JP6670466B2 - Heating plates, windows for vehicles and buildings - Google Patents

Description

  The present invention relates to a heating plate having a heating conductor, and a vehicle or building window having the heating plate.

  Conventionally, a heating plate that generates heat when a voltage is applied has been known. As a typical application example, a transparent heating plate is used as a defroster device or a heater. A heating plate as a defroster device is used as a window glass such as a windshield of a vehicle or a rear window. For example, in Patent Documents 1 and 2, a see-through heat generating plate is used as a window glass. The heating plate has a heating conductor made of a tungsten wire or the like arranged over the entire heating plate. In this heat generating plate, the temperature of the heat generating conductor is increased by resistance heating when the heat generating conductor is energized. By raising the temperature of the window glass formed of the heat generating plate, the fogging of the window glass can be removed, or snow and ice attached to the window glass can be melted, and the transparency through the window glass can be secured.

JP 2013-173402 A JP-A-8-72674

  In a conventional heating plate, a conductive thin wire of a heating conductor extends linearly to connect a pair of bus bars. In such a heat generating plate, a portion where heat cannot be generated due to disconnection of the heat generating conductor occurs, and heat generation unevenness occurs. As a result of intensive studies by the present inventors, it has been found that the easiness of disconnection of the conductive thin wire of the heating conductor depends on the width of the conductive thin wire. When the conductive thin wires are arranged in a curved shape, particularly in a portion having a large curvature, disconnection is likely to occur in a portion having a small line width due to etching in a manufacturing process.

  To reduce the possibility of disconnection, it is conceivable to increase the line width of the conductive thin line. However, when the line width is increased, the conductive thin line is visually recognized in the appearance of the heating plate, and the visibility and design are deteriorated. . Therefore, the distribution of the line width of the conductive thin wires needs to be in a range where disconnection is unlikely to occur and is not visually recognized. The present invention has been made in consideration of the above points, and has as its object to provide a heat generating plate in which a conductive thin wire of a heat-generating conductor hardly breaks and a conductive thin wire is not visually recognized.

The heating plate according to the present invention is a heating plate that generates heat when a voltage is applied,
A pair of glass,
A pair of busbars to which a voltage is applied,
A heating conductor for connecting between the pair of bus bars,
The heating conductor includes a plurality of conductive thin wires extending linearly between the pair of bus bars and connecting the bus bars.
The average W _ave of the width W of the conductive thin wire is within the range of the following equation (a) with respect to the standard deviation σ of the distribution of the width W.
0 ≦ 4σ / W _ave ≦ 0.3 Expression (a)

In the heating plate according to the present invention,
The conductive thin wire includes a large curvature portion having a relatively large curvature and a small curvature portion having a relatively small curvature,
The width W of the conductive thin wire may be narrow at the large curvature portion and thick at the small curvature portion.

  A vehicle according to the present invention includes any of the above-described heating plates according to the present invention.

  A building window according to the present invention includes any of the above-described heating plates according to the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, it can make it hard to generate | occur | produce a disconnection in the electroconductive thin wire of the electrical conductor for heating of a heating plate.

FIG. 1 is a view for explaining one embodiment of the present invention, and is a perspective view schematically showing a vehicle provided with a heating plate. In particular, FIG. 1 schematically shows a vehicle having a front window constituted by a heating plate as an example of a vehicle. FIG. 2 is a diagram showing the heating plate from the normal direction of the plate surface. FIG. 3 is a cross-sectional view of the heat generating plate taken along the line III-III in FIG. FIG. 4 is a plan view showing the sheet with a conductor from the normal direction of the sheet surface, and is a plan view showing an example of the sheet with a conductor. FIG. 5 is an enlarged plan view showing a part of the conductive thin wire. FIG. 6 is an enlarged view of a cross section of the sheet with a conductor. FIG. 7 is a diagram for explaining an example of a method for manufacturing a heating plate. FIG. 8 is a diagram for explaining an example of a method for manufacturing a heating plate. FIG. 9 is a diagram for explaining an example of a method for manufacturing a heating plate. FIG. 10 is a diagram for explaining an example of a method for manufacturing a heating plate. FIG. 11 is a diagram illustrating an example of a method for manufacturing a heating plate. FIG. 12 is a diagram for explaining an example of a method for manufacturing a heating plate. FIG. 13 is a diagram illustrating an example of a method for manufacturing a heating plate. FIG. 14 is a diagram illustrating an example of a method for manufacturing a heating plate. FIG. 15 is a diagram illustrating an example of a method for manufacturing a heating plate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale and the size ratio in the vertical and horizontal directions are changed and exaggerated as appropriate for the sake of convenience of illustration and understanding.

