image is fixed with heat; a controller-to control the conveyance section and the cooling device; and a first transfer-material detecting device disposed at a position adjacent to and upstream from the cooling device, in order to detect the transfer material coming into the conveying path. When the first transfer-material detecting device detects the transfer material coming, the controller controls the conveyance section to decelerate a conveyance velocity of the transfer material to a decelerated velocity lower than a normal conveyance velocity, so that the transfer material passes through the conveying path at the decelerated velocity.

Abstract: A tandem type color image forming apparatus which executes color misregistration correction, including: a detecting section which detects a width of a transfer sheet; an image forming section having an image carrier, on which arranged side by side are an image area where formed is an image for transfer and a non-image area where formed is the imprint image; and a control section which selects a complex or a single correction mode based on the transfer sheet width, to execute correction processing; where the complex correction mode is an operation mode of forming in parallel the image for transfer in the image area and the imprint image in the non-image area, and the single correction mode is an operation mode of suspending to form the image for transfer in the image area, and executing only to form the imprint image in the non-image area or in the image area.

Abstract: A signal processing apparatus comprising: an optical sensor for outputting a detection signal by detecting a surface of a recording medium on which a correction image is to be formed; and a control section configured to obtain a detection signal of the surface of the recording medium with the correction image from which a dominant frequency component has been deleted by making reverse frequency analysis of an analysis signal that has been obtained by making a frequency analysis of a detection signal outputted by the optical sensor detecting the surface of the recording medium on which the correction image it formed.

Abstract: An image forming apparatus is disclosed having a fixing unit having a heating device, for heat fixing, a heating power supply section which is connected to the fixing unit to supply electric power supplied from a commercial power supply to the heating device, a voltage detecting section for detecting a value of voltage supplied to the heating power supply section from the commercial power supply, and a control section that stops a supply of electric power to the heating device from the heating power supply section if a first voltage value is smaller than a standard voltage value, while, compares a second voltage value detected by the voltage detecting section after the lapse of the standard time with the standard voltage value, and conducts control to stop operations for image forming if the second voltage value is smaller than the standard voltage value.

Abstract: An image forming apparatus has a transfer attitude correcting section for correcting a transfer attitude of the transfer sheet to receive the toner image and for conveying the corrected transfer sheet to the transfer section with a timing to match with the movement of the toner image. The transfer attitude correcting section includes a roller unit including a base board rotatable around a center of rotation and a registration roller mounted on the base board, a detecting section for detecting a position of the transfer sheet being conveyed by the registration roller; and a control section for control the roller unit based on detection data detected by the detecting section so as to correct a skew of the transfer sheet by rotating the base board and to correct a deviation of a transfer position of the transfer sheet by shifting the registration roller on the base board.

Abstract: An induction heating type of fixing device to fix a recording material having a toner image thereon, having a heating member, an induction coil divided into a plurality of parts, a temperature detector for detecting a temperature of the heating member, a signal generator for generating a switching signal that periodically controls permission and prohibition of energization of each of the divided induction coils, and a controller for controlling supply of a driving current to each of the divided induction coils to heat the heating member. The controller controls the energization by periodically switching the driving current to each of the divided induction coils on the basis of an energization signal that determines the permission and the inhibition of the driving currents according to a signal of temperature detected by the temperature detector, and the switching signal.

Abstract: There is described an image forming apparatus, which forms high quality images free from a phenomenon of inter-sheet adhesion. The image forming apparatus includes a conveyance section to convey the transfer material along a conveying path; a cooling device disposed along the conveying path to cool the transfer material just after the toner image is fixed with heat; a controller-to control the conveyance section and the cooling device; and a first transfer-material detecting device disposed at a position adjacent to and upstream from the cooling device, in order to detect the transfer material coming into the conveying path. When the first transfer-material detecting device detects the transfer material coming, the controller controls the conveyance section to decelerate a conveyance velocity of the transfer material to a decelerated velocity lower than a normal conveyance velocity, so that the transfer material passes through the conveying path at the decelerated velocity.

Abstract: An image forming apparatus has a sheet feeding section for conveying a sheet for image formation, a stepping motor for driving the sheet feeding section, and a controller for controlling operation of the stepping motor. The controller includes a current value setting section. The current value setting section sets a current value that actuates the stepping motor based on sheet information obtained through at least one section selected from a thickness detecting section, size detecting section, and paper quality detecting section. The thickness detecting section detects a thickness of the sheet. The size detecting section detects a size of the sheet. The paper quality detecting section detects a paper quality of the sheet.

