Image forming device

Abstract

To prevent the occurrence of positional deviation in an image forming module to ensure rigidity.SOLUTION: An image forming apparatus 100 comprises: a photoconductor drum 101; an exposure unit 50 that irradiates the photoconductor drum 101 with light to form an electrostatic latent image on the photoconductor drum 101; a developing roller 105 that develops the electrostatic latent image to form a developer image on the photoconductor drum 101; a transfer roller 132 that transfers the developer image to a sheet S from the photoconductor drum 101; a scanner frame 11 that supports the exposure unit 50; and a transfer frame 40 that supports the transfer roller 132. The scanner frame 11 has a first surface 11s that supports the transfer frame 40, and a second surface 11e that extends in a direction intersecting the first surface 11s. The second surface 11e is formed with a through hole 11e1, and a part of the exposure unit 50 projects from the through hole 11e1.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus, such as a printer or a copier, that uses an image forming process. [Background technology]

[0002] There are known image forming devices such as printers and copiers in which multiple related components are modularized and the modules can be combined freely according to the product specifications to enable flexible product configuration (see, for example, Patent Document 1). In such image forming devices, multiple functional parts according to the product's specifications such as printing speed are prepared as modules, and can be freely attached to the device frame of the image forming device using the same interface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 06-035248 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a configuration in which modules (functional components) are mounted on an apparatus frame, the components are mounted via the apparatus frame, which can reduce the positional accuracy between the components. For example, if two modules each have a roller, the increased number of components between the two rollers can lead to misalignment between the rollers, which can cause the alignment between the two rollers to be lost. This can result in a reduction in the conveyance performance of the recording material and printing accuracy.

[0005] In addition, in the conventional device frame configuration, the device frame has a size equivalent to the image forming device main body size, thereby maintaining the rigidity of the image forming device main body. Therefore, in order to ensure the rigidity of the image forming device main body, it is necessary to increase the strength of the entire device frame. In other words, in order to prevent the image forming device main body from being twisted when the image forming device is installed and the image forming unit from being deformed and the printing accuracy from being reduced, it is necessary to ensure the rigidity of the entire device frame at a cost. In this way, in an image forming device configured by combining modules, it is desired to ensure the rigidity of the main body at a low cost while ensuring high positional accuracy between the modules.

[0006] The present invention has been made under such circumstances, and an object of the present invention is to prevent positional deviation from occurring in an image forming module and to ensure rigidity. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention has the following configuration.

[0008] (1) a photosensitive drum, an exposure unit that irradiates light onto the photosensitive drum to form an electrostatic latent image on the photosensitive drum, a developing member that develops the electrostatic latent image to form a developer image on the photosensitive drum, a transfer member that transfers the developer image from the photosensitive drum to a recording material, a scanner frame that supports the exposure unit, and a transfer frame that supports the transfer member; a cartridge including the photosensitive drum, a first side plate supporting one end of the cartridge in an axial direction of the photosensitive drum, and a second side plate supporting the other end of the cartridge in the axial direction; an image forming apparatus comprising: and contacting the transfer frame with The exposure unit has a first surface for supporting the exposure device and a second surface extending in a direction intersecting the first surface, and an opening is formed in the second surface, and a part of the exposure unit protrudes from the opening. the first side plate and the second side plate are in contact with the scanner frame and are supported by the scanner frame. 1. An image forming apparatus comprising: Effect of the Invention

[0009] According to the present invention, it is possible to prevent the image forming module from being misaligned and ensure its rigidity. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing a configuration of an image forming apparatus. [Diagram 2] FIG. 1 is a cross-sectional view of an image forming apparatus according to a first embodiment, divided into functional modules. [Diagram 3] FIG. 1 is a perspective view of an image forming apparatus according to a first embodiment, which is divided into functional modules; [Figure 4] FIG. 1 is a diagram showing a configuration of an image forming module according to a first embodiment; [Diagram 5] Exploded view of an image forming module according to the first embodiment [Figure 6] FIG. 1 is a diagram showing a part assembly configuration of an image forming module according to a first embodiment; [Figure 7] FIG. 1 is a perspective view of an image forming module and a paper feeding module according to a first embodiment; [Figure 8] FIG. 1 is a perspective view of an image forming module and a fixing module according to a first embodiment; [Figure 9] FIG. 1 is a diagram showing a configuration of an image forming module according to a first modified example of the first embodiment; [Figure 10] FIG. 13 is a diagram showing a configuration of an image forming module according to a second modified example of the first embodiment; [Figure 11] FIG. 13 is a diagram showing a configuration of an image forming module according to a third modified example of the first embodiment. [Figure 12] FIG. 13 is a perspective view of an image forming module according to a third modified example of the first embodiment; [Figure 13] FIG. 13 is a perspective view showing a configuration of an image forming module according to a fourth modified example of the first embodiment; [Figure 14] FIG. 13 is a perspective view of an image forming module according to a fourth modified example of the first embodiment; [Figure 15] FIG. 13 is a diagram showing a configuration of an image forming module according to a fourth modified example of the first embodiment; [Figure 16] FIG. 11 is a perspective view showing a configuration of an image forming module according to a second embodiment; [Figure 17] FIG. 13 is a perspective view showing a configuration of an image forming module according to a modified example of the second embodiment. [Figure 18] FIG. 13 is a diagram showing a configuration of an image forming module according to a third embodiment. [Figure 19] FIG. 13 is a diagram showing a part assembly configuration of an image forming module according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] [Configuration of image forming device] 1 is a schematic cross-sectional view showing the configuration of an image forming apparatus 100. First, the configuration and image forming operation of the image forming apparatus 100 will be described. The image forming apparatus 100 has a feeding section that feeds a sheet S, which is a recording material (recording paper), an image forming section that includes a process cartridge (hereinafter, cartridge) 102 that forms a toner image (developer image) on the sheet S, and a fixing device that fixes the toner image on the sheet S.

[0013] The cartridge 102 has a photosensitive drum 101 which is a rotatable image carrier, a charging roller 103 which charges the photosensitive drum 101, and a developing roller 105 which develops with toner (developer) an electrostatic latent image formed on the photosensitive drum 101. The photosensitive drum 101 receives drive force from one end of a rotation shaft of the photosensitive drum 101 by a driving motor (not shown) and a drive transmission unit (not shown), and is driven to rotate in the direction of the arrow in the figure (clockwise direction).