  In the present specification, the terms “plate”, “sheet”, and “film” are not distinguished from each other based only on the difference in name. For example, the “sheet with a conductor” is a concept including a member that can be called a plate or a film. Therefore, the “sheet with a conductor” includes a “plate with a conductor (substrate)” or a “sheet with a conductor”. It cannot be distinguished from a member called "film" only by the difference in the name.

  Further, in the present specification, the “sheet surface (plate surface, film surface)” refers to a target sheet-like (plate-like, film-like) member when viewed as a whole and globally. Refers to a surface that matches the plane direction of the plate-shaped member (plate-shaped member, film-shaped member). Further, the normal direction to the sheet-shaped (film-shaped, plate-shaped) member refers to the normal direction to the sheet surface (film-surface, plate-shaped) of the sheet-shaped (film-shaped, plate-shaped) member. Point.

  Further, as used herein, the shapes and geometric conditions and their degrees are specified.For example, terms such as "parallel", "orthogonal", and "identical", and values of length and angle are strict. Without being constrained by the meaning, it should be interpreted to include a range in which a similar function can be expected.

  1 to 15 are views for explaining an embodiment according to the present invention. 1 is a diagram schematically showing an automobile having a heating plate, FIG. 2 is a diagram of the heating plate viewed from a normal direction of the plate surface, and FIG. It is a cross section of a board.

  As shown in FIG. 1, an automobile 1 as an example of a vehicle has window glasses such as a front window, a rear window, and a side window. Here, an example in which the front window 5 is configured by the heat generating plate 10 will be described. Also, the vehicle 1 has a power source 7 such as a battery.

  As shown in FIGS. 2 and 3, the heat generating plate 10 in the present embodiment includes a pair of glasses 11 and 12, a sheet 20 with a conductor disposed between the pair of glasses 11 and 12, , 12 and a pair of bonding layers 13, 14 for bonding the sheet 20 with a conductor. In the examples shown in FIGS. 1 and 2, the heating plate 10 and the glasses 11 and 12 are curved, but in other drawings, the heating plate 10 and the glasses 11 and 12 are formed into a flat plate for easy understanding. Is shown in FIG.

  The conductor-attached sheet 20 has a base film 21, a bus bar 25, and a heat-generating conductor 30 provided on a surface of the base film 21 facing the glass 11 and including a conductive thin wire 31.

  As shown in FIG. 2, the heating plate 10 has a wiring portion 15 for supplying electricity to the heating conductor 30 of the sheet 20 with a conductor via the bus bar 25. In the illustrated example, power is supplied to the heating conductor 30 from the power source 7 such as a battery via the wiring portion 15 and the bus bar 25, and the conductive thin wire 31 of the heating conductor 30 is heated by resistance heating. The heat generated by the heat generating conductor 30 is transmitted to the glasses 11 and 12, and the glasses 11 and 12 are heated. As a result, it is possible to remove the fogging due to the condensation attached to the glasses 11 and 12. If snow or ice is attached to the glasses 11 and 12, the snow or ice can be melted. Therefore, the occupant's view can be ensured well.

  Hereinafter, each component of the heating plate 10 will be described.

