JP2023012829A - Electromagnetic wave transmission cover - Google Patents

Abstract

To cope with both of uniformity in the heat generation distribution and improvement of appearance.SOLUTION: A heater film 25 of a mm-wave transmission cover 20 as an electromagnetic wave transmission cover includes a conductive part 32 formed of a conductive material. A first electrode part 40 and a second electrode part 45 of the conductive part 32 are positioned in places that are outside a mm-wave transmission area Z1 and oppose while sandwiching the transmission area Z1, and are extended in a direction that crosses the opposing directions each. Each of multiple heater wire parts 51, 55 of the conductive part 32 has first ends 53, 58 and second ends 54, 62. The first ends 53, 58 for the respective heater wire parts 51, 55 are connected to the first electrode part 40, and the second ends 54, 62 are connected to the second electrode part 45. The first electrode part 40 and the second electrode part 45 have a line width wider than line widths of the heater wire parts 51, 55.SELECTED DRAWING: Figure 3

Description

TECHNICAL FIELD The present invention relates to an electromagnetic wave transmission cover that covers a device that transmits and receives electromagnetic waves such as millimeter waves from the front in the transmission direction of electromagnetic waves.

In a vehicle equipped with a device for transmitting and receiving electromagnetic waves such as millimeter waves, the device transmits electromagnetic waves to the outside of the vehicle. Electromagnetic waves reflected by objects outside the vehicle, including preceding vehicles, pedestrians, etc., are received by the device. Then, the device recognizes the object from the transmitted and received electromagnetic waves, and detects the distance between the vehicle and the object, the relative speed, and the like.

In the vehicle, an electromagnetic wave transmission cover that transmits electromagnetic waves is arranged in front of the device in the transmission direction of electromagnetic waves. The electromagnetic wave transmission cover has a layer structure in which a plurality of layers are laminated in the transmission direction, and covers the device from the front in the transmission direction.

Here, when ice and snow adhere to the electromagnetic wave transmission cover, the electromagnetic waves are attenuated, and there is a problem that the detection performance of the device is lowered. Therefore, an electromagnetic wave transmission cover with a heater film added has been proposed (see, for example, Patent Document 1).

The heater film has a conductive portion made of a conductive material. The conductive portion includes an electrode portion and a heater wire portion connected to the electrode portion. The heater wire portion includes a plurality of linear portions spaced apart from each other, and an arc-shaped connecting portion that connects the ends of the adjacent linear portions.

According to the electromagnetic wave transmission cover, when power is supplied to the conductive portion, the heater wire portion generates heat. Therefore, even if ice and snow adhere to the electromagnetic wave transmission cover, it is possible to melt the ice and snow by the heat generated by the heater wire portion, thereby suppressing attenuation of electromagnetic waves caused by the adhesion of ice and snow.

Japanese Patent No. 6719506

However, in the electromagnetic wave permeable cover described in Patent Document 1, if the electrode portion has a line width similar to that of the heater wire portion, the electrode portion may generate heat in the same manner as the heater wire portion when energized. be. In this case, it is difficult to generate heat with a uniform heat distribution in the area of the heater film that is desired to generate heat. Further, in the electromagnetic wave transmission cover described in Patent Document 1, the line width of the heater wire portion is as large as 50 μm to 70 μm.

An electromagnetic wave transmission cover that solves the above problems is applied to a vehicle equipped with a device that transmits and receives electromagnetic waves, is arranged in front of the device in the transmission direction of the electromagnetic wave, and has a plurality of layers laminated in the transmission direction. and one of the layers is a heater film, the heater film includes a conductive portion made of a conductive material, and the conductive portion includes , a plurality of heater wire portions, a first electrode portion and a second electrode portion, wherein the first electrode portion and the second electrode portion are outside the transmission region of the electromagnetic wave and sandwich the transmission region When the direction in which the first electrode portion and the second electrode portion face each other is defined as the facing direction, and the direction crossing the facing direction is defined as the crossing direction, the first electrode portion and the Each of the second electrode portions extends in the intersecting direction, each of the plurality of heater wire portions has a first end and a second end, and the first end of each heater wire portion is The second end of each heater wire portion is connected to the second electrode portion, and the first electrode portion and the second electrode portion are connected to the heater wire portion. It has a line width larger than the line width.

According to the above configuration, in the conductive portion of the electromagnetic wave permeable cover, when current flows in the order of the first electrode portion, the plurality of heater wire portions, and the second electrode portion, or vice versa, the second electrode portion and the plurality of heater wires Each heater wire portion generates heat when current flows through the portion and the first electrode portion in this order.

Here, the first electrode portion and the second electrode portion are positioned outside the electromagnetic wave transmission region and opposed to each other with the transmission region interposed therebetween, and extend in a crossing direction that intersects the opposing direction. there is Each of the plurality of heater wire portions is formed between the first electrode portion and the second electrode portion, is connected to the first electrode portion at the first end portion, and is connected to the second electrode portion at the second end portion. It is Thus, the plurality of heater wire portions are formed over a wide area. Therefore, it is possible to heat a wide area of the heater film.

Further, since the plurality of heater wire portions are connected in parallel to the first electrode portion and the second electrode portion, the same voltage is applied to each heater wire portion. Therefore, each heater wire portion can be uniformly heated.

Furthermore, since each line width of the first electrode portion and the second electrode portion is larger than the line width of the heater wire portion, each resistance of the first electrode portion and the second electrode portion is smaller than the resistance of the heater wire portion. . Even if the first electrode portion and the second electrode portion generate heat, they do not generate as much heat as the heater wire portion. Therefore, the heater film can generate heat with a uniform heat generation distribution by the heater wire portion.

Moreover, the line width of each heater wire portion can be made smaller than when the heater wire portion is connected in series with the first electrode portion and the second electrode portion. Also, by increasing the number of heater wire portions, it is possible to reduce the line width of each heater wire portion.

As the line width of the heater wire portion becomes smaller, the heater wire portion becomes less visible, and the appearance of the heater film and, by extension, the electromagnetic wave transmission cover is improved.
In the electromagnetic wave permeable cover, it is preferable that a slit extending in the cross direction is formed in each of the first electrode portion and the second electrode portion.

According to the above configuration, the formation of the slits makes the first electrode portion and the second electrode portion less conspicuous than those in which the slits are not formed, thereby further improving the appearance.
In addition, there is a small difference in rigidity between a portion of the heater film where the first electrode portion and the second electrode portion are formed and a portion where the first electrode portion and the second electrode portion are not formed, particularly between the first electrode portion and the second electrode portion and the surrounding portions. Become. Therefore, it is possible to make the portion of the heater film where the first electrode portion and the second electrode portion are formed easier to bend.

In the electromagnetic wave permeable cover, each of the plurality of heater wire portions positioned at least in an intermediate portion in the crossing direction among the plurality of heater wire portions is entirely composed of a straight portion extending linearly in the facing direction. Preferably, the straight portions of each of the plurality of heater wire portions located at least in an intermediate portion in the intersecting direction extend in the opposing direction while being spaced apart in parallel to each other in the intersecting direction.

According to the above configuration, in the plurality of heater wire portions located at least in the intermediate portion in the crossing direction, the intervals between the adjacent linear portions are uniform in the opposing direction. Therefore, compared to the case where the intervals are different in the facing direction, it is possible to generate heat with a uniform heat generation distribution in the facing direction between the adjacent straight portions.

In addition, compared to the case where the intervals between adjacent straight portions are different in the facing direction, the same straight portions are less visible.
In the electromagnetic wave permeable cover, it is preferable that the linear portions are formed at regular intervals in the intersecting direction in the plurality of heater wire portions located at least in the middle portion in the intersecting direction.

