Radio wave absorbing panel mounting structure

Abstract

This structure allows for the attachment of radio wave absorbing panels to a frame member without the use of frame materials, and provides a mounting structure that allows for the attachment of radio wave absorbing panels to the same frame member regardless of wavelength. [Solution] The mounting structure involves attaching a radio wave absorbing panel to a frame member, wherein the radio wave absorbing panel comprises a conductive portion, a through hole formed in the radio wave absorbing panel that penetrates the conductive portion, and a connecting member that is inserted through the through hole and connected to the frame member, and at least a portion of the connecting member is non-conductive.

Description

Technical Field

[0001] The present invention relates to an attachment structure for attaching a radio wave absorption panel to a frame member.

Background Art

[0002] In recent years, various management systems using RFID (Radio Frequency IDentifier) that read and write information of IC tags passing through a specific range in a non-contact manner using radio waves have been developed. In a management system using radio waves, a radio wave absorption panel is used to prevent radio waves from leaking outside the reading range or accidentally reading non-target IC tags.

[0003] Conventionally, as an attachment structure for a radio wave absorption panel, as in Patent Document 1, a box-shaped body with one side open is fitted together in two parts to form a hollow part, and a radio wave absorber is housed in the hollow part, and a panel attachment groove is provided on one side of the box-shaped body. Or, as in Patent Document 2, an attachment structure is disclosed in which a radio wave absorption panel is supported by forming a receiving base in a U-shaped space.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional radio wave absorption panel attachment structure, since the metal frame members are exposed on the radio wave arrival surface at the four end portions of the radio wave absorption panel, the frame members may reflect radio waves and reduce the radio wave absorption performance of the radio wave absorption panel.

[0006] Patent Document 3 proposes a mounting structure that sets the dimensions of the exposed frame material as a fixing method that does not reduce the radio wave absorption performance of the radio wave absorbing panel. However, since a part of the frame material is still exposed on the radio wave arrival surface, it is not possible to suppress the reflection of radio waves, and there are also problems with ease of installation because it is necessary to prepare frame material according to the wavelength.

[0007] The primary objective of this invention is to provide a mounting structure for radio wave absorbing panels that can suppress the degradation of the performance of the radio wave absorbing panels. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention has the following configuration. In other words, the radio wave absorbing panel mounting structure according to the present invention is a mounting structure for attaching a radio wave absorbing panel to a frame member, wherein the radio wave absorbing panel comprises a conductive portion having conductivity, a through hole formed in the radio wave absorbing panel, and a connecting member inserted through the through hole and connected to the frame member, wherein at least a part of the connecting member is non-conductive.

[0009] In the radio wave absorbing panel, a conductive layer and a dielectric layer are laminated in the thickness direction, and through holes may be provided so as to penetrate the conductive layer and the dielectric layer in the thickness direction.

[0010] The radio wave absorbing panel may be a laminate having a dielectric layer and conductive layers on both sides of the dielectric layer. [Effects of the Invention]

[0011] According to the radio wave absorbing panel mounting structure of the present invention, conductive parts can be prevented from conducting electricity with other parts, thus preventing a decrease in radio wave absorption performance. [Brief explanation of the drawing]

[0012] [Figure 1]This is a front view showing an example of an embodiment of the panel mounting structure according to the present invention. [Figure 2] This is a front view showing an example of a conventional panel mounting structure: (a) a radio wave absorbing panel with a frame material, and (b) a radio wave absorbing panel with a margin at the end for connection. [Figure 3] This is a magnified perspective view of a portion of the radio wave absorbing panel during the installation process. [Figure 4] This is a magnified perspective view of a portion of the radio wave absorbing panel after installation is complete. [Figure 5] This is a cross-sectional view of the area surrounding the connecting member as seen from the line AA in Figure 4. [Figure 6] This is a cross-sectional view along line AA according to a second embodiment of the panel mounting structure according to the present invention. [Figure 7] Cross-sectional view AA according to a third embodiment of the panel mounting structure according to the present invention [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be specifically described with reference to the drawings. Figure 1 is a front view of an example of an embodiment of the panel mounting structure according to the present invention, and Figure 2 is a front view of an example of a conventional panel mounting structure, in which (a) is a radio wave absorbing panel equipped with a frame material and (b) is a radio wave absorbing panel equipped with a margin portion for connection at the end.

