Ricoh Company, Ltd.

Katsuhiko Miki

Hiroshi Kajiyama

Yoshikuni Ishikawa

Masaru Yamagishi

Nobuo Inoue

Tadashi Kusumi

Yuko Hayama

Osamu Takehira

Masanori Matsuda

Yasuharu Gaman

Kouki Sakamoto

Nobuyuki Shimodaira

Takashi Koshinuma

An attachment assist device includes an engagement member provided in one of a main body and a retractable unit, a catch portion provided in the other of the two, to engage the engagement member when the retractable unit is positioned at a drawing start position, and a drawing unit provided in the main body, to draw the retractable unit to a drawing completion position in the main body against multiple resistive forces acting on the retractable unit. On a projection plane on which the retractable unit is projected in an attachment direction, an engagement position where the engagement member engages the catch portion is disposed inside a rectangular area defined by two opposing corners respectively positioned at points of action of two of the multiple resistive forces acting on the retractable unit while the retractable unit moves from the drawing start position to the drawing completion position.

Attachment assist device and image forming apparatus including same

An assist mechanism aids movement of a retractable unit reciprocally moving between an open and a closed position and includes a pressing device, a stopper mechanism, an engagement member, a catch portion, and a release member. The pressing device presses the retractable unit toward the open position in which the unit is extended. The stopper mechanism controls and releases retraction of the retractable unit to the closed position in which the unit is retracted, and includes a stopper and a blocking member. The engagement member is provided in the retractable unit. The catch portion engages the engagement member. The release member releases a force pulling the retractable unit when the retractable unit is moved to the closed position.

Assist mechanism and image forming apparatus

An attachment assist device includes an engaging member, an engaged member, a drawing-force generator, biasing members, and rotational members. The engaging member is provided at one of a main unit and a sub unit detachably attached to the main unit. The engaged member is engaged by the engaging member and provided at the other of the main unit and the sub unit. The drawing-force generator generates a drawing force to draw the sub unit into an interior of the main unit. The biasing members are provided at the drawing-force generator to generate biasing forces in different directions. The rotational members are provided rotatably around support points at the drawing-force generator and engaged with the biasing members. The biasing members are serially connected with the rotational members to convert the biasing forces of the biasing members to the drawing force.

Attachment assist device and image forming apparatus employing the attachment assist device

A sheet conveying apparatus, an automatic draft conveying apparatus, a paper feeding apparatus, and an image forming apparatus capable of preventing self-oscillation of a conveying roller. When rigidity of an oscillation system of the conveying roller is K [N/m], the distance between a supporting point of an arm and a section of the arm to which an axis of the conveying roller is attached is L [mm], and arm angle, which is formed between a sheet and a line segment connecting the supporting point of the arm to the section of the arm to which the axis of the conveying roller is attached on an assumed plane perpendicular to a direction of the axis of the conveying roller, is &#x3b8; [deg], &#x3b8;&#x2266;(Pse&#xd7;K)&#xd7;(1/L) is satisfied, where Pse=37500.

Image forming apparatus

A medium discrimination device includes a transmitted light quantity measurement device arranged to measure a transmitted light quantity in a thickness direction of a printing medium on a conveyance route, and configured to perform a measurement of the transmitted light quantity at each time the printing medium is conveyed, a measurement value memory device storing a result of the measurement performed by the transmitted light quantity measurement device, a medium setting device configured to previously set a type of printing medium to be used, a medium information memory device storing information of a transmitted light quantity assigned to each printing medium to be set by the medium setting device, and a control processing unit configured to perform paper type detection on a first printing medium, and double feed detection on following printing mediums.

Medium discrimination device, image forming apparatus, and program having simplified mechanism

A detector detects a size of a recording medium stored in a tray of a device. The tray includes a first regulating member that can slide in a width direction of the recording medium, and a second regulating member that can slide in a feed direction of the recording medium. A first movable member engages with the first regulating member, and a second movable member, overlapped by the first movable member, engages with the second regulating member. Both the first and second movable members rotate around a common pivot and include convex members on peripheral edges thereof. Switches are selectively pressed by the convex members when the tray is attached to the device.

