JP2007095967A - Shield box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shield box capable of efficient heat-dissipation and shielding of electric wave noise and heat generated by control substrates of various equipment and additional function equipment or the like, without enlarging the shield box itself or dividing it into a plurality of parts, and also, without deteriorating cooling efficiency. <P>SOLUTION: The shield box is composed of a nearly rectangular first box 221 which covers a first circuit block storing electronic components such as a connector for an additional memory and a CPU being a generation source of the electric wave noise and heat, and a second box 222 for covering a second circuit block allowing the additional function equipment or a substrate to be inserted into it or removed from it. The shield box for executing the electric shielding and heat-dissipation is composed by closing an opening in the first circuit block with a lid 25 after forming at least the opening 236 for inserting/removing the additional memory or the like, a cooling air vent hole 243, a partition wall 240 for separating the first box 221 from the second box 222, and a side wall surrounding the periphery with one steel plate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shield box that performs electrical shielding and heat dissipation of a control board or the like in various devices.

  For example, image forming apparatuses such as copiers, printers, facsimiles, and multifunction machines using electrophotographic methods, and other various devices are desired to be downsized and reduced in price due to the demand for personalization. Has been accelerated year by year because of the need to print color photographs and color information.

  In order to realize this high speed, it is necessary to use a CPU, a memory, a clock generator, and the like that have a high processing speed, and in the image forming apparatus, it is necessary to rotate the photosensitive drum and the developing device at a high speed. Peripheral parts such as the CPU and memory generate a large amount of noise and heat, and the amount of heat generated naturally increases by rotating the motor and gears at high speed. Therefore, it is necessary to shield (shield) heat and radio wave noise generated from a plurality of components, and it is also necessary to efficiently dissipate and cool using a powerful fan or a heat radiating plate.

  In addition, if the number of control circuit parts such as connectors increases due to the addition of memory, the control board itself becomes larger. However, in order to make the image forming apparatus and other various devices compact, the installation location of the motor and gear is not sufficient. Therefore, if the control board is square or rectangular, it is difficult to install the control board. Conversely, there is a problem that the image forming apparatus and other various apparatuses must be made large.

  In order to avoid this, if the board is divided and provided, it is necessary to provide the shield box separately. Also, if the parts that generate heat are dispersed, it is necessary to take measures to dissipate heat or to supply cooling air at each heat generating part. As a result, the heat dissipation efficiency deteriorates and the cost increases.

  In particular, in an image forming apparatus and other various devices, a connector of a predetermined standard and a space of a predetermined size are prepared so that an additional function device that can be attached after shipment of the main body and its control board can be loaded. However, these additional functional devices may include heat-generating components in some cases, and the thickness is thicker than that of the substrate. At the same time, measures against heat, shielding of radio noise, etc. are required.

  In order to deal with these problems, for example, in Patent Document 1, in order to effectively use a narrow space in the image forming apparatus, a substrate on which a tall electronic component is mounted upward and a electronic component on which a short height is mounted downward. There is disclosed an image forming apparatus in which two separate substrates are arranged in different steps, and the conveying means of the image forming apparatus is arranged in a space generated by a difference in height of electronic components mounted on both substrates.

  Further, in Patent Document 2, a plurality of substrates are arranged vertically in parallel by covering the periphery of the substrate with a shield plate and arranging shield plates having air communication holes at the top and bottom, and noise entering from the lower opening is detected. A substrate shielding apparatus provided with a duct for attenuating is disclosed.

  Furthermore, in Patent Document 3, each of the sub-shield walls that divide the space between one sheet metal from the peripheral side wall, the center shield wall, and the side wall parallel to the center shield wall into at least two or more is formed. A frame-shaped shield case for magnetic shielding is shown.

  And in patent document 4, in the shield case comprised from the shield frame surrounding the circumference | surroundings of a board | substrate, and the shield cover fitted from the top, a flange part is formed in a part of shield frame, and the hole is formed in the flange part A shield case that fits the shield frame and the shield cover so that the edge of the shield cover is fitted into the hole and a hole is also provided on the shield cover side so that the tip of the tongue-shaped flange portion enters. It is shown.

JP 2004-102165 A Japanese Patent No. 3322748 JP-A-64-44096 JP 2003-133777 A

  However, in the configurations shown in Patent Document 1 and Patent Document 2, two or more boards are used, and in Patent Document 1, the parts are arranged in a vertical step so that the component surfaces face each other. In Patent Document 1, the space for arranging other members is secured by arranging the substrate in two stages, but the space to be shielded becomes larger. In Patent Document 2, the noise is further attenuated. A duct is provided and a large shield member or a member such as a duct is required.

