JP2017188543A - Electronic apparatus, and heat radiation structure of electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that can efficiently radiate heat without adding a heat radiation member such as a heat sink and can make a device compact.SOLUTION: An electronic apparatus comprises an enclosure, a first electronic substrate mounted with a member to generate heat, a first substrate module having the first electronic substrate fitted to a first fitting sheet metal, and a second substrate module having a second electronic substrate fixed to a second fitting sheet metal. A component to generate heat on the first electronic substrate is arranged at a position opposite to the first fitting sheet metal, and abuts on the first fitting sheet metal through a heat conduction member, the first substrate module is arranged on a mount surface side of the enclosure, and a second substrate module is stood on the first substrate module, the first fitting sheet metal and the second fitting sheet metal being made to abut on each other directly or through the heat conduction member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic device that can efficiently dissipate heat from an electronic component that generates heat.

  As an example of an electronic device, an image reading apparatus having an automatic document feeder (ADF) is known. Such an image reading apparatus reads a document fed from the ADF while conveying the document at a constant speed with the image reading unit fixed. This reading method only has to move the document in a fixed direction at a constant speed, and therefore has an advantage that the size can be reduced as compared with the case of reading the document while moving the image reading unit with the document fixed.

  Among image reading apparatuses, there is a network connection type image reading apparatus that is connected to a network and can convert an image read in the image reading apparatus into an electronic file and send it to the network. The network connection type image reading apparatus does not require an external control device such as a personal computer for controlling the image reading apparatus, and has an advantage that reading processing can be performed by the apparatus alone.

  Such a network-connected image reading apparatus requires an additional circuit for performing an operation for converting the read image into an electronic file, which was performed by an external control device in the conventional image reading apparatus, in the image reading apparatus. Become. The work performed by the added circuit has a large processing load and is realized by incorporating a kind of personal computer in the image reading apparatus. Accordingly, power consumption is increased as compared with a conventional image reading apparatus, and cooling of electronic components and the apparatus is a problem.

  As a heat dissipation mechanism for cooling, there are a forced air cooling method using a fan, a heat diffusion method using a heat pipe, and the like. A technique for simplifying the structure using these has also been studied (see Patent Document 1). However, since a certain amount of space is required for cooling with a fan, a heat pipe, and a heat sink, it is not suitable for downsizing the apparatus.

JP 2013-222275 A

  It is desired to cool parts in the apparatus by providing a heat dissipation mechanism for efficient heat dissipation.

In view of these points, the present invention
A housing,
A first electronic board mounted with a member that generates heat;
A first board module in which the first electronic board is attached to a first mounting sheet metal;
A second board module that fixes the second electronic board to the second mounting sheet metal,
The component with heat generation on the first electronic board is disposed at a position facing the first mounting sheet metal, and is in contact with the first mounting sheet metal via a heat conducting member,
The first board module is disposed on the mounting surface side of the housing, the second board module is erected on the first board module, and the first mounting sheet metal and the second mounting sheet metal Is directly or via a heat conducting member.

  According to the present invention, it is possible to efficiently dissipate heat by widening the heat radiation area, and the second sheet metal is arranged in an upright state with respect to the mounting surface of the housing, so that heat radiation can be improved by natural convection. In addition, since the first electronic substrate and the second electronic substrate are configured in two pieces and the mounting plate of the first electronic substrate and the mounting plate of the second electronic substrate are arranged in a substantially vertical state, the apparatus is downsized. It becomes possible.

1 is a schematic diagram of an image reading apparatus according to an embodiment of the present invention. The block diagram of the control unit which concerns on one Embodiment of this invention. 1 is a schematic diagram of a control unit of an image reading apparatus according to an embodiment of the present invention. 1 is a schematic diagram of a control unit of an image reading apparatus according to an embodiment of the present invention. The board | substrate arrangement | positioning schematic which concerns on one Embodiment of this invention. The board | substrate arrangement | positioning schematic which concerns on one Embodiment of this invention. The board | substrate arrangement | positioning schematic which concerns on one Embodiment of this invention.

(First embodiment)

Hereinafter, with reference to drawings, it explains in detail based on an embodiment of the invention.
<Device configuration>

  FIG. 1 is a schematic diagram of an image reading apparatus as an example of an electronic apparatus according to an embodiment of the present invention.

  The image reading apparatus shown in FIG. 1 is an apparatus that conveys one or a plurality of conveying media S stacked on a mounting table 1 one by one into the apparatus along a route RT, reads the image, and discharges the image onto a discharge tray 2. is there. The reading medium S to be read is, for example, a sheet such as OA paper, a check, a check, a business card, or a card, and may be a thick sheet or a thin sheet. Examples of the cards include an insurance card, a driver's license, and a credit card. The transport medium S also includes a booklet such as a passport. When targeting a booklet, a holder (not shown) can be used. By storing the booklet in a spread state in the holder and placing it on the mounting table 1, the booklet is transported together with the holder and the image can be read.