  First, the glasses 11 and 12 will be described. When the glasses 11 and 12 are used for a front window of an automobile as in the example shown in FIG. 1, it is preferable to use glasses having a high visible light transmittance so as not to obstruct the occupant's view. Examples of the material of the glasses 11 and 12 include soda lime glass and blue plate glass. It is preferable that the transmittance of the glasses 11 and 12 in the visible light region is 90% or more. Here, the visible light transmittance of the glasses 11 and 12 was measured using a spectrophotometer (“UV-3100PC” manufactured by Shimadzu Corporation, JIS K 0115 compliant) within a measurement wavelength range of 380 nm to 780 nm. At this time, it is specified as an average value of the transmittance at each wavelength. The visible light transmittance may be reduced by coloring a part or the whole of the glasses 11 and 12. In this case, it is possible to block direct sunlight and make it difficult to visually recognize the inside of the vehicle from outside.

  Further, it is preferable that the glasses 11 and 12 have a thickness of 1 mm or more and 5 mm or less. With such a thickness, the glasses 11 and 12 having excellent strength and optical characteristics can be obtained. The pair of glasses 11 and 12 may be made of the same material and may be the same, or may be different from each other in at least one of the material and the configuration.

  Next, the bonding layers 13 and 14 will be described. The first bonding layer 13 is disposed between the first glass 11 and the sheet 20 with a conductor, and bonds the glass 11 and the sheet 20 with a conductor to each other. The second bonding layer 14 is disposed between the second glass 12 and the sheet 20 with a conductor, and bonds the glass 12 and the sheet 20 with a conductor to each other.

  As such bonding layers 13 and 14, layers made of various adhesive or tacky materials can be used. In addition, it is preferable that the bonding layers 13 and 14 have high visible light transmittance. As a typical bonding layer, a layer made of polyvinyl butyral (PVB) can be exemplified. It is preferable that the thickness of each of the bonding layers 13 and 14 is 0.15 mm or more and 1 mm or less. The pair of bonding layers 13 and 14 may be made of the same material and may be the same, or may be different from each other in at least one of the material and the configuration.

  The heating plate 10 is not limited to the illustrated example, and may be provided with another functional layer expected to exhibit a specific function. In addition, one functional layer may perform two or more functions. For example, the glass layers 11 and 12 of the heating plate 10, the bonding layers 13 and 14, and the base film of the conductive sheet 20 described later may be used. At least one of the functions 21 may be provided with some function. Examples of the functions that can be provided to the heating plate 10 include an anti-reflection (AR) function, a hard coat (HC) function having scratch resistance, an infrared shielding (reflection) function, an ultraviolet shielding (reflection) function, and an antifouling property. Functions and the like can be exemplified.

  Next, the conductive sheet 20 will be described. The conductor-attached sheet 20 has a base film 21, a bus bar 25, and a heat-generating conductor 30 provided on a surface of the base film 21 facing the glass 11 and including a conductive thin wire 31. The conductor-equipped sheet 20 may have substantially the same plane dimensions as the glasses 11 and 12 and may be disposed over the entire heat generating plate 10 or may be disposed on the heat generating plate 10 such as the front portion of the driver's seat in the example of FIG. May be arranged only in a part of.

  The base film 21 functions as a base for supporting the heat generating conductor 30. The base film 21 is a generally transparent and electrically insulating substrate that transmits a wavelength in the visible light wavelength band (380 nm to 780 nm). As the base film 21, any material may be used as long as it can transmit visible light and appropriately support the heat generating conductor 30, and examples thereof include polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, and cyclic. Polyolefin and the like can be mentioned. In addition, it is preferable that the base film 21 have a thickness of 0.03 mm or more and 0.20 mm or less in consideration of light transmittance, appropriate supportability of the heat generating conductor 30, and the like.

  Next, the heat generating conductor 30 will be described with reference to FIG. FIG. 4 is a plan view showing the heating conductor 30 from the normal direction of the sheet surface. FIG. 4 is a diagram illustrating an example of an arrangement of the heating conductor 30.

