Image formation apparatus

Abstract

To provide an image formation apparatus that can be downsized.SOLUTION: An image formation apparatus includes: an image carrier; a transfer member; a fixing unit; a driving source; an ejection member for ejecting to the outside a sheet on which a toner image has been fixed by the fixing unit; an ejection tray where sheets ejected by the ejection member are stacked; a regulation member which regulates a position of an end of a sheet stacked on the ejection tray, in a sheet width direction being orthogonal to a sheet ejection direction of the ejection member, and which extends to an upward side in a vertical direction relative to the ejection tray; and a support frame for supporting the driving source. The driving source is arranged partly overlapped with the regulation member, when viewed in the first direction.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Conventionally, a printer has been proposed that has a process cartridge having a photosensitive drum, and left and right side plates that detachably support the process cartridge (see Patent Document 1). A motor is disposed between the left and right side plates, and the driving force of the motor is transmitted to the main body coupling via a gear train. The process cartridge has a drum coupling that rotates together with the photosensitive drum, and the driving force is transmitted from the motor to the photosensitive drum by engaging the drum coupling with the main body coupling. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-45375 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for miniaturization in printers capable of printing on sheets such as that disclosed in Patent Document 1. An object of the present invention is to provide an image forming apparatus that can be miniaturized. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, a typical configuration of the invention related to the present application is an image forming apparatus comprising an image carrier supported rotatably around a rotation axis extending in a first direction and carrying a toner image, a transfer member that transfers the toner image to a sheet, a fixing unit that fixes the toner image transferred by the transfer member to the sheet, a drive source capable of driving the fixing unit, an ejection member for ejecting the sheet on which the toner image is fixed by the fixing unit to the outside, an ejection tray on which the sheets ejected by the ejection member are stacked, a regulating member for regulating the position of an end of the sheets stacked on the ejection tray in a sheet width direction that intersects with the sheet ejection direction of the ejection roller, the regulating member being configured to extend upward in a vertical direction relative to the ejection tray, and a support frame that supports the drive source, wherein the drive source is arranged so that at least a portion of it overlaps with the regulating member when viewed in the first direction. Effect of the Invention

[0006] According to the present invention, it is possible to provide an image forming apparatus that can be made compact. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing an image forming apparatus according to a first embodiment. [Diagram 2] FIG. 1 is a perspective view showing an image forming apparatus according to a first embodiment. [Diagram 3] FIG. 2 is a cross-sectional view showing the image forming apparatus according to the first embodiment, illustrating the positional relationship of motor arrangement. [Figure 4] FIG. 2 is a perspective view illustrating a motor mounting method according to the first embodiment. [Diagram 5] FIG. 2 is a perspective view illustrating a drive gear train according to the first embodiment. [Figure 6] FIG. 2 is a diagram illustrating a positional relationship of a motor according to the first embodiment. [Figure 7] FIG. 13 is a perspective view illustrating a motor mounting method according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments may be changed as appropriate depending on the configuration and various conditions of the device to which the present invention is applied. Therefore, unless otherwise specified, it is not intended to limit the scope of the present invention to only those.

[0009] <First embodiment> [Overall structure] An image forming apparatus according to the first embodiment will be described with reference to Figures 1 and 2. Figure 1 is a schematic cross-sectional view of an electrophotographic image forming apparatus according to the first embodiment. Here, a monochrome image forming apparatus that is an electrophotographic laser beam printer is exemplified as the image forming apparatus.

[0010] As shown in Fig. 1, a cross-sectional view of the overall configuration of the image forming apparatus of this embodiment is shown. In the image forming apparatus 100, a laser scanner 11, a photosensitive drum 1, a developing roller 41, a heating member 28, a pressure roller 27, a feed cassette 21, a feed roller 22, etc. are installed in the apparatus body. The feed cassette 21, which is a storage cassette for storing sheets, is configured to be detachable from the image forming apparatus 100. The photosensitive drum 1 is an image carrier that carries a toner image.

[0011] The sheets S stored in a feed cassette 21 are fed by a feed roller 22 rotating counterclockwise in the figure, and are conveyed by transport rollers 23 and 24 to a nip portion between the photosensitive drum 1 and a transfer roller 25 which is a transfer member.