<Feed>
A first transport unit 10 is provided as a feeding mechanism that feeds the transport medium S along the route RT. In the case of this embodiment, the first transport unit 10 includes a feed roller 11 and a separation roller 12 disposed to face the feed roller 11, and sequentially transports the transport medium S on the mounting table 1 one by one in the transport direction D1. Transport.

<Driver>
A driving force is transmitted to the feed roller 11 from the driving unit 3 such as a motor through the transmission unit 5 and is rotationally driven in the direction of the arrow in the drawing (the forward direction in which the transport medium S is transported along the path RT). The transmission unit 5 is, for example, an electromagnetic clutch, and interrupts the driving force from the driving unit 3 to the feed roller 11.

<Separation structure>
The separation roller 12 disposed to face the feed roller 11 is a roller for separating the transport medium S one by one, and is in pressure contact with the feed roller 11 with a constant pressure. In order to secure this pressure contact state, the separation roller 12 is provided so as to be swingable and is urged to the feed roller 11. The separation roller 12 is driven to rotate in the direction indicated by the solid line arrow (the direction opposite to the forward direction of the feed roller 11) when the driving force is transmitted from the driving unit 3 via the torque limiter 12a.

  Since the driving force transmission is restricted by the torque limiter 12a, the separation roller 12 rotates in a direction (indicated by a broken arrow) along with the feed roller 11 when contacting the feed roller 11. As a result, when a plurality of transport media S are transported to the pressure contact portion between the feed roller 11 and the separation roller 12, two or more transport media S are blocked so that they are not transported downstream except one. .

  In the present embodiment, the separation roller 12 and the feed roller 11 constitute a separation mechanism. However, such a separation mechanism is not necessarily provided, and the conveyance medium S is sequentially fed to the path RT one by one. Any feeding mechanism may be used. In the case where a separation mechanism is provided, instead of the configuration of the separation roller 12, a separation pad that applies a frictional force to the transport medium S is brought into pressure contact with the feed roller 11 so as to have a similar separation operation. May be.

<Conveying structure>
The second transport unit 20 as a transport mechanism on the downstream side in the transport direction of the first transport unit 10 includes a drive roller 21 and a driven roller 22 driven by the drive roller 21 and has been transported from the first transport unit 10. The transported medium S is transported downstream. Driving force is transmitted to the driving roller 21 from the driving unit 4 such as a motor, and the driving roller 21 is rotationally driven in the direction of the arrow in the figure. The driven roller 22 is brought into pressure contact with the driving roller 21 at a constant pressure, and rotates with the driving roller 21. The driven roller 22 may be configured to be biased against the driving roller 21 by a biasing unit (not shown) such as a spring.

  The third transport unit 30 located downstream of the second transport unit 20 in the transport direction includes a drive roller 31 and a driven roller 32 that is driven by the drive roller 31 and is transported from the second transport unit 20. The transport medium S is transported to the discharge tray 2. That is, the third transport unit 30 functions as a discharge mechanism. Driving force is transmitted to the driving roller 31 from the driving unit 4 such as a motor, and the driving roller 31 is rotationally driven in the direction of the arrow in the figure. The driven roller 32 is brought into pressure contact with the driving roller 31 at a constant pressure, and is driven by the driving roller 31. The driven roller 32 may be configured to be biased against the driving roller 31 by a biasing unit (not shown) such as a spring.

  The discharge tray 2 is pivotally supported via a first hinge 101 provided below the image reading device A so as to be rotatable with respect to the image reading device A. Further, the first discharge tray 2a on the first hinge 101 side and the second discharge tray 2b connected to the tip end side thereof are configured, and the second discharge tray 2b is rotatable with respect to the first discharge tray 2a. Is pivotally supported.

<Image reading structure and control>
Here, in the image reading apparatus A of the present embodiment, since the image reading unit 70 disposed between the second transport unit 20 and the third transport unit 30 reads an image, the second transport unit 20 and the second transport unit 20 The three transport unit 30 transports the transport medium S at a constant speed. By always setting the transport speed to be equal to or higher than the transport speed of the first transport unit 10, it is possible to reliably avoid a situation in which the subsequent transport medium S catches up with the preceding transport medium S. For example, in this embodiment, speed control is performed so that the transport speed of the transport medium S by the second transport section 20 and the third transport section 30 is faster than the transport speed of the transport medium S by the first transport section 10. did.

  Even when the transport speed of the transport medium S by the second transport section 20 and the third transport section 30 and the transport speed of the transport medium S by the first transport section 10 are the same, the drive section 3 is controlled. It is also possible to form a minimum interval between the preceding transport medium S and the subsequent transport medium S by intermittently shifting the feeding start timing of the subsequent transport medium S.

<Double feed detection>
When the double feed detection sensor 40 disposed between the first transport unit 10 and the second transport unit 20 is in contact with transport media S such as paper due to static electricity or the like, and passes through the first transport unit 10 ( In other words, this is an example of a detection sensor (a sensor for detecting the behavior and state of the sheet) for detecting this in the case of a double feed state in which the sheets are conveyed in an overlapping manner. Various sensors can be used as the double feed detection sensor 40, but in the case of the present embodiment, it is an ultrasonic sensor, and includes an ultrasonic transmission unit 41 and a reception unit 42, and is a conveyance medium such as paper. Double feed is detected based on the principle that the attenuation amount of the ultrasonic wave passing through the transport medium S is different between the case where S is transported one by one and the case where S is transported one by one.

