Image forming apparatus

Abstract

To improve workability of attaching / detaching work, compared with the case of including all same attaching / detaching structures, in a constitution having a first attaching / detaching unit opposed to belt-like means in a region where an outer surface of the belt-like means faces upward and a second attaching / detaching unit opposed to the belt-like means in a region where the outer surface of the belt-like means faces downward.SOLUTION: An image forming apparatus (U) includes: first detachable units (Py and Pm) arranged opposite to a region (B1) where an outer surface of belt-like means (B) faces upward; and second detachable units (Pc and Pk) arranged opposite to a region (B2) where the outer surface of the belt-like means (B) faces downward, where the first detachable units (Py and Pm) are detachable laterally in a state in which first storage means (SR1) is pulled out, and where the second detachable units (Pc and Pk) are detachable upward in a state in which second storage means (SR2) is pulled out.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] Regarding the attachment / detachment structure of attachment / detachment means such as replacement parts in an image forming apparatus, the technique described in Patent Document 1 below has been conventionally known.

[0003] Patent Document 1 describes a configuration in which a developing unit (Gg to Gk) is detachable outward in the horizontal direction with a marking module (1) pulled forward, and a photoreceptor unit (Ug to Uk) is detached on the side opposite to the developing unit (Gg to Gk) in the horizontal direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a configuration having a first attachment / detachment unit facing the belt-like means in a region where the outer surface of the belt-like means faces upward, and a second attachment / detachment unit facing the belt-like means in a region where the outer surface of the belt-like means faces downward, the technical problem is to improve the workability of the attachment / detachment operation as compared with the case of having the same attachment / detachment structure for all.

Means for Solving the Problems

[0006] To solve the above technical problem, the image forming apparatus according to the invention described in claim 1 is a belt-like means, and a first attachment / detachment unit disposed to face the belt-like means in a region where the outer surface of the belt-like means faces upward, and A first accommodating means for accommodating the first detachable unit and being insertable into and removable from the apparatus, A second detachable unit disposed to face the belt-like means in a region where the outer surface of the belt-like means faces downward, A second accommodating means for accommodating the second detachable unit and being insertable into and removable from the apparatus, A third detachable unit that is disposed opposite to the first detachable unit and is detachably attachable in a lateral direction with respect to the first accommodating means, A fourth detachable unit that is disposed opposite to the second detachable unit and is detachably attachable in a lateral direction with respect to the second accommodating means, The first and second detachable units having image holding means, The third and fourth detachable units having developing means, Comprising, The first detachable unit is detachable in a lateral direction with respect to the first accommodating means in a state where the first accommodating means is taken out, The The second detachable unit is detachable upward with respect to the second accommodating means in a state where the second accommodating means is taken out. The second detachable unit is Characterized in that it is detachable upward with respect to the second accommodating means in a state where the second accommodating means is taken out.

[0008] Claim 2 The invention according to Claim 1 In the image forming apparatus according to A third detachable unit heavier than the first detachable unit, A fourth detachable unit heavier than the second detachable unit, Characterized by comprising.

[0009] Claim 3 The invention according to Claim 2 In the image forming apparatus according to A first moving means attached to the third detachable unit when the third detachable unit is detached and moving the third detachable unit in a lateral direction, A second moving means attached to the fourth detachable unit when the fourth detachable unit is detached and moving the fourth detachable unit in a lateral direction, Characterized by comprising.

[0011] Claim 4 The invention according to claim 1 to 3In the image forming apparatus according to any one of the following, the first detachable unit and the second detachable unit having image holding means, a fifth detachable unit having first cleaning means for cleaning the image holding means of the first detachable unit and being detachable from the first housing means, a sixth detachable unit having second cleaning means for cleaning the image holding means of the second detachable unit and being detachable from the second housing means, first holding means for changing the posture of the first cleaning means in a direction in which the opening on the image holding means side of the first cleaning means faces upward when the fifth detachable unit is removed, and holding the first cleaning means in the posture with the opening facing upward, second holding means for changing the posture of the second cleaning means in a direction in which the opening on the image holding means side of the second cleaning means faces upward when the sixth detachable unit is detached or attached, and holding the second cleaning means in the posture with the opening facing upward, characterized by comprising.

[0012] Claim 5 The invention described in Claim 4 In the image forming apparatus described in the fifth detachable unit that is detachably attached to the first housing means in a lateral direction, the sixth detachable unit that is detachably attached to the second housing means in a lateral direction, characterized by comprising.

[0013] Claim 6 The invention described in Claim 4 or 5 In the image forming apparatus described in the first detachable unit that is detached or attached through a path through which the fifth detachable unit is detached or attached, characterized by comprising.

Advantages of the Invention

[0014] According to the invention described in claim 1, in a configuration having a first detachable unit facing the belt-like means in a region where the outer surface of the belt-like means faces upward, and a second detachable unit facing the belt-like means in a region where the outer surface of the belt-like means faces downward, the workability of the attaching / detaching operation can be improved as compared with the case of providing all the same attaching / detaching structures. Also, Claim 1 According to the invention described in, the third detachable unit and the fourth detachable unit can be attached / detached in the horizontal direction. Furthermore, according to the invention described in Claim 1, the workability of the replacement operation of the image holding means and the developing means can be improved. Claim 2 According to the invention described in, the burden of the work can be reduced as compared with the case of lifting the heavy third detachable unit and the fourth detachable unit upward. Claim 3 According to the invention described in, the third detachable unit and the fourth detachable unit can be attached / detached safely and the workability is improved as compared with the case of not using the first moving means and the second moving means.