According to the above configuration, in the plurality of heater wire portions located at least in the intermediate portion in the cross direction, the intervals between the adjacent linear portions are uniform in the cross direction. Therefore, compared to the case where the intervals between the adjacent linear portions are different in the cross direction, it becomes easier to heat the heater film with a uniform heat generation distribution in the cross direction.

In addition, the plurality of linear portions are evenly arranged in the crossing direction, and the heater wire portion is less visible than when the intervals between the adjacent linear portions are different in the crossing direction.
In the electromagnetic wave permeable cover, one of the first electrode portion and the second electrode portion is curved so as to bulge away from the other, and the other is curved so as to bulge away from the one. Of the heater wire portions, the heater wire portions positioned on both sides in the intersecting direction are preferably formed to be longer than the case where the whole extends linearly in the opposing direction.

When the first electrode portion and the second electrode portion are curved as described above, the distance between the two electrode portions is widest at the central portion in the cross direction. The interval becomes narrower as it goes away from the central portion in the cross direction.

Along with this, the straight portion of the heater wire portion becomes longer at the central portion in the cross direction than at other portions. The length of the straight portion becomes shorter as it goes away from the central portion in the cross direction. As the length becomes shorter, the amount of heat generated by the heater wire portion becomes smaller. The heat generation has a distribution in which the amount of heat generation is large in the central portion in the cross direction, and the amount of heat generation decreases as the distance from the center portion in the cross direction increases.

In this regard, according to the above configuration, among the plurality of heater wire portions, the heater wire portions positioned on both sides in the cross direction are formed longer than in the case where the whole extends linearly in the facing direction. By increasing the length as described above, the amount of heat generated by the heater wire portion on both sides increases. Accordingly, variations in heat generation distribution in the cross direction are reduced.

In the electromagnetic wave permeable cover, the heater wire portions positioned on both sides in the intersecting direction are linear portions extending linearly in the opposing direction outside the first electrode portion and the second electrode portion in the intersecting direction. a first extension portion extending from one end of the linear portion toward the first electrode portion and having the first end; and a second extension extending toward and having said second end, said first extension being connected at said first end to said first electrode portion, said second extension being said second extension. It is preferable that the two end portions are connected to the second electrode portion.

According to the above configuration, the heater wire portions located on both sides in the cross direction are composed of the linear portion, the first extension portion, and the second extension portion. The heater wire portions on both sides are longer by the length of the first extension portion and the second extension portion compared to the case where the heater wire portions are composed only of straight portions.

In addition, the length of the first electrode portion in the cross direction is shortened along with the formation of the first extension portion. Accordingly, the first electrode portion becomes inconspicuous, and the appearance is further improved. In addition, the length of the second electrode portion in the cross direction is shortened with the formation of the second extension portion. Accordingly, the second electrode portion becomes inconspicuous, and the appearance is further improved.

In the electromagnetic wave permeable cover, the conductive portion further includes a positive terminal portion and a negative terminal portion to which equipment for power supply is connected, and the first electrode portion is a first positive terminal portion connected to the positive terminal portion. and a first negative electrode part formed apart from the first positive electrode part and connected to the negative terminal part, wherein the first positive electrode part and the first negative electrode part are , adjacent to each other at least in the intersecting direction, and the second electrode portion serves as a relay electrode portion between the first positive electrode portion and the first negative electrode portion, the first positive electrode portion and the first negative electrode portion. The first ends of some of the heater wire portions facing the first negative electrode portions are connected to the first positive electrode portions, and the second end portions of the some of the heater wire portions are connected to the first positive electrode portions. The first end of the remaining heater wire portion is connected to the first negative electrode portion, and the second end of the remaining heater wire portion is connected to the second electrode portion. is preferably connected to

According to the above configuration, when power is supplied from the device to the conductive portion, the current is connected to the first positive electrode portion among the positive terminal portion, the first positive electrode portion, and the plurality of heater wire portions, and the second electrode portion. Further, the current flows through the second electrode portion, the heater wire portion connected to the first negative electrode portion, the first negative electrode portion, and the negative terminal portion in this order. The direction of current flowing from the first positive electrode portion toward the second electrode portion is opposite to the direction of current flowing from the second electrode portion toward the first negative electrode portion.

Therefore, it is possible to cause the current to flow evenly through the entirety of the plurality of heater wire portions. As a result, the heater film can generate heat with a more uniform heat distribution.

According to the electromagnetic wave permeable cover, it is possible to achieve both a uniform heat distribution and an improved appearance.

FIG. 4 is a partial front view showing the millimeter wave transmitting cover together with a part of the front grill in one embodiment in which the electromagnetic wave transmitting cover is embodied as a millimeter wave transmitting cover for vehicles. FIG. 2 is a partial plan cross-sectional view showing the millimeter wave transmission cover of the same embodiment together with a part of the millimeter wave radar device; FIG. 4 is a rear view of the heater film of the same embodiment, showing a state before a resist layer is formed; FIG. 4 is a partial rear view showing an enlarged portion A of FIG. 3 ; FIG. 4 is a partial rear view showing an enlarged portion B of FIG. 3 ; FIG. 4 is a partial rear view showing an enlarged portion C of FIG. 3 ; FIG. 4 is a partial rear view showing an enlarged portion D of FIG. 3 ; FIG. 4 is a partial rear view showing an enlarged portion E of FIG. 3 ; FIG. 4 is a partial rear view showing an enlarged portion F of FIG. 3 ; FIG. 4 is a partial rear view showing an enlarged portion G of FIG. 3 ; FIG. 7 is a partial rear view showing an enlarged portion H of FIG. 6 ; FIG. 8 is a partial rear view showing an enlarged portion I of FIG. 7 ; FIG. 11 is a partial rear view showing an enlarged portion J of FIG. 10; FIG. 11 is a partial rear view showing an enlarged portion K of FIG. 10;

An embodiment in which the electromagnetic wave transmission cover is embodied as a millimeter wave transmission cover for vehicles will be described below with reference to the drawings.
In the description below, the forward direction of the vehicle is defined as the front, and the reverse direction is defined as the rear. The vertical direction means the vertical direction of the vehicle, and the horizontal direction is the width direction of the vehicle, which coincides with the horizontal direction when the vehicle moves forward. Furthermore, in FIG. 2, the scale of each part of the millimeter-wave transmission cover is appropriately changed to show each part in a recognizable size.

As shown in FIGS. 1 and 2, a millimeter-wave radar device for forward monitoring is installed behind the front grille 11 at the center in the left-right direction of the front of the vehicle 10 as a device for transmitting and receiving electromagnetic waves. 13 is installed. In FIG. 2, only part of the millimeter wave radar device 13 is illustrated. The millimeter-wave radar device 13 has a function of transmitting millimeter waves in electromagnetic waves toward the front outside the vehicle and receiving the millimeter waves reflected by objects outside the vehicle. Millimeter waves refer to radio waves having a wavelength of 1 mm to 10 mm and a frequency of 30 GHz to 300 GHz.

In the present embodiment, as described above, since the millimeter wave radar device 13 transmits millimeter waves toward the front of the vehicle 10, the direction in which the millimeter waves are transmitted by the millimeter wave radar device 13 is the rearward direction of the vehicle 10. is the direction from to the front. The front in the transmission direction of the millimeter wave generally matches the front of the vehicle 10 , and the rear in the same transmission direction generally matches the rear of the vehicle 10 . Therefore, in the following description, the forward direction in the transmission direction of millimeter waves is simply referred to as "front", "front", etc., and the rearward direction in the same transmission direction is simply referred to as "rearward", "rear", etc.

The thickness of the front grille 11 is not uniform, like a general front grille. Moreover, in the front grille 11, a metal plating layer may be formed on the surface of the base material made of resin. The front grille 11 may interfere with transmitted or reflected millimeter waves. For this reason, in the front grille 11, a window 12 is opened in front of the millimeter wave radar device 13 in the millimeter wave transmission direction, and the millimeter wave transmission cover 20 is arranged here. The millimeter wave transmission cover 20 covers the millimeter wave radar device 13 from the front.

