JP4948655B2 - Image forming apparatus - Google Patents

Description

The present invention relates to an image forming apparatus copiers replacement roller member is detachable from the main body, a printer, a facsimile, an image forming apparatus such as MFP, printer.

  Conventionally, as this type of replacement roller member, there is known a transfer roller that can be attached to and detached from the main body of the image forming apparatus described in Patent Document 1. The transfer roller is disposed at a position facing the latent image carrier when mounted on the main body of the image forming apparatus, and on the back surface of the recording paper when the recording paper passes between the latent image carrier and the transfer roller. The recording paper is used to convey the recording paper along the moving direction of the surface of the latent image carrier while abutting the surface of the recording paper against the latent image carrier. This transfer roller is composed only of a cored bar serving as a shaft and a conductive elastic body serving as a roller formed around the shaft, and the transfer roller alone can be replaced.

  Conventionally, the replacement work of the replacement roller member is generally performed by a professional service person who is accustomed to the replacement work, and is rarely performed by a general user who is unfamiliar with the replacement work. For this reason, the handling of the replacement roller member at the time of replacement work has not been much emphasized. However, in recent image forming apparatuses, an opportunity for a general user to replace the replacement roller member of the image forming apparatus by himself / herself is increasing in order to reduce the cost burden. Therefore, it is desired to improve the handleability of the replacement roller member so that even a general user can replace the replacement roller member appropriately and easily.

The replacement transfer roller described in Patent Document 1 has the same configuration as that of a non-removable transfer roller that is not supposed to be replaced, and does not consider handling at the time of replacement work. Therefore, the following problems arise. That is, when a general user performs the replacement work of the replacement transfer roller, the transfer roller has a surface of the roller portion by hand, or has a shaft portion that protrudes outward in the rotation axis direction from both ends of the roller portion of the transfer roller. It is assumed that However, in the former case, hand oil adheres to the surface of the roller portion of the transfer roller, which may cause problems such as recording material conveyance failure in the image forming operation after the transfer roller is mounted. In the latter case, since the shaft portion of the transfer roller is a portion that fits into the bearing of the image forming apparatus main body, there is a problem that workability when the shaft portion held by hand is fitted into the bearing is poor.
Such a problem may occur not only in the transfer roller but also in other roller members provided in the image forming apparatus.

The present invention has been made in view of the above background, and the object of the present invention is to improve the handleability of the replacement roller member during the replacement work, and to make the replacement work appropriate and easy for the operator. be done is to provide the images forming apparatus capable.

In order to achieve the above object, an invention according to claim 1 is provided with a roller member replaceable with respect to the main body of the image forming apparatus, and in the image forming apparatus for forming an image on a sheet, the roller member rotates about the center. A shaft portion having two shaft end portions and a shaft portion having two shaft ends, and two roller end portions. The two shaft end portions protrude from the roller end portions outward in the rotation shaft direction. A roller portion that covers the shaft portion along the two shafts, two roller mounting portions provided at the two shaft end portions, a sheet that is being conveyed, and that can rotate relative to the shaft end portion . A sliding guide member; a cylindrical portion into which the shaft end portion is inserted; and at least one sliding bearing member attached to at least one of the two shaft end portions; and the sliding bearing member It protrudes from the outer surface of the tubular portion radially outwardly An engaging portion provided, along the rotation axis provided on at least one of the roller mounting portion of said two rollers mounting portion, and, on the shaft end the sliding bearing member along said rotation axis inserted possess the engaged portion to be engaged with the engaging portion when said engaged portion is a pair of engaged portions provided at intervals from one another as viewed from the rotation axis direction And at least one sliding bearing member is inserted between the pair of engaged portions by inserting the shaft end portion into the cylindrical portion from the outer side in the roller axial direction. The rotation with respect to the roller mounting portion is restricted .
Also, the second aspect of the present invention, in the image forming apparatus 請 Motomeko 1, upper Symbol engaged portion, said the the roller radially a clamping portion for clamping the peripheral surface of the engagement portion To do.
According to a third aspect of the present invention, in the image forming apparatus according to the second aspect , when the sliding bearing member is inserted into the shaft end along the rotating shaft, the holding portion holds the engaging portion . Thus, the sliding bearing member is fixed to the at least one roller mounting portion in a snap-fit manner.
According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the roller mounting portion and the conveyance guide member are integrally formed. is there.
According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the roller mounting portion and the conveyance guide member are configured as separate members. Is.
According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, the sliding bearing member is made of a resin having low friction with respect to the outer peripheral surface of the shaft end portion. It is characterized by being formed.
According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, the operator grips the roller member on the outer side in the rotation axis direction than the conveyance guide member. It has the grip member for doing.
According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, the two slide bearing members are provided, and each slide bearing member is a rotation shaft of the roller mounting portion. It is attached to each of the two shaft end portions at a position on the outer side in the direction, and there are two engaging portions and two engaged portions, respectively, and each engaged portion is connected to the roller attaching portion along the rotating shaft. It is characterized by being provided for each.
According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, the roller attachment portion is attached to the shaft end portion via a ball bearing. Is.
According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the first to ninth aspects, the image forming apparatus includes a rotation unit that is rotatable with respect to the main body of the image forming apparatus, and the roller member rotates the rotation member. The moving unit is detachable from the moving unit.
The invention according to claim 11 is the image forming apparatus according to claim 10 , wherein a clamping member is provided in the main body of the image forming apparatus, and the roller member is attached to the rotating unit in order to attach the roller member to the main body of the image forming apparatus. The sliding bearing member of the roller member is clamped by the clamping member when the rotating unit is mounted and rotated.

In the present invention, a replaceable roller member, are equipped with rotatable conveying guide member for the two axial end portions respectively extending from the roller unit opposite ends to the roller rotation axis outward. Thereby, the operator who replaces this roller member can handle it by holding the conveyance guide member in his / her hand. As a result, the roller member can be handled without having to hold the roller part surface or the shaft part of the roller member, so that problems caused by the hand oil adhering to the roller part surface and the shaft part can be eliminated. There is no problem such as poor workability when fitted into the bearing of the main body.

  According to the present invention, it is possible to improve the handleability of the replacement roller member at the time of replacement work, and to achieve an excellent effect that the replacement work can be performed appropriately and easily for the operator.

1 is an external perspective view showing a secondary transfer roller that can be attached to and detached from a full-color printer according to an embodiment. FIG. 2 is a schematic configuration diagram of the full-color printer. Explanatory drawing of the conveyance path of the full-color printer. Explanatory drawing of the opening / closing operation | movement of the duplex unit with which the full color printer is provided. The enlarged view which shows the edge part of the secondary transfer roller. (A) is a perspective view of the sub-rotation unit with which the duplex unit is provided. (B) is a perspective view from the other direction of the sub-rotation unit. Explanatory drawing which shows a motion when mounting | wearing the same secondary transfer roller to the same subrotation unit. FIG. 4A is an enlarged perspective view of an engagement portion between the secondary transfer roller and the sub-rotation unit. (B) is explanatory drawing which shows the cross section orthogonal to the roller axial direction of the same engagement location. Explanatory drawing which showed the cross section orthogonal to the rotating shaft direction in the state in which the secondary transfer roller was attached to the subrotation unit. Explanatory drawing which shows the modification of the guide piece provided in the secondary transfer roller. Explanatory drawing which shows the other modification of the guide piece provided in the secondary transfer roller. Explanatory drawing which showed the packing member when the replacement part in the state which packed the secondary transfer roller was seen from the roller axial direction in the cross section. The roller axial direction sectional view which shows the example of the other fixing member which fixes a cap with respect to the roller attaching part of the secondary transfer roller. FIG. 6 is an explanatory diagram showing another example of a mark portion provided on the cap of the secondary transfer roller. Explanatory drawing which shows the example which employ | adopted the bearing member which consists of a ball bearing instead of the cap. Explanatory drawing which shows the modification of the example which employ | adopted the same bearing member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 is a cross-sectional configuration diagram showing an outline of a full-color printer as an example of the image forming apparatus according to the present invention.
This full-color printer is provided with an intermediate transfer belt 11 stretched over a plurality of rollers at substantially the center of the apparatus main body 50, and there are four along the belt surface of the intermediate transfer belt 11 facing downward in the vertical direction. Image forming units 10M, 10C, 10Y, and 10Bk.

