JP2020046685A - Image forming apparatus - Google Patents

Abstract

To provide a configuration for efficiently utilizing a space in an apparatus.SOLUTION: An image forming apparatus includes a first frame F1 and a second frame F2 which are arranged in a rotation axis direction X of an image carrier, and face each other across an image forming section and a stacking unit 19. The stacking unit 19 is disposed below the image forming section. The first frame F1 includes a first member 40a having a first side surface S1 facing the image forming section, and a second member 40b fixed to the first member 40a and having second side surfaces S2a and S2b facing the stacking unit 19. The second frame F2 includes a third side surface S3 facing the image forming section and the stacking unit 19. At least a part of the second side surface is disposed in a position different from the first side surface S1 with respect to the rotation axis direction of the image carrier.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an electrophotographic image forming apparatus such as an LBP, a copying machine, and a facsimile.

  As a frame structure of an image forming apparatus, there is a structure using two side plates opposed to each other with a photoreceptor interposed therebetween, as disclosed in Japanese Patent Application Laid-Open No. H11-163,837. As described above, in the image forming apparatus having the frame structure including the two side plates, the image forming unit including the photosensitive member between the two side plates and the stacking unit configured to detachably mount the sheet to be conveyed to the image forming unit, which is detachable from the apparatus main body. A unit (paper feed cassette) is arranged.

JP 2009-128506

  Incidentally, the distance between the two side plates is generally determined by the length of the widest object among the members sandwiched between the two side plates. For example, in the case of a configuration that has a tray that supports a cartridge and that can be inserted and removed, as in Patent Document 1, it is necessary to arrange the tray and its insertion / extraction mechanism between two side plates. However, the minimum width of the sheet cassette is not always the same as the minimum width of the tray and its insertion / extraction mechanism. For this reason, when the distance between the two side plates is set so that the tray, the insertion / extraction mechanism, and the paper feed cassette are accommodated between the two side plates, the portion between the two side plates and the tray and the insertion / extraction mechanism or the two side plates An empty space is created between the paper cassette and the paper cassette. For this reason, the volume of the image forming apparatus is increased more than necessary by the amount of the empty space, and there is a possibility that downsizing of the image forming apparatus may be hindered.

  Accordingly, an object of the present invention is to provide an image forming apparatus capable of effectively utilizing a space in the apparatus in view of the above-described problem.

  Therefore, the present invention provides an image forming unit including a rotatable image carrier, which transfers a toner image formed on the image carrier to a recording medium, and which is detachably attached to an apparatus main body and conveys the image to the image forming unit. The image forming unit, comprising: a loading unit for loading a recording medium; and a first frame and a second frame arranged in the rotation axis direction of the image carrier and opposed to each other with the image forming unit and the loading unit interposed therebetween. In the image forming apparatus in which the loading unit is disposed below the first unit, the first frame is fixed to the first member having a first side surface facing the image forming unit, and the first frame is fixed to the loading unit. A second member having a second side surface facing the second member, wherein the second frame has a third side surface facing the image forming section and the stacking unit, and the second frame has a second side with respect to a rotation axis direction of the image carrier. side At least in part, characterized in that it is arranged at a position different from the first side surface.

  According to the present invention, the space in the image forming apparatus can be effectively utilized.

FIG. 2 is a perspective view of the image forming apparatus. FIG. 2 is a schematic sectional view of the image forming apparatus. FIG. 2 is a perspective view of the image forming apparatus. FIG. 2 is a perspective view of the image forming apparatus. FIG. 2 is a perspective view illustrating a frame structure of the image forming apparatus. FIG. 2A is a diagram illustrating a frame structure of an image forming apparatus and members supported by the frame structure when viewed from a front side. FIG. 2B is a diagram illustrating the frame structure of the image forming apparatus and members supported by the frame structure when viewed from above. (A) The figure which looked at the frame structure of the comparative example, and the member supported by it from the front side. (B) The figure which looked at the frame structure of the comparative example, and the member supported by it from the front side. The figure which looked at the frame structure of the comparative example, and the member supported by it from the upper side. FIG. 2 is a partial perspective view of a frame structure of the image forming apparatus. FIG. 7 is a partial perspective view of a frame structure of a comparative example. FIG. 2 is a front view of a frame structure of the image forming apparatus and members supported by the frame structure.

