Abstract: A belt drive apparatus includes: a rotatable first roller; a rotatable second roller; a belt member stretched by the first and the second rollers so as to be capable of being conveyed by the first roller and the second roller; and a restraint member provided on at least one of the two ends of the second roller and including a belt receiving surface to be brought into contact with an edge portion of the belt member. The belt receiving surface and an axis of the second roller make an angle that is not smaller than 93° but not larger than 115°.

Abstract: An image forming apparatus includes a medium placing portion on which a medium is placed, a feed roller rotatably provided in contact with the medium placed on the medium placing portion so as to feed the medium, guide members disposed on both sides of the feed roller for guiding the medium being fed. The guide members are movable in a direction substantially perpendicular to a surface of the medium. A biasing unit is provided for biasing the guide members in a direction toward the medium.

Abstract: A medium transportation apparatus is provided with a plurality of medium transportation units, a drive source, a sun gear connected to the drive source, a planetary gear engaging the sun gear for transmitting a drive force to one of the medium transportation units according to a rotational direction of the sun gear, and a rotational load member for applying a rotational load to the planetary gear. The rotational load member is disposed on an outer side relative to a rotational shaft of the planetary gear in a radial direction of a rotational shaft of the sun gear.

Abstract: A belt drive apparatus includes: a rotatable first roller; a rotatable second roller; a belt member stretched by the first and the second rollers so as to be capable of being conveyed by the first roller and the second roller; and a restraint member provided on at least one of the two ends of the second roller and including a belt receiving surface to be brought into contact with an edge portion of the belt member. The belt receiving surface and an axis of the second roller make an angle that is not smaller than 93° but not larger than 115°.

Abstract: An image forming apparatus includes a medium placing portion on which a medium is placed, a feed roller rotatably provided in contact with the medium placed on the medium placing portion so as to feed the medium, guide members disposed on both sides of the feed roller for guiding the medium being fed. The guide members are movable in a direction substantially perpendicular to a surface of the medium. A biasing unit is provided for biasing the guide members in a direction toward the medium.

Abstract: A medium transportation apparatus is provided with a plurality of medium transportation units; a drive source; a sun gear connected to the drive source; a planetary gear engaging the sun gear for transmitting a drive force to one of the medium transportation units according to a rotational direction of the sun gear; and a rotational load member for applying a rotational load to the planetary gear. The rotational load member is disposed on an outer side relative to a rotational shaft of the planetary gear in a radial direction of a rotational shaft of the sun gear.

Abstract: A developer reservoir is detachably attached to an image forming apparatus and holds developer discharged from a developer discharging section of the image forming apparatus. The developer reservoir includes a developer inlet, a developer chamber, and a transport mechanism. The developer inlet receives the developer discharged from the developer discharging section. The developer chamber holds the developer delivered through the developer inlet. The transport mechanism takes the form of a screw conveyor that transports the developer from the developer inlet into the developer chamber. The developer-transporting member serves as a partition that divides the waste toner reservoir into the toner inlet and the toner chamber so that the developer is prevented from moving straight from the developer inlet into the developer chamber.

Abstract: A developer reservoir is detachably attached to an image forming apparatus and holds developer discharged from a developer discharging section of the image forming apparatus. The developer reservoir includes a developer inlet, a developer chamber, and a transport mechanism. The developer inlet receives the developer discharged from the developer discharging section. The developer chamber holds the developer delivered through the developer inlet. The transport mechanism takes the form of a screw conveyor that transports the developer from the developer inlet into the developer chamber. The developer-transporting member serves as a partition that divides the waste toner reservoir into the toner inlet and the toner chamber so that the developer is prevented from moving straight from the developer inlet into the developer chamber.

Abstract: A belt-driving apparatus has a belt in the shape of an endless loop. The belt has an outside surface and inside surface, and a guide belt that is formed on the inside surface. The belt is entrained about a roller with the inside surface in contact with the roller. A pulley is mounted at least on one axial end of the roller, the pulley having a circumferential groove formed therein that receives the guide belt therein. A resilient member that urges the first surface of the belt in such a direction that the guide belt enters the groove. The roller may have a circumferential groove formed therein to receive the guide belt, thereby eliminating the pulley.

