JP2009117493A - Electrical equipment unit and image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure for efficiently cooling the surface of an electrical equipment substrate and the reverse thereof at the same time while reducing the size of an electrical equipment unit. <P>SOLUTION: The electrical equipment unit includes: a shield case 51; the electrical equipment substrate 43 installed in the shield case via an airspace between a bottom plate 54 of the shield case and itself, and mounted with a plurality of electronic components, at least one of electronic components 46 being mounted with a heat sink 45; a fan 48 for air-cooling the electrical equipment substrate; a fan supporting member 49 for supporting a fan obliquely to the flat face of the electrical equipment substrate in such an inclined attitude that at least part of wind hits the heat sink; and a vent hole 47 located at a position between the electronic component mounted with the heat sink and the fan where the wind of the fan in the inclined attitude hits while passing through the electrical equipment substrate in the direction of its thickness. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrical unit including an electrical board and a cooling mechanism, and an image processing apparatus equipped with the electrical unit.

  In recent years, image processing apparatuses such as digital multi-function peripherals have been colorized and speeded up, and the processing speed of electronic devices mounted on an electrical board that controls the apparatus has also been increased. Increasing the processing speed of electrical or electronic devices on a substrate increases power consumption and, as a result, increases the amount of heat generated by the device. Further, while the amount of heat generation is increasing, the heat generation density is increasing due to the reduction of the cooling space due to the downsizing of the apparatus. Furthermore, the number of cooling fans is decreasing to reduce the cost of the main body. Under such circumstances, HDDs and the like that are vulnerable to heat are mounted in the apparatus, and problems such as a decrease in life due to heat are increasing. For these reasons, there is a need for a cooling structure that can efficiently cool an electrical board at a low cost.

JP 2007-59731 A JP-A-2005-40325.

  Patent Document 1 discloses a configuration in which cooling air is guided in a direction perpendicular to the axial flow direction of the fan with a bent heat sink by using a bent heat sink, and a fan axial flow. An embodiment is described in which a substrate is disposed at the center and the upper and lower sides of the substrate are cooled at the same time. Patent Document 2 describes a cooling structure inside a rice cooker in which a fan 30 is disposed in an inclined manner inside the rice cooker to cool a heat sink 32 thereabove.

  An axial fan generally has an air volume distribution curve as shown in FIG. 10, and since there is an axis near the axis center, the air volume is small, and the vicinity of the center of one blade is the maximum air volume. It has the characteristic that the air volume decreases as it goes to the periphery. The axial fan has a built-in motor for rotating the fan at the center, and has a plurality of blades. When power is supplied to the fan, the blades are rotated by the motor, and wind can be sent in one direction. The air volume can be changed depending on the number and angle of blades, the number of rotations, and the like. FIG. 10 shows the air volume distribution of a general axial fan. As described above, wind can be sent in one direction by rotating the blades. However, since the motor is located at the center of the axial fan, the air volume near the center is small. It has the feature that the central part of the blade has the maximum air volume.

  In general, in an electrical board, a large electronic component is often mounted on the front surface (component surface side), and a small surface mounted component is often mounted on the back surface (solder surface side). If such an electrical board is to be cooled by the conventional technique, the electrical board is positioned at the center of the fan, and the air volume in the vicinity of the board is reduced. In such a case, when a surface-mounted component that generates heat is mounted, the effect of cooling the electronic component is reduced. In order to solve these problems, for example, as disclosed in Patent Document 1, a fan is provided near the substrate to cool it.

  (A) of FIG. 11 is the figure which looked at the cooling mechanism of the prior art described in patent document 1, for example from the side. As described above, axial fans have a characteristic air volume distribution. If a board and fan are installed as in the conventional technology, only the air at the bottom of the fan may hit the heat sink, Is not fully utilized. In order to make the best use of the airflow of the fan, a heat sink having the same height as the fan is required. FIG. 11B is a side view of the cooling mechanism of the related art.