<First embodiment>
(Overall schematic configuration of image forming apparatus)
An overall schematic configuration of the image forming apparatus will be described. 1 is an external perspective view of the image forming apparatus 100, and FIG. 2 is a schematic cross-sectional view of the image forming apparatus 100 when viewed in the rotation axis direction of the photosensitive drum 1.

  The image forming apparatus 100 is a four-color full-color laser printer using an electrophotographic process. The image forming apparatus 100 forms a toner image on a sheet-like recording medium (paper) based on an image signal input from an external host device (not shown) such as a personal computer, an image reader, and a partner facsimile machine.

  In the following description, the “front (front)” of the image forming apparatus (also referred to as the apparatus main body) 100 is the side on which the door 31 of the apparatus main body 100 is provided. "Back" is the opposite side of "front". "Left" is the left side of the apparatus main body 100 as viewed from the "front" side of the apparatus main body 100, and "Right" is the right side of the apparatus main body 100 as viewed from the "front" side of the apparatus main body 100.

  In the apparatus main body 100, four cartridges P (PY, PM, PC, PK) are arranged in a substantially horizontal direction from the rear to the front. Each cartridge P has the same configuration except that the colors of the stored toner are different, and operates similarly. Each of the cartridges P includes a photosensitive drum (photosensitive member) 1 as a first image carrier, a charger 2 as a process unit acting on the photosensitive drum 1, a developing device 3, a cleaning device 4, and a photosensitive drum. The apparatus includes a drum 5 and a frame 5 that supports a process unit. In a state where the cartridge P is mounted on the apparatus main body 100, the photosensitive drum 1 included in the cartridge P is rotatably supported. The charger 2 includes a charging roller. The developing device 3 includes a developing roller 3a, and a developer (toner) is stored inside the developing device 3. The cleaning device 4 includes a cleaning blade that contacts the photosensitive drum 1.

  The first cartridge PY contains yellow (Y) toner in the developing device 3, and forms a yellow toner image on the surface of the photosensitive drum 1. The second cartridge PM contains magenta (M) toner in the developing device 3 and forms a magenta toner image on the surface of the photosensitive drum 1. The third cartridge PC contains a cyan (C) toner in the developing device 3 and forms a cyan toner image on the surface of the photosensitive drum 1. The fourth cartridge PK stores black (K) toner in the developing device 3 and forms a black toner image on the surface of the photosensitive drum 1.

  Above the four cartridges P (PY, PM, PC, PK), a laser scanner unit 11 is provided. The scanner unit 11 emits, toward each photosensitive drum 1, a laser beam L modulated based on image information of each color input from an external host device. Each laser beam passes through the opening 6 provided on the upper surface of the frame 5 of each cartridge P, reaches the surface of the photosensitive drum 1, and scans and exposes the surface of the photosensitive drum 1 with the laser beam L.

  A belt unit 12 is disposed below the four cartridges P (PY, PM, PC, PK). The belt unit 12 includes a flexible endless belt 13 serving as an intermediate transfer member (second image carrier), and a driving roller that stretches and circulates (rotates) the belt 13. 14 and a tension roller 15. The drive roller 14 is disposed on the rear side in the apparatus main body 100. The tension roller 15 is disposed on the front side in the apparatus main body 100. The rotation axis of the belt 13 that circulates (rotates) is the rotation axis of the drive roller 14 or the rotation axis of the tension roller 15. The rotation axis of the driving roller 14 and the rotation axis of the tension roller 15 are parallel to the rotation axis of the photosensitive drum 1.

