JP5157151B2 - Electronics - Google Patents

Description

The present invention relates to an electronic equipment.

  Since electronic devices using digital technology have become widely used and radio wave interference is likely to occur due to the emission of higher harmonics of digital signals, efforts to prevent radio wave interference in the electronic device industry in major countries Has been done.

  For example, for the purpose of effective use of radio waves and to suppress the influence on other devices, seeking to reduce the emission of unnecessary radio waves as much as possible, for example, by ITU (International Telecommunication Union) etc. Wireless communication rules have been established for unnecessary emissions. Many digital electronic devices (hereinafter simply referred to as electronic devices) require countermeasures against unnecessary radiation (EMI: / EMS) in order to comply with the regulations.

  For example, in Japan, there are no legal restrictions on EMI except for those that are subject to the Electrical Appliance and Material Control Law, such as television receivers, but voluntary control councils for information technology equipment: VCCI (Voluntary Control Council for Interference by Information Technology Equipment) The standard for the regulation of radio wave interference, etc.) sets the standard, which is the de facto regulation.

  As countermeasures against radio wave interference, EMI (Electro Magnetic Interference) that prevents electromagnetic noise from being generated and EMS (Electro Magnetic Susceptance) that improves noise resistance so as not to cause interference even when electromagnetic noise is received: There are countermeasures against electromagnetic susceptibility or immunity.

  Here, the generation factors of unnecessary radiation are considered to be radiation from the cable and radiation from the substrate. For example, in an electronic device, a high-speed clock signal may be placed on a signal wiring (including both a print pattern and a cable) that transmits data information. In this case, the data information is weak against external noise and easily affected, and may be emitted as radio noise to the outside of the device, which may adversely affect other peripheral devices.

  For this reason, in general electronic equipment, external noise from outside the device is blocked so that it does not reach elements such as cables and circuit boards in the device, and elements such as cables and circuit boards in the device. One of the important issues is whether to reduce the electromagnetic noise generated from the.

  Speaking of the cable, if the circuits constituting each unit such as the signal processing unit and the control unit are connected by a long connection cable such as a wire harness, radio noise is likely to be emitted from the connection cable, and external noise is likely to be received. And the tendency becomes strong, so that the connection cable length becomes long.

  As countermeasures against electromagnetic noise related to this cable, for example, using shielded cables, or using noise reduction parts such as ferrite cores and ferrite beads between cables and on the board to prevent external noise emission and external There is a technique for blocking noise.

  Further, Patent Document 1 proposes an image copying apparatus that can reduce the length of a connection cable and prevent the emission of radio wave noise and the influence of external noise at low cost. The mechanism described in Patent Document 1 is a measure for reducing radio noise by minimizing a harness by connecting electrical boards. For example, an image reading unit, an image writing unit, and a primary signal processing unit for correcting and processing an image signal from the image reading unit are arranged close to each other, and these have a single grounded conductivity. It is designed to be housed in a housing.

Japanese Patent Laid-Open No. 05-199340

  An object of the present invention is to provide a mechanism that can more reliably eliminate the problem of electromagnetic noise caused by a connection cable regardless of the number of board assemblies mounted.

The invention according to claim 1 is provided with an apparatus main body and an opening for accommodating the substrate assembly, and two substrate assemblies attached to the apparatus main body so that a frame ground is taken can be attached and detached. A printed circuit board housing case and two board assemblies mounted on the printed circuit board and having electronic components mounted thereon, wherein the board ground of the printed circuit board is connected to the printed circuit board. Each of the board assemblies is provided with a conductive board chassis electrically connected to the frame ground via a first mechanical contact means and electrically connected to the board ground of the printed circuit board. And at least one substrate chassis of the substrate assemblies adjacent to each other is provided with a protruding contact portion having conductivity, the adjacent substrates The board chassis of the assembly are electrically connected to each other through the protruding contact portion, and the first mechanical contact means is provided between the board chassis and the mounting surface of the board housing case. A contact part having conductivity and elasticity is provided, and the contact part having elasticity is configured to come into contact with the board chassis. From the mounting surface of the board housing case in the two board assemblies, When the substrate assembly is accommodated in the substrate housing case, the mounting surface of the substrate assembly that is disposed apart from the substrate assembly is brought into contact with the contact surface provided on the opening side of the substrate housing case. The electronic device is configured to be pushed toward the camera .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a case where the image forming apparatus is used as an electronic device will be described as an example. However, this is an example, and the target electronic device is not limited to the image forming apparatus. All embodiments described later can be similarly applied to all electronic devices that house circuit board assemblies on which electronic circuits using digital technology are mounted.

<Configuration of image processing system>
FIG. 1 is a diagram showing an overall outline of an image output terminal having a function of an image forming apparatus which is an embodiment of an electronic apparatus according to the present invention. The image output terminal 1 may be used alone, or may be connected to an image input terminal (not shown) to constitute an image processing system or an image forming system.

  An image input terminal (not shown) creates a digital document (hereinafter simply referred to as a document) DOC and performs processing such as editing. For example, a personal computer, a color scanner, a digital camera, a hard disk device, or a magneto-optical disk It may include any number of image input sources, such as a data storage device such as a device or an optical disc device, or even a FAX device.

  Each of the image input terminals incorporates an application program for creating a document DOC. For example, electronic data representing the document DOC prepared on the image input terminal side is described in an image format (for example, JPEG, BMP, PNG, etc.) that can be processed by the image output terminal 1. For example, a document file created on a personal computer is described in a page description language (PDL) that can freely control the enlargement, rotation, deformation, etc. of figures and characters for printing on a printer, for example. Is sent to the image output terminal 1 as the processed data. The image output terminal 1 receiving this PDL data renders the image data for each output unit (each page) before printing, and then outputs the raster data to the image output unit (printer engine unit).

  The image output terminal 1 is an example of an image forming apparatus according to the present invention. For example, the image output terminal 1 is a so-called multifunction machine having a copying function, a page printer function, and a facsimile transmission / reception function, and is configured as a digital printing apparatus. ing.

  The image output terminal 1 is roughly a controller having an image reading unit 10 for reading a document, an image processing function for performing desired image processing on input image data, and a control function for controlling the operation of the entire terminal. The image recording unit 20 and the image output unit 30 that forms and outputs a visible image on a predetermined recording medium based on the image data from the controller unit 20, and the recording from either the built-in paper feed tray 82 or the manual feed tray 83. A paper feed unit 80 that conveys printing paper as a medium to the image output unit 30 is provided.

  Examples of the built-in paper feed tray 82 include A4, B4, and A3 sizes, used paper (reused paper), colored paper, etc. (A4 (normal paper) 82a, B4 (normal paper) 82b, A4 (used paper) 82c three-stage configuration), a plurality of stages are arranged.

  The image output unit 30 includes an image forming unit 32, a duplex copying unit 34, and a paper discharge unit 36. Both are configured to be detachable from the apparatus main body. Here, the image forming unit 32 and the paper discharge unit 36 are indispensable in terms of the apparatus configuration, whereas the duplex copying unit 34 is used to configure the image output terminal 1 so that duplex printing is possible. However, when a single-sided printing machine is used, it is not necessary to install it.

  The controller unit 20 is disposed in a processing substrate assembly (hereinafter referred to as an “electrical circuit board unit”) 24, which is arranged between the image reading unit 10 and the image output unit 30 and includes one or more circuit boards. Is provided.

  The number of electrical board units 24 is not limited to one, and a plurality of electrical board units 24 are configured to be detachable from the board housing case 26 provided in the apparatus main body 1a. The substrate housing case 26 has a size that allows a plurality of electrical substrate units 24 (that is, a plurality of substrate assemblies) to be detachable (accommodable), and is formed of a conductive metal member as a whole. By making a ground connection (grounding) to the frame ground of the apparatus main body 1a, the substrate housing 26 itself is also made the frame ground. The board housing case 26 is a sheet metal having conductivity, and shields all of the electrical board units 24 by shielding the outer peripheral surface thereof. The apparatus main body 1a may also be further enhanced by forming its exterior surface with conductive sheet metal and shielding the periphery of the electrical board unit 24 twice.

  In the figure, as an example, in addition to the main electrical board unit 24a that must be mounted in the apparatus configuration on which the main (main) board is mounted, as the additional board assembly, two additional electrical equipments each including the sub (sub) board are mounted. A total of three electrical board units 24 of the board units 24 b and 24 c are shown mounted in the board housing case 26. In the example shown in the figure, the electrical board unit 24 is configured to be detachably mounted in the board housing case 26, but may be configured to be mounted and detached in a vertical position.

  The image output terminal 1 can be connected to an external device via a connection cable or a network. For example, the connection cable 90 is a personal computer using a CSMA / CD (Carrier Sense Multiple Access with Collision Detection) type LAN (Local Area Network; for example, IEEE 802.3) or a Gigabit (Giga Bit) based LAN (hereinafter collectively referred to as a wired LAN). Connected to an image input terminal.

  Alternatively, it is connected to an image input terminal such as a FAX apparatus via a public switched telephone network (PSTN). Instead of the general subscriber telephone network PSTN, facsimile may be exchanged using ISDN (Integrated Switched Digital Network) or other communication media including the Internet.

  Further, the image output terminal 1 can be connected to, for example, an IEEE (Institute of Electrical and Electronics Engineers, Inc.) 1394 standard device or a USB (Universal Serial Bus) 2.0 standard device. Digital image data can be received from these devices. Alternatively, the image output terminal 1 can be controlled remotely via these devices.

  With such a configuration, as described above, the image output terminal 1 is acquired from an image input terminal such as a personal computer via the connection cable 90 as well as the printing function of the image read by the image reading unit 10, that is, the copying function. A so-called print function for printing an image based on the document data or image file, and a function for printing out based on FAX data or other image data acquired via a telephone line or other communication interface. .