[0015] Claim 4 According to the invention described in, scattering and leakage of the developer can be suppressed as compared with the case where the opening does not face upward when the first cleaning means and the second cleaning means are attached / detached. Claim 5 According to the invention described in, the fifth detachable unit and the sixth detachable unit can be attached / detached in the horizontal direction. Claim 6 According to the invention described in, when the path through which the fifth detachable unit is attached / detached is not passed through by the first detachable unit, there is no need to secure a path dedicated to the first detachable unit, and the space can be effectively utilized as a whole.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

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Figure 5

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Figure 8

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Figure 10

Figure 11

Figure 12

Figure 13

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Next, examples as specific examples of embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples. For the sake of easy understanding of the following description, in the drawings, the front-rear direction (the width direction of the medium) is the X-axis direction, the left-right direction (the conveyance direction of the medium) is the Y-axis direction, and the up-down direction is the Z-axis direction. The directions or sides indicated by the arrows X, -X, Y, -Y, Z, -Z are the front, rear, right, left, upper, lower, or front side, rear side, right side, left side, upper side, and lower side, respectively. In the drawings, those with "·" in "○" mean arrows from the back to the front of the paper surface, and those with "×" in "○" mean arrows from the front to the back of the paper surface. In the following description using the drawings, illustrations other than the members necessary for the description are appropriately omitted for easy understanding.

EXAMPLE

[0018] FIG. 1 is an explanatory view of the image forming apparatus of Example 1 of the present invention. In FIG. 1, as an example of the image forming apparatus of the present invention, a printer U has toner image forming apparatuses UY, UM, UC, UK as examples of image forming means. The toner image forming apparatus UY for Y (yellow) forms a Y-color image in response to a Y (yellow) color image signal. Similarly, the toner image forming apparatuses UM, UC, UK form images of respective colors in response to image signals of respective colors of M (magenta), C (cyan), and K (black). The toner image forming devices UY to UK and the power supply circuit are controlled for the writing timing and the power supply timing in accordance with a control signal from a control unit as an example of control means. When print information is input from a personal computer (not shown) as an example of an information processing device connected to the printer U in the control unit of the first embodiment, the print information is converted into image signals of Y, M, C, and K, and a control signal is output to the toner image forming devices UY to UK.

[0019] The Y-color toner image forming device UY includes a photosensitive drum Py as an example of image holding means, a charger CRy as an example of charging means, a writing device LPHy as an example of latent image forming means, a developing device Gy as an example of developing means, and a drum cleaner CLy as an example of cleaning means. The charger CRy charges the surface of the photosensitive drum Py. The writing device LPHy forms a Y-color electrostatic latent image on the surface of the photosensitive drum Py based on the print information. The developing device Gy develops the latent image on the photosensitive drum Py into a Y-color image. The image held on the photosensitive drum Py is transferred to the intermediate transfer belt B by a primary transferrer T1y as an example of primary transfer means disposed to face the photosensitive drum Py. The drum cleaner CLy removes and cleans the deposits on the surface of the photosensitive drum Py after primary transfer. The M-color, C-color, and K-color toner image forming devices UM, UC, and UK also have photosensitive drums Pm to Pk, chargers CRm to CRk, etc. in the same manner as the Y-color toner image forming device UY.

[0020] In the first embodiment, an intermediate transfer belt B as an example of belt means is disposed below the Y-color and M-color toner image forming devices UY and UM so as to face below the photosensitive drums Py and Pm. In the first embodiment, in the range of a region B1 where the outer surface (surface) of the intermediate transfer belt B faces upward, the Y-color and M-color photosensitive drums Py and Pm are disposed to face each other, and in the range of a region B2 where the surface of the intermediate transfer belt B faces downward, the C-color and K-color photosensitive drums Pc and Pk are disposed to face each other.

[0021] The intermediate transfer belt B is supported by a plurality of support means including a drive roll Rd as an example of drive means, a backup roll T2a as an example of opposing means, and a driven roll Rf as an example of driven means. Drive is transmitted to the drive roll Rd from a motor as an example of a drive source (not shown). The intermediate transfer belt B is rotated in the direction of the rotation direction Ya as the drive roll Rd rotates. Along the rotation direction Ya of the intermediate transfer belt B, a belt cleaner CLb as an example of cleaning means is disposed on the downstream side of the secondary transfer area Q4. The belt cleaner CLb removes the residue adhering to the surface of the intermediate transfer belt B after passing through the secondary transfer area Q4.