[0014] The surface of the photosensitive drum 101 is coated with an organic photoconductor layer, and the surface of the photosensitive drum 101 is charged to a uniform potential by applying a charging bias to the charging roller 103. The photosensitive drum 101, whose surface is charged to a uniform potential, is irradiated with laser light 104 corresponding to image information by an exposure unit 50, which is an exposure means. The laser light 104 scans the photosensitive drum 101, and forms an electrostatic latent image on the photosensitive drum 101. The electrostatic latent image formed on the photosensitive drum 101 is then developed with toner by the developing roller 105, and is visualized as a toner image.

[0015] On the other hand, the feeding section is composed of a feeding roller 121, a separation roller 122, a feeding tray 123, etc., and sheets S, which are recording materials, are stacked on the feeding tray 123. The sheets S are fed by the feeding roller 121 driven by a driving motor (not shown) and a drive transmission section (not shown), and only one sheet S is fed by a conveying roller pair 131 due to the frictional force of the separation roller 122. Then, the sheet S is conveyed by the conveying roller pair 131 to a transfer nip portion where the photosensitive drum 101 and a transfer roller (transfer member) 132 come into contact with each other. In the transfer nip portion, a predetermined transfer bias is applied to the transfer roller 132, so that the toner image formed on the photosensitive drum 101 is transferred to the sheet S.

[0016] The sheet S onto which the toner image has been transferred is then conveyed to a fixing device for a fixing process in which the unfixed toner image is fixed to the sheet S. In the fixing device, the sheet S is sandwiched and conveyed by a pair of fixing rollers 133 (a pressure roller and a flexible sleeve), and the toner image is fused and fixed on the sheet S by a heat and pressure process. The sheet S conveyed by the pair of fixing rollers 133 is conveyed to a pair of discharge rollers 134, and is discharged onto a discharge tray 150 and stacked thereon, completing the image formation. When double-sided printing is to be performed on the sheet S, the sheet S onto one side of which the toner image has been fixed by the fixing device is conveyed by the pair of discharge rollers 134 to a double-sided conveying path provided with a double-sided conveying roller 135 in order to print on the other side. The sheet S conveyed to the double-sided conveying path is conveyed again to the transfer nip by the double-sided conveying roller 135, and the toner image formed on the photosensitive drum 101 is transferred to the other side of the sheet S. Then, the sheet S is transported again to the fixing device, where the unfixed toner image is fixed to the sheet S by a heat and pressure process, and then the sheet S is transported to the pair of discharge rollers 134, discharged onto the discharge tray 150, and stacked, completing the image formation. EXAMPLES

[0017] [Module laminated frame] Next, the module stack frame of this embodiment will be described with reference to the drawings. The image forming apparatus 100 shown in FIG. 1 is configured by combining and mounting modules configured according to function. FIG. 2 is a cross-sectional view of each functional module included in the image forming apparatus 100 shown in FIG. 1. FIG. 3 is a perspective view showing each functional module of the image forming apparatus 100 shown in FIG. 1, excluding the duplex conveying module 75. In the following description, the upstream side in the discharge direction of the sheet S from the discharge roller pair 134 in the image forming apparatus 100 is referred to as the "rear" and the downstream side is referred to as the "front". Also, when the image forming apparatus 100 is viewed from the "front" to the "rear", the right side is referred to as the "right", the left side is referred to as the "left", the vertically upward direction is referred to as the "upper", and the vertically downward direction is referred to as the "lower". As shown in Figures 2 and 3, the image forming apparatus 100 shown in Figure 1 is broadly composed of six functional modules, namely, an image forming module 10, a paper feeding module 60, a fixing module 70, a double-sided conveying module 75, a drive module 80, and an electrical module 90.

[0018] The image forming module 10 is composed of a cartridge 102 for forming an image on a sheet S, an exposure unit 50, a scanner frame 11, a scanner reinforcement plate 12, a right side plate 20, a left side plate 30, a transfer frame 40 for supporting a transfer member 132 (not shown), and the like. The image forming module 10 will be described in detail later. The paper feed module 60 is composed of a feed roller 121 for feeding a sheet S to the image forming module 10, a separation roller 122, a feed tray 123, and the like. The fixing module 70 is composed of a fixing roller pair 133 for fixing a toner image on the sheet S and transporting the sheet S on which the toner image has been fixed, a discharge roller pair 134, and the like. The double-sided conveying module 75 is composed of a double-sided conveying roller 135 for transporting the sheet S transported by the discharge roller pair 134 to the image forming module 10, a double-sided conveying path, and the like. The drive module 80 is composed of a drive motor (not shown) for driving the above-mentioned photosensitive drum 101, the feed roller 121, and the like, a drive transmission unit (not shown), and the like. The electrical module 90 includes a control unit (not shown) that controls the image forming apparatus 100, a power supply unit (not shown), and the like.

[0019] The image forming apparatus 100 of this embodiment is configured with a module stacking frame in which necessary functional modules are attached and stacked. In such a module stacking frame, a plurality of the above-mentioned functional modules are prepared, and by attaching the necessary functional modules according to the product specifications, it is possible to correspond to a diverse product lineup.

[0020] [Image formation module configuration] Next, the image forming module 10 of this embodiment will be described with reference to Figs. 4 to 6. Fig. 4 shows the image forming module 10 of this embodiment, with (a) being a perspective view seen from the upper left, (b) being a perspective view seen from the upper right, and (c) being a cross-sectional view. Fig. 5 is an exploded view showing the components constituting the image forming module 10, and Fig. 6 is an enlarged view explaining the attachment of the components of the image forming module 10. As shown in Figs. 4 to 6, the image forming module 10 of this embodiment is composed of an exposure unit 50, a scanner frame 11, a scanner reinforcing plate 12, a right side plate 20, a left side plate 30, and a transfer frame 40.