A main portion of the millimeter wave transmission cover 20 is configured by a cover body portion 21 . In FIG. 2, only part of the cover main body 21 is illustrated. When viewed from the front, the cover main body 21 has an elliptical shape in which the horizontal dimension is larger than the vertical dimension. The cover main body 21 is arranged in an upright state so that its front surface faces forward and its rear surface faces rearward. The front surface of the cover body portion 21 constitutes a design surface 22 .

A part of the area spaced inwardly from the outer peripheral edge of the cover main body 21 is a transmission area Z1 for millimeter waves transmitted from the millimeter wave radar device 13 (see FIG. 3).
The cover main body portion 21 has a layered structure in which a plurality of layers are laminated in the front-rear direction. The multiple layers comprise cover substrate 23 , heater film 25 and protector 70 . Next, each layer will be described.

<Cover base material 23>
The cover base material 23 is formed by resin molding using a resin material having millimeter wave permeability as electromagnetic wave permeability. The resin material used to form the cover base material 23 may be transparent or opaque. In this embodiment, the cover base material 23 is made of PC (polycarbonate) resin, but may be made of other resin material such as ABS (acrylonitrile-butadiene-styrene copolymer) resin.

<Heater film 25>
The heater film 25 is for adding a snow-melting function to the millimeter wave transmitting cover 20 and is arranged in front of the cover base material 23 . The heater film 25 is formed into a shape corresponding to the shape of the front surface of the cover base material 23 . The heater film 25 includes a film substrate 26 , an adhesive layer 31 , a conductive portion 32 and a resist layer 65 .

<Film substrate 26>
The film base material 26 is a portion forming a skeleton portion of the heater film 25 . The film substrate 26 is made of a transparent resin material that is transparent to millimeter waves. In this embodiment, the film substrate 26 is made of PET (polyethylene terephthalate) resin.

FIG. 3 shows heater film 25 before resist layer 65 is formed. As shown in FIGS. 2 and 3, the film substrate 26 has a main body portion 27 and a connection portion 29 . When viewed from the front, the body portion 27 has a shape corresponding to that of the cover body portion 21, that is, an elliptical shape that is larger in the horizontal direction than in the vertical direction. The upper portion 28U and the lower portion 28L of the edge portion 28 of the main body portion 27 are located outside the transmission region Z1 for millimeter waves and face each other with the transmission region Z1 sandwiched from both sides in the vertical direction.

Here, among the radial directions of the elliptical body portion 27, the direction approaching the center O (the intersection of the major axis and the minor axis) is called "inward", and the direction away from the center O is called "outward". . Also, the direction along the edge portion 28 of the main body portion 27 is referred to as the "circumferential direction".

As shown in FIG. 10 , the connecting portion 29 is a portion to which a device 82 for power supply is connected, and extends outward in the radial direction from a portion of the edge portion 28 of the main body portion 27 .
Further, as shown in FIG. 3, a portion of the lower portion 28L below the center O of the main body portion 27 is referred to as a "central portion 28C of the lower portion 28L".

In the present embodiment, the connecting portion 29 extends obliquely downward and leftward in the radial direction from a point shifted to the left with respect to the central portion 28C.
<Adhesive layer 31>
As shown in FIG. 2, the adhesive layer 31 has a function of adhering the conductive portion 32 to the film substrate 26, and is formed on the entire rear surfaces of the main body portion 27 and the connection portion 29 of the film substrate 26. It is As the adhesive layer 31, for example, a transparent film-like optical adhesive sheet called OCA (OPTICAL CLEAR ADHESIVE) can be used.

The "transparency" in the cover base material 23, the film base material 26, and the adhesive layer 31 includes not only colorless transparency but also colored transparency (colored transparency). This point also applies to the resin sheet 71 and the adhesive layer 72 of the protective portion 70, which will be described later.

<Conductive part 32>
The conductive portion 32 is made of foil made of a conductive material, such as copper foil or silver foil. The conductive portion 32 is adhered to the film substrate 26 via the adhesive layer 31 . As shown in FIGS. 3 and 10, the conductive portion 32 includes a pair of terminal portions, a first electrode portion 40 and a second electrode portion 45, and a plurality of heater wire portions 51 and 55. As shown in FIGS.

[Pair of terminals]
The pair of terminal portions is composed of a positive terminal portion 33 and a negative terminal portion 34 formed on the rear surface of the connection portion 29 with an adhesive layer 31 interposed therebetween.

As shown in FIGS. 13 and 14 , the positive terminal portion 33 and the negative terminal portion 34 intersect with a plurality of first conductor portions 35 arranged in parallel and spaced apart from each other. , and a plurality of second conductor portions 36 arranged in parallel and spaced apart from each other. In this embodiment, each first conductor portion 35 and each second conductor portion 36 are orthogonal to each other. A square mesh is formed by two adjacent first conductor portions 35 and two adjacent second conductor portions 36 . The positive terminal portion 33 and the negative terminal portion 34 have a mesh shape in which the meshes are arranged vertically and horizontally. The positive terminal portion 33 and the negative terminal portion 34 are separated from each other in the circumferential direction of the body portion 27 .

The connection portion 29 , the positive terminal portion 33 and the negative terminal portion 34 are bent rearward along the lower surface of the edge portion of the cover base 23 when assembled in the millimeter wave transmission cover 20 , although not shown.

As shown in FIG. 10, the extended end portion 33a of the positive terminal portion 33 and the extended end portion 34a of the negative terminal portion 34 are not covered with the resist layer 65 described later. A connector pin (not shown) is fixed to each of these extension ends 33a and 34a by fixing means such as soldering, adhesion, or crimping. Both extending ends 33a and 34a and both connector pins are arranged together with a part of the connection portion 29 of the film substrate 26 in a socket portion 81 arranged behind the cover substrate 23. As shown in FIG.

[First electrode part 40 and second electrode part 45]
As shown in FIGS. 3 and 10, the first electrode portion 40 and the second electrode portion 45 are formed on the edge portion 28 of the rear surface of the body portion 27 via the adhesive layer 31, respectively. The first electrode portion 40 and the second electrode portion 45 are located outside the transmission region Z1 for millimeter waves and face each other with the transmission region Z1 sandwiched from both sides in the vertical direction. The first electrode portion 40 is composed of a first positive electrode portion 41 and a first negative electrode portion 42 .

As shown in FIGS. 5, 7 and 12, the first plus electrode portion 41 extends substantially in the left-right direction along the lower portion 28L. The first positive electrode portion 41 is gently curved so as to expand downward. The first positive electrode portion 41 includes a narrow portion 41a and a wide portion 41b having a line width larger than that of the narrow portion 41a. The narrow portion 41a extends substantially leftward from the vicinity of the left side of the central portion 28C. The wide portion 41b extends substantially rightward from the vicinity of the left side of the central portion 28C.

As shown in FIGS. 3 and 10, the first positive electrode portion 41 is connected to the positive terminal portion 33 at the left end portion of the narrow portion 41a. The right end of the wide portion 41b is located near the right end of the body portion 27. As shown in FIG.

As shown in FIGS. 7, 9 and 10, the first negative electrode portion 42 extends substantially laterally along the lower portion 28L. The first negative electrode portion 42 is gently curved so as to expand downward. The first negative electrode portion 42 is connected to the negative terminal portion 34 at its intermediate portion in the direction along the lower portion 28L. As shown in FIGS. 3 and 9, the left end of the wide portion 42b is located near the left end of the body portion 27. As shown in FIGS.