[0022] A paper feed tray TR1 as an example of housing means is disposed below the printer U. The paper feed tray TR1 houses a sheet S as an example of a medium. The sheet S in the paper feed tray TR1 is fed by a paper feed roller Rp as an example of paper feed means and conveyed toward the secondary transfer area Q4 by a conveyance roll Ra as an example of conveyance means. A secondary transfer roll T2b as an example of transfer means is disposed at a position facing the backup roll T2a with the intermediate transfer belt B interposed therebetween. A secondary transfer voltage is applied from a power circuit between the secondary transfer roll T2b and the backup roll T2a. A transfer conveyance belt BTB as an example of conveyance means is stretched around the secondary transfer roll T2b. The sheet S conveyed to the secondary transfer area Q4 by the conveyance roll Ra has an image transferred from the intermediate transfer belt B when passing through the secondary transfer area Q4 and is conveyed by the transfer conveyance belt BTB. The backup roll T2a and the secondary transfer roll T2b constitute a secondary transfer device T2 as an example of the transfer means of the first embodiment.

[0023] The sheet S conveyed by the transfer conveyance belt BTB is sent to a fixing device F as an example of fixing means. The fixing device F fixes the unfixed toner on the surface of the sheet S. The sheet S that has passed through the fixing device F is discharged and stacked on a discharge tray TRh as an example of a stacking means.

[0024] (Description of the toner image forming devices for Y color and M color) FIG. 2 is an enlarged view of the Y-color toner image forming device of Example 1. FIG. 3 is a perspective view of the Y-color toner image forming device of Example 1. Next, the toner image forming devices UY and UM for Y color and M color will be described. Since the M-color toner image forming device UM has the same configuration as the Y-color toner image forming device UY, the Y-color toner image forming device UY will be described, and the detailed description of the M-color toner image forming device UM will be omitted. In FIGS. 2 and 3, the Y-color toner image forming device UM has, as an example of a frame body, a front plate 1 on the front side and a rear plate 2 on the rear side. The photosensitive drum Py, the charger CRy, the writing device LPHy, the developing device Gy, and the drum cleaner CLy are arranged between the front plate 1 and the rear plate 2. Therefore, both front and rear ends of the photosensitive drum Py as an example of the first detachable unit, the charger CRy, the writing device LPHy, the developing device Gy (developing unit) as an example of the third detachable unit, and the drum cleaner CLy (cleaner unit) as an example of the first cleaning means and also as an example of the fifth detachable unit are supported by the front plate 1 and the rear plate 2.

[0025] A pair of left and right frames 5 as an example of strength means are supported above the front plate 1 and the rear plate 2. A pair of left and right slide rails SR1 extending in the front-rear direction are supported on the frame 5 as an example of the first housing means. The slide rail SR1 supports the toner image forming device UY so as to be movable (pullable out and storable) in the front-rear direction with respect to the main body of the printer U, that is, along the axial direction of the photosensitive drum Py. That is, the slide rail SR1 has a function of housing the toner image forming device UY inside the printer U or pulling it out to the outside. The attachment and detachment of the photosensitive drum Py, the drum cleaner CLy, and the developing device Gy described later are performed in a state where the toner image forming device UY is pulled out forward from the main body of the printer U.

[0026] FIG. 4 is an enlarged view of the main part of the rear end of the Y-color toner image forming apparatus of Example 1. FIG. 4A is an explanatory view of the state where the drum cleaner is fixed, FIG. 4B is an explanatory view of the state where the screwing of the drum cleaner is released from the state of FIG. 4A, and FIG. 4C is an enlarged view of the main part of the support portion of the rotating shaft of the drum cleaner. FIG. 5 is a cross-sectional view of the main part of the Y-color toner image forming apparatus of Example 1. FIG. 5A is an explanatory view of the state corresponding to FIG. 4A, and FIG. 5B is an explanatory view of the state corresponding to FIG. 4B. In FIGS. 4 and 5, a drum receiving portion 3, which is an example of a support means for the first detachable unit, is supported on the front surface of the rear plate 2. Although not shown, a similar drum receiving portion is also arranged on the rear surface of the front plate 1. The drum receiving portion 3 is formed in a horizontal U-shape with the right side (the drum cleaner CLy side) open. The drum receiving portion 3 houses a bearing portion 4, which is an example of bearing means. The bearing portion 4 rotatably supports the rotating shaft 6 of the photosensitive drum Py. An upper fixing plate 4a extending upward and a lower fixing plate 4b extending downward are formed on the right portion of the bearing portion 4. Screw holes 4c are formed in the respective fixing plates 4a and 4b, and the drum receiving portion 3 is configured to be fastened with screws (not shown). Therefore, when the screws are tightened, the photosensitive drum Py is fixed to the front plate 1 and the rear plate 2, and when the screws are removed, the photosensitive drum Py can be removed from the front plate 1 and the rear plate 2.

[0027] A cleaner fixing portion 4d, which is an example of a fixing portion of the fifth detachable unit, is formed on the bearing portion 4 to the right of the upper fixing plate 4a. The cleaner fixing portion 4d is provided with a stopper 4e, which is an example of holding means and an example of rotation restricting means. In FIGS. 4A and 4B, the stopper 4e is formed in a shape in which the right end of a plate-like member extending to the right (the drum cleaner CLy side) is bent. The holding means may have another configuration as long as it holds the cleaning means in a posture with the opening facing upward. Further, below the cleaner fixing portion 4d and on the side of the rotation shaft 6, a cleaner bearing 4f is formed as an example of the rotation support portion of the fifth detachable unit. In FIG. 4C, the cleaner bearing 4f of the first embodiment is composed of a U-shaped groove with an open upper part.