  Further, the shield case shown in Patent Document 3 is shown to efficiently form a shield case with a single sheet metal, but the shield case and the substrate are formed in a rectangular shape, and the motor or gear is formed. When the installation position of the control board is limited due to the installation of the image forming apparatus, the image forming apparatus and other various devices themselves are increased in size.

  Furthermore, the shield case shown in Patent Document 4 is simply a structure for reducing the thickness of the shield case, and no consideration is given to the case of mounting the additional function device that can be attached after the main body is shipped.

  Therefore, in view of the problems of the prior art, the present invention increases the size of the shield box itself to reduce the heat and radio noise generated from a plurality of components, such as control boards of various devices and additional function devices that can be attached after the main body is shipped, and its boards. To provide a shield box that can be efficiently formed without being shielded efficiently without being divided into multiple parts, and without degrading cooling efficiency or increasing the size of various devices themselves. Is an issue.

In order to solve the above problems, the shield box in the present invention is:
A shield box comprising a first box covering a first circuit block on a control board and a second box covering a second circuit block arranged adjacent to the first circuit block;
In the first and second boxes, a partition wall that partitions the first circuit block and the second circuit block and a side wall that surrounds the partition wall are formed of a single sheet metal, and an additional function device or an additional function is provided on the partition wall. An inwardly protruding guide portion for sandwiching and guiding the substrate is formed.

  Thus, the shield box itself can be constructed robustly by configuring the side wall surrounding the periphery of the shield box and the partition wall separating the first circuit block and the second circuit block from a single sheet metal. Even when the amount of heat generated by the blocks is different, it is possible to efficiently cool the blocks individually due to the presence of the partition walls. Furthermore, since the guide part for holding and guiding the additional function device or the additional function substrate is formed on the partition wall, it is not necessary to provide a separate guide, so that the number of parts and the number of assembly steps can be reduced, thereby reducing the cost. .

  The shield box has a ventilation hole for cooling circuit components mounted on the control board, an opening for inserting / removing circuit parts including an additional memory into / from the control board, and the opening can be sealed and opened / closed. By providing such a lid wall, it is possible to easily add or replace circuit components including the additional memory.

  Further, the shield box is attached to the fuser attachment surface of the image forming apparatus and introduces wind from a fan attached to the fuser attachment surface, and is positioned on the opposite side of the shield attachment surface in the shield box. Then, the heat generation from the control board accommodated in the shield box can be efficiently discharged to the outside by being arranged to be discharged to the outside from the outer cover having the slit.

  The first circuit block accommodates a control circuit including a heat generating component, and the slit provided in the outer cover is provided corresponding to the first circuit block, thereby including a control circuit including the heat generating component. The heat generated from can be efficiently exhausted.

  The second circuit block is provided so as to accommodate an additional function device or an additional function board that can be inserted and removed, so that an additional function can be easily added even after shipment. .

  According to the present invention, the shield box itself can be made strong by configuring the side wall surrounding the periphery of the shield box and the partition wall that partitions the first circuit block and the second circuit block with a single sheet metal, Even when the amount of heat generated by each circuit block is different, it is possible to efficiently cool the circuit blocks individually. Furthermore, since the guide part for holding and guiding the additional function device or the additional function substrate is formed on the partition wall, it is possible to reduce the number of parts and the number of assembling steps that do not require a separate guide, thereby reducing the cost.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  1A and 1B show an example of a shield box 22 according to the present invention. FIG. 1A is a perspective view as viewed from the front side (the side covering the control board 20), FIG. FIG. 3 is a development view when the shield box 22 is manufactured from one sheet metal, and FIG. 4 is a view of a lid (lid wall) 25 that closes the opening 226 in the shield box 22. 1 is a perspective view as seen from the front side (A) and the back side (B) as in FIG. 1, and FIG. 5 is a perspective view of the lid 25 closing the opening 226 in the shield box 22 as seen from the front side (A) and the back side (B). 6 is a perspective view showing a connection portion of the shield box 22 that covers the first circuit block and the second circuit block of the control board 20, and FIG. 7 shows the first circuit block. FIG. 8 is a perspective view of a relay board that mounts a control circuit that could not be mounted and connects the first circuit block and a control target. FIG. 8 is a view of the state where the relay board shown in FIG. FIG. 9 is a perspective view showing a state in which the shield box 22 according to the present invention is mounted on an exterior peripheral device of an image forming apparatus as an example in various devices, with the lid 25 removed, and FIG. 10 in the present invention. FIG. 11 is a cross-sectional view showing a structure in which the shield box 22 and the control board 20 are attached to the image forming apparatus main body side frame as an example in various devices. FIG. 11 is a diagram in the vicinity of incorporating a gear for driving the image forming device as an example in various devices. The perspective view of the state in which the control board 20 and the shield box 22 of the present invention are incorporated as seen from the back side of the control board 20 12 is a perspective view showing a state in which a reduction gear for driving an image forming apparatus as an example in various devices is incorporated, and a shield box 22 of the present invention is attached, and FIG. 13 is a diagram of an image forming apparatus as an example in various devices. FIG. 14 is a perspective view showing a state in which the outer cover is removed and the shield box 22 of the present invention is incorporated in the main body frame, and FIG. 14 is an illustration of an image forming apparatus as an example in various devices, and the shield box of the present invention is incorporated. It is the perspective view seen from the left side. In the following description, the case where the present invention is applied to the image forming apparatus 10 will be described as an example, but it is obvious that the present invention can be applied not only to the image forming apparatus but also to various similar devices.