[0021] As shown in FIG. 5, the scanner frame 11 has a first surface 11s on which a plurality of components constituting the image forming module 10 are installed, a second surface 11e having one end connected to the first surface 11s and intersecting with the first surface 11s, and a support portion 11t connected to the other end of the second surface 11e. In this embodiment, the first surface 11s is a surface extending in the horizontal direction, the second surface 11e is a surface extending in the vertical direction perpendicular to the first surface 11s, and the support portion 11t is a surface intersecting with the second surface 11e and extending in a direction away from the scanner reinforcing plate 12. Meanwhile, the scanner reinforcing plate 12 is disposed so as to overlap with the support portion 11t of the scanner frame 11. The scanner reinforcing plate 12 has a first fixing portion 12t fixed to the support portion 11t, a slope portion 12g extending in the insertion / removal direction of the cartridge 102, and a second fixing portion 12s fixed to the first surface 11s of the scanner frame 11. The scanner reinforcing plate 12 has one end connected to the first surface 11s of the scanner frame 11 and the other end connected to the second surface 11e (supporting portion 11t) of the scanner frame 11, and the scanner frame 11 and the scanner reinforcing plate 12 form a structure having a triangular cross section. Here, since the supporting portion 11t is a portion for enabling the scanner reinforcing plate 12 to be connected to the second surface 11e of the scanner frame 11, the supporting portion 11t is described as a part of the second surface 11e, and the scanner reinforcing plate 12 has the other end connected to the second surface 11e. The scanner frame 11 and the scanner reinforcing plate 12 are fixed to each other by screws (not shown) at the supporting portion 11t and the first fixing portion 12t, and at the first surface 11s and the second fixing portion 12s. This fixing is not limited to using screws, and may be done by crimping or using an adhesive.

[0022] The exposure unit 50 is fixed with at least a part of it inserted into the space surrounded by the scanner frame 11 and the scanner reinforcing plate 12. At this time, the laser light emitted from the exposure unit 50 can be irradiated onto the photosensitive drum 101 through an opening 12h provided in the inclined surface portion 12g of the scanner reinforcing plate 12. In this embodiment, a through hole 11e1 is provided in the second surface 11e, and a part of the exposure unit 50 is configured to protrude from the through hole 11e1 of the second surface 11e to the front side of the image forming module 10.

[0023] Here, the exposure unit 50 is fixed to the first surface 11s of the scanner frame 11 via two scanner stays 50a. The scanner stay 50a is provided with a boss 50b (FIG. 4(c)) which is a positioning portion, and the scanner stay 50a is fixed to the first surface 11s in a state where it is inserted into a hole provided in the first surface 11s of the scanner frame 11. This allows the exposure unit 50 to be positioned relative to the first surface 11s and ultimately the scanner frame 11, and to be arranged in a predetermined manner.

[0024] The right side plate 20 (first side plate) and the left side plate 30 (second side plate) are fixed to a first surface 11s of the scanner frame 11 and respectively constitute the right side surface and the left side surface of the image forming module 10. The right side plate 20 and the left side plate 30 respectively have an insertion / removal guide portion 20g and an insertion / removal guide portion 30g that guide the cartridge 102 when the cartridge 102, which is detachable from the image forming module 10, is attached to and detached from the image forming module 10. In other words, the cartridge 102 of the image forming module 10 is detachably attached to and detached from the image forming apparatus 100 such that both ends (one end and the other end) of the photosensitive drum 101 are guided by the insertion / removal guide portion 20g of the right side plate 20 and the insertion / removal guide portion 30g of the left side plate 30.

[0025] FIG. 6 is a diagram for explaining the attachment of components of the image forming module 10. The left side of FIG. 6 is a perspective view of the image forming module 10 shown in FIG. 4(a) and FIG. 4(b) when viewed from the lower right direction, and the right side is a perspective view of an enlarged portion surrounded by a circle on the left side. The right side plate 20 has bosses 20a and 20b. The right side plate 20 is vertically superimposed on the first surface 11s of the scanner frame 11, and the bosses 20a and 20b of the right side plate 20 are inserted into the boss holes 11a and 11b provided in the first surface 11s, thereby positioning the right side plate 20 relative to the scanner frame 11 (FIG. 6). In this state, a screw is attached to a mounting hole (not shown) of the right side plate 20 through a mounting hole 11h provided in the first surface 11s of the scanner frame 11. In this way, the right side plate 20 is fixed (screw-fastened) to the first surface 11s of the scanner frame 11. Similarly to the right side plate 20, the left side plate 30 also has bosses 30a and 30b. The left side plate 30 is positioned relative to the scanner frame 11 by overlapping the left side plate 30 vertically upward on the first surface 11s of the scanner frame 11 and inserting the bosses 30a and 30b into the boss holes provided in the first surface 11s. In this state, a screw (a bolt) is attached to a mounting hole (not shown) in the left side plate 30 via a mounting hole provided in the first surface 11s of the scanner frame 11. In this manner, the left side plate 30 is fixed (screw-fastened) to the first surface 11s of the scanner frame 11.

[0026] Further, the right side plate 20 has mounting holes 20c and 20d, and the left side plate 30 has mounting holes 30c and 30d. Meanwhile, the scanner reinforcing plate 12 has a right side portion 12a (first fastening surface) provided with mounting holes 12c and 12d for fixing to the right side plate 20, and a left side portion 12b (second fastening surface) provided with mounting holes 12e and 12f for fixing to the left side plate 30.

[0027] The right side plate 20 is attached with screws into the attachment holes 12c and 12d in the right side portion 12a of the scanner reinforcing plate 12 via the attachment holes 20c and 20d provided in the right side plate 20. In this manner, the right side plate 20 is fixed (fastened with screws) to the scanner reinforcing plate 12. Similarly, the left side plate 30 is attached with screws into the attachment holes 12e and 12f in the left side portion 12b of the scanner reinforcing plate 12 via the attachment holes 30c and 30d provided in the left side plate 30. In this manner, the left side portion 12b is fixed (fastened with screws) to the scanner reinforcing plate 12.

[0028] In this embodiment, the right side plate 20 and the left side plate 30 are made of resin. By molding the right side plate 20 and the left side plate 30 from resin, it is possible to easily form complex shapes such as the insertion / removal guide portions 20g, 30g of the cartridge 102 and mounting portions for necessary functional modules such as the drive module 80 and the electrical module 90.

