Abstract: 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.

Abstract: A functional unit positioning device for positioning a functional unit detachably attachable to an apparatus body, includes a biasing device that biases the functional unit in a unit-out direction; and a stopper mechanism having a first stopper and a second stopper, the stopper mechanism exerting and releasing control over release of the functional unit. The biasing device biases the functional unit by the biasing device so that the second stopper comes in contact with the first stopper to set the functional unit in a locked position in a unit in-out direction. The biasing device is also configured to change the magnitude of a bias force on the functional unit from low to high when the functional unit is inserted and advanced up to a predetermined position into the apparatus body.

Abstract: A sheet conveying device, that can be included in an image forming apparatus, includes first and second conveying units configured to hold and convey a sheet, a first sheet conveying path between the first and second conveying units, and a registration unit to change a positional condition of the sheet conveyed by the second conveying unit. In at least one embodiment, the second conveying unit includes a moving and guiding unit and a rotary conveyance unit facing each other and forming a sheet holding section therebetween to hold and convey the sheet, and the moving and guiding unit and the rotary conveyance unit are disposed in the vicinity of the first conveying unit so that a distance between the second conveying unit and the registration unit is relatively increased.

Abstract: 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.

Abstract: A sheet conveying device, that can be included in an image forming apparatus, includes a first conveying unit to convey a sheet in a first sheet conveying direction, a second conveying unit including a sheet holding section to hold and transfer the sheet in a second sheet conveying direction, a sheet conveying path provided between the first conveying unit and the second conveying unit, a belt-type sheet conveying unit including a belt and first and second rotary belt holding members, a shaft holding member to hold the first and second rotary belt holding members to be spaced at a given constant interval, and a regulation member to regulate a movement of the belt in the sheet width direction.

Abstract: A sheet conveying device, that can be included in an image forming apparatus, includes a first conveying unit to convey a sheet in a first sheet conveying direction, a second conveying unit to convey the sheet conveyed by the first conveying unit in a second sheet conveying direction that is different from the first sheet conveying direction, a first sheet conveying path provided between the first conveying unit and the second conveying unit, a belt-type sheet conveying unit to the holding section of the second conveying unit, and a positioning control mechanism to move and position the first supporting member and the second supporting member in respective directions different from each other. The belt-type sheet conveying unit includes a belt, a first rotary belt holding member, a second rotary belt holding member, a first supporting member, and a second supporting member.

Abstract: A feed device feeds a sheet of a recording medium, and includes a body, a support shaft, and a pickup mechanism. The pickup mechanism contacts and picks up the sheet, and includes a swingable arm and a pickup unit. The swingable arm is rotatably mounted on a support shaft provided in the body of the feed device, and includes a fulcrum shaft. The pickup unit is rotatably attached to the fulcrum shaft of the swingable arm, and includes an endless elastic belt, a first pulley, a supporter, and a second pulley.

Abstract: A sheet elevating apparatus for use in a sheet tray cassette detachably installable to an image forming apparatus includes an elevation driving source, a first coupling, an elevation member, a second coupling, and an elevation controller. The elevation driving source is mounted to the image forming apparatus. The first coupling is connected to the elevation driving source and has a home position. The elevation member elevates a plurality of recording sheets placed on an elevating base plate of the sheet tray cassette. The second coupling is connected to the elevation member and is engaged with the first coupling set at the home position when the sheet tray cassette is installed in the image forming apparatus. The elevation controller drives the elevation driving source to set the first coupling to the home position when the sheet tray cassette is pulled out.

Abstract: An image forming apparatus includes image forming and sheet feeding mechanisms. The sheet feeding mechanism includes a bottom plate, a first roller, a separator including second and third rollers, and a sensor. The bottom plate loads sheets. The first roller feeds an uppermost sheet of the sheets loaded on the bottom plate. The separator separates the uppermost sheet from the other sheets when a plurality of sheets are fed by the first roller. The sensor is disposed between heads of the sheets loaded on the bottom plate and the separator and detects the uppermost sheet fed by the first roller. The image forming apparatus further includes a controller for driving the first roller to feed a next uppermost sheet loaded on the bottom plate when the sensor does not detect the next uppermost sheet when a tail portion of the previous sheet passes the separator.

