JP4175836B2 - Film antenna - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a film antenna used by being attached to a glass of a car.
[0002]
[Prior art]
As a kind of antenna for an in-vehicle radio receiver, a film antenna that is attached to a rear glass or the like is known. However, in recent years, not only in-vehicle radio receivers but also TV receivers and TV tuner units of car navigation units are often installed on the front console together with the image monitor. Therefore, in order to improve problems such as cable routing, it has been proposed to attach a film antenna to the windshield.
[0003]
However, if anything that obstructs the driver's field of view, such as a film antenna, is stuck on the windshield, it may interfere with safe driving. Accordingly, Article 29, Paragraph 4, Item 7 of the safety standard stipulates a range where a film antenna may be attached to the windshield. An example of the range permitted by this security standard is that the side edge of the windshield is within 25 mm from the vehicle frame. In addition, an inspection sticker or the like is also attached to the upper side of the windshield, and the range in which the film antenna can be disposed is extremely limited.
[0004]
For this reason, a conventional film antenna to be attached to the side edge of the windshield has to have a single linear antenna element arranged vertically along the side edge of the windshield. It ’s not good.
[0005]
[Problems to be solved by the invention]
In the above-described film antenna, the length of the windshield in the vertical direction is not sufficient, and the length of the range that can be used for an inspection seal having a conductive thin film is narrowed. It can only be set to about 400 mm. For this reason, AM / FM broadcast waves cannot be received with high gain, and TV broadcast waves cannot be received sufficiently. Furthermore, FM multiplex broadcast waves including traffic information broadcasting such as VICS cannot be received satisfactorily.
[0006]
The present invention has been made in order to improve the problems of the conventional film antenna as described above, and can receive various broadcast waves with high gain even if it is pasted within the range defined by the safety standards. An object of the present invention is to provide a film antenna.
[0007]
[Means for Solving the Problems]
To achieve the above object, a film antenna of the present invention, there is provided a film antenna to be affixed vertically to the edge of the lateral of the vehicle frame side of the windshield of the car, one side adhesive layer is disposed a long transparent film has been machine direction, with disposing the narrow conductive film or a thin conductive wire having a width in the vertical direction, the narrow conductive film or narrow end of the width in the lower portion of the transparent film and the extension line as one side The conductive wire is arranged in a rectangular loop shape that is long in the vertical direction to form an antenna element, the upper end portion of the antenna element is bent to the side on which the rectangle is provided, and a feeding portion is provided at the tip thereof. The conductive film or conductive wire and one side of the rectangle are at a position 25 mm away from the vehicle frame as a conductor, and the rectangle and the feeding portion are on the vehicle frame side. A manner, and is configured so as to affixed the transparent film to the glass.
[0008]
Furthermore, a film antenna to be affixed vertically to the edge of the lateral of the vehicle frame side of the windshield of the car, a long transparent film longitudinally adhesive layer is disposed on one side, narrow A rectangular shape in which a conductive film or a thin conductive line is arranged in a crank shape in the vertical direction, and the narrow conductive film or a thin conductive line is long in the vertical direction on the lower portion of the transparent film with the extended line as one side An antenna element is arranged on the crank-shaped upper portion side in a loop shape, and a feeding portion is provided at the crank-shaped upper end portion of the antenna element, and a part of the crank shape in the vertical direction and one side of the rectangle At a position 25 mm away from the vehicle frame as a conductor so that the rectangle and the crank-shaped upper portion and the power feeding portion are on the vehicle frame side. The transparent film may be configured so as to stuck to.
[0009]
Further, the length of the antenna element in the vertical direction can be set to about 400 mm, and the length and width of the rectangle can be set to 70 mm and 20 mm, respectively.
