Abstract:
A fixing apparatus is provided with a fixing device which includes a fixing roller and a pressing roller pressed against the fixing roller, the fixing roller and the pressing roller defining a region through which sheets of various sizes pass while being heated, an induction-heating device which heats the fixing roller by induction heating and which includes first and second excitation coil units provided inside the fixing roller and spaced from each other by a predetermined distance in an axial direction of the fixing roller, and a control device which varies an output applied to the first and second excitation coils in accordance with a surface temperature as measured in the axial direction of the fixing roller. The first and second excitation coil units have widths which are greater than those of maximal-size sheets by 20 to 40 mm.
Abstract:
A technique of preventing toner from adhering to a guide which guides a change of a conveying direction of a paper by the paper on which a toner image is formed contacting with the guide is provided. The technique includes: a concave guide, having a concave guide surface, which guides conveyance of a paper so as to change a conveyance direction of the conveyed paper; and a guiding roller provided in the vicinity of a position on the guide surface of the concave guide where a front edge of the paper conveyed toward the concave guide abuts so as to have a roller surface project from the guide surface.
Abstract:
According to an embodiment of the invention, an image forming apparatus comprises a fixing unit including: a pair of rollers rotating with a recording sheet holding a toner image interposed therebetween; a driving motor rotating at least one of the pair of rollers; a heater being built in at least one of the pair of rollers to heat the roller; a timer measuring a period of time after starting operation; and a rotation speed control unit controlling the driving motor so that one of the rollers rotates in a speed higher than a rotation speed under normal conditions until a predetermined time measured by the timer.
Abstract:
A developer image is formed by selectively supplying a developer based on a potential distribution corresponding to image information, the formed developer image is electrostatically attracted and transferred to a sheet material, the developer image is fixed to the sheet material by applying heat and pressure to the developer image transferred to the sheet material and the sheet material, and a drive force in a forward direction applied to the sheet material is cut off in a case where the sheet material is not ejected in a specified time, and then a drive force in a direction opposite to that of the drive force in the forward direction is applied for a specified time, and therefore, it is possible to prevent a sheet jammed in a fuser unit from being concealed in the fuser unit.
Abstract:
A technique of preventing toner from adhering to a guide which guides a change of a conveying direction of a paper by the paper on which a toner image is formed contacting with the guide is provided. The technique includes: a concave guide, having a concave guide surface, which guides conveyance of a paper so as to change a conveyance direction of the conveyed paper; and a guiding roller provided in the vicinity of a position on the concave guide surface of the concave guide where a front edge of the paper conveyed toward the concave guide abuts so as to have a roller surface project from the concave guide surface.
Abstract:
A fixing device has a separation claw whose end portion is installed touchably with an outer periphery surface of a press roller. The separation claw makes the end portion make contact with the outer peripheral surface of the press roller, thereby separates a paper from the press roller. A rotation central shaft of the separation claw is rotatably supported by a support member and when force for pressing the end portion of the separation claw inside the press roller is given, the rotation central shaft of the separation claw is led so that the end portion of the separation claw is shifted in the direction of separating from the press roller.