  FIG. 14 is an external perspective view in which the internal mechanism of the image forming apparatus 10 taken as an example of various devices is omitted. The image forming apparatus 10 includes a paper discharge unit 13 that discharges a recording medium on which a toner image is fixed on the front side on the left side in FIG. Further, the side cover 11 on the front side in the figure (right side when viewed from the front side of the image forming apparatus 10) is provided with an air intake 112 by an air vent slit 111 and a fan (not shown). A control board for controlling the image forming apparatus 10 and a shield box for shielding and radiating radio noise generated from the control board are provided in the main body frame inside the side cover 11. In the following description, a case where the shield box is provided on the front side of the image forming apparatus 10 will be described as an example, but it is obvious that the shield box may be provided on the back side of the figure.

  An image forming apparatus 10 as an example of various devices in which the shield box 22 according to the present invention shown in FIG. 14 is incorporated is a photosensitive member (not shown) for forming a latent image around the photosensitive member. A charging device, an exposure device, a developing device that develops the formed latent image into a toner image, a transfer unit that transfers the toner image to a recording medium, a cleaning device that cleans the toner remaining on the photoconductor after the transfer, and the like Furthermore, after the recording medium is transported to the transfer position of the photosensitive member and the toner image is transferred, the transporting means for transporting the toner image to the fixing medium by transporting it to the fixing device and further transporting it to the discharge position is provided. In order to drive them, a motor and a fan are provided to discharge heat generated inside the image forming apparatus main body.

  FIG. 13 is a perspective view showing the assembled state of the shield box 22 with the side cover 11 in FIG. 14 removed. The shield box 22 is provided with a lid (lid wall) 25 that partially covers the opening, and is incorporated into the main body frame 12 of the main body frame 12 on the front right side of the figure in the image forming apparatus 10. In addition, a control board of the image forming apparatus 10 is disposed inside thereof. In addition, a direct drive motor 15 that drives a photoreceptor, a developing device, a fixing device, and the like (not shown) in the image forming apparatus 10 is provided in the main body frame 12, and the wind of the fan 14 that sends cooling air into the image forming apparatus 10. Located in the middle of the road, it is efficiently cooled. In addition, a control circuit or the like that could not be mounted on the control board is mounted, and the relay board 30 on which the heat generating components are mounted by connecting the control board and the control target in the image forming apparatus 10 is also arranged in this air path. In addition, a motor 16 that drives a conveyance device such as a recording medium by a gear is incorporated in the main body frame 12.

  The shield box 22 is positioned so that the slit 111 in the side cover 11 is on the side opposite to the attachment surface to the main body frame 12. Therefore, a part of the cooling air that enters through the ventilation holes on the fan 14 side in the shield box 22 passes through the ventilation holes on the side cover 11 side and the slits 111 as heat from the components mounted on the control board arranged inside the shielding box 22. Heat is exhausted by being discharged to the outside.

  The shield box 22 includes a first box 221 that covers the first circuit block on the substrate to be accommodated, and a second box 222 that covers the second circuit block, and is surrounded by a side wall. And a partition wall for partitioning the first circuit block and the second circuit block. The first box 221 is formed in a vertically long, substantially rectangular parallelepiped shape, and is covered with a lid (lid wall) 25 that can be opened and closed by opening the side cover 11 side. The second box 222 is formed in a horizontally long, substantially rectangular parallelepiped shape, is connected to the first box 221 via a partition wall (not shown), and has a front ceiling wall 234 on the side cover 11 side. Therefore, the first box 221 in the shield box 22 is provided with an opening that can be opened and closed by the lid 25, so that when the side cover 11 is removed and the lid 25 is opened, the components on the board covered by the shield box 22 are opened. Can be added or replaced. In addition, since the partition wall separates the first box 221 and the second box 222 so that the internal components can be cooled independently, the first box 221 and the second box 222 are functionally respectively. Different parts can be accommodated and different cooling effects can be obtained.

