JP6079547B2 - Planar heating element for window and window for vehicle - Google Patents

Description

  The present invention relates to a planar heating element for a window and a vehicle window.

  Conventionally, a defogger for removing fogging and freezing of the window is attached to the surface of the window of the automobile. In particular, as a defogger attached to the surface of a rear window of an automobile, a hot wire defogger in which a conductive wire as a heating element is formed is used. There is also known an electrically heated window glass in which an electrode wire is embedded in a window glass of a vehicle such as an automobile, and the electrode wire is heated by passing an electric current.

  For example, Patent Document 1 describes a rear window glass for an automobile in which the specific resistance of a transparent conductive thin film is changed depending on the location in order to preferentially defrost or thaw a portion where the field of view is to be secured immediately (for example, (See Patent Document 1, columns 3, 6 and 7).

  In FIG. 21, the typical top view of the rear window glass for motor vehicles described in the conventional patent document 1 is shown. The rear window glass for automobiles described in Patent Document 1 has a structure in which electrodes 104 for energizing the transparent conductive thin film 100 are provided on both sides of the transparent conductive thin film 100 as a heating element. . Here, the upper portion 101 and the lower portion 103 of the transparent conductive thin film 100 are portions having a low specific resistance, and the intermediate portion 102 between the upper portion 101 and the lower portion 103 is a portion having a high specific resistance. It has become. When the transparent conductive thin film 100 is energized after spraying steam on the rear window glass for an automobile described in Patent Document 1 having such a structure, the intermediate portion 102 having a high specific resistance of the transparent conductive thin film 100 is obtained. It is said that fogging has been removed in a short time as the center (see, for example, column 7 of Patent Document 1).

  The rear window glass for automobiles described in Patent Document 1 is manufactured as follows (see, for example, columns 6 and 7 of Patent Document 1). First, the rear window glass-shaped transparent substrate for automobiles was thoroughly washed with an organic solvent and pure water, and then silver paste containing glass frit was screen-printed as an electrode 104 on the upper and lower sides of the transparent substrate, respectively, and dried. I will burn it later.

  Next, the entire transparent substrate is placed in a sputtering vacuum chamber, and the transparent conductive thin film 100 is formed on the surface of the transparent substrate by sputtering. Next, laser beam heating is performed such that the heating temperature of the intermediate portion 102 of the transparent conductive thin film 100 is lower than the heating temperature of the upper portion 101 and the lower portion 103. Thereby, the rear window glass for automobiles described in Patent Document 1 in which the specific resistance of the intermediate portion 102 of the transparent conductive thin film 100 is higher than the specific resistance of the upper side portion 101 and the lower side portion 103 is produced.

Japanese Utility Model Publication No. 4-50203

  As described above, the automotive rear window glass disclosed in Patent Document 1 changes the heating temperature of the transparent conductive thin film 100 by laser beam irradiation, thereby increasing the specific resistance region (intermediate portion 102) and the specific resistance. Low regions (upper side portion 101 and lower side portion 103) are separately formed.

  However, when a resin substrate such as polyacrylonitrile or polycarbonate is used as the transparent substrate of the rear window glass for automobiles described in Patent Document 1, the heating temperature of the transparent conductive thin film 100 by laser beam irradiation is 130 ° C. or higher. When such a high temperature is used, the transparent substrate becomes soft, so that there is a problem that the method described in Patent Document 1 cannot be used.

  In view of the above circumstances, even when a resin base material is used, it is desirable to provide a heating element for a window and a vehicle window that can preferentially heat a desired portion and heat the entire rear surface. Objective.

  According to the first aspect, which is an example of the present invention, a resin base material having a planar or curved surface, and a heating element made of a conductive sheet provided on the resin base material, The first heat generation area, the second heat generation area, and the third heat generation area, which are spread out in a plane along the shape of the surface of the resin base material, are divided into the first heat generation area and the second heat generation area. A first connection for connecting the heat generation region in series; a second connection for connecting the second heat generation region and the third heat generation region in series; and a first connection for supplying current from an external power source. 1st heat supply area | region and the 1st electric power feeding part provided in the side facing the side provided with the 1st connection part, and the side provided with the 2nd connection part of the 3rd heat generation area And a width in a direction perpendicular to the direction in which the current flows in the second heat generation region. It is possible to provide a planar heating element for a window that is narrower than a width in a direction perpendicular to the direction in which the current in the first heat generation region flows and a width in a direction perpendicular to the direction in which the current in the third heat generation region flows. .

  According to the 2nd aspect which is another example of this invention, the vehicle window containing the planar heating element for windows of the 1st aspect of this invention can be provided.

  According to the above aspect, even when a resin base material is used, it is possible to provide a window heating element and a vehicle window that can heat a desired portion with priority and can heat the entire rear surface. it can.

