Abstract: An image forming apparatus includes an image forming unit, a body housing and a temporarily placement part. The image forming forms an image. The image forming unit is attached to and detached from the body housing. The temporarily placement part is deployed outside the body housing, and the image forming unit can be temporarily placed on the temporarily placement part. The temporarily placement part includes an upper cover which coves an upper portion of the image forming unit placed on the temporarily placement part.

Abstract: An image forming apparatus includes an apparatus main body, a drum unit, and a developing unit. The developing unit includes a developing unit projection projecting out from opposite sides of the developing unit along an extension line of a rotation shaft of a developing roller. The apparatus main body includes a first developing projection guide portion configured to guide the developing unit projection from a first start position to a relay position in the apparatus main body, the relay position located closer to the photoconductor drum than the first start position. The drum unit includes a second developing projection guide portion configured to, succeeding from the first developing projection guide portion, guide the developing unit projection from the relay position to a first end position, the first end position located closer to the photoconductor drum than the relay position.

Abstract: An image forming apparatus includes an apparatus main body, a drum unit, and a developing unit. The developing unit includes a developing unit projection projecting out from opposite sides of the developing unit along an extension line of a rotation shaft of a developing roller. The apparatus main body includes a first developing projection guide portion configured to guide the developing unit projection from a first start position to a relay position in the apparatus main body, the relay position located closer to the photoconductor drum than the first start position. The drum unit includes a second developing projection guide portion configured to, succeeding from the first developing projection guide portion, guide the developing unit projection from the relay position to a first end position, the first end position located closer to the photoconductor drum than the relay position.

Abstract: An image forming apparatus includes an image forming apparatus body, a photosensitive drum, a developing part developing an electrostatic latent image formed on a peripheral surface of the photosensitive drum into a toner image by supplying a toner, a transfer part transferring the toner image from the peripheral surface of the photosensitive drum onto a sheet, and a fixing part fixing the toner image transferred on the sheet. The photosensitive drum, the developing part, the transfer part, and the fixing part are unitized as an image-formation-related unit and the image-formation-related unit is detachably housed in the image forming apparatus body.

Abstract: An image forming apparatus 100 includes a cassette fitting portion 1 which is provided in the main body of the image forming apparatus 100 and a paper feed cassette 30 which includes a sheet storage portion S. In the cassette fitting portion 1, a lift plate 50 is provided which raises and lowers a sheet 18. In the cassette base 31 of the sheet storage portion S, an opening portion 31a is formed in a position opposite the lift plate 50. The lift plate 50 is arranged selectively either in a lowered position in which the lift plate 50 is arranged below the cassette base 31 or in a raised position in which the lift plate 50 is protruded above the cassette base 31 through the opening portion 31a so as to allow the sheet 18 to be fed.

Abstract: An image forming apparatus 100 includes a cassette fitting portion 1 which is provided in the main body of the image forming apparatus 100 and a paper feed cassette 30 which includes a sheet storage portion S. In the cassette fitting portion 1, a lift plate 50 is provided which raises and lowers a sheet 18. In the cassette base 31 of the sheet storage portion S, an opening portion 31a is formed in a position opposite the lift plate 50. The lift plate 50 is arranged selectively either in a lowered position in which the lift plate 50 is arranged below the cassette base 31 or in a raised position in which the lift plate 50 is protruded above the cassette base 31 through the opening portion 31a so as to allow the sheet 18 to be fed.

Abstract: An image forming apparatus includes a conveying unit, a boss, a hook member and an auxiliary pressing member. The conveying unit is provided at an apparatus main body in a turnable manner and configured to form or open a nip area. The boss is provided at the apparatus main body. The hook member is provided at the conveying unit in a turnable manner and configured to be engaged with the boss when the conveying unit is turned to a position where the nip area is formed. The auxiliary pressing member is configured to press the hook member in a direction in which the hook member is engaged with the boss after the hook member is engaged with the boss. A direction in which the auxiliary pressing member presses the hook member is different from a turning direction of the conveying unit.