<Registration sensor>
The medium detection sensor 50 arranged on the downstream side in the conveyance direction with respect to the double feed detection sensor 40 is located on the upstream side of the second conveyance unit 20 and on the upstream side arranged on the downstream side of the first conveyance unit 10. This is an example of a detection sensor (a sensor for detecting the behavior and state of a sheet). The position of the transport medium S transported by the first transport unit 10, specifically, the position of the transport medium S at the detection position of the medium detection sensor 50. Detect whether the end has reached or passed. As the medium detection sensor 50, various sensors can be used. In the case of this embodiment, the medium detection sensor 50 is an optical sensor, and includes a light emitting unit 51 and a light receiving unit 52, and receives light when the transport medium S reaches or passes therethrough. The transport medium S is detected based on the principle that the intensity (the amount of received light) changes.

  In the case of this embodiment, when the leading edge of the transport medium S is detected by the medium detection sensor 50, the above medium is used so that the transport medium S reaches a position where the double feed detection sensor 40 can detect double feed. The detection sensor 50 is provided on the downstream side in the vicinity of the double feed detection sensor 40. The medium detection sensor 50 is not limited to the optical sensor described above. For example, a sensor (image sensor or the like) that can detect the end of the transport medium S may be used, or a lever-type sensor that protrudes into the path RT. It may be a sensor.

  A medium detection sensor 60 different from the medium detection sensor 50 is disposed on the upstream side of the image reading unit 70. This is an example of a downstream detection sensor disposed downstream of the second transport unit 20 and detects the position of the transport medium S transported by the second transport unit 20. Various media detection sensors 60 can be used. In the case of the present embodiment, the medium detection sensor 60 is an optical sensor similar to the medium detection sensor 50, and includes a light emitting unit 61 and a light receiving unit 62. The transport medium S is detected based on the principle that the received light intensity (received light amount) changes due to arrival or passage. In the present embodiment, the medium detection sensors 50 and 60 are disposed on the upstream side and the downstream side in the transport direction of the second transport unit 20, respectively, but only one of them may be used.

<Image reading unit arrangement>
The image reading unit 70 on the downstream side of the medium detection sensors 50 and 60 is, for example, optically scanned, converted into an electric signal and read as image data, and includes a light source such as an LED, an image sensor, A lens array is provided. In the present embodiment, one image reading unit 70 is disposed on each side of the path RT, and reads the front and back surfaces of the transport medium S. However, only one side of the path RT may be arranged to read only one side of the transport medium S. Further, in the present embodiment, the image reading unit 70 is configured to be opposed to both sides of the route RT. However, for example, the image reading unit 70 may be arranged with an interval in the direction of the route RT.

<Explanation of block diagram>
The control unit 80 will be described with reference to FIG. FIG. 2 is a block diagram of the control unit 80 of the image reading apparatus A.

  The control unit 80 includes a main board 57, an operation unit 83, an image reading control board 53, an actuator unit 85 such as a motor, a sensor unit 87 such as a double feed detection sensor 40, an image reading unit 89 such as an image reading sensor, and an operation unit 83. Composed. Note that the division of the board configuration and the control function of the control unit is not limited to the division as in this example.

  The main board 57 includes a CPU 81, a RAM 82, a ROM 88, and a communication unit 84. The CPU 81 controls the entire image reading apparatus A by developing the control program stored in the ROM 88 in the RAM 82 and executing it. The CPU 81 uses a part of the area of the RAM 82 in order to control the image reading apparatus A.

  The operation unit 83 connected to the CPU 81 of the main board 57 includes, for example, an input device such as a switch and a touch panel and a display device such as an LCD, and the CPU 81 displays a setting menu and device status as an interface to the user. Control display devices. The operation unit 83 receives an operation from the user, notifies the CPU 81 of the operation from the user, and the CPU 81 performs an operation corresponding to the notified operation based on the control program. The operation unit 83 may be a combination of a simple indicator using switches and LEDs.

  The communication unit 84 is an interface that performs information communication with an external device. When an external memory or the like is assumed as an external device, examples of the communication unit 84 include a USB interface and SCSI. Further, assuming that an external device connected to the communication unit is an input device such as a mouse or a keyboard, the communication unit 84 may be a USB interface, a keyboard dedicated interface, or a mouse dedicated interface, for example. The communication unit 84 may be an interface that can be connected to a computer network represented by Ethernet. In addition to the wired communication interface, the communication unit 84 may be a wireless communication interface, or may include both wired communication and wireless communication interfaces. A plurality of interfaces may be provided.

