JPH11191687A - Window structure with electromagnetic shielding property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a window structure which is capable of ensuring electromagnetic shielding property to a window's peripheral part by a method, wherein a simple structure is additionally provided to eliminate the reflection of electromagnetic waves from metals in the pocket of a metal sash frame and to lessen a resonant coefficient to make a window glass's peripheral edge function as a freely open end, even in a case where the linear antenna element is put in the pocket of the metal sash frame in a tie-in between a window glass, where the linear antenna element is arranged so as to enhance it in electromagnetic shielding property and the metal sash frame, and as a result, the linear antenna element is restrained from deteriorating in shielding property. SOLUTION: A linear antenna element 5 of a prescribed length for resonating with radio waves which is to be blocked is made to serve as an electromagnetic shielding element, a window glass 1 where the elements 5 are arranged regularly, taking their electromagnetic field reflection equivalent area (scattering aperture area) or electromagnetic field reflection equivalent volume (scattering aperture volume) into consideration is fitted in a metal sash frame 2. At this point, a radio wave absorbent 8 is filled between the window glass 1 and the metal sash frame 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a window of a vehicle such as a building, a car or a train, and a window of a furniture such as a partition or a box, which has an electromagnetic shielding property.

[0002]

2. Description of the Related Art As a window glass 1 capable of electromagnetically shielding by selecting only a radio wave band of a required frequency without impairing daylighting and visibility, as shown in FIG. A linear antenna element 5 having a length corresponding to a frequency (wavelength) is regularly arranged on the window glass 1 in consideration of an electromagnetic field reflection equivalent area or volume, and a radio wave is attenuated by the linear antenna element 5. What has been proposed. 2 is a metal sash frame.

[0003] Explaining this principle first, when a radio wave is incident on this surface as shown in FIG. 14 when a conductor piece is in the air, one part is reflected, one part is absorbed, and the other is transmitted. The amount of attenuation of the radio wave by the conductor piece differs depending on the shape and size of the conductor piece. If this conductor piece is a linear antenna element (dipole) having an open end, the radio wave is reflected and a part is absorbed.

As shown in FIG. 15, a linear antenna element 3 having a half wavelength (λ / 2) placed in parallel with a plane electromagnetic field is not limited to the area of the metal part of the antenna element, but receives electromagnetic wave energy. , And absorbs the electromagnetic field near the metal surface. Although the spread is not uniform, the calculated value of the equivalent cross-sectional area Ae is expressed by the following equation 1.

[0005]

[Formula 1] Ae ≒ 0.13λ ² (area of λ / 2 × λ / 4)

[0006] Most of the received electromagnetic wave energy is reflected, and about 1/4 is received as electric power. This is the effective aperture.

As shown in FIG. 16, such a half wavelength (λ
/ 2) When the input resistance of the linear antenna is short-circuited, if the antenna element has no ideal loss, all the power is reflected (scattered) in space, and its equivalent area is four times the effective aperture. By arranging the elements of such a linear antenna element 3 on the window glass 1 as shown in FIG. 17 according to the reflection equivalent area 4 × Ae, it is possible to obtain the same radio wave reflection as if a metal film was attached. Show the effect. The antenna element generally has frequency dependency, and its characteristics and the receiving end resistance = 0 are the basic operations of the element by the linear antenna element 3,
If the linear antenna has a loss, a part of the radio wave is absorbed by the antenna loss resistor as power.

In addition, since the linear antenna elements 3 are scattered, the lighting and visibility of the window glass 1 are not impaired. Note that the thickness of the conductive wire forming the linear antenna element 3 is selected to be thin and small in loss so as not to obstruct the view.

However, arranging the linear antenna elements 3 in a horizontal line as shown in FIG. 17 resonates only with the horizontal polarization, and the polarization plane of the actual radio wave is not in such a horizontal line.
It cannot handle radio waves with various polarization planes. Therefore, the linear antenna element 3 is formed by a thin line as shown in FIGS.
b was provided as a linear antenna element 5 having an open end, which is a Y-shaped element provided with three pieces. When the wavelength of the electromagnetic wave to be shielded is λ and the equivalent relative permittivity when the linear antenna elements are arranged on the glass surface is εq, the length of one side of the linear antenna element 5 is approximately λ / (4√εq ) Is a horizontal Y-shaped element.