  The image reading unit 10 also has a platen cover function, a document feeder (ADF (automatic document feeder)) 12 having no circulation function for transporting and discharging a document to a reading position on a reading table (platen glass) (not shown), A user interface unit 15 having an operation panel unit 15a for displaying guidance information for using the device, predetermined information processing results, management information, and the like, and an operation key unit 15b for receiving various instruction inputs from the operator to the device; have. A user interface device having a large user interface or a maintenance screen used in place of or together with the operation panel unit 15a and the operation key unit 15b may be provided.

  The image forming unit 32 converts an image represented by the image signal obtained by the image reading unit 10 into an electrophotographic type, a thermal type, a thermal transfer type, an ink jet type, or a similar conventional image forming process, A visible image is formed (printed), that is, copied on plain paper or thermal paper. Therefore, the image forming unit 32 includes a raster output scan-based print engine for operating the image output terminal 1 as a digital printing system, for example.

  In the electrical board unit 24, not only the processing unit for the image output unit 30 (particularly the image processing unit and the control unit) but also the image processing function unit of the controller unit 20 and the entire image output terminal 1 are processed. A circuit is installed. For example, the document feeder 12, which is a resource built in the image output terminal 1, the operation panel unit 15a, an image reading unit (scanner unit) (not shown) of the image reading unit 10, an image forming unit 32, a duplex copying unit 34, paper discharge A circuit for controlling the unit 36 or the paper feed tray 82 is mounted. The electrical board unit 24 is mounted with a semiconductor storage medium and stores, for example, a copy application, a printer application, a facsimile (FAX) application, or a processing program for other applications.

  The image reading unit 10 has a function of an image input terminal. For example, an image on a document is read by irradiating light to the document sent to the reading position by using a full width array of CCD solid-state imaging devices. The red, green and blue analog video signals representing the read image are converted into digital signals and sent to the image processing function unit of the controller unit 20.

  When the reading is completed in this way, the image processing function unit of the controller unit 20 performs black (K), yellow (based on the red, green, and blue image data R, G, and B from the image reading unit 10. Y), magenta (M), and cyan (C) on / off binarized toner signals are obtained, and the respective toner signals are output to the image output unit 30.

  At this time, in synchronization with reading by the image reading unit 10, when a sheet is fed from any of the plurality of paper feed trays 82 to the image output unit 30, the image forming unit 32 of the image output unit 30. Forms a visible image on one side of the paper based on the K, Y, M, and C toner signals sent from the image processing function unit of the controller unit 20.

  The duplex copying unit 34 turns over the sheet on which the image is formed on one side, and feeds the sheet to the image forming unit 32 again. As a result, the image read by the image reading unit 10 is formed on the other side of the sheet, and double-sided copying is completed.

  The paper discharged from the image forming unit 32 or the double-sided copied paper is sorted sequentially or page by page by the paper discharge unit 36.

  Here, in the image output terminal 1 of the present embodiment, as will be described in detail later, it is possible to cope with electromagnetic noise of the printed circuit board itself in a state where electronic circuit components are mounted, and to ground which is an electrical reference point of the apparatus body. Electrical ground connection (GND; hereinafter also referred to as substrate ground), which is an electrical reference point of each electrical board unit 24, to each (so-called frame ground) and each electrical board unit 24 are made of metal. Adopts electromagnetic radiation countermeasures (radio wave noise countermeasures) combined with a mechanical shield surrounded by a frame.

  Regarding the electrical ground connection, the board ground and the frame ground are mechanically contacted (connected) without using a connection cable (in the figure, schematically shown on both sides of the electrical board unit 24 and the board housing case 26. (Shown by the mechanical contact means 27 provided between the two) to be electrically connected firmly. The mechanical contact means 27 is an example of a first mechanical contact means.

  In addition, a metal plate (sheet metal; hereinafter also referred to as a board chassis) that covers the entire surface of the printed circuit board of each electrical board unit 24 connected to the board ground of each electrical board unit 24 is provided. It may function as a frame ground for the other electrical board unit 24.

  In addition, when each electrical board unit 24 is mechanically fixed to the board housing case 26, a mechanical connection mechanism without using a connection cable (in FIG. 24, the substrate grounds of the adjacent electrical board units 24 (which may be frame grounds using a board chassis) are also electrically strong. Make it connected. The mechanical contact means 28 is an example of a second mechanical contact means.

  That is, when an electrical board unit 24 to be stored in the board housing case 26 is added, the additional electrical board units 24b, 24c,... In addition, the substrate grounds of the other electrical board units 24 adjacent to each other are connected to each other and grounded by using the mechanical contact means 28 as a member for electrical connection. It is.

  First, a plurality of electrical circuit board units 24 are configured to be stored in the same substrate storage housing 26, and even when a single unit is stored, even when a plurality is stored for the purpose of function addition or function expansion, The ground connection of the same mechanical system is performed.

  In the mechanism described in Patent Document 1, an electrical board is accommodated in a board housing case, and the wiring harness is shortened by connecting the electrical boards to prevent radio noise. It is not considered to install an additional electrical board unit for options. As a result, when an electrical board unit is to be added by adding a function or the like, the additional electrical board unit may have to be mounted in a place different from the place where the normal electrical board unit is disposed.

  In this case, the mounted electrical board unit and the additional electrical board unit are relatively separated from each other, and it is difficult to take measures against radio noise by shortening the harness by connecting the boards. Then, when an electrical board unit is added by adding a function or the like, the board ground is connected to a frame ground different from that before the addition, and problems such as radio noise are reproduced.

  In consideration of this point, in the structure of this embodiment, when additional electrical board units 24b, 24c,... Are added by function addition or function expansion, radio noise is caused by being connected to a frame ground different from that before the addition. This eliminates the phenomenon that causes problems.

  As for mechanical shielding, each electrical board unit 24 is housed in the board housing case 26 and is mechanically fixed to the board housing case 26 using a fixing member such as a screw. A countermeasure is taken by covering the periphery of the unit 24 with a metal frame (sheet metal) constituting the substrate housing 26. The frame ground of the board housing case 26 is connected to the frame ground of the apparatus main body electrically and firmly using a mechanical connection mechanism without using a connection cable.

  At this time, using a mechanical connection mechanism (schematically shown by the mechanical contact means 29 in the figure) between the metal plates constituting the substrate housing case 26 without using a connection cable, The frame grounds of each sheet metal are electrically connected to each other. The mechanical contact means 29 is an example of a third mechanical contact means.

  That is, all the electrical board units 24 are shielded by a conductive casing. Due to the shielding effect by the housing, the resistance to external electromagnetic noise is improved, and the radiation of electromagnetic noise emitted from the printed circuit board assembly included in the electrical board unit 24 to the external device is improved (improvement of the blocking effect).

  In addition, since the plurality of electrical board units 24 are configured to be detachable in one housing, the plurality of electrical board units 24 can be collectively accommodated in one place. The cost can be reduced and the assemblability of each electrical board unit 24 can be improved as compared to the case of using a shield structure surrounding the periphery.

  Hereinafter, a mechanism for suppressing electromagnetic radiation in the image output terminal 1 of the present embodiment will be specifically described.

<Accommodation of electrical board unit in board housing>
FIG. 2 is a perspective view showing an outline of the arrangement relationship when only the main electrical board unit 24a is accommodated in the board housing case 26. FIG. FIG. 3 is a perspective view showing an outline of the arrangement relationship when the main electrical board unit 24 a and the additional electrical board unit 24 b are housed in the board housing case 26. FIG. 3A is a diagram showing an outline of a backplane substrate that performs inter-substrate connection.

  FIG. 4 is a front view showing an aspect when each electrical board unit 24 is housed in the board housing case 26. FIG. 5 is a view showing a back surface portion of the board housing case 26 when only the main electrical board unit 24 a is housed in the board housing case 26. FIG. 6 is a view showing a back surface portion of the board housing case 26 when the main board unit 24a and the additional board unit 24b are housed in the board housing case 26. FIG.

  2 and 3, the substantially rectangular parallelepiped substrate housing case 26 in which each electrical board unit 24 is housed has a generally box-like shape with the top (upper surface side) and the front (front surface side) opened. The frame body 26a is formed of a conductive metal plate, and the top frame 26TP is formed of a conductive metal plate that can be attached to and detached from the top of the frame body 26a.

  The bottom frame 26BT, which is the bottom surface of each surface of the frame body 26a, functions as a mounting surface for mounting each electrical board unit 24.

  The top frame 26TP is screwed into a screw hole (both not shown) provided in the upper end portion of the frame body 26a through a screw opening. As a result, regarding the opening on the top (upper surface) side of the substrate housing case 26, an electrical ground connection (ground connection as the mechanical contact means 29) for mechanical shielding and frame grounding is provided. However, this is common regardless of the number of electrical board units 24 accommodated.

  2 and 3, the main electrical board unit 24a is housed from the housing opening on the front side of the frame body 26a constituting the substrate housing 26. With respect to the additional electrical board unit 24b, the top frame 26TP can be detached and attached, or can be attached from the housing opening.

  First, the main electrical board unit 24a includes a board chassis 220 formed of a conductive metal plate and a front panel formed of a conductive metal plate on a board assembly in which electronic components are mounted on the printed circuit board 210. 230 is attached. 2 is the front panel 230a and FIG. 3 is the front panel 230b, but the front panel 230 is used unless otherwise specified.

  The board chassis 220 is screwed to the printed board 210 at appropriate locations near the four corners and the sides. A conductive pattern (not shown) for ground connection is formed on the printed circuit board 210 side to be screwed to the board chassis 220, and mechanical contact between the board ground of the printed circuit board 210 and the board chassis 220 by screwing. The ground connection as the means 27 is taken.

  By providing the board chassis 220 so as to cover substantially the entire surface of the printed board 210, the board chassis 220 can function as a shield member for the printed board 210. The shielding effect against electromagnetic noise emitted from the printed board 210 to the board chassis 220 is improved.

  Although not shown, an end of the board chassis 220 on the front panel 230 side is provided with an L-shaped angle, and a screw hole is provided on a surface of the angle that contacts the front panel 230. By being screwed into the screw hole through the opening, an electrical ground connection (ground connection as the mechanical contact means 27) is established with the front panel 230.