  FIG. 12 is a side view of a conventional cooling mechanism. In the conventional technology, since the electrical board is placed in the center of the fan, if the electrical board is stored in a limited space, the space on the board surface (component side) is reduced, while the back surface of the board (solder) A useless space is created on the front side. As described above, since a plurality of electronic components are generally mounted on the component surface side and small surface-mounted components are mounted on the solder surface side as described above, a large space is not required on the solder surface side. In the system, a space corresponding to the radius of the fan is inevitably provided. On the other hand, only the space corresponding to the radius of the fan can be obtained on the component surface side, and the space necessary for heat radiation is narrowed, resulting in a decrease in cooling efficiency. In the conventional technology, the airflow of the fan on the board surface (component side) and the board back side (solder side) is almost the same. However, as described above, The cooling efficiency is poor when the front and back surfaces are cooled with the same air volume.

(1) In the conventional fan mounting method as shown in FIG. 11 (a), the device mounted on the substrate because the substrate is located below the fan with respect to the airflow distribution of the axial fan. When cooling the device, the device can be cooled only by the wind flow at the bottom of the fan, and the wind flow in the upper half of the fan is wasted, resulting in poor cooling efficiency. If you try to use the upper half of the fan, you will need a heat sink of the same size as the fan. In addition, since the air volume of the fan is not effectively utilized, the cooling effect is deteriorated, and as a result, the size of the fan is increased and a space in the height direction is required.
(2) In the prior art, as shown in FIG. 11B and FIG. 12, the vicinity of the shaft corresponds to the board part, so the part with a small airflow of the fan is located at the same position as the part of the surface mount component on the board. In these surface mount components, sufficient airflow cannot be obtained, and the cooling effect may be reduced.
(3) Since the fan is mounted perpendicular to the board, a space equivalent to the height of the fan is required.
(4) The bent part for rectifying the air blown from the fan is required on the heat sink, and the shape is restricted.
(5) The size of the heat sink is increased by including a bent portion in the heat sink, leading to an increase in the cost of the heat sink,
(6) Due to the restrictions in (2) above, there are restrictions on the component mounting arrangement.
Such a problem occurs.

  In the cooling structure described in Patent Document 2, the back side of the substrate 20 (the back side of the mounting surface of the heat sink 32) cannot be cooled by the fan 30.

  The first object of the present invention is to efficiently cool the front surface of the electrical board and simultaneously cool the back surface. In addition, it is a second object of the present invention to provide a cooling structure that enables downsizing of an electrical unit having an electrical board.

(1) Shield case (51);
In the shield case, a plurality of electronic components installed with a gap between the shield case and the bottom plate (54) are mounted, and at least one of the electronic components (46) is mounted with a heat sink (45). Electrical board (43);
A fan (48) for air-cooling the electrical board;
A fan support member (49) that supports the fan in an inclined posture so that at least part of the wind hits the heat sink at an angle with respect to the plane of the electrical board; and
The electrical board is located between the electronic component (46) on which the heat sink is mounted and the fan (48), and the fan is in a position where the fan winds due to the inclined attitude of the fan, and penetrates the electrical board in the thickness direction. Vent (47) to do;
An electrical unit (42) comprising:

  In order to facilitate understanding, the reference numerals of corresponding elements in the examples shown in the drawings and described later are shown in parentheses for reference. The same applies to the following.

  By tilting the fan (48) with the fan support member (49), while introducing outside air outside the electrical unit, cooling the fan by directing the large air volume part of the air volume distribution to the specific electronic component (46) side Since efficiency can be increased, the size of the heat sink can be reduced, leading to space saving. Further, even if a small or low speed fan is used, the same cooling effect can be obtained, so that the cost can be reduced and the noise by the fan can be reduced. Further, since the wind direction by the fan is concentrated on a specific electronic component, the rectifying plate is unnecessary or can be minimized, so that the degree of freedom in arranging the electronic component can be increased. In addition, by providing a gap between the shield case bottom plate (54) and the electrical board (43), and also providing a ventilation port (47) to the back side of the electrical board, cooling of the front side parts and back side parts It is possible to save space while simultaneously performing.