  Each of the image forming units 10M, 10C, 10Y, and 10Bk includes a photosensitive drum 1 as a latent image carrier. Around these photosensitive drums 1, a charging device, a developing device, a cleaning device, and the like are arranged, respectively. A primary transfer roller 12 serving as a primary transfer unit is provided inside the intermediate transfer belt 11 at a position facing each photoconductor drum 1. In the case of the present embodiment, the four image forming units 10M, 10C, 10Y, and 10Bk are configured in the same structure, but the developer colors handled by the developing device of each image forming unit are magenta, cyan, yellow, and black. The four colors are different. In the present embodiment, the four image forming units 10M, 10C, 10Y, and 10Bk are arranged in the order of magenta, cyan, yellow, and black from the left in the drawing. The image forming units 10M, 10C, 10Y, and 10Bk are detachably attached to the apparatus main body 50 as process cartridges.

  An optical writing device 14 is provided below each of the image forming units 10M, 10C, 10Y, and 10Bk. Although not shown, the optical writing device 14 has a polygon mirror, a mirror group, and the like, and irradiates the surface of the photosensitive drum 1 of each color image forming unit with light-modulated laser light. The optical writing device 14 may be provided for each of the image forming units 10M, 10C, 10Y, and 10Bk. However, using a common optical writing device is advantageous in terms of cost. In the present embodiment, the intermediate transfer belt 11 and the optical writing device 14 are also unitized and configured to be detachable from the apparatus main body 50.

  Further, two stages of paper feed cassettes 15a and 15b are set at the lower part of the apparatus main body 50, and paper feed means 16a and 16b corresponding to the respective paper feed cassettes are provided. Each of the paper feeding units 16a and 16b includes a calling roller, a supply roller, and a separation roller. A conveying roller pair 17 is provided for conveying a recording material such as transfer paper (hereinafter referred to as “paper”) fed by the paper feeding means 16a and 16b. A registration roller pair 18 is provided above the upper conveyance roller pair 17 (on the downstream side in the paper conveyance direction). Above the registration roller pair 18, a secondary transfer roller 100, which is a roller member that functions as a secondary transfer unit, faces a transfer counter roller 13 that is one of the rollers around which the intermediate transfer belt 11 is stretched. Is provided.

In addition, a transfer outlet guide 101 that is a conveyance guide member serving as a conveyance regulating member that regulates the conveyance direction of the sheet by contacting the sheet being conveyed is provided at a position adjacent to the upper side of the secondary transfer unit. A fixing device 20 is provided further downstream than the transfer outlet guide 101. Above the fixing device 20, first to third switching claws 21, 22, and 23 for switching the sheet conveyance direction are arranged. Each switching claw 21, 22, 23 is switched to a position indicated by a solid line and a virtual line in FIG. 3 by an actuator such as a solenoid (not shown). Reference numerals 24 to 27 denote transport roller pairs appropriately disposed in the paper transport path. Reference numerals 35 to 41 are paper sensors appropriately disposed in the paper conveyance path. Note that the paper conveyance path is appropriately guided by a member (not labeled) such as a guide plate.

  The upper surface of the apparatus main body 50 is configured as a paper discharge tray 30, and a paper discharge roller pair 29 for discharging paper to the paper discharge tray 30 is provided at the upper left of the fixing device 20. Yes.

In the present embodiment , a double-sided unit 60 that is a rotating unit is provided on the side of the apparatus. A switchback transport path 61 and a refeed path 62 are formed in the duplex unit 60. A first reverse roller pair 31 is provided at the inlet (upper side of the apparatus) of the switchback conveyance path 61, and a second reverse roller pair 32 is provided in the middle of the switchback conveyance path 61. The first and second reversing roller pairs 31 and 32 are configured to be rotatable forward and backward. A pair of conveying rollers 26 and 27 is arranged at a position where the refeeding path 62 is substantially divided into three equal parts. The above-described third switching claw 23 is disposed immediately next to the first reversing roller pair 31 and positioned at an entry portion from the switchback conveyance path 61 to the refeeding path 62.

  A manual feed tray 33 is provided on the side surface of the duplex unit 60 so that it can be pulled out and stored. FIG. 2 shows a state where the manual feed tray 33 is pulled out. In order to feed paper from the manual feed tray 33, a paper feed means 34 including a calling roller, a supply roller, and a separation roller is provided. A re-feed roller 28 is disposed on the side of the paper feed means 34 and inside the apparatus. The driven rollers are pressed against the upper and lower sides of the refeed roller 28, respectively. The re-feed roller 28 is configured to be able to rotate forward and backward. When the paper is re-feeded from the re-feed path 62, the re-feed roller 28 is rotated counterclockwise in the drawing to feed the paper from the manual feed tray 33. In this case, it is rotated clockwise in the figure.

Next, an image forming operation in the full color printer configured as described above will be briefly described.
The photosensitive drums 1 of the image forming units 10M, 10C, 10Y, and 10Bk are rotated in the clockwise direction in the figure by driving means (not shown), and the surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity by a charging device. Is done. The charged photosensitive drum surface is irradiated with laser light from the optical writing device 14, thereby forming an electrostatic latent image on the photosensitive drum surface. At this time, the image information exposed to each photosensitive drum 1 is single-color image information obtained by separating a desired full-color image into magenta, cyan, yellow, and black color information. Each color toner is applied from the developing device to the electrostatic latent image formed in this way, and visualized as a toner image.

  Further, the intermediate transfer belt 11 is driven counterclockwise in the drawing as indicated by an arrow in FIG. 2, and from each photosensitive drum 1 by the action of each primary transfer roller 12 in each of the image forming units 10M, 10C, 10Y, and 10Bk. The respective color toner images are sequentially superimposed and transferred onto the intermediate transfer belt 11. In this way, the intermediate transfer belt 11 carries a full-color toner image on the surface thereof.

  Note that a single color image can be formed by using any one of the image forming units 10M, 10C, 10Y, and 10Bk, and a two-color or three-color image can be formed. In the case of monochrome printing, image formation is performed using the rightmost Bk unit in the figure among the four image forming units.

  Residual toner adhering to the surface of the photosensitive drum after transferring the toner image is removed from the surface of the photosensitive drum by the cleaning device, and then the surface is subjected to the action of the static eliminator to initialize the surface potential and the next image. Prepare for formation.

