Abstract: An image forming apparatus includes a transfer unit, a fixing unit, a first conveyance unit which includes a first conveyance rotator, a first suction fan, and a first suction port, a second conveyance unit which includes a second conveyance rotator, a second suction fan, and a second suction port, and a control unit. The control unit is configured to execute a first mode of changing a rotational speed of the second suction fan from a first rotational speed to a second rotational speed lower than the first rotational speed after a leading edge of the sheet passes through the fixing unit in a case where a sheet having a length longer than a length from the fixing unit to a downstream end of the first suction port in the sheet conveyance direction is conveyed.

Abstract: An image forming apparatus includes a transfer unit, a fixing unit, a first conveyance unit which includes a first conveyance rotator, a first suction fan, and a first suction port, a second conveyance unit which includes a second conveyance rotator, a second suction fan, and a second suction port, and a control unit. The control unit is configured to execute a first mode of changing a rotational speed of the second suction fan from a first rotational speed to a second rotational speed lower than the first rotational speed after a leading edge of the sheet passes through the fixing unit in a case where a sheet having a length longer than a length from the fixing unit to a downstream end of the first suction port in the sheet conveyance direction is conveyed.

Abstract: A sheet conveyance apparatus includes first and second abutment surfaces in contact a leading edge of a conveyed sheet before the sheet is nipped by a conveyance portion, which nips the sheet while the first and second abutment members are moving from respective standby positions together with first and second rotary members by being pressed by the leading edge. The first and second rotary members are in contact with the sheet being conveyed by the second conveyance portion after the leading edge of the sheet passes through the first abutment surface, the first rotary member, and the second abutment surface, and the second rotary member, and the first and second abutment members move toward standby positions by urging members after a trailing edge of the sheet passing through the first and second rotary members.

Abstract: A drive transmission device includes a first gear, a cam configured to rotate in interrelation with rotation of the first gear and capable of changing a state of two members between a pressed state and a pressure-released state, a pressing member configured to press the cam, and a second gear configured to transmit drive to the first gear in engagement with the first gear. At least one of the first and second gears includes first teeth provided at positions corresponding to an engaging region in which the first gear is engaged with the second gear when the state of the two members is changed from the pressure-released state to the pressed state and includes second teeth provided at positions corresponding to a region other than the engaging region. Tooth thicknesses of the first teeth are thicker than tooth thicknesses of the second teeth.

Abstract: A sheet conveyance apparatus includes a first conveyance portion configured to convey a sheet, an abutment member including an abutment surface against which a leading edge of the sheet conveyed by the first conveyance portion abuts, the abutment member configured to move from a standby position by the abutment surface being pressed by the sheet, a second conveyance portion, an urging member configured to urge the abutment member toward the standby position, and a rotary member supported rotatably on the abutment member, wherein the rotary member is in contact with the sheet being conveyed by the second conveyance portion, and the abutment member is separated from the sheet in a state where the rotary member is in contact with the sheet being conveyed by the second conveyance portion after the leading edge of the sheet being conveyed passes the abutment surface.

Abstract: A drive transmission device includes a first gear, a cam configured to rotate in interrelation with rotation of the first gear and capable of changing a state of two members between a pressed state and a pressure-released state, a pressing member configured to press the cam, and a second gear configured to transmit drive to the first gear in engagement with the first gear. At least one of the first and second gears includes first teeth provided at positions corresponding to an engaging region in which the first gear is engaged with the second gear when the state of the two members is changed from the pressure-released state to the pressed state and includes second teeth provided at positions corresponding to a region other than the engaging region. Tooth thicknesses of the first teeth are thicker than tooth thicknesses of the second teeth.

Abstract: A drive transmission device includes a first gear, a cam configured to rotate in interrelation with rotation of the first gear and capable of changing a state of two members between a pressed state and a pressure-released state, a pressing member configured to press the cam, and a second gear configured to transmit drive to the first gear in engagement with the first gear. At least one of the first and second gears includes first teeth provided at positions corresponding to an engaging region in which the first gear is engaged with the second gear when the state of the two members is changed from the pressure-released state to the pressed state and includes second teeth provided at positions corresponding to a region other than the engaging region. Tooth thicknesses of the first teeth are thicker than tooth thicknesses of the second teeth.

Abstract: An image forming apparatus including an apparatus main body including an image forming device that forms an image on a recording material, a unit detachably mounted in the apparatus main body, a switching member pivotably provided in the apparatus main body, wherein while in a state in which the switching member has entered into the unit mounted in the apparatus main body, the switching member selectively switches a route through which the recoding material is guided, and a retracting member provided in the apparatus main body, wherein in a course of dismounting the unit from the apparatus main body, the retracting member retracts the switching member to an outside of a mount area of the unit.

Abstract: An image forming apparatus including an apparatus main body including an image forming device that forms an image on a recording material, a unit detachably mounted in the apparatus main body, a switching member pivotably provided in the apparatus main body, wherein while in a state in which the switching member has entered into the unit mounted in the apparatus main body, the switching member selectively switches a route through which the recoding material is guided, and a retracting member provided in the apparatus main body, wherein in a course of dismounting the unit from the apparatus main body, the retracting member retracts the switching member to an outside of a mount area of the unit.