  Thus, when the main electrical board unit 24a is housed and fixed in the board housing case 26, the front panel 230 is electrically connected to the frame ground of the frame body 26a and is connected to the front panel 230 by screws. The board chassis 220 has a frame ground function.

  As a result, as one aspect of the electrical ground connection of the main electrical board unit 24a, the board ground of the printed board 210 is connected to the frame ground of the frame body 26a via the front panel 230 and the board chassis 220. become. In effect, the board chassis 220 has a function of securing a frame ground.

  On the printed circuit board 210 of the main electrical board unit 24a, as electronic components, for example, a main memory, a ROM (Read Only Memory) that is a data read-only memory, a hard disk device (HDD), a connector 212 for supplying power, Electronic circuit components such as a connector 213 for signal connection and other CPUs (Central Processing Units) and ICs (Integrated Circuits) are mounted. A heat sink for heat dissipation is attached to some electronic circuit components having a large heat generation amount such as a CPU.

  The power supply connector 212 and the signal connection connector 213 are provided at the edge of the printed circuit board 210 opposite to the front panel 230. As shown in FIGS. Are connected to the corresponding power supply connector 392 and signal connection connector 393 on the backplane substrate 390 provided on the back side (back frame 26BK side).

  Each connector 212, 213, 392, 393 is not a so-called wiring-to-board connector using a wire harness, but directly connects corresponding connectors, that is, a so-called board capable of fitting corresponding connectors together. This is a connector for board.

  In addition, a sub board (PCI connection board) for mounting a sub board (PCI board) conforming to the PCI (Peripheral Component Interconnect) standard is mounted on the printed circuit board 210, and via a connection connector on the PCI connection board. The PCI board can be mounted.

  In the embodiment shown in FIG. 2 in which only the main electrical board unit 24a is housed in the board housing case 26, either the left or right side portion of the bottom frame 26BT in the board housing case 26 (in the figure, the frame body 26a). On the left end portion 26FL side, an attaching / detaching guide 350 is screwed to the bottom frame 26BT at an appropriate location.

  The attachment / detachment guide 350 is in contact with the side portion of the board chassis 220 of the main electrical board unit 24a, thereby providing a slide guide and positioning function when the main electrical board unit 24a is attached to and detached from the board housing case 26. For example, it is preferable to use an L-shaped angle material.

  On the other hand, in the embodiment shown in FIG. 3 in which the plurality of electrical board units 24 are accommodated in the substrate housing case 26, the bottom frame 26BT in the substrate housing case 26 is substantially replaced with the detachable guide 350. At the center, a bottom chassis 354 is screwed to the bottom frame 26BT at appropriate locations near its four corners and sides.

  By providing the bottom chassis 354 so as to cover substantially the entire surface of the printed board 310 when the additional electrical board unit 24b is attached, the bottom chassis 354 can function as a shield member for the printed board 310. The bottom chassis 354 also functions as a board chassis provided on the side opposite to the board chassis 320. The shielding effect against electromagnetic noise emitted from the printed circuit board 310 to the bottom chassis 354 side is improved.

  As described above, if the bottom chassis 354 is first attached to the bottom frame 26BT, the main electrical board unit 24a can be accommodated and fixed first, and then the additional electrical board unit 24b can be accommodated. In this case, the main electrical board unit 24a can be regarded as a fixed side, and the additional electrical board unit 24b can be regarded as a moving side.

  The additional electrical board unit 24b may be configured to include the bottom chassis 354 in advance, and the bottom chassis 354 of the additional electrical board unit 24b including the bottom chassis 354 and the bottom frame 26BT may be screwed. The bottom chassis 354 also functions as a board chassis provided on the side opposite to the board chassis 320.

  In this case, the bottom chassis 354 has a function of supporting and fixing the printed circuit board 310 in addition to a function of a frame ground. For example, when the additional electrical board unit 24b is placed on an appropriate mounting table (for example, a floor or a work table) outside the apparatus main body 1a, the additional electrical board unit 24b has a shape that can be placed in a stable posture with respect to the mounting table. It also has a function as a supporting member for mounting.

  The left side and the right side of the bottom chassis 354 include a side end attaching / detaching guide (slide guide) function when the main electrical circuit board unit 24a is attached to and detached from the board housing case 26, and a retaining function (prevention of dropping when attaching / detaching). For example, it has a predetermined angle shape so as to perform a positioning function.

  2 and 3, the elastic support members 360 made of conductive metal are provided on the left side and the right side of the bottom frame 26BT from the opening side to the back side (back side). Several frames are provided in a row toward the frame 26BK side.

  The elastic support member 360 may be any elastic member as long as it has elasticity and the surface opposite to the mounting surface with the bottom frame 26BT is a sliding surface with other members. It is preferable to use a spring. The elastic support member 360 is also configured to have electrical conductivity and to be electrically connected to a member formed of another conductive metal placed on the sliding surface. ing.

  2, one elastic support member 360 is arranged on each of the left and right sides on the opening side of the substrate storage housing 26, and the back side (back frame 26BK) in the substrate storage housing 26 is provided. Also, one elastic support member 360 is provided on each of the left and right side sides.

  3, the elastic support member 360 is provided between the left end portion 26FL of the frame body 26a of the bottom chassis 354 and between the right side of the bottom chassis 354 and the right end portion 26FR of the frame body 26a. The figure shows a state in which one elastic support member 360 is arranged on each of the left and right sides on the opening side of the substrate storage housing 26, but the back side (back frame) in the substrate storage housing 26 is shown. 26BK side) is also provided with an elastic support member 360 (not shown).

  Further, the opening side of the bottom frame 26BT of the frame body 26a is a C-shaped reinforcing frame 26FB so that the bottom frame 26BT has a reinforcing function to prevent the bottom frame 26BT from being bent even when the main electrical board unit 24a is inserted. Has been.

  In the embodiment shown in FIG. 3 in which a plurality of electrical board units 24 are housed in the board housing case 26, additional electrical equipment is provided on the bottom frame 26BT (specifically, on the bottom chassis 354) in the board housing case 26. The substrate unit 24b is fixed.

  In the configuration of this embodiment, the main electrical board unit 24a is inserted into the board housing case 26 with the additional electrical board unit 24b mounted in the board housing case 26 in advance (details will be described later). ) A plurality of electrical board units 24a and 24b are mounted in the board housing case 26. However, such a mounting mode is merely an example, and as long as the ground connection corresponding to electromagnetic radiation suppression described later is maintained, other methods are adopted, and a plurality of electrical board units 24 are installed in the board housing case 26. May be installed.

  In any mounting form, the electrical board unit 24 in the board housing case 26 is arranged in the vertical direction in order to avoid the influence of heat generation. It is preferable to dispose an electrical board unit 24 having a large calorific value (in this example, the main electrical board unit 24a) on (in this example, other than the main electrical board unit 24a).

  In the additional electrical board unit 24b, first, a board chassis 320 formed of a conductive metal plate having substantially the same area and shape as the printed board 310 is mounted on a board assembly in which electronic components are mounted on the printed board 310. The printed circuit board 310 is attached so as to cover almost the entire surface. The board chassis 320 is screwed to the printed board 310 at appropriate locations near the four corners and the sides.

  By providing the board chassis 320 so as to cover substantially the entire surface of the printed board 310, the board chassis 320 can function as a shield member for the printed board 310. The shielding effect against electromagnetic noise emitted from the printed board 310 to the board chassis 320 is improved.

  On the printed circuit board 310 of the additional electrical board unit 24b, although not shown, for example, an electronic circuit component such as a connector 312 that serves both as a power supply and a signal connection and an IC is mounted as an electronic component. Has been.

  A connector 312 serving both for power supply and signal connection is provided at the edge of the printed circuit board 310 opposite to the opening of the board housing case 26. As shown in FIG. 26 is connected to a corresponding connector 394 serving both as a power supply and a signal connection on a backplane substrate 390 provided on the back side (back frame 26BK side).

  Each connector 212, 213, 312, 392, 393, 394 is not a so-called wiring-to-board connector using a wire harness, but directly connects corresponding connectors, that is, fits the corresponding connectors together. This is a so-called board-to-board connector.

  The same wirings on the printed circuit boards 210 and 310 of the electrical circuit board units 24a and 24b are connected to the connectors provided on the printed circuit boards 210 and 310 of the electrical circuit board units 24a and 24b without using a connection cable, and the relay circuit board. The connectors are directly connected to each other using a connector provided on the backplane substrate 390 as an example.

  When connecting between boards with a connection cable such as a wire harness, electromagnetic noise such as emission from the connection cable and reception of external electromagnetic noise becomes a problem, but by using the backplane board 390 as a relay board, In addition to minimizing the flow of signals between the boards of the electrical board unit 24, the resistance to electromagnetic noise associated with the connection between boards is improved and the amount of emission is reduced.

  As shown in FIG. 3A or FIG. 5 and FIG. 6, the backplane board 390 is provided with an output control connector 396 (not limited to one but may be plural). A board-to-board type board-to-board connector for a board unit for controlling the image forming unit 32 (not shown) located below the board is connected.

  In addition, when connecting the boards to accommodate the plurality of electrical board units 24 in the board housing case 26 and connect the wiring of each board, without using the backplane board 390 and the connector on the backplane board 390, It is also conceivable to adopt a mechanism for directly fitting the connectors on each electrical board unit 24 together.

  For example, as shown in FIG. 6C, the power supply connector 212 and the signal connection connector 213 of the main electrical board unit 24a are placed at appropriate positions on the surface of the printed circuit board 210 on the side of the additional electrical board unit 24b. The power supply connector 312 and the signal connection connector 313 are provided at corresponding positions on the main electrical board unit 24a side of the additional electrical board unit 24b after assembly, and the corresponding connectors are directly fitted to each other. Let

  However, such a mechanism imposes restrictions on the distance between the substrates, the direction of movement when the one substrate (in this example, the main electrical board unit 24a) is attached to or detached from the substrate housing 26, and the connector. Since the moving direction for connecting each other is orthogonal, detachability and assemblability are lowered. When the number of accommodation is two, it can be adopted. However, when the number of accommodation is increased, inconvenience that the mounting and dismounting and assembling of the electrical board unit 24 becomes particularly difficult is considered.

