JP6508076B2 - Document reader and control unit - Google Patents

Description

  The present invention relates to an original reading apparatus for reading a sheet and a control unit.

  There is known an original reading apparatus which separates one of a plurality of stacked sheets, conveys the separated single sheet, and reads an original described on the sheets. In this document reading apparatus, for example, the circuit board may be shielded by a metal plate in order to prevent electromagnetic noise from being emitted to the outside from the control IC of the circuit board. As a technique for suppressing the emission of electromagnetic waves to the outside, Patent Document 1 receives a circuit board provided with an electronic circuit with a receiving tool, covers the receiving tool with a lid, and on the inner wall of the receiving tool and the lid Each discloses an electric part to which a shielding material using a low magnetic permeability material is applied. In this electric part, the circuit board is covered with a shield material without a gap.

JP, 2005-106442, A

  The circuit board of the document reading apparatus is provided with a harness connector for connecting to another substrate or a motor, or a connector of an interface such as USB (Universal Serial Bus) (registered trademark) or LAN. Therefore, there is a problem that it is difficult to cover the circuit board with a shield material without a gap as in the electrical component described in Patent Document 1. Further, in this document reading apparatus, with the speeding up of the clock signal for driving the control IC of the circuit board, for example, there is a concern about the emission of the electromagnetic wave causing the electromagnetic noise in the high frequency band near 1 Ghz.

  An object of the present invention is to provide a document reader and a control unit capable of suppressing the emission of an electromagnetic wave causing electromagnetic noise to the outside.

  A document reading apparatus according to an aspect of the present invention includes a conveyance unit including a motor, a reading device that reads a sheet conveyed by the conveyance unit, and a control unit that controls the conveyance unit and the reading device. The control unit includes a planar circuit board, a control IC provided on the circuit board, a first shield plate extending along one side of the circuit board and facing the one side, and the circuit board Of the second shield plate extending along the other side of the second side facing the other side, an end of the first shield, and a portion of the gap between the first side of the second shield And a magnetic sheet which does not block the other part.

  According to the document reading device of this aspect, the magnetic material that partially covers the gap between the one end of the first shield plate and the one end of the second shield plate from the electromagnetic wave generated from the control IC provided on the circuit board The sheet suppresses the release to the outside.

  In the document reading device according to this aspect, the circuit board may have a plurality of sides, and the magnetic material sheet may be disposed at a position facing the side closest to the control IC among the plurality of sides. In this case, the document reading apparatus can suppress the electromagnetic wave by the magnetic sheet at a position closer to the control IC.

  In the document reading device according to this aspect, the magnetic material sheet includes a first magnetic material sheet and a second magnetic material sheet laminated on the first magnetic material sheet, and the second shield plate is formed at one end. It may be interposed between the first magnetic sheet and the second magnetic sheet. In the document reading device in this case, since the gap is closed in a state in which the first magnetic sheet and the second magnetic sheet are stacked, the electromagnetic wave suppression performance is improved. Since the magnetic material sheet sandwiches the second shield plate at one end, it does not easily come off the second shield plate.

  In the document reading device according to the aspect, the housing includes the control unit, one end of the magnetic sheet is fixed to the second shield plate, and the magnetic sheet extends from the one end of the magnetic sheet. An elastic member is provided in contact with the magnetic sheet and the inner wall of the housing. In this case, in the document reading apparatus, the magnetic material sheet can be pressed and closed in the gap between one end of the first shield plate and one end of the second shield plate by the elastic member. Since the elastic member is not fixed to the first shield plate, the first shield plate can be easily removed.

  In the document reading apparatus according to the aspect, the first shield plate extends from the one end of the first shield plate in a direction approaching the second shield plate and is separated from the one end of the second shield plate by a predetermined distance An extending portion is provided, and the gap is present between the extending portion of the first shield plate and the one end portion of the second shield plate, and the magnetic material sheet is extended by the elastic member. It may be pressed against the part to close the gap. In this case, in the document reading apparatus, the magnetic material sheet can be pressed against the extending portion by the elastic member to close the gap.

  In the document reading device according to the aspect, the harness connected to the outer periphery of the circuit board is provided, and the magnetic material sheet is disposed at a position not overlapping the harness in the direction from the magnetic material sheet to the control IC. May be In this case, in the document reading apparatus, the magnetic material sheet can close the gap formed at the position where the harness is not provided.

  In the document reading device according to this aspect, the harness includes a first harness connected to the reading device and a second harness connected to the transport unit, and the first harness and the second harness are Among the sides of the circuit board, the sides may be disposed along a side different from the side facing the magnetic material sheet. In this case, in the document reading apparatus, a magnetic sheet is provided opposite to the side where the harness is not provided, and on different sides, a harness for the reading device and a harness for the conveyance unit are provided. The emission of electromagnetic waves can be suppressed by these.

  A control unit according to a second aspect of the present invention is a reading device for reading a sheet conveyed by a conveyance unit and a control unit for controlling the conveyance unit, the control unit provided on a planar circuit board and the circuit board An IC, a first shield plate extending along one side of the circuit board and facing the one side, and a second shield extending along the other side of the circuit board and the other side The magnetic sheet includes a plate, an end of the first shield plate, and a part of a gap between the end of the second shield plate and an end of the second shield plate. In this control unit, electromagnetic noise generated from the control IC provided on the circuit board is electromagnetic noise due to the magnetic material sheet partially closing the gap between one end of the first shield plate and one end of the second shield plate. It is possible to suppress the emission of the electromagnetic wave to the outside of the control unit.