  The lower surface of the photosensitive drum 1 of each cartridge is in contact with the upper surface of the ascending belt portion of the belt 13. Four primary transfer rollers 17 are disposed inside the belt 13 so as to face the photosensitive drum 1 of each cartridge via an ascending belt portion. The secondary transfer roller 22 is in contact with the drive roller 14 via the belt 13.

  Below the belt unit 12, a paper feed unit 18 is provided. The paper supply unit 18 includes a paper supply cassette 19, a paper supply roller 60, a transport roller 20, and a separation roller 21. The paper feed cassette 19 is a loading unit for storing and loading a recording medium (paper) S, and is detachable from the apparatus main body 100 by being inserted and removed from the front side of the apparatus main body 100. The paper feed roller 60 and the transport roller 20 are transport members that transport the recording medium from inside the paper feed cassette 19.

  A fixing device 23 and a pair of paper discharge rollers 24 are disposed in the upper portion on the rear side in the apparatus main body 100. The upper surface of the apparatus main body 100 is a paper discharge unit 25. The fixing device 23 has a fixing film assembly 23a and a pressure roller 23b. The discharge roller pair 24 includes a discharge roller 24a and a discharge roller 24b.

  When the cartridge P is mounted on the apparatus main body 100, the frame 5 and the photosensitive drum 1 of the cartridge P are positioned at predetermined positions by positioning means (not shown) provided on the apparatus main body 100. In this state, the drive input section of each cartridge P is connected to the drive mechanism 52 (see FIG. 6) provided in the apparatus main body 100, and the electrical contacts of each cartridge P are electrically connected to the high voltage power supply section 53 (see FIG. 6). doing. Therefore, the photosensitive drum 1 and other process means are in an operable state.

  Each of the cartridges P and the belt unit 12 described above correspond to an image forming unit for transferring the toner image carried on the photosensitive drum 1 and the belt 13 to a recording medium. The recording medium loaded on the paper feed cassette 19 is conveyed to a secondary transfer section (secondary transfer nip section) between the secondary transfer roller 22 and the belt 13 in the image forming section.

(Image forming operation)
The image forming operation for forming a full-color image is as follows. The photosensitive drums 1 of the first to fourth cartridges PY, PM, PC, and PK are driven to rotate at a predetermined control speed. The belt 13 is also driven to rotate at a speed corresponding to the speed of the photosensitive drum 1. The scanner unit 11 is also driven. In synchronization with this drive, the charging roller 2 uniformly charges the surface of the photosensitive drum 1 to a predetermined polarity and potential at a predetermined control timing in each cartridge. The scanner unit 11 scans and exposes the surface of each photosensitive drum 1 with a laser beam L modulated according to an image signal of each color. Thus, an electrostatic latent image corresponding to the image signal of the corresponding color is formed on the surface of each photosensitive drum 1. Then, a toner image is formed on the photosensitive drum 1 by attaching toner to the electrostatic latent image by the developing roller 3a.

  The toner image corresponding to the yellow component of the full-color image is formed on the photosensitive drum 1 of the cartridge PY by the above-described electrophotographic image forming process operation, and the toner image is primarily transferred onto the belt 13. Similarly, a magenta toner image corresponding to the magenta component of the full-color image is formed on the photosensitive drum 1 of the cartridge PM, and the toner image is superimposed on the yellow toner image already transferred onto the belt 13. Primary transfer. Similarly, a cyan toner image corresponding to the cyan component of the full-color image is formed on the photosensitive drum 1 of the cartridge PC, and the toner image is converted to the yellow and magenta toner images that have already been transferred onto the belt 13. It is superimposed and primary transferred. A black toner image corresponding to the black component of the full-color image is formed on the photosensitive drum 1 of the cartridge PC, and the toner image is converted into a yellow + magenta + cyan toner image already transferred on the belt 13. It is superimposed and primary transferred. Thus, a full color toner image of yellow + magenta + cyan + black is formed on the belt 13. The primary transfer of the toner image of each color is based on the primary transfer bias voltage applied to the primary transfer roller 17.

  In each cartridge P, the toner attached to the surface of the photosensitive drum 1 after the primary transfer is removed from the surface of the photosensitive drum 1 by the cleaning device 4.