  The image reading control board 53 includes an image reading control CPU 86, a RAM 100, a ROM 101, an actuator control unit 102, and a sensor control unit 103. The image reading control CPU 86 performs image reading control by developing the control program stored in the ROM 101 in the RAM 100 and executing it. A part of the control program of the image reading control CPU 86 may be stored in the ROM 88 of the main board 57, transmitted from the CPU 81 to the image reading control CPU 86 at the time of activation, and expanded into the RAM 100 for execution. .

  The actuator controller 102 is connected to the image reading control CPU 86, and the actuator controller 102 controls the actuator 85 in accordance with the control program of the image reading control CPU 86. The actuator 85 includes the drive unit 3, the drive unit 4, the transmission unit 5, and the like. A sensor control unit 103 is connected to the image reading control CPU 86, and the sensor control unit 103 controls the sensor 87 in accordance with a control program of the image reading control CPU 86. The sensor 87 includes a double feed detection sensor 40 and medium detection sensors 50 and 60. An image reading unit 89 is connected to the image reading control CPU 86, and has a function of processing image data read from the image reading unit 89 and transmitting the image data to the CPU 81.

<Driving by receiving start instruction>
A basic operation of the image reading apparatus A will be described. For example, when receiving a start instruction given to the operation unit by the user, the CPU 81 transmits an image reading start instruction to the image reading control CPU 86 on the image reading control board 53. Upon receiving the image reading start instruction, the image reading control CPU 86 controls the actuator 85, the sensor 87, and the image control unit 89 in accordance with the control program, and the conveying medium S positioned at the bottom of the conveying medium S loaded on the mounting table 1. Are sequentially transported one by one, and image reading is performed. The start instruction may be an instruction output from an external device connected to the image reading apparatus A and received by the communication unit 84 described later.

<Control during double feeding>
In the middle of the conveyance, the conveyance medium S is determined by the double-feed detection sensor 40 to determine whether or not there is a double-feed, and if it is determined that there is no double-feed, the conveyance is continued. If it is determined that there is a double feed, the transport is stopped or the capture of the subsequent transport medium S by the first transport unit 10 is stopped, and the transport medium S in the double feed state is discharged as it is. It may be.

<Reading start according to the output of the registration sensor>
The sensor control unit 103 starts reading the image by the image reading unit 70 of the transport medium S transported by the second transport unit 20 at a timing based on the detection result of the medium detection sensor 60, and reads the read image as an image. The data is received by the reading control CPU 86, temporarily stored in the RAM 100 connected to the image reading control CPU 86, and sequentially transmitted to the CPU 81 of the main board 57. The transport medium S on which the image has been read is discharged to the discharge tray 2 by the third transport unit 30, and the image reading process for the transport medium S is completed. Here, the image reading start timing for the document is set before the leading edge of the document reaches the image reading position of the image reading unit 70.

  In addition, the timing for finishing the image reading of one original is set to be after a predetermined time has elapsed since the trailing edge of the original passes through the image reading position of the image reading unit 70. Thereby, even if the document is skewed in the conveyance path, it is possible to prevent the document area from being lost. That is, the leading edge portion and the trailing edge portion of the document are redundantly read as a peripheral image of the document area including the background, and a margin (background portion of the document) is given to the leading edge side or the trailing edge side of the document. The margin may be automatically given in advance on the image reading apparatus side, or may be arbitrarily set by the user through a setting screen that is a user interface realized by the operation unit 83. Good. The image reading apparatus controls the image reading start timing based on the margin setting information.

<Creation and transmission of electronic image data>
The image data read by the image reading unit 89 is received by the image reading control CPU 86 and reconstructed as an image in the RAM 100. The reconstructed image data is sequentially transmitted to the CPU 81, and the CPU 81 is an electronic image instructed by the user. Image conversion processing is performed so as to be in the data format, and electronic image data is created. During the image reading operation, the electronic image data that has undergone the image conversion process is sequentially stored in the RAM 82. When the user instructs that the reading operation is completed via the operation unit 83, the CPU 81 causes the operation unit 83 through the control application of the image reading apparatus to send a transmission destination of the read electronic image data and a protocol for transmission ( A screen for selecting (Rule) is displayed, and the CPU 81 transmits electronic image data created with the selected protocol (Rule) to the transmission destination selected by the user.

  Here, the CPU 81 performs processing on the image data transmitted from the image reading control unit 86 so as to be in the format of electronic image data instructed by the user. However, this work is a work with a heavy processing burden on the CPU 81. Power consumption increases and heat generation also increases. Therefore, the CPU 81 needs to be cooled.

<Disposition and heat dissipation of electronic board>
The arrangement of the electronic substrate will be described with reference to FIG.
The main board 56, which is a first electronic board mainly including the CPU 81 and the communication unit 84, the image reading control board 53, which is a second electronic board mainly including the image reading control unit 86, and an operation unit 83 (not shown). The operation unit board and other peripheral boards (not shown).

  Here, since the main board 56 and the image reading control board 53 have more functions to be mounted than other electronic boards in the image reading apparatus, the outer size of the board is increased, and the area occupied in the apparatus is increased.

  In addition, the image reading apparatus A is arranged with the conveyance path portion 62 tilted obliquely, and the main board 56 and the image reading control board 53 must be arranged in a space below the conveyance path section 62. The main board 56 includes a CPU 81 that is a member that generates heat.