[0012] The photosensitive drum 1 is supported rotatably about a rotation axis extending in a first direction, and electrostatic latent images are sequentially formed on its outer circumferential surface by laser light L from a laser scanner 11, and then the electrostatic latent images are developed by a developing roller 41 to form toner images. Here, the first direction is a direction parallel to the Y1 direction in FIG. 2.

[0013] The toner image formed on the photosensitive drum 1 is transferred onto a sheet S sent to a nip portion between the photosensitive drum 1 and a transfer roller 25 .

[0014] Furthermore, the sheet S onto which the toner image has been transferred is sent to a nip portion between a heating member 28 and a pressure roller 27, where the toner image is fixed onto the sheet S by being heated and pressurized.

[0015] The sheet S on which the toner image has been fixed is discharged from the inside of the image forming apparatus 100 to the outside by a pair of discharge rollers 29 which are discharge members, and is stacked on a discharge tray 30.

[0016] The photosensitive drum 1 of the present embodiment is detachably mounted to the image forming apparatus 100 as a process cartridge P integral with a charging roller 43, a developing unit 40, and the like, which serve as process members acting on the photosensitive drum 1.

[0017] 2 is a perspective view of the image forming apparatus of this embodiment. An ejection tray 30 is provided on the upper surface of the image forming apparatus 100, and aligns and stacks the sheets ejected from the image forming apparatus 100. The ejection tray 30 is a slope that slopes down into the image forming apparatus body toward the pair of ejection rollers 29. In the sheet width direction that intersects with the sheet ejection direction, regulating surfaces 30a and 30b that are regulating members are provided on both ends of the ejection tray 30, and are walls that stand upright above the stacking surface. These regulating surfaces 30a and 30b regulate the sheets ejected onto the stacking surface from protruding from the ejection tray 30 in the width direction, and are provided on the upper surface of the apparatus body with a width slightly wider than the sheet width.

[0018] 3 to 6 are diagrams illustrating the arrangement of a motor 61, which is a driving source of this embodiment. The motor 61 has a rotor portion 61b that generates a driving force, and a pinion gear 61a fixed to an output shaft that rotates together with the rotor portion 61b.

[0019] Fig. 3 is a cross-sectional view of the image forming apparatus 100 of this embodiment. A motor 61, which is a drive source for driving the photosensitive drum 1 and the pressure roller 27, is provided inside a side plate 63 (see Fig. 4) constituting the housing of the image forming apparatus 100. Fig. 3 is a cross-sectional view of the state in which the regulating surface 30a is viewed from the discharge tray 30 side in the Y1-Y2 direction, which is the sheet width direction that intersects with the direction in which the sheet is discharged by the discharge roller pair 29 in Fig. 2.

[0020] The motor 61 is disposed so that a portion of the motor 61 overlaps with a regulating surface 30a provided on the paper discharge tray when the image forming apparatus 100 is projected in the Y1 direction in Fig. 2 (the direction of the cross-sectional view in Fig. 3). The motor 61 is disposed between the regulating surface 30a and the side plate 63 in the cross section (Fig. 6) as viewed in the X direction in Fig. 2.

[0021] 4 is a perspective view showing a method of mounting the motor 61 to the side plate 63 in the image forming apparatus 100 of this embodiment. As shown in the figure, the motor 61 has a pinion gear 61a, which penetrates a first opening 63a provided in the side plate 63, which is a support frame, and protrudes outside (to the exterior side) of the image forming apparatus 100 beyond the side plate 63. The motor 61 is fixed to the side plate 63 with a screw 62, which is a fixing member. The screw 62 penetrates a second opening 63b provided in the side plate 63 and engages with the motor 61.

[0022] FIG. 5 is a perspective view of a drive gear train that transmits drive from the motor 61 to the photosensitive drum 1 and the pressure roller 27 in the image forming apparatus 100 of this embodiment. As shown in the figure, the pinion gear 61a provided on the motor 61 is connected to a drum drive gear 64 for transmitting drive to the process cartridge P through a gear train 66. The pinion gear 61a is also connected to a pressure roller gear 65 for driving the pressure roller 27 provided in the fixing unit 26 through a gear train 66. The gear train 66 is disposed between the side plate 63 and the exterior member 100S facing the side plate 63. In this figure, the gear train that transmits drive to the discharge roller pair 29 and the feed roller 22 is omitted, but the drive is transmitted from the pinion gear 61a in the same manner. A rotor portion 61b that generates the drive force of the motor 61 is disposed between the regulating surface 30a and the side plate 63, and the pinion gear 61a fixed to the output shaft that rotates together with the rotor portion 61b is disposed between the side plate 63 and the exterior member 100S. This makes it possible to effectively utilize the space between the regulating surface 30a and the side plate 63, while having the pinion gear 61a protrude outside the side plate 63, thereby transmitting the drive to each driven member via the gear train 66 arranged outside the side plate 63. Therefore, it is not necessary to arrange the entire motor 61 outside the side plate 63, and it is possible to achieve a reduction in the size of the image forming apparatus 100.

