Abstract: An image forming apparatus that includes an image reading section, a transportation path, a photoreceptor, transferring area, a fixing area, and a feeding speed controller. The feeding speed controller selects the speed at which an original document passes through the image reading section between two speeds. A first speed is used when the transfer sheet is normal sized and for a period of time prior to a large sized sheet entering the fixing area. Once a large sized sheet enters the fixing area, the feeding speed controller changes the speed of the original document from the first speed to the second speed to provide proper scaling of the reproduced image on the transferred sheet. The second speed may be adjusted depending on the type of transfer sheet being used to take into account the amount of stretching of the material used to make the transfer sheet.

Abstract: A roll sheet cutter mechanism for an image forming apparatus is provided which is adapted to cut a roll sheet 4 paid out of a feed reel 51 between a rotary blade 82 and a stationary blade 81. When the leading edge of the transported roll sheet 4 passes over the rotary blade 82 located at a guiding position, the rotary blade 82 guides the leading edge of the roll sheet 4 in a transportation direction. The rotary blade 82 returns to a cutting stand-by position before the tail edge portion of the roll sheet 4 passes over the rotary blade 82. Therefore, the occurrence of jam of the roll sheet due to the curling thereof can assuredly be prevented. Further, time loss can be eliminated because the rotary blade is adapted to return to the cutting stand-by position.

Abstract: A copying machine that is capable of copying a large-size document original on a transfer sheet is provided in which the transfer sheet is prevented from being skewed from the desired transport path. In one embodiment, this bypass transportation path for a cut-sheet extends to a photoreceptor drum and is provided with a resist roller and a downstream transportation roller. A cut-sheet inserted from a manual sheet feeding section is stopped with its leading edge abutting against the resist roller, so that the leading edge of the cut-sheet is aligned with a line perpendicular to a transportation direction of the sheet. The cut-sheet is then transported by the resist roller and the transportation roller. At this time, the circumferential speed of the resist roller is slower by a predetermined degree than the circumferential speed of the transportation roller.

Abstract: In a coal-fired boiler, a heat recovery unit is located upstream of a dry electrostatic precipitator so as to reduce the temperature of exhaust gas flowing to the dry electrostatic precipitator and thus prevent reverse ionization in the electrostatic precipitator. The heat recovery unit located upstream of the dry electrostatic precipitator will in no way be corroded even if the concentration of dust is reduced in the dry electrostatic precipitator. A desulfurization unit does not require a cooling/dust removing section and eliminates the need for a wet electrostatic precipitator. The dry electrostatic precipitator includes a gas passage divided into a plurality of parallel passages and dampers operable to close the passages. This arrangement prevents dust from being dispersed as a result of hammering without charge.

Abstract: A sheet feeding apparatus provided with an urging device to urge the lift shaft, the lift gear or the lift plate in a direction opposite the insertion direction of the sheet feeding cassette, so as to disengage the lift shaft from the lift shaft drive. Insertion of the sheet feeding cassette pushes the lift shaft, lift gear or lift plate against the urging device, thereby engaging the lift shaft with the lift shaft drive. Alternately, rather than employing the urging device, the sheet feeding cassette may pull the lift shaft out of engagement with the lift drive by pulling the lifted lift plate in direction opposite the insertion direction of the sheet feeding cassette.

Abstract: A single tray serves both as an intermediate tray, for temporarily stacking paper sheets between copying operations thereon when such paper sheets are copies plural times, and as a paper discharging tray for stacking paper sheets subjected to final copying. The tray is arranged on the upstream side of a paper resupplying device. The tray includes a first paper stacking portion and a second paper stacking portion separable from each other. A paper discharging device is provided with a branching guide arranged at an upstream side of a paper discharging location for branching a paper sheet of maximum size on which an image has been formed toward the tray and positioned so that a leading end of the paper sheet when housed in the tray will not reach a paper resupplying roller of the paper resupplying device.