[0029] The transfer frame 40 is disposed vertically above the first surface 11s of the scanner frame 11, and screws are attached to mounting holes (not shown) of the transfer frame 40 through mounting holes 11i provided in the first surface 11s. In this manner, the transfer frame 40 is fixed (screw-fastened) to the scanner frame 11. Furthermore, the transfer frame 40 has screws attached to mounting holes (not shown) provided in the transfer frame 40 through mounting holes provided in the right side plate 20 and the left side plate 30. In this manner, the right side plate 20 and the left side plate 30 are fixed (screw-fastened) to the transfer frame 40. The transfer frame 40 has a V-shaped positioning portion 40c (FIG. 4(b)), and when the cartridge 102 is mounted in the image forming apparatus 100, both ends of the photosensitive drum 101 abut against the positioning portion 40c, so that the photosensitive drum 101 and therefore the cartridge 102 are positioned. In addition, in this embodiment, the transfer frame 40 is made of resin, and has paper transport guides on the upstream side and downstream side of the photosensitive drum 101 in the transport direction of the sheet S.

[0030] A paper feed module 60 is fixed below the transfer frame 40 fixed to the scanner frame 11. FIG. 7 is a perspective view illustrating the attachment of the paper feed module 60 to the transfer frame 40 constituting the image forming module 10. FIG. 7(a) is a perspective view illustrating the state in which the paper feed module 60 is attached to the transfer frame 40, as viewed from the upper left. FIG. 7(b) is an exploded perspective view illustrating the attachment of the paper feed module 60 to the transfer frame 40. The paper feed module 60 is fixed (screw-fastened) to the transfer frame 40 with screws (not shown) in a state in which the paper feed module 60 is positioned relative to the transfer frame 40 by inserting the boss 60a of the paper feed module 60 into the boss hole 40a provided in the transfer frame 40.

[0031] Furthermore, a fixing module 70 is fixed above the transfer frame 40 fixed to the scanner frame 11. FIG. 8 is a perspective view illustrating the attachment of the fixing module 70 to the transfer frame 40 constituting the image forming module 10. FIG. 8(a) is a perspective view of the fixing module 70 attached to the transfer frame 40 as viewed from the upper right direction. FIG. 8(b) is an exploded perspective view illustrating the attachment of the fixing module 70 to the transfer frame 40. The fixing module 70 is fixed (screw-fastened) to the transfer frame 40 with screws (not shown) in a state where it is positioned relative to the transfer frame 40 by inserting a boss 40b provided on the transfer frame 40 into a boss hole 70a of the fixing module 70.

[0032] As described above, the image forming module 10 has a configuration in which the scanner reinforcing plate 12, the exposure unit 50, the right side plate 20, the left side plate 30, and the transfer frame 40 are fixed to the scanner frame 11, and the paper feed module 60 and the fixing module 70 are fixed to the transfer frame 40. More specifically, the exposure unit 50, the scanner reinforcing plate 12, the right side plate 20, the left side plate 30, and the transfer frame 40 are placed vertically from above the first surface 11s of the scanner frame 11. Therefore, each component constituting the image forming module 10 can be positioned in the height direction (vertical direction) of the image forming module 10 main body using the first surface 11s on which it is installed as a reference surface.

[0033] In this embodiment, the right side plate 20, the left side plate 30, the transfer frame 40, the scanner reinforcing plate 12, and the exposure unit 50 are installed on the scanner frame 11, which is one component constituting the reference surface of the image forming module 10. This makes it possible to minimize positional deviations of the components, and also to configure the components to be assembled based on the image forming module 10 including the scanner frame 11 and thus the exposure unit 50. As a result, deviations in the laser irradiation position on the photosensitive drum 101 of the laser light emitted from the exposure unit 50 can be minimized, and an image forming device with high print accuracy can be realized.

[0034] Furthermore, the scanner frame 11 that holds the exposure unit 50 is combined with a scanner reinforcing plate 12, and has a robust structure that is difficult to deform due to external forces. By fixing the right side plate 20, the left side plate 30, and the transfer frame 40 to the scanner frame 11, which has a robust structure with the scanner reinforcing plate 12, it is possible to reinforce only those areas where deformation would cause problems in image formation. This makes it possible to minimize, at low cost, the deviation of the laser irradiation position of the laser light emitted from the exposure unit 50 caused by twisting or distortion of the frame, and to realize an image forming device with high print accuracy.

[0035] Also, the paper feed module 60 and the fixing module 70 are positioned and fixed to the transfer frame 40, while the photosensitive drum 101 and therefore the cartridge 102 are positioned by the positioning portion 40c of the transfer frame 40. This minimizes the positional deviation of the rollers on the upstream and downstream sides of the transport direction of the sheet S relative to the photosensitive drum 101, thereby realizing stable paper transport and realizing an image forming apparatus with high printing accuracy.

[0036] As described above, according to this embodiment, it is possible to prevent the image forming module from being misaligned and ensure its rigidity.

[0037] In this embodiment, the scanner frame 11 is made up of one part, but this is not limited thereto. For example, as shown in FIG. 9, a modified configuration made up of two parts may be used. In this case, the scanner frame 11 has a first member 11S corresponding to the first surface 11s constituting the installation surface of each part of the image forming module 10, and a second member 11E corresponding to the second surface 11e disposed on the front surface of the image forming module 10. In this modified example, the first member 11S is bent in a direction intersecting with the first surface 11s and has a fixing surface 11s1 having a plurality of mounting holes. On the other hand, the second member 11E has the second surface 11e and a support portion 11t connected to the other end of the second surface 11e. Then, a screw (not shown) is attached to one end of the second surface 11e of the second member 11E through the mounting hole of the fixing surface 11s1. In this manner, the first member 11S and the second member 11E are fixed (screw-fastened). In this manner, the first member 11S and the second member 11E may form a configuration corresponding to the scanner frame 11 of the first embodiment.

[0038] In the first embodiment, the exposure unit 50 is fixed to the first surface 11s of the scanner frame 11 via two scanner stays 50a. However, the present invention is not limited to this, and the exposure unit 51 may be directly fixed to the first surface 11s of the scanner frame 11 as in the second modification shown in FIG. 10. This modification will be described with reference to FIG. 10. FIG. 10(a) is a perspective view of the image forming module 10 of this embodiment as viewed from the upper left, FIG. 10(b) is a cross-sectional view of the image forming module 10, and FIG. 10(c) is an exploded perspective view of the components constituting the image forming module 10 as viewed from the upper left. In this modification, the exposure unit 51 has a mounting portion 51a whose side surface portion facing the right side plate 20 and the left side plate 30 of the housing of the exposure unit 51 protrudes vertically downward. Furthermore, a boss 51b is provided on the mounting portion 51a, and the exposure unit 51 is fixed to the first surface 11s with the boss 51b inserted into a hole provided in the first surface 11s of the scanner frame 11. In this manner, the exposure unit 50 may be positioned relative to the first surface 11s and thus the scanner frame 11, and placed in a predetermined arrangement.