As shown in FIGS. 7 and 10, the portion of the first negative electrode portion 42 to the right of the connection portion with the negative terminal portion 34 is constituted by a narrow portion 42a having a narrow line width. The right end portion of the narrow portion 42a is located leftwardly away from the central portion 28C and slightly leftwardly away from the wide portion 41b. A portion of the first negative electrode portion 42 to the left of the connection portion with the negative terminal portion 34 is constituted by a wide portion 42b having a line width larger than that of the narrow portion 42a.

As shown in FIGS. 10 and 12, the narrow portion 41a of the first positive electrode portion 41 and the narrow portion 42a of the first negative electrode portion 42 are arranged apart from each other in the radial direction.
On the other hand, as shown in FIGS. 3 and 6 , the second electrode portion 45 functions as a relay electrode portion between the first positive electrode portion 41 and the first negative electrode portion 42 . The second electrode portion 45 is formed via the adhesive layer 31 on the upper portion 28U of the edge portion 28 that faces the lower portion 28L with the transmissive region Z1 interposed therebetween. The second electrode portion 45 extends substantially in the horizontal direction along the upper portion 28U. The second electrode portion 45 is gently curved so as to expand upward. The line width of the second electrode portion 45 is uniform in the circumferential direction along the upper portion 28U. The right end of the second electrode portion 45 is located above the right end of the first positive electrode portion 41 . The left end of the second electrode portion 45 is positioned above the left end of the first negative electrode portion 42 .

As described above, the first electrode portion 40 and the second electrode portion 45 face each other in the vertical direction with the transmissive region Z1 interposed therebetween. Here, the direction along the rear surface of the body portion 27 and the direction in which the first electrode portion 40 and the second electrode portion 45 face each other is referred to as the "opposing direction". Also, the direction intersecting with the opposing direction is referred to as the "intersecting direction". The intersecting direction includes a direction perpendicular to the opposing direction and a direction obliquely intersecting. In the present embodiment, the cross direction corresponds to the substantially left-right direction, which is the direction substantially orthogonal to the facing direction.

As shown in FIGS. 12 and 13, each of the first positive electrode portion 41 and the first negative electrode portion 42 is formed with a plurality of slits 43 extending in the cross direction along the lower portion 28L. Each slit 43 extends substantially in the horizontal direction while gently curving downward. The slits 43 are formed at a plurality of locations in each of the first positive electrode portion 41 and the first negative electrode portion 42 in the direction along the lower portion 28L. The slits 43 adjacent to each other in the direction along the lower portion 28L are spaced apart in the same direction with a connecting portion 44 provided between both slits 43 . Also, the slits 43 are formed at a plurality of locations in each of the first positive electrode portion 41 and the first negative electrode portion 42 in the radial direction. The plurality of radial slits 43 are spaced apart in the same direction.

Here, a value obtained by subtracting the width of all the slits 43 from the actual line width of the wide portion 41b assuming that the slits 43 are not formed is the substantial line width of the first positive electrode portion 41. do. Similarly, a value obtained by subtracting the width of all the slits 43 from the actual line width of the wide portion 42b assuming that the slits 43 are not formed is the substantial line width of the first negative electrode portion 42. do. The actual line width and substantial line width of the first positive electrode portion 41 are larger than the line widths of heater wire portions 51 and 55, which will be described later. Similarly, the actual line width and the substantial line width of the first negative electrode portion 42 are also larger than the line widths of the heater wire portions 51 and 55 .

As shown in FIG. 11, the second electrode portion 45 is formed with a plurality of slits 46 extending in the cross direction along the upper portion 28U. Each slit 46 extends substantially in the horizontal direction while gently curving upward. The slits 46 are formed at multiple locations of the second electrode portion 45 in the direction along the upper portion 28U. The slits 46 that are adjacent to each other in the direction along the upper portion 28U are spaced apart in the same direction with a connecting portion 47 provided between both slits 46 interposed therebetween. Moreover, the slits 46 are formed at a plurality of locations of the second electrode portion 45 in the radial direction. The plurality of radial slits 46 are spaced apart in the same direction.

Here, a value obtained by subtracting the width of all the slits 46 from the actual line width of the second electrode portion 45 assuming that the slits 46 are not formed is the actual line width of the second electrode portion 45. and The actual line width and substantial line width of the second electrode portion 45 are larger than the line widths of the heater wire portions 51 and 55 .

[Several heater wire portions 51 and 55]
As shown in FIG. 3, the plurality of heater wire portions 51 and 55 have different shapes at the middle portion and both side portions in the cross direction.

As shown in FIGS. 3 and 7, the plurality of heater wire portions 51 positioned in the intermediate portion are entirely composed of linear portions 52 linearly extending in the facing direction. Each linear portion 52 is formed in a state of being spaced apart from each other in the crossing direction. The straight portion 52 of the heater wire portion 51 located in the central portion in the intersecting direction is located on or close to the center O.

As shown in FIGS. 6 and 7, each heater wire portion 51 has a first end 53 at its lower end and a second end 54 at its upper end. A first end portion 53 of each heater wire portion 51 is connected to the first electrode portion 40 . More specifically, some of the heater wire portions 51 , in this case, the heater wire portion 51 located in the central portion in the intersecting direction and the heater wire portion 51 located on the right side thereof, are located at the first end portion 53 It is connected to the first positive electrode portion 41 . The remaining heater wire portion 51 , in this case, the heater wire portion 51 located on the left side of the central portion in the cross direction is connected to the first negative electrode portion 42 at the first end portion 53 .

On the other hand, the second end portion 54 of each heater wire portion 51 is connected to the second electrode portion 45 .
As shown in FIG. 3, the distance between the first electrode portion 40 and the second electrode portion 45, which are curved so as to bulge in opposite directions, is widest at the center portion in the cross direction. The interval becomes narrower as it goes away from the central portion in the cross direction. At the central portion in the cross direction, the length of the heater wire portion 51 is longer than at other portions. The length of the heater wire portion 51 becomes shorter as it goes away from the central portion in the cross direction.

The heater wire portions 55 located on both sides in the cross direction, in this embodiment, two heater wire portions 55 on each side, are formed longer than when the whole extends linearly in the facing direction. . Each heater wire portion 55 is composed of a linear portion 56 , a first extension portion 57 and a second extension portion 61 . The linear portion 56 of each heater wire portion 55 extends linearly in the opposite direction outside the first electrode portion 40 and the second electrode portion 45 in the intersecting direction. Both ends of each linear portion 56 are positioned at the lower portion 28L and the upper portion 28U of the edge portion 28 .

The straight portions 56 of both heater wire portions 55 on each side are shorter than the straight portions 52 of any of the plurality of heater wire portions 51 . In addition, the length of both straight portions 56 for each side portion is shorter in the direction farther from the central portion in the cross direction.

A first extension portion 57 for each heater wire portion 55 extends from the lower end portion of the straight portion 56 toward the first electrode portion 40 along the lower portion 28L. Each first extension portion 57 is gently curved so as to swell downward to correspond to the lower portion 28L, and has a first end portion 58 . A first end portion 58 of each first extension portion 57 is laterally connected to the first electrode portion 40 . Adjacent first extensions 57 on the same side are separated from each other in the radial direction. Moreover, the both first extension portions 57 connected to the straight portion 56 farther from the central portion in the cross direction are longer.

A second extension portion 61 for each heater wire portion 55 extends from the upper end portion of the straight portion 56 toward the second electrode portion 45 along the upper portion 28U. Each second extension portion 61 is gently curved so as to bulge upward in correspondence with the upper portion 28U, and has a second end portion 62 . A second end portion 62 of each second extension portion 61 is laterally connected to the second electrode portion 45 . The second extension portions 61 adjacent to each other on the same side are separated from each other in the radial direction. Moreover, the two second extension portions 61 connected to the straight portion 56 farther from the central portion in the cross direction are longer.