  On the other hand, the feed roller 60 is driven at a predetermined control timing. As a result, the sheet S, which is a recording medium loaded on the sheet cassette 19, is separated and fed one by one, and passes through the transport roller 20, the separation roller 21, the transport roller pairs 61 a, 61 b and the secondary transfer roller 22. And a belt 13 (secondary transfer nip). A secondary transfer bias voltage is applied to the secondary transfer roller 22. Thus, the toner images of four colors superimposed on the belt 13 are collectively transferred onto the surface of the sheet S while the sheet S is being nipped and conveyed.

  The sheet S is separated from the surface of the belt 13 and introduced into the fixing device 23, where the sheet S is heated and pressed at the fixing nip. As a result, the toner image is fixed on the sheet. Then, the paper S exits the fixing device 23 and is discharged onto a paper discharge unit 25 by a paper discharge roller pair 24.

  The toner on the surface of the belt 13 after the secondary transfer is electrostatically attached to the surface of the photosensitive drum 1 in the primary transfer portion of the cartridge PY, and is removed by the cleaning device 4.

(Replace the cartridge)
Next, replacement of each cartridge P will be described. 3 and 4 are perspective views of the image forming apparatus 100. When removing each cartridge P from the apparatus main body 100, first, as shown in FIG. 3, the door 31 is opened, and a handle 35a of the tray 35 as a movable member that can move while supporting each cartridge P is exposed. In the state shown in FIG. 3, the tray 35 is located inside the apparatus main body 100. However, when the user grips the handle 35a and pulls out the tray 35, as shown in FIG. Can be moved to the position. When the tray 35 is at a position outside the apparatus main assembly 100, each cartridge P can be removed from the tray 35 and replaced. When each of the cartridges P is mounted on the apparatus main assembly 100, an operation reverse to the above operation may be performed.

  The moving direction of the tray 35 is a direction orthogonal to the rotation axis direction of the photosensitive drum 1 (the longitudinal direction of the cartridge P). Further, the tray 35 may directly or indirectly support the photosensitive drum 1. That is, the tray 35 may be configured to indirectly support each photosensitive drum 1 via the frame 5 of each cartridge P, or may be configured to directly support the photosensitive drum 1 by the tray 35. .

(Frame structure)
FIG. 5 is a perspective view of the frame structure of the image forming apparatus 100. Hereinafter, the axial direction of the photosensitive drum 1 (the longitudinal direction of the cartridge P) is defined as the X direction, and the vertical direction is defined as the Z direction. The image forming apparatus 100 includes, as members constituting the frame structure, a first frame F1 on the right side of the apparatus main body 100, a second frame F2 on the left side, and two stay members connecting the first and second frames F1 and F2. . The first frame F1 includes a right side plate (first member) 40a and a paper feed unit frame (second member) 40b, the second frame F2 includes a left side plate 41, and two stay members include a bottom plate 42 and a scanner stay 43. It is. The right side plate 40a, the sheet feeding unit frame 40b, the left side plate 41, the bottom plate 42, and the scanner stay 43 are plate-shaped metal members. The paper feed unit frame 40b is a member made of resin. The right side plate 40a is arranged in a portion of the second frame F2 facing the image forming unit (each cartridge P, the belt unit 12) in the X direction. The paper feed unit frame 40b is arranged in a portion of the second frame F2 that faces the paper feed cassette 19 below the image forming unit in the X direction.

  The right side plate 40a and the left side plate 41 are fixed to the bottom plate 42 and the scanner stay 43, respectively, in a state where they abut on the bottom plate 42 and the scanner stay 43 in the X direction. As described above, the distance between the right side plate 40a and the left side plate 41 in the X direction is determined by colliding with the bottom plate 42 and the scanner stay 43, respectively.