FIG. 3 is a schematic plan view of the back surface of the window sheet heating element according to the first embodiment. FIG. 3 is a schematic enlarged plan view of a conductive mesh that is an example of a conductive sheet used for the heating element of the planar heating element for a window according to the first embodiment. FIG. 3 is a schematic cross-sectional view along III-III in FIG. 2. FIG. 4 is a schematic cross-sectional view along IV-IV in FIG. 2. It is typical sectional drawing along VV of FIG. It is typical sectional drawing along VI-VI of FIG. It is typical sectional drawing in alignment with VII-VII of FIG. 5 is a flowchart of an example of a method for manufacturing the planar heating element for a window according to the first embodiment. FIG. 3 is a schematic cross-sectional view illustrating a part of a heating element manufacturing step of the method for manufacturing a planar heating element for a window according to the first embodiment. It is typical sectional drawing in alignment with XX of FIG. FIG. 6 is a schematic cross-sectional view illustrating another part of the heating element manufacturing step of the method for manufacturing the planar heating element for window according to the first embodiment. It is typical sectional drawing along XII-XII of FIG. FIG. 3 is a schematic cross-sectional view illustrating a part of the heating element installation step of the method for manufacturing the planar heating element for a window according to the first embodiment. FIG. 6 is a schematic cross-sectional view illustrating another part of the heating element installation step of the method for manufacturing the planar heating element for a window according to the first embodiment. FIG. 6 is a schematic cross-sectional view illustrating another part of the heating element installation step of the method for manufacturing the planar heating element for a window according to the first embodiment. FIG. 6 is a schematic cross-sectional view illustrating another part of the heating element installation step of the method for manufacturing the planar heating element for a window according to the first embodiment. FIG. 6 is a schematic cross-sectional view illustrating another part of the heating element installation step of the method for manufacturing the planar heating element for a window according to the first embodiment. FIG. 3 is a schematic plan view illustrating the function and effect of the window heating element according to the first embodiment. FIG. 6 is a schematic plan view of the back surface of a window-shaped heating element according to the second embodiment. FIG. 6 is a schematic plan view illustrating the operation and effect of the planar heating element for a window according to the second embodiment. It is a typical top view of the rear window glass for motor vehicles described in patent documents 1 of the past.

  Hereinafter, an embodiment which is an example of the present invention will be described. Note that in the drawings used to describe the embodiments, the same reference numerals represent the same or corresponding parts.

[Embodiment 1]
<Structure of planar heating element for window>
FIG. 1 is a schematic plan view of the back surface of the window heating element according to the first embodiment which is an example of the present invention. As shown in FIG. 1, the planar heating element for a window according to the first embodiment includes a resin base material 1 made of polycarbonate and a conductive sheet provided on the back surface opposite to the surface of the resin base material 1. The heating element 2 is provided. The heating element 2 includes a first heat generation region 2a, a second heat generation region 2b, and a third heat generation region 2c that are divided from each other. The first heat generation region 2 a, the second heat generation region 2 b, and the third heat generation region 2 c each extend in a planar shape along the shape of the surface of the resin base material 1. Further, from one end of the resin base material 1 to the other end (in the present embodiment, from the left end to the right end in FIG. 1), the first heat generation region 2a, the second heat generation region 2b, and the second end Three heating regions 2c are arranged in this order at intervals. The resin substrate 1 may have either a flat surface or a curved surface.

  In addition, the heating element 2 includes a first connection portion 4a that connects the first heat generation region 2a and the second heat generation region 2b in series, and a second heat generation region 2b and a third heat generation region 2c that are connected in series. And a second connection portion 4b connected to the. Here, the first connecting portion 4a electrically connects the lower end of the first heat generating region 2a and the lower end of the second heat generating region 2b. The second connection portion 4b electrically connects the upper end of the second heat generating region 2b and the upper end of the third heat generating region 2c.

  Furthermore, the heating element 2 has a bowl-shaped first power feeding portion 3a electrically connected to the upper end of the first heat generation area 2a, and a bowl-shape electrically connected to the lower end of the third heat generation area 2c. 2nd electric power feeding part 3b. The first power supply unit 3a and the second power supply unit 3b supply current from the external power source (not shown) to the first heat generation region 2a, the second heat generation region 2b, and the third heat generation region 2c. Is provided. The first power feeding unit 3a is provided on the side of the first heat generating region 2a opposite to the side on which the first connection unit 4a is provided, and the second power feeding unit 3b It is provided on the side opposite to the side where the second connection portion 4b of the heat generating area 2c is provided.

  That is, one end (upper end) of the direction in which the current in the first heat generating region 2a flows (hereinafter referred to as “current direction”) is orthogonal to the direction in which the current in the first heat generating region 2a flows (hereinafter, “ The first power feeding portion 3a is provided so as to extend in the “current orthogonal direction”. In addition, a first connection portion 4a is provided at the other end (lower end) in the current direction of the first heat generation region so as to extend in the current orthogonal direction of the first heat generation region 2a. The first power supply portion 3a and the first connection portion 4a face each other across the first heat generation region 2a in the current direction of the first heat generation region 2a.

  Moreover, the 1st connection part 4a is provided in the one end (lower end) of the current direction of the 2nd heat_generation | fever area | region 2b so that it may extend in the electric current orthogonal direction of the 2nd heat_generation | fever area | region 2b. In addition, a second connection portion 4b is provided at the other end (upper end) in the current direction of the second heat generation region 2b so as to extend in the current orthogonal direction of the second heat generation region 2b. The first connection portion 4a and the second connection portion 4b face each other across the second heat generation region 2b in the current direction of the second heat generation region 2b.

  Furthermore, a second connection portion 4b is provided at one end (upper end) in the current direction of the third heat generating region 2c so as to extend in the current orthogonal direction of the third heat generating region 2c. In addition, a second power feeding portion 3b is provided at the other end (lower end) in the current direction of the third heat generating region 2c so as to extend in the current orthogonal direction of the third heat generating region 2c. The second connecting portion 4b and the second power feeding portion 3b face each other across the third heat generating region 2c in the current direction of the third heat generating region 2c.

  In the planar heating element for a window according to the first embodiment, current can be supplied from either the first power feeding unit 3a or the second power feeding unit 3b. When current is supplied from the first power supply unit 3a or the second power supply unit 3b, the first heat generation region 2a, the second heat generation region 2b, and the third of the heat generating element 2 made of a conductive sheet are energized. The heat generation regions 2c generate heat due to their own electrical resistance, and heat generated in the first heat generation region 2a, the second heat generation region 2b, and the third heat generation region 2c is conducted to the surface of the resin base material 1, The surface of the window sheet heating element is heated.

