JP5961140B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  In general, an electrophotographic image forming apparatus such as a laser printer is provided with a toner container in which toner as a developer is accommodated, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-133830. The toner container is configured to be detachable from the image forming apparatus main body.

  The toner container has a toner supply port for supplying the toner in the container to a developing unit provided in the main body of the image forming apparatus. A shaft-shaped conveying screw for conveying the toner to the toner supply port is provided in the toner container. The image forming apparatus main body is provided with a motor as a drive source for the conveying screw.

  One end of the conveying screw is rotatably supported by a bearing formed in the toner container. On the other hand, the other end of the conveying screw is supported by a container side joint for transmitting the driving force from the motor to the conveying screw.

  The container side joint portion is formed so as to protrude outward from the toner container, and a triangular prism-shaped protrusion is formed at an end of the container side joint portion on the protruding side. The image forming apparatus main body is provided with a main body side joint portion having a triangular prism-shaped concave portion. When the toner container is mounted on the main body of the image forming apparatus, the protrusions of the container side joint portion are fitted into the recesses of the main body side joint portion so that both the joint portions are connected so as to transmit power. The main body side joint portion is rotatably supported by a shaft member provided in the main body of the image forming apparatus, and is connected to the motor via a gear mechanism.

JP 2009-168856 A

  However, in the image forming apparatus disclosed in Patent Document 1, the positional accuracy of the container side joint portion with respect to the main body side joint portion is, for example, the assembly accuracy (position accuracy) of the main body side joint portion with respect to the main body of the image forming apparatus or the toner container. It is influenced by many factors such as molding accuracy.

  For this reason, there exists a problem that it is difficult to ensure sufficiently the positional accuracy of the container side joint part with respect to the main body side joint part. As a result, there is a problem that the rotational accuracy of the conveying screw (rotating member) decreases due to, for example, the axial centers of both joint portions being shifted.

  The present invention has been made in view of the above points, and an object of the present invention is to provide assembly accuracy and molding of each component in an image forming apparatus including a main body portion on which a toner container is detachably mounted. The object is to sufficiently secure the positional accuracy of the container side joint portion with respect to the main body side joint portion without being influenced by the accuracy.

  The image forming apparatus according to the present invention includes a main body portion on which a toner container is detachably mounted.

The toner container is provided with a housing that accommodates toner, a rotating member that is provided in the housing and is rotatably supported by the housing, and protrudes outside the housing. A container-side joint portion integrally connected to the rotating member, the main body portion including a driving source that generates a driving force for driving the rotating member, and the toner container including the main body. in a state of being mounted on part is connected to the container side joint portion has a body-side joint portion to propagate to the container side joint portion a driving force from the drive source, the container side joint portion, the The container is disposed at a corner of a lower end portion of the opposing wall, spaced from a container-side coupling member provided at a central portion of the opposing wall facing a side wall on which a grip portion of the housing is formed. Side joint is triangular prism And a cylindrical positioning hole formed coaxially with the rotation axis of the container-side joint portion at the distal end surface of the joint projection portion, and the body-side joint portion has a triangular prism shape. Including a joint recess, and a cylindrical or cylindrical pin portion that protrudes from the bottom wall surface of the joint recess and is coaxial with the rotational axis of the body-side joint portion, and the container-side joint portion and the body-side joint portion are The joint concave portion and the joint protrusion are coupled so as to be able to transmit power, and the container side joint portion is positioned with respect to the main body side joint portion by fitting the pin portion and the positioning hole. is configured, fitting accuracy between the pin portion and the positioning hole is fitted accuracy between the joint recess and the joint protruding portion It is those also high.

  According to this configuration, when the toner container is attached to the main body portion of the image forming apparatus, the container side joint portion is connected to the main body side joint portion provided in the main body portion. As a result, the driving force of the motor is transmitted to the rotating member via both joint portions.

  Here, both the joint parts are configured to position the container side joint part with respect to the main body side joint part by fitting the pin part and the hole. Therefore, the positional accuracy of the container side joint portion relative to the main body side joint portion can be sufficiently ensured without being affected by the assembly accuracy and molding accuracy of each component. As a result, the rotation accuracy of the rotating member can be improved.