[0039] Furthermore, as shown in FIG. 11 and FIG. 12, instead of the scanner stay 50a, the first surface 11j to which the exposure unit 50 is fixed may be provided on the first surface 11s of the scanner frame 11. This modification will be described with reference to FIG. 11 and FIG. 12. FIG. 11(a) is a perspective view of the image forming module 10 of this embodiment as viewed from the lower left, FIG. 11(b) is a cross-sectional view of the image forming module 10, and FIG. 11(c) is an exploded perspective view of the components constituting the image forming module 10 as viewed from the upper left. FIG. 12 is a perspective view showing the shape of the scanner frame 11. In this modification, the first surface 11s of the scanner frame 11 is provided with a first surface 11j formed so as to protrude vertically upward, that is, inside the space surrounded by the scanner frame 11 and the scanner reinforcing plate 12. Then, the boss 50c of the scanner stay 50a is inserted into a hole 11k provided on the first surface 11j of the scanner frame 11. Then, screws (not shown) are attached to the exposure unit 50 through holes 11m provided in the first surface 11j of the scanner frame 11, and the scanner stays 50a of the exposure unit 50 are fixed (screw-fastened) to the first surface 11j. In this manner, the exposure unit 50 may be positioned relative to the first surface 11j and thus the scanner frame 11, and may be arranged in a predetermined manner.

[0040] Furthermore, in the first embodiment, the exposure unit 50 is installed on the first surface 11s of the scanner frame 11 via the scanner stay 50a, but the present invention is not limited to this. For example, as in Modification 4 shown in FIG. 13, the exposure unit 52 may be fixed to the second surface 11e of the scanner frame 11. This modification will be described with reference to FIG. 13. FIG. 13(a) is a perspective view of the image forming module 10 of this embodiment as viewed from the upper left, FIG. 13(b) is a cross-sectional view of the image forming module 10, and FIG. 13(c) is an exploded perspective view of the components constituting the image forming module 10 as viewed from the upper left.

[0041] In this modification, the exposure unit 52 is installed and fixed on the second surface 11e of the scanner frame 11 on the front side of the device. As shown in FIG. 13(c), the exposure unit 52 has an exposure section 52b, which is an exposure means for irradiating laser light according to image information, and a fixing section 52a for installing and fixing the exposure section 52b on the second surface 11e of the scanner frame 11. The fixing section 52a has mounting holes 52c and 52d for fastening to the second surface 11e. In this modification, screws are attached to the mounting holes 11c and 11d of the exposure unit 52 through the mounting holes 11c and 11d provided on the second surface 11e of the scanner frame 11. In this manner, the exposure unit 52 may be configured to be fixed (screw-fastened) to the second surface 11e of the scanner frame 11.

[0042] In the fourth modification, as shown in FIG. 14, in order to fix the exposure unit 52 to the scanner frame 11 more stably, bosses 52e and 52f may be provided on the surface of the fixing portion 52a of the exposure unit 52 facing the second surface 11e of the scanner frame 11. The bosses 52e and 52f are provided above the mounting holes 52c and 52d, but they may be provided in the vicinity. In this case, the exposure unit 52 is positioned relative to the scanner frame 11 by inserting the bosses 52e and 52f provided on the fixing portion 52a of the exposure unit 52 into the boss holes 11f and 11g provided on the second surface 11e of the scanner frame 11. Then, in this state, screws are attached to the mounting holes 52c and 52d of the exposure unit 52 through the mounting holes 11c and 11d provided on the second surface 11e of the scanner frame 11. In this manner, the exposure unit 52 is fixed (screw-fastened) to the second surface 11e of the scanner frame 11. This makes it possible to improve the accuracy of the mounting position of the exposure unit 52 relative to the scanner frame 11.

[0043] Furthermore, in the fourth modification, as shown in FIG. 15, the tip of the exposure unit 52 that emits the laser light may be supported by the scanner reinforcing plate 12 so that the exposure unit 52 is more stably installed. FIG. 15(a) is a cross-sectional view of the image forming module 10 of this embodiment, and FIG. 15(b) is an exploded perspective view of the components that constitute the image forming module 10 when viewed from the upper left direction. FIG. 15(c) is a perspective view showing the shapes of the scanner frame 11, the scanner reinforcing plate 12, and the exposure unit 52. In this configuration, one end of the exposure unit 52, which is provided with an emission port that emits the laser light to the photosensitive drum 101, is in a state of entering the opening 12h of the scanner reinforcing plate 12, and the bottom surface 52g of one end of the exposure unit 52 is supported by the lower end 12i of the opening 12h. As a result, at one end of the exposure unit 52, the lower end 12i of the opening 12h can support the load of the exposure unit 52, and the position in the up-down direction (vertical direction) can be set to a predetermined position. As a result, it is possible to improve the mounting position accuracy of the exposure unit 52 with respect to the scanner frame 11. As shown in Fig. 15, one end of the exposure unit 52 may be configured to be partially thin in the up-down direction (vertical direction) so that the one end of the exposure unit 52 can enter the opening 12h without increasing the width of the opening 12h of the scanner reinforcing plate 12. In the configuration shown in Fig. 15, the lower part of one end of the exposure unit 52 is cut out, but this is not limiting and any configuration may be used as long as the one end of the exposure unit 52 including the exit port can enter the opening 12h, and the upper part may be cut out. EXAMPLES

[0044] In the first embodiment, an example in which the scanner frame and the scanner reinforcement plate are separate parts has been described. However, this is not limited to this. In the second embodiment, an example in which the scanner frame and the scanner reinforcement plate are integrated into one part will be described.