Abstract: In a fixing device of an image forming apparatus including a heating roller and a temperature detecting device spaced apart from the roller, having a first sensor for detecting the surface temperature of the roller, and a second sensor for detecting the ambient temperature, the first sensor being placed at a first position in a casing having an opening through which the heat radiation of the roller is directly incident and the second sensor being enclosed by the casing and placed at a second position to which the heat radiation of the roller is not directly incident, the temperature is calculated on the basis of the outputs of the two sensors, and the opening is disposed so as not to enter a region between the vertical plane containing the central axis of the roller and a tangential plane to the circumferential surface of the roller parallel to the vertical plane.

Abstract: This invention is directed to an image printing apparatus having a fixing control section which controls a fixing unit for fixing a toner image on a paper sheet by applying pressure and heat. The image printing apparatus of this invention includes, in the fixing control section, an interface which can receive data from an external data input device so as to shorten the warmup time of the fixing unit and perform direct instructing operation from the data input device to the fixing-unit.

Abstract: An induction heating type of fixing device to fix a recording material having a toner image thereon, having a heating member, an induction coil divided into a plurality of parts, a temperature detector for detecting a temperature of the heating member, a signal generator for generating a switching signal that periodically controls permission and prohibition of energization of each of the divided induction coils, and a controller for controlling supply of a driving current to each of the divided induction coils to heat the heating member. The controller controls the energization by periodically switching the driving current to each of the divided induction coils on the basis of an energization signal that determines the permission and the inhibition of the driving currents according to a signal of temperature detected by the temperature detector, and the switching signal.

Abstract: An image forming apparatus is disclosed having a fixing unit having a heating device, for heat fixing, a heating power supply section which is connected to the fixing unit to supply electric power supplied from a commercial power supply to the heating device, a voltage detecting section for detecting a value of voltage supplied to the heating power supply section from the commercial power supply, and a control section that stops a supply of electric power to the heating device from the heating power supply section if a first voltage value is smaller than a standard voltage value, while, compares a second voltage value detected by the voltage detecting section after the lapse of the standard time with the standard voltage value, and conducts control to stop operations for image forming if the second voltage value is smaller than the standard voltage value.

Abstract: This invention is directed to an image printing apparatus having a fixing control section which controls a fixing unit for fixing a toner image on a paper sheet by applying pressure and heat. The image printing apparatus of this invention includes, in the fixing control section, an interface which can receive data from an external data input device so as to shorten the warmup time of the fixing unit and perform direct instructing operation from the data input device to the fixing-unit.

Abstract: In a fixing device of an image forming apparatus including a heating roller and a temperature detecting device spaced apart from the roller, having a first sensor for detecting the surface temperature of the roller, and a second sensor for detecting the ambient temperature, the first sensor being placed at a first position in a casing having an opening through which the heat radiation of the roller is directly incident and the second sensor being enclosed by the casing and placed at a second position to which the heat radiation of the roller is not directly incident, the temperature is calculated on the basis of the outputs of the two sensors, and the opening is disposed so as not to enter a region between the vertical plane containing the central axis of the roller and a tangential plane to the circumferential surface of the roller parallel to the vertical plane.

Abstract: There is described an operation panel, which is detachably or movably mounted onto an image-forming apparatus, and which includes a data-inputting section to input operational data necessary for operating the image-forming apparatus and/or a displaying section to display status information of the image-forming apparatus. The operation panel comprises: a circuit board, on which electronic parts are mounted; a supporting member to support the circuit board, the data-inputting section and/or the displaying section, so as to integrate them into a single unit serving as the operation panel; a signal line, through which electronic signals are communicated between the operation panel and the image-forming section; and a conductive member for directly grounding at least one of the data-inputting section, the displaying section and the circuit board to a conductive main-frame of the image-forming apparatus.

Abstract: An image forming apparatus has a sheet feeding section for conveying a sheet for image formation, a stepping motor for driving the sheet feeding section, and a controller for controlling operation of the stepping motor. The controller includes a current value setting section. The current value setting section sets a current value that actuates the stepping motor based on sheet information obtained through at least one section selected from a thickness detecting section, size detecting section, and paper quality detecting section. The thickness detecting section detects a thickness of the sheet. The size detecting section detects a size of the sheet. The paper quality detecting section detects a paper quality of the sheet.

Abstract: There is described an operation panel, which is detachably or movably mounted onto an image-forming apparatus, and which includes a data-inputting section to input operational data necessary for operating the image-forming apparatus and/or a displaying section to display status information of the image-forming apparatus. The operation panel comprises: a circuit board, on which electronic parts are mounted; a supporting member to support the circuit board, the data-inputting section and/or the displaying section, so as to integrate them into a single unit serving as the operation panel; a signal line, through which electronic signals are communicated between the operation panel and the image-forming section; and a conductive member for directly grounding at least one of the data-inputting section, the displaying section and the circuit board to a conductive main-frame of the image-forming apparatus.