  On the other hand, the paper is selectively fed from the paper feed cassettes 15a and 15b or the manual feed tray 33, and the toner image carried on the intermediate transfer belt 11 is timed by the registration roller pair 18 to the secondary transfer unit. Sent out. In the present embodiment, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the surface of the intermediate transfer belt is applied to the secondary transfer roller 100, whereby the toner image on the surface of the intermediate transfer belt is collectively transferred onto the sheet. The When the sheet on which the toner image is transferred passes through the fixing device 20, the toner image is melted and fixed on the sheet by heat and pressure. The fixed transfer material is discharged to a discharge tray 30 formed on the upper surface of the apparatus main body 50 by a pair of discharge rollers 29. A sheet conveyance path (when the sheet is fed from the sheet feeding cassettes 15a and 15b) during single-sided printing is indicated by a solid line [1] in FIG.

  An optional paper discharge tray (for example, a 4-bin tray having a sorting function) can be mounted on the upper surface of the apparatus above the second switching claw 22, and the fixed sheet can be discharged to the optional tray (not shown). It is. A paper transport path (after passing through the fixing device) when paper is discharged to the option tray is indicated by a broken line [2] in FIG.

  When printing on both sides of the sheet, the sheet having the toner image fixed on one side of the sheet is caused to enter the switchback conveyance path 61 by appropriately switching the first to third switching claws 21 to 23. In this case, the first and second switching claws 21 and 22 are switched to the positions of the virtual lines in FIG. Moreover, the 3rd switching nail | claw 23 is switched to the position of the continuous line of FIG. The first and second reversing roller pairs 31 and 32 are rotated in the forward direction (clockwise in FIG. 2). A conveyance path (however, after the conveyance roller pair 25) when the sheet enters the switchback conveyance path 61 is indicated by a two-dot chain line [3] in FIG.

  When the sensor 40 detects the trailing edge of the paper that has entered the switchback conveyance path 61, the first and second reversing roller pairs 31, 32 are rotated in the reverse direction (counterclockwise in FIG. 2) to reverse the paper. At this time, by switching the third switching claw 23 to the position of the imaginary line in FIG. 3, the reversed paper is sent to the refeed path 62.

  The sheet refeed path 62 is joined at the lower end portion with the sheet conveyance path from the manual feed tray 33, and further merged with the sheet conveyance path from the sheet feed cassettes 15 a and 15 b on the back side of the sheet refeed roller 28. The paper is transported in the refeed path 62 by the transport roller pairs 26 and 27, and further sent to the registration roller pair 18 by the refeed roller 28. A sheet conveyance path (however, from the third switching claw 23 to a portion joining the solid line [1]) passing through the refeed path 62 is indicated by a one-dot chain line [4] in FIG. In addition, a sheet conveyance path when the sheet is fed from the manual feed tray 33 (up to the position after the refeed roller 28) is shown by a dotted line [5] in FIG.

  By passing the paper reversed by the switchback transport path 61 through the refeed path 62, the front and back of the paper are reversed, and the toner image is transferred from the intermediate transfer belt 11 to the back of the paper, and the back image is fixed to the fixing device. By fixing at 20, the paper carrying the images on both the front and back sides is discharged to the paper discharge tray 30 or an optional tray (not shown), thereby completing double-sided printing.

  In the present embodiment, the double-sided unit 60 is provided so as to be swingable about a rotation shaft 63 provided at the lower part thereof, and the double-sided unit 60 can be opened and closed with respect to the apparatus main body 50. FIG. 4 shows a state where the duplex unit 60 is opened. The duplex unit 60 is supported by the apparatus main body 50 by a link mechanism (not shown), and stops at a predetermined position when opened. The opening angle at this time is preferably 45 ° or more and 90 ° or less with respect to the vertical direction from the viewpoint of facilitating replacement work of the secondary transfer roller described later. Further, in order to reduce the opening / closing force of the double-sided unit 60, it is preferable to provide a damper means in the link mechanism that supports the double-sided unit 60. As the damper means, one using a spring, an oil damper or the like can be used.

  Included in the duplex unit 60 and opened and closed with respect to the apparatus main body 50 are a guide plate (not shown) that forms a switchback conveyance path 61, a part of guide members 66 that form a refeed path 62, In addition to the sub-rotation unit 64, there are a third switching claw 23, first and second reversing roller pairs 31, 32, a manual feed tray 33, its paper feeding means 34, a refeed roller 28, and the like. The driven rollers 17 b of the two transport roller pairs 17 are also members included in the duplex unit 60.

  The sub-rotation unit 64 supports the secondary transfer roller 100, the driven roller 27b of the conveyance roller pair 27, the driven roller 28b of the refeed roller 28, and the paper sensor 41, and rotates around the rotation shaft 65 as a fulcrum. It is configured to move freely. Therefore, the refeed path 62 can be opened by rotating the auxiliary rotation unit 64 counterclockwise in the drawing. However, a stopper member (not shown) is provided, and the sub-rotation unit 64 cannot be rotated counterclockwise beyond the angle shown in FIG.

  One side (outside of the apparatus) of the refeed path 62 is defined by a guide member 66, and the opposite side (inside of the apparatus) is sequentially arranged from the top to one surface of the guide member 42, one surface of the fixing device 20, and the sub-rotation unit 64. When the duplex unit 60 is closed, a refeed path 62 is formed by the above-described members.

  When the duplex unit 60 is closed as shown in FIG. 2, the sub-rotation unit 64 is sandwiched between the apparatus main body 50 and the duplex unit 60 and is positioned at a predetermined position. At this time, the secondary transfer roller 100 is Opposed to the transfer facing roller 13 and pressed against the intermediate transfer belt 11, the driven rollers 17 b of the two transport roller pairs 17 are pressed against the respective drive rollers 17 a, and the transport roller pair 27 in the refeed path 62 is pressed. The driven roller 27b is brought into pressure contact with the driving roller 27a to be operable.

  When the duplex unit 60 is opened as shown in FIG. 4, the secondary transfer roller 100 is separated from the intermediate transfer belt 11 (transfer facing roller 13), and the driven rollers 17 b of the two transport roller pairs 17 are respectively driven. The normal paper conveyance path 43 (shown by a thick solid line in the figure), which is separated from the roller 17a and extends from the lower conveyance roller pair 17 to the fixing device 20, is opened. At this time, the operator rotates the sub-rotation unit 64 in the direction to open the refeed path 62 (counterclockwise in the figure), so that the merging portion G (refeed path is moved from the third switching claw 23). The refeed path 62 (shown by a thick dashed line in the drawing) up to the normal paper transport path 43 is opened.

Next, the configuration of the secondary transfer roller 100 as a replacement roller member, which is a characteristic part of the present invention, will be described.
FIG. 1 is an external perspective view showing a secondary transfer roller 100 that can be attached to and detached from the sub-rotation unit 64.
The secondary transfer roller 100 according to this embodiment includes a roller portion 102 made of an elastic body formed on a peripheral surface of a core metal, and a core metal portion that extends outward from both ends of the roller portion in the roller rotation axis direction. It comprises two shaft portions 103. In the present embodiment, the two shaft portions 103 of the secondary transfer roller 100 are provided with a ball bearing (not shown) of a roller mounting portion 104a of the grip portion 104, which is a grip portion as a handle member (see reference numeral 106 in FIG. 9). It is attached so that it can rotate freely. The grip 104 is integrally formed with a transfer outlet guide 101 that is a conveyance guide member as a conveyance regulating member. In this embodiment, the transfer outlet guide 101 also functions as a handle member.