[0010]
Furthermore, while affixed to the transparent film on the front glass, the film antenna, wherein the feeding portion is configured to face the masking portion of the peripheral edge of the windshield.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view of a first embodiment of the film antenna of the present invention. FIG. 2 is an enlarged view taken along the line AA in FIG. 3 is an enlarged view taken along the line B-B in FIG. 1. FIG. 4 is an enlarged partial view of the feeding portion of the film antenna of the present invention shown in FIG. FIG. 5 is a view showing a state in which the film antenna of the first embodiment of the present invention shown in FIG. 1 is attached to the side edge of the windshield of the car. FIG. 6 is an antenna characteristic diagram of the film antenna of the present invention shown in FIG. FIG. 7 is an antenna characteristic diagram of a film antenna in which the length of the rectangle is changed from 70 mm to 140 mm. FIG. 8 is an antenna characteristic diagram of a film antenna in which the dimension in the width direction of the rectangle is changed from 20 mm to 25 mm.
[0012]
A conductive film having a narrow width of 0.25 mm or less is arranged on the surface of the transparent film 10 which is made of an insulating material and which is long in the vertical direction, and the lower portion of the transparent film 10 with the extended line as one side. The antenna element 12 is formed in a closed rectangular loop shape that is long in the vertical direction. The upper end portion of the conductive film is bent to the side where the rectangle is provided, and a power feeding portion 14 is formed at the tip. The conductive film forming the antenna element 12 and the power feeding unit 14 is appropriately formed by printing conductive ink or the like. In addition, a transparent resist 16 is disposed on the conductive film except for the power supply unit 14 as shown in FIGS. 2 to 4 to protect the conductive film. An adhesive layer 18 is disposed on the back surface of the transparent film 10, and a release sheet 20 is provided so as to cover the adhesive layer 18.
[0013]
Here, the adhesive layer 18 is transparent, and may be composed of a transparent double-sided tape. The release sheet 20 may be either transparent or opaque. Further, the conductive film forming the antenna element 12 is opaque in the above-described embodiment, but may be transparent. Moreover, instead of the conductive film, a thin conductive wire may be used and fixed to the transparent film 10 as appropriate.
[0014]
The dimensions of the first embodiment of the film antenna of the present invention are as follows. The total length in the vertical direction of the antenna element 12 is 381 mm, which is about 400 mm, and the vertical and horizontal dimensions of the rectangle are 70 mm and 20 mm. The bending length of the upper end part to the power feeding part 14 is 27 mm.
[0015]
As shown in FIG. 5, the film antenna of the present invention having such a structure is attached to the edge of the inner surface of the windshield 24 on the side of the vehicle frame 30 by peeling the release sheet 20 and sticking the adhesive layer 18. From the vehicle frame 30 as a conductor, the vertical conductive film and one side of the rectangle are located so as to be 25 mm away from the specified range of the safety standard, and the rectangle is on the vehicle frame 30 side. Established. And the electric power feeding part 14 is stuck facing the masking (common name, black sera) part 32 provided in the peripheral part of the windshield 24. FIG. Further, a power supply connector 34 is disposed so that a spring connector is elastically contacted with the power supply unit 14, and the antenna element 12 is appropriately electrically connected to a receiver and a tuner.
[0016]
FIG. 6 shows the antenna characteristics measured by attaching the film antenna of the present invention to the windshield 24 as shown in FIG. As is apparent from FIG. 6, the film antenna of the present invention has a band centered on 92 MHz, and can be used as a receiving antenna for FM broadcast waves, FM multiple information waves, and TV VHF-LOW bands.