  (2) At least one of the electrical board (43) and the fan support member (49) includes a plurality of the heat sinks (45), the ventilation openings (47), and the fans (48) arranged in the arrangement direction. The electrical unit (42) according to (1), further comprising a mounting hole through which a member for fixing the electrical substrate (43) and the fan support member (49) passes. According to this, since it becomes possible to change the positional relationship of the fans in accordance with the arrangement of the electronic components to be mounted, the degree of freedom of arrangement of the electronic components can be increased. Moreover, the applicable electrical circuit board dimension (length) can be increased.

  (3) The electrical unit (42) according to (1) or (2), further including an adjustment mechanism capable of adjusting the angle of inclination of the fan. Since the angle of the fan can be arbitrarily changed, the direction of the fan's wind can be changed by changing the angle. Depending on the angle of the fan, specific portions can be concentrated and cooled, or a wide range can be cooled, and a current plate can be dispensed with.

  (4) The fan support member (49) has a vertical portion that is fixed to the side wall of the shield case, a horizontal portion that supports the electrical board, and an inclined portion that supports the fan; The electrical unit (42) according to any one of 3). The fan support member 49 can be fixed to the side wall of the shield case by supporting the fan at the inclined portion, supporting the electrical board at the horizontal portion, and vertically at the vertical portion. Since the number of support plates for fixing the electrical board can be reduced, it is possible to improve the assemblability and reduce the cost.

  (5) An image processing apparatus equipped with the electrical unit (42) according to any one of (1) to (4). According to this, the effects described in (1) to (4) above can be obtained in the image processing apparatus.

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

  FIG. 1 shows the appearance of a multi-function full-color digital copying machine MF1 equipped with the main electrical unit 42 of the first embodiment of the present invention. The full-color copying machine is roughly an automatic document feeder (SDF) 10 having an image reading function on the back side of the document, an operation board (not shown), a color scanner 20, a color printer 30, and a paper feed bank 80. Each unit is composed. A local area network (LAN) connected to a personal computer PC is connected to the CPU 3 (FIG. 2), which is a system controller, in the main electrical unit 42.

  The printer 30 includes a transfer unit, and the transfer unit includes a transfer belt 31 that is an endless belt. The transfer belt 31 is wound around three support rollers and one tension roller, and is driven to rotate counterclockwise. Near the tension roller, there is a transfer body cleaning unit that removes residual toner remaining on the transfer belt 31 after image transfer.

  On the transfer belt 31 between one support roller and another support roller, Y (yellow), M (magenta), c (cyan) and k (black) colors are formed along the moving direction. An image forming unit is provided, and there is a transfer roller 33 facing each photoconductor drum 32 in the image forming unit with the transfer belt 31 interposed therebetween. Above the image forming unit, there is a laser exposure unit 34 that irradiates each photoconductor drum of each color photoconductor unit with laser light for image formation. The photosensitive drum 32 is uniformly charged by the charging roller 35, and the laser exposed by the laser exposure unit 34 is projected onto the charged surface by the image signal. The electrostatic latent image generated thereby is developed by the developing device 40 into a toner image. This toner image is transferred to the transfer belt 31.

  Below the transfer belt 31 is a transport belt 39. The conveyor belt 39 transfers the toner image on the transfer belt 31 onto a sheet, that is, a sheet. The sheet on which the toner image is transferred (transfer sheet) is sent out to the fixing device 40 by the transport belt 39. Below the conveying belt 39 and the fixing device 40 is a double-sided drive unit 41 that is a sheet reversing unit that feeds a sheet immediately after an image is formed on the front surface and reverses the front and back to record an image on the back surface.

