Ricoh Company, Ltd.

Ricoh Systems, Inc.

Ricoh Corporation

Carl P Anderson

Edward F Mayer

Edward E Mayer

In an electrophotographic copying apparatus, the document stack to be fed is curved when it rests on a fixed curved stack-holding tray. The document stack is lifted by a pair of lifting blades having the curvature of the stack which move horizontally relative to the ends of the stack to move in and out beneath the sides of the stack, and thereafter move vertically to lift the entire stack out of the path of the returning copy. A vacuum belt arrangement is provided for moving successive documents from the top of the stack into the electrophotographic copying machine. The document loops through the machine and returns at a lower level, aligned with an opening beneath the bottom of the stack. Moving belts running beneath the stack carry the returning document into alignment under the stack. Once the document is returned, the lifting blades move vertically downward and laterally outward, resting the remainder of the document stack on the returned document, making it a part of the stack; when the lifting blades again perform their cyclic motion, they again move under the bottom edges of the stack and lift the stack, including the returned document. The blades are carried on vertical side supports. When a sheet is being returned to the stack, at least one vertical lifting blade side support is held a short distance from the side of the stack. When the stack is to be lowered, the vertical support is first moved in toward the stack so that the bottom, returned sheet is aligned with the rest of the stack. The stack is then lowered onto the returned sheet. Knife edge elements are provided movable between the belts which return the sheets to the bottom of the stack. These knife edges are normally lowered; they rise between the belts to lift the returned sheet up under the bottom of the stack.

Recirculating automatic document feeder

A sheet feeder is disclosed having a cartridge mounted adjacent the stack of paper providing an exposed line of adhesive strip. The adhesive should be a temporary adhesive which when removed leaves no residue or damage on the sheet to which it was temporarily bonded. The cartridge is landed on the top sheet of paper adjacent the leading edge of the sheet, and the cartridge is then rotated away from the direction in which the sheet is to be fed while maintaining a minimum amount of pressure on the top of the stack. This effectively bonds the gummed strip on the cartridge to the edge of the top sheet of paper; and the motion away from the feeding direction lifts the top edge of the sheet from the edge of the sheet below, which now forms the top of the stack. The sheet below, also to be called the second sheet, remains in place because of the combination of downward pressure against the second sheet near its leading edge created by the cartridge, together with the beam strength of the paper which tends to cause the sheet to continue to lie flat. The cartridge can now be moved in the feeding direction, presenting the sheet of paper to an entry path to the copying machine.

Electrophotographic copying apparatus incorporating an automatic

A document feeder is disclosed wherein a document stack is bent or curved when it rests on a fixed curved stackholding tray. A stack of paper becomes rigid when curved, and therefore, capable of being raised by applying an upward force along the curved edge on each end of the stack provided by a pair of curved lifting blades which move horizontally relative to the ends of the stack to move in and out underneath the edges of the stack, and thereafter move vertically to lift the entire stack out of the path of the returning copy. The document to be copied may be lifted off the top of the document stack either before or after the lifting action of the blades. A vacuum belt type arrangement is provided for moving successive documents from the top of the stack. The document loops through the machine, and returns at a lower level, aligned with an opening beneath the bottom of the stack. A levered plate is provided at the trailing lateral edge of the stack to be sure that the edges of the stack are lifted out of the return paper document path. Moving the belts running beneath the stack carry the returning document into alignment under the stacks; a metal plate running horizontally or laterally along the edge of the stack perpendicular and very close to the belts acts as a stop to stop the returning document in alignment with the document stack being fed. Once the document is returned, the lifting blades move vertically downward, and laterally outward, resting the remainder of the document stack on the returned document and making it a part of the stack.

A copying device having an automatic document feed has a bar which extends across a substantial portion of the document path out of alignment with the image scanning portion of the platen. This bar is of a magnetically receptive material so that it is responsive to movement of a magnet which is located on the opposite side of the document-moving belt. When a document is being moved by the belt into the document exposing region, the document stop bar rests on the platen or at the edge of the platen so that the leading edge of the document butts against it. When the document is to be ejected, the magnet is moved, raising the document stop bar out of the document path; a roller which is adjacent the belt and the document being copied can now be rotated and eject the document below the document stop. In addition to lifting the magnet and therefore the document stop bar, the magnet moves slightly forward along the document path so that the edge of the document is removed from the document stop bar. In this way, the document does not bind against the stop bar and the document may be easily ejected.