If the shape is extended in three directions as a Y-shape as described above, the problem can be solved because the radio wave resonates with any element regardless of the inclination of the plane of polarization. Further, when arranging the linear antenna 5, the end of each side 5b is arranged close to the center 5a of the adjacent linear antenna 5, so that the whole is close to a fish scale pattern.

As the window glass 1 on which the linear antenna element 5 is provided, a float plate glass or a heat ray absorbing glass is preferable, and the linear antenna element 5 has a linear antenna element 5 on the glass surface or between the glass plates. As a method of regularly arranging in consideration of the reflection equivalent area,
A method of printing a metal paste of silver, copper, gold, or the like on a silk screen or attaching a conductive film film, or a method of mounting an element using a metal wire by bonding or the like can be considered.

[0012]

By the way, in the case of a window glass in which the linear antenna element 5 is arranged to perform electromagnetic shielding,
This linear antenna element 5 can be shielded without any electrical contact (even if there is a gap), but in relation to the metal sash frame 2, a wire that enters the metal sash frame 2 (pocket). Although the electromagnetic wave does not directly enter the antenna element 5 ',
Electromagnetic waves arriving at the adjacent linear antenna element 5 are scattered and reach the linear antenna element 5 ′, and are further reflected on the inner wall surface of the metal sash frame 2, resonate with the cavity, and escape to the opposite side. The expected electromagnetic shielding effect cannot be obtained in the surrounding area of the window glass 1 where the linear antenna element 5 ′ serving as the ineffective element occupies the position.

As shown in FIG. 18, if the linear antenna element 5 is not provided in the area surrounding the window glass 1 and inside the pocket of the metal sash frame 2, the linear antenna element 5 can be Although it is possible to prevent the metal sash frame 2 from entering the pocket, in this case, the interval between the arrangement surface of the linear antenna element 5 and the metal sash frame 2 is increased, and the conductive sash frame 2 is brought into contact with the metal sash frame 2. This space must be filled with the membrane 6. Such an arrangement of the conductive film 6 makes the arrangement pattern of the elements difficult and extremely troublesome.

It is also considered to make the sealing material 9 conductive as shown in Japanese Patent Application Laid-Open No. 3-31094 or the like to seal the inside of the metal sash frame 2 with this (see FIG. 3). However, this conductive sealing material 9 short-circuits the linear antenna element 5 'and the adjacent linear antenna element 5, and has no meaning in securing the electromagnetic shielding effect only by increasing the number of defective elements. . Further, the conductive sealing material 9 is expensive and difficult to construct. FIG.
Reference numeral 11 denotes a backup ring.

An object of the present invention is to solve the inconvenience of the prior art, and to connect a linear sash frame to a metal sash frame by disposing a linear sash frame and a metal sash frame. Even if you get into your pocket,
An object of the present invention is to provide a window structure having an electromagnetic shielding performance capable of securing an electromagnetic shielding performance around a window glass by adding a simple configuration to prevent the element from becoming an invalid element.

[0016]

According to the present invention, a linear antenna element having a length resonating with a radio wave to be shielded is used as an electromagnetic shielding element. In order to fit a regularly arranged window glass into a metal sash frame in consideration of the aperture area) or the electromagnetic field reflection equivalent volume (scattering aperture volume), a radio wave absorber is inserted between the window glass and the metal sash frame. It is intended to be filled.

According to the present invention, by filling the radio wave absorber between the window glass and the metal sash frame, the insertion loss of the radio wave absorber is firstly large, and the insertion loss is large.
In addition, the resonance coefficient: Q = ωL / R (resistance) is reduced, and it becomes difficult to resonate, the metallic sash at the glass end is eliminated, and the radio wave is released as if the glass end were at the same level as free space. And the same state.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional side view of a main part showing an embodiment of a window structure having electromagnetic shielding performance of the present invention, FIG. 2 is a perspective view of the same, and FIG. 1 shows a window glass, 2 shows a metal sash frame, The windowpane 1 has a linear antenna element 5 having a length corresponding to the frequency of a radio wave to be shielded, which is regularly arranged on the windowpane 1 in consideration of an electromagnetic reflection equivalent area or volume. At 5, the radio wave is attenuated.