[0028] A fixing plate 11 is supported at the front end of the drum cleaner CLy as an example of the fixed portion. Although illustration and description are omitted, a fixing plate that is symmetrical front and back is also provided at the rear end of the drum cleaner CLy. On the upper part of the fixing plate 11, a fixed flange 12 that is bent to face the cleaner fixing portion 4d is formed. A screw hole 12a is formed in the fixed flange 12, and it can be fastened to the cleaner fixing portion 4d with a screw (not shown) passing through the screw hole 12a. Below the fixing plate 11, a rotation shaft 13 is supported corresponding to the cleaner bearing 4f. The rotation shaft 13 is formed in a protruding shape that projects rearward from the fixing plate 11. The rotation shaft 13 is rotatably supported in a state of being fitted into the cleaner bearing 4f, and when it moves forward in the axial direction, the rotation shaft 13 can be detached from the cleaner bearing 4f. Therefore, the drum cleaner CLy of the first embodiment is configured to be removable when rotated so that the opening on the side of the photosensitive drum Py faces upward.

[0029] Therefore, in the first embodiment, when the rotation shaft 13 is fitted into the cleaner bearing 4f and the fixed flange 12 is screwed to the cleaner fixing portion 4d, the drum cleaner CLy is fixed to the front plate 1 and the rear plate 2 via the bearing portion 4 of the photosensitive drum Py. When the screw of the fixed flange 12 is removed, the rotation axis 13 is arranged at the lower left (on the side of the photosensitive drum Py and below) with respect to the center of gravity of the drum cleaner CLy. As a result, in the state of the drum cleaner CLy as viewed from the front (the state in FIG. 5), it rotates in the clockwise direction. That is, the fixed flange 12 rotates in a direction away from the cleaner fixing portion 4d. Therefore, it rotates so that the opening on the photosensitive drum Py side of the drum cleaner CLy faces upward. Accordingly, compared with the case where the opening faces sideways or downward when the drum cleaner CLy is attached or detached, scattering and leakage of the developer from the drum cleaner CLy are suppressed.

[0030] In addition, in the first embodiment, when the drum cleaner CLy rotates around the rotation axis 13, as shown in FIG. 4B, when the fixed flange 12 contacts the stopper 4e, the rotation of the drum cleaner CLy is held in a stopped state. That is, the opening of the drum cleaner CLy is held in a state facing upward. If the stopper 4e is not provided, the drum cleaner CLy may rotate too much, and the developer in the drum cleaner CLy may scatter and leak. However, this is suppressed in the first embodiment. In particular, when the drum cleaner CLy has a certain weight, if the rotation of the drum cleaner CLy does not stop, there is a risk of accidents such as injury to the operator. However, in the first embodiment, the rotation of the drum cleaner CLy is stopped by the stopper 4e, and the safety is also improved.

[0031] FIG. 6 is an explanatory view of the Y-color toner image forming apparatus according to the first embodiment. FIG. 6A is an explanatory view of the state where the drum cleaner is removed from the state of FIG. 5B, and FIG. 6B is an explanatory view of the state where the photosensitive drum is removed from the state of FIG. 6A. In FIG. 5, when the drum cleaner CLy is lifted while it is rotating, the rotating shaft 13 disengages from the cleaner bearing 4f and the fixed flange 12 disengages from the stopper 4e. Then, when the drum cleaner CLy is moved rightward, that is, in the lateral direction (in the embodiment, horizontally as an example), the drum cleaner CLy can be detached from the front plate 1 and the rear plate 2. In the present specification and the embodiments, the "lateral direction" is used to mean an angular range within 90 degrees, with the horizontal direction being 0 degrees and 45 degrees up and down. When attaching the drum cleaner CLy, the reverse procedure of detachment may be performed. In FIG. 6, when the drum cleaner CLy is removed, by removing the screws of the fixed plates 4a and 4b, the photosensitive drum Py can be moved rightward, that is, in the lateral direction, and removed. Therefore, in the first embodiment, the photosensitive drum Py of color Y is removed using the space through which the drum cleaner CLy passes when it is removed.

[0032] FIG. 7 is an explanatory view of the case where the first moving means is used in the Y-color toner image forming apparatus of the first embodiment. FIG. 7A is an explanatory view of the state where the first moving means is mounted, and FIG. 7B is an explanatory view of the state where the developing means is removed from the state of FIG. 7A. The developing device Gy of the first embodiment is screwed to the front plate 1 and the rear plate 2 with screws (not shown) at the front end and the rear end of the developing container 21. When moving the developing device Gy, in the first embodiment, the upper lifter 22 as an example of the first moving means is used. The upper lifter 22 has a pair of front and rear support portions 23. At the left end of the support portion 23, a handle 24 as an example of an operation portion is supported. In FIG. 7A, when the handle 24 is moved leftward with the lower surfaces of the front end portion and the rear end portion of the developing container 21 supported on the upper surface of the support portion 23, as shown in FIG. 7B, the developing device Gy moves leftward. Thus, the developing device Gy is detached from the front plate 1 and the rear plate 2. When attaching the developing device Gy, it can be done by performing the reverse operation of detachment.