  A conductive pattern (not shown) for ground connection is formed on the printed circuit board 310 side that is screwed to the board chassis 320, and the board ground of the board chassis 320 and the printed circuit board 310 and the frame body 26a are fixed by screwing. A ground connection is provided as a mechanical contact means 27 with the frame ground.

  As a result, as one aspect of the electrical ground connection of the additional electrical board unit 24b, the board ground of the printed board 310 is connected to the frame ground by being screwed with the printed board 310 interposed therebetween. In addition, the board chassis 320 has not only a board fixing function but also a frame ground function.

  Further, since the board chassis 320 is formed so as to cover substantially the entire surface of the printed board 310, when the main electrical board unit 24a is inserted and mounted on the board chassis 320 in the board housing case 26, It also has a function of protecting electronic circuit components on the printed circuit board 310.

  Also, a conductive contact portion 326 having conductivity is provided in the vicinity of the board chassis 320 with the printed circuit board 310 and screws. As the protrusion contact portion 326, for example, the substrate chassis 320 may be formed into a round convex shape by drawing, or a protrusion contact that is separately formed so as to be hemispherical with a conductive member. The planar portion of the portion 326 may be connected to the board chassis 320 by welding or the like.

  Further, in FIG. 3 in which a plurality of electrical board units 24 are stacked in a layered structure, that is, stacked in the board housing case 26, the board of the main electrical board unit 24a disposed away from the bottom frame 26BT. The chassis 220 has a conductive bracket (Bracket) 224 that provides an electrical ground connection between the frame ground of the bottom frame 26BT and the board chassis 220 (here, a ground connection as the mechanical contact means 27). It is attached as a relay member or support member for taking.

  The length, shape, etc. of the bracket 224 are appropriate according to the thickness and the number of other electrical board units 24 to be arranged between the bottom frame 26BT (in this example, only one additional board unit 24b). What is necessary is just to set suitably.

  In the present embodiment, the bracket 224 can be attached to and detached from the board chassis 220 by screwing or the like, and is additionally attached only when the additional electrical board unit 24b is mounted.

  The bracket 224 is mounted on the board chassis 220 so that the bracket 224 moves on the elastic support member 360 attached to the bottom frame 26BT when the main electrical board unit 24a is housed in the board housing case 26. The elastic support member 360 is attached to an appropriate position.

  Although details will be described later, the side of the bracket 224 on the side of the bottom chassis 354 is predetermined so as to correspond to the side end attaching / detaching guides formed on both side ends of the bottom chassis 354 and the angle shape that functions for retaining and positioning. It is an angle shape. Thus, the side end when the main electrical board unit 24a, which is the electrical board assembly on the side to be attached and detached, is attached to and detached from the board housing case 26 by the combination with the angle shape provided at the left and right side edges of the bottom chassis 354. It is designed to function as an attachment / detachment guide (slide guide), retaining (preventing dropping) and positioning.

  The bracket 224 provided on the board chassis 220 of the main electric board unit 24a which is the electric board assembly to be attached / detached is attached to the main electric board when the additional electric board unit 24b which is the optional board assembly is attached to the board housing case 26. When the unit 24a is removed (separated) from the substrate housing case 26 and placed on an appropriate mounting table (for example, a floor or a work table) outside the apparatus main body 1a, the main electrical board unit 24a is stabilized with respect to the mounting table. It has a shape that can be placed in a posture, and also has a function as a support member for placement.

  Here, in electronic devices such as the image output terminal 1, countermeasures against electromagnetic noise are indispensable. Also in the image output terminal 1, in order to suppress the amount of electromagnetic waves directly radiated from the image output terminal 1, First, means for suppressing unnecessary electromagnetic noise emission, that is, unnecessary radiation noise, is taken from the side surface of the printed circuit board itself with electronic circuit components mounted thereon.

  Causes of unwanted radiation include normal mode noise radiation from a printed circuit board that can be considered with a loop antenna model, and common from a connection cable such as a wire harness that can be considered with a dipole antenna model.・ It can be roughly divided into mode noise emission.

  With regard to the electromagnetic radiation suppression when accommodating the electrical board unit 24 in the board housing case 26, the printed board itself is improved with respect to radiation from the printed board, and each of the electrical board units 24 and the board housing case is further improved. A ground connection between the substrate ground and the frame ground is established with the body 26 by mechanical contact means 27 using various mechanisms. In addition, when a plurality of electrical board units 24 are mounted on the board housing case 26, the board grounds or one board ground and the other board ground are connected between the electrical board units 24 by the mechanical contact means 28. A ground connection is made to the board chassis having a frame ground function. In principle, radiation from the connection cable is eliminated by using the mechanical contact means 27 and 28 to connect to the ground without using a connection cable such as a wire harness.

  Measures from the aspect of normal mode noise are taken as countermeasures for suppressing electromagnetic radiation of the printed circuit board itself. That is, the electronic circuit on the printed circuit board is configured by a combination of a circuit connected from the output side to the load side and a circuit returning from the load side. When a noise current flows through such a loop circuit, the loop circuit functions as a loop antenna, and thereby electromagnetic noise (radio waves) is emitted.

  The output of this electromagnetic noise is proportional to the square of the loop area and the loop current. Therefore, in order to reduce the output of noise radio waves, 1) reduction of the loop area from the side of the printed pattern, 2) reduction of the noise current loop area using a noise removal capacitor such as a bypass capacitor, 3) resistance and It is effective to limit the current with an inductor (coil). In any case, it is possible to take measures against radiation from the printed circuit board from the aspects of circuit design using printed circuit board pattern design and noise countermeasure components.

  First, the front panel 230 is provided with openings for the external IF connector 214 (four locations in the figure) attached to the main electrical board unit 24a and for the PCI board. The three external IF connectors 214a, 214b, 214c and the PCI board are fastened to the front panel 230 by screws.

  The upper end side 230TP of the front panel 230 is slightly bent outward, and the conductive property for making an electrical connection with the substrate storage case 26 is provided on the substrate storage case 26 side of the upper end side 230TP. An elastic connecting member 232 having the above is provided. In addition, screw openings 234 for attachment to the substrate storage housing 26 are provided at the left end and the right end of the front panel 230.

  Further, as shown in FIG. 4 (front view), in both of the front panels 230a and 230b, a conductive protrusion contact portion 236 is predetermined on the lower end side 230BT on the bottom frame 26BT side of the substrate housing 26. Arranged at pitch. The arrangement pitch of the protrusion contact parts 236 is set to an appropriate value according to the frequency of the electromagnetic wave radiated to the outside from the inside of the board housing case 26 containing the electrical board unit 24, for example, 80 mm.

  As the protrusion contact portion 236, for example, the metal plate of the lower end side 230BT may be formed into a round convex shape by drawing, or separately formed so as to be hemispherical with a conductive member. The planar portion of the protruding contact portion 236 may be connected to the lower end side 230BT by welding or the like.

  Here, as the front panel 230, there are a mode shown in FIG. 2 in which only the main electrical board unit 24a is mounted and a mode shown in FIG. 3 in which the additional electrical board unit 24b can also be mounted. The front panels 230a and 230b having different shapes are used. The major difference between the front panels 230a and 230b is that, in the embodiment shown in FIG. 3, the front panel 230b is provided with an opening 238 (one place in the figure) for the external IF connector 314 attached to the additional electrical board unit 24b. It is a point.

  In other respects, the attachment positions of the external IF connectors 214 (four locations in the figure) attached to the main electrical board unit 24a are slightly different. In the illustrated example, the attachment positions of the external IF connectors attached to the main electrical board unit 24a are different in FIGS. 2 and 3, but they may be exactly the same.

  A cooling fan 26 </ b> FAN is attached to the top frame 26 </ b> TP of the substrate storage housing 26 to cool internal members by causing convection (air flow) in the substrate storage housing 26. The direction of air flow of the cooling fan 26FAN is, for example, the direction in which the internal air is discharged to the outside as shown in the upper left portion of FIG. However, this is only an example, and conversely, the direction in which external air is taken in may be used.

  In any case, in order to avoid the influence of heat generation, when a plurality of electrical board units 24 are accommodated in the board housing case 26, a main heat generation quantity with a small heat generation amount is placed under the main electrical circuit board unit 24a with a large heat generation quantity. An additional electrical board unit 24b other than the electrical board unit 24a is arranged. In the main electrical board unit 24a having a large calorific value, an electronic component having a particularly large calorific value dissipates heat with a heat sink. Cooling is performed by an air flow by a cooling fan 26FAN provided in the frame 26TP.

  When the main electrical board unit 24a is attached to the end of the top frame 26TP on the opening side, a contact surface for electrical connection with the elastic connection member 220 on the main electrical board unit 24a side 26CS is provided.

  The left end portion 26FL and the right end portion 26FR on the opening side of the frame body 26a have an L-shaped angle shape, and the main electrical equipment is located at a position corresponding to the screw opening 234 of a part of the main electrical equipment board unit 24a on the angle surface. A screw hole 26K for attaching the substrate unit 24a is provided. The main electrical board unit 24a is screwed into the screw holes 26K provided in the end portions 26FL and 26FR of the frame body 26a through the screw openings 234 of the front panel 230. As a result, regarding the opening of the substrate housing case 26, an electrical ground connection (ground connection as the mechanical contact means 29) for taking a mechanical shield and taking a frame ground is used as the electrical board unit 24. It is taken in common regardless of the number.

  In the present embodiment, the front panel 230 is screwed to the board chassis 220 so as to be handled integrally with the main electrical board unit 24a. However, this is not essential, and the front panel 230 is used as the main electrical board unit. The main electrical board unit 24a may be housed in the frame body 26a and then screwed to the board chassis 220 or the frame body 26a. However, as in the present embodiment, handling the front panel 230 integrally with the main electrical board unit 24a makes it easier to handle (manage) the components and improve the assemblability.

