JP6292106B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including an electrical substrate.

  The image forming apparatus includes an electrical board such as a control board or a power board for controlling an image forming operation. On the electrical board, a CPU, memory, and various electronic components are mounted. In order to block electromagnetic waves generated from the CPU, etc., or to prevent the CPU from malfunctioning due to high frequency noise, etc. The electrical board is accommodated in a shield box. Shield boxes are required to save space associated with downsizing image forming apparatuses and to improve shield performance.

  Patent Document 1 discloses an image forming apparatus in which a shield box is rotatably disposed outside a drive transmission mechanism of an image forming unit to save space. Further, in Patent Document 2, a connection portion protruding in a direction facing the bottom plate and the cover plate of the shield box is provided, and the electrical circuit board is sandwiched by this connection portion, thereby reducing the loop current path. A shield box with reduced unwanted radiation is disclosed. Further, Patent Document 3 discloses a shield box that accommodates an electrical board on which a recess into which a drive transmission mechanism of an image forming unit is inserted.

Japanese Patent Application Laid-Open No. 07-129061 JP 2005-294627 A JP 2007-95967 A

  However, the image forming apparatus described in Patent Document 1 requires a mechanism for rotating the shield box, which complicates the structure and increases the number of parts. Moreover, in the shield box described in Patent Document 2, it becomes difficult for heat to circulate in the shield box by forming the connection portion. When the lid of the shield box directly constitutes the outer surface of the image forming apparatus, the lid and the electrical board are electrically connected, so that static electricity may flow to the electrical board from the lid. Furthermore, in the shield box described in Patent Document 3, there is a possibility that the space between the grounding portions of the electrical board becomes long, or a structure that allows easy opening around the electrical board, resulting in insufficient shielding. There is.

  In view of the above circumstances, an object of the present invention is to provide an image forming apparatus capable of reducing the arrangement space of the electrical substrate and improving the shielding performance of the electrical substrate.

  In order to solve the above problems, an image forming apparatus of the present invention is provided so as to be conductive to a conductive housing that accommodates an image forming portion and a drive transmission mechanism of the image forming portion. An image forming apparatus comprising a conductive support plate and an electric board that controls an image forming operation of the image forming unit, wherein a part of the support plate is a bottom plate of a shield box that houses the electric board. It is characterized by forming.

  By adopting such a configuration, it is possible to save the space of the shield box and reduce the number of parts.

  In the image forming apparatus of the present invention, the shield box may have a lid, and the lid may be supported by at least one of the casing or the support plate so as to be conductive.

  By adopting such a configuration, since the electrical board is not directly electrically connected to the lid, it is possible to avoid a situation in which static electricity flows through the lid to the electrical board. Therefore, the lid can also be used as an exterior cover, and the structure can be simplified and the cost can be reduced.

  In the image forming apparatus of the present invention, the support plate is provided to protrude outward from the housing, and the inner space of the shield box has a shape in which a part of a rectangular parallelepiped is cut out by the support plate. It is good also as having.

  By adopting such a configuration, the internal space of the shield box does not have a simple rectangular parallelepiped shape, so that the cavity resonance phenomenon of the electromagnetic wave generated from the electrical substrate can be suppressed, and the amplification and leakage of the electromagnetic wave can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the leakage of the electromagnetic wave from an electrical equipment board | substrate can be prevented reliably, and an electrical equipment board | substrate can be arrange | positioned in a space-saving.

FIG. 3 is a perspective view showing a housing in which the image forming unit is accommodated in the image forming apparatus according to the embodiment of the present disclosure. In the image forming apparatus according to an embodiment of the present invention, it is a perspective view showing a front plate of a housing provided with a support plate. In the image forming apparatus according to an embodiment of the present invention, it is a perspective view showing a front plate of a housing provided with an electrical board and a support plate. 1 is a perspective view showing a front plate and an electrical board of a housing in an image forming apparatus according to an embodiment of the present invention. 1 is a perspective view showing a front plate and a cover plate of a housing in an image forming apparatus according to an embodiment of the present invention. 6A and 6B are diagrams schematically showing the structure of a shield box in an image forming apparatus according to an embodiment of the present invention, in which FIG. 6A is a cross-sectional view and FIG. 6B is a vertical cross-sectional view.