[0017]
By the way, FIG. 7 and FIG. 8 show how the antenna characteristics change depending on the rectangular size of the lower part of the antenna element 12. FIG. 7 shows the antenna element 12 whose rectangular length is changed from 70 mm to 140 mm. The center frequency is slightly reduced to about 90 MHz. This is presumed to be due to the fact that the distance attached to the vehicle frame 30 is increased by increasing the longitudinal length of the rectangle, and the coupling capacity with the vehicle frame 30 is increased. The As a result, if the length of the rectangle in the vertical direction is shortened, the center frequency is predicted to increase. FIG. 8 shows the antenna element 12 whose rectangular width is changed from 20 mm to 25 mm. The center frequency is greatly reduced to about 70 MHz. This is presumably due to the fact that one side of the rectangle is close to the vehicle frame 30, thereby increasing the coupling capacity with the vehicle frame 30. As a result, it is predicted that if the width of the rectangle is narrowed and the distance from the vehicle frame 30 is increased, the coupling capacity decreases and the center frequency increases. Based on the knowledge obtained from the measurements shown in FIG. 7 and FIG. 8, the film antenna of the present invention is pasted on the windshield 24, and the range and length that can be pasted are restricted. By appropriately setting the vertical and horizontal dimensions, it is possible to obtain antenna characteristics in a desired center frequency band.
[0018]
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a front view of a second embodiment of the film antenna of the present invention. FIG. 10 is a view showing a state in which the film antenna of the second embodiment of the present invention shown in FIG. 9 is attached to the side edge of the windshield of the car. 9 and 10, the same or equivalent members as those in FIGS. 1 to 5 are denoted by the same reference numerals, and redundant description is omitted.
[0019]
In the second embodiment, the difference from the first embodiment is that the conductive film is arranged in a crank shape in the vertical direction on the surface of the transparent film 10 which is long in the vertical direction, and the extension line is one side of the transparent film 10. The antenna element 42 is formed by arranging the conductive film in the lower portion in a closed rectangular loop shape that is long in the vertical direction . Note that the crank-shaped upper portion is on the side where the rectangle is disposed, and the power supply unit 14 is provided at the crank-shaped upper end.
[0020]
And as shown in FIG. 10, it arrange | positions so that it may be 25 mm away from the vehicle frame 30 at the edge of the side of the windshield 24 by the side of the vehicle frame 30 side. Here, the crank-shaped upper portion and the power feeding portion 14 are attached so as to face the masking portion 32. In the state where the broadcast wave is received, the upper part of the antenna element 42 does not become a large voltage, and even when the antenna element 42 is close to the vehicle frame 30, the large capacitive coupling does not occur, and the antenna characteristics do not change greatly. Antenna characteristics similar to those of the first embodiment can be obtained.
[0021]
In the above embodiment, it has been described that the film antenna of the present invention is attached to the side edge of the windshield 24. However, the present invention is not limited to this, and the side edge of the rear glass is attached to the edge. Of course, it is also possible to use it. Furthermore, it can be attached to the side glass of a car. Moreover, in the said Example, although the antenna element 12 was provided in the surface of the transparent film 10, and the adhesive bond layer 18 was provided in the back surface, the antenna element may be provided in any surface of the transparent film 10. FIG. And the adhesive bond layer 18 should just be provided in the single side | surface of the transparent film 10. FIG. Further, the antenna element 12 may be disposed so as to be sandwiched between two transparent films.
[0022]
【The invention's effect】
As described above, since the film antenna of the present invention is configured, the following advantageous effects can be obtained.
[0023]
The film antenna according to claim 1 can be attached to the edge of the side of the windshield next to the vehicle frame within a range regulated by the safety standard of the windshield of the vehicle . Then, by appropriately setting the vertical and horizontal dimensions of the loop-shaped rectangle provided in the lower part of the antenna element, antenna characteristics in a desired center frequency band can be obtained, and FM broadcast waves and FM multiplexed information waves can be obtained. For example, it is possible to set a good antenna characteristic. In addition, since the feeding portion and one side of the long side of the loop-shaped rectangle are disposed on the vehicle frame side, these portions are assimilated with the vehicle frame, as if the upper portion of the antenna element and the loop-shaped It is visually recognized as an elongated E-shape that is long in the longitudinal direction of only one long side and two short sides of the rectangle, and does not interfere with the field of view.
