Abstract: A driving apparatus transmits a driving force from a drive source to a driven body via a multiple-stage gear train (including, for example, gears). In the multiple-stage gear train, the speed fluctuation phase of a mesh frequency occurring at each mesh point of the gear train including the gears to a target gear is set in a range in which the speed fluctuation amplitude of the target gear positioned downstream at the third stage or later is equal to or less than the speed fluctuation amplitude of the immediately preceding mesh gear positioned upstream. The invention also applies to an image formation apparatus using the drive as a drive of a driven body.

Abstract: A driving apparatus transmits a driving force from a drive source to a driven body via a multiple-stage gear train (including, for example, gears). In the multiple-stage gear train, the speed fluctuation phase of a mesh frequency occurring at each mesh point of the gear train including the gears to a target gear is set in a range in which the speed fluctuation amplitude of the target gear positioned downstream at the third stage or later is equal to or less than the speed fluctuation amplitude of the immediately preceding mesh gear positioned upstream. The invention also applies to an image formation apparatus using the drive as a drive of a driven body.

Abstract: A drive apparatus is comprised of a driven shift of a rotary photosensitive drum, a drive motor and a gear mechanism for rotatably driving the driven shaft, and a flywheel rotated around a wheel rotary shaft, for stabilizing the rotations of the driven shaft. A pulley having a large diameter is mounted on a rotary shaft directly coupled to the driven shaft, whereas a pulley having a small diameter is mounted on the wheel rotary shaft. An endless belt is wound on these pulleys, so that drive force is transferred from the rotary shaft to the wheel rotary shaft, and an angular velocity of the flywheel is made higher than that of the driven shaft.

Abstract: A sheet forwarding apparatus for supporting a sheet on a transfer drum in a electrophotographic copying machine, onto which a toner image on a photoreceptor drum is transferred, which apparatus includes a pressure roller for pressing the sheet onto the transfer drum while forwarding. An arm member supports the pressure roller and is pivotable around a shaft so as to cause the pressure roller to alternately contact and distance from the transfer drum. An oscillating unit is included for oscillating the arm member, and to apply a constant pressure to the sheet through the pressure roller when the pressure roller is in contact with the transfer drum.

Abstract: A sheet registering unit for an image forming apparatus in which in the location upstream of the transfer stage, a preregistering roller device and a registering roller device are disposed while being separated with a predetermined distance from each other, and the leading edge of a sheet of paper is positioned with the aid of a loop of the sheet formed in a manner that the leading edge is thrust against the nip of the paired rollers of the registering roller device, and in this state the sheet is additionally pushed by the preregistering roller pair. In the sheet registering unit, the shafts supporting the roller members of the registering roller device or the roller members are supported by the combination of linear bearing members and springs, and by a pressure in the oblique direction caused in the sheet nipped by the registering roller device, the roller members of the registering roller device are shifted in the axial direction.

Abstract: A sheet transport roller device is disclosed, comprising a drive roller member and a free roller member disposed facing each other with a specified pressure between them and transport a sheet held between them, a device which allows each roller of the drive and free roller members to move in the axial direction, urging members disposed at both ends of the rollers, in which the roller devices are moved in the direction lateral to a sheet transport path as a sheet is being held by the roller devices, in accordance with an action moving said sheet in the direction lateral to the transport path.