  The positioning of the right side plate 40a and the sheet feeding unit frame 40b will be described. The right side plate 40a is formed with two holes 44a penetrating through the right side plate 40a in the X direction formed by punching in the X direction by press working. On the other hand, the paper supply unit frame 40b is provided with two convex portions (bosses) 44b protruding toward the right side plate 40a in the X direction. Then, the sheet feeding section frame 40b is fixed to the right side plate 40a in a state where the two protrusions 44b are inserted into the two holes 44a, and the positions thereof are determined. When the two convex portions 44b abut against the inner peripheral surfaces of the two holes 44a, respectively, the position of the paper feed unit frame 40b with respect to the right side plate 40a is determined in the Z direction and the direction orthogonal to the Z direction and the X direction. I have. In the X direction, the position is determined by abutting a not-shown abutment provided on the sheet supply unit frame 40b against the right side plate 40a.

  6A and 6B are diagrams illustrating a frame structure of the image forming apparatus 100 and members supported by the frame structure. FIG. 6A is a diagram viewed from the front side, and FIG. 6B is a diagram viewed from above. The cartridge P, the belt unit 12, and the tray 35 are arranged between the right side plate 40a and the left side plate 41. The paper cassette 19 is disposed between the paper frame 40 b and the left side plate 41.

  The right side plate 40a has a first side surface S1 orthogonal to the X direction, and supports the driving mechanism 52 of the cartridge P on the opposite side (outside) of the cartridge P on the first side surface S1. The driving mechanism 52 is an image carrier driving unit including a motor and a gear train for driving the photosensitive drum 1 and the belt 13 to rotate.

  The paper feed unit frame 40b includes two second side surfaces S2a and S2b orthogonal to the X direction. The two second side surfaces S2a and S2b are arranged at different positions in the X direction. The second side surface S2a is closer to the sheet cassette 19 than the first side surface, and the second side surface S2b is opposite to the sheet cassette 19 from the first side. Are located.

  The paper feed unit frame 40b movably supports the paper feed cassette 19 on the paper feed cassette 19 side (inside) of the second side surface S2a, and supports a guide unit (supporting unit) 54a that guides the movement of the paper feed cassette 19. I do. On the side (inside) of the sheet cassette 19 on the second side surface S2b, there is provided a motor and a gear train for driving the conveying members (the sheet feeding roller 60 and the conveying roller 20) and the like to operate the sheet feeding unit 18. The paper drive unit (transport member drive unit) 50 is supported. A power supply unit 51 functioning as a low-voltage power supply unit (primary power supply unit) for supplying electric power to the image forming apparatus 100 is provided on a side (outside) of the second side surface S2a and the second side surface S2b opposite to the sheet cassette 19. I support. On the side (outside) of the second side surface S2a and the second side surface S2b opposite to the sheet cassette 19, a wall portion W protruding from the second side surface S2a, S2b in the X direction to the opposite side (outside) of the sheet cassette 19. Is formed. The wall portion W is disposed so as to surround the power supply portion 51 when viewed in the X direction, and since the sheet feeding portion frame 40b is a member made of flame-retardant resin, the wall portion W and the second side surfaces S2a and S2b are provided. Function as a fire enclosure.

  The left side plate 41 includes a third side surface S3 orthogonal to the X direction, and supports a high-voltage power supply unit (secondary power supply) 53 on a side (outside) of the third side surface S3 opposite to the cartridge P. The high-voltage power supply unit 53 converts low-voltage power supplied from the power supply unit 51 into high-voltage power, and supplies a bias voltage to the cartridge P, the belt unit 12, and the like. The left side plate 41 supports a rail (supporting portion) 54b that movably supports the sheet cassette 19 on the side of (inside) the sheet cassette 19 on the third side surface S3.

  The bottom plate 42 supports the belt unit 12, and the scanner stay 43 supports the scanner unit 11.

