JP2018146696A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus which can prevent electromagnetic noise without enlarging the device.SOLUTION: An image forming apparatus which can prevent electromagnetic noise without enlarging the device, is configured by arranging at least one of a stay 17 for supporting a laser scanner 3, a sheet metal 18 for supporting a circuit board 100, and a sheet metal 52 for supporting a drive unit 50, on each of side faces in four directions of the image forming apparatus, which are substantially perpendicular to an installation surface of the image forming apparatus, and by electrically connecting the conductive stay 17, sheet metal 18, and sheet metal 52 with each other, to form a shield plate.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus such as a printer or a copying machine.

  A circuit board provided in the image forming apparatus or a motor provided in the drive unit can be an electromagnetic noise generation source that generates electromagnetic noise. Such electromagnetic noise generated from the electromagnetic noise generation source may affect not only the inside of the image forming apparatus but also external equipment. In addition, electromagnetic noise from the outside of the image forming apparatus may affect the electrical operation of the circuit board.

  In Patent Document 1, an electric component and a motor serving as a drive source are provided in a lower portion of a recording material conveyance path. Also, the cable that is the source of noise is set short.

JP 2001-235919 A

  When the image forming apparatus is reduced in size and weight and cost is reduced, a conveyance guide constituting a recording material conveyance path and a side plate provided with a guide rail for mounting a process cartridge are integrally molded with a resin or the like. It may consist of. In this case, electromagnetic noise countermeasures are indispensable. As a countermeasure against electromagnetic noise, a shield metal plate may be additionally provided in four directions on the side surface of the apparatus that is perpendicular to the installation surface of the image forming apparatus. When such a shield sheet metal is added, the image forming apparatus is increased in size and weight.

  SUMMARY An advantage of some aspects of the invention is to provide an image forming apparatus capable of taking countermeasures against electromagnetic noise without increasing its size.

  In order to achieve the above object, a typical configuration of an image forming apparatus according to the present invention includes an exposure apparatus that exposes an image carrier, and a circuit board that is disposed in a direction substantially perpendicular to the installation surface of the image forming apparatus. A drive unit for supplying a driving force, and having conductivity, a first sheet metal that supports the exposure apparatus, and a second sheet metal that has conductivity and supports the circuit board, A third sheet metal that is electrically conductive and supports the drive unit, and each of the four side surfaces of the image forming apparatus that is substantially perpendicular to the installation surface of the image forming apparatus has the first plate At least one of the one sheet metal, the second sheet metal, and the third sheet metal is disposed, and the first sheet metal, the second sheet metal, and the third sheet metal are electrically connected to each other. It is connected.

  According to the present invention, it is possible to provide an image forming apparatus capable of taking countermeasures against electromagnetic noise without increasing the size.

1 is an explanatory cross-sectional view illustrating a configuration of a first embodiment of an image forming apparatus according to the present invention. FIG. 3 is a perspective explanatory view of the frame configuration of the image forming apparatus according to the first embodiment viewed from one side plate side. FIG. 3 is a perspective explanatory view of the frame configuration of the image forming apparatus according to the first embodiment viewed from the other side plate. FIG. 3 is an explanatory perspective view illustrating a state where a drive unit and an image signal line are attached to the main body of the image forming apparatus illustrated in FIG. 2. FIG. 4 is a perspective explanatory view showing a state in which a drive unit and an image signal line are attached to the main body of the image forming apparatus shown in FIG. 3. It is a perspective explanatory view showing the composition of the drive unit of a 1st embodiment. It is a perspective explanatory view showing the configuration of the circuit board of the first embodiment. FIG. 6 is a perspective explanatory view illustrating a configuration of a second embodiment of the image forming apparatus according to the present invention. FIG. 3 is an explanatory cross-sectional view illustrating a configuration of a comparative image forming apparatus. It is a perspective explanatory view showing a frame configuration of an image forming apparatus of a comparative example.

  An embodiment of an image forming apparatus according to the present invention will be specifically described with reference to the drawings.