  Hereinafter, an image forming apparatus according to an embodiment of the present disclosure will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a housing in which an image forming unit is accommodated in an image forming apparatus according to an embodiment of the present invention. In the following description, the front side of the sheet in FIG. 1 is the front side (front side) of the image forming apparatus, and the horizontal direction is based on the direction of the image forming apparatus viewed from the front side.

  The image forming apparatus 1 includes a rectangular parallelepiped housing 2 in which an image forming unit is accommodated. The housing 2 includes a rectangular bottom plate 3, horizontally long rectangular front plates 4 and rear plates 5 arranged opposite to each other in the front-rear direction, and a partition plate that partitions a space between the front and rear plates 4, 5 in the vertical direction. 6. In the space between the front and rear plates 4, 5, an image forming unit (not shown) is accommodated on the right side of the partition plate 6, and a sheet feeding / conveying unit (not shown) is accommodated on the left side of the partition plate 6. In the image forming unit, image forming units that form an image by electrophotography using four color toners are arranged side by side. Each image forming unit includes elements such as a photosensitive drum, a charging device, a developing device, and a cleaning device, and each element is driven by a drive transmission mechanism 10. The drive transmission mechanism 10 includes a motor 11 and a gear train (not shown) that transmits the driving force of the motor 11 to each element of each image forming unit.

  Further, the housing 2 includes a front plate 4, a support plate 40 that supports the drive transmission mechanism 10, a main body substrate 70 (electrical board) that controls driving of the image forming unit and the paper feeding / conveying unit, and an image forming unit. And a power supply board 75 that supplies power to the paper feed conveyance unit, and a cover body 80 that covers the main body board 70 and the power supply board 75 are supported, and the front plate 4, the support plate 40, and the cover body 80, A shield box 100 in which main body substrate 70 and power supply substrate 75 are accommodated is formed.

  The front plate 4 and the support plate 40 of the housing 2 will be described with reference to FIG. FIG. 2 is a perspective view showing a front plate of a housing on which a support plate is mounted.

  The front plate 4 of the housing 2 is formed with two screw holes 21 arranged in the left-right direction at the upper left corner, and a rectangular opening 22 at the lower right corner.

  The front plate 4 has an upper outer peripheral portion 24, a lower outer peripheral portion 25, a left outer peripheral portion 26, and a right outer peripheral portion 27 that are bent forward from the outer peripheral edges of the upper, lower, left, and right sides. The left outer peripheral portion 26 is formed with five screw holes 31 with a predetermined interval in the vertical direction and a plurality of openings and notches. Further, the left outer peripheral portion 26 is formed with three protruding pieces 32 bent inward with a predetermined interval in the vertical direction. Each projecting piece 32 has a screw hole 33 formed therein. Further, a lower edge portion 35 bent upward is formed on the lower outer peripheral portion 25 on the left side of the opening 22 formed in the front plate 4. An engaged portion 36 is formed in the lower edge portion 35 with a predetermined interval in the left-right direction.

  The support plate 40 is disposed above the opening 22 on the right side of the center of the front plate 4 of the housing 2. The support plate 40 is made of a conductive material such as a sheet metal material, and is a horizontally long, substantially rectangular bottom 41, an upper outer peripheral portion 42 and a lower outer peripheral portion 43 that are bent backward from the upper, lower, left, and right outer peripheral edges of the bottom 41. A left outer peripheral portion 44, a right outer peripheral portion 45, and an upper edge portion 47, a lower edge portion 48, a left edge portion 49, and a right edge portion (not shown) bent outward from the front end edge of each outer peripheral portion. . In the drive transmission mechanism 10, the motor 11 is disposed on the outer surface of the bottom 41, and the gear train is disposed in a flat space surrounded by the bottom 41 and the outer peripheral portions 42, 43, 44, 45.

