Sharp Kabushiki Kaisha Corporation

Kohji Aoki

Haruhisa Furumoto

Yoshiyuki Kobayashi

Masaharu Kimura

Norichika Katsura

Yasuhiro Takai

Yoshinobu Tateishi

Atsushi Ide

Yasuaki Fukada

Hiroaki Hori

Toyoaki Nanba

Masahiko Fujita

Toshiya Mikita

Motoaki Okitsu

Yoshinori Shiraishi

Yoshiteru Kikuchi

Tatsuya Shinkawa

Shinichi Azumi

Noriko Inoue

Tsuyoshi Shibayama

Hideki Goto

Tadashi Noguchi

Kohichi Moriyama

A sheet feeding device includes a sheet feeding cassette, which is detachable with respect to a sheet feeding cassette mounting portion provided on an image forming device body. The sheet feeding cassette includes a storage portion that stores a paper sheet, a first regulator provided on a bottom portion of the storage portion that regulates the position of a paper sheet, and a movable placement plate that upwardly pushes a paper sheet stored in the storage portion. The movable placement plate includes a second regulator that regulates the position of a paper sheet having a different size to the size of a paper sheet that can be regulated by the first regulator.

Sheet feeding device and image forming device

A sheet accommodating device includes a first plate member on which sheets are mounted, a first biasing member, a second plate member; and a second biasing member, and has a configuration in which, according to a size of the sheets, the first biasing member presses up the first plate member or both the first and second biasing members press up both the first and second plate members. The first plate member is provided so as to be turnable with respect to the second plate member around a first fulcrum axis line extending along a width direction orthogonal to a sheet feed direction in which the sheets are fed. The second plate member is provided so as to be turnable with respect to a body of the sheet accommodating device around a second fulcrum axis line extending along the width direction.

Sheet accommodating device and image forming apparatus including the same

A sheet accommodating device includes a regulating member that regulates end portions of sheets and a moving member movably provided in a body of the sheet accommodating device. The regulating member is detachably provided on the moving member. A moving region of the moving member includes a size regulation region where the end portions of the sheets are regulated and a predetermined non-size regulation region excluding the size regulation region. The sheet accommodating device is configured to permit the regulating member to be attached to and detached from the moving member in a predetermined attaching and detaching position of the non-size regulation region and prohibit the regulating member from being detached from the moving member in a detachment prohibition region of the moving region excluding the attaching and detaching position.

A sheet accommodating device includes a first plate member on which sheets are mounted, a first biasing member that presses up the first plate member, a second plate member disposed on a side of the first plate member opposite to a side of the first plate member on which the sheets are mounted; and a second biasing member that presses up the second plate member, and has a configuration in which, according to a size of the sheets, the first biasing member presses up the first plate member or both the first and second biasing members press up both the first and second plate members. An area of the first plate member is smaller than an area of the second plate member.

An image forming apparatus () includes a discharge section (), a paper receiving tray (), a first detecting section (), a lever (), a second detecting section () and a decision section (). The first detecting section () is disposed in the discharge section (), and detects a paper jam. The second detecting section () detects a swinging state of the lever () from a first position at which the lever () is not in the process of receiving an action of the paper sheet to a second position. The decision section () judges an occurrence factor in a paper jam to be a user-induced factor when the second detecting section () detects a state in which the lever is at the first position in a state where the first detecting section () detects the paper jam. Also, the decision section () judges the occurrence factor in the paper jam to be an image forming apparatus-induced factor when the second detecting section () detects a state in which the lever is swung over the first position in the state where the first detecting section detects the paper jam.

Image forming apparatus that determines user-induced paper jam

A paper conveying device includes: a registration roller pair provided along a paper conveying path; a pick-up roller, a paper feed roller and a separation roller for feeding sheets of paper to the paper conveying path; and a controller controlling conveyance of sheets of paper such that when a preceding sheet is stopped at the registration roller pair, a following, succeeding sheet is temporarily stopped at a prescribed position G downstream of a conveying roller in the paper conveying direction, and the succeeding sheet is re-conveyed toward the registration roller pair at a prescribed timing. The controller changes the timing to start re-conveyance of the succeeding sheet in accordance with paper length of the conveyed sheet of paper.

Paper conveying device, image forming apparatus provided with the device and paper conveying method

A paper feeding device includes a pressing member, a restricting mechanism, and an interlocking mechanism. The pressing member is movable up and down between a pressing position and a release position. The pressing position causes a pressure to a paper sheet against the feed roller. The release position causes a release of the pressure. The restricting mechanism is movable between a restricting position and a removal position. The restricting position causes a restriction on moving up of the pressing member to the pressing position. The removal position causes a removal of the restriction. The interlocking mechanism is configured to move the restricting mechanism to the removal position in interlock with rotation of the feed roller.

