Electrical device, and method for arranging conductive member

The present disclosure relates to an electrical device, and a method for arranging a conductive member. A conductive member is arranged to contact the ground portion electrically grounded and the electric wire attached to the ground portion by a first attachment member and a second attachment member. The conductive member is arranged between the first attachment member and the second attachment member.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an electrical device, and a method for arranging a conductive member.

Description of the Related Art

A signal to be transmitted has increased in speed in an electric wire connected inside and outside an electrical device. Therefore, a measure not to release high-frequency radiation noise (hereinafter referred to as an Electromagnetic Interference (EMI) measure) has been required.

A wireless device has increasingly been loaded into the electrical device. Therefore, a measure to make the electrical device normally operate even if exogenous noise is received (hereinafter referred to as an Electromagnetic Susceptibility (EMS) measure) has been required.

To meet both characteristics of the EMI and EMS measures (referred to as Electromagnetic Compatibility (EMC)), a shielding measure to cover an electric wire with a metal shield has been taken.

It is desirable for EMC to reliably ground a shield portion of an electric wire, which has been shielded, to a Ground (GND) sheet metal in the electrical device by pressing and fixing the electric wire on the GND sheet metal in the electrical device. Even if a shielding member has blocked radiated noise or exogenous noise, when a current caused by an electric field or a magnetic field received in the shield portion stays without flowing to a GND, the current generates an electric field or a magnetic field.

In an image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2012-54458, engagement portions in a pressing retainer made of a metal wire are fitted into respective engagement holes provided on both sides of a supporting member made of a metal plate serving as a member constituting the apparatus to engage therewith, to fix a flexible flat cable to the supporting member.

Examples of an electric wire connected inside or outside the electrical device include an electric wire having a rounded shape in addition to an electric wire having a flat shape like a flexible flat cable.

When the electric wire connected inside or outside the electrical device is attached to a ground portion such as a GND sheet metal using two attachment members, a distance between the ground portion and the electric wire increases depending on a shape of the electric wire that has been shielded. When the electric wire too separates from the ground portion electrically grounded, the electromagnetic wave released from the electric wire cannot be suppressed.

SUMMARY OF THE INVENTION

The present invention is directed to providing an apparatus in which a conductive member is arranged to contact an electric wire attached to a ground portion by a first attachment member and a second attachment member, and the ground portion, and is arranged between the first attachment member and the second attachment member, and a method therefor.

According to an aspect of the present invention, an electrical device includes a ground portion electrically grounded, and a conductive member arranged to contact an electric wire attached to the ground portion by a first attachment member and a second attachment member, and the ground portion, and arranged between the first attachment member and the second attachment member.

DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments of the present invention will be specifically described below with reference to the accompanying drawings. The following exemplary embodiments are not intended to limit the invention according to the scope of claims, and all of combinations of features described in the exemplary embodiments are not necessarily essential for a solution to the invention.

In a first exemplary embodiment, a conductive member is arranged to contact a ground portion electrically grounded and an electric wire attached to the ground portion by a first attachment member and a second attachment member. The conductive member is arranged between the first attachment member and the second attachment member. When the electric wire is thus grounded, an electromagnetic wave released from the electric wire is suppressed.

The present invention will be specifically described below.

A hardware configuration of a multi functional peripheral (MFP)10serving as an example of an electrical device according to a first exemplary embodiment of the present invention will be described with reference to a block diagram ofFIG. 1.

The MFP10has a copy function for reading a document to generate image data and printing an image on a sheet based on the generated image data. The MFP10has a personal computer (PC) print function for receiving a print job from an external device such as a PC or an external server and printing characters and an image on a sheet based on data representing a received print instruction. The MFP10has a facsimile (FAX) print function for receiving a FAX job from a FAX and printing characters and an image on a sheet based on data representing the received FAX job. Printing using the print function may be color printing or monochrome printing.

The PC generates image data with application software and transmits the generated image data to the MFP10, for example. The PC generates Page Description Language (PDL) data using a printer driver, for example. A main controller unit200in the MFP10rasterizes the PDL data sent from the PC via a network102, to generate bit map data.

The main controller unit200is connected to the external device such as the PC or the external server via the network102, and performs processing such as the receiving of the print job from the external device. The network102may be a Local Area Network (LAN) or a Wide Area Network (WAN) such as the Internet.