  For example, when a current is supplied from the first power supply unit 3a, the current passes through the first heat generation region 2a from the first power supply unit 3a and the first connection on the lower side of the first heat generation region 2a. Flow from the first connection portion 4a through the second heat generation region 2b to the second connection portion 4b above the second heat generation region 2b, and from the second connection portion 4b. It flows through the third heat generating region 2c to the second power feeding unit 3b below the third heat generating region 2c.

  In addition, for example, when a current is supplied from the second power supply unit 3b, the current passes through the third heat generation region 2c from the second power supply unit 3b, and the second current on the upper side of the third heat generation region 2c. It flows to the connection portion 4b, and then flows from the second connection portion 4b to the first connection portion 4a below the second heat generation region 2b through the second heat generation region 2b, and then the first connection portion. From 4a, it flows through the first heat generation area 2a to the first power supply section 3a on the upper side of the first heat generation area 2a.

  Here, in the planar heating element for a window according to the first embodiment, the width b in the current orthogonal direction of the second heat generation region 2b is equal to the width a in the current orthogonal direction of the first heat generation region 2a and the third heat generation region. It is narrower than the width c in the current orthogonal direction of 2c.

  FIG. 2 is a schematic enlarged plan view of a conductive mesh which is an example of a conductive sheet used for the heating element 2 of the planar heating element for a window according to the first embodiment. The conductive mesh has a plurality of first conductive lines 21 and a plurality of second conductive lines 22. The first conductive lines 21 extend along the first direction 31 with a space therebetween, and the second conductive lines 22 are spaced apart from each other in a direction different from the first direction 31. It extends along a second direction 32.

  In addition, the first conductive line 21 and the second conductive line 22 intersect so that a plurality of openings 24 are formed. In the first embodiment, one first conductive line 21 is fixed to each of a plurality of second conductive lines 22 at intersections 23, and one second conductive line 22 includes a plurality of second conductive lines 22. Each of the first conductive lines 21 is fixed at the intersection 23. An opening 24 is an area of a space surrounded by two adjacent first conductive lines 21 and two adjacent second conductive lines 22.

  The aperture ratio of the conductive mesh is not particularly limited, but is preferably 70% or more. When the opening ratio of the conductive mesh is set to 70% or more, the first conductive wire 21 and the second conductive wire 21 when the planar heating element for window of the first embodiment is viewed from the surface side of the resin base material 1 are used. Since the visibility of the conductive wire 22 can be lowered, the transparency of the window heating element for window according to the first embodiment (the property that at least part of visible light (wavelength 360 nm to 830 nm) is transmitted: transmission of visible light) The higher the rate, the higher the transparency). Therefore, in this case, the planar heating element for windows of Embodiment 1 can be suitably used as a vehicle window with a defogger function that requires transparency, such as a rear window of an automobile.

  The aperture ratio [%] of the conductive mesh can be calculated by a known formula. For example, it can be calculated by the following formula (I). In the formula (I), the mesh is the inner dimension d3 between two adjacent conductive lines, and the pitch is the distance d4 between the centers of the two adjacent conductive lines.

Opening ratio [%] of conductive mesh = 100 × {(mesh) / (pitch)} ² (I)

  FIG. 3 shows a schematic cross-sectional view along III-III in FIG. As shown in FIG. 3, the first conductive wire 21 has a first core wire 21a made of polyester and a first covering material 21b made of copper covering the outer surface of the first core wire 21a. Yes. In addition, the 1st core wire 21a and the 1st coating | covering material 21b may each be comprised only from the single layer, and may be comprised from the multiple layer. In addition, when the 1st core wire 21a and / or the 1st coating | covering material 21b are comprised from multiple layers, all the materials of each layer which comprise multiple layers may be the same, The at least 1 layer is at least May be different.

  The thickness d1 of the first conductive wire 21 shown in FIG. 2 is not particularly limited, but is preferably 0.3 mm or less, more preferably 0.2 mm or less, and further preferably 0.08 mm or less. preferable. As the thickness d1 of the first conductive line 21 is set to 0.3 mm or less, 0.2 mm or less, and 0.08 mm or less, the first conductive line 21 can be made thinner. Since the visibility of the first conductive wire 21 when the sheet heating element is viewed from the surface side of the resin base material 1 can be lowered, the transparency of the window heating element for window according to the first embodiment is improved. Can be improved. Therefore, also in this case, the planar heating element for windows of Embodiment 1 can be suitably used as a vehicle window with a defogger function that requires transparency, such as a rear window of an automobile. The thickness d1 of the first conductive line 21 is a direction orthogonal to the extending direction of the first conductive line 21 (first direction 31) on the surface of the conductive mesh, for example, as shown in FIG. Is the length of

  FIG. 4 is a schematic cross-sectional view taken along the line IV-IV in FIG. As shown in FIG. 4, the second conductive wire 22 includes a second core wire 22a made of polyester and a second covering material 22b made of copper covering the outer surface of the second core wire 22a. Yes. In addition, the 2nd core wire 22a and the 2nd coating | covering material 22b may each be comprised only from the single layer, and may be comprised from the multiple layer. In addition, when the 2nd core wire 22a and / or the 2nd coating | covering material 22b are comprised from multiple layers, the material of each layer which comprises multiple layers may be the same, and the at least 1 layer is at least May be different.