  FIG. 2 is a perspective view of an example of the control board 20 on which a control circuit for controlling the image forming apparatus 10 as an example of various devices is mounted. The control board 20 is provided inside the shield box 22 as described above, and controls the entire image forming apparatus on which a plurality of standard electronic components for control are mounted as a substantially rectangular shape vertically long in the figure. The first circuit block 202 or a substantially rectangular shape that is horizontally long in the left-right direction in the figure, and an additional function device can be additionally mounted later so that the right side is substantially aligned with the right side of the first circuit block 202. The connector connecting the second circuit block 203, the first circuit block 202 and the control target of the image forming apparatus 10 is accommodated, and the connector block 201 exposed from the shield box 22 is arranged.

  The first circuit block 202 collects and stores high-frequency processing components and heat generating members that generate particularly large amounts of radio waves and heat, such as a CPU (Central Processing Unit) 212, various memories, and a clock generator 213. In addition to the various electric circuit components represented by the CPU 212, the clock generator 213, etc., the first circuit block 202 includes an EPROM (Erasable and Programmable Read Only) that is inserted into and removed from the control board 20 from the vertical direction. Memory) Connector 214 for additional board, DIMM (Dual Inline Memory Module) connector 215, DDR SDRAM (Double Data Rate Synchronous Dynamic Access Memory) board 16 for additional board control, etc. Connectors that can be inserted and removed from the vertical direction are mounted.

  Further, the second circuit block 203 includes a hard disk (HD) connector 217, a compact flash (registered trademark) (CF) so that it can be additionally inserted into and removed from the control board 20 later after the main body is shipped. And additional function equipment connectors such as a card receiving connector 218 for a card such as a microdrive are mounted correspondingly. The card receiving slot connector 218 in FIG. 2 shows a state in which a memory card such as a CompactFlash (registered trademark) is inserted, but it does not show a normal use state but is added as an option. Note that it shows the state of being done.

  Therefore, by opening the lid 25 of the first box 221 in the shield box 22, the above connectors are arranged in a direction in which these memory boards can be inserted and removed, and a connector of an additional function device provided in the second circuit block 203. The direction in which the additional function device is attached is formed in parallel to the front ceiling wall 234 of the second box 222, so that the first circuit block 202 and the second circuit block 203 are respectively in the first box 221. Then, the circuit components can be inserted / removed or attached without enlarging the second box 222. That is, a component inserted into and extracted from the first circuit block 202 is a relatively short component such as a memory board, and a component attached to the second circuit block 203 is a relatively large component such as a hard disk. Accordingly, when these insertion / extraction or attachment directions are changed, the boxes surrounding each increase as described above, but such a configuration can be avoided by adopting the configuration described above.

  The connector block 201 is also provided with connectors and the like that connect the first circuit block 202 and a control target in the image forming apparatus. The connector block 201 is arranged on one side of the first circuit block 202 so as to protrude in the same direction as the protruding direction of the second circuit block 203. Therefore, the control substrate 20 is formed in a substantially U shape as a whole and has a recess 204 formed therein.

  FIG. 1 is an example of a shield box 22 that covers the control board 20 shown in FIG. FIG. 1A is a perspective view of the shield box 22 as viewed from the front side (the side covering the control board 20), and FIG. 1B is a perspective view of the shield box 22 as viewed from the back side. As described above, the shield box 22 has a substantially rectangular parallelepiped shape and is on the upper side in the figure. The first box 221 is configured such that the lid 25 covering the opening can be freely opened and closed, and the first box 221 has a partition wall 240. And a second box 222 which is connected to the lower side through a substantially rectangular parallelepiped shape.

  The first box 221 covers the first circuit block 202 on the control board 20, and the second box 222 covers the second circuit block 203. As described above, when the shield box 22 is attached to the image forming apparatus 10, the cooling air from the fan 14 enters the first box 221 through the ventilation holes 243 formed in the side wall 223. Further, on the side wall 224 facing the side wall 223, as shown in FIG. 1B, various connector openings 237 for exposing connectors such as USB, LAN, and parallel interface are arranged in the vertical direction in the figure. An opening 236 for inserting / removing an additional function device or a board is provided on the second box 222 side. The side wall 224 is exposed outside the apparatus main body when the shield box 22 is attached to the image forming apparatus 10 (see FIG. 13).

  FIG. 3 is a development view of the shield box 22. The shield box 22 is made of a single sheet metal having a thickness of about 0.5 mm in consideration of ease of processing and assembly, a heat dissipation effect, and the like. Among these, in order to insert and remove the left and right side walls 223 and 224, the upper surface wall 225 on the upper surface side in the drawing, the memory board, and the like on the rectangular first box 221 side corresponding to the first circuit block 202. A substantially rectangular opening 226 and the like are provided.

