Abstract: An image forming apparatus has rotatable members for rotatably retaining respective ones of flanges mounted to opposite ends of a roll sheet, and placement stages on which the roll sheet is to be placed and on which respective ones of the rotatable members are mounted. Racks are mounted to respective ones of the placement stages for undergoing movement to move the placement stages relative one another to vary a distance between the placement stages. A pinion is arranged between the racks for undergoing rotation to move the racks, and a potentiometer whose resistance value varies in accordance with a distance between the placement stages undergoing movement with rotation of the pinion is provided. An A/D converter outputs a value based on a resistance value of the potentiometer. A calculation device calculates a width of the roll sheet based on the value output from the A/D converter. A memory stores the calculated width of the roll sheet.

Abstract: An image forming apparatus has rotatable members for rotatably retaining respective ones of flanges mounted to opposite ends of a roll sheet, and placement stages on which the roll sheet is to be placed and on which respective ones of the rotatable members are mounted. Racks are mounted to respective ones of the placement stages for undergoing movement to move the placement stages relative one another to vary a distance between the placement stages. A pinion is arranged between the racks for undergoing rotation to move the racks, and a potentiometer whose resistance value varies in accordance with a distance between the placement stages undergoing movement with rotation of the pinion is provided. An A/D converter outputs a value based on a resistance value of the potentiometer. A calculation device calculates a width of the roll sheet based on the value output from the A/D converter. A memory stores the calculated width of the roll sheet.

Abstract: An image forming apparatus has an image transferring portion for transferring an image onto a sheet, an image fixing portion for fixing the transferred image to the sheet, a sheet conveyor portion arranged between the image transferring portion and the image fixing portion for conveying the sheet in a sheet conveying direction, a support portion having an elliptical-shaped shaft hole extending in a direction crossing the sheet conveying direction, and an arm rotatably mounted on the support portion. A first spur is disposed at a position opposed to the sheet conveyor portion and is rotatably supported by the support portion and movable along the shaft hole. A second spur is disposed at a position opposed to the sheet conveyor portion downstream in a sheet conveying direction of the first spur and closer to the sheet conveyor portion than the first spur. The second spur is rotatably supported by the arm and has a movable range larger than a movable range of the first spur.

Abstract: An image forming apparatus includes a photosensitive drum for transferring an image onto a sheet and an image roller and a pressure roller for fixing the image transferred onto the sheet to the sheet. A conveying portion and a guide plate constitute a sheet conveyor portion positioned between the photosensitive drum, and the image roller and pressure roller. The image forming apparatus includes a first spur disposed at a position opposed to the guide plate and a second spur disposed at a position opposed to the guide plate downstream in a sheet conveying direction of the first spur and closer to the guide plate than the first spur.

Abstract: Provided is an image forming apparatus for preventing a paper sheet such as a plain paper or a tracing paper from being waved immediately after fixation. Between a fixing roller (17) of a fixing roller pair in a fixing unit and a delivery roller (19) in a delivery unit, there is provided a unit for regulating a delivery direction of the paper sheet. The delivery direction of the paper sheet is once forcibly directed upward or downward with respect to a tangential direction of a nip portion of the fixing roller pair, thereby preventing waving of the paper sheet.