  The thickness d2 of the second conductive wire 22 shown in FIG. 2 is not particularly limited, but is preferably 0.3 mm or less, more preferably 0.2 mm or less, and further preferably 0.08 mm or less. preferable. As the thickness d2 of the second conductive wire 22 is set to 0.3 mm or less, 0.2 mm or less, and 0.08 mm or less, the second conductive wire 22 can be made thinner. Since the visibility of the second conductive wire 22 can be reduced when the planar heating element for the window is viewed from the surface side of the resin base material 1, the transparency of the planar heating element for the window of the first embodiment can be reduced. Can be improved. Therefore, also in this case, the planar heating element for windows of Embodiment 1 can be suitably used as a vehicle window with a defogger function that requires transparency, such as a rear window of an automobile. Note that the thickness d2 of the second conductive line 22 is a direction orthogonal to the extending direction of the second conductive line 22 (second direction 32) on the surface of the conductive mesh, for example, as shown in FIG. Is the length of

  FIG. 5 shows a schematic cross-sectional view along VV in FIG. 2, and FIG. 6 shows a schematic cross-sectional view along VI-VI in FIG. As shown in FIGS. 5 and 6, the first conductive wire 21 and the second conductive wire 22 are heat-sealed between the first core wire 21 a and the second core wire 22 a at the intersection 23 thereof. It is fixed by that.

  Note that the method of fixing the first conductive wire 21 and the second conductive wire 22 is not limited to the method of fixing the first core wire 21a and the second core wire 22a by thermal fusion, but the first core wire. When the first conductive wire 21 and the second conductive wire 22 are fixed by heat fusion between the first conductive wire 21a and the second core wire 22a, the first conductive wire 21 and the second conductive wire 22 are fixed. This is preferable in that the first conductive wire 21 and the second conductive wire 22 can be firmly fixed without using other materials such as an adhesive for the purpose.

  FIG. 7 shows a schematic cross-sectional view along the line VII-VII in FIG. As shown in FIG. 7, in the planar heating element for a window according to the first embodiment, the heating element 2 is embedded in the resin base material 1 inside the back surface 10 b of the resin base material 1. In addition, the heating element 2 is configured so that each surface of the first heating area 2a, the second heating area 2b, and the third heating area 2c of the heating element 2 follows the shape of the surface 10a of the resin base material 1. 7 extends in a direction perpendicular to the paper surface. Furthermore, at least a part of the surface of the first power supply unit 3a and at least a part of the surface of the second power supply unit 3b are respectively connected to the back surface of the resin base material 1 so that a power supply terminal (not shown) can be connected. 10b is exposed.

<Method for manufacturing planar heating element for window>
FIG. 8 shows a flowchart of an example of the manufacturing method of the planar heating element for window according to the first embodiment. As shown in FIG. 8, the method for manufacturing a planar heating element for a window according to the first embodiment includes a heating element manufacturing step (S10) and a heating element installation step (S20), and the heating element manufacturing step (S10). ) And the heating element installation step (S20) are performed in this order. In addition, the manufacturing method of the planar heating element for a window according to the first embodiment may include processes other than the above-described S10 and S20, and the order of the processes is not particularly limited.

≪Heat generation process≫
In the heating element manufacturing step (S10), the first heating area 2a and the second heating area are formed on the conductive member including the first heating area 2a, the second heating area 2b, and the third heating area 2c. 2b, the second connection part 4b connecting the second heat generation region 2b and the third heat generation region 2c in series, and the first connection part 4a connecting the second heat generation part 2b in series. The side opposite to the side where the first power supply part 3a provided on the side facing the side where the first connection part 4a is provided and the side where the second connection part 4b of the third heat generating region 2c is provided This is done by forming the heating element 2 by forming the second power supply portion 3b provided in the heating element 2b.

  The heating element manufacturing step (S10) can be performed, for example, as follows. First, as shown in the schematic plan view of FIG. 9, a conductive member 20 including a first heat generation region 2a, a second heat generation region 2b, and a third heat generation region 2c is prepared. For example, the conductive member 20 is formed by cutting out the above-described conductive mesh into a predetermined size and making a cut as shown in FIG. 9 to thereby form the first heat generation region 2a, the second heat generation region 2b, and the third heat generation. It can be manufactured by forming the region 2c. Here, the first heat generation region 2a and the second heat generation are set such that the width b of the second heat generation region 2b is narrower than the width a of the first heat generation region and the width c of the third heat generation region 2c. Region 2b and third heat-generating region 2c are formed. FIG. 10 shows a schematic cross-sectional view along XX in FIG.

  Next, as shown in the schematic plan view of FIG. 11, a part of the periphery of the conductive sheet 20 is folded back multiple times, and the first power feeding unit 3a, the second power feeding unit 3b, the first connection unit 4a, and The heating element 2 is manufactured by forming the second connection portions 4b. In the heat generating body 2, the first power supply section 3a, the second power supply section 3b, the first connection section 4a, and the second connection section 4b are respectively a first heat generation area 2a, a second heat generation area 2b, and It is configured by stacking the end portions of the conductive sheet 20 so as to be thicker than the third heat generating region 2c. FIG. 12 is a schematic cross-sectional view along XII-XII in FIG.

≪Heat generation process≫
In the heating element installation step (S20), the first heat generation area 2a, the second heat generation area 2b, and the third heat generation area 2b are formed on the back surface 10b that is the surface opposite to the surface 10a of the flat or curved resin base material 1. The heating element 2 is installed so that the heating area 2c extends in a plane along the shape of the surface 10a of the resin base material 1. A heating element installation process (S20) can be performed by insert molding explained in full detail below, for example.