[0033] (Description of C-color and K-color toner image forming devices) FIG. 8 is an enlarged view of the K-color toner image forming device of Example 1. FIG. 9 is a perspective view of the K-color toner image forming device of Example 1. Next, the C-color and K-color toner image forming devices UC and UK will be described. Since the C-color toner image forming device UC has the same configuration as the K-color toner image forming device UK, the K-color toner image forming device UK will be described, and a detailed description of the C-color toner image forming device UC will be omitted. In FIGS. 8 and 9, the K-color toner image forming device UK has, as an example of a frame body, a front front plate 101 and a rear rear plate 102. The photosensitive drum Pk, charger CRk, writing device LPHk, developing device Gk, and drum cleaner CLk are arranged between the front plate 101 and the rear plate 102. Therefore, the photosensitive drum Pk as an example of the second detachable unit, the charger CRk, the writing device LPHk, the developing device Gk (developing unit) as an example of the fourth detachable unit, and the drum cleaner CLk (cleaner unit) as an example of the second cleaning means, which is also an example of the sixth detachable unit, are supported at both front and rear ends by the front plate 101 and the rear plate 102.

[0034] A pair of left and right frames 105, as an example of strength means, are supported at the lower parts of the front plate 101 and the rear plate 102. A pair of left and right slide rails SR2, as an example of the second housing means, which extend in the front-rear direction, are supported on the frame 105. The slide rail SR2 supports the toner image forming device UK so as to be movable (pullable out and storable) in the front-rear direction with respect to the main body of the printer U, that is, along the axial direction of the photosensitive drum Pk. That is, the slide rail SR2 has a function of housing the toner image forming device UK inside the printer U or pulling it out to the outside. The detachment and attachment of the photosensitive drum Pk, drum cleaner CLk, and developing device Gk, which will be described later, are performed in a state where the toner image forming device UK is pulled out forward from the main body of the printer U.

[0035] FIG. 10 is an enlarged view of a main part of the rear end of the K-color toner image forming apparatus according to Example 1. FIG. 10A is an explanatory view of a state in which the drum cleaner is fixed, and FIG. 10B is an explanatory view of a state in which the screwing of the drum cleaner is released from the state of FIG. 10A. FIG. 11 is a cross-sectional view of a main part of the K-color toner image forming apparatus according to Example 1. FIG. 11A is an explanatory view of a state corresponding to FIG. 10A, and FIG. 11B is an explanatory view of a state corresponding to FIG. 10B. In FIGS. 10 and 11, a drum receiving portion 103, which is an example of a support means for the second detachable unit, is supported on the front surface of the rear plate 102. Although not shown, a similar drum receiving portion is also arranged on the rear surface of the front plate 101. The drum receiving portion 103 is formed in a U shape with an open upper portion. A bearing portion 104, which is an example of a bearing means, is accommodated in the drum receiving portion 103. The bearing portion 104 rotatably supports the rotation shaft 106 of the photosensitive drum Pk. A fixing plate 104a extending in the left-right direction is formed at the upper end portion of the bearing portion 104. A screw hole 104c is formed in the fixing plate 104a, and it is configured to be fastened to the drum receiving portion 103 with a screw (not shown). Therefore, in a state where the screw is tightened, the photosensitive drum Pk is fixed to the front plate 101 and the rear plate 102, and when the screw is removed, the photosensitive drum Pk can be removed from the front plate 101 and the rear plate 102.

[0036] A cleaner fixing portion 107, which is an example of a fixing portion of the sixth detachable unit, is formed on the left side surface of the drum receiving portion 103. A stopper 108, which is an example of a holding means and also an example of a rotation restricting means, is arranged to the left of the cleaner fixing portion 107. In FIGS. 10A and 10B, the stopper 108 is supported by the rear plate 102 and is formed in a plate shape bent forward. Also, at the lower left part of the drum receiving part 103, a cleaner bearing 109, which is an example of a rotation support part of a sixth detachable unit, is formed at a position below the cleaner fixing part 107 and on the side of the rotation shaft 106. The cleaner bearing 109 of the first embodiment is composed of a U-shaped groove with an open upper part, similar to the cleaner bearing 4f.

[0037] A fixing plate 111, which is an example of a fixed part, is supported at the rear end of the drum cleaner CLk. Although not shown and described, a fixing plate symmetric in the front and rear is also provided at the front end of the drum cleaner CLk. At the upper part of the fixing plate 111, a fixed flange 112 bent to face the cleaner fixing part 107 is formed. A screw hole 112a is formed in the fixed flange 112, and it can be fastened to the cleaner fixing part 107 with a screw (not shown) passing through the screw hole 112a. At the lower part of the fixing plate 111, a rotation shaft 113 is supported corresponding to the cleaner bearing 109. The rotation shaft 113 is formed in a protruding shape projecting rearward from the fixing plate 111. The rotation shaft 113 is rotatably supported in a state of being fitted into the cleaner bearing 109, and when the drum cleaner CLk is lifted upward, the rotation shaft 113 can be detached from the cleaner bearing 109.