[First Embodiment]
First, the configuration of the first embodiment of the image forming apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory cross-sectional view showing the configuration of the first embodiment of the image forming apparatus according to the present invention. FIG. 2 is an explanatory perspective view of the frame configuration of the image forming apparatus according to the first embodiment as viewed from one side plate side.

  FIG. 3 is an explanatory perspective view of the frame structure of the image forming apparatus according to the first embodiment as viewed from the other side plate. FIG. 4 is a perspective explanatory view showing a state in which a drive unit and image signal lines are attached to the main body of the image forming apparatus shown in FIG. FIG. 5 is an explanatory perspective view showing a state in which a drive unit and an image signal line are attached to the main body of the image forming apparatus shown in FIG. FIG. 6 is an explanatory perspective view illustrating the configuration of the drive unit according to the first embodiment. FIG. 7 is an explanatory perspective view illustrating the configuration of the circuit board according to the first embodiment.

<Image forming apparatus>
First, the configuration of the main body A of the image forming apparatus according to the present invention will be described with reference to FIG. The main body A of the image forming apparatus shown in FIG. 1 is an example of an electrophotographic laser beam printer. A process cartridge B is detachably mounted on the main body A of the image forming apparatus shown in FIG. In the process cartridge B, a photosensitive drum 8 as an image carrier, a charging roller 20 as a charging unit, a developing device 1 as a developing unit, a cleaner 2 as a cleaning unit, and the like are integrally provided in the frame. ing.

  On the upper part of the main body A, the open / close door 13 is rotatably supported. As shown by a broken line in FIG. 1, the process cartridge B becomes detachable from the main body A by opening the door 13. In the main body A, a laser scanner 3 serving as an exposure device that exposes the surface of the photosensitive drum 8 (image carrier) is provided.

  A feeding tray 4 for storing the recording material P is provided at the lower part of the main body A. The main body A is provided with a transport path R through which the recording material P is transported. In the transport path R, a feed roller 5, a transport roller 11, and a registration roller 6 are provided along the transport direction of the recording material P indicated by the arrow D direction in FIG.

  Further, a transfer roller 7 is provided as a transfer means for transferring the toner image formed on the surface of the photosensitive drum 8 to the recording material P. Further, a heating roller 9a, a pressure roller 9b, a discharge roller 10 and the like provided in the fixing device 9 serving as a fixing unit for fixing the toner image on the recording material P are sequentially arranged.

<Image forming operation>
The surface of the photosensitive drum 8 rotating in the clockwise direction in FIG. 1 is uniformly charged by a charging roller 20 serving as charging means. Thereafter, the surface of the uniformly charged photosensitive drum 8 is irradiated with laser light L corresponding to the image information by the laser scanner 3 serving as image exposure means, thereby forming an electrostatic latent image. Thereafter, the electrostatic latent image formed on the surface of the photosensitive drum 8 is supplied with toner as a developer by a developing roller 21 as a developer carrying member provided in the developing device 1 serving as a developing unit. Developed as an image.

  On the other hand, in accordance with the output timing of the laser light L emitted from the laser scanner 3, it is accommodated in the feed tray 4 by the feed roller 5 to which the rotational driving force of the motor 51 is transmitted by the drive unit 50 shown in FIG. The recorded material P is fed out. Thereafter, the recording material P is separated and fed one by one in cooperation with a separating means (not shown). Thereafter, the recording material P is nipped and conveyed by the conveying roller 11, and the leading end abuts against the nip portion of the stopped registration roller 6 to correct the skew. Thereafter, the registration roller 6 rotates at a predetermined timing, and the recording material P is conveyed to a transfer nip portion N1 formed by the photosensitive drum 8 and the transfer roller 7 serving as a transfer unit.