By adding the first extension portion 57 and the second extension portion 61 as described above, the total length of the two heater wire portions 55 on each side is reduced to the heater wire portion located in the central portion in the cross direction. 51 is approaching the total length.

In this embodiment, the straight portions 52 and 56 of the plurality of heater wire portions 51 and 55 are formed at regular intervals in the intersecting direction. The interval between the adjacent linear portions 52, 56 is uniform in the cross direction. The interval between the adjacent linear portions 52 and 56 is preferably 2 mm or more in order to ensure millimeter wave transmittance. However, if the distance is excessively large, the heat generated by the linear portions 52 and 56 is less likely to be transferred to the central portion between the adjacent linear portions 52 and 56 . Therefore, the above-described interval is determined and set comprehensively from the viewpoints of securing required millimeter wave permeability, uniformity of heat generation distribution, resistance value, designability, and the like. In this embodiment, the interval is set to about 4 mm.

The line width of each heater wire portion 51, 55 is set to about 10 μm.
Heater wire portions are not formed in the main body portion 27 at both end portions in the cross direction, that is, in regions outside the heater wire portions 55 .

<Resist layer 65>
As shown in FIGS. 2 and 3, the resist layer 65 is made of an insulating material, and of the conductive portion 32, the extending end portion 33a of the positive terminal portion 33 and the extending end portion 34a of the negative terminal portion 34 are different. By covering the location, the same location is insulated. Both extending ends 33 a and 34 a are exposed from the resist layer 65 . The connector pins described above are fixed to this exposed portion in a conductive state.

<Production of heater film 25>
The heater film 25 having the above structure is manufactured as follows.
The adhesive layer 31 is formed by attaching the OCA to the rear surface of the film substrate 26 shown in FIG.

The film substrate 26 having the adhesive layer 31 formed thereon and the foil made of a conductive material, here copper foil, are pressed toward each other by a roller or the like. The foil is attached to the film substrate 26 with an adhesive layer 31 .

Next, a patterning process is performed on the foil. Patterning is a processing method for forming the conductive portion 32 by removing unnecessary portions of the foil on the adhesive layer 31 by performing photolithography and optical mask processes. Processing of the heater wire portions 51 and 55 is also possible.

A resist layer 65 is formed by applying a solder resist or the like around portions of the conductive portion 32 that are different from the extending end portions 33a and 34a.
Thus, the heater film 25 comprising the film substrate 26, the adhesive layer 31, the conductive portion 32 and the resist layer 65 is produced.

The bonding of the heater film 25 to the cover base material 23 is performed, for example, as follows. The heater film 25 is formed into a shape corresponding to the shape of the front surface of the cover base material 23 . As shown in FIG. 2, a binder layer 67 is attached to the rear surface of the heater film 25 . The binder layer 67 is made of a resin material that can be bonded to the cover base material 23, such as PMMA (polymethyl methacrylate) resin, ABS resin, or the like.

The heater film 25 with the binder layer 67 attached is placed in the mold as an insert. A molten resin material is filled behind the binder layer 67 in the mold, and the cover base material 23 is insert-molded. During this molding, heat is transferred from the molten resin material to the binder layer 67, and pressure is applied to the binder layer 67, so that the binder layer 67 exerts adhesive force. Adhesion between the cover base material 23 and the heater film 25 is enhanced by the binder layer 67 .

<Protective part 70>
The protective portion 70 includes a resin sheet 71 and an adhesive layer 72 , has a sheet shape, and is disposed forward of the film substrate 26 . The protective portion 70 plays a role of protecting the heater film 25, especially the conductive portion 32 from the impact when the cover main body portion 21 is impacted from the front by flying stones or the like.

The resin sheet 71 is made of a transparent resin material that transmits millimeter waves. In this embodiment, the resin sheet 71 is made of PC resin. The resin sheet 71 is formed into a shape corresponding to the shape of the front surface of the film substrate 26 .

The adhesive layer 72 is made of OCA, like the adhesive layer 31 described above. The adhesive layer 72 adheres the resin sheet 71 to the front surface of the film substrate 26 in close contact.
The front surface of the resin sheet 71 constitutes the design surface 22 of the millimeter wave transmission cover 20 .

The millimeter wave transmission cover 20 has a mounting portion (not shown) in addition to the cover body portion 21, and is mounted to the front grille 11 or the vehicle body at this mounting portion.
As shown in FIG. 10, a connector 83 of the device 82 for power supply is further coupled to the socket portion 81 . This connection electrically connects the positive terminal portion 33 and the negative terminal portion 34 to the device 82 via the connector pins.

Next, the operation of this embodiment configured as described above will be described. In addition, effects caused by the action will also be described.
When millimeter waves are transmitted from the millimeter wave radar device 13 shown in FIG. The transmitted millimeter waves are reflected by objects in front of the vehicle, including preceding vehicles and pedestrians, and then transmit through the cover main body 21 again and are received by the millimeter wave radar device 13 . The millimeter wave radar device 13 recognizes an object based on the transmitted and received millimeter waves, and detects the distance between the vehicle 10 and the same object, the relative speed and the like.

<Improvement of millimeter wave permeability>
(1-1) As shown in FIG. 3, in the plurality of heater wire portions 51 and 55, the interval between adjacent linear portions 52 and 56 is set to about 4 mm. Therefore, millimeter waves can easily pass between the adjacent linear portions 52 and 56 . The straight portions 52 and 56 are less likely to interfere with transmission of millimeter waves.

(1-2) If the heater wire portions 51 and 55 are thick, millimeter waves are reflected by the heater wire portions 51 and 55 and attenuated. In this regard, in this embodiment, the line width of each heater wire portion 51, 55 is set to about 10 μm. Therefore, compared to Patent Document 1, in which the line width of the heater wire portion is 50 μm to 70 μm, the reflection of the millimeter wave at the heater wire portions 51 and 55 is suppressed, and the millimeter wave is easily transmitted. In this respect as well, the heater wire portions 51 and 55 are less likely to interfere with transmission of millimeter waves.

(1-3) The first positive electrode portion 41, the first negative electrode portion 42, and the second electrode portion 45 are positioned outside the millimeter wave transmission region Z1. Therefore, although the line widths of the first positive electrode portion 41, the first negative electrode portion 42, and the second electrode portion 45 are larger than the line widths of the heater wire portions 51 and 55, they are less likely to interfere with the transmission of millimeter waves. .

According to the above (1-1) to (1-3), in the present embodiment, it is possible to suppress the decrease in millimeter wave transmittance due to the addition of the heater film 25 .
Here, when ice and snow adhere to the design surface 22 of the cover main body 21 shown in FIG. In this regard, in this embodiment, power is supplied to the conductive portion 32 from the device 82 shown in FIG.

In the conductive portion 32 shown in FIG. 3 , the current is connected to the positive terminal portion 33 , the first positive electrode portion 41 , the first positive electrode portion 41 among the plurality of heater wire portions 51 and 55 and the right side of the main body portion 27 . and the second electrode portion 45 in that order. In addition, the current flows through the second electrode portion 45, the heater wire portions 51 and 55 connected to the first negative electrode portion 42 and positioned on the left side of the main body portion 27, the first negative electrode portion 42, and the negative terminal portion 34 in that order.

Each heater wire part 51 and 55 heat|fever-generates by electric current flowing. Part of the heat generated by the heater wire portions 51 and 55 is transmitted to the design surface 22 via the adhesive layer 31, the film substrate 26 and the protective portion 70 in FIG. This heat melts ice and snow adhering to the design surface 22 . Attenuation of millimeter waves due to ice and snow can be suppressed, and deterioration in detection performance of the millimeter wave radar device 13 due to adhesion of ice and snow can be suppressed.