  In addition, according to the above configuration, the cylindrical hole formed in the container side joint portion is fitted into the columnar or cylindrical pin portion formed in the main body side joint portion, so that the container side joint with respect to the main body side joint portion is The parts are positioned so that the rotational axes of the joints coincide. Therefore, the rotation accuracy of the rotating member can be improved.

  The rotating member is preferably a conveying screw having a rotating shaft portion that is rotatably supported with respect to the casing, and a spiral blade portion formed on an outer peripheral surface of the rotating shaft portion.

  According to this configuration, it is possible to improve the rotation accuracy of the conveying screw that is a rotating member. As a result, unevenness in the rotation speed of the conveying screw can be eliminated, and the toner conveying amount per unit time by the conveying screw can be maintained constant.

  According to the present invention, the rotational accuracy of the rotating member supported by the toner container can be improved without being affected by the assembly accuracy and molding accuracy of each component.

FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to the present embodiment. FIG. 2 is a plan view showing the inside of the toner container. FIG. 3 is an exploded perspective view showing the configuration of the toner container. 4 is a view taken in the direction of the arrow IV in FIG. FIG. 5 is a cross-sectional view taken along the rotation axis of both joint portions, showing a connection structure between the container side joint portion and the main body side joint portion. FIG. 6 is an enlarged perspective view showing the container side joint portion. FIG. 7 is a perspective view showing the container holder. FIG. 8 is a view of the container holder as seen from the longitudinal direction of the base portion. FIG. 9 is an enlarged perspective view showing the main body side joint portion.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

<Laser printer>
FIG. 1 is a cross-sectional view showing a schematic configuration of a laser printer 1 as an image forming apparatus in the present embodiment.

  As shown in FIG. 1, the laser printer 1 includes an apparatus main body 2 as a main body of the image forming apparatus, and a toner container 21 detachably attached to the apparatus main body 2.

  The apparatus main body 2 includes a container holder 70 (see FIGS. 7 and 8), a manual paper feed unit 6, a cassette paper feed unit 7, an image forming unit 8, a fixing unit 9, and a paper discharge unit 10. doing. Thus, the laser printer 1 is configured to form an image on a sheet based on image data transmitted from a terminal (not shown) while conveying the sheet along the conveyance path L in the apparatus main body 2. ing.

  The container holder 70 is provided on the upper part of the apparatus main body 2. The container holder 70 is configured to detachably support the toner container 21 from below. Details of the container holder 70 will be described later.

  The manual paper feed unit 6 includes a manual feed tray 4 that can be opened and closed on one side of the apparatus main body 2, and a manual feed roller 5 that is rotatably provided inside the apparatus main body 2. ing.

  The cassette paper feeding unit 7 is provided at the bottom of the apparatus main body 2. The cassette paper feeding unit 7 separates the paper fed one by one, a paper feeding cassette 11 that stores a plurality of papers stacked on each other, a pick roller 12 that takes out the paper in the paper feeding cassette 11 one by one, and A feed roller 13 and a retard roller 14 that are fed to the transport path L.

  The image forming unit 8 is provided above the cassette paper feeding unit 7 in the apparatus main body 2. The image forming unit 8 includes a photosensitive drum 16 which is an image carrier rotatably provided in the apparatus main body 2, a charger 17 disposed around the photosensitive drum 16, a developing unit 18, a transfer roller 19, and a transfer roller 19. A cleaning unit 20 and a laser scanner unit (LSU) 30 which is an optical scanning device disposed above the photosensitive drum 16 are provided. Toner is supplied from the toner container 21 to the developing unit 18. Thus, the image forming unit 8 forms an image on the sheet supplied from the manual sheet feeding unit 6 or the cassette sheet feeding unit 7.

  The transport path L is provided with a pair of registration rollers 15 that supply the fed paper to the image forming unit 8 at a predetermined timing after temporarily waiting.