  First, for example, as shown in the schematic cross-sectional view of FIG. 13, the heating element 2 is installed along the bottom surface 41 a of the recess of the mold 41. Here, in the heating element 2, the surfaces of the first power supply unit 3 a, the second power supply unit 3 b, the first connection unit 4 a, and the second connection unit 4 b are located on the bottom surface 41 a of the recess of the mold 41. At the same time, the first heat generation region 2a, the second heat generation region 2b, and the third heat generation region 2c are installed so as not to contact the bottom surface 41a. Further, the heating element 2 is a layer adjacent to each other of the folded layers of the conductive sheet 20 constituting the first power feeding part 3a, the second power feeding part 3b, the first connection part 4a, and the second connection part 4b. For example, the first power supply unit 3a, the second power supply unit 3b, the first connection unit 4a, and the second connection unit 4b are installed so as to be in contact with each other.

  Further, the shape of the concave portion of the mold 41 can be set as appropriate according to the shape of the planar heating element for windows of the first embodiment. For example, when the bottom surface 41a of the concave portion of the mold 41 is planar, the back surface 10b of the resin base material 1 of the planar heating element for windows of Embodiment 1 can be planar. Further, when the bottom surface 41a of the concave portion of the mold 41 has a curved shape, the back surface 10b of the resin base material 1 of the planar heating element for a window according to the first embodiment can be curved.

  Next, as shown in, for example, the schematic cross-sectional view of FIG. 14, another mold 42 having a liquid resin inlet 43 is installed on the concave side of the mold 41. Here, the shape of the surface 42a of the mold 42 on the mold 41 side can be appropriately set according to the shape of the window heating element of the first embodiment. For example, when the surface 42a of the mold 42 is planar, the surface 10a of the resin base material 1 of the planar heating element for windows of Embodiment 1 can be planar. Moreover, when the surface 42a of the metal mold 42 is curved, the surface 10a of the resin base material 1 of the planar heating element for windows of Embodiment 1 can be curved.

  Next, for example, as shown in the schematic cross-sectional view of FIG. 15, the liquid resin 1 a is injected from the injection port 43 of the mold 42 into the recess of the mold 41. The liquid resin 1a is injected so as to penetrate the entire heating element 2 and enclose the entire heating element 2. In addition, as the liquid resin 1a, the material used as the resin base material 1 when the liquid resin 1a hardens | cures is used, For example, a liquid polycarbonate can be used.

  Next, for example, as shown in the schematic cross-sectional view of FIG. 16, the liquid resin 1a injected into the concave portion of the mold 41 is cooled to cure the liquid resin 1a, thereby forming the conductive substrate 61. The conductive substrate 61 is formed by integrating the resin base material 1 formed by curing the liquid resin 1 a with the heating element 2. At this time, the first power supply portion 3a, the second power supply portion 3b, the first connection portion 4a, and the second connection are formed by the hardening of the liquid resin 1a penetrating the heat generation body 2 and enclosing the entire heat generation body 2. The layers adjacent to each other of the folded layers of the conductive sheet 20 constituting the portion 4b are fixed in contact with each other. Thereby, the 1st electric power feeding part 3a, the 2nd electric power feeding part 3b, the 1st connection part 4a, and the 2nd connection part 4b are the 1st heat_generation | fever area | region 2a, the 2nd heat_generation | fever area | region 2b, and the 3rd heat_generation | fever. Since it is formed thicker than the region 2c, it has a larger cross-sectional area than the first heat generating region 2a, the second heat generating region 2b, and the third heat generating region 2c. In addition, the hardening method of the liquid resin 1a is not limited to the method by the above-mentioned cooling, The method according to the property of the liquid resin 1a can be used suitably.

  Next, for example, as shown in the schematic cross-sectional view of FIG. 17, the conductive substrate 61 formed as described above is released from the mold 41. The method for releasing the conductive substrate 61 from the mold 41 is not particularly limited, and a conventionally known method can be appropriately used. Thereby, the planar heating element for windows of Embodiment 1 can be manufactured.

  In addition, a power supply terminal (not shown) is electrically and mechanically connected to each of the first power supply unit 3a and the second power supply unit 3b at both ends of the heating element 2 of the planar heating element for a window according to the first embodiment. You may connect. The power supply terminal is not particularly limited as long as it is a conductive material. Further, the connection method of the power supply terminal is not particularly limited, and for example, a connection method using a conductive adhesive such as solder can be used.

<Effect>
In the planar heating element for window according to the first embodiment, the width b of the second heat generating region 2b in the current orthogonal direction is equal to the width a of the first heat generating region 2a in the current orthogonal direction and the width of the third heat generating region 2c. It is narrower than the width c in the current orthogonal direction. Thereby, the electrical resistance of the 2nd heat_generation | fever area | region 2b can be made higher than the electrical resistance of the 1st heat_generation | fever area | region 2a and the 3rd heat_generation | fever area | region 2c.

  And from the 1st electric power feeding part 3a or the 2nd electric power feeding part 3b of the planar heating element for windows of Embodiment 1, it is changed to the 1st heat generating area 2a, the 2nd heat generating area 2b, and the 3rd heat generating area 2c. When a uniform current is supplied, the amount of heat generated in the second heat generating region 2b having a high electrical resistance locally increases. Therefore, as shown in the schematic plan view of FIG. Only the center of the surface of the planar heating element can be locally heated.

This is because, according to Ohm's law, the calorific value Q is represented by the product of the square of the current I and the electric resistance R (Q = I ² × R), and therefore the second heat generating region 2b having a high electric resistance. This is because the amount of heat generated can be increased locally.

  After the local heating at the center of the surface of the window sheet heating element according to the first embodiment, the window sheet heating element according to the first embodiment is generated by the heat generated in the first heating area 2a and the third heating area 2c. Surface portions other than the center of the surface are also heated.