FIG. 1 is a cross-sectional view showing an entire configuration of a document reading device 1; FIG. 6 is a bottom view of the document reading device 1 with the paper discharge tray 18 removed. FIG. 6 is a bottom view of the control unit 2; FIG. 5 is a plan view of the circuit board 5; 5 is a rear view of the control unit 2. FIG. 5 is a bottom view of the first shield plate 21. FIG. 5 is a front view of a first shield plate 21. FIG. 5 is a plan view of a second shield plate 31. FIG. 5 is a rear view of a second shield plate 31. FIG. FIG. 2 is a front view of a control unit 2; FIG. 6 is a right side view of the control unit 2; 5 is a left side view of the control unit 2. FIG. 5 is a development view of a magnetic sheet 70. FIG. It is a fragmentary sectional view of control part 2 and the 1st case which show the pasting state of magnetic material sheet 70 to the 2nd shield board 31. As shown in FIG. FIG. 2 is a block diagram showing an electrical configuration of the document reading device 1;

  Embodiments of the present invention will be described with reference to the drawings. The schematic configuration of the document reading device 1 will be described with reference to FIG. The upper side, the lower side, the left side, the right side, the front side and the rear side of FIG. 1 are respectively the upper side, the lower side, the front side, the rear side, the right side and the left side of the document reading device 1. In the following description, when describing the rotation direction of the components of the document reading device 1, the rotation direction when the document reading device 1 is viewed from the right will be described.

[1. Physical Configuration of Document Reader 1]
As shown in FIG. 1, the document reading device 1 is a sheet feed scanner having a function of conveying a sheet-like document and configured to be able to read both sides of a document to be conveyed. The document reading device 1 includes a housing 10, a sheet feed tray 16, and a sheet discharge tray 18.

  The housing 10 internally defines a transport area 20 in which the sheet is transported along the transport direction. The housing 10 has a first housing 11 and a second housing 12. The shape of each of the first housing 11 and the second housing 12 is box-like. The first housing 11 forms the lower part of the housing 10. The second housing 12 overlaps the first housing 11 from the upper side, and forms an upper portion of the housing 10. The transport region 20 is formed between the first housing 11 and the second housing 12 in the vertical direction. The transport area 20 corresponds to an area through which a document passes in the process of the document reading apparatus 1 transporting a document and reading an image. The conveyance area 20 is connected to the outside of the housing 10 by the sheet feed port 10A and the sheet discharge port 10B. The transport region 20 is defined between the upper surface 11A of the first housing 11 and the lower surface 12A of the second housing 12. In other words, the document is conveyed from the paper feed port 10A to the paper discharge port 10B, passing between the upper surface 11A and the lower surface 12A. The second housing 12 is connected rotatably (that is, can be opened and closed) with respect to the first housing 11 about an axis extending in the left-right direction in the vicinity of the sheet discharge outlet 10B.

  The transport direction generally corresponds to a diagonal up-down direction (i.e. forward diagonal down and aft diagonal up). However, since the transport direction is a direction along the transport area 20, it may not be defined as a linear direction. That is, according to the position in the conveyance area 20, the conveyance direction may change the relationship of the orientation with respect to the front, rear, top, bottom, and left and right. In the transport direction, the direction toward the sheet feed port 10A in the transport area 20 is referred to as "upstream". Of the transport direction, the direction toward the sheet discharge outlet 10B in the transport area 20 is referred to as "downstream". As shown in FIG. 1, in a plane orthogonal to the left-right direction, a direction from the transport region 20 toward the first housing 11 is referred to as a “first direction” among the directions orthogonal to the transport direction. The first direction substantially coincides with the direction from the second housing 12 toward the first housing 11 among the directions orthogonal to the top surface 11A of the first housing 11. Among the directions orthogonal to the transport direction, the direction from the transport area 20 toward the second housing 12 is referred to as a “second direction”. In the second direction, as shown in FIG. 1, when the second housing 12 is closed with respect to the first housing 11, the first housing 11 is one of the directions orthogonal to the lower surface 12A of the second housing 12. And the direction from the second housing 12 substantially.

  The paper feed tray 16 extends rearward and obliquely upward from the rear side of the paper feed port 10 </ b> A in the first housing 11. The paper feed tray 16 has a substantially plate shape. One or more originals are placed on the upper surface of the paper feed tray 16. The original of this example is thin paper or thick paper of A4 size, letter size or the like. In the following description, a document is referred to as a sheet.

  The discharge tray 18 can be stored in the lower part of the first housing 11. The sheet discharge tray 18 is pulled forward from the stored state shown in FIG. 1 and used in an expanded state. When the sheet discharge tray 14 is pulled out from the lower part of the first housing 11, the sheet discharge tray 14 extends forward from the lower side of the sheet discharge port 10 </ b> B of the first housing 11. The discharge tray 18 has a substantially plate shape. An upper surface of the sheet discharge tray 18 receives a sheet discharged to the outside of the housing 10 from the sheet discharge outlet 10B.

  As shown in FIGS. 1 and 2, the first housing 11 includes a paper feed roller 41, a conveyance roller 91, a first reading unit 93, and a conveyance roller 92. The paper feed roller 41, the conveyance roller 91, the first reading unit 93, and the conveyance roller 92 are sequentially arranged along the conveyance area 20 from the upstream to the downstream in the conveyance direction. The upper surfaces of the paper feed roller 41, the conveyance roller 91, and the conveyance roller 92 protrude above the upper surface 11A of the first housing 11 (the second direction).