[0045] [Image formation module configuration] This embodiment will be described with reference to Fig. 16. Fig. 16(a) is a perspective view of the image forming module 10 of this embodiment as viewed from the upper left, and Fig. 16(b) is an exploded perspective view of the components constituting the image forming module 10 as viewed from the upper left. Fig. 16(c) is an exploded perspective view of the components constituting the image forming module 10 as viewed from the upper right. The configuration of the image forming module 10 in Fig. 16 is the same as that in Fig. 4 of the first embodiment, except for a scanner frame 13 described later, and the same components are denoted by the same reference numerals, and description thereof will be omitted.

[0046] In this embodiment, the scanner frame 11 and the scanner reinforcing plate 12, which are separate parts in the first embodiment, are integrated into a single part, the scanner frame 13. That is, the scanner frame 13 has a first surface 13s on which the exposure unit 50, the right side plate 20, the left side plate 30, and the transfer frame 40 are installed, and a slope portion 13g in the insertion / removal direction of the cartridge 102, similar to the scanner frame 11 in the first embodiment. Furthermore, the scanner frame 13 has a right side portion 13a provided with mounting holes 13c and 13d for fixing the right side plate 20, and a left side portion 13b provided with mounting holes 13e and 13f for fixing the left side plate 30, similar to the scanner reinforcing plate 12 in the first embodiment. Note that since the scanner frame 13 is an integrated part of the scanner frame 11 and the scanner reinforcing plate 12, it does not have the support portion 11t and the first fixing portion 12t (FIG. 5) provided on the scanner frame 11 and the scanner reinforcing plate 12.

[0047] In this embodiment, as shown in Figs. 16(b) and 16(c), similarly to the first embodiment, the right side plate 20 is placed vertically upward on the first surface 13s of the scanner frame 13, and the bosses 20a and 20b of the right side plate 20 are inserted into the boss holes provided in the first surface 13s. In this manner, the right side plate 20 is positioned relative to the scanner frame 13. In this state, the right side plate 20 is attached to the right side surface portion 13a of the scanner frame 13 through the mounting holes 20c and 20d provided in the right side plate 20 with screws (not shown). In this manner, the right side plate 20 is fixed (screw-fastened) to the scanner frame 13. Similarly, the left side plate 30 is placed vertically upward on the first surface 13s of the scanner frame 13, and the bosses 30a and 30b are inserted into the boss holes provided in the first surface 13s, thereby positioning the left side plate 30 relative to the scanner frame 13. In this state, screws (not shown) are attached to mounting holes 13e and 13f provided in left side surface portion 13b of scanner frame 13 through mounting holes 30c and 30d provided in left side surface portion 30. In this manner, left side surface portion 30 is fixed (screw-fastened) to scanner frame 13. In this manner, right side surface portion 20 and left side surface portion 30 differ from embodiment 1 only in that right side surface portion 20 and left side surface portion 30 are fastened to right side surface portion 13a and left side surface portion 13b of scanner frame 13 instead of scanner reinforcing plate 12 of embodiment 1.

[0048] That is, the method of attaching the right side plate 20 and the left side plate 30 to the scanner frame 13 in this embodiment differs from that in the first embodiment only in the method of fastening the right side plate 20 and the left side plate 30 from the left-right direction. Therefore, as in the first embodiment, the bosses 20a and 20b of the right side plate 20 are inserted into the boss holes provided in the first surface 13s. In this way, with the right side plate 20 positioned relative to the scanner frame 13, screws (not shown) are attached to the attachment holes (not shown) of the right side plate 20 through the attachment holes provided in the first surface 11s. Furthermore, the bosses 30a and 30b are inserted into the boss holes provided in the first surface 13s. In this way, with the left side plate 30 positioned relative to the scanner frame 13, screws (not shown) are attached to the attachment holes 13e and 13f provided in the attachment holes (not shown) of the left side plate 30 through the attachment holes provided in the first surface 11s. In this way, as in the first embodiment, the right side plate 20 and the left side plate 30 can be fixed (screw-fastened) to the scanner frame 13.

[0049] As described above, the right side plate 20, the left side plate 30, the transfer frame 40, and the exposure unit 50 are installed so as to be placed vertically above the first surface 13s. Therefore, each component constituting the image forming module 10 can be positioned in the height direction (vertical direction) of the image forming module 10 body with the first surface 13s on which it is installed as a reference surface, and the positional deviation of each component can be minimized. In this embodiment, the right side plate 20, the left side plate 30, the transfer frame 40, and the exposure unit 50 are installed on the scanner frame 13, which is one component constituting the reference surface of the image forming module 10. This makes it possible to minimize the positional deviation of each component, and also to configure the image forming module 10 equipped with the scanner frame 13 and thus the exposure unit 50 as a reference, in which each component is assembled. As a result, the deviation of the laser irradiation position on the photosensitive drum 101 of the laser light emitted from the exposure unit 50 can be minimized, and an image forming device with high printing accuracy can be realized. Furthermore, the scanner frame 13 that holds the exposure unit 50 is combined with an inclined surface 13g corresponding to the scanner reinforcing plate 12 of the first embodiment, and is configured to be robust so as to be resistant to deformation due to external forces. By fixing the right side plate 20, the left side plate 30, and the transfer frame 40 to the scanner frame 13, which is configured robust with the inclined surface 13g, it is possible to reinforce only the areas where deformation would cause problems in image formation. This minimizes the deviation in the laser irradiation position of the laser light emitted from the exposure unit 50 caused by twisting or distortion of the frame, and makes it possible to realize an image forming device with high print accuracy.

[0050] As described above, according to this embodiment, it is possible to prevent the image forming module from being misaligned and ensure its rigidity.