[0023] 3, the motor 61 is disposed between the photosensitive drum 1 and the pressure roller 27, so that each can be driven with a small number of gears. This makes it possible to reduce the number of meshing gears between the photosensitive drum 1 and the pressure roller 27. As a result, it is possible to reduce fluctuations in rotation speed caused by the meshing gears of the photosensitive drum 1 and the pressure roller 27.

[0024] Furthermore, since the motor 61 does not compress the space around the developing unit 40 that contains the developer of the process cartridge P, it is possible to secure a large developer volume.

[0025] 6 is a cross-sectional view of the image forming apparatus 100 in the front-rear direction in this embodiment, showing the position of the motor 61. The motor 61 is disposed above the feeding cassette 21, and is disposed so that a part of the motor 61 overlaps a part of the feeding tray 21 when the image forming apparatus 100 is projected in the up-down direction (Z direction). In this embodiment, the guided portion 21a of the feeding tray 21 and the guide 200 (provided in the image forming apparatus 100) that guides the guided portion 21a overlap with the motor 61 when projected in the up-down direction (Z direction). As a result, the position of the motor 61 does not interfere with the feeding tray 21 in the Y direction, so that it is possible to achieve a reduction in the size of the image forming apparatus 100 in the Y direction.

[0026] FIG. 7 is a diagram for explaining a method of attaching the motor 61 and the gear train in the modified example. FIG. 7(a) shows a state in which the drive unit 60 is removed from the side plate 63. As shown in FIG. 7(a), the motor 61, the drum drive gear 64 which couples with the process cartridge P and transmits the drive force, and the gear train which drives the pressure roller 27 are sandwiched by sheet metal to form a unit, and can be assembled to the side plate 63 with screws (not shown). Although not shown in the modified example, the drive unit 60 may be a unit including the drive gears and actuators of the feed roller 22 and the pair of discharge rollers 29. The motor 61 in this embodiment is also provided with a pinion gear (not shown) which faces the outside of the image forming apparatus 100. The drive unit 60 is assembled to the side plate 63 in the direction of the arrow A in the figure. FIG. 7(b) shows a state in which the drive unit 60 is attached to the side plate 63, and the motor 61 is installed penetrating the side plate 63 and is disposed between the side plate 63 and the paper discharge tray regulating surface 30a. Further, the motor 61 after being arranged is arranged so that a part of the motor 61 overlaps with the regulating surface 30a provided on the paper discharge tray when the image forming apparatus 100 is projected in the left-right direction.

[0027] This allows the motor 61 to be efficiently arranged in the space inside the device body, which can contribute to making the device body 100 more compact.

[0028] In this embodiment, the process cartridge P and the fixing unit 26 are arranged side by side in the horizontal direction. However, the fixing unit 26 may be arranged above the process cartridge P.

[0029] The present invention can also be applied to an image forming apparatus that employs a plurality of photosensitive drums and an intermediate transfer belt unit. In this case, the intermediate transfer belt of the intermediate transfer belt unit serves as an image carrier, and the secondary transfer roller serves as a transfer member.

[0030] The disclosure of the present embodiment also includes the following configuration examples and method examples.

[0031] (Configuration 1) an image carrier that is rotatably supported around a rotation axis extending in a first direction and that carries a toner image; A transfer member for transferring the toner image onto a sheet; a fixing unit for fixing the toner image transferred by the transfer member onto a sheet; a drive source capable of driving the fixing unit; a discharge member for discharging the sheet on which the toner image has been fixed by the fixing unit to the outside; a discharge tray on which the sheets discharged by the discharge member are stacked; a regulating member for regulating a position of an end of the sheet stacked on the discharge tray in a sheet width direction intersecting with a sheet discharge direction of the discharge member, the regulating member being configured to extend upward in a vertical direction with respect to the discharge tray; a support frame supporting the drive source, The image forming apparatus, wherein the driving source is disposed so as to overlap at least a portion of the regulating member when viewed in the first direction.

