JPS58221503A - Electric wave reflector - Google Patents

Abstract

PURPOSE:To avoid giving an evil effect to illumination, etc., by providing a linear conductor to a transparent substrate with a space which is small sufficiently compared with the wavelength of an electric wave to be reflected in order to transmit visible light beams and to reflect an electric wave of an ultra- high frequency. CONSTITUTION:A linear conductor 4 is formed on a transparent substrate 3 of polyester, etc. by means of a metallic thin film, and an adhesive mass 5 is provided at the opposite side to the conductor 4. Thus the substrate 3 can be stuck to the window glass, etc. An electric wave of an ultra-high frequency is reflected by the mesh type conductor 4 while a visible light beam is transmitted. It is desirable to use a thin film of a good conductor like copper, aluminum, nickel, etc. to produce the conductor 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a radio wave reflecting device that transmits visible light and reflects ultra-high frequency radio waves.

Prior Art and Problems Recently, with the development of microwave and millimeter wave communications, there has been an increasing demand for installing radio wave reflecting devices inside or on the walls of buildings to change the propagation path of radio waves. Conventional radio wave reflecting devices use metal plates, so visible light does not pass through them, so if they are installed near a window, the room will be (1) dark; There was a drawback that affected indoor lighting. Furthermore, when communicating using microwaves indoors, the radio waves leak outside through ordinary window glass, making it impossible to maintain confidentiality.

OBJECTS OF THE INVENTION The present invention aims to reflect ultra-high frequency radio waves but allow visible light to pass through so as not to affect illumination or the like. Examples will be described in detail below.

Embodiment of the Invention FIG. 1 is a plan view of an embodiment of the invention, showing a case where linear conductors 2 are arranged in a mesh shape on a transparent substrate l. FIG. 2 is a cross-sectional view of an example of the transparent substrate 3 made of polyester or the like.
A linear conductor 4 made of a metal thin film is provided on the side, and an adhesive 5 is provided on the opposite side so that it can be bonded to a window glass or the like. FIG. 3 shows a sectional view of another example, in which a linear conductor 8 is interposed between glass plates 6 and 7.

(2) Ultra-high frequency radio waves are reflected by the mesh-like linear conductor, while visible light is transmitted.

It is desirable that the linear conductor be made of a thin film of a good conductor such as copper, aluminum, or nickel;
Since it can transmit more light, it does not affect illumination or the like.

FIG. 4 is a plan view of another embodiment of the present invention, showing a case where linear conductors 9 are arranged in parallel on a transparent substrate l. When the linear conductors 9 are arranged in parallel in this way, polarization selectivity is achieved. In other words, the polarized waves parallel to the linear conductor 9 are reflected because the current flows through the linear conductor, creating a short-circuit with respect to the polarized waves. The waves will be transmitted almost unaffected.

In each of the embodiments described above, the arrangement interval a of the linear conductors is determined in relation to the wavelength λ of the radio wave, and the relationship a<<λ/2 holds. The embodiment shown in FIG. 4 can also have the cross-sectional configuration shown in FIGS. 2 and 3.

(3) The linear conductor can be easily manufactured by employing a known method of forming a conductor film on plastic or glass.

FIG. 5 shows an application example of the radio wave reflecting device according to the embodiment of the present invention, in which the radio wave number transmitted from the ultra-high frequency transmitting/receiving device 12 via the antenna 11 is transmitted through the window glass 13 to the outside. radio wave reflecting device 10 installed outside the window.
The light is reflected and propagated downward parallel to the building wall. Furthermore, radio waves from below are reflected by the radio wave reflection device 10 and are incident on the antenna 11. Furthermore, as the natural light is transmitted through the radio wave reflecting device 10 and enters the room as shown by the two-dot chain line, the room does not become dark. Note that 14 indicates a desk.

In this way, the radio wave reflecting device 10 installed outside the window serves as an eaves, and the window glass 13 does not get wet during rain, so the radio waves transmitted through the window glass 13 are attenuated by the rainwater. There are no advantages. This radio wave reflecting device 1O can be bonded to a glass plate using the adhesive 5 having the cross-sectional structure shown in (4) in FIG. The conductors can be mesh-shaped as shown in FIG. 1 or parallel-shaped as shown in FIG.

FIG. 6 is an explanatory diagram applied to ultra-high frequency communication indoors, in which radio waves transmitted from the ultra-high frequency transmitter/receiver 16 on the desk 18 via the antenna 15 are sent to the radio wave reflector 10 attached to the ceiling. The signal is reflected by the antenna, propagates along the ceiling, is reflected by another radio wave reflecting device, and is emitted to an antenna (not shown) on another desk. Fluorescent light 17 attached to the ceiling
Since the illumination light from the desk passes through the radio wave reflection device 10 and is irradiated onto the desk 18, even if the radio wave reflection device 10 is installed above the desk 18, the desk top will not become dark.

FIG. 7 is an explanatory diagram when the radio wave reflection device 10 is attached to the window of a building, and the radio waves between the antennas 20 and 21 are reflected and propagated by the radio wave reflection device 10 attached to the window of another building. (5) It is possible to communicate between different floors of a building. In addition, when communicating between indoor antennas 22 and 23, even if radio waves leak toward the core, there is a radio wave reflecting device IO in the window.
By installing this, the radio waves will not be leaked to the outside, so it will be possible to maintain confidentiality.

As described in detail, the present invention has a configuration that reflects ultra-high frequency radio waves and transmits light. Therefore, when a radio wave reflection device is installed indoors or outdoors, it is possible to prevent the incidence of natural light. There is an advantage that there is no disturbance or interference with illumination caused by illumination lights. Therefore, even if it is mounted on a desk or window, it will not affect indoor lighting due to the reflection of radio waves for ultra-high frequency communication indoors or from indoors via outdoor 1. Moreover, since it can also be used as window glass, it has the advantage of being economical, and has the advantage of making it possible to maintain the confidentiality of indoor communications.

[Brief explanation of drawings]

1 and 4 are plan views of different embodiments of the present invention (6), FIGS. 2 and 3 are sectional views of different embodiments of the present invention, and FIGS. 5 to 7 are FIG. 3 is an explanatory diagram of an application example of the radio wave reflecting device of the present invention. 1 is a transparent substrate, 2, 4, 8.9 are linear conductors, 3 is a transparent substrate such as polyester, 5 is an adhesive, 6°7 is a glass plate,
10 is a radio wave reflecting device, 11, 15. 20. 21, 22.
23 is an antenna. Patent Applicant: Fujitsu Ltd. Representative Patent Attorney Gobe Tamamushi and 3 others (7) Figure 1, Figure 6, Figure 7

Claims (1)

[Claims] +11 A radio wave reflecting device characterized in that linear conductors are arranged on a transparent substrate at sufficiently narrow intervals compared to the wavelength of the radio waves to be reflected. (2) The radio wave reflecting device according to claim 1, wherein the linear conductor is a transparent metal thin film.