[0024]
The film antenna according to claim 2 has the same effect as that of claim 1, and the crank-shaped upper portion, the power feeding portion, and one side of the long side of the loop-shaped rectangle are arranged on the vehicle frame side. Therefore, these parts are seen assimilated with the vehicle frame, and are small reverse E characters that are short in the vertical direction of only the long side and the short side of the long side of the crank-like lower part and the loop-like rectangle. It does not interfere with the field of view.
[0025]
The film antenna according to claim 3 is 400 mm in the vertical direction, and can be used for a light vehicle having a short size in the vertical direction of the windshield.
[0026]
Film antenna according to claim 4, since the power supply portion is affixed to the masking portion of the peripheral edge of the windshield, the power feeding connector for electrically connecting the feeding portion and thereto, hidden by a masking portion from the car outside Excellent in aesthetics.
[Brief description of the drawings]
FIG. 1 is a front view of a first embodiment of a film antenna of the present invention.
FIG. 2 is an enlarged view taken along the line AA in FIG.
FIG. 3 is an enlarged view taken along the line BB in FIG. 1;
4 is an enlarged partial view of a feeding portion of the film antenna of the present invention shown in FIG.
FIG. 5 is a view showing a state in which the film antenna of the first embodiment of the present invention shown in FIG. 1 is attached to the side edge of the windshield of the car.
6 is an antenna characteristic diagram of the film antenna of the present invention shown in FIG. 1. FIG.
FIG. 7 is an antenna characteristic diagram of a film antenna in which the length of a rectangle is changed from 70 mm to 140 mm.
FIG. 8 is an antenna characteristic diagram of a film antenna in which a rectangular width dimension is changed from 20 mm to 25 mm.
FIG. 9 is a front view of a second embodiment of the film antenna of the present invention.
FIG. 10 is a view showing a state in which the film antenna of the second embodiment of the present invention shown in FIG. 9 is attached to the side edge of the windshield of the car.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Transparent film 12,42 Antenna element 14 Feed part 16 Resist 18 Adhesive layer 20 Release sheet 24 Windshield 30 Vehicle frame 32 Masking part 34 Feed connector

Claims (4)

A film antenna to be affixed vertically to the edge of the lateral of the vehicle frame side of the windshield of the car, a long transparent film longitudinally adhesive layer is disposed on one side, a narrow conductive film width Alternatively, a thin conductive wire is arranged in the vertical direction, and the narrow conductive film or the thin conductive wire is arranged in a closed rectangular loop extending in the vertical direction on the lower portion of the transparent film with the extended line as one side. The antenna element is provided, the upper end portion of the antenna element is bent to the side where the rectangle is provided, and a feeding portion is provided at the tip thereof, and the vertical conductive film or conductive line and one side of the rectangle are connected to the conductor. The transparent film can be pasted on the glass at a position 25 mm away from the vehicle frame so that the rectangle and the power feeding portion are on the vehicle frame side. Film antenna, characterized in that form have. A film antenna to be affixed vertically to the edge of the lateral of the vehicle frame side of the windshield of the car, a long transparent film longitudinally adhesive layer is disposed on one side, a narrow conductive film width Alternatively, a narrow rectangular loop in which thin conductive wires are arranged in a crank shape in the vertical direction and the narrow conductive film or the thin conductive wires are long in the vertical direction on the lower portion of the transparent film with the extended line as one side. The antenna element is arranged on the crank-shaped upper part side, and a feeding portion is provided at the crank-shaped upper end of the antenna element, and the vertical crank-shaped part and one side of the rectangle are At a position 25 mm away from the vehicle frame as a conductor, the rectangle and the crank-shaped upper part and the power feeding part are on the vehicle frame side, and the front of the glass Film antenna, characterized in that to constitute a transparent film so as to stuck.   3. The film antenna according to claim 1, wherein the length of the antenna element in the longitudinal direction is set to about 400 mm, and the length and width of the rectangle are set to 70 mm and 20 mm, respectively. . In the film antenna according to claim 1, wherein, while affixed to the transparent film on the front glass, the film antenna, wherein the feeding portion is configured to face the masking portion of the peripheral edge of the windshield.

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