Abstract: A sheet conveying device, that can be included in an image forming apparatus, includes a first conveying unit to convey a sheet in a first sheet conveying direction, a second conveying unit to convey the sheet conveyed by the first conveying unit in a second sheet conveying direction that is different from the first sheet conveying direction, a first sheet conveying path provided between the first conveying unit and the second conveying unit, a belt-type sheet conveying unit to the holding section of the second conveying unit, and a positioning control mechanism to move and position the first supporting member and the second supporting member in respective directions different from each other. The belt-type sheet conveying unit includes a belt, a first rotary belt holding member, a second rotary belt holding member, a first supporting member, and a second supporting member.

Abstract: A sheet conveying device, that can be included in an image forming apparatus, includes a first conveying unit to convey a sheet in a first sheet conveying direction, a second conveying unit including a sheet holding section to hold and transfer the sheet in a second sheet conveying direction, a sheet conveying path provided between the first conveying unit and the second conveying unit, a belt-type sheet conveying unit including a belt and first and second rotary belt holding members, a shaft holding member to hold the first and second rotary belt holding members to be spaced at a given constant interval, and a regulation member to regulate a movement of the belt in the sheet width direction.

Abstract: A functional unit positioning device for positioning a functional unit detachably attachable to an apparatus body, includes a biasing device that biases the functional unit in a unit-out direction; and a stopper mechanism having a first stopper and a second stopper, the stopper mechanism exerting and releasing control over release of the functional unit. The biasing device biases the functional unit by the biasing device so that the second stopper comes in contact with the first stopper to set the functional unit in a locked position in a unit in-out direction. The biasing device is also configured to change the magnitude of a bias force on the functional unit from low to high when the functional unit is inserted and advanced up to a predetermined position into the apparatus body.

Abstract: A sheet conveying device, that can be included in an image forming apparatus, includes first and second conveying units configured to hold and convey a sheet, a first sheet conveying path between the first and second conveying units, and a registration unit to change a positional condition of the sheet conveyed by the second conveying unit. In at least one embodiment, the second conveying unit includes a moving and guiding unit and a rotary conveyance unit facing each other and forming a sheet holding section therebetween to hold and convey the sheet, and the moving and guiding unit and the rotary conveyance unit are disposed in the vicinity of the first conveying unit so that a distance between the second conveying unit and the registration unit is relatively increased.

Abstract: A sheet elevating apparatus for use in a sheet tray cassette detachably installable to an image forming apparatus includes an elevation driving source, a first coupling, an elevation member, a second coupling, and an elevation controller. The elevation driving source is mounted to the image forming apparatus. The first coupling is connected to the elevation driving source and has a home position. The elevation member elevates a plurality of recording sheets placed on an elevating base plate of the sheet tray cassette. The second coupling is connected to the elevation member and is engaged with the first coupling set at the home position when the sheet tray cassette is installed in the image forming apparatus. The elevation controller drives the elevation driving source to set the first coupling to the home position when the sheet tray cassette is pulled out.

Abstract: An image forming apparatus includes image forming and sheet feeding mechanisms. The sheet feeding mechanism includes a bottom plate, a first roller, a separator including second and third rollers, and a sensor. The bottom plate loads sheets. The first roller feeds an uppermost sheet of the sheets loaded on the bottom plate. The separator separates the uppermost sheet from the other sheets when a plurality of sheets are fed by the first roller. The sensor is disposed between heads of the sheets loaded on the bottom plate and the separator and detects the uppermost sheet fed by the first roller. The image forming apparatus further includes a controller for driving the first roller to feed a next uppermost sheet loaded on the bottom plate when the sensor does not detect the next uppermost sheet when a tail portion of the previous sheet passes the separator.

Abstract: A paper feed apparatus which is capable of avoiding an erroneous transfer of recording sheets includes a plurality of selectable paper handling mechanisms and a controller. The paper handling mechanisms include a base plate storing recording sheets, an elevator moving the base plate, a first detector detecting whether an uppermost-positioned paper sheet of the recording sheets is positioned at a predetermined paper feed position, a feed roller rotating in a paper feed direction, a separation roller in contact with the feed roller with a reverse driving force, a pick-up roller transferring an uppermost-positioned sheet to a nip portion between the feed and separation rollers, a pushing member pushing the separation roller to contact the feed roller, and a release member releasing the separation roller from contact with the feed roller.

Abstract: An image forming apparatus including a sheet feeding device that is driven by a driving device through an interval device. The interval device can transfer the driving force only when a coil in the interval device is not electrified. Accordingly, when the feeding device is in active condition, the coil and the interval device do not become hotter and sheet feeding becomes more reliable.