  In synchronization with the toner image formed on the surface of the photosensitive drum 8, the recording material P sandwiched and conveyed by the registration roller 6 reaches the transfer nip portion N1. Then, a transfer bias is applied to the transfer roller 7 from a transfer bias power source (not shown), and the toner image formed on the surface of the photosensitive drum 8 is transferred to the recording material P. Residual toner remaining on the surface of the photosensitive drum 8 after the transfer is scraped off and removed by a cleaning blade 22 serving as a cleaning unit.

  The recording material P onto which the toner image has been transferred is nipped and conveyed by the photosensitive drum 8 and the transfer roller 7 and conveyed to a fixing device 9 serving as a fixing unit. The recording material P carrying the toner image is nipped and conveyed by the heating roller 9a and the pressure roller 9b. In this process, the toner image on the recording material P is heated and pressurized and thermally fixed to the recording material P.

  Thereafter, the recording material P is nipped and conveyed by the discharge roller 10 and discharged onto a discharge tray 13 a constituted by the upper surface of the open / close door 13.

  In the main body A of the image forming apparatus, a conveyance guide 14 constituting the conveyance path R and a stay 17 for fixing and supporting the laser scanner 3 are provided so as to extend in the longitudinal direction of the main body A (left and right direction in FIG. 2). Yes. Side plates 15 and 16 are provided opposite to both ends of the conveyance guide 14 and the stay 17 in the longitudinal direction (left and right direction in FIG. 2). Both ends of the conveyance guide 14 and the stay 17 in the longitudinal direction (left and right direction in FIG. 2) and the side plates 15 and 16 are connected to each other. Inside the side plates 15 and 16, guide rails 15a and 16a are provided for guiding the process cartridge B when the process cartridge B is attached to and detached from the main body A, respectively.

  As shown in FIGS. 4 and 5, a drive unit 50 is provided outside the side plate 15. As shown in FIGS. 2 to 5, a circuit board 100 is provided on the outside of the conveyance guide 14 so as to be arranged in a direction substantially perpendicular to the installation surface of the main body A of the image forming apparatus.

<Frame body configuration>
Next, the frame configuration of the main body A of the image forming apparatus will be described with reference to FIGS. 2 to 5 is the longitudinal direction of the main body A of the image forming apparatus, and is the axial direction of each roller that conveys the recording material P such as the transfer roller 7.

  The laser scanner 3 (exposure apparatus) of the present embodiment is fixed to the outer surface side of a stay 17 (first sheet metal) having a U-shaped cross section having conductivity by a fixing means such as a screw. The surface of the stay 17 on which the laser scanner 3 is installed is substantially orthogonal to the installation surface of the main body A. As shown in FIGS. 2 and 3, the stay 17 is pulled by a tension spring 17 a serving as a biasing means outside the side plates 15 and 16.

  One end portions of the pair of tension springs 17 a that urge the stay 17 are respectively engaged with both longitudinal end portions of the stay 17. The other end of one tension spring 17a is locked to the conductive sheet metal 52 shown in FIG. 4, and the other end of the other tension spring 17a is locked to the conductive sheet metal 18 shown in FIG. Has been. The pair of tension springs 17a are elastic members having conductivity.

  On the back side of the main body A, the circuit board 100 is fixed to the outside of the conveyance guide 14 by fixing means such as screws. The surface of the circuit board 100 is substantially orthogonal to the installation surface of the main body A of the image forming apparatus. The circuit board 100 is disposed in parallel with the arrow M direction. As shown in FIG. 1, the installation surface 3 a of the laser scanner 3 (exposure apparatus) with respect to the stay 17 is substantially orthogonal to the installation surface of the main body A. Thereby, the installation surface 3a and the substrate surface 100a of the circuit board 100 are in a substantially parallel positional relationship. As shown in FIGS. 2 to 5, the laser scanner 3 (exposure device) and the circuit board 100 are disposed substantially in parallel in the main body A (in the main body) of the image forming apparatus.

