Abstract: A belt unit includes a belt that is endless, a plurality of stretching rollers, a pair of side frames and one or more shafts. The side frames are each provided with bearing holes that rotatably support opposite end parts of the stretching rollers, and positioning holes into which opposite end parts of the shafts are inserted. The shafts each have formed therein a first engagement groove that engages with a first holding jig. The stretching rollers each have formed therein a second engagement groove that engages with a second holding jig. When the first engagement groove is in engagement with the first holding jig, the shafts are arranged opposite the positioning holes corresponding thereto, and have a phase thereof restricted in a circumferential direction thereof. When the second engagement groove is in engagement with the second holding jig, the stretching rollers are arranged opposite the bearing holes corresponding thereto.

Abstract: An image forming apparatus includes a photoconductor drum, a developing roller, a first shaft provided for one of the photoconductor drum and the developing roller, a second shaft provided for the other of the photoconductor drum and the developing roller, a first housing supporting the first shaft, and removable in an axial direction of the first shaft, a second housing supporting the second shaft, and removable in an axial direction of the second shaft, a first contact member provided on an axial end portion of the first housing, a second contact member provided on an axial end portion of the second housing, and located in contact with the first contact member, a first cover covering the first contact member, and a first cleaning device provided on the first cover, and configured to rub against the second contact member, when the second housing is inserted or removed.

Abstract: A belt unit includes a belt that is endless, a plurality of stretching rollers, a pair of side frames and one or more shafts. The side frames are each provided with bearing holes that rotatably support opposite end parts of the stretching rollers, and positioning holes into which opposite end parts of the shafts are inserted. The shafts each have formed therein a first engagement groove that engages with a first holding jig. The stretching rollers each have formed therein a second engagement groove that engages with a second holding jig. When the first engagement groove is in engagement with the first holding jig, the shafts are arranged opposite the positioning holes corresponding thereto, and have a phase thereof restricted in a circumferential direction thereof. When the second engagement groove is in engagement with the second holding jig, the stretching rollers are arranged opposite the bearing holes corresponding thereto.

Abstract: An intermediate transfer device includes an intermediate transfer belt, a plurality of primary transfer rollers, a plurality of pairs of support members, a biasing member, a pair of movable members, and a pair of frame members. The plurality of pairs of support members rotatably support both end parts of respective rotary shafts of the plurality of primary transfer rollers and are pivotable in directions in which the primary transfer rollers approach and separate from the intermediate transfer belt. The pair of movable members makes contact with the support members on both end sides of the rotary shafts of the plurality of primary transfer rollers so as to cause the support members to pivot. In a rotation axis direction of the primary transfer rollers, the movable members are disposed between the pair of frame members and within an extending range of the intermediate transfer belt.

Abstract: An image forming apparatus includes a plurality of image carrying members, an intermediate transfer belt, a plurality of rollers, and a correcting mechanism. The intermediate transfer belt is endless and, to it, toner images formed on the image carrying members respectively are transferred by being sequentially superposed on each other. The correction mechanism includes a slanted bearing, which rotatably supports a tension roller, and a main body guide roller, which makes contact with the slanted bearing when it moves as a result of the intermediate transfer belt meandering and which moves the slanted bearing along with one end of the tension roller in the axial direction in the direction perpendicular to the axial direction to correct meandering of the intermediate transfer belt with respect to the tension roller. The main body guide roller is a rotary member which rotates while in contact with the slanted bearing.

Abstract: An intermediate transfer device includes an intermediate transfer belt, a plurality of primary transfer rollers, a plurality of pairs of support members, a biasing member, a pair of movable members, and a pair of frame members. The plurality of pairs of support members rotatably support both end parts of respective rotary shafts of the plurality of primary transfer rollers and are pivotable in directions in which the primary transfer rollers approach and separate from the intermediate transfer belt. The pair of movable members makes contact with the support members on both end sides of the rotary shafts of the plurality of primary transfer rollers so as to cause the support members to pivot. In a rotation axis direction of the primary transfer rollers, the movable members are disposed between the pair of frame members and within an extending range of the intermediate transfer belt.