  When the start switch on the operation board (not shown) is pressed, if there is a document in the automatic document feeder (SDF) 10, it is transported onto the contact glass of the scanner 20 and then there is no document in the SDF 10. Immediately in order to read a manually placed document on the contact glass, the scanner 20 is driven, and the first carriage 21 and the second carriage 22 in the scanner 20 are read and scanned. Then, light is emitted from the light source on the first carriage 21 to the contact glass, and reflected light from the document surface is reflected by the first mirror on the first carriage 21 toward the second carriage 22, and on the second carriage 22. The image is reflected on the mirror 24 and imaged on the CCD 24 as a reading sensor through the imaging lens 23. Based on the image signal obtained by the CCD 24, each color recording data of Y, M, C, K (Bk) is generated.

  Further, when the start switch is pressed, the rotation driving of the transfer belt 31 is started, the image forming preparation of each unit of the image forming apparatus is started, and the image forming sequence of each color image is started. Thus, an exposure laser modulated based on each color recording data is projected onto the photosensitive drum for each color, and each color toner image is transferred onto the transfer belt 31 as a single image by each color image forming process. When the leading edge of the toner image enters the conveyor belt 39, the sheet is fed from the registration roller pair 38, that is, the feeding roller to the transfer belt 39 at a timing so that the leading edge enters the conveyor belt 39. The toner image on the belt 31 is transferred to the paper. A voltage for transferring toner is applied to the transfer belt 31 by a transfer roller 33. The sheet on which the toner image has moved is sent to the fixing device 40, where the toner image is fixed on the sheet.

  Note that the above-described sheet is selectively rotated by driving one of the sheet feeding rollers immediately above the sheet feeding trays (also referred to as sheet feeding stages or cassettes) 71 to 73 of the sheet feeding bank 80, so that the sheet feeding bank 80 has multiple stages. The sheet is fed out from one of the paper feed trays 81 to 83, separated by one separation roller, put into a vertically arranged transport roller unit, transported upward, and guided to the transport path in the printer 30. The conveying roller 37 conveys the paper to the registration roller pair 38 and stops the front end of the sheet abutting against the registration roller pair 38. Then, the registration roller pair 38 and the conveyance roller 37 are rotationally driven at the timing described above to the conveyance belt 39. It will be sent out. It is also possible to feed paper by inserting paper on the right side manual feed tray. When the user is inserting paper onto the manual feed tray, the printer 30 rotates the paper feed roller of the manual feed tray to separate one sheet on the manual feed tray and pull it into the manual feed path. Stop by hitting 38.

  The paper discharged after receiving the fixing process by the fixing device 40 is guided to a discharge roller by a switching claw and stacked on a paper discharge tray (not shown). Alternatively, it is guided to the double-sided drive unit by the switching claw, reversed there and led again to the transfer position, and the image is recorded also on the back surface, and then discharged onto the paper discharge tray by the discharge roller. On the other hand, residual toner remaining on the transfer belt 31 after image transfer is removed by a transfer body cleaning unit (not shown) to prepare for image formation again.

  When a document is placed on the document feeding table 11 and the start switch is pressed, the document on the feeding table 11 is drawn into the SDF 10 by the rotation of the feeding roller 12, and when performing the back side scanning, the back side reading head 13 is used. The back image is read. The surface image is projected onto the CCD 24 and read by the mirrors of the first and second carriages that are stationary while the document passes under the platen 14.

  FIG. 2 shows the configuration of the electrical component of the multifunction function copying machine MF1. The scanner 20 includes a CCD photoelectric conversion element 24, an A / D converter, and a circuit for driving them, and generates RGB 8-bit digital image data from grayscale information obtained by scanning a set original. And output. The read head 13 of the SDF 10 includes a CCD photoelectric conversion element in which pixels are distributed in the document width direction, a member for guiding light at each position in the width direction, an A / D converter, and a circuit for driving them, and passes immediately before the head. It generates and outputs digital image data of 8 bits for each RGB from the density information of the original.