The main controller unit200is connected to the FAX via a FAX line103, to perform processing such as the receiving of the FAX job from the FAX.

The main controller unit200in the MFP100is connected to a scanner unit300serving as an image input device and a printer unit400serving as an image output device, and controls input and output of image information.

The scanner unit300includes an automatic document feeding unit that conveys a document loaded on a document tray and an image reading unit that reads an image on the document using an optical sensor such as a charge-coupled device (CCD) sensor. The image reading unit transfers image data generated by reading the image on the document to the main controller unit200.

The scanner unit300includes a scanner driving portion including a driving portion for moving a reading head that reads a document and a driving portion for conveying the document to a reading position, and a scanner control portion that controls an operation of the scanner driving portion. The scanner control portion receives, through communication with the main controller unit200, setting information set by a user when scanner processing is performed, to control an operation of the scanner driving portion based on the setting information.

The printer unit400prints an image on a sheet based on the image data input from the scanner unit300, the PC, the external server, or the FAX.

The printer unit400forms an image on a sheet according to an electrophotographic method, for example. The printer unit400includes a printer driving portion including a motor that rotates a photosensitive drum, a mechanism portion for pressurizing a fixing unit, and a heater, and a printer control portion that controls an operation of the printer driving portion. The printer control portion receives, through communication with the main controller unit200, setting information set by the user when print processing is performed, to control an operation of the printer driving portion based on the setting information.

The printer unit400may print an image on a sheet using an inkjet method, for example, or use other methods (e.g., a thermal transfer method) if the image can be printed on the sheet.

The main controller unit200performs integrated operation control of the MFP10including the scanner unit300and the printer unit400in response to an instruction from the user that has been input via an operation unit500corresponding to one example of a user interface unit.

The main controller unit200performs operation control of a power supply unit100, to control a power mode of the MFP10.

The MFP10includes a human presence sensor unit600for detecting a person who approaches the MFP10. When the human presence sensor unit600detects the person who comes close to the front of the MFP10, the MFP10returns from a power saving mode in which power consumption is low, to a power state where any one of a print function, a scanner function, a copy function, and a FAX function can be used.

The human presence sensor unit600is an infrared array sensor, and receives infrared rays radiated from the body temperature of a person using light receiving portions arranged in a line shape or a matrix shape and detects a position of the person and a distance between the person and the MFP100using an infrared light receiving intensity distribution.

The operation unit500performs an operation of the human presence sensor unit600and power supply control. The infrared array sensor and the operation unit500are connected to each other via an Inter-Integrated Circuit (I2C) bus.

The human presence sensor unit600may be a ultrasonic sensor. The ultrasonic sensor outputs a pulse wave having a frequency of 40 KHz in an inaudible region while receiving a reflected wave of the pulse wave reflected by an object. The ultrasonic sensor measures a distance between the MFP10and the object based on a period of time elapsed until it receives the reflected wave since it outputs the pulse wave.

Furthermore, the human presence sensor unit600may be an infrared reflection sensor, which receives radiated infrared rays, if it can detect the presence or absence of a person and a change in distance. A capacitance sensor, which measures a distance between a sensor and a target object based on a capacitance between the sensor and the target object, may be used.

The operation unit500, the human presence sensor unit600, a Near Field Communication (NFC) unit700, a wireless communication unit800, and a card reader unit900in the MFP10illustrated inFIG. 2will be described below with reference to an external view in the vicinity of the operation unit500.

The MFP10includes the NFC unit700for performing NFC communication with the external device.

The NFC unit700has a reader function for reading information recorded on an authentication card held over the NFC unit700and a writer function for writing Internet Protocol (IP) address information and data in the MFP10into a mobile device such as a smartphone held over the NFC unit700, for example. The operation unit500performs operation control of the NFC unit700.

While the NFC unit700in the MFP10is incorporated into the operation unit500in the MFP10, the NFC unit700is arranged in a location near the operation unit500that is easily operated by the user.

The wireless communication unit800is a module for performing communication between the MFP10and the external device via a wireless network104(e.g., a wireless local area network (LAN) in an Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard and Bluetooth (registered trademark) in an IEEE 802.15.1 standard). The wireless communication unit800is loaded with an antenna portion and a control integrated circuit (IC) that controls communication, and is controlled by being connected to the main controller unit200.

The wireless communication unit800is arranged near the operation unit500close to a position where the user stands so that it can perform near field communication with the external device owned by the user.