  Moreover, in the planar heating element for windows of Embodiment 1, since the process of heating to high temperature of 130 degreeC or more using a laser beam is not required like the method of the conventional patent document 1, as a base material, The resin base material 1 can be used.

  For the reasons described above, in the first embodiment, even when the resin base material 1 is used, a planar heating element for a window that can heat a desired portion with priority and heat the entire rear surface thereof is provided. be able to.

  In addition, in the planar heating element for a window according to the first embodiment, the first power feeding unit 3a, the second power feeding unit 3b, the first connection unit 4a, and the second connection unit 4b are connected to the periphery of the conductive sheet 20. Is formed thicker than the first heat generation region 2a, the second heat generation region 2b, and the third heat generation region 2c. Therefore, in the 1st electric power feeding part 3a, the 2nd electric power feeding part 3b, the 1st connection part 4a, and the 2nd connection part 4b, the 1st heat_generation | fever area | region 2a, the 2nd heat_generation | fever area | region 2b, and the 3rd heat_generation | fever Since the current flows more easily than the region 2c, it functions as a power supply unit that supplies current to the first heat generating region 2a, the second heat generating region 2b, or the third heat generating region 2c, rather than functioning as a heating element. To do.

<Other forms>
In the above, although the case where the resin base material 1 consists of polycarbonate was demonstrated, although the resin base material 1 is not limited to a polycarbonate and resin other than a polycarbonate can also be used, it is more preferable that a polycarbonate is included. When polycarbonate is used as the resin base material 1, the transparency of the resin base material 1 can be improved and the durability of the resin base material 1 can also be improved.

  In the above description, the case where the first core wire 21a of the first conductive wire 21 of the conductive mesh and the second core wire 22a of the second conductive wire 22 are made of polyester is not limited to polyester. A material such as resin, glass, or metal can be used as appropriate. Especially, it is preferable that the 1st core wire 21a and the 2nd core wire 22a consist of the same resin. In this case, the first conductive wire 21 and the second conductive wire 22 can be firmly fixed by heat fusion between the first core wire 21a and the second core wire 22a.

  In the above, the case where the first covering material 21b of the first conductive wire 21 of the conductive mesh and the second covering material 22b of the second conductive wire 22 are made of copper has been described. For example, a conductive material such as a metal layer having a two-layer structure of copper and a metal other than copper can be appropriately used.

  In the above description, the case where the first conductive wire 21 and the second conductive wire 22 are fixed by thermal fusion between the first core wire 21a and the second core wire 22a has been described. The conductive wire 21 and the second conductive wire 22 may not be fixed. Further, for example, the first conductive wire 21 extending in the first direction 31 and the second conductive wire 22 extending in the second direction 32 different from the first direction 31 are plain weave or twill weave. The conductive mesh may be formed by weaving.

  Further, the heating element 2 may be entirely embedded in the resin base material 1 inside the back surface 10b of the resin base material 1, and the first heating element 2 is formed by folding a part of the periphery of the conductive sheet 20. If the power supply unit 3a, the second power supply unit 3b, the first connection unit 4a and the second connection unit 4b can be maintained in a state in which adjacent layers of each layer are in contact with each other, the heating element At least a part of 2 may be exposed to the outside from the back surface 10 b of the resin base material 1.

  Further, the narrow second heat generating region 2b is not limited to being arranged at the center of the surface of the window sheet heating element of the first embodiment, but can be quickly accelerated by defrosting or thawing preferentially. It can be appropriately arranged at a place where a field of view is desired.

[Embodiment 2]
In FIG. 19, the typical top view of the back surface of the planar heating element for windows of Embodiment 2 which is another example of this invention is shown. The planar heating element for windows of the second embodiment is characterized by further having a narrow region where the width of the second heat generating region 2b in the current orthogonal direction is locally narrow.

  As shown in FIG. 19, in the planar heating element for a window according to the second embodiment, the second heat generating region 2b has a locally narrow width b1 in the central region in the current direction of the second heat generating region 2b. The width b1 of the center region of the second heat generating region 2b is narrower than the width b2 of the region other than the center of the second heat generating region 2b. The width b1 and the width b2 are widths in the current orthogonal direction of the second heat generating region 2b, respectively. In addition, the relationship among the width a, the width b1, the width b2, and the width c is such that the width b1 <the width b2 <the width a and the width c.

  Thereby, also in the planar heating element for windows of the second embodiment, the electric resistance is reduced by the uniform current supplied from the first power feeding section 3a or the second power feeding section 3b as in the first embodiment. Since the amount of heat generated in the high second heat generating region 2b locally increases, only the center of the surface of the window-shaped heating element for window according to the second embodiment is locally heated as shown in the schematic plan view of FIG. can do.

  Furthermore, in the window heating element of the second embodiment, among the second heat generation area 2b, the heat generation amount of the narrow area 2b1 at the center of the second heat generation area 2b is set to a value other than that of the narrow area 2b1. The amount of heat generated in the region 2b2 can be made larger. Therefore, in the window planar heating element of the second embodiment, the locally heated region of the surface of the window planar heating element of the second embodiment can be divided into finer areas.

  After the local heating at the center of the surface of the window heat generating element for window according to the second embodiment, the window heat generating element for window according to the second embodiment is generated by the heat generation of the first heat generating area 2a and the third heat generating area 2c. Surface portions other than the center of the surface are also heated.

  Further, in the window-shaped heating element of the second embodiment, since there is no need for a step of heating to a high temperature of 130 ° C. or higher using a laser beam as in the conventional method described in Patent Literature 1, The resin substrate 1 can be used.

