Image forming apparatus

Abstract

To miniaturize a device while improving workability when attaching / detaching an attachment / detachment unit.SOLUTION: An image forming apparatus that forms an image on a sheet, the image forming apparatus comprising: an apparatus main body having an opening; a detachable unit that is detachable from the apparatus main body through the opening; and an openable and closable member that is openably and closably supported by the apparatus main body. And a connecting member connected to the door so as to move in conjunction with the door, wherein in a state where the door is located at the open position, the connecting member is movable from a first position where the connecting member overlaps with an attachment / detachment trajectory of the attaching and detaching unit to a second position where the connecting member does not overlap with the attachment / detachment trajectory of the attaching and detaching unit and allows the attaching and detaching unit to be attached to and detached from the apparatus main body.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that forms an image on a sheet. [Background technology]

[0002] Patent Document 1 discloses an image forming apparatus equipped with a door that can be opened and closed relative to the main body of the apparatus, and a strap that connects the main body of the apparatus to the door. The strap regulates the opening angle of the door when the door is open, and is positioned outside the attachment and detachment path of a replaceable intermediate transfer unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-4800 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the strap in Patent Document 1 is positioned outside the attachment / detachment trajectory of the intermediate transfer unit so as not to restrict attachment / detachment of the intermediate transfer unit, which restricts the miniaturization of the image forming apparatus.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an image forming apparatus that can be made compact while improving the ease of attachment and detachment of a detachable unit. [Means for solving the problem]

[0006] One aspect of the present invention is an image forming apparatus that forms an image on a sheet, comprising: an apparatus main body having an opening; a detachable unit that is attached to and detached from the apparatus main body through the opening; a door that is supported on the apparatus main body so as to be openable and closable and that is movable between a closed position that closes the opening and an open position that opens the opening; and a connecting member that is connected to the door so as to interlock with the door, wherein when the door is positioned in the open position, the connecting member is movable from a first position that overlaps with the attachment / detachment trajectory of the detachable unit to a second position that does not overlap with the attachment / detachment trajectory of the detachable unit and allows the detachable unit to be attached to and detached from the apparatus main body. [Effects of the Invention]

[0007] According to the present invention, the device can be made smaller while improving the workability when attaching and detaching the detachable unit. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic view showing an entire printer according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing the printer with the rear door open. [Figure 3] 3(a) is a rear view showing the inside of the printer with the rear door open, and FIG. 3(b) is an enlarged perspective view showing the dashed line area D in FIG. 3(a). [Figure 4] 1A is a cross-sectional view showing the peripheral configuration of one end of the holding member, and FIG. 1B is a cross-sectional view showing the state in which the connection of one end of the holding member is released. [Figure 5] FIG. 4 is a perspective view showing a state in which the fixing device is removed from the main body of the apparatus. [Figure 6] FIG. 10 is a perspective view showing a printer according to a first modified example of the first embodiment. [Figure 7] FIG. 10 is a perspective view showing a printer according to a second modification of the first embodiment. [Figure 8] FIG. 11 is a rear view showing a printer according to a third modified example of the first embodiment. [Figure 9] FIG. 11 is a rear view showing a printer according to a fourth modified example of the first embodiment. [Figure 10] 10A is a perspective view showing a printer according to a fifth modified example of the first embodiment, and FIG. 10B is a rear view showing the printer. [Figure 11] 10A is a perspective view showing a printer according to a sixth modified example of the first embodiment, and FIG. 10B is a rear view showing the printer. [Figure 12] FIG. 10 is a perspective view showing a printer according to a second embodiment. [Figure 13] Rear view of the printer with the rear door open. [Figure 14] FIG. [Figure 15] 15A is an enlarged perspective view showing the dashed line portion N in FIG. 14, and FIG. 15B is a cross-sectional view of the dashed line portion N in FIG. [Figure 16] FIG. 15 is an enlarged perspective view of the dashed line portion P in FIG. 14. [Figure 17] 1A is a cross-sectional view showing the tab of the guide member engaging with the boss of the rear door, and FIG. 1B is a cross-sectional view showing the tab of the guide member separating from the boss of the rear door. [Figure 18] FIG. 10 is a perspective view showing a state in which the guide member is removed from the rear door. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment [Overall structure] First, a first embodiment of the present invention will be described. Printer 1, which serves as an image forming apparatus, is an electrophotographic laser beam printer that forms monochrome toner images. As shown in FIG. 1, printer 1 has a sheet feeding section 50 that feeds stacked sheets, and an image forming section 60 that forms images on the fed sheets. Printer 1 also has a fixing device 11 as a fixing unit that fixes images transferred to sheets, and a discharge section 70 that can discharge sheets to a discharge tray 13. Note that the sheets include paper such as paper sheets and envelopes, plastic films such as overhead projector sheets (OHP), cloth, etc.

[0010] When an image formation command is output to the printer 1, an image formation process is started by the image forming unit 60 based on image information input from an external computer or the like connected to the printer 1. The image forming unit 60 has a process cartridge 2, a laser scanner 3, and a transfer roller 4. The process cartridge 2 has a photosensitive drum 2a that rotates in the direction of arrow A, a charging roller 2b, a developing roller 2c, and a cleaning blade 2e that are arranged along the photosensitive drum 2a, a toner container 2d, and a waste toner container 2f. The process cartridge 2 is detachably attached to the device main body 1A of the printer 1.