  Since the CPU 81 generates heat, a heat dissipation mechanism is required. As shown in FIG. 4, the surface of the main board 56 on which the CPU 81 is mounted is disposed so as to face the main board mounting sheet 57, which is the first mounting sheet. A heat conductive sheet 59 as a heat conductive member is inserted between the CPU 81 and the main board mounting metal plate 57 so as to come into contact with both the CPU 81 and the main board 56. The heat generated from the CPU 81 moves to the main board mounting sheet metal 57 via the heat conductive sheet 59.

  It should be noted that a plurality of members with heat generation that require heat dissipation, including the CPU 81, may exist on the main board 56, and there is no limitation on the number of members with heat generation. Further, when there are a plurality of members that generate heat, the number of the heat conductive sheets 59 that are inserted between the member that generates heat and the main board mounting sheet metal 57 may be one. One heat conductive sheet 59 may be inserted between the first attachment metal plates 59. That is, no limitation is imposed on the shape and number of the heat conductive sheets 59. Examples of the material of the heat conductive sheet 59 include silicone rubber, acrylic resin, and carbon fiber sheet.

  The image reading control board 53 is fixed to an image reading control board mounting sheet metal 54 as a second mounting sheet metal. The image reading control board metal plate 54 is arranged so as to be substantially perpendicular to the main board mounting metal plate 57 which is the first mounting metal plate. At this time, the main board mounting sheet metal 57 and the image reading control board sheet metal 54 are brought into contact with each other, and the heat of the main board mounting sheet metal 57 is conducted to the image reading control board sheet metal 54. Note that the main board 56, which is the first electronic board, is interposed between the main board mounting sheet metal 57, which is the first mounting sheet metal, and the image reading control board mounting sheet metal 54, which is the second mounting sheet metal. It may be sandwiched and contacted. In this case, since the heat of the electronic board having a relatively high temperature is directly transmitted to the main board mounting metal plate 57 or the image reading control board metal plate 54 without passing through the CPU 81, the heat dissipation performance can be further improved. That is, any medium that can conduct heat may be sandwiched between the first mounting sheet metal and the second mounting sheet metal, and the contacting method is not limited.

  With this configuration, heat from the CPU 81, which is a component with heat generation, mounted on the main board mounting sheet metal 57, which is the first mounting sheet metal provided at the bottom of the image reading apparatus A, is applied to the first mounting sheet metal. Then, the image is transmitted to the image reading control board metal plate 54 which is a second mounting metal plate which is directly or indirectly abutted so as to stand upright. When the temperature of the first mounting sheet metal rises, the surrounding air heated by the heat radiation of the first mounting sheet metal arranged at the bottom tends to stay at the lower part of the sheet metal, and the first mounting is performed when the temperature of the air rises. The heat dissipation from the sheet metal is dulled, and the heat dissipation of the CPU 81 is reduced. On the other hand, since the second attachment sheet metal is erected with respect to the bottom of the image reading apparatus A by bringing the second attachment sheet metal into contact with the first attachment sheet metal, the temperature of the second attachment sheet metal Rises due to natural convection and rises easily from the periphery of the second mounting sheet metal, so that the heat of the first mounting sheet metal can be effectively radiated.

  An external interface 55 is mounted on the end of the main board 56. The interface 55 is constituted by a connector having a height. As shown in FIG. 3, the image reading control board 53 fixed to the image reading control board mounting metal plate 54 is disposed so as to avoid the interface 55 and to be located inside the housing with respect to the interface 55. As a result, the mounting position of the image reading control board 53 to the image reading control board sheet metal 54 can be made lower than the top of the interface 55, so that the exterior member 61, which is a part of the casing disposed so as to surround them. Can be reduced, which is advantageous for downsizing of the apparatus. In addition, a space can be provided between the image reading control board sheet metal 54 and the exterior member 61, so that the heat radiation effect is improved.

  The main board 56, the main board mounting sheet metal 57, the image reading control board 53, and the image reading control board sheet metal 54 are arranged in a region surrounded by the conveyance path portion 62 and the exterior member 61 of the image reading apparatus A. The exterior member 61 is provided with an opening for accessing the interface 55 on the main board 56.

  With the above configuration, the CPU 81 (member with heat generation) is disposed at a position facing the mounting sheet metal 57 (first mounting sheet metal) 57 of the main board 56, and the heat conduction member is provided between the CPU 81 and the main board mounting sheet metal 57). By inserting / abutting a certain heat conductive sheet 59, it is possible to increase the heat radiation area of the heat generated by the CPU 81 by the main board mounting sheet metal 57 without adding a heat sink, and efficient heat radiation becomes possible. Furthermore, the heat radiation area can be increased by directly or indirectly contacting the attachment sheet metal 54 (second attachment sheet metal) 54 of the image reading control board 53 and the main board attachment sheet metal 57, and more efficient heat radiation. Is possible.