  As shown in FIG. 4, the heat generating conductor 30 has a plurality of linear conductive thin wires 31 connecting the pair of bus bars 25. The conductive thin wire 31 is energized from the power source 7 such as a battery via the wiring portion 15 and the bus bar 25, and generates heat by resistance heating. Then, the heat is transmitted to the glasses 11 and 12 via the bonding layers 13 and 14, so that the glasses 11 and 12 are heated.

  In the example shown in FIG. 4, each of the plurality of conductive wires 31 extends from one bus bar 25 to the other bus bar 25. The plurality of conductive thin wires 31 are arranged apart from each other. In particular, the plurality of conductive thin wires 31 are arranged in a direction orthogonal to the direction in which the conductive thin wires 31 extend. A gap 35 is formed between two adjacent conductive thin wires 31.

  Examples of a material for forming the heating conductor 30 include metals such as gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, and tungsten; One or more alloys of two or more metals selected from these exemplified metals such as chromium alloys and brass can be exemplified.

  The heat generating conductor 30 can be formed using an opaque metal material as described above. On the other hand, the conductive thin wires 31 of the heating conductor 30 are formed with a high non-coverage ratio of about 70% or more and 90% or less. For this reason, the region where the conductive thin wires 31 and the connection conductive thin wires 32 of the heat generating conductor 30 are formed is grasped as transparent as a whole, so that visibility is not impaired.

  In the example shown in FIG. 3, the conductive fine wire 31 has a substantially trapezoidal cross section as a whole. More precisely, the side surface of the conductive thin wire 31 has a concave curved surface shape due to etching in a manufacturing process described later. The width W of the bottom of the conductive thin wire 31, that is, the length along the plate surface of the heating plate 10 is 11 μm or more and 20 μm or less, and the height (thickness) H, ie, the height of the heating plate 10 to the plate surface. The height (thickness) along the normal direction is preferably 1 μm or more and 60 μm or less. According to the conductive thin wire 31 having such a size, the conductive thin wire 31 is sufficiently thinned, so that the heating conductor 30 can be effectively made invisible.

  As shown in FIG. 3, the conductive thin wire 31 is formed of a conductive metal layer 36 and a first dark layer covering a surface of the surface of the conductive metal layer 36 that faces the base film 21. 37, a second dark-colored layer 38 covering the surface of the conductive metal layer 36 on the side facing the glass 11 and both side surfaces.

  The conductive metal layer 36 made of a metal material having excellent conductivity exhibits a relatively high reflectance. When light is reflected by the conductive metal layer 36 forming the conductive thin wire 31 of the heating conductor 30, the reflected light becomes visible, which may obstruct the occupant's view. Further, when the conductive metal layer 36 is visually recognized from the outside, the design may be deteriorated. Therefore, the first and second dark layers 37 and 38 are arranged on at least a part of the surface of the conductive metal layer 36. The first and second dark layers 37 and 38 may be layers having a lower visible light reflectance than the conductive metal layer 36, and are, for example, dark layers such as black. The conductive layers 36 are less visible due to the dark layers 37 and 38, and the occupant's field of view can be secured well. In addition, it is possible to prevent the design from being deteriorated when viewed from the outside.

  Note that, as described above, the conductive thin wires 31 of the heating conductor 30 are formed on the base film 21 at a high non-coverage rate from the viewpoint of securing the transparency or visibility. For this reason, as shown in FIG. 3, the bonding layer 13 and the base film 21 of the sheet 20 with a conductor are interposed between the non-covered portion of the conductive thin wires 31, that is, the region between the adjacent conductive thin wires 31. Contact. Therefore, the heating conductor 30 is embedded in the bonding layer 13.

