This invention provides a sheet conveying apparatus and an image forming apparatus excellent in reliability which maintain high productivity and yet can quickly detect bad conveyance when it occurs. A sheet feeding sensor is provided near the downstream side of a conveying roller and a retard roller, and a sheet discharge sensor is provided near the upstream side of discharge rollers, and when the length of a sheet in the direction of conveyance thereof is defined as Ls and the conveyance distance between the sheet feeding sensor and the sheet discharge sensor is defined as Lp and the number of sheets conveyed at a time at a spacing of zero (0) between sheets is defined as N, N is set so that Lp>Ls.times.N, and when the designated number of sheets is equal to or greater than N, N sheets as a set are conveyed at a spacing of zero (0) between the sheets, whereafter N sheets as a set are again conveyed at a predetermined spacing between the sheets detectable by the sensors, and this is repeated.

An image reading and recording apparatus provided with an image reading portion for reading the image of a document, and an image recording portion for recording an image on a recording sheet is provided with a first stacking portion for stacking thereon a first sheet which is one of the document and the recording sheet, a first feeding device for feeding the first sheet stacked on the first stacking portion, a second stacking portion for stacking thereon a second sheet which is the other of the document and the recording sheet, a second feeding device having a cut-away portion formed by cutting away a portion of the peripheral surface thereof and for feeding the second sheet stacked on the second stacking portion, and a lower guide member extending from the first stacking portion to the second feeding device for guiding the first sheet fed by the first feeding device, and when the first sheet is to be fed by the first feeding device, the second feeding device is stopped in a state in which the cut-away portion is opposed to the lower guide member so as to form between the cut-away portion and the lower guide member a gap through which the first sheet fed by the first feeding device passes.

An image forming apparatus has a sheet material conveying system for conveying the sheet material to an image forming device and has an image formation driving source for driving the image forming device. A control is provided to vary the speed at which the sheet material is conveyed by the image forming device according to the kind of sheet material used, to control the conveyance driving source and the image formation driving source such that the speed at which the sheet material is conveyed by the sheet material conveying system when an image is formed by the image forming device is substantially the same as the speed at which the sheet material is conveyed by the image forming device, and to control the conveyance system driving source and the image formation driving source such that the speed at which the sheet material is conveyed by the sheet material conveying system before image forming device starts to form an image is substantially the same as or faster than the speed at which sheet material is conveyed by the image forming device.

A guiding and positioning apparatus for accurate guiding and input of a print media sheet to a business machine. The guiding and positioning apparatus includes a rotating shaft, a retaining member, a guiding member, a sliding member, a roller, a first spring, a second spring, a tray and a positioning element. The rotating shaft has a protrusion, a first end and a second end. The retaining member is fitted on the first end. The guiding member is fitted on the second end. The sliding member is fitted on the rotating shaft. The sliding member has a sliding groove and a guiding groove. The roller is fitted on the rotating shaft. The first spring is disposed between the retaining member and roller. The second spring is disposed between the roller and sliding member. The tray is disposed under the roller. The positioning element is formed on one side of the tray.

A paper-pickup clutch of an automatic paper-feeding device includes a clamping member and a clamping-force adjusting member and can be applied to image processors such as printers, copiers or scanners. The automatic paper-feeding device includes a shaft and a paper-pickup mechanism transmitted to picking up paper by the shaft. The paper-pickup clutch provides a bi-directional clutch function by moving the clamping member toward or away from the paper-pickup mechanism with the clamping-force adjusting member in order to adjust the clamping force of the clamping member working on the paper-pickup mechanism to a certain level. With the certain level of clamping force, the paper-pickup mechanism sustains against paper to be fed and self-rotates with the rotation of the shaft in a first direction for feeding paper and rotates with the shaft in a second direction for releasing paper without further changing the state of the paper-pickup clutch.