  The fixing unit 9 is disposed on the side of the image forming unit 8. The fixing unit 9 includes a fixing roller 22 and a pressure roller 23 that are pressed against each other and rotate. Thus, the fixing unit 9 is configured to fix the toner image transferred to the sheet by the image forming unit 8 on the sheet.

  The paper discharge unit 10 is provided above the fixing unit 9. The paper discharge unit 10 includes a paper discharge tray 3, a pair of paper discharge rollers 24 for conveying paper to the paper discharge tray 3, and a plurality of conveyance guide ribs 25 that guide the paper to the paper discharge roller pair 24. Yes. The paper discharge tray 3 is formed in a concave shape in the upper part of the apparatus main body 2.

  When the laser printer 1 receives the image data, the photosensitive drum 16 is rotationally driven in the image forming unit 8, and the charger 17 charges the surface of the photosensitive drum 16.

  Based on the image data, laser light is emitted from the laser scanner unit 30 to the photosensitive drum 16. An electrostatic latent image is formed on the surface of the photosensitive drum 16 by irradiation with laser light. On the other hand, toner is supplied from the toner container 21 to the developing unit 18. The electrostatic latent image formed on the photosensitive drum 16 is developed by the developing unit 18 to become a visible image as a toner image.

  Thereafter, the sheet is pressed against the surface of the photosensitive drum 16 by the transfer roller 19. As a result, the toner image on the photosensitive drum 16 is transferred to the paper. The sheet on which the toner image is transferred is heated and pressed by the fixing roller 22 and the pressure roller 23 in the fixing unit 9. As a result, the toner image is fixed on the paper.

<Toner container>
2 to 4 show the configuration of the toner container 21 in the present embodiment.

  For example, the toner container 21 is disposed above the image forming unit 8. As shown in FIGS. 2 and 3, the toner container 21 is mounted on the apparatus main body 2 and contains a casing 31 for storing toner, and a toner provided in the casing 31 for supplying toner to the apparatus main body 2. A supply port 38, an agitation mechanism 40 for agitating the toner inside the housing 31, and a screw part (conveyance screw) 50 for conveying the toner to the toner supply port 38 are provided.

  The housing 31 has a bottomed container main body 35 whose upper part is opened, and a lid 36 that closes an open part of the container main body 35. The container body 35 has a bottom portion 37 having an inner wall surface having an arcuate cross section.

  On the side wall 31 a of the housing 31, a grip portion 44 is formed so as to protrude to the outside of the housing 31 for the user to grip when the toner container 21 is attached to and detached from the apparatus main body 2. On the other hand, a pair of position restricting members 45 projecting to the outside of the housing 31 are formed on the side wall 31b facing the side wall 31a where the grip portion 44 is formed. The pair of position restricting members 45 are respectively inserted into a pair of through holes 75a formed in the position restricting plate 75 of the container holder 70 (see FIG. 7).

  As shown in FIG. 3, the stirring mechanism 40 is attached to the container main body 35. The stirring mechanism 40 includes a shaft 41 that is rotationally driven inside the housing 31 and a stirring sheet 42 attached to the shaft 41.

  The housing 31 extends along the shaft 41. One end of the shaft 41 is rotatably supported by the container body 35. On the other hand, the other end of the shaft 41 is connected to a container side coupling member 43 disposed outside the container body 35. The container side coupling member 43 is connected to the main body side coupling member 76 that protrudes from the drive case portion 72 (see FIG. 7) in a state where the toner container 21 is mounted on the container holder 70. Thus, the shaft 41 is rotationally driven by the driving force transmitted through the main body side coupling member 76 and the container side coupling member 43.

  The stirring sheet 42 is made of an elastic sheet member, and is formed of, for example, a plastic film. The stirring sheet 42 is formed in a rectangular shape, and a long side portion thereof is fixed to the shaft 41. The long side portion of the stirring sheet 42 that is not fixed to the shaft 41 moves while contacting the at least the inner wall surface of the bottom portion 37 of the housing 31 in the rotating state of the shaft 41. As a result, the toner in the housing 31 is stirred by the stirring sheet 42 that rotates together with the shaft 41.