  In the frame structure, a portion overlapping with the image forming portion in the Z direction is defined as portion A, and a portion overlapping with the sheet cassette 19 is defined as portion B. In the frame structure of the present embodiment, the right side plate 40a is disposed in portion A, and The paper feed unit frame 40b is disposed in the portion. Then, in the X direction, the positions of the second side surfaces S2a and S2b of the sheet feeding unit frame 40b are arranged at positions different from the first side surface S1 of the right side plate 40a. According to this configuration, the width in the X direction of the space sandwiched between the first frame F1 (the right side plate 40a and the sheet feeding unit frame 40b) and the second frame F2 (the left side plate 41) is different between the portion A and the portion B. You can do so. Further, the second side surface S2a and the second side surface S2b are arranged at different positions in the X direction. According to this configuration, the width in the X direction of the space between the first frame F1 (the right side plate 40a and the sheet feeding unit frame 40b) and the second frame F2 (the left side plate 41) is made different even in the B portion. be able to.

  In this manner, by configuring the first frame F1 with a plurality of members (the right side plate 40a and the sheet feeding unit frame 40b), the width of the member disposed between the first frame F1 and the second frame F2 and the first The first side surface S1 and the second side surfaces S2a and S2b can be arranged at appropriate positions according to the width of the member supported by the frame F1. Therefore, the respective members are arranged so that useless space is unlikely to be generated, and it is possible to suppress the volume of the entire image forming apparatus 100 from increasing more than necessary.

  A comparison with the comparative example will be described. 7A is a diagram of the frame structure of Comparative Example 1 and the members supported by the frame structure viewed from the front side, and FIG. 7B is a diagram of the frame structure of Comparative Example 2 and the members supported by the frame structure viewed from the front side. is there. FIG. 8 is a view of the frame structure of Comparative Example 1 and members supported by the frame structure, as viewed from above.

  In Comparative Examples 1 and 2, the first frame F1 has one right side plate 40, and the right side plate 40 has one first side surface S1. In the configurations of Comparative Examples 1 and 2, the distance between the first side surface S1 of the right side plate 40 and the third side surface S3 of the left side plate 41 is determined by the width in the X direction of the portion A where the tray 35 is arranged. In Comparative Example 1, since the width of the power supply unit 51 in the X direction is large, the width of the image forming apparatus in the X direction may be increased because the power supply unit 51 protrudes in the X direction.

  In Comparative Example 2, for example, even if the width of the sheet feeding drive unit 50 in the X direction can be reduced, the distance between the first side surface S1 and the third side surface S3 is determined by the width of the portion A in the X direction. For this reason, a gap C is opened between the first side surface S1 and the sheet feeding drive unit 50, and it is difficult to reduce the size of the entire apparatus.

  Also, as in Comparative Example 1 shown in FIG. 8, when the width of the sheet cassette 19 and the sheet feeding drive unit 50 in the X direction are different, a gap is provided between the sheet cassette 19 and the first side surface S1. May be created.

  On the other hand, in the present embodiment, since the first frame F1 is configured by the right side plate 40a and the sheet feeding unit frame 40b, the second side surfaces S2a and S2b are arranged at positions different from the position of the first side surface S1. In particular, the second side surface S2a is arranged on the inner side of the first side surface S1 (on the side of the sheet cassette 19), and a portion of the power supply unit 51 where a relatively large component such as a transformer is arranged faces the second side surface S2a. The protrusion in the X direction of the power supply unit 51 is suppressed by arranging the power supply unit 51 at the position where the power supply unit 51 is located. In addition, the second side surface S2b is disposed outside the first side surface S1 (opposite to the sheet feeding cassette 19), and the sheet feeding driving unit 50 is disposed at a position facing the second side surface S2b. The generation of an unnecessary gap between the side surface S2a and the sheet cassette 19 is suppressed. Therefore, in the frame structure of the present embodiment, generation of unnecessary gaps can be suppressed, and the space in the apparatus can be effectively used. Note that at least a part (S2a and / or S2b) of the second side surface of the sheet feeding unit frame 40b is different from the first side surface S1 in the X direction (a position closer to or farther from the third side surface S3 than the first side surface). ), The above-described effect can be obtained.