[0038] Therefore, in the first embodiment, when the rotation shaft 113 is fitted into the cleaner bearing 109 and the fixed flange 112 is screwed to the cleaner fixing part 107, the drum cleaner CLk is fixed to the front plate 101 and the rear plate 102 via the bearing part 104 of the photosensitive drum Pk. When the screw of the fixed flange 112 is removed, the rotation axis 113 is arranged at the lower right (on the side of the photoreceptor drum Pk and downward) with respect to the center of gravity of the drum cleaner CLk. As a result, in the state of the drum cleaner CLk as viewed from the front (the states in FIGS. 10 and 11), it rotates counterclockwise. That is, the fixed flange 112 rotates in a direction away from the cleaner fixing portion 107. Therefore, it rotates so that the opening on the photoreceptor drum Pk side of the drum cleaner CLk faces upward. Accordingly, compared with the case where the opening faces sideward or downward when the drum cleaner CLk is attached and detached, scattering and leakage of the developer from the drum cleaner CLk are suppressed.

[0039] In addition, in the first embodiment, when the drum cleaner CLk rotates about the rotation axis 113, as shown in FIG. 10B, when the fixed flange 112 contacts the stopper 108, the rotation of the drum cleaner CLk is stopped and held. That is, it is held in a state where the opening of the drum cleaner CLk faces upward. If there is no stopper 108, the drum cleaner CLk may rotate too much, causing scattering and leakage of the developer of the drum cleaner CLk or an accident to occur, but this is suppressed in the first embodiment. When the drum cleaner CLk of the first embodiment is lifted in the rotated state shown in FIGS. 10B and 11B, the rotation axis 113 comes off from the cleaner bearing 109 and the fixed flange 112 comes off from the stopper 108. Then, when the drum cleaner CLk is moved to the left, that is, in a direction along the lateral direction, the drum cleaner CLk can be separated from the photoreceptor drum Pk and detached from the front plate 101 and the rear plate 102. When attaching the drum cleaner CLk, the reverse procedure of detachment may be performed.

[0040] FIG. 12 is an explanatory view of the case where the second moving means is used in the K-color toner image forming apparatus of the first embodiment. FIG. 12A is an explanatory view of the state where the second moving means is attached, and FIG. 12B is an explanatory view of the state where the developing means is removed from the state of FIG. 12A. In the developing device Gk of Example 1, at the front end and the rear end of the developing container 121, it is screwed to the front plate 101 and the rear plate 102 with screws (not shown). In Example 1, positioning shafts 122 and 123 extending in the front-rear direction are supported at the upper left and lower right portions of the developing container 121 as an example of positioning means. The positioning shafts 122 and 123 are positioned by contacting the positioning portions 124 (only the upper rear side is shown in FIG. 9) of the front plate 101 and the rear plate 102. When detaching the developing device Gk, in Example 1, a lower lifter 131 as an example of the second moving means is used. The lower lifter 131 has a main body plate 132 as an example of the main body portion. The main body plate 132 has a pair of front and rear support portions 133 extending toward the developing device Gk. The support portions 133 can support the lower surfaces of the front end portion and the rear end portion of the developing container 121 on the upper surface.

[0041] A handle 134 as an example of operating means is supported on the main body plate 132. A lock grip 136 as an example of connecting operating means is arranged on the main body plate 132. A toggle 137 as an example of connecting means is connected to the lock grip 136. The toggle 137 moves between a state of gripping the lower positioning shaft 123 with the lower positioning shaft 123 sandwiched (see FIG. 12) and a state of releasing the lower positioning shaft 123 in conjunction with the operation of the lock grip 136. Therefore, when removing the developing device Gk, with the bottom surface of the developing container 121 placed on the upper surface of the support portion 133, the lock grip 136 is operated to grip the lower positioning shaft 123 with the toggle 137, and the handle 134 is operated to move the lower lifter 131 to the right, so that the developing device Gk can be moved to the right (lateral direction). When attaching the developing device Gk, it can be achieved by performing the reverse operation of removal.

[0042] FIG. 13 is an explanatory view of the K-color toner image forming apparatus of Example 1. FIG. 13A is an explanatory view of a state where the developing device is separated from the photosensitive drum, and FIG. 13B is an explanatory view of a state where the photosensitive drum is removed from the state of FIG. 13A. In FIG. 13, with the drum cleaner CLk and the developing device Gk separated from the photosensitive drum Pk, by removing the screws of the fixing plate 104a, the photosensitive drum Pk can be moved upward and removed. Therefore, in Example 1, unlike the developing device Gk and the drum cleaner CLk that are attached and detached in the horizontal direction, the K-color photosensitive drum Pk is attached and detached in the vertical direction. In the present specification and examples, "upward" is used in the sense of referring to an angular range of 90 degrees in total, with the 0 o'clock position of the clock (directly upward in the direction of gravity) being 0 degrees and 45 degrees to the left and right.

[0043] (Operation of Example 1) In the printer U of Example 1 having the above configuration, in the Y and M toner image forming devices UY and UM facing the upward outer surface of the intermediate transfer belt B, the photosensitive drums Py and Pm are attached and detached in the horizontal direction, and the developing devices Gy and Gm and the drum cleaners CLy and CLm are attached and detached in the horizontal direction. On the other hand, in the C and K toner image forming devices UC and UK facing the downward outer surface of the intermediate transfer belt B, the photosensitive drums Pc and Pk are attached and detached in the vertical direction, and the developing devices Gc and Gk and the drum cleaners CLc and CLk are attached and detached in the horizontal direction.