  Also, on the second box 222 side corresponding to the second circuit block 203, side walls 231 and 232 which are also left and right, a lower wall 233 which is the lower surface side, and a front ceiling wall 234 which is the side cover 11 side are provided. It has been. The right side wall 232 of the second box 222 is connected to the same right side as the right side wall 224 of the first box 221. The heights of the side walls 223, 224, 231, 232, the upper surface wall 225, the lower surface wall 233, the partition wall 240, and the wall 241 are the standard electrical components and memory substrates accommodated in the first circuit block 202 of the control board 20, It is set according to the height of an additional function device or a board accommodated in the second circuit block 203.

  The opening 226 on the first box 221 side inserts and removes various memories and boards from the control board 20 in the direction perpendicular to the control board 20 when the lid 25 is removed. The area is set so that a large exposure space is formed. Further, a partition wall 240 that separates the first box 221 and the second box 222 is raised from the portion that becomes the opening 226 on the second box 222 side. Furthermore, a wall 241 on the first box 221 side, which is a portion extending on the fan 14 side in the second box 222, is formed from the extending portion of the side wall 231.

  Of these, the right side walls 224 and 232 are provided with various connector openings 237 that expose connectors such as USB, LAN, and parallel interface in the vertical direction in the figure, and are used to insert and remove additional function devices and boards. An opening 236 is provided on the second box 222 side. Further, the lower wall 233 and the partition wall 240 are provided with two pairs of guide members 235 for guiding a substrate and a hard disk accommodated in the second box 222 by pressing, and the hard disk and the substrate are interposed between the guide members 235. It can be inserted while holding.

  The side walls 223 and 231, the top wall 225, the bottom wall 233, and the front ceiling wall 234 have ventilation holes 243 for sending the wind sent from the fan 14 into the shield box 22 or from the shield box 22 to the outside. Is provided. The portion of the first box 221 that is provided with a reference numeral 227 around the opening 226 is a frame wall, and the portion of the frame wall 227 that is provided with a belt-like reference numeral 228 provided on the opening 226 side is the portion of the frame wall 227. It is a bent peripheral portion, and the bent peripheral portion 228 is bent toward the control substrate 20 side by about 135 degrees to form an opening peripheral portion 229. That is, the opening edge of the sheet metal is not exposed by the opening rim 229, and the user is prevented from cutting his / her hand when inserting / removing various memory boards into / from the connectors 214, 215 and 216 of the first circuit block 202 from the opening 226. It is possible to cope with PL (product liability).

  The frame wall 227 is provided with a receiving hole 230 formed in a slit shape so that a tongue piece provided on the lid 25 to be described later can be inserted and the lid 25 can be rotated. Furthermore, a slant piece 242 having a predetermined width is provided at the end of the wall 241 so that the cooling air can pass between the first box 221 and the second box 222, and a gap is formed between the wall 241 and the partition wall 240. It is supposed to be.

  The shield box 22 is attached to the main body frame 12 of the image forming apparatus 10 through screws through the screw holes 50 to 58 as shown in FIG. Note that the heights of the side walls 223, 224, 231, 232, the upper surface wall 225, the lower surface wall 233, the partition wall 240, and the wall 241 are set to the standard electric machine accommodated in the first circuit block 202 of the control board 20 as described above. It is set in accordance with the heights of components, memory boards, additional function devices and boards accommodated in the second circuit block 203.

  The details of the left side wall 223 side of the first box 221 and the frame wall 227 side of the intersection portion where the substantially rectangular long side of the second box 222 intersects in a T shape will be described in detail with reference to FIG. In order to make the partition wall 240 and the left side wall 223 easier to bend, a notch 402 is made. However, if it is left as it is, it becomes very narrow and becomes the narrowest part and weakens. It is reinforced.

  4 is a perspective view (A) of the shield box 22 seen from the front side and a perspective view (B) seen from the back side, similar to FIG. 1, except for the lid (lid) 25 that closes the opening 226 in the shield box 22. FIG. . In the shield box 22, first, a notch as shown in the development view of FIG. 3 is made in one sheet metal, and the guide member 235 is formed by bending or pressing at a predetermined portion. Thereafter, the bent peripheral edge 228 provided on the frame wall 227 around the opening 226 is bent 135 degrees or more to the control substrate 20 side to form the peripheral edge 229 of the opening 226. And each side wall 223,224,231,232, the upper surface wall 225, the lower surface wall 233, the partition wall 240, and the wall 241 are each bent so that it may become the control board 20 side, and also the piece provided with screw holes 50-58 is a control board. It can be easily formed by bending it in a direction parallel to 20.

  Therefore, the processing and assembly of the shield box 22 are very easy and can be provided with high strength, and the first circuit block 202 on the control board 20 can be formed by using a single sheet metal. The heat from the heat source such as the CPU 212 is also transferred from the first box 221 to the second box 222 of the shield box 22 and becomes a large heat radiating plate as a whole. Become. Furthermore, the wall 241 is provided on the extension of the left side wall 231 formed by bending the short side of the front top wall 234 as described with reference to FIG. The direction is shifted by 90 degrees with respect to the bending direction. Therefore, as can be seen from FIG. 4 (B), it cannot be opened any more by hitting the left side wall 223, and it can be reliably held when the additional function device is inserted.