  In the present embodiment, the transfer outlet guide 101 and the grip portion 104 are integrally formed of ABS (acrylonitrile butadiene styrene) resin. The material of the transfer outlet guide 101 and the grip 104 is not limited to ABS resin, but may be other resin such as PC (polycarbonate) resin. However, since a member formed of ABS resin is generally highly flexible, the shaft portion of the secondary transfer roller 100 is less than a resin having low flexibility such as PC (polycarbonate) resin or AS (acrylonitrile styrene) resin. The workability when attaching / detaching the roller attaching portion 104a of the gripping portion 104 to / from the cored bar portion constituting 103 is excellent, and the problem that the roller attaching portion 104a breaks during the work is less likely to occur. . On the other hand, from the viewpoint of the paper guide function of the transfer outlet guide 101, the transfer outlet guide 101 is preferably made of a resin that does not contain a butadiene component. This is because, when the transfer outlet guide 101 is formed of a resin containing a butadiene component, the dielectric constant of the transfer outlet guide 101 increases. As a result, the amount of frictional charge of the transfer outlet guide 101 due to friction with the paper increases, and the unfixed state on the paper. This is because the possibility of disturbing the toner image increases. In the present embodiment, an integrally molded product of the grip portion 104 and the transfer outlet guide 101 is used. However, these may be formed of separate members and fixed to each other.

Further, the shaft portion 103 of the secondary transfer roller 100 extends outward in the roller rotation axis direction of the roller mounting portion 104a, and a cap 105 that is a sliding bearing member serving as a cap-shaped bearing member is provided at the extended portion. Is attached. The cap 105 is clamped and fixed by a clamping member (not shown) as a roller support portion provided in the apparatus main body 50 (specifically, an intermediate transfer unit including the intermediate transfer belt 11), so that the secondary transfer roller Positioning in the vertical direction in the apparatus main body 100 is performed. The cap 105 is formed of a resin such as polyacetal resin having low friction with respect to the outer peripheral surface of the shaft portion 103, and the inner periphery of the cap 105 can be obtained even when the cap 105 is held between the holding members of the apparatus main body 50. There is little friction between the surface and the outer peripheral surface of the cored bar portion, and the secondary transfer roller 100 can be rotated with a low load.

FIG. 5 is an enlarged view showing an end portion of the secondary transfer roller 100. This figure is an enlarged view of the end portion shown on the left side in FIG. 1, and when the secondary transfer roller 100 is mounted on the sub-rotation unit 64, it is viewed from the side facing the sub-rotation unit 64. belongs to.
As shown in the figure, the cap 105 includes a cylindrical cap body 105a into which the shaft portion 103 is inserted, a mark portion 105b indicating a mounting direction when the secondary transfer roller 100 is mounted on the sub-rotation unit 64, and the cap body. The connecting portion 105c extends outward in the radial direction from the outer peripheral surface of 105a and has a mark portion 105b connected to its end. In the present embodiment, as will be described later, the secondary transfer roller 100 is moved downward in the vertical direction to the sub-rotation unit 64 in a posture in which the transfer outlet guide 101 is positioned above the roller portion 102 in the vertical direction. The secondary transfer roller 100 is attached to the sub rotation unit 64. As shown in the drawing, an arrow indicating the mounting direction is formed on the flat portion of the mark portion 105b.

  In the present embodiment, a fixing member that fixes the cap 105 to the roller mounting portion 104 a of the grip portion 104 is provided so that the cap 105 does not easily come off from the shaft portion 103. In the present embodiment, the fixing member includes a connecting portion 105c of the cap 105 as an engaging portion, and a clamping portion 104b as an engaged portion provided on the outer side in the roller rotation axis direction of the roller mounting portion 104a. ing. When the cap 105 is attached to the shaft portion 103 from the outer side in the roller rotation axis direction, the cap connecting portion 105c is clamped by the clamping portion 104b of the roller mounting portion 104a, so that the cap is fixed to the roller mounting portion 104a in a snap-fit manner. Is done.

  In the case of the secondary transfer roller 100 having the above-described configuration, at the time of replacement, whether an operator such as a general user or a serviceman has the two grip portions 104 positioned at both ends of the secondary transfer roller 100 with both hands. The transfer outlet guide 101 is handled with one hand or both hands. The grip portion 104 or the transfer outlet guide 101 is located in a location that is easier for the operator to hold than the roller portion 102 and the shaft portion 103 in the secondary transfer roller 100 and is shaped so as to be easily held. Therefore, most workers handle the secondary transfer roller 100 while holding the grip 104 or the transfer outlet guide 101. As a result, it can be expected that there will be almost no opportunity for the secondary transfer roller 100 to be handled by the operator gripping the roller portion 102 or the shaft portion 103. Therefore, when hand oil adheres to the surface of the roller section 102, the paper transferability by the secondary transfer roller 100 decreases, or the image quality deteriorates due to occurrence of unevenness in the secondary transfer electric field, As will be described later, there is no problem that workability when the roller attachment portion 104a of the grip portion 104 attached to the shaft portion 103 is fitted into the roller receiving portion provided in the sub-rotation unit 64 is deteriorated.

FIG. 6 is an external perspective view showing the sub-rotation unit 64 with the secondary transfer roller 100 mounted. FIG. 6A is a view from the apparatus main body side, and FIG. Viewed from the side.
When the secondary transfer roller 100 according to this embodiment is mounted on the sub-rotation unit 64, the secondary transfer roller 100 is held by the roller receiving portion 70 as a handle holding member provided in the sub-rotation unit 64. The roller mounting portion 104a of the portion 104 is supported. When the double-sided unit 60 is closed with respect to the apparatus main body 50, the second unit 60 in the virtual plane orthogonal to the double-sided unit swinging direction in a state where the double-sided unit 60 is completely closed by guiding the cap 105 of the secondary transfer roller 100 is used. Holding members 19a and 19b as positioning means for positioning the position of the secondary transfer roller 100 are provided in the apparatus main body 50 in correspondence with caps 105 respectively attached to both ends of the secondary transfer roller 100 (FIG. 6 ( In a), only the end on the right side in the figure is shown). The sandwiching members 19a and 19b have a taper shape at the front end portion and a parallel shape with a gap G corresponding to the outer diameter of the cap body 105a of the cap 105 on the rear end side. .

  When the secondary transfer roller 100 is mounted on the sub-rotation unit 64, the sheet guide surface of the transfer exit guide 101 in the secondary transfer roller 100 is the normal sheet transport path 43 when the duplex unit 60 is closed. It is fixed to the sub-rotation unit 64 by a snap fit so as to be in a posture along (see FIG. 4). Further, as shown in FIG. 6A, a transfer inlet guide plate 68 is attached below the secondary transfer roller 100 on the apparatus main body side of the sub-rotation unit 64, and a guide plate (FIG. 2 and FIG. 4 (not shown) but a part of the normal paper conveyance path 43 (see FIG. 4). Further, as shown in FIG. 6 (b), the re-feeding path 62 side of the sub-rotation unit 64 is configured as a conveyance guide surface 69 having a plurality of ribs 69a, and the opposing guide member 66 (FIG. 4). And a part of the refeed path 62.