[0044] In a large printer U corresponding to high-speed printing, the photosensitive drums Py to Pk have increased in diameter, and accordingly, the developing devices Gy to Gk, the intermediate transfer belt B, etc. have become larger. Therefore, each component and unit becomes heavier, and a large space is required for installation. If four enlarged-diameter photosensitive drums Py to Pk are arranged along the upward outer surface of the intermediate transfer belt B, there is a problem that the horizontal size of the printer U becomes too large, or there is a problem that the intermediate transfer belt B also needs to be made long. In contrast, in Example 1, the toner image forming devices UY to UK are arranged two along the upward outer surface of the intermediate transfer belt B and two along the downward outer surface of the intermediate transfer belt B, suppressing an increase in the overall size of the printer U.

[0045] Here, in the four toner image forming devices UY to UK, it is common from the perspective of component commonality that the attachment / detachment structures of the photoreceptor drums Py to Pk have the same configuration. However, similar to the upper toner image forming devices UY and UM, when the photoreceptor drums Pc and Pk are pulled out laterally in the lower C-color and K-color toner image forming devices UC and UK, there is a problem that the workability of operations such as replacement work deteriorates. That is, when the height of the upper toner image forming devices UY and UM is set to a height of 120 cm from the floor as an example of a workable height, the height of the lower toner image forming devices UC and UK will be at a lower position (for example, 30 cm from the floor), and the operation of pulling out the photoreceptor drums Pc and Pk laterally needs to be performed while bending down, resulting in poor workability. On the other hand, in the upper toner image forming devices UY and UM, when the photoreceptor drums Py and Pm are attached / detached upward in the same manner as the lower C-color and K-color toner image forming devices UC and UK, it is necessary to lift the photoreceptor drums Py and Pm from a high position (120 cm from the floor) even higher, resulting in poor workability. In particular, in the large printer U, each component tends to be heavy. One photoreceptor drum Py to Pk weighs about 10 kg, the drum cleaners CLy to CLk weigh 5 to 6 kg, each developing device Gy to Gk weighs 50 kg, the writing devices LPHy to LPHk weigh 22 kg, and there is even one where the belt unit of the intermediate transfer belt B weighs 200 kg. Therefore, lifting the photoreceptor drums Py to Pk, which weigh about 10 kg, from a high position to an even higher position is a problem that places a heavy burden on the operator.

[0046] In contrast, in the first embodiment, in the upper toner image forming devices UY and UM, the photoreceptor drums Py and Pm are attached / detached laterally, and in the lower toner image forming devices UC and UK, the photoreceptor drums Pc and Pk are attached / detached upward. Therefore, compared with the case where all have the same attachment / detachment structure, the burden on the operator is reduced, and the workability of the attachment / detachment operation is improved. Also, in Example 1, the developing devices Gy to Gk are detachably attached in the horizontal direction. As described above, the developing devices Gy to Gk are very heavy compared to the photosensitive drums Py to Pk, and are parts that are too heavy for an operator to lift alone. Therefore, by adopting a configuration that allows them to be moved and detached in the horizontal direction instead of being lifted upward, the work can be done with a force weaker than lifting a heavy object, thus reducing the excessive burden on the operator. Further, in Example 1, the developing devices Gy to Gk are configured to be movable using lifters 22, 131. Therefore, the safety is improved compared to the case where the operator directly handles them without using the lifters 22, 131. In particular, even when the developing devices Gy to Gk are not replaced but only separated (shifted in position) from the photosensitive drums Py to Pk to be replaced, the work can be safely performed by using the lifters 22, 131.

[0047] Also, in Example 1, the drum cleaners CLy to CLk are configured to be detachably attached separately from the photosensitive drums Py to Pk. Therefore, compared to a configuration in which the photosensitive drums Py to Pk and the drum cleaners CLy to CLk are replaced integrally, only the parts that need to be replaced according to the individual wear conditions can be selected and replaced. Thus, although large and heavy parts tend to be costly, the overall cost (maintenance cost, running cost) can be reduced by replacing only the necessary parts. Also, in Example 1, in the upper toner image forming devices UY, UM, the drum cleaners CLy, CLm are detachably attached in the horizontal direction. Therefore, the photosensitive drums Py, Pm can be detachably attached through the path and space where the drum cleaners CLy, CLm are removed. Thus, there is no need to secure a dedicated space for removing the photosensitive drums Py, Pm, and the space is effectively utilized as a whole. Also, by moving the relatively lightweight drum cleaners CLy, CLm instead of moving the developing devices Gy, Gm which are heavier than the drum cleaners CLy, CLm, the photosensitive drums Py, Pm can be detachably attached, and the workability is improved compared to a configuration where the developing devices Gy, Gm have to be moved before the photosensitive drums Py, Pm are moved.

[0048] In particular, when the screws of the drum cleaners CLy to CLk of Example 1 are removed during replacement, the openings on the photoreceptor drum Py to Pk side face upward. Therefore, compared with the case where the openings do not face upward, scattering and leakage of the developer are suppressed during the replacement operation. Also, in Example 1, the drum cleaners CLy to CLk are stopped with the openings facing upward by the stoppers 4e and 108. When the drum cleaners CLy to CLk have a certain weight, if an operator tries to manually hold the state where the openings of the drum cleaners CLy to CLk face upward, the burden is large and there is a risk of accidents, resulting in poor workability. However, in Example 1, this problem is solved and the workability is improved.