  Further, the slant piece 242 that is the tip of the wall 241 is bent obliquely by a predetermined angle toward the first box 221 so that a gap can be formed between the partition 240 and the second box 221 to the second box 221. An air path to the box 222 can be formed. Moreover, since the 2nd block 222 is formed with the front ceiling wall 234, it can maintain big intensity | strength.

  FIG. 5 is a perspective view (A) of a lid (lid) 25 closing the opening 226 in the shield box 22 as viewed from the front side and a perspective view (B) of the lid as viewed from the back side. The lid 25 is formed in a substantially rectangular shape from one sheet metal like the shield box 22 and has a number 251 near the peripheral edge so as to protrude in a direction opposite to the control board 20 in order to ensure strength. A step having the reference numeral of the upper portion 252 is formed by being pressed at the portion marked with. Further, on the partition 240 side of the upper portion 252, a stepped portion 253 that protrudes in a direction opposite to the control substrate 20 is provided.

  The projecting height of the stepped portion 253 from the control board 20 is such that an additional memory board or the like higher than the height of the shield box 22 can be inserted into the connector 216, and The height is set such that the stepped portion 253 is in contact with the side cover 11 or is located with a slight gap so that the gap with the side cover 11 can be made constant. Therefore, it is possible to mount an additional memory board or the like that is higher than the height of the shield box 22 from the board 20, and when the lid 25 is not normally closed, the side cover 11 is attached to the image forming apparatus 10. When covered, the side cover 11 cannot be positioned at the correct position due to the presence of the stepped portion, and it can be recognized that there is a problem in the mounting state.

  Then, the lid 25 is bent with a predetermined width at the peripheral edge on the left side in FIG. 5A and on the right side in FIG. 5B so as to be on the side wall 223 side in the shield box 22. The portions 254 and 255 are provided, and protrusions 259 are formed at predetermined intervals on the inner side when bent. Further, in the vertical direction in the figure of the lid 25, bent portions 256 and 257 having protrusions 259 formed at predetermined intervals are provided on the outer side when bent. The protrusions 259 provided on the bent portions 254, 255, 256, 257 are such that the protrusions 259 of the bent portions 254, 255 squeeze the side wall 223 of the shield box 22, and the protrusions 259 provided on the bent portions 256, 257 are The peripheral portion 229 formed by the opening bent portion 228 of the opening 226 in the shield box 22 is squeezed to ensure conduction with the shield box 22 and to fit the lid 25 so that it does not easily fall off. Yes.

  Further, a lid rotation receiving hole 230 (see FIG. 4 (FIG. 4 (A))) provided on the frame wall 227 of the shield box 22 is provided on the periphery of the lid 25 on the right side in FIG. 5 (A) and on the left side in FIG. 5 (B). A tongue piece 258 to be inserted into A) is formed. The tongue side 258 is inserted into the lid rotation receiving hole 230 and rotated in a direction to close the opening 226 so that the opening 226 can be closed. At that time, the protrusions 259 provided on the peripheral bent portions 254, 255, 256, and 257 squeeze the side wall 223, and the protrusions 259 of the bent portions 256 and 257 squeeze the bent peripheral portion 228 of the opening 226. And fit. By squeezing the side wall 223 and the peripheral edge portion 229 with the protrusions 259 in this manner, the lid 25 is fitted without being detached from the shield box 22, and conduction with the shield box 22 is also secured to close the opening 226. be able to. Note that the upper portion 252 of the lid 25 is appropriately provided with a ventilation hole 243 for ventilation.

  When the lid 25 is attached to the shield box 22, it has recently been considered that the side wall 223 and the peripheral portion 229 are squeezed by the protrusions 259 provided on the peripheral bent portions 254, 255, 256, 257, even for a seal sheet metal. For this reason, chrome cannot be used and an organic film (insulator) is used as a film member, so that the surface is rubbed strongly and the surface is rubbed to obtain a conductive effect between the lid 25 and the shield box 22. Due to the ironing performed when closing the opening 226, a large bending stress is applied to the lid 25 during opening and closing, but the lid 25 is provided with the upper portion 252 formed by the press portion 251 as described above, and thus warped. Or deformed.

  FIG. 6 is a perspective view showing a connection portion of a portion covering the first circuit block 221 and the second circuit block 222 in the shield box 22. As described with reference to FIG. 3, this portion has a frame wall 227 at the intersection where the left side wall 223 side of the first box 221 and the substantially rectangular long side of the second box 222 intersect in a T shape. On the side, a notch 402 is made to make it easier to bend the partition wall 240 and the left side wall 223. However, if this part is left as the width of the frame wall 227, it becomes thinner and weakened by the notch 402. Is formed in a tapered shape so that it can be reinforced.