  Further, the height of the mounting sheet metal 54 of the image reading control board 53 is set by making the contact portion of the mounting sheet metal 54 of the image reading control board 53 and the mounting sheet metal 57 of the main board 56 away from the interface 55 of the main board 56. Since it can be lowered, the apparatus can be downsized. Further, avoiding the interface 55, the mounting sheet metal 54 of the image reading control board 53 is erected on the inner side of the end of the mounting sheet metal 57 of the main board 56, and then the mounting sheet metal 57 of the main board 56 and the image reading control are performed. It is also possible to reduce the size by providing a part of the exterior member 61 with the end of the attachment metal plate 54 of the substrate 53 inclined.

As mentioned above, although this invention was demonstrated in detail based on one Embodiment, this invention is not limited to one Embodiment mentioned above.
In the present embodiment, the image reading control board 53 that is the second electronic board and the sheet metal 54 for the image reading control board that is the second mounting sheet metal are the main board 56 that is the first electronic board and the first mounting sheet metal. However, the mounting angle is not necessarily vertical (90 degrees), and the mounting angle is not limited.

<Second embodiment>
In the first embodiment described above, the main board mounting sheet metal 57 that is the first mounting sheet metal is disposed so that the surface on which the CPU 81 that is a member that generates heat on the main board 56 is mounted. In the example described above, the heat conduction sheet 59 is inserted and abutted between the CPU 81 and the main board mounting sheet metal 57, and the heat generated from the CPU 81 is transferred to the main board mounting sheet metal 57 via the heat conduction sheet 59. However, the present invention is not limited to this, and the space between the main board mounting sheet metal 57 and the main board 56 may be narrow in the vicinity of the CPU 81. Hereinafter, an example in which the space between the main board mounting sheet metal 57 and the main board 56 is narrowed in the vicinity of the CPU 81 will be described. Hereinafter, parts different from the above-described first embodiment will be described.

  This will be specifically described with reference to FIG. The main board mounting sheet metal 157, which is the first mounting sheet metal, is mounted on the main board in the vicinity of the position where the CPU 181 which is a member with heat generation on the main board 156, which is the first electronic board, is mounted. The shape of the sheet metal 157 is changed so that it is convex with respect to other locations of the sheet metal, and the space from the main board mounting sheet metal 157 to the main board 156 is narrowed. A heat conductive sheet 159 that is a heat conductive member is inserted into this space so as to contact the CPU 181 and the main board mounting sheet metal 157.

  By making the sheet metal convex, it is possible to reduce the thickness of the inserted heat conductive sheet 159. More specific description will be given with reference to FIG. FIG. 6A shows a state in which the shape of the sheet metal is not changed in the vicinity of the CPU 181, and FIG. 6B shows a state of the present embodiment in which the shape of the sheet metal is formed in the vicinity of the CPU 181. In the example of FIG. 6A, when the thickness of the CPU 181 is L1, and the distance from the main board 156 to the main board mounting sheet metal 157 is L, the thickness L2 of the heat conductive sheet 159 is L−L1. On the other hand, in the example of FIG. 6B, the distance from the main board 156 to the main board mounting sheet metal 157 does not change, but the distance from the main board 156 to the main board mounting sheet metal 157 is reduced in the vicinity of the CPU 181. The main board mounting sheet metal 157 has a convex shape.

  Therefore, in the vicinity of the CPU 181, assuming that the spatial distance L ′ from the main board 156 to the main board mounting sheet metal 157 is L ′ <L. Since the thickness L1 of the CPU 181 does not change, the thickness L2 ′ (= L′−L1) of the heat conductive sheet 159 inserted between the CPU 181 and the main board mounting sheet metal 157 is also thinner than the example of FIG. It becomes possible to do. By reducing the thickness of the heat conductive sheet 159 from L2 to L2 ′, it is possible to increase the rate of heat conduction in the sheet metal having higher heat conductivity than the heat conductive sheet 159, and to improve the overall heat conductivity. .

  With the above configuration, the heat conductive sheet 159 can be thinned, the heat conductivity of the heat conductive sheet 159 is improved, and heat can be efficiently transmitted from the CPU 181 to the main board mounting sheet metal 157 more efficiently. Become.

  The heat conductive sheet 159 only needs to improve the contact between the main board mounting sheet metal 157 and the CPU 181 and is preferably elastic and has a certain thickness.

Further, instead of using the heat conductive sheet 159, a part of the main board mounting sheet metal 157 is projected as much as possible to the CPU 181 side so as to be substantially in contact with the gap, for example, with grease or the like. Also good.
(Third embodiment)

  In the first embodiment and the second embodiment described above, in the image reading apparatus surrounded by the transport unit 62 and the exterior member 61, the main board 56, which is the first electronic board, and the first mounting sheet metal are used for heat dissipation. The arrangement of the main board mounting sheet metal 57 and the image reading control board 53 that is the second mounting board for fixing the image reading control board 53 that is the second electronic board improves the heat radiation effect. Explained. The present invention is not limited to the above configuration, and an exhaust hole may be provided in the upper part of the image reading control board 53 and the image reading control board sheet metal 54. Hereinafter, an example in which an exhaust hole is provided in the upper portion of the image reading control board 53 and the image reading control board sheet metal 54 will be described. Note that parts different from the above-described embodiment will be described.