  For the above reasons, even in the second embodiment, even when the resin base material 1 is used, a window-like heating element and a window that can preferentially heat a desired portion and heat the entire rear surface can be used. A method for manufacturing a planar heating element can be provided.

  Since the description other than the above in Embodiment 2 is the same as that in Embodiment 1, the description thereof will not be repeated.

[Appendix]
(1) According to the first aspect which is an example of the present invention, the heat generating device includes a resin base material having a planar or curved surface and a heating element made of a conductive sheet provided on the resin base material. The body includes a first heat generation region, a second heat generation region, and a third heat generation region that are spread out in a plane along the shape of the surface of the resin base material, and the first heat generation region, To supply a current from an external power source, a first connection portion that connects the second heat generation region in series, a second connection portion that connects the second heat generation region and the third heat generation region in series, and Of the first heat generating area, the first power feeding section provided on the side facing the side where the first connecting section is provided, and the second connecting section of the third heat generating area. A second power feeding portion provided on the side opposite to the side, and in a direction orthogonal to the direction in which the current in the second heat generation region flows However, there is provided a planar heating element for a window that is narrower than a width in a direction orthogonal to the direction in which the current in the first heat generation region flows and a width in a direction orthogonal to the direction in which the current in the third heat generation region flows. be able to. According to the planar heating element for a window of the first aspect of the present invention, the electric resistance of the second heat generating region is locally increased, and a uniform current is supplied from the first power feeding unit or the second power feeding unit. In this case, since the amount of heat generated in the second heat generating region having high electric resistance can be locally increased, the surface of the window heating element for the window is locally heated, and thereafter the first heat generating region And the other part of the surface of the sheet heating element for windows can be heated by the heat generation in the third heat generating region. Moreover, according to the planar heating element for windows of the first aspect of the present invention, there is no need for a step of heating to a high temperature of 130 ° C. or higher using a laser beam as in the conventional method described in Patent Document 1. A resin base material can be used as the base material. Thereby, even when a resin base material is used, the planar heating element for windows which can heat a desired location preferentially and can heat the whole surface after that can be provided.

  (2) In the first aspect of the present invention, the first connecting portion, the second connecting portion, the first feeding portion, and the second feeding portion are respectively a first heat generation region and a second heat generation portion. It is preferable that the end portions of the conductive sheet are laminated so as to be thicker than the region and the third heat generation region. In this case, a 1st connection part, a 2nd connection part, a 1st electric power feeding part, and a 2nd electric power feeding part can be formed easily.

  (3) In the first aspect of the present invention, the first power feeding section is provided at one end in the current direction of the first heat generation region so as to extend in the current orthogonal direction of the first heat generation region. The first connecting portion is provided at the other end in the current direction of the first heat generating region so as to extend in the current orthogonal direction of the first heat generating region, and the first power feeding portion and the first connecting portion are connected to each other. The first heat generating area faces each other, and the first connecting portion is provided at one end of the second heat generating area in the current direction so as to extend in the current orthogonal direction of the second heat generating area. The second connection portion is provided at the other end in the current direction of the second heat generation region so as to extend in the current orthogonal direction of the second heat generation region, and the first connection portion and the second connection portion are provided. The second heat generating area faces each other across the second heat generating area, and the second connecting portion is directly connected to the current of the second heat generating area at one end in the current direction of the third heat generating area. The second power feeding portion is provided at the other end in the current direction of the third heat generation region so as to extend in the current orthogonal direction of the third heat generation region, A planar heating element for a window in which the second connecting portion and the second power feeding portion face each other across the third heat generating region can be provided. Also in this case, even when a resin base material is used, it is possible to provide a planar heating element for a window that can heat a desired portion with priority and heat the entire rear surface.

  (4) In the first aspect of the present invention, the second heat generating region may further include a narrow region where the width is locally narrowed. In this case, the locally heated region on the surface of the window heating element can be divided into finer regions.

  (5) In the first aspect of the present invention, the conductive sheet includes a plurality of first conductive lines extending at a distance from each other and a plurality of second conductive lines extending at a distance from each other. The conductive mesh may include a line and the first conductive line and the second conductive line intersect so that an opening is formed. In this case, the first heat generation region, the second heat generation region, and the third heat generation region can be created separately only by cutting the conductive mesh, and by folding the periphery of the conductive mesh, Since a 1st electric power feeding part, a 2nd electric power feeding part, a 1st connection part, and a 2nd connection part can be formed, the heat generating body 2 can be formed easily.

  (6) In the first aspect of the present invention, the first conductive line extends in the first direction, and the second conductive line extends in a second direction different from the first direction. The conductive mesh may be configured by weaving the first conductive line and the second conductive line. In this case as well, the first heat generation region, the second heat generation region, and the third heat generation region can be created separately only by cutting the conductive mesh, and by folding the periphery of the conductive mesh, Since a 1st electric power feeding part, a 2nd electric power feeding part, a 1st connection part, and a 2nd connection part can be formed, the heat generating body 2 can be formed easily.

  (7) In the first aspect of the present invention, the first conductive wire has a first core wire and a first covering material that covers the outer surface of the first core wire, and the second conductive wire is the first conductive wire. 2 core wire and a second covering material covering the outer surface of the second core wire, the first core wire and the second core wire containing resin, the first covering material and the second covering material The material may include a conductive material, and the first conductive line and the second conductive line may be fixed. In this case as well, the first heat generation region, the second heat generation region, and the third heat generation region can be created separately only by cutting the conductive mesh, and by folding the periphery of the conductive mesh, Since a 1st electric power feeding part, a 2nd electric power feeding part, a 1st connection part, and a 2nd connection part can be formed, the heat generating body 2 can be formed easily.