The linear antenna element may be a ring-shaped element or a combination of an open-ended element and a ring-shaped element in addition to the open-ended element as described above.

In the drawing, reference numeral 7 denotes a setting block for fixing the window glass 1 in the pocket of the metal sash frame 2. As if holding down,
In the present embodiment, both sides of the gap between the window glass 1 and the metal sash frame 2 in the pocket are filled with the radio wave absorber 8. In the figure, 10 is a sealing material, and 11 is a backup ring.

Such a radio wave absorber 8 is a dielectric material having radio wave absorption properties, such as carbon rubber / carbon-containing urethane foam, carbon-containing foam polystyrene, or environmental resistance (moisture resistance, impact resistance, etc.). And a rubber sheet in which carbon particles (carbon black) are mixed as a loss material into an epoxy-modified urethane rubber having excellent properties. "ECCOSORB" is a commercial product.
(Trade name of E & C Engineering Co., Ltd.) is preferable.

L of "ECCOSORB"
The characteristics of what is referred to as the S type 26 are shown in Table 1 below.

[0023]

In another embodiment, the radio wave absorber 8 may be filled in only one side of the gap between the window glass 1 and the metal sash frame 2 in the pocket.

In order to test the effect of the present invention, FIGS. 4 to 11 show a comparison with the case without the radio wave absorber 8 as shown in FIG. In this experimental device, glass of 600 mm in length and 8 mm in thickness was fitted into a metal sash frame with an opening of 560 mm in length and width, and a linear antenna element 5 was printed on the surface of this glass.
The metal sash frame had a pocket width of 30 mm, and the radio wave absorber 8 was inserted into one or both sides of the glass.

FIG. 4 shows vertical polarization of the antenna of the mobile phone in the vertical direction. The linear antenna element 5 is in the case where the antenna is in the vertical direction as shown in FIG. 18, and FIG. FIG. 6 shows a case where the antenna of the mobile phone is horizontal and the antenna is horizontal. FIG. 7 shows a case where the linear antenna element 5 is vertical and FIG. 7 shows a case where the antenna is horizontal. This is the case when inserted in

8 to 11 show the case where the radio wave absorber 8 is inserted on both sides of the glass. FIG. 8 shows a vertically polarized linear antenna element 5 and FIG. 9 shows a vertically polarized linear antenna element. 5 is horizontal, FIG. 10 is horizontal polarization, and the linear antenna element 5 is vertical,
FIG. 11 shows a case where the linear antenna element 5 is in the horizontal direction.

As can be seen from these measurement results, the effect of the insertion of the radio wave absorber 8 is reduced by about 17 dB as compared with the case where the radio wave absorber 8 is not inserted and the case where the radio wave absorber 8 is inserted only on one side. It turns out that it is effective.

It can be seen that a sufficient attenuation effect is obtained when the shielding performance is improved by about 30 dB when the radio wave absorber 8 is inserted on both sides as compared with the case where it is not inserted.

The radio wave absorber 8 may also serve as a backup ring, a setting block material, and the like.

[0031]

As described above, the window structure having the electromagnetic shielding performance of the present invention has a linear antenna element in which the linear antenna element is arranged to perform electromagnetic shielding and the metal sash frame is engaged. Even if an object gets into the pocket of a metal sash frame, adding a simple structure lowers the resonance coefficient in the pocket, eliminates the reflection of electromagnetic waves by metal, and makes the edge of the window glass as if it were a free open end. As a result, the electromagnetic shielding performance around the window glass can be ensured by preventing the linear antenna element from becoming an element that reduces the shielding performance.

[Brief description of the drawings]

FIG. 1 shows a window structure 1 having electromagnetic shielding performance according to the present invention.
It is a longitudinal side view which shows embodiment.