[0011] The laser scanner 3 irradiates the photosensitive drum 2a with laser light based on the input image information. At this time, the photosensitive drum 2a is pre-charged by the charging roller 2b, and an electrostatic latent image is formed on the photosensitive drum 2a by the irradiation of the laser light. Thereafter, this electrostatic latent image is developed by the developing roller 2c, and a monochrome toner image is formed on the photosensitive drum 2a.

[0012] In parallel with the image formation process described above, sheets S are fed from a sheet feeding section 50. The sheet feeding section 50 has a cassette 5 that is supported in a direction perpendicular to the feeding direction of the sheets S so that it can be attached to and removed from the apparatus main body 1A, and the cassette 5 supports a middle plate 5a that supports the sheets S so that it can be raised and lowered. The middle plate 5a is raised and lowered by the rotation of a lift-up plate 5b driven by a drive source (not shown). The sheets S supported on the middle plate 5a are fed by a pickup roller 6, and the sheets S fed by the pickup roller 6 are separated one by one by a feed roller 7 and a separation roller 8 that is in pressure contact with the feed roller 7.

[0013] The separation roller 8 has a built-in torque limiter, and a limit value of the torque limiter is set so that when one sheet is conveyed to the separation nip formed by the feed roller 7 and the separation roller 8, the separation roller 8 rotates in accordance with the feed roller 7. When multiple sheets are conveyed to the separation nip, the separation roller 8 stops without rotating in accordance with the feed roller 7. Note that a drive force may be input to the separation roller 8 so that the sheet is conveyed in the opposite direction to the sheet conveying direction by the feed roller 7. In addition, although only one cassette 5 is provided in this embodiment, multiple cassettes capable of supporting sheets of different sizes may be provided, and sheets may be fed from these multiple cassettes according to a sheet size selected from the multiple cassettes.

[0014] The sheets S, separated one by one by the feed roller 7 and the separation roller 8, are transported by a transport roller pair 9 to a registration roller pair 10, which corrects any skew. The toner image on the photosensitive drum 2a is transferred onto the sheet S transported at a predetermined transport timing by the registration roller pair 10 by the electrostatic load bias applied to the transfer roller 4. Residual toner remaining on the photosensitive drum 2a is collected into a waste toner container 2f by a cleaning blade 2e.

[0015] The sheet S onto which the toner image has been transferred is subjected to predetermined heat and pressure by the heating roller 11e and pressure roller 11f of the fixing device 11, thereby melting and fixing (fixing) the toner. After passing through the fixing device 11, the sheet S is conveyed to the discharge section 70 by the conveying roller pair 11c. The discharge section 70 is a triplet of rollers consisting of a drive roller 71, a first driven roller 72, and a second driven roller 73. The drive roller 71 is driven by a drive source (not shown), and the first driven roller 72 and the second driven roller 73 are rotated by the drive roller 71. The drive roller 71 and the first driven roller 72 form a first nip 12, and the drive roller 71 and the second driven roller 73 form a second nip 15. The sheet S conveyed by the conveying roller pair 11c is discharged to the discharge tray 13 by the first nip 12.

[0016] Furthermore, when images are formed on both sides of the sheet S, the sheet S conveyed by the conveying roller pair 11c is guided to the second nip 15 by the rotatable guide member 14. The sheet S is then conveyed to the outside of the apparatus main body 1A by the second nip 15, and when the trailing edge of the sheet S passes the guide member 14, the drive roller 71 rotates in the reverse direction. As a result, the sheet S is conveyed toward the inside of the apparatus main body 1A by the second nip 15 and is guided to the double-sided conveying path 16 by the guide member 14.

[0017] The sheet S guided to the double-sided conveying path 16 is conveyed to the registration roller pair 10 by conveying roller pairs 17, 18, and 19. Then, in the same way as when an image is formed on the first side of the sheet S, an image is also formed on the second side opposite to the first side by the image forming section 60 and the fixing device 11. The sheet S with images formed on both sides is discharged to the discharge tray 13 by the first nip 12 of the discharge section 70.

[0018] [Rear door peripheral configuration] Next, the peripheral configuration of the rear door 20 will be described with reference to Figures 1 to 3(b). Figure 2 is a perspective view showing the printer 1 with the rear door 20 open. Figure 3(a) is a rear view showing the interior of the printer 1 with the rear door 20 open, and Figure 3(b) is an enlarged perspective view showing the dashed line area D in Figure 3(a). In Figure 3(a), the outer frame of the fixing device 11 is conveniently shown with a thick line so that the area occupied by the fixing device 11 can be easily seen.

[0019] 1 and 2, the printer 1 has a rear door 20 that is supported on the device main body 1A so that it can be opened and closed (rotated). The rear door 20 is located at the upstream end of the printer 1 in the direction D1 in which the cassette 5 is pulled out, and forms part of the exterior of the printer 1. In other words, when the side from which the cassette 5 is pulled out is considered the front side of the printer 1, the rear door 20 is located on the rear side of the printer 1, opposite the front side.

