Abstract: A device for developing an electrostatic latent image that includes a developing roller which is disposed in a developing housing, holds the developing agent on its peripheral surface, and conveys the developing agent that is held to a developing zone, a feeding roller for feeding the developing agent onto the peripheral surface of the developing roller, and seals that are disposed so as to be opposed to both ends of the developing roller from the downstream side of the developing zone to the upstream side of a developing agent-limiting zone. The device further includes seal lips that are formed in a protruding manner and which extend from one end on the side of the developing zone to an opposite end on the side of the developing agent-limiting zone. The feeding or replenishing roller is positioned so that its end surfaces are in contact with the inner end surfaces of the seals.

Abstract: A device for developing an electrostatic latent image includes a developing housing having a developing chamber and stirrer chamber, a replenishing device for feeding the developing agent onto the peripheral surface of the developing roller, a stirring device disposed in the stirrer chamber to stir the developing chamber, and a developing agent detecting sensor disposed in the developing housing under the stirring device. The stirring device has a rotary shaft, a cleaning member mounted on the rotary shaft at a position corresponding to a development agent detector unit of the developing agent detecting sensor, and a stirrer member mounted on the rotary shaft at the side of the cleaning member. The stirrer member is provided with tilted guide portions for sending the stirred developing agent toward the developing agent detecting sensor.

Abstract: A device for developing an electrostatic latent image including a developing housing having a developing chamber, a stirrer chamber, and a developing agent-feeding port communicating with the stirrer chamber. A developing roller is disposed in the developing chamber to hold, on the peripheral surface thereof, a developing agent in a developing agent-holding zone, and convey the thus held developing agent to a developing zone to apply it to the electrostatic latent image. A replenishing device feeds the developing agent onto the peripheral surface of the developing roller in the developing agent-holding zone. A stirring device disposed in the stirrer chamber stirs the developing agent that is fed through the developing agent-feeding port and sends the stirred developing agent to the developing chamber. A vibration plate having a plurality of developing agent-flow ports is disposed at the developing agent-feeding port of the developing housing, and the stirring device is caused to act on the vibration plate.

Abstract: A discharge device is usable for an image forming apparatus including a fixing portion having a heating roller in the shape of a hyperboloid for fixing a toner image formed on an envelope having a turned-up portion, and a stacking portion for stacking envelopes. The discharge device provided with a discharge roller system provided between the fixing portion and the stacking portion to discharge the envelope to the stacking portion has a upright portion provided near the discharge roller system below the transport path of the envelope to prevent the turned-up portion of the envelope from warping downward. This discharge device prevents a discharging envelope from coming into contact or colliding with the uppermost one of a stack of already discharged envelopes on the stacking portion, and enables the envelopes to be discharged suitably and to be stacked orderly on the stacking portion and increases an amount of envelopes stacked on the stacking portion.

Abstract: A copy item transport device is used in an image forming apparatus having an image bearing member and a pair of registration rollers before the image bearing member, and includes a separator for regulating multiple copy items to one copy item for each image formation. The separator is constructed by a forward roller being driven in a forward direction of transporting the copy item to the registration roller pair, a reverse roller in contact with the forward roller. The reverse roller is driven in a reverse direction of transporting the copy item backward, but rotatable in the forward direction together with the forward roller when receiving a greater transmitted forward torque from the forward roller than the reverse torque. The reverse drive to the reverse roller is stopped at the same time or after the forward drive to the forward roller is stopped to assure the nip of copy item by the registration roller pair.

Abstract: A sheet discharging device is used in an image forming apparatus including fixing means adopting heat roller fixing method of fusing a toner image transferred to a sheet so as to fix the same on the sheet while transporting the sheet by heating and pressing rollers rotated at a specified speed. This sheet discharging device is provided with a sheet discharger including first and second rollers and arranged downstream from the fixing device, a contact point of the first and second rollers being located toward the pressing roller from a tangent line on a point of a circumferential surface of the heat heating roller which intersects with a straight line connecting centers of the heating and pressing rollers, and a drive mechanism for driving the first roller and the heating roller so that a speed of the first roller at the circumferential surface thereof is greater than that of the healing roller. Accordingly, a sheet curled in the fixing device can be straightened with a simple construction.

Abstract: An image forming apparatus includes a mount portion which permits a cassette containing a plurality of stacks of sheets arranged side by side in rows to be mounted to the image forming apparatus; a feeder for feeding sheets side by side in a state where the cassette is mounted to the mount portion; an imaging assembly for forming an image on each of the sheets being fed side by side; a sheet sensor for detecting the presence or absence of a sheet contained in the cassette for each row; and a control unit for, when the absence of a sheet is detected in any of the rows, stopping at least an image forming operation along a corresponding transport path. Accordingly, even if all the sheets run out in any one of the rows, the corresponding transport path and the like can be prevented from getting smeared due to the image forming operation carried out despite the fact that no sheets are being fed.

Abstract: A sheet feeder includes a feeder for feeding a sheet, a cassette for containing a plurality of stacks of small sized sheets side by side therein, the cassette including a plurality of biasing members for biasing the respective stacks of small sized sheets upwards so as to bring uppermost sheets of the respective stacks into contact with the feeder, a plurality of sheet detectors arranged in positions corresponding to the respective stacks of sheets for detecting the height of the respective stacks of sheets contained in the cassette, and a controller responsive to the plurality of sheet detectors for determining the absence of sheet in the cassette when at least one of the plurality of sheet detectors detects that the height of the stack has become lower than a predetermined height, and stopping a sheet feeding operation. This sheet feeder prevents the transfer device of an image forming apparatus from being smeared due to the fact that the small sized sheet is fed from only one stack.

Abstract: A cassette is attachable to an image forming apparatus including a feed roller. The cassette is provided with a push-up member for pushing up leading edges of sheets placed in the cassette so as to bring the uppermost one of the contained sheets into contact with the feed roller, and a restricting member for restricting displacement of the contained sheets from a specified position. By attaching thus constructed cassette to the image forming apparatus, sheets can be fed properly by the feed roller.

Abstract: A parallel transport apparatus for transporting sheets side by side along a plurality of transport paths is provided with a feed roller which is brought into contact with uppermost sheets of a plurality of stacks of sheet contained side by side in a cassette and is adapted for feeding the uppermost sheets side by side; a separation roller pair arranged at a specified position of each of the plurality of transport paths and adapted for separating the sheets fed side by side so that one each of sheets are transported along the respective transport paths simultaneously; a sheet detector arranged downstream from the separation roller pair with respect to a sheet transport direction and adapted for detecting the presence or absence of sheets being transported side by side; and a multifeed discriminator for discriminating whether the multiple feeding has been occurred along any of the transport paths in accordance with an output from the sheet detector.

Abstract: A cassette for feeding sheet materials is equipped with a container body in which two sheet material-holding devices are arranged in parallel in the direction of width. Each of the sheet material-holding devices includes a pair of width restriction members which are so disposed that their positions can be freely adjusted in the direction of width. Each of the sheet material-holding devices further includes a rear end restriction member that is so disposed that its position can be freely adjusted in the feeding direction.