  As shown in FIGS. 2 and 3, the conveying screw 50 extends in parallel with the shaft 41 and is driven to rotate inside the housing 31, and a spiral formed on the outer peripheral surface of the rotating shaft 51. Shaped blade portion 52. The conveying screw 50 is configured to convey toner in the axial direction of the conveying screw 50 by rotating.

  Then, when the shaft 41 of the stirring mechanism 40 is rotationally driven, the stirring sheet 42 rotates while contacting the inner wall surface of the bottom portion 37 of the container main body 35. As a result, the toner on the bottom portion 37 of the housing 31 is stirred up by the stirring sheet 42 and is lifted up toward the conveying screw 50. Next, the toner is conveyed to a toner supply port 38 formed at the bottom of the container main body 35 by a rotating conveyance screw 50. The toner reaching the toner supply port 38 is supplied to the developing unit 18 in the apparatus main body 2 of the laser printer 1.

  One end of the rotary shaft 51 of the conveying screw 50 is rotatably supported by a cylindrical bearing 54 (see FIG. 2). A cylindrical portion 51 a extending in the axial direction of the rotation shaft portion 51 is formed at the other end of the rotation shaft portion 51. The cylindrical portion 51 a of the rotation shaft portion 51 is externally fitted to one end portion of the container side joint member 55 for transmitting a driving force to the rotation shaft portion 51.

  As shown in FIG. 5, the container side joint member 55 has a joint claw portion 55a, and the claw portion 55a engages with an opening portion 51b formed on the side surface of the cylindrical portion 51a, whereby the container side The side joint member 55 is fixed to the cylindrical portion 51a. As a result, the rotation shaft portion 51 rotates integrally with the container side joint member 55.

  Here, the container main body 35 is formed with a cylindrical bearing portion 56 extending to the outside of the housing 31. The container side joint member 55 includes a cylindrical shaft portion 55b that is rotatably supported by the inner peripheral surface of the bearing portion 56, the joint claw portion 55a formed at one end of the shaft portion 55b, and the shaft portion 55b. And a triangular prism-shaped joint protrusion 55c formed on the other end side. A seal member 57 for preventing the toner from scattering outside the housing 31 is provided around the shaft portion 55 b in the housing 31.

  As shown in FIG. 6, the joint protrusion 55 c has a triangular prism shape that extends along the rotation axis of the container-side joint member 55. A cylindrical positioning hole 55d is formed on the distal end surface of the joint projection 55c. The positioning hole 55 d is formed coaxially with the shaft portion 55 b supported by the bearing portion 56. That is, the positioning hole 55 d is formed coaxially with the rotation axis of the container side joint member 55.

  On the other hand, a main body side joint member 77 for transmitting the driving force of the motor to the container side joint member 55 is attached to the container holder 70 to which the toner container 21 is mounted.

<Container holder>
As shown in FIGS. 7 and 8, the container holder 70 applies a driving force to the base portion 71 that supports the toner container 21 from below, the stirring mechanism 40 attached to the toner container 21, and the conveying screw 50. And a drive case portion 72.

  The base portion 71 is formed to have a substantially rectangular shape in plan view, and the longitudinal direction thereof coincides with the front-rear direction of the laser printer 1 (the direction perpendicular to the paper surface of FIG. 1). A pair of vertical plate portions 71 a extending in the longitudinal direction is formed on the upper surface portion of the base portion 71. The pair of vertical plate portions 71 a are disposed so as to face each other with a space therebetween in the width direction of the base portion 71. A horizontal rail plate portion 71b is formed on the opposing surface of each vertical plate portion 71a (only one rail plate portion 71b is shown in FIG. 7). Each rail plate portion 71b is configured to support the lower surface of the toner container 21 so as to be slidable in the longitudinal direction of the base portion.

  The drive case portion 72 is formed at one end portion in the longitudinal direction of the base portion 71. A position restricting plate 75 is erected between the drive case portion 72 and the one end portion of the rail plate portion 71 on the upper surface portion of the base portion 71. The position restricting plate 75 restricts the movement of the container 21 to one side in the longitudinal direction of the base portion by contacting the side surface 31 b of the toner container 21. The position restricting plate 75 is formed with two through holes 75a penetrating in the thickness direction, and the position restricting member 45 formed in the toner container 21 is inserted into each through hole 75a.