[0020] As shown in FIG. 2, the device main body 1A has an opening 80, and the rear door 20 is movable between a closed position (position shown in FIG. 1) in which the opening 80 is closed and an open position (position shown in FIG. 2) in which the opening 80 is opened.

[0021] The apparatus main body 1A and the rear door 20 are connected by a pair of holding members 21, 22. More specifically, the holding member 21 has one end 21F connected to the apparatus main body 1A and the other end 21S connected to the rear door 20. Similarly, the holding member 22 has one end 22F connected to the apparatus main body 1A and the other end 22S connected to the rear door 20. It can be said that the holding members 21, 22 as connecting members are connected to the rear door 20 so as to move in conjunction with the rear door 20.

[0022] In this embodiment, the holding members 21 and 22 are made of flat bands made of polypropylene resin and are flexible. That is, when the rear door 20 is in the closed position, the holding members 21 and 22 are curved and accommodated inside the apparatus main body 1A. On the other hand, when the rear door 20 is in the open position, the holding members 21 and 22 extend linearly outside the apparatus main body 1A as shown in FIG. 2, and hold the rear door 20 in the open position. In other words, the holding members 21 and 22 regulate the opening angle of the rear door 20.

[0023] The holding members 21 and 22 are not limited to the above-described forms. For example, the holding members 21 and 22 may be made of a wire or other linear material, or may be made of a member equipped with a damper for attenuating the impact when the rear door 20 is opened. Furthermore, the holding members 21 and 22 may be made of an arm that slides along the rear door 20 when the rear door 20 is opened or closed. In other words, the holding members 21 and 22 may be configured so as not to bend when the rear door 20 is opened or closed.

[0024] 2 and 3(a), the device body 1A of the printer 1 has housings 23 and 24. The housing 23 is disposed at one end of the printer 1 in the width direction W perpendicular to the sheet conveying direction, and the housing 24 is disposed at the other end of the printer 1. One ends 21F and 22F of the holding members 21 and 22 are connected to the housings 23 and 24, respectively.

[0025] The fixing device 11 as a detachable unit is configured to be detachably attached to the apparatus main body 1A through the opening 80, and as shown in FIG. 3(a), one end (dashed line portion B) and the other end (dashed line portion C) in the width direction W overlap with the holding members 21 and 22, respectively. The fixing device 11 is configured to be detachably attached to the apparatus main body 1A in an attachment / detachment direction AD that is substantially parallel to the horizontal direction shown in FIG. 2, and the trajectory of the fixing device 11 when it is attached or detached in the attachment / detachment direction AD is defined as the attachment / detachment trajectory. As shown in FIG. 3(a), the holding members 21 and 22 overlap with the attachment / detachment trajectory of the fixing device 11 when viewed in the attachment / detachment direction AD. The attachment / detachment trajectory of the fixing device 11 is the area within the bold line in FIG. 3(a) extending in the direction of the paper.

[0026] In this state, when the fixing device 11 is attached to or detached from the apparatus main body 1A, it interferes with the holding members 21 and 22. In other words, the holding members 21 and 22 function as limiting members that restrict replacement of the fixing device 11. On the other hand, by arranging the holding members 21 and 22 so that they overlap the attachment / detachment trajectory of the fixing device 11 in this way, the printer 1 can be made smaller in size in the width direction W.

[0027] [How to install and remove the fixing unit] Next, a method for attaching and detaching the fixing device 11 will be described with reference to Figures 3(a) to 5. Figure 4(a) is a cross-sectional view showing the peripheral configuration of one end 21F of the holding member 21, and Figure 4(b) is a cross-sectional view showing how the connection of one end 21F of the holding member 21 is released. Figure 5 is a perspective view showing how the fixing device 11 is removed from the apparatus main body 1A.

[0028] 3(b) and 4(a), the housing 23 of the device main body 1A is provided with a claw portion 23a and a restricting wall 23b, and a hole portion 21a is provided at one end 21F of the holding member 21. The restricting wall 23b prevents the one end 21F of the holding member 21 from rising up toward the front from the housing 23. The holding member 21 is connected to the housing 23 (device main body 1A) by the hole portion 21a at the one end 21F engaging with the claw portion 23a.

[0029] As shown in Fig. 4(a), a space E into which an operator can insert a finger is provided between the holding member 21 and the housing 23. The operator can insert a finger into the space E and pull the tip 21b of one end 21F of the holding member 21 toward the operator, thereby deforming the one end 21F in the direction of the arrow F. By deforming the one end 21F in the direction of the arrow F, the engagement between the hole 21a and the claw 23a is released, as shown in Fig. 4(b).

[0030] Thereafter, the operator moves the holding member 21 in the direction of arrow G1 along the direction of gravity, causing the holding member 21 to pass through the restricting wall 23b. This separates the holding member 21 from the housing 23, and the connection between the holding member 21 and the housing 23 (the apparatus main body 1A) is released.