FIG. 2 shows a window structure 1 having electromagnetic shielding performance according to the present invention.
It is a perspective view showing an embodiment.

FIG. 3 is a vertical side view of the window structure when no radio wave absorbing material is arranged.

FIG. 4 is a graph showing a comparison between a case where the radio wave absorber is one-sided, a vertically polarized wave, and a vertical direction of a linear antenna element and a case where there is no radio wave absorber in an experiment for testing the effect of the present invention.

FIG. 5 is a graph showing a comparison between the case where the radio wave absorber is one-sided, the vertically polarized wave, and the horizontal direction of the linear antenna element and the case where there is no radio wave absorber in an experiment for testing the effect of the present invention.

FIG. 6 is a graph showing a comparison between a case where the radio wave absorber is one-sided, a horizontally polarized wave, and a vertical direction of a linear antenna element and a case where there is no radio wave absorber in an experiment for testing the effect of the present invention.

FIG. 7 is a graph showing a comparison between a case where the radio wave absorber is on both sides, a horizontally polarized wave, and a horizontal direction of the linear antenna element and a case where there is no radio wave absorber in an experiment for testing the effect of the present invention.

FIG. 8 is a graph showing a comparison between a case where the radio wave absorber is on both sides, a vertically polarized wave, and a vertical direction of the linear antenna element and a case where there is no radio wave absorber in an experiment for testing the effect of the present invention.

FIG. 9 is a graph showing a comparison between a case where the radio wave absorber is on both sides, a vertically polarized wave, and a horizontal direction of the linear antenna element and a case where there is no radio wave absorber in an experiment for testing the effect of the present invention.

FIG. 10 is a graph showing a comparison between a case where the radio wave absorber is on both sides, a horizontally polarized wave, and a vertical direction of the linear antenna element and a case where there is no radio wave absorber in an experiment for testing the effect of the present invention.

FIG. 11 is a graph showing a comparison between a case where the radio wave absorber is on both sides, a horizontally polarized wave, and a sideways linear antenna element and no radio wave absorber in an experiment for testing the effect of the present invention.

FIG. 12 is a perspective view of a window glass having electromagnetic shielding performance.

FIG. 13 is a front view of a main part of a window glass having electromagnetic shielding performance.

FIG. 14 is a perspective view when a conductor is a linear antenna element (short-circuit dipole).

FIG. 15 is an explanatory diagram of one electromagnetic field reflection equivalent area when a conductor is a linear antenna element (short-circuit dipole).

FIG. 16 is an explanatory diagram of an electromagnetic field reflection equivalent area of the second case where a conductor is a linear antenna element (short-circuit dipole).

FIG. 17 is a front view of a window glass on which linear antenna elements are arranged.

FIG. 18 is an explanatory view showing a conventional example in which the relationship between a metal sash frame and a linear antenna element in a window glass having electromagnetic shielding performance is considered.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Window glass 2 ... Metal sash frame 3 ... Linear antenna element 4 ... Linear antenna element 5, 5 '... Linear antenna element 5a ... Center 5b ... Side 6 ... Conductive film 7 ... Setting block 8 ... Radio wave absorber 9: Sealing material 10: Sealing material 11: Backup ring

Continued on the front page (72) Inventor ▲ Taka ▼ Shuichi Sakaichi 2-9-1-1, Tobita-shi, Chofu-shi, Tokyo Kashima Construction Co., Ltd. (72) Inventor Motoyasu Togashi 3-1 Shirayama, Aso-ku, Kawasaki-shi, Kanagawa Prefecture. 1-504

Claims (1)

[Claims] A linear antenna element having a length resonating with a radio wave to be shielded is used as an electromagnetic shielding element, and an electromagnetic field reflection equivalent area (scattering aperture area) or an electromagnetic field reflection equivalent volume (scattering aperture volume) of the element is used. A window structure with electromagnetic shielding performance characterized by filling a radio wave absorber between the window glass and the metal sash frame to fit the window glass regularly arranged in consideration of .