  In the present embodiment, the left side plate 41 is a single member, and the third side surface of the left side plate 41 is used as a positioning reference for the bottom plate 42, the scanner stay 11, the cartridge P, the belt unit 12, and the paper feed unit 18. . Therefore, each member can be positioned with a certain accuracy. In particular, it is possible to reduce the influence on the positioning accuracy in the X direction due to the configuration in which the first frame F1 is divided by the right side plate 40a and the sheet feeding unit frame 40b.

  In Comparative Examples 1 and 2, as shown in the partial perspective view of the frame structure in FIG. 10, a member 70 having a shaft 70a, a guide 70b for a paper feed cassette, and the like was mounted on the right side plate 40. However, in the present embodiment, since the paper feeding unit frame 40b is made of resin, as shown in a partial perspective view of the frame structure of the image forming apparatus in FIG. The guide 56 and the guide 54 are formed integrally with the paper feed unit frame 40b. A wall portion W functioning as a fire protection enclosure is formed integrally with the sheet feeding portion frame 40b. As a result, the number of parts can be reduced, and the cost for assembling can be reduced.

<Second embodiment>
Next, a second embodiment will be described. In the present embodiment, the main configuration of the image forming apparatus is the same as that of the first embodiment except that a part of the frame structure and the like are different from that of the first embodiment, and the same parts as those of the first embodiment are the same. And the description is omitted. FIG. 11 is a view of the frame structure of the present embodiment and members supported by the frame structure as viewed from the front side. In the present embodiment, the first frame F1 is configured by the right side plate 40a including the first side surface S1 and the first sheet feeding unit frame 40b including the second side surface S2. In addition, the second frame F2 is configured by the left side plate 41a having the third side surface S3 and the second sheet feeding portion frame 41b having the fourth side surface S4. The right side plate 40a and the left side plate 41a are metal members, and the first paper supply unit frame 40b and the second paper supply unit frame 41b are resin members.

  A power supply unit 55 is disposed outside the third side surface S3 and the fourth side surface S4 (the side opposite to the cartridge P and the sheet cassette 19). The power supply unit 55 is an integrated power supply unit having the functions of the power supply unit (low-voltage power supply unit) 51 and the high-voltage power supply unit 53 of the first embodiment. In addition, the fourth side surface S4 is disposed inside (the sheet cassette 19 side) the third side surface S4, and a relatively large component such as a transformer of the power supply unit 55 is disposed at a position facing the fourth side surface S4. doing. Thus, the protrusion of the power supply unit 55 can be suppressed.

  According to the present embodiment, the same effects as those of the first embodiment can be obtained. That is, generation of unnecessary gaps can be suppressed, and the space in the apparatus can be effectively used.

  In addition, at least a part (S2a and / or S2b) of the second side is disposed at a position different from the first side S1 in the X direction, and at least a part (S4a and / or S4b) of the fourth side is in the X direction. The above-described effect can be obtained if it is arranged at a position different from the third side surface S3.

Reference Signs List 1 photosensitive drum 11 scanner stay 18 paper feed unit 19 paper feed cassette 23 fixing device 31 door 35 tray 40a right side plate 40b paper feed unit frame (first paper feed unit frame)
41 left side plate 41a left side plate 41b second paper feed unit frame 42 bottom plate 50 paper feed drive unit 51 power supply unit (low voltage power supply unit)
53 High-voltage power supply unit 55 Power supply unit F1 First frame F2 Second frame S1 First side S2a, S2b Second side S3 Third side S4 Fourth side

Claims (17)