  Regardless of whether the front panel 230 is integrated with or separate from the main electrical board unit 24a, when the front panel 230 is attached to the frame body 26a, in addition to the above-described ground connection by screwing, the upper end of the front panel 230 The elastic connecting member 232 provided on the side 230TP and the contact surface 26CS provided on the case opening side of the top frame 26TP of the substrate storage case 26 come into contact with each other, An electrical ground connection (ground connection as the mechanical contact means 29) for taking a mechanical shield of the substrate housing case 26 and a frame ground (ground connection as the mechanical contact means 29) is made common regardless of the number of electrical board units 24 accommodated.

  Furthermore, as shown in FIG. 4 (front view), a bottom having a structure of a plurality of conductive protrusion contact portions 236 provided on the lower end side 230BT of the front panel 230 and a reinforcing frame 26FB of the substrate storage housing 26. When the frame 26BT comes into contact with the opening of the substrate housing case 26, an electrical ground connection (grounding as the mechanical contact means 29) is provided for mechanical shielding of the substrate housing case 26 and frame ground. Connection) is commonly used regardless of the number of electrical board units 24 accommodated.

<Configuration example of elastic connecting material>
FIG. 7 is a view showing a configuration example of the elastic connecting member 232 provided on the upper end side 230TP of the front panel 230. As shown in FIG.

  As shown in FIGS. 7A and 7B, the elastic connecting member 232 is formed by winding an elastic member such as a long sponge with a conductive cloth-like exterior tape on one of the long surfaces. Along the longitudinal direction, an adhesive member such as a conductive double-sided tape is attached. When a sponge is used as the elastic member, it is referred to as a sponge-like gasket (GASKET).

  As shown in FIG. 7C, the elastic connecting member 232 having such a structure is bent slightly outward by using an adhesive member such as a double-sided tape having conductivity. Affixed to the substrate housing case 26 side.

<Front sectional view>
FIG. 8 is a cross-sectional view seen from the front side showing an aspect when only the main electrical board unit 24a is housed in the board housing case 26. FIG.

  As shown in FIGS. 8A and 8D, a detachable guide 350 using an L-shaped angle member is provided on the left end portion 26FL side of the frame body 26a of the bottom frame 26BT.

  As shown in FIG. 8B, the attaching / detaching guide 350 may be provided not only on the left end portion 26FL side of the bottom frame 26BT but also on the right end portion 26FR side. In this case, both sides of the board chassis 220 indicated by dotted lines in the figure are arranged so as to be sandwiched with a slight gap (for example, about 2 to 5 mm) with respect to the side of the board chassis 220. Thereby, the movement of the main electrical board unit 24a in the left-right direction is restricted, and the main electrical board unit 24a is prevented from being completely separated from the left and right sides. The attachment / detachment guide 350 has a function of retaining the main electrical board unit 24a to the left and right sides and roughly positioning in the left and right direction.

  Further, the structure of the attaching / detaching guide 350 is not limited to the L-shaped angle member, and may be a channel member having a C-shaped cross section as shown in FIG. 8C, for example. In this case, both side portions (sides and their upper and lower surfaces) of the board chassis 220 indicated by dotted lines in the drawing are slightly smaller than both side portions (sides and their upper and lower surfaces) of the board chassis 220 (for example, It is arranged so that it can be sandwiched with a gap (about 2 to 5 mm). As a result, the movement of the main electrical board unit 24a in the left-right direction and the vertical direction is restricted, and the main electrical board unit 24a is prevented from being detached to the upper side and the left-right side.

  Regarding the vertical direction, the height restriction h1 of the board chassis 220 from the bottom frame 26BT is made smaller than the normal length L1 of the elastic support member 360, so that the height of the board chassis 220 from the bottom frame 26BT can be increased. It is regulated to h1. The attachment / detachment guide 350 has functions of retaining the main electrical board unit 24a on the upper side and the left and right sides, and roughly positioning the main electrical board unit 24a in the vertical and horizontal directions.

  As shown in FIG. 8D, the bottom surface of the substrate chassis 220 contacts the sliding surface 360a of the elastic support member 360 provided on the bottom frame 26BT, and pushes the elastic support member 360 toward the bottom frame 26BT (see FIG. 8D). To be compressed).

  The contact state of the elastic support member 360 with respect to the board chassis 220 is maintained even after the main electrical board unit 24a is housed and fixed in the board housing case 26, and is electrically connected to the frame body 26a. (Ground connection as the mechanical contact means 27) is taken. As a result, the frame ground of the frame main body 26 a is connected to the board chassis 220 via the elastic support member 360.

  As described above, the board chassis 220 is connected to the board ground of the printed board 210. Therefore, as a result, as one aspect of the electrical ground connection of the main electrical board unit 24a, the board ground of the printed circuit board 210 is connected to the frame ground of the frame body 26a via the elastic support member 360 and the board chassis 220. Will be.

  Further, as shown in FIG. 8D, when the main electrical board unit 24 a is housed in the board housing case 26, the left side of the board chassis 220 can be pushed along the attachment / detachment guide 350. At this time, the side portion of the board chassis 220 can be repeatedly contacted / non-contacted with the attaching / detaching guide 350, but the movement of the main electrical board unit 24 a in the left-right direction is restricted by contacting the attaching / detaching guide 350. The attachment / detachment guide 350 has a function of a slide guide, and also has a function of retaining the main electrical board unit 24a to the left and right sides and a rough positioning function in the left and right direction. Of course, the effect is enhanced when the detachable guides 350 are arranged on both sides.

  On the other hand, after the main electrical board unit 24a is housed and fixed in the board housing case 26, the state in which the board chassis 220 can be brought into contact with the attachment / detachment guide 350 is released, and the non-contact state is maintained. In addition, it is preferable to arrange them at positions where they do not contact each other.

  This means that the frame ground of the frame main body 26a and the substrate ground of the printed circuit board 210 are not connected in a form that is difficult to handle as a stable connection state.

  The main electrical circuit board unit 24a can be maintained in a non-contact state with the board chassis 220 so that the shape part forming the attachment / detachment guide 350, the shape part preventing the drop-off, and the shape part positioning can be maintained in the non-contact state. It should be housed and installed in the box.

  That is, after the main electrical board unit 24a is accommodated and fixed in the board housing case 26 while having functions such as an attachment / detachment guide, drop-off prevention and positioning when the main electrical board unit 24a to be attached / detached is mounted, The shape of the attachment / detachment guide 350 is set so that the substrate chassis 220 can be disposed at a position where it is not electrically connected to the attachment / detachment guide 350.

  Even after the main electrical board unit 24a is fixed to the frame body 26a, in a state where the board chassis 220 is in contact with the attaching / detaching guide 350 or in a state where it can come into contact with vibration or the like, mechanical ground connection with the frame ground is performed. Becomes unstable, and the noise level and tendency cannot be made the same with respect to radio wave noise, which is greatly different from the problem of electromagnetic noise.

  FIG. 9 is a cross-sectional view seen from the front side showing a mode when a plurality of electrical board units 24 (main electrical board unit 24a and additional electrical board unit 24b) are housed in the board housing case 26. FIG. Here, it is assumed that the additional electrical board unit 24b includes a bottom chassis 354.

  As shown in FIG. 9, the bottom chassis 354 supports and fixes the printed circuit board 310 and the board chassis 320 on which the protrusion contact portions 326 are formed. At this time, the support column 355 is used as necessary. The support column 355 may be formed by cutting out a part of the bottom chassis 354, or a different one may be used.

  When the additional electrical board unit 24b is mounted on the frame body 26a, the bottom chassis 354 is screwed to the bottom frame 26BT of the frame body 26a as shown in FIG. 9A. Thereby, as one aspect of the electrical ground connection of the additional electrical board unit 24b, the frame ground of the frame body 26a is connected to the board ground of the printed circuit board 310 and the board chassis 320 via the bottom chassis 354. . In effect, the bottom chassis 354 has a function of securing a frame ground as well as a function of supporting the board (fixing the board).

  Note that, as indicated by a dotted line in FIG. 9A, a protrusion contact portion 358 constituting the mechanical contact means 27 may be provided on the bottom portion (bottom frame 26BT side) of the bottom chassis 354. In this case, the bottom frame 26BT is brought into contact via the protrusion contact portion 358 provided on the bottom chassis 354, whereby an electrical ground connection between the additional electrical board unit 24b and the frame body 26a (mechanical contact means). 27).

  Since the bottom chassis 354 is provided with the protrusion contact portion 358 so that the bottom chassis 354 and the bottom frame 26BT are brought into contact with each other, the contact position is the arrangement position of the protrusion contact portion 358 of the bottom chassis 354 and is constant. The ground connection system of the frame ground related to the bottom chassis 354 in the assembled state is stable and stable.

  By providing the bottom chassis 354 and the bottom frame 26BT in contact with each other without providing the protrusion contact portion 358 on the bottom chassis 354, a first mechanical connection for connecting the board ground and the frame ground of the printed circuit board. It is also conceivable to constitute a simple contact means. However, in this case, the contact position is in accordance with the unevenness of each surface, and is not necessarily limited to the screwing position and is not constant. For this reason, the electromagnetic noise prevention performance with respect to connecting the bottom chassis 354 as a frame ground and connecting to the board ground of the printed circuit board 310 is inferior to the case where the protrusion contact portion 358 is used.

  As shown in FIG. 9A, the left and right sides of the bottom chassis 354 are provided with predetermined attachment / detachment guides 356 (L-shaped two-stage configuration in the figure). When the additional electrical board unit 24b is attached to the bottom frame 26BT of the frame body 26a, as shown in FIG. 9B, the bottom chassis 354 is disposed substantially at the center of the bottom frame 26BT. In this state, the main electrical board unit 24a is mounted.

  Further, as shown in FIG. 9B, brackets 224 are provided on the left side and the right side of the board chassis 220 on the main electrical board unit 24a side. The board chassis 220 has a side-end attaching / detaching guide (slide guide) function, a retaining function (preventing dropout prevention), and a positioning function when the main electrical board unit 24a is attached to and detached from the board housing case 26. As described above, the bottom chassis 354 has a shape corresponding to the attaching / detaching guide 356, for example, a predetermined angle shape.