[0031] The above-described structure for connecting and disconnecting one end 21F of holding member 21 to housing 23 is also provided in holding member 22 and housing 24. When fixing device 11 is attached or detached, holding member 22 is also disconnected from housing 24 (apparatus main body 1A).

[0032] By performing the above operations, one end 21F of holding member 21 and one end 22F of holding member 22 become movable, and as shown in FIG. 5, holding members 21 and 22 can be moved to positions that do not overlap the attachment / detachment trajectory of fixing device 11. That is, holding members 21 and 22 are configured to be movable from a first position (position shown in FIG. 2) that overlaps the attachment / detachment trajectory of fixing device 11 to a second position (position shown in FIG. 5) that does not overlap the attachment / detachment trajectory of fixing device 11 when rear door 20 is in the open position. Furthermore, holding members 21 and 22 become movable from the first position to the second position by releasing the connection between one end 21F and 22F and apparatus main body 1A. Then, holding members 21 and 22 at the second position allow fixing device 11 to be attached to or detached from apparatus main body 1A.

[0033] As shown in FIG. 5, the fixing device 11 is fixed to the apparatus main body 1A by screws 11a, 11b, 11c, and 11d. The screws 11a, 11b, 11c, and 11d are fasteners that can be removed without using tools, and are formed, for example, by knob bolts. After removing these four screws 11a to 11d, an operator can remove the fixing device 11 in a removal direction parallel to the attachment / detachment direction AD (see FIG. 2). In this embodiment, the screws 11a to 11d are designed not to separate from the fixing device 11 to prevent them from being lost. The fixing device 11 can be attached to the apparatus main body 1A by performing the reverse of the above-described removal procedure for the fixing device 11.

[0034] As described above, the holding members 21 and 22 of this embodiment are configured to be movable from a first position (the position shown in FIG. 2) to a second position (the position shown in FIG. 5) that does not overlap the attachment / detachment trajectory of the fixing device 11. Because the holding members 21 and 22 overlap the attachment / detachment trajectory of the fixing device 11 at the first position, the printer 1 can be made smaller in the width direction W. Furthermore, the holding members 21 and 22 can be moved to the second position by releasing the connection between the one ends 21F and 22F and the device main body 1A, and in this state the fixing device 11 can be attached to or detached from the device main body 1A. This ensures good operability when attaching or detaching the fixing device 11.

[0035] Furthermore, one ends 21F, 22F of the holding members 21, 22 can be easily disconnected from the apparatus main body 1A simply by releasing the engagement between the claw portion 23a and the hole portion 21a, thereby improving the workability when attaching and detaching the fixing device 11. Furthermore, because the holding members 21, 22 are made of flexible bands, they are folded when the rear door 20 is in the closed position, reducing the volume they occupy, thereby enabling the printer 1 to be made smaller and less expensive.

[0036] <Modification of the first embodiment> Next, a modified example of the first embodiment will be described with reference to Figures 6 to 11(b). Figure 6 is a perspective view showing a printer 1M1 according to a modified example 1 of the first embodiment. In the first embodiment described above, the holding members 21 and 22 are moved to the second position by releasing the connection between the one ends 21F and 22F of the holding members 21 and 22 and the device main body 1A, but this is not limiting.

[0037] 6, the holding members 21, 22 may be moved to a second position that does not overlap with the attachment / detachment trajectory of the fixing device 11 by releasing the connection between the other ends 21S, 22S of the holding members 21, 22 and the rear door 20. For example, the rear door 20 may be provided with claws 20a, 20b, and the other ends 21S, 22S of the holding members 21, 22 may be provided with holes that can engage with the claws 20a, 20b. In this case, the holding members 21, 22 and the rear door 20 are connected by the engagement of the claws 20a, 20b with the holes, and the holding members 21, 22 are released from the connection between the rear door 20 by separating the claws 20a, 20b from the holes.

[0038] As in the first embodiment, one ends 21F, 22F of the holding members 21, 22 may be configured to be connectable and disconnectable to the apparatus main body 1A, and the other ends 21S, 22S may be configured to be connectable and disconnectable to the rear door 20. Then, an operator may disconnect at least one of one end 21F and the other end 21S of the holding member 21 and disconnect at least one of one end 22F and the other end 22S of the holding member 22, thereby enabling attachment and detachment of the fixing device 11.

[0039] FIG. 7 is a perspective view showing a printer 1M2 according to a second modification of the first embodiment. The printer 1M2 shown in FIG. 7 has a smaller opening angle than the rear door 20 of the printer 1 according to the first embodiment. This is intended to reduce noise and impact when the rear door 20 is opened, for example. In this case, when the rear door 20 is in the open position, not only the holding members 21 and 22 but also the guide member 125 fixed to the rear door 20 and the rear surface 20r of the rear door 20 (see FIG. 1) overlap the attachment / detachment path of the fixing device 11. Even in this case, the fixing device 11 can be attached to or detached from the device main body 1A by releasing the connection between the holding members 21 and 22 and either the device main body 1A or the rear door 20.