<Improved uniformity of heat generation distribution>
(2-1) As shown in FIG. 3, the first electrode portion 40 and the second electrode portion 45 are formed behind the edge portion 28 of the main body portion 27 and vertically opposed to each other. there is The right end portions of the first electrode portion 40 and the second electrode portion 45 are located near the right end portion of the body portion 27 . The left end portions of the first electrode portion 40 and the second electrode portion 45 are located near the left end portion of the body portion 27 . Furthermore, each of the plurality of heater wire portions 51 and 55 is formed between the first electrode portion 40 and the second electrode portion 45, and is connected to the first electrode portion 40 at the first end portions 53 and 58, It is connected to the second electrode portion 45 at the second ends 54 and 62 . Thus, the plurality of heater wire portions 51 and 55 are formed over a wide area of the film substrate 26 . Therefore, a wide area of the heater film 25 can be heated.

(2-2) Further, since the plurality of heater wire portions 51 and 55 are connected in parallel to the first electrode portion 40 and the second electrode portion 45, the heater wire portions 51 and 55 are connected in parallel. A voltage is applied. Therefore, each heater wire part 51 and 55 can be made to generate heat uniformly.

(2-3) Furthermore, since the actual line width and the substantial line width of each of the first electrode portion 40 and the second electrode portion 45 are larger than the line widths of the heater wire portions 51 and 55, Each resistance of the first electrode portion 40 and the second electrode portion 45 becomes smaller than the resistance of the heater wire portions 51 and 55 . Accordingly, even if the first electrode portion 40 and the second electrode portion 45 generate heat, the heater wire portions 51 and 55 do not generate heat as much. Therefore, it becomes easier to cause the heater film 25 to generate heat with a uniform heat generation distribution by the heater wire portions 51 and 55 .

(2-4) In the present embodiment, the adjacent linear portions 52 and 56 extend in the opposite direction while being parallel to each other and separated from each other in the intersecting direction. The interval between adjacent linear portions 52 and 56 becomes uniform in the facing direction. Therefore, heat can be generated with a uniform heat generation distribution in the facing direction between the adjacent linear portions 52 and 56, compared to the case where the intervals are different in the facing direction.

(2-5) In this embodiment, the straight portions 52 and 56 are formed at regular intervals in the cross direction. Therefore, the interval between the adjacent linear portions 52 and 56 becomes uniform in the cross direction. Therefore, it becomes easier to heat the heater film 25 with a uniform heat generation distribution in the cross direction, as compared with the case where the intervals are different in the cross direction.

(2-6) The first electrode portion 40 and the second electrode portion 45 are curved so as to bulge away from each other. Therefore, among the plurality of linear portions 52 and 56, the one located in the central portion in the intersecting direction is the longest. The lengths of the straight portions 52 and 56 become shorter as they move away from the central portion in the cross direction. As the length becomes shorter, the amount of heat generated by the straight portions 52 and 56 becomes smaller. The heat generation has a distribution in which the amount of heat generation is large in the central portion in the cross direction, and the amount of heat generation decreases as the distance from the center portion in the cross direction increases.

In this regard, in the present embodiment, the heater wire portions 55 positioned on both sides in the cross direction are composed of the linear portion 56 , the first extension portion 57 and the second extension portion 61 . The heater wire portions 55 on the both sides are arranged in the first extension portion 57 and the second extension portion 61 more than the case where the heater wire portions 55 are formed only by the straight portion 56, that is, the case where the whole extends linearly in the facing direction. minutes longer.

By increasing the length as described above, the amount of heat generated by the heater wire portion 55 is increased. Accordingly, variations in heat generation distribution in the cross direction can be reduced.
Further, in the present embodiment, the total length of the heater wire portion 55 is made close to the length of the longest portion located in the central portion in the cross direction. Therefore, the variation in heat generation distribution can be further reduced.

In particular, as described above, the linear portion 56 of the heater wire portion 55 becomes shorter as it is farther from the central portion in the cross direction. However, among the heater wire portions 55 , the first extension portion 57 and the second extension portion 61 are longer as the heater wire portion 55 is farther from the central portion in the cross direction. Therefore, the total length of each heater wire portion 55 can be brought close to the length of the longest heater wire portion 51 .

(2-7) In the right half of the body portion 27, current can flow from the first electrode portion 40 toward the second electrode portion 45 by the heater wire portions 51 and 55. FIG. In the left half of the body portion 27 , current can be caused to flow from the second electrode portion 45 toward the first electrode portion 40 by the heater wire portions 51 and 55 .

Therefore, the electric current can be made to flow evenly through the entirety of the plurality of heater wire portions 51 and 55 . The heater film 25 can generate heat with a more uniform heat distribution.
By the way, when visible light is irradiated from the front of the vehicle 10 to the millimeter wave transmission cover 20 shown in FIG. Visible light passes through the body portion 27 of the film substrate 26 . Visible light irradiated to a portion where the first electrode portion 40, the second electrode portion 45 and the heater wire portions 51 and 55 are not formed is transmitted. The visible light irradiated to the first electrode portion 40, the second electrode portion 45 and the heater wire portions 51 and 55 is reflected.

<Improved Appearance of Millimeter Wave Transmission Cover 20>
(3-1) As described in (2-2) above, the plurality of heater wire portions 51 and 55 are connected in parallel to the first electrode portion 40 and the second electrode portion 45 (see FIG. 3). . Therefore, the line width of each heater wire portion 51, 55 can be made smaller than when the heater wire portions 51, 55 are connected in series to the first electrode portion 40 and the second electrode portion 45. . Also, by increasing the number of heater wire portions 51 and 55, the line width of each heater wire portion 51 and 55 can be reduced.

As the line width of the heater wire portions 51 and 55 becomes smaller, the heater wire portions 51 and 55 become less visible. Therefore, the appearance of the heater film 25 and the millimeter wave transmission cover 20 can be improved.

(3-2) As shown in FIG. 3, the first positive electrode portion 41, the first negative electrode portion 42, and the second electrode portion 45 are formed on the edge portion 28 of the body portion 27. It is less noticeable than when formed radially inward of 28 . Therefore, the appearance of the millimeter wave transmission cover 20 is further improved.

(3-3) In the present embodiment, as shown in FIGS. 11 to 13, slits 43 extending in the cross direction along the edge 28 are provided in each of the first electrode portion 40 and the second electrode portion 45. 46 is formed. The first electrode portion 40 and the second electrode portion 45 are less conspicuous than when the slits 43 and 46 are not formed. Therefore, in this respect as well, the appearance of the millimeter wave transmission cover 20 is further improved.

(3-4) As shown in FIG. 3, the adjacent linear portions 52 and 56 extend in the opposite direction while being spaced parallel to each other in the intersecting direction. The interval between adjacent linear portions 52 and 56 becomes uniform in the facing direction. Therefore, the linear portions 52 and 56 are less visible than when the intervals are different in the facing direction. Therefore, in this respect as well, the appearance of the millimeter wave transmission cover 20 is improved.

(3-5) As shown in FIG. 3, a plurality of linear portions 52 and 56 are formed at regular intervals in the cross direction. Therefore, the plurality of straight portions 52 and 56 are evenly arranged in the cross direction, and the straight portions 52 and 56 are less visible than when the intervals between the adjacent straight portions 52 and 56 are different in the cross direction. Become. In this respect as well, the appearance of the millimeter wave transmission cover 20 is improved.

(3-6) As shown in FIG. 3, the heater wire portions 55 located on both sides in the cross direction are composed of a linear portion 56, a first extension portion 57 and a second extension portion 61. As shown in FIG. The first extension portion 57 extends from the lower end portion of the straight portion 56 toward the first electrode portion 40 . The second extension portion 61 extends from the upper end portion of the straight portion 56 toward the second electrode portion 45 .