The operation unit500includes a liquid crystal display (LCD) panel, a touch panel, a key portion, which detects a key operation by the user, including a numeric keypad and a start key, and a buzzer.

Image data created and received from a central processing unit (CPU) in the main controller unit200is rendered on the LCD panel. When the user touches and operates the touch panel, a touch panel controller analyzes coordinate data at a touched site and notifies a microcomputer in the operation unit500of the analyzed coordinate data, and the microcomputer notifies the CPU in the main controller unit200of the analyzed coordinate data. The microcomputer in the operation unit500also performs operation control of the human presence sensor unit600and the NFC unit700in addition to input control of the touch panel and the key portion.

The card reader unit900is a device for reading an electronic card used for authentication login using an identification (ID) card. The card reader unit900transmits read ID information to the main controller unit200. The card reader unit900is used when an ID card, which cannot cope with NFC communication, is used.

Around the operation unit500, the card reader unit900and the wireless communication unit800are arranged so that they are easily operated by the user, and the human presence sensor unit600is arranged so that the user in the vicinity of the operation unit can be detected. The NFC unit700is incorporated into the operation unit500.

A configuration of an internal arrangement around the operation unit500will be described below with reference to an arrangement diagram ofFIG. 3. The arrangement diagram ofFIG. 3illustrates an internal substrate and a cable arrangement.

A human presence sensor substrate610, a wireless communication substrate810, a card reader910, and an operation unit earth sheet metal15, for example, are loaded on a frame earth sheet metal11(hereinafter referred to as an earth sheet metal11) in the main body of the MFP10(i.e., a casing of the electrical device). The earth sheet metal11and the operation unit earth sheet metal15are one example of a ground portion electrically grounded, or one example of a plate-shaped metal member.

The operation unit earth sheet metal15is loaded with an operation unit microcomputer substrate510, a key substrate511, an NFC substrate710, an LCD unit, and a touch panel.

An antenna unit722and a control chip721are mounted on the NFC substrate710. The NFC substrate710is connected to the operation unit microcomputer substrate510via an NFC bundle line730.

The bundle line means a line obtained by bundling electric wires (electric wires in a bundled state are hereinafter referred to as a “bundle line”).

The NFC bundle line730has an entire length of approximately 100 mm, for example, because the operation unit microcomputer substrate510and the NFC substrate710are arranged close to each other, and is attached to the operation unit earth sheet metal15inside the operation unit500. A Serial Peripheral Interface (SPI) bus and a control signal are transmitted to the NFC bundle line730.

A push switch522and a light emitting diode (LED)523are mounted on the key substrate511. The key substrate511is connected to the operation unit microcomputer substrate510via a key bundle line534.

The key bundle line534has an entire length of approximately 200 mm, for example, because the operation unit microcomputer substrate510and the key substrate511are arranged close to each other, and is attached to the operation unit earth sheet metal15inside the operation unit500. A control signal representing a state of the push switch522is transmitted to the key bundle line534.

An antenna unit822and a control chip821are mounted on the wireless communication substrate810. The wireless communication substrate810is connected to the main controller unit200via a wireless communication bundle line830.

The main controller unit200is installed on the side of a back surface of the MFP10. The main controller unit200is arranged on the opposite side to the operation unit500. Therefore, the entire length of the wireless communication bundle line830exceeds 1000 mm, for example.

The wireless communication bundle line830is a Universal Serial Bus (USB) bundle line, and a shield in the bundle line and a substrate connector shield are connected to each other so that a signal quality is ensured and a measure against noise is taken.

The card reader910is a card reader unit. The card reader910is connected to the main controller unit200by a USB signal.

The card reader910is connected to the main controller unit200on the side of the back surface of the MFP10. Thus, a card reader bundle line930has its entire length exceeding 1000 mm, for example. However, a shield in the bundle line and a substrate connector shield are connected to each other so that a signal quality is ensured and a measure against noise is taken.

An operation unit microcomputer521is mounted on the operation unit microcomputer substrate510. The operation unit microcomputer substrate510controls the NFC substrate710, the key substrate511, and the human presence sensor substrate610.

In the operation unit microcomputer substrate510, detection data from the touch panel connected to the tip of a touch panel bundle line533is also processed. The operation unit microcomputer substrate510is also connected to the main controller unit200, an operation unit bundle line531, and an operation unit power supply bundle line532.