  The first image data processing apparatus 1 performs processing for correcting image reading distortion and converting the digital image data from the scanner 20 and the reading head 13 into image data having a predetermined characteristic format. The conversion of the image data format is a format suitable for receiving image data as an output destination. Output image data formats include monochrome binary, gray scale (monochrome multivalue), sRGB, JPEG, Adobe-RGB data, and others.

  The image data whose data format has been converted by the first image data processing device 1 is sent to the bus control device 2. When the bus control device 2 receives the image data from the first image data processing device 1, the bus control device 2 stores it in the memory 4 via the CPU 3. The image data expanded in the memory 4 may be stored and stored in the disk main body 44 of the HDD device 70 as needed, for example, in preparation for re-output. Next, the image data stored in the memory 4 is sent to the second image data processing device 5 via the CPU 3 and the bus control device 2.

  The bus control device 2 is a data bus control device that exchanges various data such as image data and control commands, and also has a bridge function between a plurality of types of bus standards. In this embodiment, the first image data processing device 1, the second image data processing device 5, the CPU 3 and the HDD device 70 are connected by a PCI-Express bus, and the HDD device 70 is connected to the CPU 3 via the bus control device 2. They are connected by a PCI-Express bus. The disk control board 53 and the disk main body of the HDD device 70 are connected by an ATA bus.

  The second image data processing device 5 is digital image data whose characteristics predetermined by the first image data processing device 1 are unified, and image data input through the line I / F device 25 or the external I / F device 27. On the other hand, image adjustment / processing and image processing suitable for the output destination designated by the user are performed.

  When receiving the CMYK image data from the second image data processing device 5, the bus control device 2 stores the data in the memory 4 via the CPU 3. The CMYK image data stored in the memory 4 is sent to the printer 30 via the CPU 3 and the printer I / F 8. The printer 30 outputs the received CMYK image data to a transfer sheet. That is, an image appears on the paper with a developer.

  The disk main body 44 of the HDD device 70 is a large-sized storage device for storing electronic data that is also used in a desktop personal computer, and mainly stores image processing programs, digital image data, and incidental information of digital image data. . In this embodiment, an ATA bus-connected hard disk standardized by expanding IDE is used.

  The CPU 3 is a microprocessor that controls the entire control of the copying machine MF1, and is the main body of the system controller. The memory 4 stores data to be temporarily exchanged in order to absorb a speed difference when bridging between a plurality of types of bus standards and a processing speed difference between connected components themselves, and the CPU 3 performs the digital image processing. It is a volatile memory that temporarily stores programs and intermediate processing data when controlling the apparatus. Since the CPU 3 is required to perform high-speed processing, the system is activated by a boot program stored in the ROM 7 at normal activation, and thereafter, the processing is performed by a program developed in the memory 4 that can be accessed at high speed.

  When the printer 30 receives the digital image data composed of CMYK, the printer 30 outputs the received image data to the transfer paper using an electrophotographic process using a laser beam. Of course, the process used for output can be arbitrarily selected, and may be an ink jet printer that is often used for personal use in recent years.

  S. B. Reference numeral 14 denotes a chip set used for a personal computer, which is a general-purpose electronic device called South Bridge. A bus bridge function often used for constructing a CPU system mainly including PCI-Express and an ISA bridge is formed as a general-purpose circuit. In this embodiment, the ROM 7 is bridged. The ROM 7 is a memory that stores a program (including boot) when the CPU 3 performs image processing control.

  The operation display device 9 is an interface between the copying machine MF1 and a user, and is composed of an LCD (liquid crystal display device) and a key switch. The operation display device 9 displays various states of the device, operation methods and announcements on the LCD, and keys from the user. Detect switch input. In this embodiment, the CPU 3 is connected via a PCI-Express bus.

  The line I / F device 25 is a device that connects a PCI-Express bus and a telephone line. With this apparatus, the machine MF1 can exchange various data via the telephone line.