  A motor mounting plate 50 to which the motor 11 is mounted is supported on the outer surface of the bottom 41 near the center. The motor attachment plate 50 is formed of a conductive material, and has a rectangular flat plate portion 51 to which the motor 11 is attached, and a rising portion 52 that bends forward from the left side of the flat plate portion 51 and extends beyond the height of the motor 11. , And an edge portion 53 bent leftward from the tip of the rising portion 52. Two screw holes 54 are formed in the edge portion 53 at a predetermined interval in the vertical direction. The motor mounting plate 50 has a flat plate portion 51 fixed by a screw near the center of the bottom portion 41 and is connected to the support plate 40 so as to be conductive.

  A flat portion 60 is formed on the outer surface of the bottom portion 41 on the left side of the motor mounting plate 50. At the right end portion of the flat portion 60, there are formed three projecting pieces 61 cut and raised from the flat portion 60 with a predetermined interval in the vertical direction. Further, a protruding piece 61 cut and raised from the flat portion 60 is also formed at the left corner of the flat portion 60. Each projecting piece 61 is formed with a screw hole 62.

  Further, screw holes 65 are formed at predetermined positions on the upper edge portion 47, the lower edge portion 48, the left edge portion 49, and the right edge portion, respectively. 2 is fastened to the front plate 4 with screws and is supported on the front plate 4 so as to be conductive. That is, the support plate 40 is supported so as to protrude outward from the front plate 4 by the height of the upper edge portion 47, the lower edge portion 48, the left edge portion 49, and the right edge portion.

  Next, the main body substrate 70 and the power supply substrate 75 will be described with reference to FIGS. FIG. 3 is a perspective view showing a casing on which a main board and a power supply board are mounted, and FIG. 4 is a perspective view showing the main board and the casing separately.

  As shown in FIG. 3, the main body substrate 70 is disposed on the upper left side of the front plate 4 of the housing 2, and the power supply substrate 75 is disposed on the lower left side of the front plate 4.

  The main body substrate 70 has a substantially square shape, and a CPU, a memory, various electrical components, connectors, and the like are mounted on the front and back surfaces. The main body substrate 70 is supported by the front plate 4 and the support plate 40 of the housing 2 so as to be conductive. That is, as shown in FIG. 4, the main body substrate 70 is inserted into the screw holes 33 of the projecting pieces 32 formed on the left outer peripheral portion 26 of the front plate 4 at three locations P1, P2, and P3 along the left edge. It is concluded with a screw. Furthermore, at one place P4 near the center of the lower edge and three places P5, P6, and P7 along the right edge, the screw hole 62 of the projecting piece 61 cut and raised from the flat portion 60 of the bottom 41 of the support plate 40 is formed. It is concluded with a screw. Furthermore, it is supported by the front plate 4 of the housing 2 through the two conductive auxiliary pieces 72 so as to be conductive at two places P8 and P9 along the upper edge.

  As described above, the main body substrate 70 is arranged so that the right half substantially overlaps the outside of the flat portion 60 of the bottom 41 of the support plate 40 and the left half overlaps the outside of the front plate 4 of the housing 2. The main body substrate 70 is designed such that components mounted on the back surface are arranged such that a high-level component is arranged on the left side of the back-side surface and a low-level component is arranged on the right side. . That is, the component arranged on the left side of the back side surface is accommodated in a relatively high space between the main body substrate 70 and the front plate 4 of the housing 2, and the component arranged on the right side is the main substrate. 70 and a flat surface 60 of the support plate 40 are accommodated in a relatively low space.

  The power supply board 75 has a horizontally long rectangular shape, and components such as a capacitor and a transformer are mounted on the front and back surfaces. The power supply substrate 75 is disposed inside the lower edge portion 35 of the front plate 4 of the housing 2 below the main body substrate 70.

  Next, the lid 80 will be described with reference to FIG. FIG. 5 is a perspective view showing the lid and the housing separately.