Paper feeding device and image forming apparatus

A sheet conveying device () includes a plurality of first conveyance rollers () and a plurality of second conveyance rollers (). The sheet conveying device () includes stiffening rollers (). The stiffening rollers () are disposed coaxially with at least one conveyance rollers () among the first and second conveyance rollers () and (), and have diameters larger than diameters of the conveyance rollers (). The stiffening rollers () includes first stiffening rollers (), which apply conveying forces to a sheet (P), and second stiffening rollers (), which apply smaller conveying forces to the sheet (P) than the conveying forces to the sheet (P) in the first stiffening rollers ().

Sheet conveying device and image forming apparatus with the same

A recording paper conveying device includes a registration roller pair and a conveyor roller pair adjacent to the registration roller pair. By rotating the conveyor roller pair, a sheet of recording paper is fed until leading edge of the sheet abuts the registration roller pair in stationary state so that the sheet is deflected by a prescribed amount. Then, conveyor roller pair is rotated at the constant velocity, and while the sheet is kept deflected, rotation of the registration roller pair is started, to start feeding of the sheet by the registration roller pair. While the registration roller pair is kept rotating, rotation of the conveyor roller pair is suspended, and then, the conveyor roller pair is returned to the state of rotation before suspension. Thus, unnecessary deflection of the sheet just in front of the registration roller pair can be prevented.

Recording paper conveying device, document feeding device and image forming apparatus including these devices

A sheet transport apparatus includes a sheet transport portion that transports a sheet in a first transport direction and a second transport direction, a bending member that bends without breaking the sheet by corrugating the sheet in an orthogonal direction, and a restriction member that restricts, in a perpendicular direction, a corrugation in the sheet bent by the bending member. The restriction member is provided on an upstream side in the first transport direction of the bending member.

Sheet transport apparatus and image forming apparatus including the same

A conveying device includes a switching gate, a handle, and a link mechanism. The switching gate switches the direction in which a sheet of paper is conveyed along a conveying path. Normally, the weight of the switching gate keeps a front end portion of the gate engaging with a recess. A user grips the handle when he/she opens the conveying device from an apparatus. The user's grip on the handle makes the link mechanism disengage the gate portion from the recess. The link mechanism includes a protrusion protruding toward the apparatus and having a slope, which tapers off. When the conveying device closes into the apparatus, compressive contact of the protrusion slope with a wall of the apparatus disengages the gate portion from the recess.

Conveying device

A fixing apparatus and an image forming apparatus of the present invention are arranged so that a fixing control section causes a fixing roller to additionally rotate so that the additional rotation corresponds to a driving delay time also after turning OFF an external heating roller heater when shifting from a temperature raising step in which surface temperature of the fixing roller is raised so as to be equal to a preset fixing temperature to a standby mode and when turning OFF the external heating roller heater and stopping the fixing roller. As a result, it is possible to provide a fixing apparatus and an image forming apparatus in which a surface of a fixing roller is free from deterioration or breakage caused by local heating carried out by an external heating roller.

Fixing apparatus and image forming apparatus including the same

The fixing device includes a pair of rotating bodies which conveys a recording medium between a nip; a heating unit which heats at least one of the rotating bodies; and a temperature detection unit which detects a temperature of at least one of the rotating bodies. The temperature detection unit detects a temperature change until an image forming apparatus is normally operated since the heating unit starts the heating, and the temperature change is stored. It is judged that the image forming apparatus is in an abnormal state when the temperature detection unit detects a temperature change different from the temperature change in the normal operation. A temperature control unit stops passage of current through the heating unit when it is judged that the image forming apparatus is in the abnormal state.

Fixing device

In a fixing apparatus of the present invention, an end section fixing control temperature changing section selects an end section fixing control temperature in accordance with the number of paper sheets that have been processed in one continuous printing process. A sub-heater on/off determining section turns on or off a sub-heater in accordance with a temperature detected by an end section temperature sensor and the end section fixing control temperature selected by the end section fixing control temperature changing section. This prevents the occurrence of fixing failure even in continuous printing with respect to large-size paper sheets in an arrangement in which a temperature sensor is disposed outside a maximum-size sheet passing region at an end section of a fixing roller and controls energization of a heater which is disposed corresponding to the end section of the fixing roller in accordance with a temperature detected by the temperature sensor.

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Osaka, Japan

Kohji Aoki