Abstract: A belt unit is attached to an apparatus. The belt unit includes a drive roller and an idle roller about which a belt is entrained and runs, and a first bearing fitted to a shaft about which the drive roller rotates. The apparatus includes a cutout that receives the first bearing, and a locking member that engages the bearing to firmly hold the first bearing in position. A line passing through the centers of the first and second gears makes an angle with a vertical line passing through the center of the first gear, the angle being larger than a pressure angle between the first gear and the second gear. The apparatus has a groove that extends in a direction parallel to the direction of travel of the belt and receives the bearing of the idle roller.

Abstract: A belt-driving apparatus has a belt in the shape of an endless loop. The belt has an outside surface and inside surface, and a guide belt that is formed on the inside surface. The belt is entrained about a roller with the inside surface in contact with the roller. A pulley is mounted at least on one axial end of the roller, the pulley having a circumferential groove formed therein that receives the guide belt therein. A resilient member that urges the first surface of the belt in such a direction that the guide belt enters the groove. The roller may have a circumferential groove formed therein to receive the guide belt, thereby eliminating the pulley.

Abstract: A belt unit is attached to an apparatus. The belt unit includes a drive roller and an idle roller about which a belt is entrained and runs, and a first bearing fitted to a shaft about which the drive roller rotates. The apparatus includes a cutout that receives the first bearing, and a locking member that engages the bearing to firmly hold the first bearing in position. A line passing through the centers of the first and second gears makes an angle with a vertical line passing through the center of the first gear, the angle being larger than a pressure angle between the first gear and the second gear. The apparatus has a groove that extends in a direction parallel to the direction of travel of the belt and receives the bearing of the idle roller.

Abstract: An image-forming apparatus comprises a stationary main body, a lid assembly, an exposing unit, and a guide mechanism. The stationary main body accommodates a print process cartridge therein. The main body has an opening that opens upward of the image-forming apparatus. The lid assembly is rotatably supported on the stationary main body so that the lid assembly is rotatable about an axis to open and close the opening. The exposing unit is mounted to an inner side of the lid assembly and extends parallel to the axis. The exposing assembly moves into mating engagement with the print process cartridge when the lid assembly has completely closed the opening. The guide mechanism guides the exposing unit into mating engagement with the print process cartridge when the lid assembly is rotated to close the stationary main body.

Abstract: A toner cartridge includes a hollow outer body, hollow inner body, and partition. The inner body is inserted into an outer body and slidably rotatable relative to the outer body. A partition is supported in the outer body and is slidable relative to the outer body in a longitudinal direction of the cartridge. The partition is at a first position substantially adjacent a longitudinal end when the inner body is at a closing position. The partition is moved to a second position after the inner body has been rotated to the opening position, thereby defining a residual toner accommodating space between the partition and the longitudinal end of the outer body. An agitating member may be provided in which a residual toner accommodating space is formed therein. The residual toner removed from a photoconductive drum is collected in a first toner receiving section. The residual toner is then carried by a screw conveyor to one side of the print process cartridge.

Abstract: A paper feeding mechanism holds a stack of print paper in pressure contact with a paper pick-up roller. The paper pick-up roller feeds the print paper out of the tray one page at a time when the paper pick-up roller is rotated. The paper feeding mechanism has first and second supporting surfaces. The first supporting surface holds the stack of print paper from behind a back surface of the print paper. The first supporting surface is at a second angle .theta. 2 with the horizontal direction such that the print paper slides along the first supporting surface to the second supporting surface with the aid of the gravity of the print paper. The second supporting surface supports the stack of print paper thereon. The second supporting surface is inclined at a first angle .theta. 1 with a horizontal direction such that a leading edge of each page of the print paper abuts the second supporting surface and slides toward the rotating paper pick-up roller with the aid of a gravity of the print paper.

Abstract: When the surface temperature of a heating roller exceeds a predetermined temperature, bearings that rotatably support the heating roller melt. Thus, a pressuring roller causes the heating roller to move toward a temperature detecting device. Thus, the heating roller comes in contact with the temperature detecting device. Consequently, when a defect takes place, the warm-up time after the temperature detecting device works until the power to the heater is shut off can be reduced. In addition or in the alternative, an electrode plate has edges electrically contacting and connecting the heater in the heating roller and a power supply. As the heating roller moves, electrical contact between the heater and the electrode plate is broken and the power from the power supply to the heater is disconnected. As a result, an electrophotographic printing apparatus can be prevented from getting defective, thereby improving the reliability thereof.