  The lid 80 is made of a conductive material such as a sheet metal material, and covers a top plate 81 that covers the outer surfaces of the main body substrate 70 and the power supply substrate 75, an upper plate 82 bent backward from the upper edge of the top plate 81, A left side plate 83 bent rearward from the left edge of the top plate 81 and a lower step portion 84 along the lower edge of the top plate 81 are provided.

  The top plate 81 is formed with a notch 86 near the center of the right edge. Two screw holes 87 are formed above the notch 86 with a predetermined interval in the vertical direction. Below the notch 86, a predetermined interval in the left-right direction is provided near the center of the top plate 81. Three screw holes 88 are formed by opening. Further, an opening 91 for exposing a connector mounted on the main body substrate 70 is formed on the front surface of the top plate 81, and a vent hole 92 is formed on the lower portion.

  The upper plate 82 is formed with an upper edge portion 94 bent upward from the tip. Further, the upper plate 82 is formed with a slit 95 extending in the front-rear direction at substantially the center in the left-right direction, and screw holes 96 are formed in the upper edge portion 94 on both sides of the slit 95. The left side plate 83 is formed with five screw holes 97 having a predetermined interval in the vertical direction and a plurality of openings and notches. Further, an engaging portion 98 is formed in the lower step portion 84 with a predetermined interval in the left-right direction.

  In the lid 80, the top plate 81 covers the outside of the main body substrate 70 and the power supply substrate 75, the upper side plate 82 is fitted inside the upper outer peripheral portion 24 of the front plate 4 of the housing 2, and the left side plate 83 is the front plate. 4 is arranged so as to overlap the outside of the left outer peripheral portion 26 and the lower step portion 84 so as to overlap the outside of the lower edge portion 35 of the front plate 4. A screw hole 87 formed at the right edge of the top plate 81 is fastened with a screw hole 54 formed at the edge 53 of the motor mounting plate 50 with a screw, and a screw hole formed near the center of the top plate 81. 88 is fastened with screws to a screw hole 65 (see FIG. 2) formed in the lower edge portion 48 of the support plate 40, and is formed in the upper left corner of the front plate 4 and the screw hole 96 formed in the upper edge portion 94. The screw holes 21 are fastened with screws, and the screw holes 97 formed in the left side plate 83 and the screw holes 31 formed in the left outer peripheral portion 26 of the front plate 4 are fastened with screws, thereby 2 and the support plate 40 are supported so as to be conductive. Further, the engaging portion 98 of the lower step portion 84 of the lid 80 is engaged with the engaged portion 36 of the lower edge portion 35 of the front plate 4.

  In the image forming apparatus 1 having the above configuration, a state in which the main body substrate 70 is supported will be described with reference to FIGS. 6 (A) and 6 (B). 6A and 6B are diagrams schematically showing a state in which the main body substrate is supported. FIG. 6A is a transverse sectional view, and FIG. 6B is a longitudinal sectional view. .

  As shown in FIG. 6A, the main body substrate 70 is surrounded by the top plate 81 of the lid 80, the flat portion 60 of the support plate 40, and the front plate 4 of the housing 2 in the front-rear direction. In the direction, it is surrounded by the left outer peripheral portion 26 of the front plate 4 and the left side plate 83 of the lid 80 and the rising portion 52 of the motor mounting plate 50, and as shown in FIG. It is accommodated in the shield box 100 having a space surrounded by the upper plate 82 of the body 80 and the lower outer peripheral portion 25 of the front plate 4. That is, the internal space of the shield box 100 is formed in a shape in which the corners of the rectangular parallelepiped are partially cut out by the support plate 40.

  Note that the upper and lower portions of the motor mounting plate 50 are openings on the right side of the main board 70, and various cables are connected to the main board 70 and the power supply board 75 through these openings. Further, an interface connector or the like is attached through an opening or notch in the left side plate 83 of the lid 80 and the left outer peripheral portion 26 of the front plate 4.