  Specifically, this will be described with reference to FIG. The image reading control board metal plate 254 to which the image reading control board 253 is attached is attached in a substantially vertical direction so as to contact the main board mounting metal plate 259. At this time, the main board 256, the main board attachment sheet metal 257, the image reading control board 253, and the image reading control board sheet metal 254 are arranged in a manner surrounded by the transport unit 262 and the exterior member 261. The exterior member 261 has an exhaust hole 263. The exhaust hole 263 is provided at a position higher than the uppermost uppermost position of either the image reading control board 253 or the image reading control board sheet metal 254.

  With the above configuration, the heat generated in the apparatus and dissipated by the main board mounting metal plate 257 and the image reading control board mounting metal plate 254 and moved upward by natural convection is used for the exhaust provided in the exterior member 261. The holes 263 are discharged outside the apparatus without being confined to the inside of the apparatus (particularly around the sheet metal), and the heat dissipation effect is further enhanced.

  The exhaust holes 263 provided in the exterior member 261 are not particularly limited in terms of the number of holes, the shape of the holes, the arrangement of the holes, and the like, and are located at higher positions in the space surrounded by the conveyance path 262 and the exterior member 261. Providing an effect by providing.

More preferably, by providing an exhaust hole below the mounting table 1, it is possible to prevent intrusion into the image reading apparatus A from the exhaust hole 261 when dust, water droplets, or the like descend from above.
(Fourth embodiment)

  Further, as shown in FIG. 5C, an exhaust fan 364 that creates an air flow from the inside of the apparatus to the outside of the apparatus through the exhaust hole 363 is used in order to force exhaust through the exhaust hole 363. It may be provided inside the apparatus. Further, the exhaust fan 364 may be attached to the outside of the exterior member 361 as long as it can create an air flow from the inside of the apparatus to the outside of the apparatus through the exhaust hole 363. The exhaust fan 364 may continue to rotate while the image reading apparatus A is operating, and the rotation and stop timing, the number of rotations, and the like may be controlled according to the temperature in the apparatus. That is, the control method for the exhaust fan is not limited.

With the above configuration, the air inside the apparatus is forcibly exhausted, so the heat conducted through the main board mounting sheet metal 357 and the image reading control board mounting sheet metal 354 is forcibly discharged outside the apparatus. , Heat dissipation effect is enhanced. Further, the image reading control board mounting sheet metal 354 is disposed inside the housing so as to avoid the connector of the interface 355 on the main board 356, so that the image reading control board mounting sheet metal 354 and the exterior member 361 are disposed. A space is formed. An air flow is generated by exhaust in this space, and the heat dissipation effect can be enhanced by the air flow.
(Fifth embodiment)

  Further, as shown in FIG. 4D, an intake hole 465 may be provided at a position lower than the main board mounting sheet metal 457. By providing the intake hole 465, it becomes easy to create an air flow in the apparatus.

With the above configuration, the air flow from the suction hole 465 to the surface of the main board mounting sheet metal 457 and the surface of the image reading control board mounting sheet metal 454 is generated in the apparatus, and the air flow to the exhaust hole 463 is generated, which is more effective. Heat dissipation. Note that the number of holes, the shape of the holes, the arrangement of the holes, and the like are not particularly limited, and the intake holes are not limited to the main board mounting sheet metal 457 in the space surrounded by the conveyance unit 462 and the exterior member 461. The effect is produced by providing it at a lower position. Further, an intake fan (not shown) may be provided so as to forcibly take in air from the outside of the apparatus toward the inside of the apparatus. It is sufficient to have a certain amount of air as an intake fan to be placed in conjunction with a heat dissipation structure using sheet metal, and a relatively small size can be used. it can. At that time, air taken in from outside is blown to a heat exchanging portion provided by extending a part of the image reading control board mounting metal plate 454 and the air exchanged with the image reading control board mounting metal plate 454 is exhausted. You may comprise so that it may discharge | emit from the hole 463 for use. With this configuration, it is possible to efficiently dissipate heat using the heat exchange part like a heat sink.
(Sixth embodiment)

  In the second embodiment described above, an example has been described in which the heat generated from the CPU 81 is moved to the main board mounting sheet metal 157 and the image reading control board mounting sheet metal 154 via the heat conductive sheet 159. However, the present invention is not limited to this, and a wiring pattern on the main board 156 on which the CPU 181 is mounted may be additionally used as a heat transfer path, and the pattern may be used as a contact portion with the main board mounting metal plate 57. In the vicinity, many holes for interlayer connection connected to the pattern may be provided in a concentrated manner, and heat may be transferred to the main board mounting metal plate 57 through the abutting portion.