Paper feed tray, paper feeding apparatus, and image forming apparatus using movable members to move aligning units and lock in place

A paper feed cassette capable of detecting the size of the recording medium loaded on the paper feed cassette, and an image formation device comprising this recording medium size detector. Side fences and an end fence are slidably provided to a cassette body detachably installed in the body case, and a first movable member which moves in synchronization with the sliding motion of the side fences, and a second movable member which moves in synchronization with the sliding motion of the end fence are provided to the cassette body in an overlapping state. A plurality of synthesized convex portions are formed by overlapping a plurality of first convex portions formed on the first movable member and a plurality of second convex portions formed on the second movable member, and, by sliding the side fences and the end fence in accordance with the size of the recording medium loaded on the cassette body, the width size and position of the synthesized convex portions change in accordance with the size of the recording medium loaded on the cassette body.

Paper feed cassette, recording medium size detector and image formation device using coaxial movable members for moving orthogonal fences

A method of feeding sheets includes the step of conveying the sheets between a feed roller and a separation member. The separation member is pressed against and into contact with the feed roller with a pressure applied between the feed roller and the separation member. The method also includes the steps of separating and conveying the sheets conveyed between the feed roller and the separation member one by one, and providing a cyclic change in the pressure between the feed roller and the separation member.

Sheet feeding method and device and image forming apparatus using the device

A paper feeder includes a plurality of paper feeding units that feeds a recording medium from a paper feeding tray, has a first guiding surface towards a paper transporting path that guides the recording medium, and is arranged along a direction of transporting the recording medium, and a transporting guide that has a second guiding surface towards the paper transporting path between the paper feeding units. The transporting guide is arranged in such a manner that the second guiding surface is overlapped with the first guiding surface of at least one of the paper feeding units adjacent to the transporting guide on either of an upstream side and a downstream side in the direction of transporting the recording medium.

Paper feeder and image forming apparatus

The sheet feeding apparatus feeds sheet media between a feed roller and a separating member pressed into contact with the feed roller, and separates and conveys sheet media held between the feed roller and the separating member one by one by utilizing differences in frictional coefficients between the feed roller, the separating member, and the sheet media. The sheet media are separated and conveyed while periodically changing the pressurizing force of the reverse roller against the feed roller.

Method of and apparatus for feeding sheets, image formation apparatus, and method of manufacturing gears

A sheet feeding device including a sheet tray accommodating stacked sheets, and a sheet feeding unit feeding the stacked sheets in the sheet tray one by one. The sheet feeding unit includes a feeding roller which rotates in a sheet feeding direction, and a separation roller which presses against the feeding roller when feeding each of the stacked sheets and which rotates, via a torque limiter, in a direction opposite the sheet feeding direction. The separation roller is rotated by rotation of the feeding roller when a single sheet is sandwiched between the feeding and separation rollers. Also included is a conveying member arranged downstream of the feeding roller in the sheet feeding direction, and a driving source which drives each of the feeding roller, the separation roller, and the conveying member via a driving force transmission mechanism so the separation roller and the conveying member are driven in conjunction with each other.

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

A paper feeder for use in an image forming apparatus is disclosed. The paper feeder applies vibration to paper sheets being paid out together to thereby reduce an adhering force acting between them. The paper feeder therefore reduces the simultaneous feed of two or more papers to a noticeable degree. An image forming apparatus including the paper feeder is also disclosed.

Feeder with vibrating separating device

A paper feeding mechanism and method which reliably feeds individual sheets stacked on a base plate. When a full stack of sheets resides on the base plate, as the sheets are removed one-by-one from the top of the stack, the base plate pivots about an end of the base plate. After the base plate pivots to a predetermined level, a pin passing through an oblong hole in a side support connected to the base plate contacts an end of the oblong hole and changes the pivot position of the base plate to the position of the pin. Also, a separating claw is raised as the sheets are removed from the stack. As the sheets from the stack are removed, the base plate supporting the sheets is raised. The raising of the base plate causes the rotation of a cam member. As the cam member rotates, the changing cam surface which contacts a separating member connected to the separating claw causes the separating claw to be raised.

Paper feeding mechanism to feed individual sheets from a tray or cassette

A sheet feeding device for an image forming apparatus of the present invention includes a sheet sustaining portion for sustaining a stack of sheets loaded on a bottom plate. Even when a great number of sheets are stacked on the bottom plate, the sustaining portion reduces a load to act on the bottom plate and thereby prevents the bottom plate and sheets from warping or sinking. This allows a pick-up roller to press the sheet stack with an adequate force and feed the sheets stably one by one.

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Tokyo, Japan

Katsuhiko Miki