Therefore, the first electrode portion 40 is shortened due to the formation of the first extension portion 57, so that the first electrode portion 40 is less conspicuous, and the appearance is further improved. In addition, the second electrode portion 45 is shortened due to the formation of the second extension portion 61, which makes the second electrode portion 45 inconspicuous, thereby further improving the appearance.

According to this embodiment, the following effects are obtained in addition to the above.
(4-1) If the slit 43 is not formed in the first electrode portion 40 and the slit 46 is not formed in the second electrode portion 45, the following phenomenon may occur. That is, the difference in rigidity between a portion of the heater film 25 where the first electrode portion 40 and the second electrode portion 45 are formed and a portion where the first electrode portion 40 and the second electrode portion 45 are not formed increases. The portions of the heater film 25 where the first electrode portion 40 and the second electrode portion 45 are formed are less likely to be bent and deformed.

In this regard, in the present embodiment, as shown in FIGS. 11 to 13, the first electrode portion 40 is formed with a slit 43 extending in the cross direction along the lower portion 28L, and the second electrode portion 45 is A slit 46 extending in the cross direction is formed along the upper portion 28U.

Therefore, in the heater film 25, the portions where the first electrode portion 40 and the second electrode portion 45 are formed, and the portions where the first electrode portion 40 and the second electrode portion 45 are not formed, particularly the first electrode portion 40 and the second electrode portion 45 and the portions around them. difference in rigidity becomes smaller.

Therefore, it is possible to easily bend the portion of the heater film 25 where the first electrode portion 40 and the second electrode portion 45 are formed.
(4-2) If the heater wire portions 51 and 55 are connected in series to the first positive electrode portion 41 and the first negative electrode portion 42, the heater wire portions 51 and 55 may have the following configuration. That is, the heater wire portions 51 and 55 are configured by a plurality of straight portions and arc-shaped connecting portions that connect the ends of the adjacent straight portions.

However, in this case, the connecting portion has to be formed at a location spaced radially inward from the edge portion 28 of the cover main body portion 21, and the area capable of generating heat is correspondingly reduced.
In this regard, in this embodiment, as shown in FIG. 3, the first positive electrode portion 41, the first negative electrode portion 42, and the second electrode portion 45 are formed behind the edge portion 28 of the body portion 27. As shown in FIG. The straight portion 52 of the heater wire portion 51 is extended to the lower portion 28L and connected to the first electrode portion 40, and is extended to the upper portion 28U and connected to the second electrode portion 45. As shown in FIG.

A straight portion 56 of the heater wire portion 55 extends to the lower portion 28L and is connected to the first electrode portion 40 via a first extension portion 57 extending along the lower portion 28L. The straight portion 56 extends to the upper portion 28U and is connected to the second electrode portion 45 via a second extension portion 61 extending along the upper portion 28U.

Since the linear portions 52 and 56 extend to the lower portion 28L and the upper portion 28U in this manner, the area where heat can be generated is larger than in the case where they are connected in series as described above.
(4-3) As shown in FIGS. 10, 13 and 14, in the present embodiment, the positive terminal portion 33 and the negative terminal portion 34 are formed in a net shape.

Therefore, the positive terminal portion 33 and the negative terminal portion 34 are likely to bend or deform when receiving force from the outside. Therefore, it is possible to suppress cracking or the like of the positive terminal portion 33 and the negative terminal portion 34 by receiving the force.

It should be noted that the above-described embodiment can also be implemented as a modified example in which this is changed as follows. The above embodiments and the following modifications can be combined with each other within a technically consistent range.

<Regarding the shape of the cover main body 21>
- In FIG. 1, the shape of the cover main body 21 viewed from the front may be changed to a shape different from that of the above-described embodiment, such as a circular shape or a polygonal shape.

<Layer Structure of Heater Film 25>
- In FIG. 2, the adhesive layer 31 may be formed on the front surface of the film substrate 26 and the conductive portion 32 may be formed on the front surface of the adhesive layer 31 . In this case, the film substrate 26 may be made of a non-transparent resin material.

<Regarding the position of the connection part 29>
3 and 10, the connecting portion 29 may extend from the edge portion 28 of the main body portion 27, and may extend from a location different from the above-described embodiment, such as an upper portion, a side portion, or a lower portion.

When the connecting portion 29 extends downward from the central portion 28C, the first positive electrode portion 41 does not need the narrow portion 41a, and the first negative electrode portion 42 does not need the narrow portion 42a. The first positive electrode portion 41 and the first negative electrode portion 42 are not adjacent to each other in the radial direction, but are adjacent only in the direction (circumferential direction) along the lower portion 28L.

<Regarding the first electrode portion 40 and the second electrode portion 45>
- In FIG. 3, the first electrode portion 40 and the second electrode portion 45 may be arranged facing each other in a direction different from the vertical direction on condition that they are outside the transmissive region Z1. For example, the first electrode portion 40 and the second electrode portion 45 may be arranged facing each other in the left-right direction, or may be arranged facing each other in a direction along a line that obliquely intersects a vertical line or a horizontal line. may

In these cases, the directions in which the linear portions 52 and 56 of the heater wire portions 51 and 55 extend may also be changed to the facing directions.
Contrary to the above embodiment, the right side portion of the first electrode portion 40 may be configured by the first negative electrode portion 42 and the left side portion may be configured by the first positive electrode portion 41 . Accordingly, the negative terminal portion 34 is provided on the right side of the connecting portion 29 and the positive terminal portion 33 is provided on the left side of the connecting portion 29 .

In this case, the direction of current flow is opposite to that in the above embodiment. That is, current flows from the first electrode portion 40 to the second electrode portion 45 in the left half of the heater film 25, and current flows from the second electrode portion 45 to the first electrode portion 40 in the right half of the heater film 25. flow toward

- In FIG.12 and FIG.13, the slit 43 in at least one of the 1st positive electrode part 41 and the 1st negative electrode part 42 may be abbreviate|omitted.
Similarly, in FIG. 11, the slit 46 of the second electrode portion 45 may be omitted.

- A portion of the edge portion 28 of the main body portion 27 may be formed in a straight line, and a portion of the edge portion 28 facing the portion may be curved so as to bulge away from the same portion.
In this case, the shapes of the first electrode portion 40 and the second electrode portion 45 are also changed. That is, one of the first electrode portion 40 and the second electrode portion 45 is formed in a straight line, and the other is formed in a curved shape so as to bulge away from the one.

<Regarding heater wire portions 51 and 55>
- The linear portions 52, 56 of the heater wire portions 51, 55 may extend in a direction inclined with respect to the facing direction.

- The number of heater wire portions 55 for each side portion may be changed to a number different from that in the above embodiment. The smallest number is 0. With this change, the total number of heater wire portions 51 and 55 changes.
When the number of heater wire portions 55 is changed under the condition that the total number of heater wire portions 51 and 55 remains unchanged, the changed heater wire portion 55 is replaced with the heater wire portion 51 .

- The length of the heater wire part 55 may be lengthened by the method different from the said embodiment.
4 and 5 , the linear portion 56 of the heater wire portion 55 oscillates in both directions of the intersecting direction and, in other words, meanders in a non-linear manner extending in the opposite direction. 85 has been changed.

8 and 9, the linear portion 56 of the heater wire portion 55 is changed to a so-called zigzag non-linear portion 86 that is repeatedly bent in the cross direction.

In any of the modifications described above, the nonlinear portions 85 and 86 are longer than the linear portion 56 .
As described above, when the non-linear portions 85 and 86 are set in the heater wire portion 55, it is desirable to design them so that they have only a slight effect on the millimeter wave permeability and appearance.