  The FAX 26 is a general facsimile machine, and exchanges image data with the digital image processing apparatus via a telephone line.

  The external I / F 27 is a device that connects a PCI-Express bus and an external device. With this device, the machine MF1 can exchange various data with the external device. In this embodiment, a network (Ethernet (registered trademark)) and USB are used for the connection I / F. That is, this machine MF1 can be connected to a network or an external medium (such as an SD card) via the external I / F 27 to send image data to the outside or read image data from the outside.

  The PC 28 is a so-called personal computer, and the user performs various controls and input / output of image data with respect to the machine MF1 via application software and drivers installed in the personal computer.

  The external media 29 is a memory device such as a so-called compact flash (registered trademark) card or SD card, and records various electronic data including image data. The user can transfer image data between the MF1 and the memory device. Input / output (read, write) can be performed.

  The first image data processing device 1 to the ROM 7 and the HDD device 70 and the I / Fs 25 and 27 are mounted on the main substrate 43 which is an electrical substrate of the copying machine MF1. The HDD device 70 includes a fan 45, a temperature sensor 46, and a fan driver 47 that cool the periphery of the disk main body 44.

  Referring to FIG. 1 again, the main electrical unit 42 communicates with an intake port and an exhaust port (not shown) that communicate with the outside of the copying machine MF1, and an exhaust gas (not shown) is provided near the exhaust port. There is a fan (different from 48), and the air discharged from the main electrical unit 42 is discharged out of the copier through the exhaust port. As a result, the air outside the copying machine enters the main electrical unit 42 through the intake port. This exhaust fan is for ventilation of the electrical space where the main electrical unit 42 is located.

  FIG. 3 shows an outline of the inside of the main electrical unit 42. In the shield case 51, an electrical board 43 in which an electric circuit and an electronic device shown in the block of the main electrical unit 42 in FIG. The electrical board 43 is supported by the support plate 50 and the fan support member 49 and is fixed to the shield case 51 with a space for accommodating the surface mount component 44 and serving as a ventilation path between the shield bottom plate 54. The fan support member 49 is formed by integrally forming a vertical portion that is fixed to the right side wall of the shield case 51, a horizontal portion that supports the electrical board 43, and an inclined portion that supports the fan 48 by pressing. The fan 48 is an axial fan, and a part of the air blows against the electronic device 46 to which the heat sink 45 is mounted and the heat sink, but the rest hits the back surface (upper surface in FIG. 3) of the electrical board 43 obliquely. Inclined with respect to the electrical board 43 at a narrow angle (an angle smaller than 90 degrees). Since the fan 48 and the electrical board 43 are supported by the fan support member 49 and the fan support member 49 is fixed to the shield case 51 by screws, the number of support plates for fixing the electrical board to the shield case or box is reduced. It is possible to improve the assembling property and reduce the cost.

  The heat sink 45 is a heat radiating plate made of metal or the like for radiating heat of the electronic component that generates heat. The electronic device 46 is an electronic component soldered to a substrate. The shield case 51 is a metal case that prevents unwanted radiation.

  For ventilation, the axial center (rotating axis) of the fan 48 between the device 46 and the fan 48 to be intensively cooled on the electrical board 43 is closer to the fan side than the position where it intersects the electrical board 43. The opening 47 is open. FIG. 4 shows the upper surface (surface: component surface side) of the electrical board 43 looking down, and FIG. 5 shows the lower surface (solder surface side) of the electrical board 43 looking up.

  The air sucked from the air inlet 52 by the rotation of the fan 48 is blown obliquely to the electrical board 43. Part of the upper left portion of FIG. 3 with respect to the rotational axis of the fan 48 hits the heat sink 45 and the electronic device 46, and the other hits the upper surface of the electrical board 43 and flows to the left along the upper surface. The central part of the strong wind at the lower right side in FIG. 3 with respect to the rotation axis of the fan 48 flows through the opening 47 to the shield bottom plate 54 and flows to the left along the lower surface of the electrical board 43. It flows to the left along the upper surface on the upper surface of the electric circuit board 43. Any air flowing to the left flows out of the case through the exhaust port 53.