Abstract: An image forming apparatus includes a conveying unit, a boss, a hook member and an auxiliary pressing member. The conveying unit is provided at an apparatus main body in a turnable manner and configured to form or open a nip area. The boss is provided at the apparatus main body. The hook member is provided at the conveying unit in a turnable manner and configured to be engaged with the boss when the conveying unit is turned to a position where the nip area is formed. The auxiliary pressing member is configured to press the hook member in a direction in which the hook member is engaged with the boss after the hook member is engaged with the boss. A direction in which the auxiliary pressing member presses the hook member is different from a turning direction of the conveying unit.

Abstract: A transfer unit includes a transfer roller, a guide, a holder and a lever. The transfer roller is configured to be pressed against an image carrier to form a transferring nip and to transfer a toner image from the image carrier to a sheet at the transferring nip. The guide is configured to guide the sheet to the transferring nip. The holder is configured to support a rotating shaft of the transfer roller in a rotatable manner and to support the guide. The lever is configured to support the holder in a turnable manner around the rotating shaft so as to press the transfer roller against the image carrier. The guide has an engaged part. The lever has an engagement part which is engaged with the engaged part. An engagement of the engagement part with the engaged part prevents a turning of the guide with respect to the lever.

Abstract: An image forming apparatus includes a cover unit, a boss, a hook member, a biasing member and a pressing member. The cover unit is turnably provided on an apparatus main body to form and open a conveying path. The boss is provided on the apparatus main body. The hook member is turnably provided on the cover unit and engaged with the boss when the cover unit is turned to a position where the conveying path is formed. The biasing member is provided on the cover unit and biases the hook member in a direction in which the hook member is engaged with the boss. The pressing member is provided on the cover unit in an elastically deformable manner and abuts on the hook member from an upstream side of a turning direction of the hook member to a position where the hook member is engaged with the boss.

Abstract: A sheet feeding device includes a pickup roller, a feed roller, a feed holder and a mounting part. The pickup roller rotates around a first rotating shaft and then to feed a sheet. The feed holder supports the first rotating shaft. To the mounting part, the feed holder is mounted and dismounted. The mounting part has a pair of guide grooves. The feed holder has a pair of guide shafts protruding in a direction parallel to the first rotating shaft. The pair of guide shafts are guided along the pair of guide grooves. The pair of guide shafts are formed on an axis line different from an axis line of the first rotating shaft.

Abstract: A roller drive transmission device includes a drive input gear, a drive transmission gear, a roller unit and a ratchet mechanism. When a rotational drive force is input to the drive input gear and the drive transmission gear is slid to a first position, the drive input gear, the drive transmission gear and the roller unit are integrally rotated in a first rotational direction. When the input of the rotational drive force to the drive input gear is cut off and the roller unit is rotated, following a sheet, the drive transmission gear is slid to a second position and the roller unit and the drive transmission gear are decoupled. The ratchet mechanism includes a load adjustment mechanism configured to make a rotational load in the first rotational direction of the drive transmission gear arranged at the second position larger than a movement load in an axial direction.

Abstract: An image forming apparatus includes a cover unit, a boss, a hook member, a biasing member and a pressing member. The cover unit is turnably provided on an apparatus main body to form and open a conveying path. The boss is provided on the apparatus main body. The hook member is turnably provided on the cover unit and engaged with the boss when the cover unit is turned to a position where the conveying path is formed. The biasing member is provided on the cover unit and biases the hook member in a direction in which the hook member is engaged with the boss. The pressing member is provided on the cover unit in an elastically deformable manner and abuts on the hook member from an upstream side of a turning direction of the hook member to a position where the hook member is engaged with the boss.