  The paper feed roller 41 rotates about an axis 42 extending along an axial direction intersecting the transport direction. In the present example, the axial direction coincides with the left and right direction. At least a portion of the sheet feeding roller 41 is exposed to the conveyance area 20. The paper feed roller 41 has a cylindrical shape. A plurality of linear recesses extending in the left-right direction are provided on the outer peripheral surface of the sheet feeding roller 41. The shaft 42 is rotatably supported by the first housing 11. The shaft 42 rotates in response to the rotation of a first motor 73 (see FIG. 15) described later. The paper feed roller 41 rotates counterclockwise in response to the rotation of the shaft 42. A part of the paper feed roller 41 (for example, an outer peripheral portion located at the upper end of the paper feed roller 41) protrudes toward the conveyance region 20. A one-way clutch (not shown) is provided between the paper feed roller 41 and the shaft 42. The one-way clutch allows the paper feed roller 41 to idle counterclockwise with respect to the shaft 42.

  The transport rollers 91 and 92 can transport the sheet in the transport direction along the transport area 20 by rotating in contact with the sheet. The transport rollers 91 and 92 have a cylindrical shape. The axes of the transport rollers 91 and 92 extend in the left-right direction. The transport rollers 91 and 92 have the same shape. The shaft member 91 </ b> A extends along the axis of the transport roller 91. The shaft member 92A extends along the axis of the transport roller 92. The shaft members 91A and 92A are each rotatably supported by the first housing 11. The shaft members 91 </ b> A and 92 </ b> A rotate in response to the rotation of the second motor 74. The transport roller 91 rotates counterclockwise in accordance with the rotation of the shaft member 91A. The transport roller 92 rotates counterclockwise in response to the rotation of the shaft member 92A. A part of the conveyance rollers 91 and 92 (for example, an outer peripheral portion located at the upper end of the conveyance rollers 91 and 92) protrudes toward the conveyance region 20.

  The first reading unit 93 is disposed downstream of the conveyance roller 91 in the conveyance area 20 in the conveyance direction. The first reading unit 93 can read an image of a sheet from the lower side of the sheet and generate image data representing the read image. The first reading unit 93 is provided between the conveyance rollers 91 and 92 in the conveyance direction. The first reading unit 93 sets the left and right direction as the main scanning direction. The first reading unit 93 outputs image data representing the read image to the control unit 2 in accordance with an instruction from the control unit 2.

  As shown in FIG. 1, the second housing 12 includes a reverse roller 46, a driven roller 95, a second reading unit 94, and a driven roller 96. The reverse roller 46, the driven roller 95, the second reading unit 94, and the driven roller 96 are sequentially arranged along the transport region 20 from the upstream to the downstream in the transport direction. The lower surfaces of the reverse roller 46, the driven roller 95, the second reading unit 94, and the driven roller 96 respectively project below the first surface 12A of the second housing 12 (first direction).

  The reverse roller 46 contacts the sheet feeding roller 41 in the conveyance area 20. The reverse roller 46 is disposed on the upper side (second direction) with respect to the paper feed roller 41. The reverse roller 46 is cylindrical. The diameter of the reverse roller 46 is smaller than the diameter of the paper feed roller 41. The axis of the reverse roller 46 extends in the left-right direction. The shaft member 47 extends along the axis of the reverse roller 46. The shaft member 47 is rotatably supported by the holder 80. The shaft member 47 rotates in response to the rotation of a second motor 74 described later. The reverse roller 46 is connected to the shaft member 47 via a one-way clutch (not shown). The reverse roller 46 receives a counterclockwise driving force from the shaft member 47. The slip torque of the one-way clutch is set to a value at which it slips due to the frictional force between the sheet and the reverse roller 46 and the frictional force between the sheet feed roller 41 and the reverse roller 46.

  On the other hand, the slip torque of the one-way clutch is set to a value that does not slip due to the frictional force between the sheets. Therefore, when there is no sheet between the sheet feed roller 41 and the reverse roller 46, or when there is only one sheet between the sheet feed roller 41 and the reverse roller 46, the reverse roller 46 is a shaft member It rotates clockwise against the driving force received from 47. On the other hand, when two or more sheets exist between the sheet feed roller 41 and the reverse roller 46, the reverse roller 46 rotates counterclockwise in accordance with the driving force received from the shaft member 47. A portion of the reverse roller 46 (for example, an outer peripheral portion located at the lower end of the reverse roller 46) protrudes toward the transport region 20.

  As shown in FIG. 1, the driven rollers 95 and 96 are cylindrical. The driven roller 95 contacts the upper side of the conveyance roller 91 when the document is not conveyed. The driven roller 96 contacts the upper side of the conveyance roller 92 when the document is not conveyed. The axes of the driven rollers 95, 96 extend in the left-right direction. The driven rollers 95, 96 have the same shape. Each shaft member to which the driven rollers 95 and 96 are fixed is rotatably supported by the second housing 12. The driven roller 95 is biased toward the transport roller 91 by a spring 97. The driven roller 96 is biased toward the transport roller 92 by a spring 98. A portion of the driven rollers 95, 96 (e.g., an outer peripheral portion located at the lower end of the driven rollers 95, 96) protrudes toward the transport region 20.

  The second reading unit 94 is disposed downstream of the conveyance roller 91 in the conveyance area 20 in the conveyance direction. The second reading unit 94 can read an image of a sheet from the upper side of the sheet and generate image data representing the read image. The second reading unit 94 is provided between the driven rollers 95 and 96 in the transport direction. The second reading unit 94 sets the left and right direction as the main scanning direction. The second reading unit 94 outputs image data representing the read image to the control unit 2 in response to an instruction from the control unit 2. As shown in FIG. 15, the first reading unit 93 includes a CIS (Contact Image Sensor) 93A and an AFE (Analog Front End) 93B. The second reading unit 94 includes a CIS 94A and an AFE 94B. The CIS 93A, 94A reads an image of a document and generates an analog image signal. The AFEs 93B and 94B convert the image signals from the CISs 93A and 94A into digital image data, respectively.