  By mounting the fan 48 so as to be inclined with respect to the electric circuit board 43, the wind from the fan 48 can be efficiently applied to the heat sink 45 and the electronic device 46, and the cooling effect can be enhanced as compared with the conventional technology. Further, since the wind flowing from the opening 47 to the lower surface side of the electrical board 43 cools the mounting component 44 on the lower surface side, the upper surface side and the lower surface side of the electrical board 43 are efficiently cooled. If the fan 48 is mounted directly above the device, the outside air cannot be efficiently introduced from the air intake port, so the cooling effect is worsened. Can be limited.

  In general, many electronic components that generate heat are mounted on the upper surface of the electrical board, and surface-mounted components that do not generate much heat are often mounted on the back surface of the substrate. In this embodiment, by mounting the fan 48 at an angle, the outside air introduced from the intake port 52 has a large air volume on the upper surface (component surface side) on which many electronic components that generate heat are mounted. Due to the air flow path to the lower surface passing through the opening 47, the air volume can be reduced on the lower surface of the board (solder surface side) with less heat generation. Therefore, both surfaces of the substrate 43 can be efficiently cooled.

  6 and 7 show an outline of the inside of the main electrical unit 42 of the second embodiment. As shown in FIG. 7, three female screw holes into which a set screw can be screwed are formed in the horizontal portion of the fan support member 52 of the second embodiment that supports the electrical board 43, and the heat sink 45, the opening 47, and the fan 48. Are arranged side by side, that is, in the longitudinal direction of the electrical board 43. FIG. 6A shows a mode in which a set screw passed through one screw hole of the electrical board 43 is screwed into the rightmost female screw hole among the three female screw holes in the horizontal portion. When a set screw that is threaded through the electrical board is screwed into the middle hole among the three female screw holes, the electrical board 43 is placed on the shield case 51 and the fan support member 49 in FIG. ). In this way, the relative mounting position relationship between the electrical board 43 and the fan 48 can be changed. As a result, it is possible to select the fan mounting position according to the arrangement of the electronic components on the electrical board 43, and therefore it is possible to select the position of the fan that maximizes the cooling of the electronic components. This increases the degree of freedom of arrangement of electronic components. In addition, it is possible to attach an electrical board having several lengths (left and right directions in the figure).

  In both the first embodiment and the second embodiment, as shown in FIG. 8, the cooling of the electronic component is maximized by changing the inclination angle of the inclined portion of the fan support member 49 that supports the fan. The air blowing angle can be set. When targeting multiple types of electrical boards, prepare fan support members with fan support ramps with an inclination angle that maximizes the cooling of electronic components corresponding to each type. A fan indicating member having a corresponding inclination angle is selected.

  As shown in FIG. 9, the fan support member 49 of the main electrical unit of the third embodiment includes a continuous body of a vertical portion fixed to the side wall of the shield case and a horizontal portion that supports the electrical board, and an inclined portion that supports the fan. Are connected by a hinge 55 which is a relative rotation means, so that an inclined portion supporting the fan can be rotated. In the present embodiment, it is possible to change the blowing angle of the fan 48 with respect to the electrical board 43 by the relative rotation. In the horizontal portion of the fan support member 49 that supports the electrical circuit board 43, as shown in FIG. 9 (a), an angle fixing metal 56 having a plurality of holes in the vertical direction stands integrally with the horizontal portion. The inclined portion that supports the fan has a pin that can be inserted into one of the plurality of holes. By this insertion, the inclined portion is fixed (locked) to the horizontal portion and cannot be tilted. The inclination angle of the inclined portion changes by inserting the pin into another hole. The fan's air blowing angle can be adjusted.