Abstract: A transfer unit includes a transfer roller, a guide, a holder and a lever. The transfer roller is configured to be pressed against an image carrier to form a transferring nip and to transfer a toner image from the image carrier to a sheet at the transferring nip. The guide is configured to guide the sheet to the transferring nip. The holder is configured to support a rotating shaft of the transfer roller in a rotatable manner and to support the guide. The lever is configured to support the holder in a turnable manner around the rotating shaft so as to press the transfer roller against the image carrier. The guide has an engaged part. The lever has an engagement part which is engaged with the engaged part. An engagement of the engagement part with the engaged part prevents a turning of the guide with respect to the lever.

Abstract: An image forming apparatus includes a cover member, an opening/closing detecting device and an elastic member. The cover member is supported so as to open and close an opening formed in an apparatus main body. The opening/closing detecting device is configured to be switched into OFF state to detect that the cover member is in opening state where the opening is opened and into ON state to detect that the cover member is in closing state where the opening is closed. The elastic member is interposed between the opening/closing detecting device and the cover member. The elastic member is configured to be deformed when the cover member closes the opening and then to switch the opening/closing detecting device from the OFF state into the ON state.

Abstract: An image forming apparatus includes an apparatus body, an outer cover, a conveyance unit, a movable roller, and an interlock mechanism. The outer cover is provided turnably between an outer closing position forming one surface of the apparatus body and an outer opening position in which the one surface of the apparatus body is set openable. The conveyance unit is provided turnably between an inner closing position in which an inside of the apparatus body is set closable and an inner opening position in which the inside of the apparatus body is set openable. The movable roller is pressed by a fixed roller pivotally supported inside of the apparatus body when the conveyance unit is displaced to the inner closing position. The interlock mechanism interlocks an operation of opening the outer cover with an operation of opening the conveyance unit.

Abstract: A sheet feeding device includes a feed roller, a feed holder, a supporting frame and a driving shaft. The feed roller is configured to rotate around a rotating shaft. The feed holder is configured to support the feed roller. The supporting frame has a storage recessed part in which the feed holder is attachable and detachable along a direction crossing an axial direction of the rotating shaft. The driving shaft is supported to the supporting frame on one side of the storage recessed part in the axial direction. The storage recessed part has a guide part and a positioning part. The guide part is configured to guide the feed holder. The rotating shaft is coupled to the driving shaft by sliding the feed holder positioned at the aligning position by the positioning part in the axial direction.

Abstract: A roller drive transmission device includes a drive input gear, a drive transmission gear, a roller unit and a ratchet mechanism. When a rotational drive force is input to the drive input gear and the drive transmission gear is slid to a first position, the drive input gear, the drive transmission gear and the roller unit are integrally rotated in a first rotational direction. When the input of the rotational drive force to the drive input gear is cut off and the roller unit is rotated, following a sheet, the drive transmission gear is slid to a second position and the roller unit and the drive transmission gear are decoupled. The ratchet mechanism includes a load adjustment mechanism configured to make a rotational load in the first rotational direction of the drive transmission gear arranged at the second position larger than a movement load in an axial direction.

Abstract: A sheet feeding device includes a pickup roller, a feed roller, a feed holder and a mounting part. The pickup roller rotates around a first rotating shaft and then to feed a sheet. The feed holder supports the first rotating shaft. To the mounting part, the feed holder is mounted and dismounted. The mounting part has a pair of guide grooves. The feed holder has a pair of guide shafts protruding in a direction parallel to the first rotating shaft. The pair of guide shafts are guided along the pair of guide grooves. The pair of guide shafts are formed on an axis line different from an axis line of the first rotating shaft.

Abstract: An image forming apparatus includes a cover member, an opening/closing detecting device and an elastic member. The cover member is supported so as to open and close an opening formed in an apparatus main body. The opening/closing detecting device is configured to be switched into OFF state to detect that the cover member is in opening state where the opening is opened and into ON state to detect that the cover member is in closing state where the opening is closed. The elastic member is interposed between the opening/closing detecting device and the cover member. The elastic member is configured to be deformed when the cover member closes the opening and then to switch the opening/closing detecting device from the OFF state into the ON state.