<Drive unit>
Next, the configuration of the drive unit 50 will be described with reference to FIG. As shown in FIGS. 4 and 5, a drive unit 50 is provided outside the side plate 15. The driving unit 50 supplies driving force to each driving unit of the image forming apparatus. As shown in FIG. 6, the drive unit 50 has a configuration in which a gear train is supported on a conductive metal plate 52 (third metal plate). A plurality of gears 12 a to 12 h are rotatably supported on the sheet metal 52.

  A motor 51 serving as a driving source is fixed to the side plate 15 by a fixing member such as a screw (not shown). The drive gear 51a fixed to the drive shaft of the motor 51 is meshed with the gears 12a and 12g, respectively. The gear 12a is meshed with the gear 12b, the gear 12b is meshed with the gear 12c, and the gear 12c is meshed with the gears 12d and 12f, respectively. Furthermore, the gear 12d is meshed with the gear 12e. The gear 12g is meshed with the gear 12h.

  As a result, the rotational driving force of the motor 51 is supplied to the feed roller 5, the transport roller 11, the registration roller 6, the photosensitive drum 8, the heating roller 9a, and the pressure roller shown in FIG. 9b and the discharge roller 10, respectively.

  As shown in FIGS. 2 to 5, the transfer roller 7 is rotatably supported at both ends of the conveyance guide 14 in the arrow M direction via a pair of bearing members 7 a. The transfer roller 7 is provided so as to apply a predetermined contact pressure to the surface of the photosensitive drum 8 by a pressing spring 7b serving as an urging unit attached to the bearing member 7a.

  The transfer roller 7 contacts the surface of the photosensitive drum 8 to form a transfer nip portion N1. A transfer bias is applied to the transfer roller 7 from a transfer bias power source (not shown). Thus, the toner image formed on the surface of the photosensitive drum 8 is transferred to the recording material P that is nipped and conveyed by the registration roller 6. The transfer roller 7 provided in the conveyance guide 14 is not connected to the gear train 12 shown in FIG. 6 and rotates following the rotation of the photosensitive drum 8.

  In the transfer nip portion N1, the recording material P on which the toner image has been transferred is conveyed to the fixing device 9 via the conveyance path R. The fixing device 9 is provided with a pressure roller 9b and a heating roller 9a supported so as to be rotatable with respect to the frame body 9c. The frame 9c of the fixing device 9 is fixed to the upper surface portions of the side plates 15 and 16 by fixing members such as screws (not shown). A driving gear (not shown) is fixed to one end of the rotating shaft of the pressure roller 9b in the longitudinal direction. The driving gear of the pressure roller 9b meshes with the gear 12d of the gear train 12 shown in FIG. As a result, the rotational driving force from the motor 51 as the driving source is transmitted to the pressure roller 9b via the gear train 12, and the pressure roller 9b rotates.

  In the transfer nip portion N1, the recording material P to which the toner image has been transferred is heated and pressed in the process of passing through the fixing nip portion N2 formed by the heating roller 9a and the pressure roller 9b. As a result, the toner image is melted and fixed on the recording material P. Thereafter, the recording material P on which the toner image is fixed is nipped and conveyed by the discharge roller 10 and is discharged onto a discharge tray 13 a provided on the open / close door 13.

<Circuit board>
Next, the configuration of the circuit board 100 will be described with reference to FIG. The circuit board 100 shown in FIG. 7 is provided with a low-voltage power supply element 110 that takes in AC power from an external commercial power source and converts it into DC power. Further, a high voltage power supply element 120 for supplying a high voltage necessary for image formation to the process cartridge B and the transfer roller 7 is provided.

  The circuit board 100 of the present embodiment integrally mounts electronic elements including a low-voltage power supply element portion 110 made of a low-voltage power supply element and a high-voltage power supply element portion 120 made of a high-voltage power supply element. The circuit board 100 shown in FIG. 7 is further provided with a plurality of conveyance sensors 130 for detecting the conveyance state of the recording material P conveyed along the conveyance path R. Further, in order to send an image signal to the laser scanner 3, a connector part 140 for connecting the image signal lines 150 and 151 shown in FIGS. 4 and 5 is mounted.