[0040] FIG. 8 is a rear view of a printer 1M3 according to a third variation of the first embodiment. In the first embodiment, both of the holding members 21 and 22 located in the first position are positioned so as to overlap the attachment / detachment trajectory of the fixing device 11, but this is not limiting. For example, as shown in FIG. 8, the holding member 21 may be positioned so as not to overlap the attachment / detachment trajectory of the fixing device 11 while connected to both the housing 23 of the device main body 1A and the rear door 20. Meanwhile, the holding member 22, like in the first embodiment, is positioned so as to overlap the attachment / detachment trajectory of the fixing device 11 while connected to both the housing 24 of the device main body 1A and the rear door 20.

[0041] In this case, the fixing device 11 can be attached to and detached from the apparatus main body 1A by releasing the connection between one end 22F and the other end 22S of the holding member 22 without operating the holding member 21.

[0042] 9 is a rear view of a printer 1M4 according to a fourth variation of the first embodiment. In the first embodiment, the rear door 20 is held in the open position by a pair of holding members 21 and 22, but this is not limiting. In particular, if the rear door 20 is small and lightweight, the rear door 20 in the open position may be held by a single holding member (e.g., holding member 22). In this case, the fixing device 11 can be attached to or detached from the apparatus main body 1A by releasing the connection between one end 22F and the other end 22S of the holding member 22.

[0043] FIG. 10(a) is a perspective view of a printer 1M5 according to Variation 5 of the first embodiment, and FIG. 10(b) is a rear view of the printer 1M5. While the printer 1 according to the first embodiment was a monochrome laser beam printer, the present invention is not limited to this. For example, as in Variation 5, the present invention may be applied to an electrophotographic laser beam printer that forms full-color toner images. In this variation, the detachable unit (replaceable unit) that is detachable from the apparatus main body 1A is, for example, a transfer unit 27. The transfer unit 27 has a transfer belt 27a that carries a toner image transferred from a photosensitive drum to a sheet. Like the fixing device 11 described above, the transfer unit 27 is detachable from the apparatus main body 1A in an attachment / detachment direction AD that is substantially parallel to the horizontal direction.

[0044] 10(a) and 10(b), the holding members 21 and 22 located in the first position overlap the attachment / detachment trajectory of the transfer unit 27 at the dashed line portions J and K. At this time, attachment / detachment of the transfer unit 27 is restricted by the holding members 21 and 22. When attaching or detaching the transfer unit 27 to or from the device main body 1A, the operator releases the connection between one end 21F or the other end 21S of the holding member 21, and also releases the connection between one end 22F or the other end 22S of the holding member 22. This allows the transfer unit 27 to be attached or detached to or from the device main body 1A.

[0045] FIG. 11(a) is a perspective view of a printer 1M6 according to Variation 6 of the first embodiment, and FIG. 11(b) is a rear view of the printer 1M6. Like Variation 5, the printer 1M6 is an electrophotographic laser beam printer that forms full-color toner images. In this variation, the removable units (replacement units) that are detachably attached to the apparatus main body 1A are, for example, process cartridges 28, 29, 30, and 31. Each of the process cartridges 28, 29, 30, and 31 includes a photosensitive drum that carries an electrostatic latent image, a developing roller that develops the electrostatic latent image into a toner image, and a toner storage compartment that stores toner. Like the fixing device 11 described above, the process cartridges 28, 29, 30, and 31 are detachably attached to the apparatus main body 1A in the attachment / detachment direction AD, which is substantially parallel to the horizontal direction.

[0046] 11(a) and 11(b), the holding member 21 in the first position overlaps the attachment / detachment trajectory of the process cartridge 28 at the dashed line portion L. At this time, attachment / detachment of the process cartridge 28 is restricted by the holding member 21. When attaching or detaching the process cartridge 28 to or from the apparatus main body 1A, the operator releases the connection between one end 21F or the other end 21S of the holding member 21. This allows the process cartridge 28 to be attached to or detached from the apparatus main body 1A.

[0047] <Second embodiment> Next, a second embodiment of the present invention will be described. In the second embodiment, a guide member 25 fixed to the rear door 20, rather than the holding members (21, 22), is arranged so as to overlap with the attachment / detachment trajectory of the fixing device 11. For this reason, the same components as those in the first embodiment will not be shown in the drawings or will be described with the same reference numerals in the drawings.

[0048] 12, printer 101 of this embodiment has a device main body 1A and rear door 20 similar to those of the first embodiment, holding members 121 and 122, and guide member 25. Guide member 25, which serves as a connecting member, is connected to rear door 20 so as to move in conjunction with rear door 20.

[0049] [Rear door peripheral configuration] The peripheral configuration of the rear door 20 will be described using Figures 12 and 13. Figure 12 is a perspective view showing the printer 101 with the rear door 20 open. Figure 13 is a rear view showing the interior of the printer 101 with the rear door 20 open. In Figure 13, the outer frame of the fixing device 11 is conveniently indicated by a thick line so that the area occupied by the fixing device 11 can be easily seen.