[0049] (Modified Example) As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Modification examples (H01) to (H04) of the present invention are exemplified below. (H01) In the above embodiment, the printer U as an example of the image forming apparatus is exemplified, but the present invention is not limited thereto. For example, it can also be configured by a copying machine, a FAX, or a multifunction machine having a plurality or all of these functions.

[0050] (H02) In the above embodiment, the toner image forming apparatuses UY and UM for Y and M colors are arranged in a region where the outer surface of the intermediate transfer belt B faces upward, and the toner image forming apparatuses UC and UK for C and K colors are arranged in a region where the outer surface of the intermediate transfer belt B faces downward. However, the present invention is not limited thereto. For example, it is also applicable to a configuration in which Y, M, and C are arranged in a region facing upward and only K is arranged in a region facing downward. (H03) In the above embodiment, a configuration having four toner image forming apparatuses UY to UK is exemplified, but the present invention is not limited thereto, and it is also applicable to a configuration having two, three, or five or more toner image forming apparatuses. (H04) In the above embodiments, it is desirable to use the lifters 22 and 131, but it is also possible not to use them. That is, the lifters exemplified in the embodiments are tools for carrying out transportation work, which have the function of being able to place the developing device in a state of being attached to the image forming apparatus and being able to move it from the apparatus without lifting it, that is, the replacement support function, the lifting function for raising and lowering the developing device, and the moving function for moving the developing device using casters or the like. Using this tool is desirable because it is possible to reduce the burden on the operator. Also, it is possible to use a tool having only one or two of the support function, the lifting function, and the moving function.

Explanation of Signs

[0051] 4e, 108... Holding means, 22... First moving means, 131... Second moving means, B... Belt-like means, B1... Region where the outer surface of the belt-like means faces upward, B2... Region where the outer surface of the belt-like means faces downward, CLc, CLk... Second cleaning means, sixth detachable unit, CLy, CLm... First cleaning means, fifth detachable unit, Gc, Gk... Fourth detachable unit, Gy, Gm... Third detachable unit, Gy, Gm, Gc, Gk... Developing means, Pc, Pk... Second detachable unit, Py, Pm... First detachable unit, Py, Pm, Pc, Pk... Image holding means, SR1... First accommodating means, SR2... Second accommodating means, U... Image forming apparatus.

Claims

1. A belt-like means, a first detachable unit disposed opposite to the belt-like means in a region where the outer surface of the belt-like means faces upward, a first accommodating means for accommodating the first detachable unit and being insertable into and removable from the apparatus, a second detachable unit disposed opposite to the belt-like means in a region where the outer surface of the belt-like means faces downward, a second accommodating means for accommodating the second detachable unit and being insertable into and removable from the apparatus, a third detachable unit disposed opposite to the first detachable unit and being detachably attachable to the first accommodating means in a lateral direction, a fourth detachable unit disposed opposite to the second detachable unit and being detachably attachable to the second accommodating means in a lateral direction, the first and second detachable units having image holding means, the third and fourth detachable units having developing means, comprising: the first detachable unit being detachably attachable to the first accommodating means in a lateral direction in a state where the first accommodating means is taken out, the second detachable unit being detachably attachable to the second accommodating means in an upward direction in a state where the second accommodating means is taken out An image forming apparatus characterized by the above.

2. the third detachable unit being heavier than the first detachable unit, the fourth detachable unit being heavier than the second detachable unit, The image forming apparatus according to claim 1, characterized by comprising the above.

3. a first moving means attached to the third detachable unit when the third detachable unit is detached and moving the third detachable unit in a lateral direction, a second moving means attached to the fourth detachable unit when the fourth detachable unit is detached and moving the fourth detachable unit in a lateral direction, The image forming apparatus according to claim 2, characterized by comprising the above.

4. the first and second detachable units having image holding means, a fifth detachable unit having first cleaning means for cleaning the image holding means of the first detachable unit and being detachably attachable to the first accommodating means, a sixth detachable unit having second cleaning means for cleaning the image holding means of the second detachable unit and being detachably attachable to the second accommodating means, When the fifth detachable unit is removed, a first holding means for changing the posture of the first cleaning means in a direction in which the opening on the image holding means side of the first cleaning means faces upward and holding the first cleaning means in a posture in which the opening faces upward; When the sixth detachable unit is attached or detached, a second holding means for changing the posture of the second cleaning means in a direction in which the opening on the image holding means side of the second cleaning means faces upward and holding the second cleaning means in a posture in which the opening faces upward; The image forming apparatus according to any one of claims 1 to 3, further comprising:

5. The fifth detachable unit that is detachably attached to the first accommodating means in a lateral direction; The sixth detachable unit that is detachably attached to the second accommodating means in a lateral direction; The image forming apparatus according to claim 4, further comprising:

6. The first detachable unit that is attached or detached through a path through which the fifth detachable unit is attached or detached; The image forming apparatus according to claim 4 or 5, further comprising:

Images