[0032] (Configuration 2) 2. The image forming apparatus according to claim 1, wherein at least a portion of the driving source is located between the regulating member and the support frame in the first direction.

[0033] (Configuration 3) an exterior member that covers the support frame and constitutes an exterior of the image forming apparatus; the driving source includes a rotor portion that generates a driving force and a pinion gear that rotates together with the rotor portion, The image forming apparatus of configuration 1 or 2, characterized in that the rotor portion is disposed between the regulating member and the support frame in the first direction, and the pinion gear is disposed between the support frame and the exterior member.

[0034] (Configuration 4) The image forming apparatus according to any one of configurations 1 to 3, wherein the support frame supports a gear train between the support frame and the exterior member for drivably connecting the pinion gear and the fixing unit.

[0035] (Configuration 5) 5. The image forming apparatus according to claim 1, wherein the support frame includes a first opening for allowing the pinion gear to pass therethrough.

[0036] (Configuration 6) The image forming apparatus according to any one of configurations 1 to 5, wherein the support frame has a second opening for passing a fixing member for fixing the driving source to the support frame.

[0037] (Configuration 7) In the support frame, in the first direction, the rotor portion side is an inner side, and a pinion gear side protruding from the first opening side is an outer side, The image forming apparatus according to any one of configurations 1 to 6, wherein the fixing member is a screw that protrudes from the outside to the inside through the second opening and engages with the driving source. [Explanation of symbols]

[0038] 1 Photoconductor drum 26 Fixing unit 27 Pressure roller 30 Output Tray 30a Paper output tray wall 61 Driving source (motor) 61a Pinion gear

Claims

1. an image carrier that is rotatably supported around a rotation axis extending in a first direction and that carries a toner image; A transfer member for transferring the toner image onto a sheet; a fixing unit for fixing the toner image transferred by the transfer member onto a sheet; a drive source capable of driving the fixing unit; a discharge member for discharging the sheet on which the toner image has been fixed by the fixing unit to the outside; a discharge tray on which the sheets discharged by the discharge member are stacked; a regulating member for regulating a position of an end of the sheet stacked on the discharge tray in a sheet width direction intersecting with a sheet discharge direction of the discharge member, the regulating member being configured to extend upward in a vertical direction with respect to the discharge tray; a support frame supporting the drive source, The image forming apparatus according to claim 1, wherein the driving source is disposed so as to at least partially overlap the regulating member when viewed in the first direction.

2. 2 . The image forming apparatus according to claim 1 , wherein at least a portion of the driving source is located between the regulating member and the support frame in the first direction.

3. an exterior member that covers the support frame and constitutes an exterior of the image forming apparatus; the driving source includes a rotor portion that generates a driving force and a pinion gear that rotates together with the rotor portion, 3. The image forming apparatus according to claim 2, wherein the rotor portion is disposed between the regulating member and the support frame in the first direction, and the pinion gear is disposed between the support frame and the exterior member.

4. 4. The image forming apparatus according to claim 3, wherein the support frame supports a gear train between the support frame and the exterior member for drivably connecting the pinion gear and the fixing unit.

5. 5. The image forming apparatus according to claim 4, wherein the support frame is provided with a first opening for allowing the pinion gear to pass therethrough.

6. 6. The image forming apparatus according to claim 5, wherein the support frame is provided with a second opening for passing a fixing member for fixing the driving source to the support frame.

7. In the support frame, in the first direction, the rotor portion side is an inner side, and a pinion gear side protruding from the first opening side is an outer side, 7. The image forming apparatus according to claim 6, wherein the fixing member is a screw, which protrudes from the outside to the inside through the second opening and engages with the driving source.

8. the driving source is capable of driving the image carrier, 8. The image forming apparatus according to claim 1, wherein the support frame supports a drive gear for driving the image carrier.

9. 9. The image forming apparatus according to claim 8, wherein the image carrier is a photosensitive drum.

10. 10. The image forming apparatus according to claim 9, wherein the driving source is disposed between the fixing unit and the photoconductor drum in a horizontal direction intersecting with the first direction.

Images