  (8) According to the 2nd aspect which is another example of this invention, the vehicle window containing the planar heating element for windows of the 1st aspect of this invention can be provided. Since the vehicle window according to the second aspect of the present invention includes the planar heating element for window according to the first aspect of the present invention, a resin capable of preferentially heating a desired portion and heating the entire rear surface thereof. It can be a window. The resin window is very useful as a vehicle window because it can be significantly reduced in weight while having the same transparency as a glass window. In particular, the planar heating element for windows according to the first and second embodiments can preferentially heat the center of the surface and heat the entire rear surface. It is suitable for the rear window of an automobile. The vehicle window is a window used for a vehicle such as an automobile. That is, the vehicle window according to the second aspect of the present invention means that the window heating element itself according to the first aspect of the present invention is used as a vehicle window such as a rear window of an automobile. .

  As described above, the embodiments of the present invention have been described, but it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The planar heating element for a window according to one aspect of the present invention has transparency such as a vehicle window with a defogger function, a housing window glass with a defogger function, and a refrigerated showcase with a defogger function, such as a rear window of an automobile. It can be suitably used for a planar heating element for resin windows.

  DESCRIPTION OF SYMBOLS 1 Resin base material, 1a Liquid resin, 2 Heat generating body, 2a 1st heat generating area, 2b 2nd heat generating area, 2b1 Narrow area | region, 2b2 area | region, 2c 3rd heat generating area, 3a 1st electric power feeding part, 3b 2nd electric power feeding part, 4a 1st connection part, 4b 2nd connection part, 10a surface, 10b back surface, 20 electroconductive member, 21 1st conductive wire, 21a 1st core wire, 21b 1st coating | covering material , 22 second conductive wire, 22a second core wire, 22b second covering material, 23 intersection, 24 opening, 31 first direction, 32 second direction, 41, 42 mold, 41a bottom surface, 42a Surface, 43 inlet, 61 conductive substrate, 100 transparent conductive thin film, 101 upper part, 102 middle part, 103 lower part, 104 electrode.

Claims (8)

A resin base material having a planar or curved surface;
A heating element comprising a conductive sheet provided on the resin base material,
The heating element includes a first heat generation area, a second heat generation area, and a third heat generation area, which are spread out in a plane along the shape of the surface of the resin base material, and are divided into each other. A first connection portion that connects the first heat generation region and the second heat generation region in series; a second connection portion that connects the second heat generation region and the third heat generation region in series; A first power feeding section provided on a side of the first heat generating area facing the side on which the first connecting section is provided for supplying a current from an external power source; and the third heat generating area. A second power feeding portion provided on a side opposite to the side on which the second connection portion is provided,
The width in the direction orthogonal to the direction in which the current in the second heat generation region flows is orthogonal to the width in the direction in which the current in the first heat generation region flows and the direction in which the current in the third heat generation region flows. A planar heating element for a window, which is narrower than the width in the direction in which it is made.   The first connection part, the second connection part, the first power supply part, and the second power supply part are respectively the first heat generation region, the second heat generation region, and the third heat generation. The planar heating element for windows according to claim 1, wherein end portions of the conductive sheets are laminated so as to be thicker than the region. The first power supply unit is provided at one end in the direction in which the current in the first heat generation region flows so as to extend in a direction orthogonal to the direction in which the current in the first heat generation region flows.
The first connection portion is provided at the other end in the direction in which the current in the first heat generation region flows so as to extend in a direction orthogonal to the direction in which the current in the first heat generation region flows.
The first power supply unit and the first connection unit are opposed to each other across the first heat generation region,
The first connection portion is provided at one end in the direction in which the current in the second heat generation region flows so as to extend in a direction orthogonal to the direction in which the current in the second heat generation region flows.
The second connection portion is provided at the other end in the direction in which the current in the second heat generation region flows so as to extend in a direction orthogonal to the direction in which the current in the second heat generation region flows.
The first connection portion and the second connection portion face each other across the second heat generation region,
The second connection portion is provided at one end in the direction in which the current in the third heat generation region flows so as to extend in a direction perpendicular to the direction in which the current in the second heat generation region flows.
The second power feeding unit is provided at the other end in the direction in which the current in the third heat generation region flows so as to extend in a direction orthogonal to the direction in which the current in the third heat generation region flows.
3. The planar heating element for a window according to claim 1, wherein the second connection portion and the second power feeding portion face each other across the third heat generation region.   The said 2nd heat_generation | fever area | region is a planar heating element for windows of any one of Claims 1-3 which further has a narrow area | region where the said width | variety is narrowed locally.   The conductive sheet includes a plurality of first conductive lines extending at intervals and a plurality of second conductive lines extending at intervals, and an opening is formed. The planar heating element for windows according to any one of claims 1 to 4, wherein the window heating element is a conductive mesh formed by intersecting the first conductive line and the second conductive line. The first conductive line extends in a first direction;
The second conductive line extends in a second direction different from the first direction;
The planar heating element for a window according to claim 5, wherein the conductive mesh is formed by weaving the first conductive wire and the second conductive wire. The first conductive wire includes a first core wire and a first covering material that covers an outer surface of the first core wire,
The second conductive wire has a second core wire and a second covering material that covers the outer surface of the second core wire,
The first core wire and the second core wire include a resin,
The first covering material and the second covering material include a conductive material,
The planar heating element for windows according to claim 5 or 6, wherein the first conductive line and the second conductive line are fixed.   A vehicle window comprising the window heating element according to any one of claims 1 to 7.

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