Automatic platen document stop for electrophotographic copying apparatus

A self tracking web drive is provided wherein the roller with the friction drive in the center decouples all but a very limited width portion of the belt from the roller. By doing this, the flanges on a second roller cause the belt creep direction to reverse relative to the central high friction drive and move in the opposite direction. Depending on the alignment of the roller axes, the belt will either walk slowly to one side, then to the other, or to walk to one side, retreat and gradually self-adjust to track close to the flange or just off it. In fact, a thin driving high-friction area on one roll reduces the contact width between roller and belt and thereby tricks the wide belt into acting as if the width to pulley spacing was 10:1 or greater and becoming self tracking.

Wide belt tracking method and apparatus

A bottom feeder for copy paper feeding has means for imparting a curvature to the sheets, the curvature being in the direction the sheets will be withdrawn. The curvature provides transverse rigidity to permit lifting weight of stack off the bottom sheet. This facilitates withdrawing the sheets one at a time from the bottom of the stack. A curved paper tray imparts a curvature to the paper. A pair of holding clamps are provided, one on either side of the stack of paper, which are partially withdrawn from the sides of the paper stack so that paper may be added to the stack. When sheets are to be fed, the clamps which comprise a pair of plates having a friction material on the paper facing side thereof are moved in to engage the sides of the stack of paper. An arrangement is provided to thereafter lower the paper tray slightly from the bottom of the stack, or lift the clamps and the curved paper stack. In either event, the pressure of the stack weight is now removed from the bottom sheet. A vacuum type feed belt which passes under the stack of paper can now pick off one sheet at a time without the sheets being restrained by friction against the paper tray or created between the tray and the stack of paper. The friction material on the holding plates in a preferred embodiment comprises bristles angled upward away from the paper tray to retain the stack lifted from the paper tray while allowing relatively easy withdrawal of each sheet. A stack-height sensor, preferably a switch on the face of one of the plates, senses the condition where, as the height of the stack diminishes, the pressure of the holding clamp plates may be slightly reduced to avoid binding of the paper. Timing means, which in the disclosed embodiment comprise cams riding on a common shaft, are provided to coordinate the movement of the clamps toward and away from the sides of the stack with the movement of the paper tray away from the bottom of the stack of paper.

Copying apparatus with automatic bottom feeder

An electrophotographic copying apparatus has an electrically charged toner of one polarity which is transformed from an oppositely electrically charged surface of a photoconductive drum to the front side of a blank sheet where the front side of the blank sheet is intended to be a copy. The back side of the blank sheet engages the outer surface of a transfer drum which is positioned adjacent to the photoconductive drum. The transfer of the toner occurs within a nip defined by the photoconductive drum and the transfer drum. A cam rotates in a timed sequence relative to the transfer drum and with a vacuum pump located adjacent to the transfer drum the cam is in communication with the surface of the transfer drum so that a vacuum is created at the back side of the blank sheet resulting in the blank sheet being held to the surface of the transfer drum by ambient air pressure and the vacuum thus overcoming the electrostatic attraction of the blank sheet to the photoconductive drum.

Electrophotographic copying apparatus including transfer hold-down pump

An electrophotographic copying apparatus designed to make successive copies from a stack of original documents, automatically, is disclosed herein. To this end, the apparatus utilizes a feeding arrangement configured to act on the stack in a way which successively moves each document onto the copying platen from the bottom of the stack when the latter is placed in a feed tray forming part of the overall arrangement, and thereafter back onto the top of the stack within the tray along a looped path of movement from the tray to the platen and back to the tray. The copying apparatus also includes an assembly located to one side of the feed tray for detecting when the last document in the stack has moved from the tray to the copying platen.

Electrophotographic copying apparatus having an automatic feed

A document-feeding apparatus including feed rollers 90, pressure roller 50, a planar tray 16 for receiving a stack of sheet material and having one end portion 94 thereof deformed arcuately away from the main plane of the tray, the arcuate segment 94 being provided with openings 98 through which a sheet separating vacuum may be drawn, and longitudinally extending slots 96 through which the paper-engaging surfaces of the continuously running feed rollers 90 extend, an oscillatory vacuum pumping mechanism 92 for periodically drawing air through the vacuum openings so as to deflect the overlying end portion of the bottom sheet of the stack of material downwardly into engagement with the feed rollers 90 after which the pressure rollers 50 are moved into engagement with the upper surface of the deflected bottom sheet to hold it against the feed rollers 92 as it is driven thereby toward a pair of exit rollers 84 and 86 which thereafter discharge the sheet from the device.

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Menlo Park, CA, United States of America

Carl P Anderson