[0014] Conventional panel mounting structures involved attaching frame members 12 to surround the four corners of the radio wave absorbing panel 1A and connecting the frame members 12, or incorporating the frame member configuration of the frame members 12 and housing the radio wave absorbing panel 1A within the frame members. Alternatively, a structure was adopted in which a margin 17 was provided so as not to place a conductive layer at the location where through-holes would be made, thereby preventing conductivity. However, in configurations using frame members 12, the frame members 12 reflect radio waves, and the margin 17 does not exhibit radio wave absorbing performance. Therefore, when radio waves come from the front side (the front side in Figure 2), reflected or transmitted radio waves leak outside the reading range, leaving the possibility of misreading non-target IC tags.

[0015] On the premise of reducing the radio wave absorption performance, it is possible to fix the radio wave absorption panel to the frame member 2 with the connecting member 3 without using the frame material 12 as shown in FIG. 1. However, at least, since the radio wave absorption performance is reduced in the conductor layer into which the connecting member is inserted, there is a possibility that radio waves are transmitted or reflected in a wider range than in the structure provided with the margin portion 17.

[0016] In the present invention, as shown in FIG. 1, since the radio wave absorption panel 1 has neither the frame material 12 nor the margin portion 17, if it has the same size, it can absorb more radio waves than before.

[0017] FIG. 3 shows a partially enlarged perspective view of a midway stage of attaching the radio wave absorption panel 1 to the frame member 2, FIG. 4 shows a partially enlarged perspective view of a stage where the radio wave absorption panel 1 is completely attached to the frame member 2, and FIG. 5 shows a cross-sectional view of a peripheral portion of the connecting member taken along the line A-A of FIG. 4. The radio wave absorption panel 1 is provided with a through hole 11 so as to penetrate the dielectric layer 15 and the conductor layer 13 in the thickness direction. The frame member 2 is also provided with an attachment portion 21 for attaching the connector 3. The connecting member 3 is inserted through the through hole 11 and the attachment portion 21, and the radio wave absorption panel 1 is attached to the frame member 2.

[0018] The radio wave absorption panel 1 includes a dielectric layer 15, a conductive portion formed by a conductor layer (patch element) 13 arranged in a matrix on the first main surface (front surface), which is the radio wave arrival surface of the dielectric layer 15, a conductor layer (reflective film) 14 formed on the entire second main surface (back surface) of the dielectric layer 15, and a protective layer 16 covering the whole thereof. The radio wave absorption panel 1 absorbs the incident radio waves, converts them into thermal energy, or cancels out the incident radio waves with each other to absorb the radio waves.

[0019] The dielectric layer 15 is formed from a dielectric material that has light transmittance and a high dielectric constant. Depending on the intended use and usage conditions, it is sufficient if the light transmittance is, for example, 50% or more. More preferably, the light transmittance is 70% or more. From the viewpoint of absorbing and attenuating electromagnetic waves, it is desirable that the dielectric material has a high dielectric constant and a large dielectric loss tangent (tanδ). Examples of dielectric materials that satisfy these conditions include PET resin (polyethylene terephthalate), acrylic resin, and PVC (polyvinyl chloride).

[0020] The conductive layer (patch element) 13 is a square electrode and is formed from a metal such as copper, aluminum, or an alloy thereof. The conductive layer 13 is formed, for example, by patterning a conductive film deposited on the first main surface of the dielectric layer 15 by vacuum deposition, sputtering, or the like.

[0021] Furthermore, although the conductive layer 13 is arranged in a matrix, the conductive layer 13 may be arranged across the entire surface of the radio wave absorbing panel, and the structure is not particularly limited as long as the conductive layer 13, including the conductive layer 14, is formed on both the front and back surfaces of the dielectric layer 15.

[0022] The surface of the dielectric layer 15 on which the conductive layer 13 is located functions as the incident surface for electromagnetic waves to the radio wave absorbing panel 1, and no conductive layer, resistive layer, etc. that reflect or shield electromagnetic waves are located on the front side of the conductive layer 13.

[0023] The conductive layer (reflective film) 14 is formed on the back surface of the dielectric layer 15, facing the conductive layer 13. The conductive layer 14 is made of a metal such as copper, aluminum, or an alloy thereof. The conductive layer 14 is formed, for example, from a conductive film deposited on the other main surface of the dielectric layer 15 by vacuum deposition, sputtering, or the like.