Abstract: An image forming apparatus includes a plurality of image carriers, an intermediate transfer belt, a plurality of rollers, a correction mechanism, and a belt cleaning unit. The intermediate transfer belt has an endless shape, and toner images respectively formed on the plurality of image carriers are sequentially overlaid and transferred thereto. The correction mechanism moves one end side in an axial direction of a tension roller along a direction perpendicular to the axial direction, so as to correct meandering of the intermediate transfer belt with respect to the tension roller. The belt cleaning unit includes a cleaning blade that is disposed in such a manner that its tip portion contacts with an outer circumferential surface of the intermediate transfer belt at a position facing the tension roller via the intermediate transfer belt, so as to remove extraneous matter from the outer circumferential surface of the intermediate transfer belt.

Abstract: An image forming apparatus includes a plurality of image carriers, an intermediate transfer belt, a plurality of rollers, a correction mechanism, and a belt cleaning unit. The intermediate transfer belt has an endless shape, and toner images respectively formed on the plurality of image carriers are sequentially overlaid and transferred thereto. The correction mechanism moves one end side in an axial direction of a tension roller along a direction perpendicular to the axial direction, so as to correct meandering of the intermediate transfer belt with respect to the tension roller. The belt cleaning unit includes a cleaning blade that is disposed in such a manner that its tip portion contacts with an outer circumferential surface of the intermediate transfer belt at a position facing the tension roller via the intermediate transfer belt, so as to remove extraneous matter from the outer circumferential surface of the intermediate transfer belt.

Abstract: An image forming apparatus includes a plurality of image carrying members, an intermediate transfer belt, a plurality of rollers, and a correcting mechanism. The intermediate transfer belt is endless and, to it, toner images formed on the image carrying members respectively are transferred by being sequentially superposed on each other. The correction mechanism includes a slanted bearing, which rotatably supports a tension roller, and a main body guide roller, which makes contact with the slanted bearing when it moves as a result of the intermediate transfer belt meandering and which moves the slanted bearing along with one end of the tension roller in the axial direction in the direction perpendicular to the axial direction to correct meandering of the intermediate transfer belt with respect to the tension roller. The main body guide roller is a rotary member which rotates while in contact with the slanted bearing.

Abstract: A fixing device includes a fixing member, a pressuring member and a temperature sensing part. The fixing member heated by a heat source contacts with a recording medium to heat a toner image on the recording medium. The pressuring member pressures the recording medium to the fixing member. The temperature sensing part in non-contact with the fixing member includes an infrared sensing element sensing infrared rays from the fixing member and a condensing member condensing the infrared rays to the infrared sensing element. Detection temperature of the fixing member is calculated with a sensing value by the infrared sensing element. The detection temperature or control temperature of the heat source is corrected with temperature deference between the infrared sensing element and the condensing member. Heating of the fixing member is controlled with the corrected detection temperature and the control temperature or the detection temperature and the corrected control temperature.

Abstract: A fixing device includes a fixing member, a pressuring member and a temperature sensing part. The fixing member heated by a heat source contacts with a recording medium to heat a toner image on the recording medium. The pressuring member pressures the recording medium to the fixing member. The temperature sensing part in non-contact with the fixing member includes an infrared sensing element sensing infrared rays from the fixing member and a condensing member condensing the infrared rays to the infrared sensing element. Detection temperature of the fixing member is calculated with a sensing value by the infrared sensing element. The detection temperature or control temperature of the heat source is corrected with temperature deference between the infrared sensing element and the condensing member. Heating of the fixing member is controlled with the corrected detection temperature and the control temperature or the detection temperature and the corrected control temperature.

Abstract: An operation panel used in an image forming apparatus has a panel face, a semi-transparent member of a black or similar color, and a light source. The panel face has an operation region. The semi-transparent member is arranged such that its top face is approximately flush with the panel face at least along a peripheral part of it. The light source is arranged under the semi-transparent member in the peripheral part of the panel face.

Abstract: A toner case includes a case main body, a shutter mount and a shutter. The case main body contains a toner to be replenished to a development device provided in an apparatus main body and is detachably attached to the apparatus main body. The case main body has an opened face on which a discharge port is arranged and the discharge port corresponds to a replenishment port of the development device in a state where the case main body is attached to the apparatus main body. The shutter mount is provided to form a gap between the opened face of the case main body and the shutter mount. The shutter is provided between the opened face of the case main body and the shutter mount to be slidable to open and close the discharge port. The shutter mount includes a film which comes into sliding contact with the shutter.