Next, replacement work when the secondary transfer roller 100 is replaced will be described.
FIG. 7 is an explanatory view showing the movement when the secondary transfer roller 100 is attached to the sub-rotation unit 64.
When replacing the secondary transfer roller 100, first, the operator opens the double-sided unit 60 to expose the sub-rotating unit 64 as shown in FIG. At this time, the secondary transfer roller 100 is fixed to the auxiliary rotation unit 64 by snap fitting as described above. The operator holds the transfer outlet guide 101 or the holding portion 104 and releases the fixation by moving it toward the apparatus main body 50 (in the direction opposite to the direction indicated by the white arrow B in FIG. 7). . Thereby, the secondary transfer roller 100 becomes rotatable in a state where the roller mounting portion of the grip portion 104 is supported by the roller receiving portion of the sub-rotation unit 64. When the secondary transfer roller 100 is rotated until the sheet guide surface of the transfer outlet guide 101 is substantially parallel to the vertical surface, the operator holds the transfer outlet guide 101 or the grip portion 104 while holding the transfer exit guide 101 in the vertical direction. Lift up. As a result, the roller mounting portion of the grip portion 104 is detached from the roller receiving portion of the sub-rotation unit 64, and the secondary transfer roller 100 is detached from the sub-rotation unit 64. After the secondary transfer roller 100 is removed from the sub-rotation unit 64 in this way, a new replacement secondary transfer roller 100 is attached to the sub-rotation unit 64 in the reverse procedure to the above-described removal operation. To do.

  Thereafter, the operator attaches a new replacement secondary transfer roller 100 to the sub-rotation unit 64. Here, when performing the replacement work, the worker generally stands toward the side where the duplex unit 60 of the full-color printer is provided. Therefore, when the operator grips the transfer exit guide 101 or the grip portion 104 of the replacement secondary transfer roller 100, the surface of the secondary transfer roller 100 on the side facing the sub-rotation unit 64 at the time of mounting (see FIG. 1). It will be held as if the back side is seen in front. Then, in a state where the operator holds the transfer exit guide 101 or the grip portion 104 in the replacement secondary transfer roller 100, the roller mounting portion 104a of the grip portion fits into the roller receiving portion of the sub-rotation unit 64. Thus, it attaches with respect to the subrotation unit 64 from the perpendicular direction upper side. At this time, as shown in FIG. 5, the operator sees an arrow indicating the mounting direction formed on the mark portion 105 b, so that the secondary transfer roller 100 may be mounted in the direction of the arrow. I can confirm. In addition, in the present embodiment, since this arrow exists in the vicinity of the roller mounting portion 104a of the gripping portion that fits into the roller receiving portion of the sub-rotation unit 64, it is difficult for the operator to overlook this arrow.

  In particular, in this embodiment, although not shown in the drawings, the position of the arrow of the secondary transfer roller 100 when the roller mounting portion 104a of the gripping portion is properly fitted into the roller receiving portion of the sub-rotation unit 64 is located. An arrow of the same kind is also provided in the vicinity of the roller receiving portion of the sub-rotation unit 64 that is at a position opposite to. Therefore, the operator works so that the secondary transfer roller 100 is mounted on the sub-rotation unit 64 so that the positions of these arrows are in an appropriate positional relationship, so that the roller mounting portion 104a of the gripping portion is moved. The secondary transfer roller 100 can be properly attached to the sub-rotation unit 64 by being fitted into the roller receiving portion of the sub-rotation unit 64. At the time of this work, the worker works along with these arrows while looking at the roller mounting part 104a of the gripping part located at both ends of the secondary transfer roller and the roller receiving part of the sub-rotation unit 64. Therefore, as in the present embodiment, these arrows are positioned close to the roller mounting portion 104a of the gripping portion and the roller receiving portion of the sub-rotation unit 64, so that the operator is less likely to switch the line-of-sight direction. Thus, workability is improved.

FIG. 8 shows an engagement portion between the roller mounting portion 104a of the gripping portion of the secondary transfer roller 100 and the roller receiving portion of the sub-rotation unit 64. FIG. 8A shows the secondary transfer roller 100 removed. FIG. 7B is an enlarged perspective view showing the roller receiving portion 70 of the sub-rotation unit 64 in a state where the secondary transfer roller 64 is in the rotated state of the secondary transfer roller 100 in the roller receiving portion 70 and the roller mounting portion 104a fitted therein. It is explanatory drawing which shows the cross section orthogonal to it.
In the present embodiment, the roller attachment portion 104a of the grip portion 104 attached to the shaft portion 103 of the secondary transfer roller 100 is made of a member having a circular cross section having a diameter R ′ as shown in FIG. Two arc portions are cut so that their strings are parallel to each other. On the other hand, as shown in FIG. 8B, the roller receiving portion 70 provided in the sub-rotation unit 64 has a substantially U-shaped cross-sectional shape with a narrowed opening portion, and the space inside the U-shape is This is a shape obtained by removing a partial arc from a circular cross section having a diameter R slightly larger than the maximum dimension (diameter) R ′ of the roller mounting portion 104a. The opening dimension r of the opening part of the roller receiving part 70 is slightly larger than the minimum dimension r ′, which is the distance between the two strings of the roller mounting part 104a, and is sufficiently smaller than the maximum dimension R ′ of the roller mounting part 104a. Is set. Therefore, the roller mounting portion 104a cannot be fitted into the roller receiving portion 70 unless the roller mounting portion 104a has the posture shown in FIG. 8B with respect to the opening portion of the roller receiving portion 70.

  In this embodiment, when the secondary transfer roller 100 is held so that the sheet guide surface of the transfer outlet guide 101 is substantially parallel to the vertical surface, the roller mounting portion 104a is in the posture shown in FIG. It becomes. When the double-side unit 60 is opened to a predetermined position, the roller receiving portion 70 of the sub-rotation unit 64 is in a posture in which the opening portion is substantially directly above the vertical direction as shown in FIG. 8B. . Therefore, the operator holds the roller with the sheet guide surface of the transfer outlet guide 101 substantially parallel to the vertical surface with respect to the sub-rotation unit 64 of the duplex unit 60 opened to a predetermined position. The secondary transfer roller 100 is attached by moving the secondary transfer roller 100 so that the mounting portion 104a enters the opening portion of the roller receiving portion 70 of the sub-rotation unit 64 from substantially directly above in the vertical direction. The portion 104 a is fitted into the roller receiving portion 70 of the sub-rotation unit 64. Since the maximum dimension R ′ of the roller mounting part 104 a is slightly smaller than the minimum dimension (diameter) R of the internal space of the roller receiving part 70, the roller mounting part 104 a of the secondary transfer roller 100 has the sub-rotation unit 64. The roller receiving portion 70 can be freely rotated. Accordingly, the operator rotates the secondary transfer roller 100 so that the transfer outlet guide 101 moves away from the apparatus main body 50 while holding the transfer outlet guide 101 or the grip portion 104. Then, the secondary transfer roller 100 is snap-fitted and fixed to the sub-rotation unit 64 so that the gripping transfer outlet guide 101 or the grip portion 104 is pressed against the sub-rotation unit 64. Thereafter, the operator closes the duplex unit 60 to complete the mounting operation of the replacement secondary transfer roller 100.

  Here, when the replacement secondary transfer roller 100 is mounted, the operator makes an appropriate positional relationship between the arrow of the secondary transfer roller 100 and the arrow of the sub-rotation unit 64 as described above. Next, the secondary transfer roller 100 is positioned with respect to the sub-rotation unit 64. At this time, if there is no means for assisting the positioning, the worker must perform positioning only with his / her own force, and the workability deteriorates. Therefore, in this embodiment, the following positioning means is provided.