  FIG. 7 is a perspective view of the relay board 30 that is mounted with a control circuit or the like that could not fit in the first circuit block 202 of the control board 20 and can be connected to a control target in an image forming apparatus as various devices. . By using this relay board 30, various additional functions that could not be mounted on the control board 20 can be added. However, such a relay board 30 usually has a problem in its installation location.

  However, as described with reference to FIG. 2, the control board 20 is adjacent to the short side of the first circuit block 202 having a substantially rectangular shape and the long side of the second circuit block 203 having a substantially rectangular shape. The connector block 201 protrudes in the same direction as the protruding direction of the second circuit block 203 at the end opposite to the side where the second circuit block 203 is adjacent in the first circuit block 202, and is substantially U-shaped as a whole. Or a substantially inverted U-shape. Therefore, a part of a gear or a motor for driving such a relay substrate 30 and a unit including the photosensitive drum can be accommodated in the substantially U-shaped recess 204.

  FIG. 8 is a perspective view of the state in which the relay board 30 as shown in FIG. 7 is installed in the concave portion 204 of the control board 20 formed in the substantially U shape, as seen from the rear, as described above. The control board 20 is provided with a recess 204, and the shield box 22 is also provided with a first box 221 and a second box 222 in a substantially inverted L shape, and the control board 20 has a portion corresponding to the recess 204. Since there is nothing, the relay board 30 can be installed in this way.

  FIG. 9 is a perspective view showing a state in which the shield box 22 is mounted on the exterior peripheral device of the image forming apparatus as various devices with the lid 25 removed. In the example shown in FIG. 9, the motor 17, which is a driving source for driving the photosensitive drum and the developing device in the image forming apparatus 10, the recording medium transport device, and the like together with the relay substrate 30 in the recess 204 in the control substrate 20. And a gear 19 for transmitting the driving force of the motor 17 to each unit described above is disposed. In order to make the image forming apparatus 10 small in this way, the positions of the motor 17 and the gear 19 are arranged. Even in a limited case, by providing the recess 204 in the control substrate 20, the image forming apparatus itself can be accommodated without increasing its size.

  FIG. 11 is a perspective view of the state in which the control board 20 shown in FIG. 9 and the shield box 22 of the present invention are combined as seen from the back side of the control board 20. That is, as described with reference to FIG. 9, the motor serving as a driving source for driving the photosensitive drum, the developing device, the recording medium conveying device, and the like in the image forming apparatus 10 together with the relay substrate 30 in the concave portion 204 in the control substrate 20. 17, and even when a gear 19 or the like for transmitting the driving force of the motor 17 to each unit described above is provided, the recess 204 is provided in the control substrate 20 so that the image forming apparatus itself can be accommodated without increasing its size. It turns out that it is possible to do.

  FIG. 12 is a perspective view showing an example in which a motor 16 for conveying a recording medium in the image forming apparatus is further added. In an image forming apparatus as various devices, even if a single motor cannot drive all of the above units due to high speed, for example, the photosensitive drum is driven by the direct drive motor 15 and decelerated by the reduction gear 18. In addition to driving the developing device, the other motor 16 may be a drive source for transporting the recording medium. However, even when the positions of the motors 15 and 16 and the reduction gear 18 are limited, the control is possible. By providing the recess 204 in the substrate 20, the image forming apparatus itself can be accommodated without increasing the size.

  FIG. 10 is a cross-sectional view taken along line XX in FIG. 9 and shows a structure for attaching the shield box 22 to the main body frame 12. In the figure, 500 is a screw, 20 is a control board, and the shield box 22 is the same as the first box 221 and the first box 221 as shown in FIG. 1 (B), FIG. 3, FIG. 4 (B), and FIG. Screw holes 50, 51, 52, 53, 54, 55, 56, and 57 are provided below the second box 222. For this purpose, this screw hole is used and fixed to the main body frame 12 while being grounded with the screw 500 as shown in FIGS. Of these, the two screws 51 and 52 are fastened together with the control board 20 as shown in FIG.

  In the embodiment of the present invention described above, the ventilation holes 243 are uniformly formed in the shield box 22. However, in consideration of the shielding effect of heat and radio waves and the air path during discharge, A surface wall other than the left side wall 231 and the lid 25 may be selectively formed.

  As described above, according to the present invention, the shield box includes the side wall that surrounds the periphery of the shield box and the partition wall that partitions the first circuit block and the second circuit block. Even if the circuit blocks have different amounts of heat, they can be individually and efficiently cooled by the presence of the partition walls. Furthermore, since the guide part for holding and guiding the additional function device or the additional function substrate is formed on the partition wall, it is not necessary to provide a separate guide, so that the number of parts and the number of assembly steps can be reduced, thereby reducing the cost. .