  As a result, the combination with the shape of the detachable guide 356 on the bottom chassis 354 side allows the main electrical board unit 24a on the detachable side to be smoothly attached and removed when expanding functions or adding optional electrical components, and maintenance can be performed. The main electrical board unit 24a can be prevented from falling off even at an intermediate position.

  For example, the surface (a surface in the figure) that can come into contact with the inner surface of the attaching / detaching guide 356 is a flat surface, and the bracket 224 is prevented from coming off on the bottom frame 26BT side surface (top surface; c surface in the figure). A guide 228 is provided so as to protrude toward the bottom chassis 354 side.

  For example, when the main electrical board unit 24a is housed in the board housing case 26, there is a slight (for example, 2 to 2) between the inner side surface of the bracket 224 and the left / right direction of the attachment / detachment guide 356 of the bottom chassis 354. Provide a gap (about 5 mm) so that it can be sandwiched. Thereby, first, when the main electrical board unit 24 a is accommodated in the board housing case 26, it can be pushed along the bracket 224 and the attachment / detachment guide 356. The bracket 224, the attaching / detaching guide 356, and the slide guide function.

  That is, in the process of mounting the main electrical circuit board unit 24a, a slight gap is provided between the bracket 224 and the attachment / detachment guide 356 of the bottom chassis 354, but the end of the attachment / detachment guide 356 of the bottom chassis 354 is the bracket 224. It is possible to come into contact with the inner side surface (both surfaces of “a” in the figure). Thereby, the movement of the main electrical board unit 24a in the left-right direction is restricted, and the main electrical board unit 24a is prevented from detaching to the left and right. The bracket 224 and the attachment / detachment guide 356 (specifically, each a surface) have a function of retaining the main electrical board unit 24a to the left and right and a rough positioning in the left and right direction.

  Further, in the process of mounting the main electrical circuit board unit 24a, the bracket 224 is prevented from coming off at the step portion of the mounting / demounting guide 356 of the bottom chassis 354 (both surfaces "b" in the drawing). So as to be able to come into contact with the escape prevention guide 228. Accordingly, the vertical movement of the main electrical board unit 24a is also restricted by the height h2 from the bottom frame 26BT, and the main electrical board unit 24a is prevented from being detached upward. The removal prevention guide 228 and the attachment / detachment guide 356 (specifically, each b surface) have functions of preventing the main electrical board unit 24a from being pulled out upward and positioning in the vertical direction.

  Accordingly, the additional electrical board unit 24b on the side to be fixed and added in the board housing case 26 includes the bottom chassis 354 having the function of fixing the printed circuit board 310 and the frame ground function, and the detachable side disposed at the top. And a detachable guide 356 that constitutes a detachable guide mechanism (detachable guide function) for the main electrical board unit 24a, which is the board assembly of the circuit board assembly, and is in the process of being pulled out of the main electrical board unit 24a to be detached. Even at the position, the main electrical board unit 24a is prevented from dropping or dropping in the vertical and horizontal directions.

  Further, as shown in FIG. 9B, the bottom surface (“c” portion in the figure) of the bracket 224 is in contact with the sliding surface 360a of the elastic support member 360 provided on the bottom frame 26BT, and is elastically supported. The member 360 is pushed (compressed) into the bottom frame 26BT side.

  The contact state of the elastic support member 360 with the bottom surface of the bracket 224 is maintained even after the main electrical board unit 24a is housed and fixed in the board housing case 26, and is electrically grounded with the frame body 26a. Connection (ground connection as mechanical contact means 27) is taken.

  As a result, the frame ground of the frame main body 26 a is connected to the board chassis 220 via the elastic support member 360 and the bracket 224. As described above, the board chassis 220 is connected to the board ground of the printed board 210. Therefore, as a result, as one aspect of the electrical ground connection of the main electrical board unit 24a, the board ground of the printed circuit board 210 is connected to the frame of the frame body 26a via the elastic support member 360, the bracket 224, and the board chassis 220. It will be connected to the ground.

  The additional electrical board unit 24b is already attached to the bottom frame 26BT, the board ground and the frame ground are connected via the bottom chassis 354, and the mechanical contact means 27 for the additional electrical board unit 24b is configured. It is a different system (common but different grounding system as an example of the mechanical contact means 27), and the mechanical contact means via the elastic support member 360 and the bracket 224 for the main electrical board unit 24a. 27 is configured.

  As can be seen from the above description, when the main electrical board unit 24a is housed in the board housing case 26, the detachable guide 356 side of the bracket 224 that is integrally attached to the board chassis 220 becomes the detachable guide 356. Can be pushed along. At this time, the bracket 224 can repeat contact / non-contact with the attachment / detachment guide 356, but the movement of the main electrical board unit 24 a in the left-right direction and the up-down direction is restricted by contacting the attachment / detachment guide 356.

  On the other hand, after the main electrical board unit 24a is housed and fixed in the board housing case 26, the state in which the bracket 224 of the board chassis 220 can be brought into contact with the attaching / detaching guide 356 of the bottom chassis 354 is released. Ensure that contact is maintained. The frame ground of the frame body 26a and the board ground of the printed circuit board 210 are prevented from being connected in a form that is difficult to handle as a stable connection state. After fixing each of the electrical board units 24a and 24b to the board housing case 26, it is preferable to arrange them at positions where they are not grounded.

  Even after the main electrical board unit 24a is fixed to the frame body 26a, the bracket 224 attached to the board chassis 220 can come into contact with the attaching / detaching guide 356 formed on the bottom chassis 354 by vibration or the like. In such a state, the mechanical ground connection with the frame ground becomes unstable, and the noise level and tendency cannot be made the same with respect to radio wave noise, which is greatly different from the problem of electromagnetic noise.

<Side view>
FIG. 10 is a right side cross-sectional view showing an aspect when only the main electrical board unit 24a is housed in the board housing case 26. FIG. FIG. 11 is a right side cross-sectional view showing an aspect when the main electrical board unit 24 a and the additional electrical board unit 24 b are housed in the board housing case 26.

  FIG. 12 is a cross-sectional view of the left side surface showing a mode in which only the main electrical board unit 24a is housed in the board housing case 26. FIG. 13 is a cross-sectional view of the left side focusing on the bracket 224 portion showing an aspect when the main electrical board unit 24a and the additional electrical board unit 24b are housed in the board housing case 26. FIG.

  As shown in FIGS. 10, 11, 12, and 13, the contact surface 26 CS of the top frame 26 TP corresponding to the elastic connecting member 232 attached to the upper end side 230 TP of the front panel 230 is an opening of the frame body 26 a. It is formed by folding the side edge.

  Further, as shown in FIGS. 10, 11, 12, and 13, the end portion of the board chassis 220 on the front panel 230 side is provided with an L-shaped angle 222, and contacts the front panel 230 of the L-shaped angle 222. A screw hole is provided on the surface, and by screwing into the screw hole through the screw opening of the front panel 230, a ground connection for connecting the board ground of the main electrical board unit 24a and the frame ground of the frame body 26a is provided. As one aspect, an electrical ground connection (ground connection as the mechanical contact means 27) is established between the front panel 230 and the frame body 26a.

  Since the front panel 230 and the frame main body 26a are brought into contact with the screw holes of the frame main body 26a through the screw openings of the front panel 230, the contact positions thereof are the screw openings on the front panel 230 and the screw holes of the frame main body 26a. It becomes an arrangement position and becomes constant. The ground connection system of the frame ground between the front panel 230 and the frame body 26a in the assembled state is stable and stable. Of course, the mechanical attachment position of the front panel 230 with respect to the frame main body 26a is also defined by the screw opening and screw hole arrangement positions, so that there is no variation in the assembled state, and it is stable.

  The elastic support members 360 provided on both side sides of the bottom frame 26BT are arranged so that the main electrical equipment board unit 24a is housed in the board housing case 26 and is fixed to the frame body 26a. As one aspect of the electrical ground connection of the board unit 24a, the frame ground of the frame body 26a has a function of connecting to the board ground of the printed circuit board 210 of the main electrical board unit 24a or the board chassis 220 having a frame ground function.

  For example, in a form in which only the main electrical board unit 24a is housed in the board housing case 26, the board chassis 220 of the main electrical board unit 24a directly contacts the elastic support member 360, so that the frame ground of the frame body 26a An electrical ground connection (here, a ground connection as the mechanical contact means 27) is established with the substrate chassis 220.

  For example, as shown in FIG. 12, a predetermined (a substantially L-shaped with a taper) attachment / detachment tip guide 223 is provided at the tip of the board chassis 220 opposite to the front panel 230a side. The bottom surface (“d” portion in the drawing) of the detachable tip guide 223 is in contact with and pushed into an elastic support member 360 provided on the bottom frame 26BT.

  As shown in FIGS. 10 and 12, the back frame 26BK is arranged along a slide guide or a detachable guide 350 which is attached to the bottom frame 26BT in the substrate housing case 26 and has a function of positioning. Pushed into the side.

  At this time, the bottom surface (“d” portion in FIG. 12) of the mounting / dismounting tip guide 223 of the board chassis 220 pushes (compresses) the elastic support member 360 attached to the bottom frame 26BT, and the board chassis 220 It is fed to the back frame 26BK side while sliding on the elastic support member 360.

  Here, when the main electrical board unit 24a is housed in the board housing case 26 and the front panel 230a is screwed to the frame body 26a and the positional relationship between them is fixed, FIGS. 10 and 12 (FIG. 8). As shown in FIG. 5), the elastic support member 360 provided on the bottom frame 26BT of the board housing case 26 comes into contact with the board chassis 220 on the bottom surface side of the printed board 210 of the main electrical board unit 24a. Electrical ground connection (ground connection as the mechanical contact means 27) is established between the main electrical board unit 24a and the board housing case 26.

  On the other hand, when accommodating not only the main electrical board unit 24 a but also the additional electrical board unit 24 b in the board housing case 26, first, the additional electrical board unit 24 b is attached in the board housing case 26.