FIG. 9 is an explanatory view showing a cross section orthogonal to the rotation axis direction in a state where the secondary transfer roller 100 is attached to the sub rotation unit 64.
As illustrated, in the present embodiment, guide pieces 104c and 104d are formed at positions adjacent to the inner side and the outer side in the roller rotation axis direction with respect to the roller mounting portion 104a of each gripping portion 104, respectively. These guide pieces 104c and 104d are for assisting the positioning of the secondary transfer roller 100 with respect to the sub-rotation unit 64 in the roller axial direction. Therefore, it is preferable to provide at least the radial direction of the roller rotation shaft from the lower circular arc portion of the roller mounting portion 104a shown in FIG. 8B, and in this embodiment as well. It has been. By providing such guide pieces 104c and 104d, when positioning the secondary transfer roller 100 in the roller axial direction with respect to the sub-rotation unit 64, the operator first needs to guide the guide pieces 104c and 104d. Between 104d, the operation | work which fits the edge part 70a (refer FIG. 8) which forms the opening part of the roller receiving part 70 in the subrotation unit 64 is performed. When the end portion 70a is fitted between the guide pieces 104c and 104d, the secondary transfer roller 100 is positioned with respect to the sub rotation unit 64 in the roller axis direction. Thereafter, the secondary transfer roller 100 is moved in a direction perpendicular to the rotation axis direction, and the roller mounting portion 104 a of the secondary transfer roller 100 is inserted into the opening portion of the roller receiving portion 70.

  As described above, according to the present embodiment, the secondary transfer roller is moved to the roller shaft in the state where the secondary transfer roller 100 is positioned in the roller axis direction with respect to the sub-rotation unit 64 by the guide pieces 104c and 104d. Positioning in a direction orthogonal to the direction can be performed, and the roller mounting portion 104 a can be inserted into the opening portion of the roller receiving portion 70. Therefore, workability is markedly improved as compared with the case where the roller mounting portion 104a is inserted into the opening portion of the roller receiving portion 70 while simultaneously positioning the secondary transfer roller 100 in both the roller axial direction and the direction orthogonal thereto. Rise.

In this embodiment, the case where the guide pieces 104c and 104d are formed on the inner side and the outer side in the roller rotation axis direction for each of the two roller mounting portions 104a has been described. An effect can be obtained.
For example, as shown in FIG. 10, even in the configuration in which guide pieces 104c and 104d are formed on the inner side and the outer side in the roller rotation axis direction with respect to any one of the two roller mounting portions 104a, the workability is the same as in this embodiment. Can be improved.
Further, for example, as shown in FIG. 11, even in the configuration in which the guide piece 104c is formed only on the outer side in the roller rotation axis direction for each of the two roller mounting portions 104a, the workability is improved as in the present embodiment. Can do.
Although not shown, the guide piece 104d may be formed only on the inner side in the roller rotation axis direction for each of the two roller mounting portions 104a.

Next, a replacement part that is packed in order to transport the replacement secondary transfer roller 100 will be described.
FIG. 12 is an explanatory view showing a cross section of the packing member when the replacement part with the secondary transfer roller 100 packed is viewed from the roller axial direction.
This packing member accommodates the secondary transfer roller 100 inside, and an outlet 201a for taking out the secondary transfer roller 100 is formed in a direction perpendicular to the rotation axis direction of the secondary transfer roller 100. A box 201 and a holding member 202 that holds the posture of the secondary transfer roller 100 housed in the housing box 201 so that the grip 104 and the transfer outlet guide 101 face the outlet 201a.

The storage box 201 has a rectangular parallelepiped shape that is long in a direction corresponding to the axial direction of the secondary transfer roller 100, and includes a lid portion 201b that can open and close the outlet 201a. As a material for the storage box 201, a wide variety of storage boxes can be used. In the present embodiment, the container 201 is formed by cutting and folding a plate-shaped cardboard material into a shape as illustrated.
The holding member 202 includes a roller holding portion 202 a that holds the lower portion of the roller portion 102 of the secondary transfer roller 100, and the transfer outlet guide 101 so that the transfer outlet guide 101 of the secondary transfer roller 100 faces substantially the outlet side. It is comprised from the guide holding | maintenance part 202b which controls a motion. A wide variety of known materials can be used for the holding member 202. In the present embodiment, the holding member 202 is formed by cutting and folding a plate-shaped cardboard material into a shape as illustrated.

  When taking out the secondary transfer roller 100 from such a packing member, the worker first opens the cover 201 of the storage box 201 and opens the outlet 201a. At this time, in the present embodiment, the transfer outlet guide 101 and the grip portion 104 of the secondary transfer roller 100 are held by the guide holding portion 202b of the holding member 202 so as to face the take-out port 201a. Therefore, the operator can easily take out the secondary transfer roller 100 from the storage box 201 by simply putting his / her hand from the take-out port 201 a, holding the transfer exit guide 101 and the grip portion 104 and pulling them up. Moreover, according to the present embodiment, the secondary transfer roller 100 is held in the sub-rotation unit of the duplex unit while holding the transfer outlet guide 101 and the grip 104 that are gripped when the secondary transfer roller 100 is taken out from the storage box 201. Since the secondary transfer roller 100 is taken out from the storage box 201 and mounted on the sub-rotation unit 64, the secondary transfer roller 100 does not need to be changed and the workability is high.

As described above, the full-color printer of this embodiment includes the secondary transfer roller 100 as a roller member that can be attached to and detached from the printer main body, and the shaft portion 103 of the secondary transfer roller 100 provided as a bearing member. And an nipping member 19a, 19b as a roller support portion supported via a cap 105 as an image forming apparatus for forming an image on a sheet of recording material. The secondary transfer roller 100 includes a roller portion 102 and two shaft portions 103 that extend outward from the both ends of the roller portion 102 in the roller rotation axis direction and rotate with respect to the two shaft portions 103. It has a grip portion 104 and a transfer outlet guide 101 as handle members provided movably. As a result, most of the workers who perform replacement work of the secondary transfer roller handle the secondary transfer roller 100 by gripping the grip portion 104 or the transfer outlet guide 101. As a result, the problem is that hand oil adheres to the surface of the roller portion 102, thereby reducing the paper transportability by the secondary transfer roller 100, or causing unevenness in the secondary transfer electric field and degrading the image quality. There is no problem that workability is deteriorated when the roller attachment portion 104a of the grip portion 104 attached to the shaft portion 103 is fitted into the roller receiving portion provided in the sub-rotation unit 64.
In the present embodiment, the grip 104 and the transfer outlet guide 101 that function as a handle member are a single member that is provided so as to be rotatable with respect to the two shafts 103. If a handle member is individually provided for each shaft portion 103, each handle member can rotate independently with respect to the shaft portion 103, so that the rotation positions of both handle members relative to the shaft portion 103 are relatively shifted. Therefore, it becomes difficult for the operator to grip each handle member. On the other hand, according to the configuration of the present embodiment, such a situation does not occur, so that the operator can easily grasp the grip portion 104 and the transfer outlet guide 101, and the handling property is good.
Further, in the present embodiment, the roller member to be replaced is used for conveying a sheet by contacting one side of the sheet when mounted on the printer main body, specifically, the sub-rotation unit 64 of the duplex unit 60. It is used as a secondary transfer roller 100 that is a transport roller. Then, when the secondary transfer roller 100 is attached to the printer main body , a transfer outlet guide 101 serving as a conveyance guide member that regulates the conveyance direction of the sheet by contacting the sheet being conveyed is provided. And used as a handle member of the secondary transfer roller 100. Normally, the handle member of the secondary transfer roller 100 is a member that is irrelevant to the image forming operation of the full-color printer, so it must be made as small as possible from the viewpoint of downsizing the printer. However, if the handle member is small, the handleability when an operator who performs the replacement work handles the secondary transfer roller 100 correspondingly decreases. As in the present embodiment, when the secondary transfer roller 100 is mounted, the handle member of the secondary transfer roller 100 is used as the transfer outlet guide 101 that inevitably increases in size, thereby reducing the size of the printer. And the handleability of the secondary transfer roller 100 can be made compatible. In this embodiment, the case where the transport roller to be replaced is the secondary transfer roller 100 has been described. However, another transport roller may be used, and the transport roller may be a driving roller or a driven roller.
In this embodiment, since the transfer outlet guide 101 is made of ABS resin, it is excellent in workability when handling it as described above, and it is difficult to cause a problem that it breaks during the work.
As described in the above embodiment, the transfer outlet guide 101 is preferably formed of a resin that does not contain a butadiene component from the viewpoint of the paper guide function of the transfer outlet guide 101.