[2. Electrical Configuration of Document Reader 1]
The electrical configuration of the document reading device 1 will be described with reference to FIG. As shown in FIG. 15, the document reading device 1 has an operation unit 24, a LAN port 32, a USB (Universal Serial Bus) port 33, a control unit 2, a first motor 73, a second motor 74, A first reading unit 93 and a second reading unit 94 are provided. The operation unit 24 is provided on the upper surface of the second housing 12. The operation unit 24 includes a plurality of operation buttons including a power button and a start button. The operation unit 24 may further include a liquid crystal panel and a touch panel superimposed on the liquid crystal panel. The user can input various instructions via the operation unit 24. The USB port 33 is a port for connecting the document reading device 1 and an external device such as a PC by an interface conforming to the USB standard.

  The control unit 2 can control the first motor 73, the second motor 74, the first reading unit 93, and the second reading unit 94. The control unit 2 includes an ASIC 57 and a LAN controller 58. The ASIC 57 controls the entire document reading device 1. Although not illustrated, the control unit 2 includes a predetermined electric circuit or the like that transmits a drive signal (for example, a drive current) to the first motor 73 and the second motor 74 according to an instruction from the ASIC 57. The CPU internally includes a RAM, a ROM, and the like.

[3. Mechanical structure of control unit 2]
The mechanical structure of the control unit 2 of the document reading device 1 will be described with reference to FIGS. The control unit 2 is a circuit board box formed in a box shape. A circuit board 5 is provided inside the control unit 2. Furthermore, in the control unit 2, a housing is formed by the first shield plate 21 and the second shield plate 31 with the circuit board 5 interposed therebetween. As shown in FIG. 3 and FIG. 4, the circuit board 5 is a flat, horizontally long rectangular printed board in plan view. The circuit board 5 includes a front side 55, a right side 53, a left side 54, and a rear side 56. As shown in FIG. 4, an ASIC 57 and a LAN controller 58 are provided on the top surface 52 of the circuit board 5. The ASIC 57 is a control IC that performs operation control of the document reading device 1 and image processing. The LAN controller 58 controls LAN communication. The ASIC 57 is provided closer to the front side 55 and closer to the right side 53 of the circuit board 5. Although not illustrated, the circuit board 5 includes a predetermined electric circuit or the like that transmits a drive signal (for example, a drive current) to the first motor 73 and the second motor 74 according to an instruction from the ASIC 57. As shown in FIG. 2, when the control unit 2 is viewed from the bottom side, the bottom side of the circuit board 5 shown in FIG. 4 opposite to the top surface 52 is the bottom side of the document reading device 1. In this state, the magnetic material sheet 70 described later is disposed at a position corresponding to the front side 55 of the circuit board 5 closest to the ASIC 57.

  Further, as shown in FIG. 2, harnesses 531A to 555A described later are connected to the outer periphery of the lower surface of the circuit board 5. The outer periphery of the circuit board 5 refers to a region closer to any side than the center of the circuit board 5. As shown in FIG. 3, as an example, a connector 551, a connector 552, a connector 553, a connector 554, and a connector 555 are provided on the front side 55 of the circuit board 5. A connector 531 and a connector 532 are provided on the right side 53 side. A connector 541, a connector 542, a connector 543 and a connector 544 are provided on the left side 54 side. As shown in FIG. 5, on the side of the rear side 56, a LAN port 32, a USB port 33, and a jack 35 of an AC adapter are provided. The LAN port 32 is a port for performing wired communication via the LAN between the document reading apparatus 1 and an external device such as a PC (personal computer) connected to the LAN. The USB port 33 is a port for communicating with an external device such as a PC (personal computer) connected to the document reading device 1 according to the USB standard.

  As shown in FIGS. 2 and 3, the connector 551 is connected to a harness 551 </ b> A from a cover sensor (not shown) that detects the open / close state of the housing. Connected to the connector 552 are a harness 552A from a front sensor that detects a sheet placed on the sheet feeding tray 16, and a harness 552B from a rear sensor that detects a sheet position during conveyance. Connected to the connector 553 is a harness 553A from an ultrasonic sensor that detects double feed of sheets. A harness 554A for driving a sensor is connected to the connector 554. A harness 555A from a jam sensor for detecting a sheet jam is connected to the connector 555. The harness 531A from the first reading unit 93 is connected to the connector 531. A harness 532A from a USB connector substrate (not shown) to which a USB memory can be connected is connected to the connector 532. The harness 541A from the second reading unit 94 is connected to the connector 541. A harness 542A from a liquid crystal panel included in the operation unit 24 is connected to the connector 542. A harness 543A from the first motor 73 is connected to the connector 543. A harness 544A from the second motor 74 is connected to the connector 544. That is, the harness 531A connected to the first reading unit 93, the harness 541A connected to the second reading unit 94, the harness 543A from the first motor 73, the harness 544A from the second motor 74, and the USB connector Among the sides of the circuit board 5, harnesses 532A from the board are provided on the right side 53 and the left side 54 which are sides different from the front side 55 opposed to the magnetic material sheet 70 described later.