  According to the present invention, the shield box itself is enlarged or divided into a plurality of heat and radio wave noises generated from a plurality of components such as a control board constituting various devices and an additional function device which can be attached after the main body is shipped and the substrate. The shield box itself can be formed economically without degrading the cooling efficiency and increasing the size of the various devices themselves. It can be applied to provide a suitable shield box.

FIG. 4 is a perspective view (A) viewed from the front side (side covering the control substrate) and a perspective view (B) viewed from the back side of an example of the shield box in the image forming apparatus according to the present invention. It is an example perspective view of a control board which performs electrical shielding and heat dissipation by a shield box according to the present invention. It is an expanded view at the time of manufacturing the shield box which becomes this invention with one sheet metal. FIG. 2 is a perspective view (A) viewed from the front side and a perspective view (B) viewed from the back side, similar to FIG. 1, except for a lid (lid) that closes the opening in the shield box according to the present invention. They are the perspective view (A) which looked at the lid | cover (lid) which closes the opening part in the shield box which becomes this invention from the front side, and the perspective view (B) seen from the back side. It is the perspective view which showed the connection part of the part which covers the 1st circuit block and the 2nd circuit block in the shield box which becomes this invention. It is a perspective view of the relay board which mounts the control circuit etc. which could not be mounted in the 1st circuit block, and connects the 1st circuit block and the controlled object. It is the perspective view which looked at the state which connected the relay board | substrate shown in FIG. 7 to the control board from the back. It is a perspective view which shows the state which mounted the shield box of this invention in the state which removed the lid | cover (lid) to the exterior peripheral apparatus of the image forming apparatus. FIG. 3 is a cross-sectional view showing a structure for attaching the shield box in the present invention to the image forming apparatus main body side frame. FIG. 3 is a perspective view of a state in which a control board and a shield box of the present invention are incorporated in the vicinity of a gear driving the image forming apparatus when viewed from the back side of the control board. FIG. 5 is a perspective view showing a state in which a reduction gear for driving the image forming apparatus is incorporated and a shield box of the present invention is attached. It is the perspective view which showed the state which removed the exterior cover of the image forming apparatus, and incorporated the shield box of this invention in the main body frame. It is the perspective view seen from the side which abbreviate | omitted the internal mechanism in an image forming apparatus, and incorporated the shield box of this invention.

Explanation of symbols

11 Side cover (outer cover)
DESCRIPTION OF SYMBOLS 111 Slit 14 Fan 20 Control board 202 1st circuit block 203 2nd circuit block 22 Shield box 221 1st box 222 2nd box 223 Left side wall 224 Right side wall 225 Top surface wall 226 Opening 227 Frame wall 228 Folding rim 229 Opening edge 230 Lid rotation receiving hole 231 Left side wall 232 Right side wall 234 Front ceiling wall 233 Bottom wall 235 Guide member (guide part)
236 Additional function device insertion / removal opening 237 Various connector openings 240 Bulkhead 241 Bulkhead 242 Slope 243 Ventilation hole 25 Lid (lid wall)
251 Press part 252 Upper part 253 Step part 254, 255, 256, 257 Peripheral bent part 258 Tongue side 259 Projection 30 Relay substrate 401 Tape part 402 Notch 50, 51, 52, 53, 54, 55, 56, 57 58 screw holes

Claims (5)

A shield box comprising a first box covering a first circuit block on a control board and a second box covering a second circuit block arranged adjacent to the first circuit block;
In the first and second boxes, a partition wall that partitions the first circuit block and the second circuit block and a side wall that surrounds the partition wall are formed of a single sheet metal, and an additional function device or an additional function is provided on the partition wall. A shield box characterized in that a guide portion protruding inward to guide the substrate while being sandwiched is formed.   The shield box includes a ventilation hole for cooling circuit components mounted on the control board, an opening for inserting / removing circuit parts including an additional memory into / from the control board, and a lid that seals the opening and can be opened and closed. The shield box according to claim 1, further comprising a wall.   The shield box is attached to the fuselage attachment surface of the image forming apparatus, introduces wind from a fan attached to the fuser attachment surface, and is positioned on the opposite side of the shield attachment surface in the shield box. The shield box according to claim 1, wherein the shield box is disposed so as to be discharged from an outer cover having a slit.   The said 1st circuit block accommodates the control circuit containing a heat-emitting component, The slit provided in the said outer cover is provided corresponding to the said 1st circuit block. Shield box described.   5. The shield box according to claim 1, wherein the second circuit block accommodates an additional function device or an additional function board that can be inserted and removed.

Images