The secondary transfer roller 100 of the present embodiment is a sliding bearing member as a cap-like bearing member to the outer peripheral surface and the sliding of the shaft portion 103 to at least one of the shaft portion 103 of the two shaft portions 103 A cap 105 is attached. The cap 105 is fixed to the holding members 19a and 19b of the printer main body when the secondary transfer roller 100 is attached to the printer main body. Further, the secondary transfer roller 100 includes fixing members 104 b and 105 c that fix the cap 105 to the roller mounting portion 104 a of the grip portion 104. With such a configuration, the cap 105 can be prevented from being easily detached from the shaft portion 103.
Further, in this embodiment, since the cap 105 is a resin member having an inner peripheral surface that slides with the shaft portion 103 with low friction, the cap that rotates smoothly with respect to the shaft portion 103 can be configured at low cost.
Further, the fixing member in the present embodiment is provided on the outer side in the roller rotation axis direction of the connecting portion 105c as an engaging portion protruding radially outward from the outer peripheral surface of the cap 105 and the roller mounting portion 104a in the grip portion 104. The engaging portion 104b as the engaged portion is configured such that when the connecting portion 105c enters the holding portion 104b from the outside in the roller rotation axis direction, the connecting portion 105c is held by the holding portion 104b. . With such a configuration, the operator can attach the cap 105 to the shaft portion 103 by a simple operation of fitting the coupling portion 105c of the cap 105 into the clamping portion 104b from the outside in the roller rotation axis direction. The manufacturing process of the transfer roller 100 can be simplified to increase productivity. It is to be noted that the same effect can be obtained by providing a holding portion which is an engaged portion on the cap 105 side and providing an engaging portion to be held on the roller attachment portion 104a side.
As shown in FIG. 13, if the fixing member is constituted by a screwing member 107 that screws the cap 105 and the roller mounting portion 104 a of the gripping portion 104, the cap 105 is not surely detached from the shaft portion 103. You can do that.
In the present embodiment, the cap 105 has a mark portion 105b that indicates a mounting direction when the secondary transfer roller 100 is mounted on the printer body. Thus, it is possible to hardly occur a situation in which the workers would be fitted in the specified mounting direction, it is possible to improve the workability of the replacement work.
In particular, in the present embodiment, when the secondary transfer roller 100 is mounted on the printer body, another mark portion is provided at a location on the printer body side corresponding to the mark portion 105b provided on the cap 105 of the secondary transfer roller 100. Therefore, the mark portion 105b of the cap 105 also functions as a mark portion indicating a mounting position when the secondary transfer roller 100 is mounted on the printer main body. The presence of such a marker portion 105b, the operator can hardly occurs a situation in which would be fitted in the specified mounting position, it is possible to improve the workability of the replacement work.
As shown in FIG. 14, if the arrow pointing inward in the roller axial direction is used as a mark formed on the mark part 105b as the mark part indicating the mounting position, it is effective for the operator to mistake the mounting position. Therefore, the workability of the replacement work can be further improved.

In the present embodiment, the secondary transfer roller 100 is supported by the printer main body by holding the cap that is rotatable by sliding with respect to the shaft portion 103 by the holding members 19a and 19b on the printer main body side. Although described, other configurations may be used.
For example, as shown in FIG. 15, instead of the cap 105, the inner peripheral surface side is attached to at least one of the two shaft portions 103, and the secondary transfer roller 100 is attached to the printer main body. In this case, a bearing member 108 made of a ball bearing whose outer peripheral surface side is fixed to the clamping members 19a and 19b of the printer main body may be used. In this case, the rotational load between the shaft portion 103 and the clamping members 19a and 19b can be further reduced, so that the secondary transfer roller 100 mounted on the printer body can be rotated more smoothly.
In the example shown in FIG. 15, since the bearing member 108 is attached to the shaft portion 103 by press-fitting, the workability when the bearing member 108 is attached to the shaft portion 103 is improved, and the secondary transfer roller 100 productivity can be increased.
Also, as shown in FIG. 16, a cylindrical collar member (cylindrical member opened only at one end surface on the front side in the figure) 109 attached from the outside in the roller axial direction to the outer surface of the bearing member 108 is provided. A fixing member for fixing the collar member 109 to the roller mounting portion 104a of the grip portion 104 is provided. Although the collar member 109 has the same configuration as the cap 105 in the above-described embodiment although the inner diameter is different, the fixing member protrudes radially outward from the outer peripheral surface of the collar member 109 as in the above-described embodiment. The connecting portion 109c as the engaging portion and the clamping portion 104b as the engaged portion provided on the outer side in the roller rotation axis direction of the roller mounting portion 104a in the grip portion 104 are connected from the outside in the roller rotation axis direction. A configuration in which the connecting portion 109c is held by the holding portion 104b when the portion 109c enters the holding portion 104b can be employed. With the configuration shown in FIG. 16, the bearing member 108 is mounted inside the collar member 109, and the shaft portion 103 is inserted into the inner circumferential space of the bearing member 108 in this state to connect the connecting portion 109 b of the collar member 109. The bearing member 108 can be attached to the shaft portion 103 by an operation of fitting into the holding portion 104b of the roller attachment portion 104a. This operation is simpler than the case where the bearing member 108 is press-fitted and fixed to the shaft portion 103, and the productivity of the secondary transfer roller 100 can be further increased.
Similarly to the example shown in FIG. 13, if the fixing member is constituted by a screwing member for screwing the collar member 109 and the roller mounting portion 104 a of the grip portion 104, the color member 109 is a secondary transfer roller. It can be ensured that it does not deviate from 100.

  In addition, the replacement part in the present embodiment includes the secondary transfer roller 100 having the above-described configuration, and an outlet 201a for accommodating the secondary transfer roller 100 and taking out the secondary transfer roller 100 is a secondary transfer roller. The storage box 201 formed in a direction orthogonal to the rotation axis direction of the roller 100 and the attitude of the secondary transfer roller 100 stored in the storage box 201 are determined by the grip portion 104 of the secondary transfer roller 100 or the transfer outlet. And a holding member 202 that holds the guide 101 so as to face the outlet 201a. Thereby, most of the workers who take out the secondary transfer roller 100 from the storage box 201 hold the grip portion 104 or the transfer outlet guide 101 and take out the secondary transfer roller 100 from the storage box 201. As a result, during this extraction operation, hand oil adheres to the surface of the roller portion 102, so that the paper transferability by the secondary transfer roller 100 is reduced, or unevenness of the secondary transfer electric field occurs, resulting in image quality. There is no problem such as deterioration or workability when the roller mounting portion 104a of the grip portion 104 attached to the shaft portion 103 is fitted into the roller receiving portion provided in the sub-rotation unit 64. .