  In the present embodiment, a plurality of electronic elements of the low-voltage power element unit 110 and the high-voltage power element unit 120 are mounted in a direction perpendicular to the substrate surface 100 a of the circuit board 100. Among these plural electronic elements, the tallest electronic element protruding from the substrate surface 100 a of the circuit board 100 is a low-voltage power transformer 111 that is a part of the low-voltage power element unit 110. For this reason, the apex T of the low-voltage power transformer 111 is the most protruding portion with respect to the vertical direction of the circuit board 100.

  The circuit board 100 is provided substantially parallel to the conveyance path R of the recording material P arranged in the vertical direction in FIG. The circuit board 100 side of the conveyance path R is configured by a conveyance guide 14 arranged in the vertical direction in FIG. A space 19 is formed between the substrate surface 100 a of the circuit board 100 and the transport guide 14. The low-voltage power element unit 110 and the high-voltage power element unit 120 that are electronic elements mounted on the circuit board 100 are accommodated in a space 19 formed between the conveyance guide 14 and the circuit board 100.

  Here, points 6a, 7c, and 9b1 where the surfaces of the transport roller 11, the registration roller 6, the transfer roller 7, and the pressure roller 9b are closest to the substrate surface 100a of the circuit board 100 are taken into consideration (reference numerals of the points of the transport roller 11). Is omitted). Of these points 6a, 7c and 9b1, a plane V1 passing through the point closest to the circuit board 100 and parallel to the substrate surface 100a of the circuit board 100 is considered. The interior of the main body A is laid out so that the apex T of the low-voltage power transformer 111 protrudes further toward the transport path R (right side in FIG. 1) than the surface V1.

  Accordingly, it is not necessary to expand the front-rear direction (the left-right direction in FIG. 1) of the main body A of the image forming apparatus in order to accommodate the low-voltage power transformer 111, and the image forming apparatus can be downsized.

  Further, a low-voltage power element unit 110 including a low-voltage power transformer 111 is disposed below the transfer roller 7 shown in FIG. As a result, the center of gravity of the main body A is located on the lower side, so that the main body A can be stabilized.

  Further, a low-voltage power element unit 110 including a low-voltage power transformer 111 is disposed at a position away from the fixing device 9 shown in FIG. As a result, it is possible to suppress malfunctions due to the influence of heat generated in the fixing device 9. In addition, the air heated by the low-voltage power source element 110 flows upward in FIG. 1 by natural convection in the space 19 formed between the conveyance guide 14 and the circuit board 100. As a result, efficient exhaust heat can be obtained.

<Electromagnetic noise countermeasures>
Next, electromagnetic noise countermeasures of the image forming apparatus will be described with reference to FIGS. The circuit board 100 can also be an electromagnetic noise generation source that generates electromagnetic noise. The generation of electromagnetic noise affects not only the inside of the image forming apparatus but also equipment outside the image forming apparatus.

  In particular, the shield effect by the conductor cannot be expected only by fixing the circuit board 100 to the transport guide 14 which is a non-conductor as in the present embodiment. For this reason, there is a high possibility that electromagnetic noise generated from the circuit board 100 is radiated and spread to various places. In the present embodiment, a sheet metal 18 (second sheet metal) having conductivity that shields electromagnetic noise generated from the circuit board 100 is provided outside the circuit board 100 (see FIGS. 1 and 3). The sheet metal 18 fixes the circuit board 100 together with the conveyance guide 14 to the main body A of the image forming apparatus. The sheet metal has a length extending from one of the two side plates 15 to the other side plate 16.

  The sheet metal 18 (second sheet metal) is fastened to the circuit board 100 and the conductive sheet metal 52 (third sheet metal) shown in FIGS. 4 and 5 by a fixing member (not shown) such as a conductive screw. Has been. The sheet metal 18 (second sheet metal) and the sheet metal 52 (third sheet metal) are electrically connected to the conductive stay 17 (first sheet metal) via the tension spring 17a. In the present embodiment, the stay 17 and the sheet metal 18, and the stay 17 and the sheet metal 52 are electrically connected by a tension spring 17 a having conductivity. Accordingly, the stay 17 (first sheet metal), the sheet metal 18 (second sheet metal), and the sheet metal 52 (third sheet metal) are connected to have the same potential. In addition, the stay 17 and the sheet metal 18 and the stay 17 and the sheet metal 52 may be electrically connected by a conductive screw or the like. Further, at least one of the connecting portions that electrically connect the stay 17 (first sheet metal), the sheet metal 18 (second sheet metal), and the sheet metal 52 (third sheet metal) is electrically conductive. It can be connected by an elastic member such as a tension spring 17a having

  In this embodiment, the sheet metal 18 (second sheet metal), the sheet metal 52 (third sheet metal), and the stay 17 (first sheet metal) cover the four side surfaces of the image forming apparatus and serve as shield plates. Yes. As a result, electromagnetic noise can be shielded and electromagnetic noise from the outside of the image forming apparatus can be prevented from affecting the electrical operation of the circuit board 100. In addition, electromagnetic noise generated from various power supply elements of the low-voltage power supply element unit 110 and the high-voltage power supply element unit 120 mounted on the circuit board 100 can be suppressed from affecting external devices. In this manner, the stay 17 (first sheet metal), the sheet metal 18 (second sheet metal), and the sheet metal 52 (on the side surfaces in the direction substantially perpendicular to the installation surface of the image forming apparatus and in the four directions of the image forming apparatus). Preferably, at least one of the third sheet metal) is arranged and electrically connected to each other.

  As shown in FIGS. 4 and 5, the image signal lines 150 and 151 for connecting the connector portion 140 provided on the circuit board 100 and the laser scanner 3 include a stay 17 configured as a shield plate, and a sheet metal. 18 and near the outside of the sheet metal 52. Thereby, it is possible to suppress the electromagnetic noise generated from various power supply elements of the low voltage power supply element unit 110 and the high voltage power supply element unit 120 mounted on the circuit board 100 from affecting the image signal lines 150 and 151. Thereby, the laser scanner 3 can be protected from electromagnetic noise.

<Comparative example>
Next, the configuration of a comparative image forming apparatus will be described with reference to FIGS. FIG. 9 is a cross-sectional explanatory diagram illustrating the configuration of the main body A of the image forming apparatus of the comparative example. FIG. 10 is an explanatory perspective view showing the frame structure of the main body A of the image forming apparatus of the comparative example.

  The main body A of the image forming apparatus of the comparative example is also provided with a conveyance guide 14 that constitutes the conveyance path R. Further, in the main body A of the image forming apparatus of the comparative example, the plane (fixed surface) of the stay 17 for fixing the laser scanner 3 is provided in parallel with the installation surface of the image forming apparatus.

  In addition, side plates 15 and 16 disposed opposite to each other are supported by being connected to both ends of the conveyance guide 14 and the stay 17 in the longitudinal direction. A drive unit 50 is disposed outside the side plate 15, and a circuit board 100 is disposed outside the side plate 16. The low-voltage power element unit 110 and the high-voltage power element unit 120 mounted on the circuit board 100 protrude from the substrate surface 100a of the circuit board 100 toward the outside of the main body A of the image forming apparatus. When the circuit board 100 is arranged in this manner, the size of the image forming apparatus is increased.

  On the other hand, in the present embodiment shown in FIG. 1, the circuit board 100 on which a plurality of electronic elements such as the low-voltage power supply element unit 110 and the high-voltage power supply element unit 120 are mounted is disposed on the back side of the main body A of the image forming apparatus. Arrange substantially perpendicular to the installation surface. Then, the low voltage power supply element portion 110 protruding from the substrate surface 100a of the circuit board 100, the tall power supply element of the high voltage power supply element portion 120, and the like are arranged so as to protrude forward of the image forming apparatus toward the conveyance path R side. .

  These power supply elements are accommodated in a space 19 formed between the conveyance guide 14 and the circuit board 100. As a result, the main body A of the image forming apparatus does not increase in size in the front-rear direction (left-right direction in FIG. 1). In comparison with the comparative example shown in FIGS. 9 and 10, in this embodiment, the image forming apparatus can be downsized.

  Further, according to the present embodiment, even if the resin side plates 15 and 16 are used, electromagnetic noise countermeasures can be taken without increasing the size of the apparatus.

[Second Embodiment]
Next, the configuration of the second embodiment of the image forming apparatus according to the present invention will be described with reference to FIG. FIG. 8 is a perspective explanatory view showing the configuration of the second embodiment of the image forming apparatus according to the present invention. In addition, what was comprised similarly to 1st Embodiment attaches | subjects the same member name even if the same code | symbol or a code | symbol differs, and abbreviate | omits description.

  The image forming apparatus according to the first embodiment has a configuration in which the laser scanner 3 is arranged outside the main body A of the image forming apparatus with respect to the stay 17. As shown in FIG. 8, the image forming apparatus according to the present embodiment has a configuration in which the stay 17 is disposed outside the main body A of the image forming apparatus with respect to the laser scanner 3. The laser scanner 3 of the present embodiment is supported by being fixed to the inner surface side of the stay 17 having a U-shaped cross section by a fixing means such as a screw.

  Also in this embodiment, the conductive metal plates 18 and 52 and the stay 17 are configured to cover the side surfaces in the four directions of the main body A of the image forming apparatus in a direction substantially perpendicular to the installation surface of the main body A of the image forming apparatus. It has become. As a result, the metal plates 18 and 52 and the stay 17 serve as shield plates.

  In the present embodiment, a stay 17 configured as a shield plate is provided outside the laser scanner 3. Therefore, the image signal lines 150 and 151 are arranged close to the inside of the stay 17. Thereby, the influence of electromagnetic noise on the electrical operation of the laser scanner 3 can be suppressed.

  In addition, electromagnetic noise from the outside of the image forming apparatus is shielded by the stay 17 and can be prevented from affecting the electrical operation of a scanner motor and a laser substrate (not shown) provided inside the laser scanner 3. Further, it is possible to prevent electromagnetic noise generated from the inside of the laser scanner 3 from spreading outside the image forming apparatus. Other configurations are the same as those in the first embodiment, and the same effects can be obtained.

A ... Main body 3 of image forming apparatus ... Laser scanner (exposure device)
17 ... Stay (first sheet metal)
18 ... Sheet metal (second sheet metal)
50 ... Drive unit 52 ... Sheet metal (third sheet metal)
100 ... Circuit board

Claims (5)

An exposure apparatus for exposing the image carrier;
A circuit board disposed substantially perpendicular to the installation surface of the image forming apparatus;
A driving unit for supplying driving force;
Have
A first sheet metal having electrical conductivity and supporting the exposure apparatus;
A second sheet metal having electrical conductivity and supporting the circuit board;
A third sheet metal having electrical conductivity and supporting the drive unit;
Have
At least one of the first sheet metal, the second sheet metal, and the third sheet metal is disposed on each side surface in a direction substantially perpendicular to the installation surface of the image forming apparatus and in four directions of the image forming apparatus. And
The image forming apparatus, wherein the first sheet metal, the second sheet metal, and the third sheet metal are electrically connected to each other. The image forming apparatus according to claim 1, wherein the exposure apparatus and the circuit board are disposed substantially in parallel within a main body of the image forming apparatus.   The image forming apparatus according to claim 1, wherein the first sheet metal, the second sheet metal, and the third sheet metal are connected to have the same potential. .   At least one of the connection portions that electrically connect the first sheet metal, the second sheet metal, and the third sheet metal to each other is connected by an elastic member having conductivity. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   A signal line connecting the exposure apparatus and the circuit board is disposed in proximity to at least one of the first sheet metal, the second sheet metal, and the third sheet metal. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

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