[0051] As shown in FIG. 17, a modified example may be used in which a bent shape extending vertically is added to the scanner frame 13 in order to increase the number of fastening portions between the right side plate 20 and the left side plate 30. In this modified example, the scanner frame 13 has a right side portion 13h and a left side portion 13i that are connected to the first surface 13s and protrude rearward from the left and right ends. The right side portion 13h has mounting holes 13j and 13k for fastening to the right side plate 20, and the left side portion 13i has mounting holes 13l and 13m for fastening to the left side plate 30. Screws (not shown) are attached to the mounting holes 13c and 13d provided in the right side portion 13a via the mounting holes 20c and 20d of the right side plate 20, as well as to the mounting holes 20e and 20f provided in the right side plate 20 via the mounting holes 13j and 13k of the right side portion 13h. This allows the scanner frame 13 and the right side plate 20 to be more firmly fixed (screw-fastened). Similarly, screws (not shown) are attached to the mounting holes 13e and 13f provided in the left side surface portion 13b through the mounting holes 30c and 30d of the left side surface portion 30, and to the mounting holes 30e and 30f provided in the right side surface portion 30 through the mounting holes 13l and 13m of the left side surface portion 13i. This allows the scanner frame 13 and the left side surface portion 30 to be more firmly fixed (screw-fastened). In this manner, the configuration according to the modified example can obtain the same effect as that of the second embodiment, and further suppresses deformation of the first surface 13s and thus the scanner frame 13 by having the right side surface portion 13h and the left side surface portion 13i protruding rearward from the first surface 13s of the scanner frame 13. Furthermore, by using the right side surface portion 13h to fix the scanner frame 13 and the right side surface portion 20, and using the left side surface portion 13i to fix the scanner frame 13 and the left side surface portion 30, it is possible to suppress the positional deviation of the right side surface portion 20 and the left side surface portion 30 relative to the scanner frame 13. EXAMPLES

[0052] In the first and second embodiments, the right side plate 20 is positioned relative to the scanner frame 11 by inserting the bosses 20a and 20b provided on the bottom surface of the right side plate 20 into the holes 11a and 11b provided on the first surface 11s of the scanner frame 11. Similarly, the left side plate 30 is positioned relative to the scanner frame 11. However, the present invention is not limited to this. The bosses 20a and 20b provided on the bottom surface of the right side plate 20 in the first embodiment may not be provided, and the first surface 18s of the scanner frame 18 may not have boss holes into which the bosses 20a and 20b are inserted. Similarly, the bosses 30a and 30b provided on the bottom surface of the left side plate 30 in the first embodiment may not be provided, and the first surface 18s of the scanner frame 18 may not have boss holes into which the bosses 30a and 30b are inserted. In the third embodiment, an embodiment in which the positioning is performed by inserting the protrusions provided on the scanner frame into the holes provided on the right side plate and the left side plate will be described.

[0053] [Image formation module configuration] This embodiment will be described with reference to FIGS. 18 and 19. FIG. 18(a) is a perspective view of the image forming module 10 of this embodiment when viewed from the upper left, and FIG. 18(b) is a perspective view of the image forming module 10 of this embodiment when viewed from the upper right. Also, FIG. 18(c) is an exploded perspective view of the components constituting the image forming module 10 when viewed from the upper left. FIG. 19(a) is a perspective view showing the shapes of the right side plate 21, the left side plate 31, and the scanner frame 18 shown in FIG. 18. FIG. 19(b) is a perspective view explaining the assembled state of the right side plate 21 and the scanner frame 18 when the image forming module 10 of this embodiment is viewed from the right side. Also, FIG. 19(c) is a perspective view showing an enlarged view of the circled portion of FIG. 19(b). The image forming module 10 of this embodiment is the same as that of the first embodiment except for the right side plate 21, the left side plate 31, and the scanner frame 18. In this embodiment, the same components as those of the first embodiment are described using the same reference numerals, and the description thereof will be omitted.

[0054] As in the first embodiment, the scanner frame 18 has a first surface 18s on which a plurality of components constituting the image forming module 10 are mounted, a second surface 18e having one end connected to the first surface 18s and intersecting with the first surface 18s, and a support portion 18t connected to the other end of the second surface 18e. In this embodiment, the first surface 18s is a surface extending in the horizontal direction, the second surface 18e is a surface extending in the vertical direction perpendicular to the first surface 18s, and the support portion 18t is a surface intersecting with the second surface 18e and extending in a direction away from the scanner reinforcing plate 12. The scanner reinforcing plate 12 has one end connected to the first surface 18s of the scanner frame 11 and the other end connected to the second surface 18e (support portion 18t) of the scanner frame 18, and the scanner frame 11 and the scanner reinforcing plate 12 form a structure having a triangular cross section. The scanner frame 18 and the scanner reinforcing plate 12 are fixed with screws (not shown) at the support portion 18t and the first fixing portion 12t, and at the first surface 18s and the second fixing portion 12s.

[0055] The scanner frame 18 according to this embodiment has three protrusions 18n (first protrusions) protruding to the right from the right end and three protrusions 18p (second protrusions) protruding to the left from the left end on the first surface 18s and the second surface 18e. More specifically, the protrusions 18n are provided at the right end of the scanner frame 18, two of which are connected to the first surface 18s and extend in the extension direction of the first surface 18s, and one of which is connected to the second surface 18e and extends in the extension direction of the second surface 18e. On the other hand, the protrusions 18p are provided at the left end of the scanner frame 18, two of which are connected to the first surface 18s and extend in the extension direction of the first surface 18s, and one of which is connected to the second surface 18e and extends in the extension direction of the second surface 18e.

[0056] The scanner frame 18 has three fastening surfaces 18q (third fastening surfaces) with screw holes formed by bending the right end of the first surface 18s and the second surface 18e, and three fastening surfaces 18r (fourth fastening surfaces) with screw holes formed by bending the left end of the first surface 18s and the second surface 18e. More specifically, the fastening surfaces 18q are provided at the right end of the scanner frame 18, two of which are connected to the first surface 18s and extend in a direction intersecting with the first surface 18s, and one of which is connected to the second surface 18e and extends in the extension direction of the second surface 18e. Meanwhile, the fastening surfaces 18p are provided at the left end of the scanner frame 18, two of which are connected to the first surface 18s and extend in a direction intersecting with the first surface 18s, and one of which is connected to the second surface 18e and extends in a direction intersecting with the second surface 18e.

[0057] The right side plate 21 has three holes 21n as positioning portions, and the three protrusions 18n protruding to the right from the right end of the scanner frame 18 are inserted into the holes 21n to position the right side plate 21 relative to the scanner frame 18. In this state, the fastening surface 18q provided on the scanner frame 18 is placed on the right side plate 21, and screws are attached to the screw holes of the fastening surface 18q through the mounting holes (not shown) of the right side plate 21. In this way, the right side plate 21 is fixed (screw-fastened) to the scanner frame 18. Similarly, the left side plate 31 has three holes 31n as positioning portions, and the three protrusions 18p protruding to the left from the left end of the scanner frame 18 are inserted into the holes 31n to position the left side plate 31 relative to the scanner frame 18. In this state, the fastening surface 18r provided on the scanner frame 18 is placed over the left side plate 31, and screws are inserted into the screw holes of the fastening surface 18r through the mounting holes (not shown) of the left side plate 31. In this manner, the left side plate 31 is fixed (screw-fastened) to the scanner frame 18.