Further, the full color printer of this embodiment is provided with a roller receiving portion 70 as a handle holding member for holding the grip portion 104 or the transfer outlet guide 101 of the secondary transfer roller 100 in the printer body, and the secondary transfer roller 100. As shown in FIG. 8 (b), the holding portion 104 has portions R ′ and r ′ having different lengths in the direction perpendicular to the roller axial direction, and is held by the roller receiving portion 70. A roller mounting portion 104a is provided as a portion. The roller receiving portion 70 has an opening portion as a receiving port having a dimension corresponding to the shortest portion r ′ in the direction orthogonal to the roller axial direction in the roller mounting portion 104a. Accordingly, if the roller mounting portion 104a does not have the posture shown in FIG. 8B with respect to the opening portion of the roller receiving portion 70, the roller mounting portion 104a cannot be fitted into the roller receiving portion 70, and the secondary The transfer roller 100 cannot be mounted on the sub-rotation unit 64. By restricting the mounting of the secondary transfer roller 100 in this way, it is possible to effectively prevent the secondary transfer roller 100 from being mounted in an incorrect posture with respect to the sub-rotation unit 64.
In the present embodiment, the roller attachment portion 104 a is an attachment portion of the grip portion 104 to the two shaft portions 103 on the outer side in the roller axis direction of the roller portion 102 of the secondary transfer roller 100. Then, the roller mounting portion 104a is adjacent to the inner side or the outer side in the roller axial direction, and when the roller mounting portion 104a is inserted into the opening portion of the roller receiving portion 70, an end forming the opening portion in the roller receiving portion 70 is formed. Guide pieces 104c and 104d are provided as guide members that guide the insertion of the roller mounting portion 104a into the opening by contacting the inside or outside of the portion 70a in the roller axial direction. Thus, the secondary transfer roller 100 is positioned in the direction orthogonal to the roller axis direction in a state where the secondary transfer roller 100 is positioned in the roller axis direction with respect to the sub-rotation unit 64 by the guide pieces 104c and 104d. The roller mounting portion 104a can be inserted into the opening portion of the roller receiving portion 70 by positioning. Therefore, workability is markedly improved as compared with the case where the roller mounting portion 104a is inserted into the opening portion of the roller receiving portion 70 while simultaneously positioning the secondary transfer roller 100 in both the roller axial direction and the direction orthogonal thereto. Rise.
The full-color printer of this embodiment includes a double-sided unit 60 as an open / close door that opens vertically on the side of the printer body, and a link mechanism as a door posture holding member that holds the double-sided unit 60 in an open posture. The roller receiver 70 is arranged on the inner surface of the printer main body of the duplex unit 60 so that the opening portion of the roller receiver 70 faces substantially vertically upward when the duplex unit 60 is open by the link mechanism. Provided. In general, since the cored bar portion is the heaviest in the secondary transfer roller 100, when the secondary transfer roller 100 is held by gripping the grip portion 104 or the transfer outlet guide 101, the roller portion 102 is at the lowest position in the vertical direction. It is possible to use such a posture with the least force. Therefore, according to the full color printer, less force is required to attach the secondary transfer roller 100 to the sub-rotation unit 64.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 10M, 10C, 10Y, 10Bk Image forming unit 11 Intermediate transfer belt 19a, 19b Holding member 50 Apparatus main body 60 Duplex unit 64 Subrotation unit 70 Roller receiving part 100 Secondary transfer roller 101 Transfer exit guide 102 Roller part DESCRIPTION OF SYMBOLS 103 Shaft part 104 Holding part 104a Roller attaching part 104b Clamping part 104c, 104d Guide piece 105 Cap 105a Cap main body 105b Marking part 105c Connection part 107 Screwing member 108 Bearing member 109 Color member 201 Storage box 201a Outlet 201b Cover part 202 Holding Member 202a Roller holding part 202b Guide holding part

JP 2002-258635 A

Claims (11)

In an image forming apparatus that includes an exchangeable roller member for an image forming apparatus main body and forms an image on a sheet,
The roller member is
A shaft portion having a rotation shaft at the center and having two shaft end portions;
A roller portion having two roller end portions and covering the shaft portion along the rotation axis so that the two shaft end portions protrude from the roller end portion toward the outer side in the rotation axis direction;
Two roller mounting portions provided at the two shaft end portions;
A transport guide member that guides the paper being transported and is rotatable relative to the shaft end ;
A cylindrical portion into which the shaft end portion is inserted, and at least one sliding bearing member attached to at least one shaft end portion of the two shaft end portions;
An engaging portion provided to project radially outward from the outer surface of the cylindrical portion of the sliding bearing member;
When the sliding bearing member is inserted into the shaft end along the rotation shaft, the engagement member is provided on at least one of the two roller mounting portions along the rotation shaft. have a and the engaged portion for engaging portion engages,
The engaged portion has a pair of engaged portions provided at a distance from each other when viewed from the rotation axis direction,
The at least one sliding bearing member is inserted into the cylindrical portion from the outer side in the axial direction of the roller, so that the engaging portion enters between the pair of engaged portions, and the roller An image forming apparatus, wherein rotation with respect to the attachment portion is restricted . The image forming apparatus 請 Motomeko 1,
The image forming apparatus according to claim 1, wherein the engaged portion is a clamping portion that clamps a circumferential surface of the engaging portion from a roller radial direction. The image forming apparatus according to claim 2 .
When the sliding bearing member is inserted into the shaft end along the rotating shaft, the clamping portion clamps the engaging portion , so that the sliding bearing member has the at least one of the sliding bearings. An image forming apparatus fixed to a roller mounting portion. The image forming apparatus according to any one of claims 1 to 3 ,
The image forming apparatus, wherein the roller mounting portion and the conveyance guide member are integrally formed. The image forming apparatus according to any one of claims 1 to 3 ,
The image forming apparatus, wherein the roller mounting portion and the transport guide member are formed of separate members. The image forming apparatus according to any one of claims 1 to 5 ,
The image forming apparatus, wherein the sliding bearing member is made of a resin having low friction with respect to an outer peripheral surface of the shaft end portion. The image forming apparatus according to any one of claims 1 to 6 ,
An image forming apparatus comprising: a grip member for gripping when an operator handles the roller member outside the transport guide member in the rotation axis direction. The image forming apparatus according to any one of claims 1 to 7 ,
There are two sliding bearing members, and each sliding bearing member is attached to each of the two shaft end portions at a position on the outer side in the rotation axis direction of the roller mounting portion,
And the engaging portion and the engaged portion is a two respectively, each of the engagement portion, the image forming apparatus characterized by along the rotation axis is provided in each of the above roller mounting portion. The image forming apparatus according to any one of claims 1 to 8 ,
The image forming apparatus, wherein the roller attaching portion is attached to the shaft end portion via a ball bearing. The image forming apparatus according to any one of claims 1 to 9 ,
A rotation unit that is rotatable with respect to the image forming apparatus main body;
The image forming apparatus, wherein the roller member is detachable from the rotating unit. The image forming apparatus according to claim 10 .
A clamping member is provided in the image forming apparatus main body,
When the roller member is mounted on the rotating unit and the rotating unit is rotated in order to mount the roller member on the image forming apparatus main body, the sliding bearing member of the roller member becomes the clamping member. An image forming apparatus that is sandwiched.

Images