[0050] 12, the apparatus main body 1A and the rear door 20 are connected by a pair of holding members 121 and 122, which hold the rear door 20 in the open position. As shown in Fig. 13, the holding members 121 and 122 in this embodiment are arranged outside the attachment / detachment locus of the fixing device 11 in the width direction W. In other words, the holding members 121 and 122 are arranged so as not to overlap with the attachment / detachment locus of the fixing device 11.

[0051] 12 and 13, the rear door 20 has a rear surface 20r that faces the apparatus main body 1A when the rear door 20 is in the closed position, and a guide member 25 is connected to the rear surface 20r. The guide member 25 has a plurality of transport ribs 25b extending along the sheet transport direction, and these transport ribs 25b form the double-sided transport path 16 (see FIG. 1) when the rear door 20 is in the closed position. That is, the guide member 25 guides the sheet S passing through the double-sided transport path 16 when the rear door 20 is in the closed position. The downstream ends of the transport ribs 25b in the sheet transport direction form rib tips 25a that protrude upward when the rear door 20 is in the open position.

[0052] The fixing device 11 is configured to be attached to and detached from the apparatus main body 1A through the opening 80, and as shown in Fig. 13, its lower end (broken line portion M) overlaps with the rib tip 25a of the conveying rib 25b of the guide member 25 in the gravity direction G. That is, as shown in Fig. 13, at least a part of the guide member 25 overlaps with the attachment / detachment trajectory of the fixing device 11 when viewed in the attachment / detachment direction AD of the fixing device 11. The attachment / detachment trajectory of the fixing device 11 is the area within the thick line in Fig. 13 extended in the direction of the paper.

[0053] In this state, when the fixing device 11 is attached to or detached from the apparatus main body 1A, it interferes with the guide member 25. In other words, the guide member 25 functions as a restricting member that restricts replacement of the fixing device 11. On the other hand, by arranging the guide member 25 so that it overlaps with the attachment / detachment trajectory of the fixing device 11 in this way, the printer 1 can be made smaller in size in the direction of gravity G.

[0054] [How to install and remove the fixing unit] Next, a method for attaching and detaching the fixing device 11 will be described with reference to FIGS. 14 to 18. FIG. 14 is a plan view showing the guide member 25 and the rear door 20. FIG. 15(a) is an enlarged perspective view showing the dashed line portion N in FIG. 14, and FIG. 15(b) is a cross-sectional view of the dashed line portion N in FIG. 14. FIG. 16 is an enlarged perspective view of the dashed line portion P in FIG. 14. FIG. 17(a) is a cross-sectional view showing the tab 25c of the guide member 25 engaging with the boss 20j of the rear door 20, and FIG. 17(b) is a cross-sectional view showing the tab 25c of the guide member 25 separating from the boss 20j of the rear door 20. FIG. 18 is a perspective view showing the guide member 25 removed from the rear door 20.

[0055] 14, the guide member 25 engages with hook portions 20c, 20d, 20e, 20f, 20g, and 20h provided on the rear surface 20r of the rear door 20. The engagement configurations between these hook portions 20c, 20d, 20e, 20f, 20g, and 20h and the guide member 25 are similar, so only the engagement configuration between the hook portion 20g and the guide member 25 will be described using FIGS. 15(a) and 15(b).

[0056] 15(a) and 15(b), a hook portion 20g protrudes from the rear surface 20r of the rear door 20, and the hook portion 20g has an engaging portion 20g1 extending along the rear surface 20r. The guide member 25 has an engaged portion 25f that is inserted between the engaging portion 20g1 of the hook portion 20g and the rear surface 20r and engages with the engaging portion 20g1.

[0057] 14, the rear door 20 has a boss 20j located between the hook portions 20c and 20d. The boss 20j protrudes upward from the rear surface 20r when the rear door 20 is in the open position. The guide member 25 has a tab 25c located at a position corresponding to the boss 20j.

[0058] 16, the tab 25c has a mating hole 25d, and the boss 20j of the rear door 20 is fitted into the mating hole 25d. As a result, the guide member 25 is positioned relative to the rear door 20 in the direction of arrow Q.

[0059] As shown in Fig. 17(a), an operator can deform tab 25c in the direction of arrow R by hooking a finger on tip 25e of tab 25c and pulling tip 25e toward the operator. When tab 25c is deformed in the direction of arrow R, engagement between mating hole 25d and boss 20j is released, as shown in Fig. 17(b). In other words, tab 25c and boss 20j form a so-called snap fit that can be connected and disconnected without the need for tools.

[0060] Thereafter, the worker moves the guide member 25 in the direction of arrow T to remove the guide member 25 from the hook portions 20c, 20d, 20e, 20f, 20g, and 20h of the rear door 20. This releases the connection between the guide member 25 and the rear door 20.

[0061] By performing the above operations, guide member 25 becomes movable, and can be moved to a position that does not overlap the attachment / detachment trajectory of fixing device 11. That is, guide member 25 is configured to be movable, with rear door 20 in the open position, from a first position (position shown in FIGS. 12 and 13) that overlaps the attachment / detachment trajectory of fixing device 11, to a second position that does not overlap the attachment / detachment trajectory of fixing device 11. In the second position, guide member 25 allows attachment / detachment of fixing device 11 to / from apparatus main body 1A. Note that the second position may be any position that does not overlap the attachment / detachment trajectory of fixing device 11. For example, the position of guide member 25 when it is removed from rear door 20 and placed away from printer 101 can be considered the second position.