  The drive case portion 72 is perpendicular to the base portion 71 when viewed from the width direction of the base portion 71. The drive case portion 72 includes a case main body portion 73 integrally formed with the base portion 71 and a cover member 74 that covers the opposite side of the case main body portion 73 from the container mounting side. In the drive case portion 72, a motor (not shown) and a gear mechanism 80 (see FIG. 5) connected to the motor so as to be able to transmit power are accommodated.

  As shown in FIG. 5, the gear mechanism 80 transmits the driving force to the main body side coupling member 76 (not shown in FIG. 5) for transmitting the driving force to the shaft 41 of the stirring mechanism 40 and the conveying screw 50. Therefore, the main body side joint member 77 is connected. The main body side coupling member 76 and the main body side joint member 77 penetrate the drive case portion 72 and protrude from the container mounting side surface 72a. The main body side joint member 77 is a shaft-like member having a hole 77a that fits into the outer peripheral surface of the cylindrical support portion 74a. The cylindrical support portion 74a is integrally formed on the inner wall surface of the cover member 74, and the main body side joint member 77 is supported rotatably with respect to the cylindrical support portion 74a. On the outer peripheral surface of the main body side joint member 77, a gear portion 77f is formed over the entire circumference. The gear portion 77f is connected to a motor (not shown) via an idle gear 78.

  The main body side joint member 77 is urged to the outer side of the drive case portion 72 by a coil spring 80 inserted on the cylindrical support portion 74a. At one end of the main body side joint member 77, a bottomed joint concave portion 77b that opens to one side in the axial direction is formed.

  As shown in FIG. 9, the joint recess 77 b has a triangular prism shape, and is configured to be fitted to the joint protrusion 55 c of the container side joint member 55. A cylindrical pin portion 77c protrudes from the bottom wall portion of the joint recess 77b. The pin portion 77c is formed coaxially with the hole portion 77a fitted into the cylindrical support portion 74a. That is, the pin portion 77 c is formed coaxially with the rotation axis of the main body side joint member 77. The pin portion 77c is configured to be fitted into a positioning hole 55d formed in the joint projection portion 55c. The fitting accuracy between the pin portion 77c and the positioning hole 55d (for example, a gap fitting of 0.02 mm to 0.03 mm) is the fitting accuracy between the joint protrusion 55c and the joint recess 77b (eg, 0.1 mm to 0.00 mm). Higher than 2 mm gap fitting).

  When the toner container 21 is mounted on the container holder 70, first, the toner container 21 is placed on the rail plate portion 71b so that the side wall 31b faces the drive case portion 72 (see FIG. 7). Then, the placed toner container 21 is slid from the other side in the longitudinal direction of the base portion toward one side so that the side wall 31b abuts the position regulating plate 75. Then, the container side coupling member 43 provided in the toner container 21 is connected to the main body side coupling member 76 attached to the container holder 70, and the power from the motor is transmitted through the coupling members 43 and 76. It can be transmitted to the stirring mechanism 40 (shaft 41). Further, the joint protrusion 55 c of the container side joint member 55 provided in the toner container 21 is fitted in the joint recess 77 b of the main body side joint member 77 attached to the container holder 70. As a result, the container side joint member 55 is connected to the main body side joint member 77 so as to rotate integrally (power transmission is possible). At this time, the positioning holes 55d formed in the joint projection 55c are fitted into the pin portions 77c formed in the main body side joint member 77b of the main body side joint member 77. The positional accuracy of the container side joint member 55 with respect to the main body side joint member 77 can be sufficiently secured without being affected by the accuracy. As a result, the rotational accuracy of the conveying screw 50 connected to the container side joint member 55 can be improved.

  In the above embodiment, the positioning hole 55d formed in the container side joint member 55 is formed coaxially with the rotational axis of the joint member 55, and the pin portion 77c formed in the main body side joint member 77 is The joint member 77 is formed coaxially with the rotational axis.