Abstract: An image forming apparatus includes a main assembly and a unit detachably mountable to the main assembly. The main assembly includes a positioning portion. The unit includes a portion-to-be-positioned engaging with the positioning portion and a grip portion configured to be gripped by a user when the unit is demounted from the main assembly. The main assembly further includes an inclined surface provided immediately in front of the positioning portion with respect to a mounting direction of the unit to the main assembly and configured to guide the portion-to-be-positioned to the positioning portion. The grip portion includes a grip surface configured to receive a force exerted in a pulling-out direction of the unit by the user when the user pulls out the unit from the main assembly. The grip surface and the inclined surface form an angle of substantially not less than 90°.

Abstract: A drive transmission device includes a first gear, a cam configured to rotate in interrelation with rotation of the first gear and capable of changing a state of two members between a pressed state and a pressure-released state, a pressing member configured to press the cam, and a second gear configured to transmit drive to the first gear in engagement with the first gear. At least one of the first and second gears includes first teeth provided at positions corresponding to an engaging region in which the first gear is engaged with the second gear when the state of the two members is changed from the pressure-released state to the pressed state and includes second teeth provided at positions corresponding to a region other than the engaging region. Tooth thicknesses of the first teeth are thicker than tooth thicknesses of the second teeth.

Abstract: A frame for an image forming apparatus includes a first side plate and a second side plate, a post, and a stay. The post includes a first side portion which is a surface opposing the first side plate and which includes a first fastening portion to which the first side plate is fastened, and a second side portion which is formed by being bent from the first side portion in a direction substantially perpendicular to the first side portion and which includes a second fastening portion, to which the stay is fastened, positioned at a height different from a height of the first fastening portion with respect to the vertical direction. The second side portion is continuously formed at least from the first fastening portion to the second fastening portion with respect to the vertical direction.

Abstract: An image forming apparatus includes an image reading portion; an image forming portion; a first casing; a second casing including a space which continuously opens to two directions perpendicular to not only the vertical direction but also each other and including a mounting portion where the first casing is mountable at a position where the space does not continuously open to the two directions; one or more supporting portion; and one or more auxiliary supporting portion. A gap is formed between itself and the other one of the first casing and the mounting portion in a state in which no load is externally exerted on the first casing, and wherein the auxiliary supporting portion contacts the other one when a load not less than a predetermined load is externally exerted on an upper portion of the first casing downward at a position deviated from the mounting portion.

Abstract: a fastened structure comprising: a first member provided with a female screw; a second member provided with an opening; and a male screw fastening the first member and the second member with each other and including a male screw portion, and a head portion having a bearing surface, wherein the male screw portion is threaded in the female screw through the opening of the second member, wherein the second member is provided with a substantially circular folded portion including a curved surface defining the opening and including a free end having an edge pressed against the bearing surface of the male screw.

Abstract: A frame for an image forming apparatus includes a first side plate and a second side plate, a post, and a stay. The post includes a first side portion which is a surface opposing the first side plate and which includes a first fastening portion to which the first side plate is fastened, and a second side portion which is formed by being bent from the first side portion in a direction substantially perpendicular to the first side portion and which includes a second fastening portion, to which the stay is fastened, positioned at a height different from a height of the first fastening portion with respect to the vertical direction. The second side portion is continuously formed at least from the first fastening portion to the second fastening portion with respect to the vertical direction.

Abstract: An image forming apparatus includes an image reading portion; an image forming portion; a first casing; a second casing including a space which continuously opens to two directions perpendicular to not only the vertical direction but also each other and including a mounting portion where the first casing is mountable at a position where the space does not continuously open to the two directions; one or more supporting portion; and one or more auxiliary supporting portion. A gap is formed between itself and the other one of the first casing and the mounting portion in a state in which no load is externally exerted on the first casing, and wherein the auxiliary supporting portion contacts the other one when a load not less than a predetermined load is externally exerted on an upper portion of the first casing downward at a position deviated from the mounting portion.

Abstract: a fastened structure comprising: a first member provided with a female screw; a second member provided with an opening; and a male screw fastening the first member and the second member with each other and including a male screw portion, and a head portion having a bearing surface, wherein the male screw portion is threaded in the female screw through the opening of the second member, wherein the second member is provided with a substantially circular folded portion including a curved surface defining the opening and including a free end having an edge pressed against the bearing surface of the male screw.

Abstract: A cleaning brush is not made slidably contact suctioning endless belts which pass inlets, and the cleaning brush is made slidably contact non-suctioning endless belts which do not pass the inlets. Consequently, it is possible to bring out paper dust and transfer remaining toner which adhere to the suctioning endless belts in attracting areas in which the inlet holes are formed, to the exterior of the apparatus by means of sheets to be conveyed. By contrast with this, from non-suctioning endless belts, the cleaning brush can clean and remove paper dust and transfer remaining toner which adhere to the non-suctioning endless belts.

Abstract: A cleaning brush is not made slidably contact suctioning endless belts which pass inlets, and the cleaning brush is made slidably contact non-suctioning endless belts which do not pass the inlets. Consequently, it is possible to bring out paper dust and transfer remaining toner which adhere to the suctioning endless belts in attracting areas in which the inlet holes are formed, to the exterior of the apparatus by means of sheets to be conveyed. By contrast with this, from non-suctioning endless belts, the cleaning brush can clean and remove paper dust and transfer remaining toner which adhere to the non-suctioning endless belts.

Abstract: A curl correcting device for correcting a curl of a sheet at a curved belt-nip portion includes an endless belt extending between a driving roller and a driven roller, and a pressing roller configured to press a belt surface of the endless belt. A stepping motor is controlled in accordance with a pressing amount of the pressing roller to the belt surface of the endless belt to adjust a speed of the endless belt, thereby preventing the speed from being decreased.