  As shown in FIG. 13, a predetermined (a substantially L-shaped with a taper) attachment / detachment tip guide 226 is formed at the tip of the bracket 224 opposite to the front panel 230 b side in the longitudinal direction. The bottom surface (“e” portion in the drawing) of the attaching / detaching tip guide 226 of the bracket 224 is in contact with and pushed into an elastic support member 360 provided on the bottom frame 26BT.

  As shown in FIGS. 11 and 13, the additional electrical board unit 24b is provided on the left side and the right side of the bottom chassis 354 attached to the bottom frame 26BT for the board housing case 26 on which the board is mounted. It is pushed into the back frame 26BK along the slide guides and the removal prevention guides 228 and 356 which are configured to function as a retaining and positioning.

  At this time, the bottom surface (“e” portion in FIG. 13) of the attachment / detachment tip guide 226 of the bracket 224 pushes (compresses) the elastic support member 360 attached to the bottom frame 26BT, and the bracket 224 elastically supports it. It is fed to the back frame 26BK side while sliding on the member 360.

  Here, when the main electrical board unit 24a is housed in the board housing case 26 and the front panel 230b is screwed to the frame body 26a and the positional relationship between the two is fixed, FIGS. 11 and 13 (FIG. 9). As shown in FIG. 5), the elastic support member 360 provided on the bottom frame 26BT of the board housing case 26 is interposed between the board chassis 220 and the bracket 224 on the bottom surface side of the printed board 210 of the main electrical board unit 24a. By contact, an electrical ground connection (ground connection as the mechanical contact means 27) is established between the main electrical board unit 24a and the board housing case 26.

  In any case, regarding the ground connection between the substrate ground of the main electrical board unit 24a and the frame ground of the frame body 26a via the elastic support member 360 constituting the mechanical contact means 27, the elastic support member 360 is connected to the bottom frame 26BT. Is provided in contact with the substrate chassis 220, the contact position is the position where the elastic support member 360 is disposed on the bottom frame 26 BT and is constant. The ground connection system between the substrate ground of the printed circuit board 210 and the frame ground of the frame main body 26a in the assembled state is stable and stable.

  When the front panel 230b is screwed to the frame body 26a after the main electrical board unit 24a has been accommodated and the positional relationship between the two is fixed, as shown in FIGS. 11 and 13 (see also FIG. 9), The board chassis 320 of the additional electrical board unit 24b comes into contact with the board chassis 220 of the main board substrate unit 24a via the protrusion contact portion 326 provided on the board chassis 320, so that the main board unit 24a and the additional board are added. An electrical ground connection (ground connection as the mechanical contact means 28) is established with the unit 24b.

  The board chassis 320 provided with the protrusion contact portion 326 is connected to the board ground of the printed circuit board 310, and the board chassis 220 that is in contact with the protrusion contact section 326 is connected to the board ground of the printed circuit board 210. As a result, the substrate grounds of the main electrical board unit 24a and the additional electrical board unit 24b are connected.

  In addition, when viewed from the side of the additional electrical board unit 24b, the board chassis 220 that is in contact with the protrusion contact portion 326 is screwed together with the front panel 230b, and after assembly, the front panel 230b is screwed with the frame body 26a. Since the frame main body 26a is contacted (connected) via the elastic connection member 232 and the protrusion contact portion 236, the board ground of the additional electrical board unit 24b is connected to the frame ground via the board chassis 220 of the main electrical board unit 24a. It will also do.

  When viewed from the main electrical board unit 24a side, the board chassis 220 of the main electrical board unit 24a is first added via the board chassis 320 of the additional electrical board unit 24b (of course via the protrusion contact portion 326). Since it is connected to the substrate ground of the unit 24b and further to the frame ground (bottom frame 26BT) via the bottom chassis 354 on the back surface (bottom frame 26BT side), the substrate ground of the main electrical board unit 24a is connected to the substrate chassis. It is also connected to the frame ground via 320 and the bottom chassis 354.

  Since the substrate chassis 320 is provided with the protrusion contact portion 326 and the substrate chassis 320 and the substrate chassis 220 are brought into contact with each other, the contact position is the arrangement position of the protrusion contact portion 326 on the substrate chassis 320 and is constant. The ground connection system of the board ground between the boards in the assembled state is stable and stable.

  Second mechanical contact means for connecting the substrate grounds of the printed circuit boards by providing the substrate chassis 320 and the substrate chassis 220 in contact with each other without providing the protrusion contact portion 326 on the substrate chassis 320. It is also possible to construct However, in this case, the contact position is in accordance with the unevenness of each surface and is not constant, and the electromagnetic noise prevention performance with respect to connecting each substrate ground of the printed circuit board 210 and the printed circuit board 310 is This is inferior to the case where the protrusion contact portion 326 is used.

  In the present embodiment, the substrate chassis 320 is provided with the protrusion contact portion 326 so that the substrate chassis 320 and the substrate chassis 220 are brought into contact with each other. However, via the protrusion contact portion 326 that is an example of the mechanical contact means 28. The substrate chassis 220 and the substrate chassis 320 may be in contact with each other, and any one or both of the substrate chassis 220 and the substrate chassis 320 (that is, at least one) may be provided with a protrusion contact portion 326. is there.

  That is, in the embodiment in which only the main electrical board unit 24a is accommodated in the board housing case 26, the frame ground of the frame body 26a and the board ground of the printed board 210 are connected via the elastic support member 360 and the board chassis 220. To do.

  On the other hand, in the form in which a plurality of electrical board units 24 (in the previous example, the main electrical board unit 24a and the additional electrical board unit 24b) are housed in the board housing case 26, the additional electrical board unit 24b, which is an additional board assembly. Is fixed to the frame body 26a in advance, and a bracket 224 as a relay member having conductivity is added to the board chassis 220 for the grounding system of the elastic support member 360, and the elastic support member 360, the bracket 224, and the board are added. The frame ground of the frame body 26 a and the board ground of the printed circuit board 210 are connected via the chassis 220.

  In addition, the additional electrical board unit 24b is provided with a board chassis 320 having a protrusion contact portion 326, and the electrical board units 24a and 24b are fixed to the frame main body 26a so that the positional relationship between them is fixed. When the protrusion contact portion 326 is in contact with the board chassis 220, an electrical ground connection (ground connection as the mechanical contact means 28) is established between the main electrical board unit 24a and the additional electrical board unit 24b. .

  In the present embodiment, the bracket 224 is additionally attached to the board chassis 220 for the grounding system using the elastic support member 360 only when a plurality of electrical board units 24 are accommodated. Even when only the main electrical board unit 24a is accommodated, the bracket 224 may be used. Of course, the bottom chassis 354 is used instead of the attaching / detaching guide 350. In this case, regardless of whether or not the additional electrical board unit 24b is mounted, the structure of the main electrical board unit 24a and the ground connection system of the board ground and the frame ground can be made completely the same.

  In this embodiment, the elastic support member 360 is provided on the bottom frame 26BT side when connecting to the frame ground via the elastic support member 360. However, this is not essential, and the attachment / detachment guide 350 is provided on the substrate. You may attach to the chassis 220 side or the bracket 224 side. However, if the elastic support member 360 is attached to the board chassis 220 or the bracket 224 side, the elastic support member 360 functions as a support member when the main electrical board unit 24a is removed and placed on a work table or the like. This embodiment is preferable because it causes a disadvantage of reducing the performance.

  Further, as shown in FIGS. 10B, 11B, 12B, and 13B, after the main electrical board unit 24a is housed in the board housing case 26, the board The contact surface 26CS provided on the opening side of the top frame 26TP of the storage housing 26 comes into contact with the elastic connecting member 232 attached to the upper end side 230TP of the front panel 230 so as to slightly press (compress). Thereby, with respect to the opening of the substrate storage housing 26, an electrical ground connection (ground connection as the mechanical contact means 29) for taking a mechanical shield of the substrate storage housing 26 and a frame ground is provided as an electrical board. It is taken in common regardless of the number of units 24 accommodated.

  Since the elastic connecting material 232 is provided on the upper end side 230TPT of the front panel 230 and the front panel 230 and the top frame 26TP are brought into contact with each other, the contact position is almost the entire area where the elastic connecting material 232 of the upper end side 230TP is provided. It becomes constant. The ground connection system of the frame ground between the front panel 230 and the top frame 26TP in the assembled state is stable and stable.

  It is also conceivable that the upper end side 230TP of the front panel 230 and the top frame 26TP are in contact with each other (or sides) without providing the elastic connecting material 232 on the upper end side 230TP of the front panel 230. However, in this case, the contact position does not become constant because it corresponds to the unevenness of each surface, and the electromagnetic noise prevention performance with respect to connecting each frame ground of the front panel 230 and the top frame 26TP is This is inferior to the case where the elastic connecting material 232 is used.

  Further, as shown in FIGS. 10B, 11B, 12B, and 13B, the protrusion contact portion 236 provided on the lower end side 230BT of the front panel 230 and the substrate housing case. When the bottom frame 26BT of the body 26 contacts in the vicinity of the reinforcing frame 26FB, an electrical ground connection (mechanism) for mechanically shielding the substrate housing case 26 with respect to the opening of the substrate housing case 26 is provided. The ground connection as the mechanical contact means 29) is made in common regardless of the number of electrical board units 24 accommodated.

  Since the protrusion contact portion 236 is provided on the lower end side 230BT of the front panel 230 and the front panel 230 and the bottom frame 26BT are brought into contact with each other, the contact position thereof is the arrangement position of the protrusion contact portion 236 on the lower end side 230BT of the front panel 230. Becomes constant. The ground connection system of the frame ground between the front panel 230 and the bottom frame 26BT in the assembled state is stable and stable.

  It is also conceivable that the front panel 230 and the bottom frame 26BT are in contact with each other without providing the protrusion contact portion 236 on the front panel 230. However, in this case, the contact position becomes in accordance with the unevenness of each surface and is not constant, and the electromagnetic noise prevention performance with respect to connecting each frame ground of the front panel 230 and the bottom frame 26BT is This is inferior to the case where the protrusion contact portion 236 is used.