[4. Structure of first shield plate 21]
As shown in FIG. 6, the first shield plate 21 is provided with a flat portion 210 which is a substantially rectangular shape in plan view. The flat portion 210 includes a front end 220, a rear end 230, a right end 240 and a left end 250. Further, the first shield plate 21 is formed of a metal plate that blocks electromagnetic waves. An example of the material of the first shield plate 21 is iron. As shown in FIG. 7, on the right side of the front end portion 220, there is provided an extending portion 222 extending upward (in a direction toward the second shield plate 31 after assembly of the control unit 2) orthogonal to the flat portion 210. It is done. The extended portion 222 is a rectangular shape in a front view in the horizontal direction. On the right side of the front end portion 220, a recess 221 recessed toward the rear end portion 230 is provided. The recess 221 is a recess for avoiding the harnesses 552A to 555A. On the side of the front end portion 220 of the right end portion 240, a support wall 241 is provided at the upper side, and a fixing portion 242 which protrudes to the right of the upper end portion of the support wall 241 is provided. The fixing portion 242 is provided with a through hole of a screw. As shown in FIG. 11, the rear of the support wall 241 is open. A support wall 251 is provided on the upper side at a corner on the front end portion 220 side of the left end portion 250, and a fixing portion 252 is provided on the upper end portion of the support wall 251 so as to project obliquely leftward. The fixing portion 252 is provided with a through hole of a screw. As shown in FIG. 12, the rear of the support wall 251 is open. Further, the left end 250 is provided with a recess 253 toward the right. The recess 253 is a recess for avoiding the harness 542A. The rear end portion 230 is provided with engaging portions 231 and 232 that engage with the bent portion 332 of the second shield plate 31.

[5. Structure of second shield plate 31]
As shown in FIG. 8, the second shield plate 31 is provided with a flat portion 310 which is a substantially rectangular shape in plan view. The flat portion 310 includes a front end 320, a rear end 330, a right end 340, and a left end 350. The second shield plate 31 is made of a metal plate that blocks electromagnetic waves. An example of the material of the second shield plate 31 is iron. At right and left ends of the front end portion 320, fixing portions 321 and 322 are provided. Each of the fixing portions 321 and 322 is provided with a screw hole. At the right end portion 340, fixing portions 341 and 342 are provided. The fixing portions 341 and 342 are respectively provided with through holes of screws. The left end portion 350 is provided with fixing portions 351 and 352. The fixing portions 351 and 352 are each provided with a through hole of a screw. At the right end of the rear end portion 330, a fixing portion 338 is provided. The fixing portion 338 is provided with a screw hole. A fixing portion 311 is provided at the center of the rear end portion 330 side, and a fixing portion 312 is provided at the left end of the rear end portion 330 side. The fixing portions 311 and 312 are respectively provided with screw holes.

  The rear end portion 330 is provided with a rear panel 331 (see FIG. 9) extending downward (in a direction toward the first shield plate 21 after the control unit 2 is assembled) orthogonal to the flat portion 310. As shown in FIG. 9, the rear panel 331 is a horizontally long, substantially rectangular, and includes a substantially rectangular opening 333, an opening 334, an opening 336, and a security hole 337. As shown in FIG. 5, the opening 333 is for the LAN port 32. The opening 334 is for the USB port 33. The opening 336 is for the jack 35 of the AC adapter. The security hole 337 is for antitheft wire lock. As shown in FIG. 8, the upper end portion of the rear panel 331 is provided with a bent portion 332 extending in the front direction in parallel with the flat portion 310. The bent portion 332 is a horizontally long substantially rectangular shape.

[6. Assembly of control unit 2]
During assembly of the control unit 2, the circuit board 5 is accommodated between the first shield plate 21 and the second shield plate 31. The circuit board 5 is mounted on the fixing portions 311, 312, 338, 321 and 322. The circuit board 5 is fixed to the fixing portion 312 (see FIG. 12) by the screw 245, to the fixing portion 338 (see FIG. 11) by the screw 246, and to the fixing portion 311 by a screw not shown. The engaging portions 231 and 232 of the first shield plate 21 engage with the bent portion 332. The circuit board 5 is sandwiched between the fixing portions 321 and 322 of the second shield plate 31 and the fixing portions 242 and 242 of the first shield plate 21 and is screwed with screws 243 and 244, respectively.

[7. Structure of front and side of control unit 2]
As shown in FIG. 10, a part of the gap 223 between the extension part 222 of the first shield plate 21 on the front surface of the control unit 2 and the second shield plate 31 is closed by a magnetic material sheet 70 described later. In the part, the magnetic material sheet 70 is not blocked. Parts other than the extension part 222 on the front surface of the control unit 2 are released, and the connector 551, the connector 552, the connector 553, the connector 554 and the connector 555 are exposed. As shown in FIG. 11, the right side surface of the control unit 2 is released, and the connectors 531 and 532 are exposed. As shown in FIG. 12, the left side surface of the control unit 2 is released, and the connectors 541, 542, 543, and 544 are exposed.

[8. Structure of Magnetic Sheet 70]
Next, with reference to FIGS. 13 and 14, the structure and fixing method of the magnetic sheet 70 will be described. The magnetic material sheet 70 is a sheet of an electromagnetic shield material made of a magnetic material (for example, ferrite particles) and a resin. The magnetic material sheet 70 is used, for example, to suppress the emission noise from the electronic device over a wide frequency range. The magnetic sheet 70 is flexible and excellent in flexibility. As shown in FIG. 13, the magnetic sheet 70 is, for example, a rectangular sheet in plan view, and an adhesive is applied to one surface. In the longitudinal direction of the magnetic sheet 70, half of the center line 75 is referred to as a first magnetic sheet 71, and the other half is referred to as a second magnetic sheet 72. The first magnetic material sheet 71 includes a stacked unit 71A and a bonding unit 71B. The second magnetic material sheet 72 includes a stacked unit 72A and a bonding unit 72B. As shown in FIG. 14, the laminated portion 71A and the laminated portion 72A are attached to each other with the surfaces coated with the adhesive inside. Therefore, the stacked portion 71A and the stacked portion 72A are stacked. Further, the attaching part 71B is attached to the upper surface of the second shield plate 31, and the attaching part 72B is attached to the lower surface of the second shield plate 31. That is, the second shield plate 31 is sandwiched between the affixing portion 71B and the affixing portion 72B.

