Ricoh Company, Ltd.

Yamauchi Corporation

Toshifumi Togashi

Manabu Nonaka

Hideto Higaki

Tsugunao Toyooka

Osamu Takehira

Eiichi Hattori

A sheet separating and feeding unit incorporable in an image forming apparatus includes an image forming device, a sheet container, a sheet feeding unit including an endless, dielectric belt and an electric potential pattern forming unit, a belt supporting mechanism including a first supporting roller and a second supporting roller, and a moving unit. The first supporting roller rotates to rotatably move the second supporting roller between a sheet attracting position and a sheet feeding position so that the flat portion of the dielectric belt moves between the sheet contact position and the sheet pick-up position.

Image forming apparatus

A sheet feeding device incorporable in an image forming apparatus includes a sheet holder to hold a stack of sheets including an uppermost sheet, an endless belt, a charging member, a belt supporting unit including a drive roller and a driven roller, a moving mechanism to move the sheet holder, and a controller. The controller alternately controls the moving mechanism to move the sheet holder to a proximal position, the endless belt to contact the uppermost sheet held on the sheet holder, and the driven roller to rotate about the drive roller, to attract the uppermost sheet, and controls the moving mechanism to move the sheet holder to a distal position, the driven roller to rotate about the drive roller, and the endless belt to incline at a predetermined angle of separation, to separate the uppermost sheet from the multiple sheets.

Sheet feeding device and electrophotographic image forming apparatus with rotating charged belt

In a sheet separator of a sheet supplier, a friction separator and an electrostatic separator separate an uppermost sheet from other sheets of a plurality of sheets loaded on a sheet tray by a friction force and an attraction force generated by a non-uniform electric field, respectively. A conveyance member is provided downstream from the friction separator and the electrostatic separator in a sheet conveyance direction to feed the uppermost sheet separated by at least one of the friction separator and the electrostatic separator in the sheet conveyance direction. The friction separator and the electrostatic separator are arranged in such a manner that planes of projection of the friction separator and the electrostatic separator overlap or coincide in a direction perpendicular to the sheet conveyance direction in which the conveyance member feeds the uppermost sheet.

Sheet supplier and image forming apparatus incorporating same with friction and electrostatic separators with overlapping planes of projection

An image forming apparatus is disclosed that includes an image forming part configured to form an image on a recording medium, a feed part for feeding the recording medium, a manual feed part for manually feeding the recording medium, and a shutter member configured to open and close a manual feed opening from the manual feed part. The shutter member is provided so as to be swingable.

A sheet feeding device comprises a sheet feeding member having an outer layer thereof, a sheet loaded on a sheet loading member being depressed on a peripheral surface of the outer layer, the sheet feeding member delivering the sheet depressed to the peripheral surface, through rotation of the peripheral surface. An inclination member having a depression portion and an inclined surface, the depression portion depressing the sheet on the peripheral surface, and a leading edge of the sheet being brought in contact with the inclined surface. The outer layer of the sheet feeding member is formed of a cross-linked rubber material which has a JIS-A hardness in a range between 25 degrees and 40 degrees, a tearing strength measured with a JIS B-type specimen, which is 10 N/mm or more, and a viscoelastic characteristic expressed by a loss tangent, which is 0.045 or less.

Sheet feeding device and image forming apparatus comprising the sheet feeding device

A method for feeding sheet materials is disclosed, which is implemented by forwarding a plurality of sheet materials loaded on a loading plate with a rotating feeding roller toward a separation unit, for the leading edge of the sheet materials to be collided with a tapered face of taper member, and subsequently separating the uppermost of the loaded sheet materials through frictional force from the feeding roller after climbing over the taper member to be forwarded further to an image forming unit by way of a nip forming portion, while other underlying sheet materials are halted by the taper member owning to smaller frictional forces there between, thereby obviating the multiple feeding. In addition, the conditions suitable for sheet feeding can be satisfied for various sheet materials different in size and thickness by adjusting the distance between the point of contact of the uppermost sheet material with the feeding roller and that of nip formation, such that modulus values are equated to various sheet materials. As a result, considerably high sheet separation qualities are obtained obviating undue non-feeding or multiple feeding, and various kinds of sheet materials different in size, thickness and coefficient of friction, can be forwarded sheet by sheet securely to image forming unit, thereby achieving satisfactory image formation by means of image forming apparatuses incorporating the sheet feeding apparatuses disclosed herein.

Method and apparatus for sheet feeding and image forming apparatus incorporating the same

A sheet feeder separates a stack of sheet materials one by one for securely feeding individual sheet materials without multiple sheet feeding or failure in feeding a sheet material. The leading edge of a sheet material stacked on a bottom board of a cassette is brought into contact with a sheet feed roller. Near the location at which the leading edge of the sheet material comes in contact with the sheet feed roller, a tilt member is pressed onto the sheet feed roller by the action of a compression spring. A contact area of the tilt member with the sheet feed roller is reduced to prevent the sheet feed roller from rotating together with the sheet material. The topmost sheet material is fed by the rotation of the sheet feed roller in the counter-clockwise direction and supplied beyond the tilt member by friction with the sheet feed roller, whereas the next sheet material is blocked by the tilt member due to less friction between the sheet materials, thereby preventing multiple sheet feeding.

Growing community of inventors

Zama, Japan

Toshifumi Togashi