[0058] The configuration of the scanner frame 18, excluding the protrusions 18n, 18p between the right side plate 21 and the left side plate 31, and the fastening surfaces 18q, 18r, is the same as in the first embodiment, and the description thereof will be omitted here. For example, the configuration in which the transfer frame 40 is fixed to the first surface 18s, and the right side plate 21 and the left side plate 31 are fixed (screw-fastened) to the transfer frame 40, and the configuration in which the exposure unit 50 is fixed to the scanner frame 18 by two scanner stays 50a are the same as in the first embodiment. In the above-mentioned embodiment, the fastening is performed by screws (bis), but the fastening is not limited to screws. For example, the fastening may be performed by rivets instead of screws, or by spot welding.

[0059] As described above, the image forming module 10 is configured by fixing the scanner reinforcement plate 12, the exposure unit 50, the right side plate 21, the left side plate 31, and the transfer frame 40 to the scanner frame 18, and fixing the paper feed module 60 and the fixing module 70 to the transfer frame 40. Therefore, each component constituting the image forming module 10 can be positioned with the scanner frame 18 as a reference. This makes it possible to minimize the positional deviation of each component, and also makes it possible to configure the image forming module 10 including the scanner frame 18 and the exposure unit 50 as a reference with each component assembled. In particular, in this embodiment, the positioning is performed by inserting the protrusion 18n provided on the scanner frame 18 into the hole 21n provided on the right side plate 21, and the protrusion 18p into the hole 31n provided on the left side plate 31. This minimizes the positional deviation of the right side plate 21 and the left side plate 31 with respect to the scanner frame 18, and allows the right side plate 21 and the left side plate 31 to be stably fixed. As a result, deviation of the laser irradiation position on the photosensitive drum 101 of the laser light emitted from the exposure unit 50 can be minimized, and an image forming apparatus with high printing accuracy can be realized.

[0060] Furthermore, the scanner frame 18 that holds the exposure unit 50 is combined with the scanner reinforcing plate 12, and has a robust structure that is difficult to deform due to external forces. By fixing the right side plate 21, the left side plate 31, and the transfer frame 40 to the scanner frame 18, which has a robust structure with the scanner reinforcing plate 12, it is possible to reinforce only those areas where deformation would cause problems in image formation. This makes it possible to minimize, at low cost, the deviation of the laser irradiation position of the laser light emitted from the exposure unit 50 caused by twisting or distortion of the frame, and to realize an image forming device with high print accuracy.

[0061] Also, the paper feed module 60 and the fixing module 70 are positioned and fixed to the transfer frame 40, while the photosensitive drum 101 and therefore the cartridge 102 are positioned by the positioning portion 40c of the transfer frame 40. This minimizes the positional deviation of the rollers on the upstream and downstream sides of the transport direction of the sheet S relative to the photosensitive drum 101, thereby realizing stable paper transport and realizing an image forming apparatus with high printing accuracy.

[0062] As described above, according to this embodiment, it is possible to prevent the image forming module from being misaligned and ensure its rigidity. [Explanation of symbols]

[0063] 10 Image forming module 11 Scanner Frame 50 Exposure Unit 60 Paper Feeding Module 70 Fixing module 101 Photosensitive drum

Claims

1. A photosensitive drum; an exposure unit that irradiates the photosensitive drum with light to form an electrostatic latent image on the photosensitive drum; a developing member for developing the electrostatic latent image to form a developer image on the photosensitive drum; a transfer member for transferring the developer image from the photosensitive drum to a recording material; a scanner frame supporting the exposure unit; A transfer frame supporting the transfer member; a cartridge including the photosensitive drum; a first side plate that supports one end of the cartridge in an axial direction of the photosensitive drum; a second side plate supporting the other end of the cartridge in the axial direction; An image forming apparatus comprising: the scanner frame has a first surface that contacts the transfer frame and supports the transfer frame, and a second surface that extends in a direction intersecting the first surface; an opening is formed in the second surface, and a portion of the exposure unit protrudes from the opening; the first side plate and the second side plate are in contact with the scanner frame and are supported by the scanner frame; 1. An image forming apparatus comprising:

2. 2. The image forming apparatus according to claim 1, wherein the direction in which the exposure unit irradiates light intersects with the first surface.

3. 3. The image forming apparatus according to claim 1, wherein the first side panel and the second side panel each have a first boss, and are positioned by inserting the first boss into a first hole provided on the first surface of the scanner frame.

4. The first side plate has a first insertion / removal guide, The second side plate has a second insertion / removal guide, An image forming apparatus according to any one of claims 1 to 3, characterized in that the cartridge, whose insertion is guided by the first insertion / removal guide of the first side plate and the second insertion / removal guide of the second side plate, abuts against the transfer frame and is positioned.

5. the first surface supports the first side plate and the second side plate; 5. The image forming apparatus according to claim 4, wherein the second surface supports the exposure unit.

6. 6. The image forming apparatus according to claim 1, further comprising a scanner reinforcing plate connected to the other end of the first surface and the other end of the second surface.

7. 7. The image forming apparatus according to claim 6, wherein one side of the scanner reinforcing plate in the axial direction is fixed to the first side plate, and the other side of the scanner reinforcing plate in the axial direction is fixed to the second side plate.

8. the scanner reinforcing plate has an opening through which the light emitted from the exposure unit can be irradiated onto the photosensitive drum, 8. The image forming apparatus according to claim 6, wherein the exposure unit is supported by the opening.

9. the scanner frame has a first protruding portion protruding in one direction from one end and a second protruding portion protruding in the other direction from the other end, the first protrusion is inserted into a hole provided in the first side plate, and the first side plate is positioned relative to the scanner frame; 8. The image forming apparatus according to claim 1, wherein the second protrusion is inserted into a hole provided in the second side plate, and the second side plate is positioned relative to the scanner frame.

10. the first surface has a protrusion protruding upward from the first surface, 10. The image forming apparatus according to claim 1, wherein the exposure unit is supported by the protruding portion.

Images