The operation unit power supply bundle line532supplies power to the operation unit microcomputer substrate510from the main controller unit200.

A serial communication signal between the main controller unit200and the operation unit microcomputer521and serial data of an image to be rendered on the LCD panel connected to the main controller unit200via the operation unit power supply bundle line532are transmitted to the operation unit bundle line531.

The operation unit power supply bundle line532and the operation unit bundle line531have their entire lengths exceeding 1000 mm, for example, because they are connected to the main controller unit200on the side of the back surface of the MFP10. However, a shield in the bundle line and a substrate connector shield are connected to each other so that a signal quality is ensured and a measure against noise is taken.

An infrared array sensor621is mounted on the human presence sensor substrate610. The human presence sensor substrate610is connected to the operation unit microcomputer substrate510via a human presence sensor bundle line630.

The human presence sensor substrate610is directed toward the operation unit500from a location slightly spaced apart from the operation unit500so that it can detect the user who approaches the operation unit500. This is because when the human presence sensor unit600is arranged, the user who approaches from just near the operation unit500cannot be detected due to an effect of a viewing angle of the human presence sensor unit600.

When the operation unit500is assembled, the operation unit bundle line531, the operation unit power supply bundle line532, and the human presence sensor bundle line630need to be inserted afterward into the operation unit microcomputer substrate510. Thus, the bundle line previously needs to have an extra length to ensure workability. Accordingly, the entire length of the human presence sensor bundle line630is as large as approximately 600 mm, for example.

An I2C serial signal and a power supply are transmitted to the human presence sensor bundle line630. The I2C serial signal is easily affected by EMI and EMS because it is a high-impedance signal.

In the first exemplary embodiment, the wireless communication substrate810, which generates an electric wave, exists near the human presence sensor substrate610and the human presence sensor bundle line630. Therefore, an electrical device that is affected by EMS is assumed.

In the electrical device according to the first exemplary embodiment, a portion, corresponding to the extra length for inserting the human presence sensor bundle line630afterward into the operation unit microcomputer substrate510, of the human presence sensor bundle line630is spaced apart from the earth sheet metal11.

Furthermore, in the electrical device according to the first exemplary embodiment, a location where a portion other than the portion corresponding to the extra length of the human presence sensor bundle line630can be attached to the earth sheet metal11is arranged near the card reader910. More specifically, in the electrical device according to the first exemplary embodiment, the location where the portion other than the portion corresponding to the extra length of the human presence sensor bundle line630can be attached to the earth sheet metal11is limited to a bent portion at a corner of the earth sheet metal11.

In the first exemplary embodiment, even an electrical device that cannot provide much grounding space for a bundle line to be connected thereto can provide stable performance for EMI and EMS standards.

More specifically, in the first exemplary embodiment, the conductive member is arranged to contact the ground portion electrically grounded and the electric wire attached to the ground portion by the first attachment member and the second attachment member. The conductive member is arranged between the first attachment member and the second attachment member. When the electric wire is thus grounded, the electromagnetic wave released from the electric wire is suppressed. The present invention will be specifically described below.

A method for shielding the human presence sensor bundle line630according to a first exemplary embodiment will be first described with reference to schematic views ofFIGS. 4A to 4C.

FIG. 4Aillustrates an initial state, and uses a pressure contact connector. In a terminal arrangement, the first pin corresponds to a power supply Vcc, the second pin corresponds to a Serial Clock (SCL) (I2C clock), the third pin corresponds to Serial Data (SDA) (I2C data), and the fourth pin corresponds to a GND.

FIG. 4Billustrates a state where a conductive fabric tape51serving as an example of a shielding member for shielding an electromagnetic wave is wound around the human presence sensor bundle line630. A way of winding the conductive fabric tape51around the human presence sensor bundle line630may be a spiral way of winding illustrated inFIG. 4Bor may be a way of winding like a rolled sushi in dried laver seaweed. When the human presence sensor bundle line630is inserted into a substrate connector, the conductive fabric tape51is spaced approximately 30 mm, for example, apart from a connector portion so that the conductive fabric tape51and an eclectic component in a substrate are not short-circuited.