In the above design, the length of the heater wire portion 55 having the non-linear portions 85 and 86 is the longest of the plurality of heater wire portions 51, i. should be designed to approach

Since the heater wire portion 55 has the non-linear portions 85 and 86 as described above, when the millimeter wave transmission cover 20 is used, an outward force is applied to the cover body portion 21 from the outside in the facing direction. In this case, the following effects can be expected. That is, the nonlinear portions 85 and 86 are pulled and deformed by the above force. However, the non-linear portions 85 and 86 are less likely to be fully stretched, and excessive tension applied to the non-linear portions 85 and 86 can be suppressed.

- In FIG.8 and FIG.9, at least one of the 1st extension part 57 and the 2nd extension part 61 may replace with circular arc shape, and may be formed in linear shape.
- At least one of the first extension portion 57 and the second extension portion 61 may also be formed in a meandering or zigzag shape like the non-linear portions 85 and 86 described above.

As for the heater wire portion 51 , the straight portion 52 may be changed to a meandering or zigzag non-linear portion like the non-linear portions 85 and 86 of the heater wire portion 55 .
- For uniform heat generation distribution, the interval between the straight portions 52 and 56 may be maximized at the central portion in the intersecting direction, and may be reduced with increasing distance from the central portion.

Further, the interval may be constant in the same direction at the intermediate portion in the cross direction, and the interval may be smaller at the side portions in the cross direction than at the intermediate portion.
<Overall Conductive Part 32>
- The conductive part 32 may be formed by patterning a metal film such as copper or silver formed by plating by etching.

<Layer Structure of Millimeter Wave Transmission Cover 20>
The millimeter wave transmission cover 20 has a layered structure in which a plurality of layers including the heater film 25 are laminated in the front-rear direction. The configuration of layers in this layer structure may be changed, for example, as follows.

- When the film base material 26 has sufficient thickness to protect the conductive part 32 and the like, the protective part 70 can be omitted.
• The resist layer 65 may be formed by a binder layer 67 if the resist layer 65 is not required. In other words, the portion illustrated with the resist layer 65 and the binder layer 67 in FIG. 2 may be configured with the binder layer 67 alone.

The binder layer 67 is provided as an adhesive layer for adhering the heater film 25 to the cover base material 23 when resin-molding the cover base material 23 on the rear side of the heater film 25 . A similar adhesion layer can also be formed by the above OCA. In this case, the resist layer 65 and binder layer 67 may be replaced with OCA.

- The number of layers different from the heater film 25 in the layer structure may be changed to a different number from the above embodiment.
• New layers may be added for additional functionality.

If a layer is added on the front side of the heater film 25, the layer is made of a transparent resin material so that the heater film 25 can be seen through the same layer from the outside of the vehicle 10.例文帳に追加

If a layer is added behind heater film 25, that layer may be transparent or opaque.
<Others>
- The millimeter wave transmission cover 20 can be embodied as an emblem, an ornament, a mark, or the like of the vehicle 10 .

- The electromagnetic wave permeable cover can be applied to any vehicle equipped with a device for transmitting and receiving electromagnetic waves for detecting objects outside the vehicle. In this case, electromagnetic waves transmitted and received by the device include electromagnetic waves such as near-infrared rays in addition to millimeter waves.

A device for transmitting and receiving electromagnetic waves for detecting an object outside the vehicle may be a device for rear monitoring, front side monitoring, or rear side monitoring, in addition to forward monitoring. In this case, the electromagnetic wave transparent cover is arranged in front of the device in the transmission direction of the electromagnetic waves.

- The electromagnetic wave permeable cover can also be applied when a device that transmits and receives electromagnetic waves is mounted on a vehicle other than a vehicle, such as an aircraft or a ship.

10... vehicle (vehicle)
13 ... millimeter wave radar device (device)
20 ... millimeter wave transmission cover (electromagnetic wave transmission cover)
DESCRIPTION OF SYMBOLS 25... Heater film 32... Conductive part 33... Plus terminal part 34... Minus terminal part 40... First electrode part 41... First plus electrode part 42... First minus electrode part 43, 46... Slit 45... Second electrode part 51 , 55... Heater wire part 52, 56... Straight part 53, 58... First end part 54, 62... Second end part 57... First extension part 61... Second extension part 82... Device Z1... Transmission region

Claims (7)

Applied to a vehicle equipped with a device for transmitting and receiving electromagnetic waves, disposed in front of the device in the transmission direction of the electromagnetic wave, and having a layer structure in which a plurality of layers are laminated in the transmission direction, An electromagnetic wave transmission cover in which one of the layers of is made of a heater film,
The heater film has a conductive portion made of a conductive material,
The conductive portion includes a plurality of heater wire portions, a first electrode portion and a second electrode portion,
The first electrode portion and the second electrode portion are positioned outside the transmission region of the electromagnetic wave and face each other with the transmission region interposed therebetween,
When the direction in which the first electrode portion and the second electrode portion face each other is defined as the facing direction, and the direction that intersects the facing direction is defined as the crossing direction, the first electrode portion and the second electrode portion are the crossing direction. extending in the direction of
each of the plurality of heater wire portions has a first end and a second end;
The first end of each heater wire portion is connected to the first electrode portion, the second end portion of each heater wire portion is connected to the second electrode portion,
Further, the electromagnetic wave transmitting cover, wherein the first electrode portion and the second electrode portion have a line width larger than that of the heater wire portion. 2. The electromagnetic wave permeable cover according to claim 1, wherein a slit extending in the cross direction is formed in each of the first electrode portion and the second electrode portion. Of the plurality of heater wire portions, each of the plurality of heater wire portions positioned at least in an intermediate portion in the intersecting direction is composed of a linear portion extending linearly in the facing direction as a whole,
3. The electromagnetic wave according to claim 1 or 2, wherein the straight portions of the plurality of heater wire portions positioned at least in intermediate portions in the cross direction extend in the opposite direction while being spaced parallel to each other in the cross direction. transparent cover. 4. The electromagnetic wave permeable cover according to claim 3, wherein in the plurality of heater wire portions positioned at least in the middle portion in the cross direction, the straight portions are formed at regular intervals in the cross direction. one of the first electrode portion and the second electrode portion is curved so as to swell away from the other, and the other is curved so as to swell away from the one;
5. The heater wire part according to claim 3, wherein, among the plurality of heater wire parts, the heater wire parts located on both sides in the intersecting direction are formed to be longer than in the case where the whole extends linearly in the opposing direction. Electromagnetic transmission cover. The heater wire portions located on both sides in the cross direction are
a linear portion extending linearly in the facing direction outside the first electrode portion and the second electrode portion in the intersecting direction;
a first extension portion extending from one end of the straight portion toward the first electrode portion and having the first end;
and a second extension portion extending from the other end of the straight portion toward the second electrode portion and having the second end, and the first extension portion is configured to extend from the first end to the second electrode portion. 6. The electromagnetic wave permeable cover according to claim 5, wherein the cover is connected to one electrode portion, and the second extension portion is connected to the second electrode portion at the second end portion. The conductive part further comprises a positive terminal part and a negative terminal part to which a device for power supply is connected,
The first electrode portion includes a first positive electrode portion connected to the positive terminal portion, and a first negative electrode portion separated from the first positive electrode portion and connected to the negative terminal portion. Consists of
The first positive electrode portion and the first negative electrode portion are adjacent to each other while being spaced apart at least in the cross direction,
The second electrode portion faces the first positive electrode portion and the first negative electrode portion as a relay electrode portion between the first positive electrode portion and the first negative electrode portion,
The first end of some of the heater wire portions is connected to the first positive electrode portion, the second end of the some of the heater wire portions is connected to the second electrode portion, and the remainder of the heater wire portion is connected to the second electrode portion. The first end of the heater wire portion is connected to the first negative electrode portion, and the second end of the remaining heater wire portion is connected to the second electrode portion. The electromagnetic wave transmission cover according to any one of .

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