  No adhesive is applied to the outside of the laminated portion 71A and the laminated portion 72A of the magnetic material sheet 70 shown in FIGS. 2 and 14. The stacked portion of the magnetic sheet 70 by the stacked portion 71A and the stacked portion 72A is pressed against the extended portion 222 of the first shield plate 21 by the one surface 90A of the elastic member 90. The other surface 90 </ b> B of the elastic member 90 is in contact with the inner wall 11 </ b> B of the first housing 11. The elastic member 90 is formed of, for example, a rectangular parallelepiped sponge or rubber. The elastic member 90 may be attached to the inner wall 11B, or may be attached to the outer surface of the laminated portion 71A of the magnetic material sheet 70. The thickness (the thickness in the front-rear direction shown in FIG. 14) of the elastic member 90 before compression is longer than the distance between the extension portion 222 of the first shield plate 21 and the inner wall 11B of the first housing 11. Therefore, the laminated portion by the laminated portion 71A and the laminated portion 72A of the magnetic material sheet 70 is pressed against the extension portion 222 of the first shield plate 21 by the elastic force of the elastic member 90. In this state, as shown in FIG. 10, a part of the gap 223 between the extended portion 222 of the first shield plate 21 and the second shield plate 31 is a magnetic material in which the stacked portion 71A and the stacked portion 72A are stacked. The body sheet 70 is closed. Further, as shown in FIG. 2, in the direction from the magnetic sheet 70 to the ASIC 57 (that is, the back direction), the magnetic sheet 70 is harnesses 531 A, 532 A, 541 A, 542 A, 543 A, 544 A, 552 A, 553 A , 555A is not placed.

[9. Effect of magnetic sheet 70]
In the document reading device 1, a part of the gap 223 between the extended portion 222 of the first shield plate 21 and the second shield plate 31 is closed by the stacked portion of the magnetic material sheet 70 by the stacked portion 71A and the stacked portion 72A. . Therefore, with the increase in speed of the clock signal for driving the control IC such as the ASIC 57 of the circuit board 5, for example, there is a concern about the emission of electromagnetic waves causing electromagnetic noise in the high frequency band near 1 Ghz. The sheet 70 reduces the emission of electromagnetic waves to the outside. The inventor of the present invention reads the case where the gap 223 is closed with the magnetic material sheet 70, the case where the gap 223 is closed with the copper tape, and the case where the magnetic material sheet 70 or the copper tape is not provided in the gap 223. The emission of 875.0 MHz and 1000.0 MHz electromagnetic waves to the outside was measured in an anechoic chamber using an EMI (Electro Magnetic Interference) receiver. In the measurement, the document reading device 1 was placed on a turntable and rotated by a predetermined angle, and the height of the document reading device 1 was changed to a predetermined height. The distance between the document reader 1 and the antenna of the EMI receiver is 10 m.

  In the following measurement results, the Frequency column is the measured frequency. The value in the Result column is a value obtained by measuring an electromagnetic wave with an EMI receiver. The value in the Limit column is a predetermined electromagnetic wave limit value. The value in the Margin column is a value obtained by subtracting the value in the Result column from the value in the Limit column. That is, it is a margin to the limit value of the electromagnetic wave. The larger the value in the Margin column, the lower the noise. The value in the Height column is the height of the document reading device 1, and the value in the Angle column is the rotation angle from the front of the document reading device 1 by the turntable. Moreover, the measurement measured horizontal polarization and vertical polarization.

磁性体シート７０を使用した場合には、水平偏波の８７５．０ＭＨｚのＭａｒｇｉｎは、６．０ｄｂであり、１０００．０ＭＨｚのＭａｒｇｉｎは、７．８ｄｂである。垂直偏波の８７５．０ＭＨｚのＭａｒｇｉｎは、５．６ｄｂであり、１０００．０ＭＨｚのＭａｒｇｉｎは、５．６ｄｂである。 The measurement results when the gap 223 is closed by the magnetic material sheet 70 are shown in Table 1.

When the magnetic material sheet 70 is used, the 875.0 MHz Margin of horizontal polarization is 6.0 db, and the 1000.0 MHz Margin is 7.8 db. The vertically polarized 875.0 MHz Margin is 5.6 db, and the 1000.0 MHz Margin is 5.6 db.

銅テープを使用した場合には、水平偏波の８７５．０ＭＨｚのＭａｒｇｉｎは、５．１ｄｂであり、１０００．０ＭＨｚのＭａｒｇｉｎは、５．６ｄｂである。垂直偏波の８７５．０ＭＨｚのＭａｒｇｉｎは、６．９ｄｂであり、１０００．０ＭＨｚのＭａｒｇｉｎは、０．１ｄｂである。 Table 2 shows the measurement results when the gap 223 is closed with a copper tape.

When copper tape is used, the 875.0 MHz Margin of horizontal polarization is 5.1 db, and the 1000.0 MHz Margin is 5.6 db. The vertically polarized 875.0 MHz Margin is 6.9 db, and the 1000.0 MHz Margin is 0.1 db.