  Since the air blowing angle of the fan 48 can be changed, when it is desired to concentrate and cool a specific range near the fan on the electric circuit board 43, the fan air blowing angle is set to be narrow and a wide area on the electric circuit board 43 is set. If you want to cool, set the fan's air blowing angle wide. This makes it possible to eliminate the rectifying plate that has been required in the prior art. In this embodiment, by changing the fan blowing angle in accordance with the heat generation amount of the electronic component, it becomes possible to change the air volume for the electronic component, and it is possible to intensively cool the heat generating component. The cooling effect can be increased.

1 is a longitudinal sectional view of a copying machine MF1 equipped with a main electrical unit of a first embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of an electrical component of the copying machine MF1 illustrated in FIG. It is a longitudinal cross-sectional view which shows the outline | summary of the inside of the main electrical equipment unit 42 shown in FIG. It is the perspective view which looked down at the upper surface of the electrical equipment substrate 43 shown in FIG. It is the perspective view which looked up at the lower surface of the electrical equipment substrate 43 shown in FIG. It is a longitudinal cross-sectional view which shows the outline | summary inside the main electrical equipment unit 42 of 2nd Example, (a) shows the aspect which has arrange | positioned the electrical equipment board | substrate 43 in the rightmost position, (b) has arrange | positioned in the intermediate position. An aspect is shown. It is the perspective view which looked down at the upper surface of the electrical equipment substrate 43 shown in FIG. Two types of fan support members 49 that can be employed in the first and second embodiments are shown. (A) shows a mode in which the support angle of the fan 48 by the fan support member 49 is small, and (b) shows a mode in which the support angle is large. . The fan support member 49 of 3rd Example is shown, (a) is the side view of the member 49, (b) shows the perspective view looked down from upper direction. It is a longitudinal cross-sectional view which shows typically the ventilation direction and air volume distribution of the axial flow fan 48. FIG. It is a longitudinal cross-sectional view which shows the outline | summary of the conventional cooling mechanism, (a) shows the aspect of the upper surface cooling of an electrical equipment board | substrate, (b) shows the aspect of the upper and lower surface cooling of an electrical equipment board | substrate. It is a longitudinal cross-sectional view which shows the outline | summary of the cooling mechanism of the electrical equipment unit of the conventional one form.

Explanation of symbols

11: Document feeder 12: Feed roller 13: Back side reading head 14: Platen 21: First carriage 22: Second carriage 23: Imaging lens 24: Reading sensor 31: Transfer belt 32: Photosensitive drum 33: Transfer Roller 34: Laser exposure unit 35: Charging roller 39: Conveying belt 40: Developer 41: Double-sided drive unit 42: Main electrical unit 43: Electrical board

Claims (5)

Shield case;
A plurality of electronic components mounted in the shield case with a gap between the bottom plate of the shield case and at least one of the electronic components mounted with a heat sink;
A fan for air-cooling the electrical board;
A fan support member that supports the fan in an inclined posture so that at least a part of the wind hits the heat sink obliquely with respect to the plane of the electrical board; and
A vent hole that is located between the electronic component on which the heat sink is mounted and the fan on the electrical component board and is in a position where the wind of the fan strikes due to the inclination of the fan;
An electrical unit comprising:   A plurality of mounting holes in which at least one of the electrical substrate and the fan support member is arranged in the arrangement direction of the heat sink, the ventilation port, and the fan and through which a member that fixes the electrical substrate and the fan support member passes; The electrical unit according to claim 1, further comprising:   The electrical unit according to claim 1, further comprising an adjustment mechanism capable of adjusting an angle of the inclination of the fan.   4. The fan support member according to claim 1, wherein the fan support member has a vertical portion that is fixed to a side wall of the shield case, a horizontal portion that supports the electrical board, and an inclined portion that supports the fan. Electrical unit.   An image processing apparatus equipped with the electrical unit according to claim 1.

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