  As described above, in the image forming apparatus of the present invention, the flat surface 60 of the support plate 40 that supports the drive transmission mechanism 10 is used as a part of the bottom plate of the shield box 100 in which the main body substrate 70 is accommodated. Therefore, the installation space for the main body substrate 70 can be reduced. Moreover, since the periphery of the main body substrate 70 is surrounded by the support plate 40 and the front plate 4 of the housing 2, the number of members constituting the shield box 100 can be reduced.

  Furthermore, since the lid 80 is fastened to the front plate 4 and the support plate 70 with screws at a relatively narrow pitch, the shielding performance of the shield box 100 can be enhanced.

  Furthermore, the internal space of the shield box 100 is not a simple rectangular parallelepiped shape, but is formed in a shape in which corners of the rectangular parallelepiped are partially cut out by the support plate 40. When the internal space of the shield box 100 has a rectangular parallelepiped shape, the electromagnetic wave generated from the main body substrate 70 accommodated may cause a cavity resonance phenomenon, and the electromagnetic wave of the resonance frequency component may be amplified and leak from the opening to the outside. In the image forming apparatus 1 of the invention, since the internal space of the shield box 100 is not a simple rectangular parallelepiped shape, the cavity resonance frequency can be dispersed and the amplification and leakage of electromagnetic waves can be prevented.

  Furthermore, on the back side surface of the main body substrate 70, the high-part components are accommodated in a space between the main body substrate 70 and the front plate 4 of the housing 2, and the low-part components are included in the main body substrate 70 and the support plate 40. Since it arrange | positions so that it may be accommodated in the space between these flat surfaces 60, the space | interval of the back surface of the main body board | substrate 70, the flat part 60 of the support plate 40, and the front plate 4 of the housing | casing 2 is possible as much as possible. Can be narrowed. Therefore, the space volume of the shield box 100 can be reduced, the loop current path can be reduced, and noise due to unnecessary radiation can be reduced.

  Furthermore, since the lid 80 is supported by the support plate 40 and the front plate 4 so as to be conductive and is not electrically connected to the main body substrate 70, when static electricity is generated in the lid 80, the static electricity It is possible to avoid a situation in which static electricity flows through the main body substrate 70 by being grounded via the housing 2. Therefore, the lid 80 can be used as an exterior cover, and the structure can be simplified and the cost can be reduced.

  In the present embodiment, the main body substrate 70 is supported by the front plate 4 and the support plate 40 of the housing 2 so as to be conductive, but may be supported by either the housing 2 or the support plate 40. For example, when the size of the main body substrate 70 is small, it can be supported only by the flat portion 60 of the support plate 40. Further, the lid 80 is also supported by the front plate 4 of the housing 2 and the motor mounting plate 50 provided on the support plate 40 so as to be conductive, but is supported by either the housing 2 or the support plate 40. Also good.

  Furthermore, since the above description of the embodiment of the present invention describes a preferred embodiment of the image forming apparatus according to the present invention, there may be various technically preferable limitations. The technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Housing | casing 10 Drive transmission mechanism 40 Support plate 41 Bottom part 42, 43, 44, 45 Outer peripheral part 70 Main body board | substrate (electric equipment board | substrate)
80 Lid 100 Shield Box

Claims (2)

An electroconductive housing in which the image forming unit is accommodated, an electroconductive support plate that supports the drive transmission mechanism of the image forming unit and is electrically connected to the housing, and an image forming operation of the image forming unit An image forming apparatus comprising: an electric board that controls the electric board; and a conductive lid that covers an outside of the electric board,
In order to shield the electrical board , the electrical board is fixed to at least the housing or the support body so as to face a part of the housing and a part of the support plate, and the lid body is an image forming apparatus comprising that you have been conductively supported on at least one of the housing or the support plate. The support plate is provided to protrude outward from the housing,
The internal space formed by a part of the support plate, a part of the housing, and the lid body has a shape in which a part of a corner of a rectangular parallelepiped is cut out by the support plate. Item 2. The image forming apparatus according to Item 1 .

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