磁性体シート７０も銅テープも設けない場合には、水平偏波の８７５．０ＭＨｚのＭａｒｇｉｎは、２．９ｄｂであり、１０００．０ＭＨｚのＭａｒｇｉｎは、４．８ｄｂである。垂直偏波の８７５．０ＭＨｚのＭａｒｇｉｎは、０．２ｄｂであり、１０００．０ＭＨｚのＭａｒｇｉｎは、４．９ｄｂである。 Table 3 shows the measurement results in the case where neither the magnetic sheet 70 nor the copper tape is provided in the gap 223.

In the case where neither the magnetic sheet 70 nor the copper tape is provided, the 875.0 MHz Margin of the horizontal polarization is 2.9 db, and the 1000.0 MHz Margin is 4.8 db. The vertically polarized 875.0 MHz Margin is 0.2 db, and the 1000.0 MHz Margin is 4.9 db.

  From the above measurement results, it can be seen that when the gap 223 is closed with the magnetic material sheet 70, the emission of electromagnetic waves at 1000.0 MHz is the smallest. Therefore, it was found that the case where the magnetic material sheet 70 closed a part of the gap 223 is more effective in noise reduction than the case where nothing is provided as compared with the case where the copper tape is used. In addition, the emission of electromagnetic waves at 875.0 MHz is also more effective in reducing noise than in the case where nothing is provided when the gap 223 is closed with the magnetic material sheet 70, except for vertical polarization, as compared with the case where a copper tape is used. It turned out that there was.

[10. Operation of Document Reader 1]
An operation in the case where a plurality of sheets are conveyed by the document reading device 1 and an image is read will be briefly described. A plurality of sheets are placed on the upper surface of the paper feed tray 16 by the user. The control unit 2 rotationally drives the first motor 73 and the second motor 74. The rotational driving force of the first motor 73 is transmitted to the shaft 42 to rotate the sheet feeding roller 41 counterclockwise. The rotational driving force of the second motor 74 is transmitted to the shaft members 91A and 92A to rotate each of the transport rollers 91 and 92 counterclockwise. Until the plurality of sheets reach between the feed roller 41 and the reverse roller 46, the reverse roller 46 rotates clockwise with the feed roller 41. When a plurality of sheets reach between the feed roller 41 and the reverse roller 46, the rotational driving force of the second motor 74 causes the reverse roller 46 to rotate counterclockwise.

  In the above-described state, the sheet feed roller 41 contacts the lowermost sheet of the plurality of sheets moving downstream in the transport direction along the transport region 20 from the first direction. At this time, the sheet is separated from the plurality of sheets by the rotation of the sheet feeding roller 41 and the reverse roller 46. The sheet moves downstream along the transport area 20.

  The conveyance roller 91 contacts the sheet moving along the conveyance area 20 from the lower side, and further conveys the sheet downstream with the sheet interposed between the conveyance roller 91 and the driven roller 95. The sheet moves downstream along the transport area 20. The first reading unit 93 disposed downstream of the conveyance roller 91 reads an image of the lower surface of the sheet in accordance with an instruction from the control unit 2. The second reading unit 94 disposed downstream of the conveyance roller 91 reads an image on the upper surface of the sheet in response to an instruction from the control unit 2. Output signals of the first reading unit 93 and the second reading unit 94 are converted into image data, and are output to the control unit 2.

  The conveyance roller 92 contacts the sheet passing through the first reading unit 93 and the second reading unit 94 from the lower side, and further conveys the sheet downstream with the sheet interposed between the sheet and the driven roller 96. The sheet is discharged from the sheet discharge outlet 10B to the outside of the housing 10 and disposed in the sheet discharge tray 18.

  Even when the document reading apparatus 1 operates as described above, a part of the gap 223 between the extended portion 222 of the first shield plate 21 of the control unit 2 and the second shield plate 31 corresponds to the stacked portion 71A and the stacked portion Since the magnetic material sheet 70 on which 72A is stacked is closed, there is an effect of reducing the noise of the electromagnetic wave at 1000.0 MHz. Further, since the magnetic sheet 70 is only pressed to the extension portion 222 of the first shield plate 21 and not attached, the first shield plate 21 can be easily made at the time of maintenance of the document reading device 1. Can be removed. In addition, the magnetic material sheet 70 is folded back, and the magnetic material sheet 70 in which the lamination portion 71A and the lamination portion 72A are laminated is closed. Since the laminated portion 71A and the laminated portion 72A are laminated to be laminated, the thickness of the magnetic sheet 70 is twice that of the base material, and the electromagnetic wave suppression effect is improved as compared to the case where the magnetic sheet 70 is not laminated. Since the second shield plate 31 is interposed between the affixing portion 71 B and the affixing portion 72 B of the magnetic material sheet 70, the magnetic material sheet 70 does not easily come off the second shield plate 31.

  Since the magnetic material sheet 70 is disposed at a position corresponding to the front side 55 of the circuit board 5 closest to the ASIC 57, the electromagnetic wave can be suppressed at a position closer to the ASIC 57. Since the magnetic material sheet 70 is disposed at a position not overlapping the harnesses 531A to 555A in the direction from the magnetic material sheet 70 to the ASIC 57, the gap 223 which can be provided at a position where the harnesses 531A to 555A are not provided Can be blocked. A harness 531A connected to the first reading unit 93, a harness 541A connected to the second reading unit 94, a harness 543A from the first motor 73, and a harness 544A from the second motor 74 are included in the circuit board 5. Among the sides, they are provided on the right side 53 and the left side 54 which are sides different from the front side 55 facing the magnetic material sheet 70. Therefore, although the harnesses 531A to 555A have an electromagnetic wave suppressing effect, the magnetic material sheet 70 can suppress the emission of the electromagnetic waves from the front side 55 side which is the side on which the harnesses 531A to 555A are not provided.