FIG. 4Cillustrates a state where the conductive fabric tape51is wound around the human presence sensor bundle line630, and a reuse band52is further wound therearound. The reuse band52is an example of an attachment member for attaching an electric wire to a ground portion electrically grounded, and need not have conductivity. While an example in which an approximate reuse band is selected as the reuse band52depending on the diameter of a bundle line to be used, the diameter of an attachment hole, and the plate thickness of an attachment sheet metal has been described, the reuse band52may be of a push mount type that is not reusable.

In the first exemplary embodiment, two reuse bands52are used, and a distance X between the reuse bands is determined depending on locations to which the respective reuse bands52are attached and the width of a conductor, described below.

The conductive fabric tape51may be not a fabric tape but a conductive spiral tube or a braided shield.

A method for grounding the human presence sensor bundle line630around which the conductive fabric tape51is wound (a bundle line, which has been shielded, is also hereinafter merely referred to as a “bundle line”), according to the first exemplary embodiment will be described below with reference to schematic views ofFIGS. 5A to 5B.

In the first exemplary embodiment, conductive gaskets53are sandwiched between two holes12for attaching the respective reuse bands52for attaching the bundle line to ground the bundle line. The conductive gasket53is an elastic member, having flexibility and having a cushioning characteristic, composed of a material such as rubber. The conductive gasket53is a conductor, and is an example of a conductive member.

A state where the bundle line has not yet been attached to the earth sheet metal11will be first described with reference to the schematic view ofFIG. 5A.

In an example illustrated inFIG. 5A, the two holes12for attaching the respective reuse bands52are opened in the earth sheet metal11. The two conductive gaskets53serving as an example of a conductive member are stuck between the two attachment holes12. The number of conductive gaskets53to be stuck may be one, or may be two or more. The number of conductive gaskets53may be changed depending on the area in which the bundle line is to be grounded.

A state where the bundle line has been attached to the earth sheet metal11will be then described with reference to the schematic view ofFIG. 5B.

In an example illustrated inFIG. 5B, the two reuse bands52are inserted into the respective attachment holes12, to attach the bundle line with the conductive gaskets53sandwiched therebetween. At this time, the conductive gaskets53are crushed under pressure from the bundle line attached by the two reuse bands52, and are sandwiched between the bundle line and the earth sheet metal11. Thus, the bundle line and the conductive gasket53contact each other while the conductive gasket53and the earth sheet metal11contact each other. A member having conductivity other than the conductive gasket53may be used as a modification if it is a conductor that has a cushioning characteristic characterized by being thus crushed. For example, the conductive gasket53may be replaced with a urethane foam having conductivity. The urethane foam is a sponge member having flexibility and having a cushioning characteristic.

Respective positions of the bundle line and the conductive gasket53according to the first exemplary embodiment will be described below with reference to schematic views ofFIGS. 6A to 6D. In each ofFIGS. 6A to 6D, an A-A cross section is a cross section viewed from above, and a B-B cross section is a cross section viewed from the side.

FIGS. 6A and 6Crespectively illustrate examples in which the number of conductive gaskets53to be attached to the earth sheet metal11is one.

FIG. 6Aillustrates an example in which the conductive gasket53is stuck to be perpendicular to the bundle line.

On the other hand,FIG. 6Cillustrates an example in which the conductive gasket53is stuck to be parallel to the bundle line.

The area in which the bundle line and the conductive gasket53contact each other is larger when they are parallel to each other inFIG. 6Cthan when they are perpendicular to each other inFIG. 6A. However, in a case illustrated inFIG. 6C, the conductive gasket53is not wide enough for the bundle line in an A-A cross section so that the bundle line may come off the conductive gasket53.

Thus, the bundle line and the conductive gasket53can reliably contact each other when perpendicular to each other inFIG. 6A.

On the other hand,FIGS. 6B and 6Drespectively illustrate examples in which the number of conductive gaskets53to be attached to the earth sheet metal11is two.

FIG. 6Billustrates an example in which the conductive gaskets53are stuck to be perpendicular to the bundle line.

On the other hand,FIG. 6Dillustrates an example in which the conductive gaskets53are stuck to be parallel to the bundle line.

The area in which the bundle line and the conductive gasket53contact each other is larger when they are parallel to each other inFIG. 6Dthan when they are perpendicular to each other inFIG. 6B. However, in a case illustrated inFIG. 6D, there is not enough space to sandwich the conductive gasket53between the bundle line and the earth sheet metal11. If an adhesive tape degrades with age, the conductive gasket53may come off the bundle line. In a case illustrated inFIG. 6D, a force to press the conductive gasket53against the bundle line is not exerted. Therefore, a contact characteristic between the bundle line and the conductive gasket53is not stabilized.

Thus, the bundle line and the conductive gasket53can reliably contact each other when perpendicular to each other inFIG. 6B.

The area in which the bundle line and the conductive gasket53contact each other becomes lager inFIG. 6Bin which the two conductive gaskets53are used than inFIG. 6Ain which the one conductive gasket53is used. While the conductive gasket53is perpendicular to the bundle line in both the example illustrated inFIG. 6Aand the example illustrated inFIG. 6B, an effect of a measure against noise is higher in the example illustrated inFIG. 6Bthan in the example illustrated inFIG. 6A. A plurality of conductive gaskets53may be attached to the earth sheet metal11. How many conductive gaskets53are used may be selected depending on a space for a grounding location, costs, and a noise effect.

A positional relationship among members required to ground a bundle line according to the first exemplary embodiment will be described below with respect to schematic views ofFIGS. 7A and 7B.FIG. 7Ais a side view, andFIG. 7Bis an upper perspective view.

As illustrated inFIG. 7A, the thickness h of the conductive gasket53is selected to be not less than the thickness y of a part of the reuse band52, and is selected so that the conductive gasket53is crushed by approximately half (0.4 to 0.6). At this time, a relationship between the thickness y of the part of the reuse band52and the thickness of the conductive gasket53is expressed by the following expression (1):
h≥y/α (α=0.4˜0.6)  (1)

In the first exemplary embodiment, when y=6 mm is selected, h=10 mm is selected as an appropriate example.

If the width w of the conductive gasket53is smaller than the thickness h thereof, the conductive gasket53falls when crushed so that the conductive gasket53may be separated from the earth sheet metal11. Therefore, the width w of the conductive gasket53is selected to be larger than the thickness h thereof. At this time, a relationship between the width w and the thickness h of the conductive gasket53is expressed by the following expression (2):
w≥h(2)

In the first exemplary embodiment, w=10 mm serving as an easily available general-purpose size is selected as an appropriate example.

The length L of the conductive gasket53is selected to be sufficiently larger than the diameter D of the bundle line and to be not less than two times the width w thereof. At this time, a relationship between the width w and the length L of the conductive gasket53is expressed by the following expression (3):
L≥2·w(3)

In the first exemplary embodiment, L=30 mm is selected as an appropriate example.

10 mm or more is desirably ensured as a distance b from the hole12for attaching the reuse band52to the earth sheet metal11to the conductive gasket53so that the reuse band52can be detachably attached. On the other hand, when the distance b from the hole12to the conductive gasket53increases, a force to crush and press the conductive gasket53becomes weak. Therefore, the distance b is desirably limited to 20 mm. At this time, the distance b from the hole12to the conductive gasket53is expressed by the following expression (4):
20 mm≥b≥10 mm  (4)

In the first exemplary embodiment, b=13 mm is selected as an appropriate example.

A distance c between the conductive gasket53and the conductive gasket53is determined in consideration of a crushing amount α of the conductive gasket53. A simply crushed portion becomes a circular arc of a semicircle, and an extrusion amount of the crushed portion is the radius of the semicircle. It is assumed that the sum of the extrusion amount of the crushed portion of the conductive gasket53and an extrusion amount of a crushed portion of an adjacent conductive gasket53becomes the diameter of a circle. At this time, a relationship among the distance c between the conductive gaskets53, the thickness h of the conductive gasket53, and the crushing amount α of the conductive gasket53is expressed by the following expression (5):
c≥α·h(5)

In the first exemplary embodiment, c=6 mm is selected as an appropriate example.

A distance a (a predetermined distance) between the holes12for attaching the two respective reuse bands52is set to the sum of the above-described calculation results. More specifically, when one gasket53is used, the distance a is expressed by the following expression (6):
a=2b+w(6)

When two gaskets53are used, the distance a is expressed by the following expression (7):
a=2b+2w+c(7)

When n gaskets53are used, the distance a is expressed by the following expression (8):
a=2b+n·w+(n−1)·c(8)

A distance x between the two reuse bands52is the distance a between the holes12for attaching the two reuse bands52. More specifically, a relationship between the distance x between the two reuse bands52and the distance a between the holes12for attaching the two reuse bands52is expressed by the following expression (9):
x=a(9)

As described above, in the first exemplary embodiment to which the present invention is applied, the conductive member is arranged to contact the ground portion electrically grounded and the electric wire attached to the ground portion by the first attachment member and the second attachment member. The conductive member is arranged between the first attachment member and the second attachment member. When the electric wire is thus grounded, an electromagnetic wave released from the electric wire can be suppressed.