Abstract: An operation panel used in an image forming apparatus has a panel face, a semi-transparent member of a black or similar color, and a light source. The panel face has an operation region. The semi-transparent member is arranged such that its top face is approximately flush with the panel face at least along a peripheral part of it. The light source is arranged under the semi-transparent member in the peripheral part of the panel face.

Abstract: A toner case includes a case main body, a shutter mount and a shutter. The case main body contains a toner to be replenished to a development device provided in an apparatus main body and is detachably attached to the apparatus main body. The case main body has an opened face on which a discharge port is arranged and the discharge port corresponds to a replenishment port of the development device in a state where the case main body is attached to the apparatus main body. The shutter mount is provided to form a gap between the opened face of the case main body and the shutter mount. The shutter is provided between the opened face of the case main body and the shutter mount to be slidable to open and close the discharge port. The shutter mount includes a film which comes into sliding contact with the shutter.

Abstract: An image reading apparatus (6) includes a document placing table (6a) to an upper surface of which a contact glass (25) is fixed, and a document pressing device (24) supported at an end of the document placing table (6a) to be openable/closable via a hinge portion, and having, on its back surface side, a document presser (30) that presses a document placed on the contact glass (25). The document pressing device (24) includes a light transmission window (31) transmitting light in a front-surface-to-back-surface direction of the document pressing device (24). The light transmission window (31) is disposed at a position not overlapping with the contact glass (25) when the document pressing device (24) is at the closure position, and when the document pressing device (24) has moved in an opening direction from the closure position, light that has passed through the light transmission window (31) reaches the contact glass (25).

Abstract: An image reading apparatus (6) includes a document placing table (6a) to an upper surface of which a contact glass (25) is fixed, and a document pressing device (24) supported at an end of the document placing table (6a) to be openable/closable via a hinge portion, and having, on its back surface side, a document presser (30) that presses a document placed on the contact glass (25). The document pressing device (24) includes a light transmission window (31) transmitting light in a front-surface-to-back-surface direction of the document pressing device (24). The light transmission window (31) is disposed at a position not overlapping with the contact glass (25) when the document pressing device (24) is at the closure position, and when the document pressing device (24) has moved in an opening direction from the closure position, light that has passed through the light transmission window (31) reaches the contact glass (25).

Abstract: A driving device includes shaft, support member, restraining member, and connection portion. Shaft has a screw portion formed on an outer peripheral surface thereof. Support member rotatably supports shaft. Restraining member restrains shaft so as not to be movable in an axial direction thereof. Connection portion is formed in one end portion of shaft, and has output-side joint member detachably connected thereto. Input-side joint member is engaged by thread with screw portion of shaft so as to be rotatably supported. By being driven to rotate by drive source, input-side joint member is movable between connection position where input-side joint member is connected to output-side joint member and withdrawal position where connection is cut off. Driving device includes compression spring. When input-side joint member is moved from withdrawal position to connection position by drive source, compression spring compressively deform, while being sandwiched by input-side joint member and output-side joint member.

Abstract: An image forming apparatus includes a fixing unit, a first support portion, and a second support portion. First support portion fits with and positions first supported portion, which is end of fixing unit, in up-down direction and supports first supported portion movably in insertion direction of fixing unit toward attachment position. Second support portion fits with and positions second supported portion, which is another end of fixing unit, in up-down direction and supports second supported portion movably in insertion direction. Height adjustment portion adjusts height position of fixing unit by moving second support portion in up-down direction. The first support portion includes vertical surface facing first supported portion and extending in up-down direction, and vertical surface has projection at an end thereof on foreside of insertion direction, the projection projecting from the vertical surface in first direction of going away from the vertical surface.

Abstract: A sheet feeding device includes a feeding tray, a conveying device, an ejecting tray, a feeding guide and a conveying rib. On the feeding tray, a sheet is placed. The conveying device feeds the sheet on the feeding tray to an image reading device. The ejecting tray receives the sheet after image reading. The feeding guide is configured to be movable in a direction intersecting a feeding direction of the sheet and to regulate a position in a width direction of the sheet on the feeding tray. The conveying rib is configured to be movable in interlocking with movement of the feeding guide and to lead the sheet to be ejected onto the ejecting tray.