  Specifically, this will be described with reference to FIG. The wiring pattern of the main board 556 is formed of a conductor having good thermal conductivity, for example, copper foil. There are a plurality of wiring patterns of the main substrate 556. For example, power supply patterns such as the ground pattern 590 are generally wired so as to have a large area, and in the case of a multilayer substrate, they are wired on the inner layer. A part of the heat generated from the CPU 581 is also transmitted to the main substrate 556 via a connection portion between the CPU 581 and the main substrate 556, for example, a solder ball. The heat transmitted to the main board 556 is conducted into the board through the ground pattern 590 in the main board having good thermal conductivity. Here, the main board 556 is brought into contact with the main board mounting sheet metal 557 at the contact portion 592. The ground pattern 590 is disposed around the contact portion 592. A plurality of holes, for example, via holes 591 connecting the ground pattern 590 wired in the inner layer and the ground pattern 590 disposed around the contact portion 592 are provided in a concentrated manner. Thus, the heat conducted through the inner layer ground pattern 590 is conducted to the contact portion 592 through the via hole 591 and then conducted to the main board mounting sheet metal 557.

  With the above-described configuration, the heat generated from the CPU 581 is transferred from the surface of the CPU 581 to the main board mounting plate 557 via the heat conductive sheet 559, the pattern of the main board 556, the main board 556, and the main board 556. By providing two paths that conduct to the main board mounting metal plate 557 via via holes 591 provided concentrated on the contact portion 592 of the board mounting metal plate 557, the heat generated in the CPU 581 can be more effectively generated. This can be transmitted to the main board mounting sheet metal, and the heat dissipation effect can be enhanced.

  Note that the wiring pattern for conducting heat is not limited to the ground pattern, and any wiring pattern may be used. However, the wiring pattern is preferably made of metal having good thermal conductivity, for example, a copper foil. Is done. Further, the contact portion 592 is not limited to the direct contact between the main board 556 and the main board mounting sheet metal 557. For example, a heat conductive material is inserted to contact the main board 556 and the main board mounting sheet metal 557. You may contact.

A image reading device S transport medium 1 mounting table 2 discharge tray 2a first discharge tray 2b second discharge tray 3, 4 drive unit 5 transmission unit 10 first transport unit 11 feed roller 12 separation roller 12a torque limiter 20 second transport unit 21 driving roller 22 driven roller 30 third conveyance unit 31 driving roller 32 driven roller 40 double feed detection sensor 50, 60 medium detection sensor 51 light emitting unit 52 light receiving unit 53, 153, 253, 353, 453 image reading control board 54, 154 254, 354, 454 Image reading control board mounting plate 55, 155, 255, 355, 455 Interface 56, 156, 256, 356, 456, 556 Main board 57, 157, 257, 357, 457, 557 For main board Mounting sheet metal 59, 159, 259, 359, 459, 559 heat conduction sheet 61, 161, 261, 361, 461 Exterior member 62, 162, 262, 362, 462 Transport unit 70 Image reading unit 80 Control unit 81, 181, 281, 381, 481, 581 CPU
82, 100 RAM
83 Operation unit 84 Communication unit 85 Actuator 86 Image reading control unit 87 Sensor 88, 101 ROM
89 Image reading unit 102 Actuator control unit 103 Sensor control unit 263, 363, 463 Exhaust hole 364 Exhaust fan 465 Intake hole 590 Ground pattern 591 Via hole 592 Abutting part

Claims (8)

A housing,
A first electronic board mounted with a member that generates heat;
A first board module in which the first electronic board is attached to a first mounting sheet metal;
A second board module that fixes the second electronic board to the second mounting sheet metal,
The component with heat generation on the first electronic board is disposed at a position facing the first mounting sheet metal, and is in contact with the first mounting sheet metal via a heat conducting member,
The first board module is disposed on the mounting surface side of the housing, the second board module is erected on the first board module, and the first mounting sheet metal and the second mounting sheet metal An electronic device characterized in that a contact is made directly or via a heat conducting member. The first electronic board has an interface part with the outside in the vicinity of the end part,
2. The electronic apparatus according to claim 1, wherein a place where the first board module and the second board module are brought into contact with each other is a position avoiding the interface portion with the outside.   The first mounting sheet metal has a convex shape in which a distance from the first electronic substrate is shortened at a position facing a member with heat generation on the first electronic substrate. The electronic device according to claim 2.   The said 2nd board | substrate module is standingly arranged in T shape except the edge part of said 1st board | substrate module with respect to said 1st board | substrate module. Item 1. An electronic device according to item 1.   The electronic device according to claim 1, wherein the component that generates heat is a CPU that controls the electronic device main body.   6. The electronic apparatus according to claim 1, wherein one or a plurality of first holes are provided at a position higher than an upper end of the second substrate module in the housing. .   The electronic device according to claim 6, wherein a second hole portion having one or a plurality of holes is provided at a position lower than the first mounting sheet metal in the housing. The first electronic board has a metal pattern with a wide wiring area,
A plurality of holes for connecting the layers of the first electronic substrate connected to the metal pattern having a large wiring area are provided at the contact portion of the first electronic substrate that contacts the first mounting sheet metal. The electronic apparatus according to claim 1, wherein the electronic apparatus is characterized in that: