Electronic device

Abstract

To provide electronic equipment capable of reducing a noise radio wave leaking out without employing a structure which shields an opening part of an enclosure with a conductive member.SOLUTION: An enclosure 4 is formed of an electrically conductive member, and has an opening part 4b. A carrier part 2 is arranged in the enclosure 4, and radiates a noise radio wave. The electrically conductive part 6 is formed of an electrically conductive member, and is arranged on the side of the opening part 4b about the carrier part 2 to overlap at least in part with the opening part 4b in plan view, one end being electrically connected to the enclosure 4 and the other end being an electrically open end.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electronic device.

Background Art

[0002] In an electronic device such as a printing device, noise waves (unnecessary radiation) may be radiated from built-in components and the like (see Patent Document 1). If this noise wave leaks to the outside, it may cause a malfunction in other electronic devices.

[0003] If the housing of the electronic device is made of metal and has a structure without an opening, leakage of noise waves can be suppressed. However, for example, a relatively large opening may be provided in the housing so that maintenance inside the electronic device can be easily performed. In such an electronic device, noise waves may leak from the opening of the housing.

[0004] On the other hand, if the opening is shielded with a conductive member such as metal, the noise waves leaking to the outside can be reduced.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, if the opening is shielded with a conductive member as described above, it will cause an increase in the weight and cost of the electronic device. For this reason, there has been a demand for a technology that can reduce the noise waves leaking to the outside without using a structure in which the opening of the housing is shielded with a conductive member.

[0007] The present invention has been made in view of the above, and an object thereof is to provide an electronic device capable of reducing noise waves leaking to the outside without using a structure in which an opening of a housing is shielded by a conductive member.

Means for Solving the Problems

[0008] To achieve the above object, an electronic device according to the present invention includes a housing formed of a conductive member and having an opening, a radiation source disposed in the housing and radiating noise waves, and a conductive member formed of a conductive member, at least a part of which overlaps the opening in a plan view, and is disposed on the opening side with respect to the radiation source, one end of which is electrically connected to the housing, and the other end of which is electrically an open end. It is characterized by having a conductive part.

Effects of the Invention

[0009] According to the electronic device of the present invention, noise waves leaking to the outside can be reduced without using a structure in which an opening of a housing is shielded by a conductive member.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are denoted by the same or equivalent reference numerals throughout the drawings.

[0012] The following embodiments illustrate apparatuses and the like for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, arrangements, etc. of each component part as those described below. The technical idea of the present invention can be variously modified within the scope of the claims.

[0013] FIG. 1 is a perspective view showing a schematic configuration of a printing apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing a state in which the cover of the printing apparatus shown in FIG. 1 is closed. FIG. 3 is a view showing a schematic configuration of a printing unit and a conveyance unit of the printing apparatus shown in FIG. 1. FIG. 4 is a perspective view of the conveyance unit of the printing apparatus shown in FIG. 1. In the following description, the up, down, left, right, front, and rear directions indicated by the arrows in FIG. 1 are defined as the up, down, left, right, front, and rear directions. In FIG. 2, the cover is shown by a broken line.

[0014] As shown in FIGS. 1 and 2, a printing apparatus (corresponding to an electronic device) 1 according to the present embodiment includes a conveyance unit (corresponding to a radiation source) 2, a printing unit 3, a housing 4, covers (corresponding to doors) 5A and 5B, a conductive unit 6, a connection unit 7, a magnet catch 8, and a suction sheet metal 9.

[0015] The conveyance unit 2 conveys a sheet (not shown) fed from a sheet feeding unit (not shown). The conveyance unit 2 is disposed within the housing 4. The conveyance unit 2 is configured to be movable up and down by a lifting mechanism (not shown). As shown in FIGS. 3 and 4, the conveyance unit 2 includes a conveyance belt 11, a drive roller 12, driven rollers 13 to 15, and side plates 16.

[0016] The conveyance belt 11 adsorbs and holds the sheet and conveys it. The conveyance belt 11 is an annular belt wound around the drive roller 12 and the driven rollers 13 to 15. A large number of belt holes are formed in the conveyance belt 11. The conveyance belt 11 adsorbs and holds the sheet by the adsorption force generated in the belt holes due to the drive of a fan (not shown).

[0017] The drive roller 12 rotates the conveyor belt 11. The drive roller 12 is rotationally driven by a motor (not shown). The driven rollers 13 to 15 support the conveyor belt 11 together with the drive roller 12. The driven rollers 13 to 15 rotate in a driven manner with respect to the conveyor belt 11.

[0018] The side plates 16 rotatably hold the drive roller 12 and the driven rollers 13 to 15. Two side plates 16 are provided in the conveying unit 2. One side plate 16 holds the drive roller 12 and the driven rollers 13 to 15 at the front end, and the other side plate 16 holds the drive roller 12 and the driven rollers 13 to 15 at the rear end. The side plates 16 are formed of a conductive member such as metal.

[0019] The printing unit 3 performs printing on the paper conveyed by the conveying unit 2. The printing unit 3 is disposed above the conveying unit 2 within the housing 4. As shown in FIGS. 1 and 3, the printing unit 3 includes a plurality of inkjet heads 21, a head holder 22, a head holder connection portion 23, and connection pins 24.

[0020] The inkjet head 21 has a plurality of nozzles (not shown) that open on the lower surface facing the conveying unit 2, and ejects ink from the nozzles to form an image on the paper. Inside the inkjet head 21, a plurality of piezoelectric elements for ejecting ink from each nozzle and a head drive IC (both not shown) for driving the piezoelectric elements are disposed.

[0021] The head holder 22 holds the inkjet head 21. The head holder 22 is formed in a hollow substantially rectangular parallelepiped shape. The head holder 22 is formed of a conductive member such as metal. Inside the head holder 22, a drive circuit (not shown) for controlling the drive of each inkjet head 21 is disposed.

[0022] The head holder connection portion 23 connects the head holder 22 to the housing 4.

[0023] The connection pin 24 is a member for positioning the head holder 22 and the conveying unit 2. The connection pins 24 are erected at two positions on the left and right on the front side of the head holder 22. By inserting the connection pins 24 into the connection holes of the liftable conveying unit 2, the conveying unit 2 and the head holder 22 are connected and the conveying unit 2 is positioned. The connection pins 24 are configured to be adjustable in position in the front-rear direction. The connection pins 24 are formed of a conductive member such as metal. In a state where the conveying unit 2 and the head holder 22 are connected by the connection pins 24, the head holder 22 and the side plate 16 of the conveying unit 2 are electrically connected.

[0024] The housing 4 houses the conveying unit 2 and the printing unit 3 therein. The housing 4 is formed in a substantially rectangular parallelepiped shape with a hollow interior. The housing 4 is formed of a conductive member such as metal. The housing 4 is grounded. The housing 4 has an opening 4b that opens a part of the front panel 4a that constitutes the front surface thereof.

[0025] The opening 4b is for enabling the user to access the conveying unit 2 etc. inside the housing 4 when performing maintenance etc. The opening 4b is formed to be large enough for the user to access the conveying unit 2 etc. The opening 4b is formed such that at least a part of the conveying unit 2 enters the opening region of the opening 4b in a plan view (opening surface view). In the present embodiment, the opening 4b is formed such that the entire conveying unit 2 enters the opening region of the opening 4b in a plan view (opening surface view).

[0026] The covers 5A and 5B cover the front surface (front panel 4a) of the housing 4. The cover 5A covers the right side of the front surface of the housing 4, and the cover 5B covers the left side of the front surface of the housing 4. The covers 5A and 5B are formed in a door shape that can be opened and closed. That is, the covers 5A and 5B constitute a door that opens and closes the opening 4b of the housing 4. The covers 5A and 5B are formed of an insulator such as resin.

[0027] The conductive part 6 forms a return path for suppressing the leakage of noise radio waves (unwanted radiation) radiated from the side plate 16 of the conveying part 2 to the outside of the printing apparatus 1 as described later. The conductive part 6 is formed of a conductive member. For example, the conductive part 6 is formed by a conductive tape attached to the cover 5A. The conductive part 6 is arranged on the opening part 4b side with respect to the conveying part 2 so that at least a part thereof overlaps the opening part 4b in a plan view (viewed from the opening surface) when the cover 5A is closed. In the present embodiment, the conductive part 6 is arranged near the opening part 4b outside the housing 4 when the cover 5A is closed.

[0028] The conductive part 6 is formed in an elongated shape in the polarization direction of the noise radio waves radiated from the side plate 16 of the conveying part 2. In the present embodiment, the polarization direction of the noise radio waves radiated from the side plate 16 of the conveying part 2 is the vertical direction. Therefore, the conductive part 6 is formed in an elongated shape in the vertical direction (up and down direction).

[0029] When the cover 5A is closed, one end (lower end) of the conductive part 6 is electrically connected to the housing 4 via the connecting part 7, the magnet catch 8, and the suction sheet metal 9, and the other end (upper end) is electrically an open end. Thereby, the conductive part 6 forms an antenna structure with the conveying part 2 and functions as a return path for noise radio waves. The length of the conductive part 6 in the polarization direction (up and down direction) of the noise radio waves is set to a length corresponding to the wavelength (frequency) of the noise radio waves so that the noise radio waves can be received with high efficiency. The longer the wavelength of the noise radio waves, the longer the length of the conductive part 6 in the polarization direction of the noise radio waves. The length of the conductive part 6 in the polarization direction of the noise radio waves is determined experimentally, for example.

[0030] In this embodiment, the conductive portion 6 is arranged at the position where the noise radio wave is strongest in the left - right direction when the cover 5A is closed. The position of the conductive portion 6 in the left - right direction when the cover 5A is closed is determined experimentally, for example. Also, the distance in the front - rear direction between the conductive portion 6 and the side plate 16 of the transport portion 2 when the cover 5A is closed is equal to or less than a predetermined distance at which the conductive portion 6 can function as a return path for the noise radio wave.

[0031] The connection portion 7 electrically connects the conductive portion 6 and the magnet catch 8. The connection portion 7 is formed of a conductive member. The connection portion 7 is formed by, for example, a conductive tape attached to the cover 5A. The connection portion 7 may be integrally formed with the conductive portion 6.

[0032] The magnet catch 8 is a component that is magnetically adsorbed to the adsorption sheet metal 9 in order to hold the cover 5A in a closed state. Also, the magnet catch 8 electrically connects the connection portion 7 and the adsorption sheet metal 9 when the cover 5A is closed. The magnet catch 8 has a portion formed of a conductive member such as metal, and this portion electrically connects the connection portion 7 and the adsorption sheet metal 9 when the cover 5A is closed. The magnet catch 8 is installed at the lower part inside the cover 5A.

[0033] The adsorption sheet metal 9 is a member to which the magnet catch 8 is adsorbed when the cover 5A is closed. The adsorption sheet metal 9 is formed of a conductive member such as metal. The adsorption sheet metal 9 is installed on the front panel 4a of the housing 4 and is electrically connected to the housing 4.

[0034] Next, the operation of the printing apparatus 1 will be described.

[0035] When printing is performed by the printing apparatus 1, paper is fed from the paper feeding unit to the transport unit 2, and the transport unit 2 transports the paper. Then, the inkjet head 21 of the printing unit 3 ejects ink onto the paper transported by the transport unit 2 to form an image. Here, the printing operation is performed with the covers 5A and 5B closed.

[0036] When the drive circuit described above drives the inkjet head 21 to eject ink during the printing operation, a high-frequency current I with a frequency related to the ejection drive is transmitted to the side plate 16 of the transport unit 2 via the head holder 22 and the connection pin 24. For this reason, the transport unit 2 (its side plate 16) becomes a radiation source of noise radio waves.

[0037] Here, when the covers 5A and 5B are closed, an antenna structure is formed by the transport unit 2 and the conductive unit 6. An image diagram of this antenna structure is shown in FIG. 5. In the antenna structure of FIG. 5, the transport unit 2 (its side plate 16) constitutes the positive electrode, and the conductive unit 6 constitutes the negative electrode. The conductive unit 6 is electrically connected to the grounded housing 4.

[0038] During the printing operation, as shown in FIG. 5, the high-frequency current I described above flows through the transport unit 2. This high-frequency current I flows from the side plate 16 of the transport unit 2 to the conductive unit 6 via the space capacitance. As a result, noise radio waves are radiated from the side plate 16 of the transport unit 2, and the noise radio waves are received by the conductive unit 6. In this way, since the conductive unit 6 serves as a return path for the noise radio waves, the leakage of the noise radio waves to the outside of the printing apparatus 1 is reduced.

[0039] Unlike this embodiment, when there is no conductive unit 6, since there is no return path for the noise radio waves, the leakage of the noise radio waves to the outside of the printing apparatus 1 cannot be suppressed, and there is a risk of causing trouble to peripheral electronic devices.

[0040] As described above, the printing apparatus 1 includes the conductive unit 6. Since this conductive unit 6 serves as a return path for the noise radio waves radiated from the transport unit 2 (its side plate 16), the noise radio waves leaking to the outside of the printing apparatus 1 can be reduced. Also, by providing the conductive unit 6, it is possible to reduce the noise radio waves leaking to the outside of the printing apparatus 1 without making the covers 5A and 5B made of a conductive member such as metal having a structure that shields the opening 4b.

[0041] Therefore, according to the printing apparatus 1, it is possible to reduce the noise waves leaking to the outside without using a structure for shielding the opening 4b of the housing 4 with a conductive member.

[0042] Further, in the printing apparatus 1, the conductive portion 6 is formed in an elongated shape in the polarization direction of the noise waves radiated from the side plate 16 of the conveyance portion 2. Thereby, a return path for the noise waves can be realized with the compact conductive portion 6.

[0043] Further, in the printing apparatus 1, the length of the conductive portion 6 in the polarization direction of the noise waves is set according to the wavelength of the noise waves. Thereby, the conductive portion 6 can receive the noise waves with high efficiency, and the noise waves leaking to the outside can be further reduced.

[0044] Further, in the printing apparatus 1, the conductive portion 6 is installed on the cover 5A, and when the cover 5A is closed, one end is electrically connected to the housing 4. Thereby, a return path for the noise waves by the conductive portion 6 can be realized by using the existing cover 5A.

[0045] Further, in the printing apparatus 1, since the covers 5A and 5B are formed of an insulator such as resin, the conductive portion 6 can be supported at a predetermined position without affecting the return path of the noise waves formed by the conductive portion 6. Further, the weight of the printing apparatus 1 can be reduced.

[0046] In the above-described embodiment, the opening 4b is formed by opening a part of the front surface (front panel 4a) of the housing 4, but it may be formed by opening the entire surface of one surface of the housing 4.

[0047] Further, in the above-described embodiment, the conductive portion 6 is formed in an elongated shape in the polarization direction of the noise waves, but the present invention is not limited to this. For example, the conductive portion 6 may be a wide rectangular planar shape such as a square.

[0048] In the above-described embodiment, the conductive portion 6 is formed by a conductive tape attached to the cover 5A. However, the conductive portion 6 may be formed of a conductive member other than the conductive tape. Further, the conductive portion 6 may be separated from the cover 5A and provided such that one end thereof is electrically connected to the housing 4. Also, the conductive portion 6 may be disposed inside the housing 4 on the side of the opening 4b with respect to the conveying portion 2.

[0049] In the above-described embodiment, one end of the conductive portion 6 is electrically connected to the housing 4 indirectly via a magnet catch 8 or the like, but one end of the conductive portion 6 may be directly electrically connected to the housing 4.

[0050] In the above-described embodiment, the covers 5A and 5B are formed of an insulator such as resin. However, the present invention is applicable even to a configuration in which the cover is formed of a conductive member such as metal but cannot shield the opening 4b.

[0051] In the above-described embodiment, the front surface (front panel 4a) of the housing 4 is covered with two covers 5A and 5B. However, the present invention is not limited to this, and the number of covers may be one or three or more. Further, the conductive portion 6 may be disposed on the side of the opening 4b with respect to the conveying portion 2 in a configuration without a cover.

[0052] In the above-described embodiment, the conductive portion 6 is disposed at a position where the noise radio wave is strongest in the left-right direction when the cover 5A is closed. However, the present invention is not limited to this, and the position of the conductive portion 6 in the left-right direction may be within a predetermined range including the position where the noise radio wave is strongest in the left-right direction. It is desirable that the conductive portion 6 be disposed at a position close to the conveying portion 2 (radiation source) within a range where at least a part of the conductive portion 6 overlaps the opening 4b in plan view (viewed from the opening surface) according to the position of the conveying portion 2 (radiation source).

[0053] In addition, in the above-described embodiment, a printing apparatus has been described as an example. However, the present invention is not limited thereto, and the present invention is applicable to an electronic device in which a noise radio wave radiation source is disposed in a housing having an opening.

[0054] The present invention is not limited to the above-described embodiment as it is, and at the implementation stage, components can be modified and embodied without departing from the gist thereof. Further, various inventions can be formed by appropriately combining a plurality of components disclosed in the above-described embodiment. For example, some components may be deleted from all the components shown in the embodiment.

[0055] [Appendix] This application discloses the following inventions.

[0056] (Appendix 1) A housing formed of a conductive member and having an opening, A radiation source disposed in the housing and radiating noise radio waves, A conductive part formed of a conductive member and disposed on the opening side with respect to the radiation source so that at least a part thereof overlaps the opening in a plan view, one end of which is electrically connected to the housing and the other end of which is electrically an open end An electronic device comprising the above.

[0057] (Appendix 2) The electronic device according to Appendix 1, wherein the conductive part is formed in an elongated shape in the polarization direction of the noise radio wave.

[0058] (Appendix 3) The electronic device according to Appendix 1 or 2, wherein a length of the conductive part in the polarization direction of the noise radio wave is set according to a wavelength of the noise radio wave.

[0059] (Appendix 4) Further comprising a door for opening and closing the opening, The electronic device according to any one of Appendices 1 to 3, wherein the conductive part is installed on the door, and when the door is closed, one end thereof is electrically connected to the housing.

Explanation of Symbols

[0060] 1 Printing device 2 Conveyor section 3 Printing section 4 Housing 4a Front panel 4b Opening 5A, 5B Covers 6 Conductive section 7 Connection section 8 Magnetic catch 9 Suction panel 11 Conveyor belt 12 Driving roller 13 - 15 Driven rollers 16 Side plate 21 Inkjet head 22 Head holder 23 Head holder connection section 24 Connection pin

Claims

1. A housing formed of a conductive member and having an opening, A radiation source disposed within the housing and radiating noise waves, A conductive part formed of a conductive member, disposed on the opening side with respect to the radiation source such that at least a part thereof overlaps the opening in plan view, having one end electrically connected to the housing and the other end electrically open-ended, A door for opening and closing the opening, and The electronic device, wherein the conductive part is installed on the door, and when the door is closed, one end is electrically connected to the housing.

2. The electronic device according to claim 1, wherein the conductive part is formed in an elongated shape in the polarization direction of the noise waves.

3. The electronic device according to claim 1 or 2, wherein the length of the conductive part in the polarization direction of the noise waves is set according to the wavelength of the noise waves.

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