[0062] The method for removing the fixing device 11 from the apparatus main body 1A is the same as in the first embodiment, and therefore the explanation will be omitted. The work for attaching the fixing device 11 to the apparatus main body 1A can be performed by performing the reverse of the work for removing the fixing device 11 described above.

[0063] As described above, the guide member 25 of this embodiment is configured to be movable from a first position (the position shown in FIGS. 12 and 13) to a second position (for example, a position removed from the rear door 20) that does not overlap the attachment / detachment path of the fixing device 11. Because the guide member 25 overlaps the attachment / detachment path of the fixing device 11 in the first position, the printer 1 can be made smaller in size in the direction of gravity G. Furthermore, the guide member 25 can be moved to the second position by releasing its connection with the rear door 20, and in this state the fixing device 11 can be attached to or detached from the apparatus main body 1A. This ensures good operability when attaching or detaching the fixing device 11.

[0064] Furthermore, the guide member 25 can be easily disconnected from the rear door 20 by simply releasing the engagement between the boss 20j and the tab 25c that form the snap fit and moving the guide member 25 away from the hook portions 20c to 20h. This improves the workability when attaching and detaching the fixing device 11.

[0065] <Other embodiments> In the above-described embodiment, the detachable unit attached to and detached from the apparatus main body 1A is exemplified by the fixing device 11, the transfer unit 27, or the process cartridge 28, but is not limited to these. For example, a toner cartridge that stores toner, a cartridge tray that supports a process cartridge, or the like may be used as the detachable unit.

[0066] In addition, in all of the above-described embodiments, the configuration has been described in which the rear door 20 is opened to attach and detach the detachable unit such as the fixing device 11, but the present invention is not limited to this. For example, instead of the rear door 20, a top cover provided on the top surface of the printer 1 may be opened to attach and detach the detachable unit such as the fixing device 11.

[0067] Furthermore, in the first embodiment, the claw portion 23a is provided on the housing 23 of the device body 1A, and the hole portion 21a is provided on one end 21F of the holding member 21, but this is not limiting. For example, the hole portion 21a may be provided on the housing 23 of the device body 1A, and the claw portion 23a may be provided on one end 21F of the holding member 21. That is, it is sufficient that the claw portion 23a is provided on either the device body 1A or the end 21F of the holding member 21, and the hole portion 21a is provided on the other of the device body 1A or the end 21F of the holding member 21.

[0068] Similarly, in the first modification of the first embodiment, the claw portion 20a is provided on the rear door 20 and the hole portion is provided on the other end 21S of the holding member 21, but this is not limiting. For example, the hole portion may be provided on the rear door 20 and the claw portion 20a may be provided on the other end 21S of the holding member 21. That is, it is sufficient that the claw portion 20a is provided on either the rear door 20 or the other end 21S of the holding member 21, and the hole portion is provided on the other of the rear door 20 or the other end 21S of the holding member 21.

[0069] In addition, in all of the above-described embodiments, the holding members 21 and 22 and the guide member 25 are configured to be movable from the first position to the second position by releasing the connection between at least one of the apparatus main body 1A and the rear door 20. However, this is not limiting. That is, the holding members 21 and 22 and the guide member 25 may be configured to be movable from the first position to the second position without releasing the connection between the apparatus main body 1A and the rear door 20. For example, the flexible holding members 21 and 22 may be configured longer than in the first embodiment, and the rear door 20 may be slightly lifted from the open position to bend the holding members 21 and 22 outward in the width direction W, thereby retracting the holding members 21 and 22 from the attachment / detachment trajectory of the fixing device 11. Furthermore, for example, the guide member 25 may be supported by the rear door 20 so as to be movable from a position overlapping the attachment / detachment trajectory of the fixing device 11 to a position not overlapping the attachment / detachment trajectory.

[0070] Furthermore, although the above-described embodiments have been described using an electrophotographic printer, the present invention is not limited to this. For example, the present invention can also be applied to an inkjet image forming apparatus that forms an image on a sheet by ejecting ink liquid from nozzles.