  Therefore, when the positioning hole 55d formed in the container side joint member 55 is fitted into the pin portion 77c formed in the main body side joint member 77, the rotational axes of both the joint members 55 and 77 coincide. It becomes. Therefore, the rotation accuracy of the conveying screw 50 can be improved as much as possible. As a result, the unevenness of the rotation speed of the conveying screw 50 can be eliminated, and the amount of toner conveyed by the conveying screw 50 per unit time can be kept constant.

  <Other embodiments>

  Moreover, in the said embodiment, although the container side joint member 55 is comprised separately from the rotating shaft part 51 of the conveyance screw 50, it is not restricted to this, It integrally molds with respect to the rotating shaft part 51. You may make it do.

  Moreover, in the said embodiment, although the pin part 77c is formed in the column shape, it is not restricted to this, For example, you may form in the cylindrical shape.

  In the above-described embodiment, the laser printer 1 has been described as an example of the image forming apparatus. However, the image forming apparatus according to the present invention is not limited to this, and may be another type such as a copying machine, a scanner device, or a multifunction peripheral. An image forming apparatus may be used.

<Reference form>
In the above-described embodiment, the positioning hole 55d is formed in the container side joint member 55 and the pin portion 77c is formed in the main body side joint member 77. And a positioning hole may be formed in the main body side joint member 77. In this case, the positioning hole is preferably formed coaxially with the rotation axis of the main body side joint member 77, and the pin portion is preferably formed coaxially with the rotation axis of the container side joint member 55. .

  In the above embodiment, the container side joint member 55 is positioned with respect to the main body side joint member 77 by fitting the pin portion 77c and the positioning hole 55d. You may make it position the container side coupling member 43 with respect to the main body side coupling member 76 by a positioning hole and fitting.

  As described above, the present invention is useful for an image forming apparatus, and particularly useful for an image forming apparatus including a main body portion to which a toner container is detachably attached.

1 Laser printer (image forming device)
2 Main unit (main unit)
21 Toner container (toner container)
31 Housing 50 Conveying screw (rotating member)
51 Rotating shaft portion 52 Blade portion 55 Container side joint member (container side joint portion)
55d Positioning hole (hole)
77 Body side joint member (Body side joint part)
77c Pin part

Claims (2)

An image forming apparatus including a main body portion on which a toner container is detachably mounted,
The toner container includes a housing for storing toner, a rotating member that is provided in the housing and is rotatably supported by the housing, and is provided to protrude outside the housing. A container-side joint connected to the member so as to rotate together,
The main body is coupled to the container side joint with the driving source generating a driving force for driving the rotating member and the toner container mounted on the main body, and is driven from the driving source. A main body side joint portion for transmitting force to the container side joint portion,
The container side joint portion is separated from a container side coupling member for driving a stirring mechanism provided at a central portion of the opposing wall facing the side wall on which the grip portion of the housing is formed. It is arranged at the corner of the lower end,
The container-side joint portion includes a triangular protrusion-shaped joint projection, and a cylindrical positioning hole formed coaxially with the rotation axis of the container-side joint portion on the distal end surface of the joint projection,
The body-side joint part includes a joint recess which forms a triangular pillar shape, a columnar or cylindrical pin portion forming the rotation axis coaxial with the main body side joint portion with projecting from the bottom wall surface of the joint recess ,
The container side joint portion and the main body side joint portion are connected so as to be able to transmit power by fitting the joint concave portion and the joint projection portion, and the main body side joint by fitting the pin portion and the positioning hole. Configured to position the container side joint part with respect to the part ,
The image forming apparatus, wherein a fitting accuracy between the pin portion and the positioning hole is higher than a fitting accuracy between the joint concave portion and the joint projection portion . The image forming apparatus according to claim 1.
The image forming apparatus, wherein the rotating member is a conveying screw having a rotating shaft portion rotatably supported with respect to the housing and a spiral blade portion formed on an outer peripheral surface of the rotating shaft portion.

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