  In the document reading apparatus 1 described above, the first motor 73, the second motor 74, the sheet feeding roller 41, the reverse roller 46, and the conveying rollers 91 and 92 are examples of the "conveying unit" in the present invention. CIS 93A, 94A is an example of the "reading device" of the present invention. The control unit 2 is an example of the “control unit” in the present invention. The circuit board 5 is an example of the “circuit board” in the present invention. The ASIC 57 is an example of the “control IC” in the present invention. The first shield plate 21 is an example of the “first shield plate” in the present invention. The second shield plate 31 is an example of the “second shield plate” in the present invention. The magnetic sheet 70 is an example of the “magnetic sheet” in the present invention. The gap 223 is an example of the “gap” in the present invention. The first magnetic sheet 71 is an example of the “first magnetic sheet” in the present invention. The second magnetic sheet 72 is an example of the “second magnetic sheet” in the present invention. The first housing 11 is an example of the “housing” in the present invention. The inner wall 11B is an example of the "inner wall" in the present invention. The extended portion 222 is an example of the “extended portion” in the present invention. The harness 531A and the harness 541A are examples of the "first harness" in the present invention. The harness 543A and the harness 544A are examples of the "second harness" in the present invention. The elastic member 90 is an example of the “elastic member” in the present invention. The control unit 2 is an example of the “control unit” in the present invention.

  The document reading apparatus of the present invention is not limited to the above-described embodiment, and various changes may be made without departing from the scope of the present invention.

  For example, the configuration of the document reading apparatus may be changed as appropriate. The magnetic material sheet 70 may be formed by bonding a plurality of cut magnetic material sheets without folding and laminating. For example, two sheets may be attached to each other. Also, one magnetic sheet 70 may be thick. In place of the ASIC 57, the circuit board 5 may be provided with a CPU, a ROM, a RAM, and the like. The document reader may be capable of transporting a sheet-like document. The first motor 73 and the second motor 74 may be motors other than a stepping motor such as a DC motor. The number of motors provided in the document reader may be changed as appropriate. The document reading apparatus 1 may include only one of the first reading unit 93 and the second reading unit 94. The first reading unit 93 and the second reading unit 94 have only the CIS 93A, 94A, and the control unit 2 etc. has a circuit for converting an analog image read by the CIS 93A, 94A into digital image data. It may be

Reference Signs List 1 document reading apparatus 2 control unit 5 circuit board 11 first case 11B inner wall 21 first shield plate 31 second shield plate 41 sheet feed roller 46 reverse roller 57 ASIC
70 magnetic material sheet 71 first magnetic material sheet 72 second magnetic material sheet 73 first motor 74 second motor 90 elastic members 91 and 92 conveyance roller 93 first reading unit 93A CIS
94 2nd reading part 94A CIS
222 Extension part 223 Gap 531A Harness 541A Harness 543A Harness 544A Harness

Claims (8)

A transport unit including a motor,
A reading device that reads a sheet conveyed by the conveyance unit;
And a control unit that controls the transport unit and the reading device.
The control unit
Planar circuit board,
A control IC provided on the circuit board,
A first shield plate extending along one side of the circuit board and facing the one side;
A second shield plate extending along the other surface of the circuit board and facing the other surface;
A document reading apparatus characterized in comprising: a magnetic material sheet which closes a part of a gap between one end of the first shield plate and one end of the second shield plate and does not block the other part. apparatus. The circuit board has a plurality of sides,
2. The document reading apparatus according to claim 1, wherein the magnetic sheet is disposed at a position facing the side closest to the control IC among the plurality of sides. The magnetic sheet is
A first magnetic sheet and a second magnetic sheet laminated on the first magnetic sheet,
3. The document reading apparatus according to claim 1, wherein the second shield plate is sandwiched between the first magnetic material sheet and the second magnetic material sheet at one end. And a housing that houses the control unit;
One end of the magnetic sheet is fixed to the second shield plate,
The document reading apparatus according to any one of claims 1 to 3, further comprising an elastic member contacting the magnetic material sheet extended from the one end of the magnetic material sheet and an inner wall of the housing. apparatus. The first shield plate includes an extending portion extending from the one end of the first shield plate in a direction approaching the second shield plate and spaced apart from the one end of the second shield plate by a predetermined distance.
The gap is present between the extending portion of the first shield plate and the one end of the second shield plate.
The document reading device according to any one of claims 1 to 4, wherein the magnetic material sheet is pressed against the extension portion by an elastic member to close the gap. A harness connected to an outer periphery of the circuit board;
The document reading device according to any one of claims 1 to 5, wherein the magnetic material sheet is disposed at a position not overlapping the harness in a direction from the magnetic material sheet to the control IC. The harness is
A first harness connected to the reading device;
And a second harness connected to the transport unit;
7. The document according to claim 6, wherein the first harness and the second harness are disposed along a side different from the side facing the magnetic material sheet among the sides of the circuit board. Reader. A reading device that reads a sheet conveyed by a conveyance unit, and a control unit that controls the conveyance unit;
Planar circuit board,
A control IC provided on the circuit board,
A first shield plate extending along one side of the circuit board and facing the one side;
A second shield plate extending along the other surface of the circuit board and facing the other surface;
A control unit characterized by comprising a magnetic material sheet which closes a part of a gap between one end of the first shield plate and one end of the second shield plate and does not block the other part. .

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