JP6987512B2 - Image forming device - Google Patents

Description

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

A motor provided in a circuit board or a drive unit provided in an image forming apparatus can be a source of electromagnetic noise that generates electromagnetic noise. The electromagnetic noise generated from such an electromagnetic noise generation source may affect not only the inside of the image forming apparatus but also an external device. 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 electrical component and a motor serving as a drive source are provided in the lower part of the recording material transport path. In addition, the cable that causes noise is set short.

Japanese Unexamined Patent Publication No. 2001-235919

In order to reduce the size, weight and cost of the image forming apparatus, the transport guide that constitutes the transport path for the recording material and the side plate provided with the guide rail for mounting the process cartridge are integrally molded with resin or the like. May consist of. In this case, measures against electromagnetic noise are indispensable. As a measure against electromagnetic noise, shield sheet metal may be additionally provided in four directions on the side surface of the device, which is perpendicular to the installation surface of the image forming device. When such a shield sheet metal is added, the image forming apparatus becomes large and the weight increases.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus capable of taking measures against electromagnetic noise without increasing the size.

A typical configuration of the image forming apparatus according to the present invention for achieving the above object is an exposure apparatus for exposing an image carrier and a circuit board arranged substantially perpendicular to the installation surface of the image forming apparatus. A first sheet metal having a driving unit for supplying a driving force, having conductivity and supporting the exposure apparatus, and a second sheet metal having conductivity and supporting the circuit board. It has a third sheet metal that is conductive and supports the drive unit, and is substantially perpendicular to the installation surface of the image forming apparatus and on at least three side surfaces of the four directions of the image forming apparatus. Is arranged so that at least one of the first sheet metal, the second sheet metal, and the third sheet metal is arranged so as to surround the image carrier, and the second sheet metal carries the image more than the circuit board. Located at an outer position away from the body, it has a pair of resin side plates that support both ends of the image carrier in the longitudinal direction of the image carrier, the second sheet metal in the longitudinal direction. It is characterized by having a length extending from one said side plate to the other said side plate.
Further, a typical configuration of the image forming apparatus according to the present invention for achieving the above object is an exposure apparatus for exposing an image carrier and a circuit arranged substantially perpendicular to the installation surface of the image forming apparatus. A first sheet metal that has a substrate and a drive unit that supplies driving force and has conductivity and supports the exposure apparatus, and a second sheet metal that has conductivity and supports the circuit board. And a third sheet metal that is conductive and supports the drive unit, and is substantially perpendicular to the installation surface of the image forming apparatus and at least three of the four directions of the image forming apparatus. At least one of the first sheet metal, the second sheet metal, and the third sheet metal is arranged so as to surround the image carrier, and the second sheet metal is more than the circuit board. It is located at an outer position away from the image carrier, and at least one of the connection portions that electrically connects the first sheet metal, the second sheet metal, and the third sheet metal to each other. Is characterized by being connected by an elastic member having conductivity.

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

It is sectional drawing which shows the structure of 1st Embodiment of the image forming apparatus which concerns on this invention. It is a perspective explanatory view which saw the frame body structure of the image forming apparatus of 1st Embodiment from one side plate side. It is a perspective explanatory view which saw the frame body structure of the image forming apparatus of 1st Embodiment from the other side plate side. FIG. 3 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. 2. FIG. 3 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. It is a perspective explanatory drawing which shows the structure of the drive unit of 1st Embodiment. It is a perspective explanatory drawing which shows the structure of the circuit board of 1st Embodiment. It is a perspective explanatory drawing which shows the structure of the 2nd Embodiment of the image forming apparatus which concerns on this invention. It is sectional drawing which shows the structure of the image forming apparatus of a comparative example. It is a perspective explanatory view which shows the frame structure of the image forming apparatus of a comparative example.

An embodiment of the 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. 1 to 7. FIG. 1 is a cross-sectional explanatory view showing the configuration of the first embodiment of the image forming apparatus according to the present invention. FIG. 2 is a perspective explanatory view of the frame structure of the image forming apparatus of the first embodiment as viewed from one side plate side.

FIG. 3 is a perspective explanatory view of the frame structure of the image forming apparatus of the first embodiment as viewed from the other side plate side. 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. FIG. 5 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. FIG. 6 is a perspective explanatory view showing the configuration of the drive unit of the first embodiment. FIG. 7 is a perspective explanatory view showing the configuration of the circuit board of the first embodiment.

<Image forming device>
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 attached to the main body A of the image forming apparatus shown in FIG. 1. The process cartridge B is integrally provided with a photosensitive drum 8 as an image carrier, a charging roller 20 as a charging means, a developing device 1 as a developing means, a cleaner 2 as a cleaning means, and the like. ing.

An opening / closing door 13 is rotatably supported on the upper part of the main body A. As shown by the broken line in FIG. 1, the process cartridge B can be attached to and detached from the main body A by opening the opening / closing door 13. A laser scanner 3 serving as an exposure device for exposing the surface of the photosensitive drum 8 (image carrier) is provided in the main body A.

A feed tray 4 for accommodating 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 for transporting the recording material P. The transport path R is provided with a feed roller 5, a transport roller 11, and a resist roller 6 along the transport direction of the recording material P indicated by the arrow D in FIG. 1.

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 means for fixing the toner image on the recording material P are sequentially arranged.

<Image formation operation>
The surface of the photosensitive drum 8 that rotates clockwise in FIG. 1 is uniformly charged by the charging roller 20 that serves as a charging means. After that, the surface of the uniformly charged photosensitive drum 8 is irradiated with the laser beam L corresponding to the image information by the laser scanner 3 serving as an image exposure means, and an electrostatic latent image is formed. After that, 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 carrier provided in a developing apparatus 1 serving as a developing means. Developed as an image.

On the other hand, in combination with the output timing of the laser beam L emitted from the laser scanner 3, the feeding roller 5 transmits the rotational driving force of the motor 51 by the driving unit 50 shown in FIG. 6 to accommodate the laser beam L in the feeding tray 4. The recording material P is fed out. After that, the recording materials P are separated and fed one by one in collaboration with a separation means (not shown). After that, the recording material P is sandwiched and conveyed by the conveying roller 11, and the tip portion abuts against the nip portion of the stopped resist roller 6 to correct the skew. After that, the resist roller 6 rotates at a predetermined timing, and the recording material P is conveyed to the transfer nip portion N1 formed by the photosensitive drum 8 and the transfer roller 7 serving as the transfer means.

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

The recording material P on which the toner image is transferred is sandwiched and conveyed by the photosensitive drum 8 and the transfer roller 7, and is conveyed to the fixing device 9 which is a fixing means. The recording material P carrying the toner image is sandwiched 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 to be heat-fixed to the recording material P.

After that, the recording material P is sandwiched and conveyed by the discharge roller 10 and discharged onto the discharge tray 13a configured on the upper surface of the opening / closing door 13.

The main body A of the image forming apparatus is provided with a transport guide 14 constituting the transport path R and a stay 17 for fixing and supporting the laser scanner 3 so as to extend in the longitudinal direction of the main body A (left-right direction in FIG. 2). There is. Side plates 15 and 16 are provided facing both ends of the transport guide 14 and the stay 17 in the longitudinal direction (left-right direction in FIG. 2). Both ends of the transport guide 14 and the stay 17 in the longitudinal direction (left-right direction in FIG. 2) and the side plates 15 and 16 are connected, respectively. Guide rails 15a and 16a are provided inside the side plates 15 and 16 to guide the process cartridge B when it is attached to and detached from the main body A, respectively.

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

<Frame structure>
Next, the frame structure of the main body A of the image forming apparatus will be described with reference to FIGS. 2 to 5. The arrow M direction in 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 17a serving as a urging means on the outside of the side plates 15 and 16.

One end of the pair of tension springs 17a urging the stay 17 is locked to both ends of the stay 17 in the longitudinal direction. 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 done. 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 transport guide 14 by a fixing means such as a screw. 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 arranged parallel to the arrow M direction. As shown in FIG. 1, the installation surface 3a of the laser scanner 3 (exposure device) with respect to the stay 17 is substantially orthogonal to the installation surface of the main body A. As a result, the installation surface 3a and the substrate surface 100a of the circuit board 100 are in a substantially parallel positional relationship. Further, as shown in FIGS. 2 to 5, the laser scanner 3 (exposure apparatus) and the circuit board 100 are arranged substantially in parallel in the main body A (inside 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 on the outside of the side plate 15. The drive unit 50 supplies a driving force to each drive 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 by a conductive sheet metal 52 (third sheet metal). A plurality of gears 12a to 12h are rotatably supported on the sheet metal 52.

A motor 51 as a drive 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. Further, the gear 12d is meshed with the gear 12e. Further, the gear 12g is meshed with the gear 12h.

As a result, the rotational driving force of the motor 51 is the feed roller 5, the transfer roller 11, the resist roller 6, the photosensitive drum 8, the heating roller 9a, and the pressurizing roller shown in FIG. 1 by the gear train 12 composed of the plurality of gears 12a to 12h. It is transmitted to each of 9b and the discharge roller 10.

As shown in FIGS. 2 to 5, transfer rollers 7 are rotatably supported at both ends of the transport guide 14 in the arrow M direction via a pair of bearing members 7a. 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 as a urging means attached to the bearing member 7a.

The transfer roller 7 abuts on the surface of the photosensitive drum 8 to form the transfer nip portion N1. A transfer bias is applied to the transfer roller 7 from a transfer bias power supply (not shown). As a result, the toner image formed on the surface of the photosensitive drum 8 is transferred to the recording material P which has been sandwiched and conveyed by the resist roller 6. The transfer roller 7 provided on the transfer guide 14 is not connected to the gear train 12 shown in FIG. 6, and rotates driven by the rotation of the photosensitive drum 8.

In the transfer nip portion N1, the recording material P on which the toner image is transferred is transferred to the fixing device 9 via the transfer path R. The fixing device 9 is provided with a pressure roller 9b and a heating roller 9a that are rotatably supported with respect to the frame body 9c. The frame body 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 drive gear (not shown) is fixed to one end of the rotary shaft of the pressurizing roller 9b in the longitudinal direction. The drive gear of the pressurizing 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, which is the drive source, is transmitted to the pressurizing roller 9b via the gear train 12, and the pressurizing roller 9b rotates.

In the transfer nip portion N1, the recording material P on which the toner image is transferred is heated and pressurized in the process of passing through the fixing nip portion N2 formed by the heating roller 9a and the pressurizing roller 9b. As a result, the toner image is melted and fixed to the recording material P. After that, the recording material P on which the toner image is fixed is sandwiched and conveyed by the discharge roller 10 and discharged onto the discharge tray 13a provided on the opening / closing door 13.

<Circuit board>
Next, the configuration of the circuit board 100 will be described with reference to FIG. 7. The circuit board 100 shown in FIG. 7 is provided with a low-voltage power element unit 110 that takes in AC power from an external commercial power source and converts it into DC power. Further, a high-voltage power element unit 120 for supplying the high voltage required 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 an electronic element including a low-voltage power element unit 110 made of a low-voltage power element and a high-voltage power element 120 made of a high-voltage power element. The circuit board 100 shown in FIG. 7 is further provided with a plurality of transport sensors 130 for detecting the transport state of the recording material P transported along the transport path R. Further, a connector unit 140 or the like for connecting the image signal lines 150 and 151 shown in FIGS. 4 and 5 to send the image signal to the laser scanner 3 is mounted.

In this embodiment, a plurality of electronic elements of a low-voltage power supply element unit 110 and a high-voltage power supply element unit 120 are mounted in a direction perpendicular to the substrate surface 100a of the circuit board 100. Among these plurality of electronic elements, the tallest electronic element protruding from the substrate surface 100a of the circuit board 100 is the low-voltage power transformer 111 which is a part of the low-voltage power element unit 110. Therefore, the apex portion 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 transport path R of the recording material P arranged in the vertical direction of FIG. The circuit board 100 side of the transport path R is composed of transport guides 14 arranged in the vertical direction of FIG. A space 19 is formed between the substrate surface 100a 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, which are electronic elements mounted on the circuit board 100, are housed in a space 19 formed between the transfer guide 14 and the circuit board 100.

Here, the points 6a, 7c, 9b1 in which the surfaces of the transfer roller 11, the resist roller 6, the transfer roller 7, and the pressure roller 9b are closest to the substrate surface 100a of the circuit board 100 are considered (the reference numerals of the points of the transfer roller 11). Is omitted). Consider the plane V1 that passes through the points 6a, 7c, 9b1 closest to the circuit board 100 and is parallel to the substrate surface 100a of the circuit board 100. The inside of the main body A is laid out so that the apex portion T of the low voltage power transformer 111 projects toward the transport path R side (right side in FIG. 1) with respect to the surface V1.

As a result, it is not necessary to widen the front-rear direction (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 miniaturized.

Further, the low-voltage power element unit 110 including the low-voltage power transformer 111 is arranged 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, the low-voltage power element unit 110 including the low-voltage power transformer 111 is arranged at a position away from the fixing device 9 shown in FIG. As a result, it is possible to suppress malfunctions and the like due to the influence of heat generated in the fixing device 9. Further, the air heated by the low-voltage power element unit 110 flows upward in FIG. 1 by natural convection in the space 19 formed between the transport guide 14 and the circuit board 100. This makes it possible to efficiently exhaust heat.

<Countermeasures against electromagnetic noise>
Next, countermeasures against electromagnetic noise of the image forming apparatus will be described with reference to FIGS. 4 and 5. 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 the external equipment of the image forming apparatus.

In particular, as in the present embodiment, the shielding effect of the conductor cannot be expected only by fixing the circuit board 100 to the transport guide 14 which is a non-conductor. Therefore, there is a high possibility that the electromagnetic noise generated from the circuit board 100 is radiated to various places and spreads. In the present embodiment, a conductive sheet metal 18 (second sheet metal) that shields electromagnetic noise generated from the circuit board 100 is provided on the outside of the circuit board 100 (see FIGS. 1 and 3). The sheet metal 18 fixes the circuit board 100 to the main body A of the image forming apparatus together with the transport guide 14. The sheet metal has a length extending from 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 done. 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 a 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 17a having conductivity, respectively. As a result, the stay 17 (first sheet metal), the sheet metal 18 (second sheet metal), and the sheet metal 52 (third sheet metal) are connected so as to have the same potential. Alternatively, the stay 17 and the sheet metal 18 and the stay 17 and the sheet metal 52 may be electrically connected by a screw or the like having conductivity. Further, at least one of the connecting portions for electrically connecting the stay 17 (first sheet metal), the sheet metal 18 (second sheet metal), and the sheet metal 52 (third sheet metal) is conductive. It can be connected by an elastic member such as a tension spring 17a having the above.

In the present embodiment, the sheet metal 18 (second sheet metal), the sheet metal 52 (third sheet metal), and the stay 17 (first sheet metal) cover the side surfaces of the image forming apparatus in four directions and serve as a shield plate. There is. As a result, electromagnetic noise can be shielded, and electromagnetic noise from the outside of the image forming apparatus can be suppressed from affecting the electrical operation of the circuit board 100. Further, it is possible to suppress the influence of 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 on external devices and the like. In this way, the stay 17 (first sheet metal), the sheet metal 18 (second sheet metal), and the sheet metal 52 (the stay 17 (first sheet metal), the sheet metal 18 (the second sheet metal), and the sheet metal 52 (on each side surface in the direction substantially perpendicular to the installation surface of the image forming apparatus and in each of the four directions of the image forming apparatus). It is preferable to arrange at least one of the third sheet metal) and electrically connect them to each other.

Further, as shown in FIGS. 4 and 5, the image signal lines 150 and 151 connecting the connector portion 140 provided on the circuit board 100 and the laser scanner 3 are a stay 17 configured as a shield plate and a sheet metal. 18 and the sheet metal 52 are arranged near the outside. As a result, it is possible to suppress the influence of 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 on the image signal lines 150 and 151. This makes it possible to protect the laser scanner 3 from electromagnetic noise.

<Comparison example>
Next, the configuration of the image forming apparatus of the comparative example will be described with reference to FIGS. 9 and 10. FIG. 9 is a cross-sectional explanatory view showing the configuration of the main body A of the image forming apparatus of the comparative example. FIG. 10 is a perspective explanatory view showing a 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 transport guide 14 constituting the transport path R. Further, in the main body A of the image forming apparatus of the comparative example, the plane (fixing surface) of the stay 17 for fixing the laser scanner 3 is provided so as to be parallel to the installation surface of the image forming apparatus.

Further, side plates 15 and 16 arranged to face each other are connected and supported at both ends of the transport guide 14 and the stay 17 in the longitudinal direction. The drive unit 50 is arranged on the outside of the side plate 15, and the circuit board 100 is arranged on the outside of 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 project from the substrate surface 100a of the circuit board 100 toward the outside of the main body A of the image forming apparatus. If the circuit board 100 is arranged in this way, 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 of the low-voltage power element unit 110 and the high-voltage power element unit 120 are mounted is mounted on the back side of the main body A of the image forming apparatus and the image forming apparatus. Place it approximately perpendicular to the installation surface. Then, the low-voltage power element unit 110 protruding from the substrate surface 100a of the circuit board 100, the tall power element of the high-voltage power element unit 120, and the like are arranged so as to project in front of the image forming apparatus toward the transport path R side. ..

These power supply elements are housed in the space 19 formed between the transport 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 (horizontal direction in FIG. 1). In comparison with the comparative examples shown in FIGS. 9 and 10, in the present embodiment, the miniaturization of the image forming apparatus can be achieved.

Further, according to the present embodiment, even if the resin side plates 15 and 16 are used, it is possible to take measures against electromagnetic noise 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. It should be noted that the same components as those in the first embodiment are designated by the same reference numerals or the same member names even if the reference numerals are different, and the description thereof will be omitted.

The image forming apparatus of 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 of the present embodiment has a configuration in which the stay 17 is arranged 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 fixed and supported on 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 sheets 18, 52 and stay 17, respectively, are configured to be substantially perpendicular to the installation surface of the main body A of the image forming apparatus and to cover the side surfaces of the main body A of the image forming apparatus in four directions. It has become. As a result, the sheet metal 18, 52 and the stay 17 serve as a shield plate.

Further, in the present embodiment, a stay 17 configured as a shield plate is provided on the outside of the laser scanner 3. Therefore, the image signal lines 150 and 151 are arranged close to the inside of the stay 17. This makes it possible to suppress the influence of electromagnetic noise on the electrical operation of the laser scanner 3.

Further, it is possible to suppress electromagnetic noise from the outside of the image forming apparatus from being shielded by the stay 17 and affecting the electrical operation of a scanner motor (not shown) or a laser substrate provided inside the laser scanner 3. Further, it is possible to block the electromagnetic noise generated from the inside of the laser scanner 3 from spreading to the outside of the image forming apparatus. Other configurations are configured in the same manner as in the first embodiment, and the same effect can be obtained.

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

Claims (6)

An exposure device that exposes the image carrier and
A circuit board arranged approximately perpendicular to the installation surface of the image forming apparatus,
A drive unit that supplies driving force and
Have,
A first sheet metal that has conductivity and supports the exposure apparatus,
A second sheet metal that has conductivity and supports the circuit board,
A third sheet metal that has conductivity and supports the drive unit,
Have,
The first sheet metal and the second sheet metal so as to surround the image carrier are provided on each of at least three side surfaces of the image forming apparatus in a direction substantially perpendicular to the installation surface of the image forming apparatus and in at least three of the four directions of the image forming apparatus. At least one of the third sheet metal is arranged,
The second sheet metal is arranged at a position outside the circuit board and away from the image carrier .
It has a pair of resin side plates that support both ends of the image carrier in the longitudinal direction of the image carrier, and the second sheet metal has a length extending from one side plate to the other side plate in the longitudinal direction. I have
An image forming apparatus characterized in that. An exposure device that exposes the image carrier and
A circuit board arranged approximately perpendicular to the installation surface of the image forming apparatus,
A drive unit that supplies driving force and
Have,
A first sheet metal that has conductivity and supports the exposure apparatus,
A second sheet metal that has conductivity and supports the circuit board,
A third sheet metal that has conductivity and supports the drive unit,
Have,
The first sheet metal and the second sheet metal so as to surround the image carrier are provided on each of at least three side surfaces of the image forming apparatus in a direction substantially perpendicular to the installation surface of the image forming apparatus and in at least three of the four directions of the image forming apparatus. At least one of the third sheet metal is arranged,
The second sheet metal is arranged at a position outside the circuit board and away from the image carrier.
At least one of the connecting 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.
An image forming apparatus characterized in that. The circuit board has a low-voltage power supply element portion that takes in AC power from an external commercial power source and converts it into DC power, and the second sheet metal supports the circuit board so as to cover at least the low-voltage power supply element portion. The image forming apparatus according to claim 1 or 2 , wherein the image forming apparatus is characterized. The image forming apparatus according to any one of claims 1 to 3, wherein the exposure apparatus and the circuit board are arranged substantially in parallel in the main body of the image forming apparatus. One of claims 1 to 4, wherein the first sheet metal, the second sheet metal, and the third sheet metal are electrically connected to each other so as to have the same potential. The image forming apparatus according to the section. The signal line connecting the exposure apparatus and the circuit board shall be arranged close to at least one of the first sheet metal, the second sheet metal, and the third sheet metal. The image forming apparatus according to any one of claims 1 to 5.

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