  In the present embodiment, the elastic connection member 232 is provided on the upper end side 230TP of the front panel 230, and the protrusion contact portion 236 is provided on the lower end side 230BT, so that the frame ground is provided between the frame body 26a and the top frame 26TP. Although they are connected to each other, the present invention is not limited to this.

  For example, an elastic connection member 232 may be provided on the lower end side 230BT instead of the protrusion contact portion 236. Further, a protrusion contact portion 236 may be provided on the upper end side 230TP in place of the elastic connecting material 232. Further, the elastic connecting member 232 may be provided on the top frame 26TP side instead of being provided on the front panel 230 side. Further, the protrusion contact portion 236 may be provided on the bottom frame 26BT side instead of being provided on the front panel 230 side.

  As described above, in the electrical board accommodation form of the present embodiment, a plurality of electrical board units 24 can be housed in the common board housing case 26, and not only a single board but also a plurality of (for example, function additions or function expansions). However, the connection between the board ground and the frame ground or the frame ground in the assembled state is uniform and mechanically connected to the same system so that there is no variation and the connection is stable. The noise level and the trend are made the same with respect to the noise.

  Regarding the connection between the shielding of the substrate housing 26 and the frame ground, in the case of this embodiment, the connection by screwing to the frame body 26a through the screw opening of the front panel 230, and the elastic connection member 232 of the front panel 230. And the connection by contact with the contact surface 26CS of the top frame 26TP, and the connection by contact between the protrusion contact portion 236 provided on the lower end side 230BT of the front panel 230 and the bottom frame 26BT of the frame body 26a. The grounding shape and the grounding system are maintained regardless of the number of electrical board units 24 (that is, printed circuit board assemblies) accommodated.

<Mounting the board housing and electrical board unit to the main body>
FIG. 14 and FIG. 15 are perspective views showing an example of how the board housing case 26 that houses the electrical board unit 24 is mounted on the apparatus main body 1a and how the electrical board unit 24 is housed in the board housing case 26. It is.

  In mounting the electric board unit 24 and the board housing case 26 on the apparatus main body, the board board housing 26 is removed from the apparatus main body 1a, and the electric board unit 24 is inserted into the board housing case 26 from the housing opening. The frame main body 26a is covered with a top frame 26TP having a cooling fan 26FAN or the like attached thereto, and the substrate housing case 26 on which the electrical board unit 24 is mounted is attached to the apparatus main body. That is, the board storage housing 26 is attached to the apparatus main body after the electrical equipment board unit 24 is first stored in the board storage housing 26 and the top frame 26TP is put on. The housing opening in this case is not limited to the housing opening on the front panel 230 side, but includes the housing opening of the portion from which the top frame 26TP is removed.

  Alternatively, first, the substrate housing case 26 is completed by covering the frame body 26a with the top frame 26TP to which the cooling fan 26FAN or the like is attached, and the substrate housing case 26 is attached to the apparatus body 1a, which is mounted on the apparatus body 1a in advance. It is also possible to adopt a second mode in which the electrical board unit 24 is attached to the board housing casing 26 from the housing opening. The case opening in this case is the case opening on the front panel 230 side. 14 and 15 show the second mode.

  In order to accommodate the plurality of electrical board units 24a and 24b in the board housing case 26, in this embodiment, the main electrical board unit 24a is handled as an electrical board assembly on the side where the main electrical board unit 24a is attached and detached, and the additional electrical board unit 24b is pre- It will be handled as an electrical board assembly on the side to be fixed.

  For example, a top frame 26TP with a cooling fan 26FAN or the like attached to the frame body 26a is covered to complete the substrate housing case 26, and the substrate housing case 26 is attached to the apparatus body 1a as shown in FIG. In the figure, the additional electrical board unit 24b includes the bottom chassis 354, and the bottom chassis 354 is not included in the bottom frame 26BT.

  Then, as shown in FIG. 15, first, the additional electrical board unit 24 b is mounted on the board housing case 26 from the case opening. At this time, the main electrical board unit 24a uses the bracket 224 attached to the board chassis 220 as a support member, and puts it on an appropriate mounting table (for example, a floor or a work table) outside the apparatus main body 1a.

  When the additional electrical board unit 24b is attached as an optional board assembly to the image output terminal 1 to which the main electrical board unit 24a is attached, the main electrical board unit 24a is detached from the board housing case 26 (separation). The bracket 224 attached to the board chassis 220 is used as a support member and placed on a suitable mounting table (for example, a floor or a work table) outside the apparatus main body 1a.

  When the mounting of the additional electrical board unit 24b to the board storage case 26 is completed, the attachment / detachment guide 356 of the bottom chassis 354 is used as the side side attachment / detachment guide to the board storage case 26 from the opening of the case. The substrate unit 24a is mounted.

1 is a diagram illustrating an overall outline of an image output terminal having a function of an image forming apparatus which is an embodiment of an electronic apparatus according to the present invention. It is the perspective view which showed the outline | summary of the arrangement | positioning relationship at the time of accommodating only a main electrical equipment board | substrate unit in a board | substrate storage housing | casing. It is the perspective view which showed the outline | summary of the arrangement | positioning relationship at the time of accommodating a main electrical equipment board unit and an additional electrical equipment board unit in a board | substrate storage housing | casing. It is a figure which shows the outline | summary of the backplane board | substrate which performs the connection between board | substrates. It is the front view which showed the aspect at the time of accommodating each electrical circuit board unit in a board | substrate storage housing | casing. It is the figure which showed the back part of the board | substrate storage housing | casing at the time of accommodating only the main electrical equipment board | substrate unit in a board | substrate storage housing | casing. FIG. 5 is a view showing a back surface portion of a board housing case when a main electric board unit and an additional electric board unit are housed in a board housing case. It is a figure which shows one structural example of the elastic connection material provided in the upper end side of a front panel. It is sectional drawing seen from the front side which shows the mode at the time of accommodating only the main electrical equipment board | substrate unit in a board | substrate storage housing | casing. It is sectional drawing seen from the front side which shows the mode at the time of accommodating a main electrical equipment board unit and an additional electrical equipment board unit in a board | substrate storage housing | casing. It is sectional drawing of the right side surface which showed the aspect at the time of accommodating only the main electrical equipment board | substrate unit in a board | substrate storage housing | casing. It is sectional drawing of the right side surface which showed the aspect at the time of accommodating a main electrical equipment board unit and an additional electrical equipment board unit in a board | substrate storage housing | casing. It is sectional drawing of the left side surface which showed the aspect at the time of accommodating only the main electrical equipment board | substrate unit in a board | substrate storage housing | casing. It is sectional drawing of the left side which paid its attention to the bracket part which showed the mode at the time of accommodating the main electrical equipment board unit and an additional electrical equipment board unit in a board | substrate storage housing | casing. It is the perspective view (the 1) which showed the example of the mounting aspect to the apparatus main body of the board | substrate storage housing | casing which accommodates an electrical equipment substrate unit, and the accommodation aspect of the electrical equipment board unit to a board | substrate storage housing. It is the perspective view (the 2) which showed the example of the mounting aspect to the apparatus main body of the board | substrate storage housing which accommodates an electrical equipment substrate unit, and the accommodation aspect of the electrical equipment board unit to a board | substrate storage housing.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Image output terminal, 1a ... Apparatus main body, 10 ... Image reading part, 12 ... Document feeder, 15 ... User interface part, 20 ... Controller part, 24 ... Electrical board unit, 24a ... Main electrical board unit, 24b, 24c ... Additional electrical board unit, 26 ... board housing, 26a ... frame body, 26BK ... back frame, 26BT ... bottom frame, 26FAN ... cooling fan, 26FB ... reinforcing frame, 26TP ... top frame, 26CS ... contact surface, 27-29 ... Mechanical contact means 30 ... Image output unit 32 ... Image forming unit 34 ... Double-sided copying unit 80 ... Paper feeding unit 90 ... Connection cable 210 ... Printed circuit board 212 ... Power supply connector 213 ... Connector for signal connection, 214 ... external IF connector, 220 ... board chassis, 222 ... L-shaped 223 ... Detachable tip guide, 224 ... Bracket, 226 ... Detachable tip guide, 228 ... Detach prevention guide, 230 ... Front panel, 232 ... Elastic connecting material, 236 ... Projection contact part, 310 ... Printed circuit board, 312 ... Connector for both power supply and signal connection (connector for power supply), 313 ... Connector for signal connection, 314 ... External IF connector, 320 ... Board chassis, 326 ... Projection contact portion, 350 ... Detachment guide 354 ... Bottom chassis (board chassis), 356 ... Detachable guide, 358 ... Projection contact portion, 360 ... Elastic support member, 390 ... Backplane board (relay board), 392 ... Connector for power supply, 393 ... Signal connection Connector, 394... Connector for both power supply and signal connection, 396... Output control connector Kuta

Claims (1)

The device body;
Comprises an opening for accommodating the substrate assembly, mounted on the apparatus main body so as to frame ground is taken, and the substrate storage case detachably two substrates assembly,
Two board assemblies each having an electronic component mounted on a printed circuit board housed in the board housing case,
The board ground of the printed circuit board is electrically connected to the frame ground of the board housing case via a first mechanical contact means,
A conductive board chassis electrically connected to a board ground of the printed circuit board is provided in each of the board assemblies, and a conductive protruding contact having at least one board chassis of the board assemblies adjacent to each other. Are provided, and the board chassis of the adjacent board assemblies are electrically connected via the protruding contact parts ,
In the first mechanical contact means, a contact portion having conductivity and elasticity is provided between the substrate chassis and a mounting surface of the substrate storage housing, and the contact portion having elasticity corresponds to the substrate chassis. Composed of contact,
Of the two substrate assemblies, the substrate assembly that is disposed away from the mounting surface of the substrate storage casing is the substrate storage casing when the substrate assembly is stored in the substrate storage casing. An electronic apparatus configured to be pushed toward the mounting surface by contacting a contact surface provided on the opening side of the electronic device.

Images