Particularly when the conductive gasket53serving as a conductor and also an elastic member having a cushioning characteristic is used as an example of the conductive member, the electromagnetic wave released from the electric wire can be suppressed regardless of a constraint of a grounding space and a constraint of a shape of the electric ware.

In the above described first exemplary embodiment, an example in which a signal to be transmitted to a bundle line is a high-impedance signal, like the I2C signal to be transmitted to the human presence sensor bundle line630has been described. On the other hand, the first exemplary embodiment to which the present invention is applied is also effective for grounding a shield in an impedance control signal bundle line to fix an impedance value depending on a distance from an earth ground. The first exemplary embodiment to which the present invention is applied is also effective for grounding a shield in a signal bundle line having a low amplitude and easily affected by EMS. The first exemplary embodiment to which the present invention is applied is also effective for grounding a shield in a signal bundle line having a large signal amplitude, early switched, and easily radiating EMI.

While a method for grounding the human presence sensor bundle line630has been described in the above described first exemplary embodiment, the present invention is also similarly applicable to a bundle line other than the human presence sensor bundle line630.

A method for grounding a bundle line according to a second exemplary embodiment will be described with respect to schematic views ofFIGS. 8A and 8B.

FIG. 8Ais a cross-sectional view illustrating a scanner unit300and a printer unit400in an MFP10.

A groove portion803is a groove having a recess for passing a bundle line.

A bundle line801is a bundle line installed in the groove portion803. While the scanner unit300in the MFP10is loaded on the printer unit400, the bundle line801wired to an upper surface of the printer unit400from a main controller unit200is installed in the groove portion803not to be crushed by the scanner unit300.

EMI generated by the main controller unit200may be radiated from the bundle line801so that shielding and grounding are required as a measure against noise.

A bundle line802is a bundle line for transmitting image data read by the scanner unit300to the main controller unit200.

The bundle line802is a differential serial dataline, and includes a shield for controlling an impedance. That is, the bundle line802is not easily bent because it includes a shield.

If the bundle line802is wired along a corner of the earth sheet metal11, as illustrated in a schematic view ofFIG. 8B, the bundle line802swells because it is not easily bent. Thus, if the bundle line802is wired along the corner of the earth sheet metal11, the bundle line802separates from the earth sheet metal11.

When a bundle line separates from the earth sheet metal11, the bundle line is affected by EMI and EMS even if it is shielded. Thus, the bundle line needs to be brought close to the earth sheet metal11and grounded.

A conductive member (e.g., a conductive gasket53) for supporting the bundle line801or the bundle line802may be arranged in a space sandwiched between a ground portion and a shielding member in the bundle line, to attach the bundle line to the ground portion using an attachment member for attaching the bundle line to the ground portion.

When the bundle line801is attached to the groove portion803and when the bundle line802is attached to a folded portion at the corner of the earth sheet metal11, if an electric wire is grounded, like in the second exemplary embodiment, in a location where an attachment member is not easily added around the bundle line, an electromagnetic wave released from the electric wire can be suppressed.

Particularly when a conductive gasket53serving as a conductor and also an elastic member having a cushioning characteristic is used as an example of the conductive member, the electromagnetic wave released from the electric wire can be suppressed regardless of a constraint of a grounding space and a constraint of a shape of the electric ware.

Other Exemplary Embodiments

The present invention is not limited to the above described exemplary embodiments. Various modifications (including an organic combination of the exemplary embodiments) can be made based on the scope of the present invention, and are not intended to be excluded from the scope of the present invention.

While the exemplary embodiments to which the present invention is applied have been described using the MFP10including the scanner unit300and the printer unit400, the present invention is not limited to this. The exemplary embodiments to which the present invention is applied can also be similarly described in an image processing apparatus such as a scanner not including the printer unit400, an image forming apparatus such as a printer not including the scanner300, and an electrical device such as a PC including neither the scanner unit300nor the printer unit400.

This application claims the benefit of Japanese Patent Application No. 2015-150513, filed Jul. 30, 2015, which is hereby incorporated by reference herein in its entirety.