[0024] The protective layer 16 is formed from a thin film of an insulating, transparent material that has environmental resistance and contamination resistance, and covers the entire outer surface of the radio wave absorbing panel 1. Examples of such materials include glass and epoxy resin. The thickness of the protective layer 16 on the conductive layer 13 is formed to be thin enough not to affect the absorption characteristics of the dielectric layer 15.

[0025] The radio wave absorbing panel 1 having the above configuration is, for example, mounted on a frame member 2 and arranged in a row on the walls, floor, ceiling, etc. of a room, and absorbs radio waves of a specific frequency emitted from a radio wave source and attenuates reflected waves, thereby reducing interference, congestion, etc.

[0026] The material of the connecting member 3 is made of a non-conductive material. As long as the conductive layer 13 and the conductive layer 14 are not electrically connected by the connecting member 3, it is not particularly limited and may be made of glass, ceramics, PET resin (polyethylene terephthalate), acrylic resin, PVC (polyvinyl chloride), etc.

[0027] In this invention, the connecting member 3 is fixed within the frame member 2, but it may also be fixed by passing through the frame member 2 and sandwiching the radio wave absorbing panel 1 and the frame member 2 with nuts or the like.

[0028] When inserting the radio wave absorbing panel 1, the connecting member 3 contacts the conductive layer 13 and the conductive layer 14 from the inner circumferential surface of the through hole 11. If the connecting member 3 is made of a conductive material like a conventional metal bolt, the conductive layer 13 and the conductive layer 14 will become electrically connected through the connecting member 3. As a result, the incident radio waves will not be absorbed by the radio wave absorbing panel but will be emitted in and out from the connecting member 3. Therefore, the radio wave absorption performance of the conductive layer 13 portion where the through hole is formed will decrease. However, in this invention, since the connecting member 3 is made of a non-conductive material, the conductive layer 13 and the conductive layer 14 will not become electrically connected, and it will be possible to impart radio wave absorption performance to the entire panel installation area without reducing the radio wave absorption performance.

[0029] addition Furthermore, since it does not require a frame to fix the radio wave absorbing panel as in conventional designs, it is possible to prevent misreading of IC tags outside the reading range due to reflection or obstruction of radio wave absorption by the frame. In addition, when a metal frame is used, the conductive layer exposed on the front, back, or sides of the radio wave absorbing panel may come into contact with the frame, causing an electric current to flow and potentially reducing the radio wave absorption performance. However, in this invention, since there is no need to use a frame, the aforementioned performance reduction can be prevented.

[0030] In this embodiment, the connecting member 3 is made of a non-conductive material, but it is sufficient that at least the portion in contact with the conductive layer 13 is non-conductive. As shown in Figures 6 and 7, the connecting member 3 may be made of a conventional metal, and a cover material 31 made of a non-conductive material may be inserted through the insertion hole. However, if the head of the connecting member 3 exposed on the radio wave arrival surface is conductive, it will reflect radio waves, so it is more preferable that the entire material of the connecting member 3 is non-conductive. [Explanation of symbols]

[0031] 1. Radio wave absorbing panel 11 Through hole 12 Frame material 13. Conductive layer (patch element) 14. Conductive layer (reflective film) 15 Dielectric layer 16 Protective layer 2 Frame members 21 Mounting part 3 Connecting members 31 Cover material

Claims

1. This mounting structure involves attaching radio wave absorbing panels to the frame members. The aforementioned radio wave absorbing panel has a conductive portion, The through-holes formed in the radio wave absorbing panel, A connecting member is inserted through the aforementioned through hole and connected to the frame member, At least a portion of the connecting member is non-conductive. Radio wave absorbing panel mounting structure.

2. The aforementioned radio wave absorbing panel has a conductive layer and a dielectric layer stacked in the thickness direction, The radio wave absorbing panel mounting structure according to claim 1, wherein the through-hole is provided so as to penetrate the conductive portion and the dielectric layer in the thickness direction.

3. The radio wave absorbing panel mounting structure according to claim 1, wherein the radio wave absorbing panel is a laminate having a dielectric layer and conductive layers on both sides of the dielectric layer.

Images