[0071] Summary of the Disclosure The present disclosure includes at least the following: (Configuration 1) An image forming apparatus for forming an image on a sheet, a device body having an opening; a detachable unit that is attached to and detached from the device body through the opening; a door that is supported on the device body so as to be openable and closable, and that is movable between a closed position that closes the opening and an open position that opens the opening; a connecting member connected to the door so as to interlock with the door, the connecting member is movable from a first position overlapping with the attachment / detachment trajectory of the detachable unit to a second position not overlapping with the attachment / detachment trajectory of the detachable unit and allowing the detachable unit to be attached to or detached from the apparatus main body when the door is in the open position; An image forming apparatus characterized by: (Configuration 2) the connecting member has one end connected to the device body and the other end connected to the door, and is a holding member that holds the door in the open position. 2. The image forming apparatus according to claim 1, (Configuration 3) the holding member is movable from the first position to the second position by releasing the connection between the one end and the device body. 3. The image forming apparatus according to claim 2, wherein: (Configuration 4) Either the device body or the one end portion has a claw portion, the other of the device body and the one end portion has a hole portion that can be engaged with the claw portion, The holding member and the device main body are connected by the engagement of the claw portion and the hole portion, and the holding member and the device main body are released from connection by the separation of the claw portion and the hole portion. 4. The image forming apparatus according to configuration 3. (Configuration 5) The holding member is movable from the first position to the second position by releasing the connection between the other end and the door. 3. The image forming apparatus according to claim 2, wherein: (Configuration 6) One of the door and the other end portion has a claw portion, The other of the door and the other end portion has a hole portion that can be engaged with the claw portion, The claw portion engages with the hole portion to connect the holding member to the door, and the claw portion separates from the hole portion to release the connection between the holding member and the door. 6. The image forming apparatus according to configuration 5. (Configuration 7) The retaining member is flexible and curved when the door is in the closed position. 7. The image forming apparatus according to any one of configurations 2 to 6. (Configuration 8) the door has a surface that faces the device body when the door is in the closed position; the connecting member is a guide member that is connected to the surface of the door and guides the seat when the door is positioned at the closed position; 2. The image forming apparatus according to claim 1, (Configuration 9) The guide member is movable from the first position to the second position by being disconnected from the surface of the door. 9. The image forming apparatus according to configuration 8, (Configuration 10) the door constitutes a part of the exterior of the image forming apparatus; 10. The image forming apparatus according to any one of configurations 1 to 9. (Configuration 11) the detachable unit is a fixing unit that fixes a toner image formed on a sheet to the sheet; 11. The image forming apparatus according to any one of configurations 1 to 10. (Configuration 12) the detachable unit is a transfer unit having a transfer belt that carries a toner image transferred from the photosensitive drum and to be transferred onto a sheet; 11. The image forming apparatus according to any one of configurations 1 to 10. (Configuration 13) the removable unit is a process cartridge having a photosensitive drum that carries an electrostatic latent image, a developing roller that develops the electrostatic latent image into a toner image, and a toner containing section that contains toner; 11. The image forming apparatus according to any one of configurations 1 to 10. [Explanation of symbols]

[0072] 1, 1M1, 1M2, 1M3, 1M4, 1M5, 1M6, 101: image forming apparatus (printer) / 1A: apparatus body / 11: detachable unit, fixing unit (fixing device) / 20: door (rear door) / 20r: surface (rear) / 21, 22: connecting member (holding member) / 21a: hole / 21F: one end / 21S: other end / 23a: claw portion / 25: connecting member (guide member) / 27: detachable unit (transfer unit) / 28: detachable unit (process cartridge) / 80: opening / S: sheet

Claims

1. An image forming apparatus for forming an image on a sheet, a device body having an opening; a detachable unit that is attached to and detached from the device body through the opening; a door that is supported on the device body so as to be openable and closable, and that is movable between a closed position that closes the opening and an open position that opens the opening; a connecting member connected to the door so as to interlock with the door, the connecting member is movable from a first position overlapping with a detachment track of the detachable unit to a second position not overlapping with the detachment track of the detachable unit and allowing the detachable unit to be attached to or detached from the apparatus main body when the door is in the open position; An image forming apparatus characterized by:

2. the connecting member has one end connected to the device body and the other end connected to the door, and is a holding member that holds the door in the open position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. the holding member is movable from the first position to the second position by releasing the connection between the one end and the device body.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a recording medium.

4. Either the device body or the one end portion has a claw portion, the other of the device body and the one end portion has a hole portion that can be engaged with the claw portion, The holding member and the device main body are connected by the engagement of the claw portion and the hole portion, and the holding member and the device main body are released from connection by the separation of the claw portion and the hole portion.

4. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium.

5. The holding member is movable from the first position to the second position by releasing the connection between the other end and the door.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a recording medium.

6. One of the door and the other end portion has a claw portion, The other of the door and the other end portion has a hole portion that can be engaged with the claw portion, The claw portion engages with the hole portion to connect the holding member to the door, and the claw portion separates from the hole portion to release the connection between the holding member and the door.

6. The image forming apparatus according to claim 5,

7. The retaining member is flexible and curved when the door is in the closed position.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus is a recording medium.

8. the door has a surface that faces the device body when the door is in the closed position; the connecting member is a guide member that is connected to the surface of the door and guides the seat when the door is positioned at the closed position; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. The guide member is movable from the first position to the second position by being disconnected from the surface of the door.

9. The image forming apparatus according to claim 8,

10. the door constitutes a part of the exterior of the image forming apparatus; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

11. the detachable unit is a fixing unit that fixes a toner image formed on a sheet to the sheet; 11. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

12. the detachable unit is a transfer unit having a transfer belt that carries a toner image transferred from the photosensitive drum and to be transferred onto a sheet; 11. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

13. the removable unit is a process cartridge having a photosensitive drum that carries an electrostatic latent image, a developing roller that develops the electrostatic latent image into a toner image, and a toner containing section that contains toner; 11. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images