An image forming unit including a rotatable image carrier, and transferring a toner image formed on the image carrier to a recording medium,
A loading unit that is detachable from the apparatus main body and that loads a recording medium to be conveyed to the image forming unit;
A first frame and a second frame that are arranged in the direction of the rotation axis of the image carrier and that face each other across the image forming unit and the stacking unit;
In the image forming apparatus having the loading unit below the image forming unit,
The first frame includes: a first member having a first side facing the image forming unit; and a second member fixed to the first member and having a second side facing the loading unit.
The second frame includes a third side facing the image forming unit and the loading unit,
The image forming apparatus according to claim 1, wherein at least a part of the second side surface is arranged at a position different from the first side surface in a rotation axis direction of the image carrier.   2. The apparatus according to claim 1, wherein at least a part of the second side surface is a portion arranged at a position closer to the third side surface than the first side surface in a rotation axis direction of the image carrier. 3. Image forming device.   3. The image forming apparatus according to claim 1, wherein at least a part of the second side surface is a portion arranged at a position farther from the third side surface than the first side surface in a rotation axis direction of the image carrier. The image forming apparatus as described in the above.   There are two stay members disposed between the first member and the second frame of the first frame, and the first member and the second frame are respectively fixed to the two stay members. The image forming apparatus according to claim 1, wherein:   In the rotation axis direction of the image carrier, the first member and the second frame abut against the two stay members, respectively, so that the distance between the first member and the second frame is determined. The image forming apparatus according to claim 4, wherein:   The second member supports a power supply unit for supplying power to the apparatus, and the power supply unit is disposed on the opposite side of the loading unit with respect to the rotation axis direction of the image carrier, with the second side surface interposed therebetween. The image forming apparatus according to claim 1, wherein:   The second member includes a wall portion protruding from the second side surface in the rotation axis direction of the image carrier, and the wall portion is disposed around the power supply unit when viewed in the rotation axis direction of the image carrier. The image forming apparatus according to claim 6, wherein:   The second member includes a support unit that supports the loading unit, and the support unit is disposed closer to the loading unit than the second side surface in the rotation axis direction of the image carrier. The image forming apparatus according to claim 1.   The second member supports a transport member drive unit that drives a transport member that transports a recording medium loaded on the loading unit, and the transport member drive unit is configured to move the second member with respect to a rotation axis direction of the image carrier. The image forming apparatus according to claim 1, wherein the image forming apparatus is disposed closer to the loading unit than a side surface.   The image forming apparatus according to claim 1, wherein the first member supports an image carrier driving unit that drives the image carrier.   The first member includes a hole that penetrates the first side surface, and the second member includes a protrusion inserted into the hole, and the protrusion abuts against an inner peripheral surface of the hole, so that the protrusion in the vertical direction is provided. The image forming apparatus according to claim 1, wherein a position of the second member with respect to the first member is determined.   A supporting member that supports the image carrier and is movable between a position inside the apparatus main body and a position outside the apparatus main body. When the moving member is at a position inside the apparatus main body, the moving member is The image forming apparatus according to any one of claims 1 to 11, wherein the image forming apparatus is disposed between the first member and the second frame at a position facing the first side surface.   The image forming apparatus according to claim 1, wherein the first member and the second frame are metal members, and the second member is a resin member.   The image forming apparatus according to claim 13, wherein the second member is a member made of a flame-retardant resin. An image forming unit including an image carrier, and transferring a toner image formed on the image carrier to a recording medium,
A loading unit for loading a recording medium to be transported to the image forming unit,
A first frame and a second frame that are arranged in the direction of the rotation axis of the image carrier and that face each other across the image forming unit and the stacking unit;
In the image forming apparatus having the loading unit below the image forming unit,
The first frame includes: a first member having a first side facing the image forming unit; and a second member fixed to the first member and having a second side facing the loading unit.
The second frame includes a third member having a third side facing the image forming unit, and a fourth member fixed to the third member and having a fourth side facing the loading unit,
At least a part of the second side surface is arranged at a position different from the first side surface, and at least a part of the fourth side surface is arranged at a position different from the third side surface in the rotation axis direction of the image carrier. An image forming apparatus comprising:   A moving member that supports the image carrier and moves the image carrier to a position inside the apparatus main body and a position outside the apparatus main body, and when the image carrier is at a position inside the apparatus main body, The image forming apparatus according to claim 15, wherein the moving member is disposed between the first member and the third member at a position facing the first side surface and the third side surface. 17.   17. The image forming apparatus according to claim 15, wherein the first member and the third member are metal members, and the second member and the fourth member are resin members.

Images