FIG. 5 shows an enlarged view of a part of the conductive thin wire 31 as viewed from the normal direction of the sheet surface. As a result of extensive studies by the present inventors, as shown in FIG. 5, the conductive thin wire 31 of the heating conductor 30 actually manufactured has a distribution in the line width W along the longitudinal direction thereof. Become like Such a tendency is remarkable in the heat generating conductor 30 of the sheet with conductor 20 manufactured by a manufacturing method described later with reference to FIGS. 7 to 15. Then, when the inventors of the present invention examined the relationship between the variation of the line width W and the disconnection of the conductive thin wire 31, the variation of the line width W could have a strong influence on the ease of disconnection of the conductive thin wire 31. It was confirmed that. The present inventors have confirmed that, when the average of the width W of the conductive thin wire 31 is W _ave and the standard deviation is σ, when the width W is distributed so as to satisfy the following equation (a), heat is generated. The width of the conductive thin wire 31 could be set in a range where the conductive thin wire 31 of the conductor for use 30 was hardly broken and the conductive thin wire 31 was not visually recognized.
0 ≦ 4σ / W _ave ≦ 0.3 Expression (a)

  FIG. 6 is an enlarged view of the conductive thin wire 31 on the conductor-attached sheet 20 viewed from a cross section. In FIG. 6, the conductive metal layer and the dark layer are omitted. The conductive thin wire 31 shown in FIG. 6 shows a cross section of the conductive thin wire 31 manufactured by a manufacturing method described later. In the example shown in FIG. 6, the width W of the conductive thin wire 31 changes at each position along the normal direction of the sheet with conductor 20. In the example shown in FIG. 6, the width W of the conductive thin wire 31 changes at each position along the normal direction of the sheet with conductor 20. As for the conductive thin wire 31 whose width W varies along the normal direction of the sheet 20 with a conductor, the width W of the conductive thin wire 31 refers to the maximum width in each cross section that easily affects disconnection and visualization. It shall be. That is, in the example blinded in FIG. 6, the width W of the conductive thin wire 31 indicates the width at the bottom closest to the base film 21.

  As shown in FIG. 5, the conductive thin wire 31 includes a curved portion, and not only the width of the curved portion but also the curvature are not constant. Particularly in the illustrated example, the conductive thin wire 31 is formed only by a curved portion. When the conductive thin wire 31 includes the curved portion, the generation of strong streak-like light in a specific direction due to diffraction at the conductive thin wire 31, that is, the generation of a light beam can be effectively made inconspicuous.

  As shown in FIG. 5, the curvature of the curved portion of the conductive thin wire 31 is not constant. In particular, the conductive thin wire 31 has a width W of the conductive thin wire 31 different from each other, “a portion having a relatively small curvature (small curvature portion; see reference numeral“ A ”in FIG. 5)” and “a relatively large curvature. (A first large curvature portion; see reference numeral “B” in FIG. 5)). The width W of the main conductive thin wire 31 is large in a small curvature portion A having a relatively small curvature and small in a large curvature portion B having a relatively large curvature. The present inventors have conducted intensive research and found that the width W of the conductive main fine wire 31 is large in the small curvature portion A and narrow in the large curvature portion B, so that the small curvature portion A is visually recognized as dots. Is effectively prevented, and as a result, the heating conductor 30 can be effectively made invisible.

  Next, an example of a method for manufacturing the heating plate 10 will be described with reference to FIGS. 7 to 10 and 13 to 15 are cross-sectional views sequentially illustrating an example of a method of manufacturing the heating plate 10. FIG. 11 and FIG. 12 are diagrams illustrating the distribution of an etching solution for etching described later.

  First, as shown in FIG. 7, a dark color film 37 a for forming the first dark color layer 37 is provided on the base film 21. As the base film 21, any material may be used as long as it can appropriately hold the heating conductor 30, and examples thereof include polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polystyrene, and cyclic polyolefin. it can. Further, in consideration of the holding property of the heat generating conductor 30 and the like, it is preferable to use the base film 21 having a thickness of 30 μm or more and 150 μm or less. The dark film 37a can be provided by, for example, a plating method including electrolytic plating and electroless plating, a sputtering method, a CVD method, a PVD method, an ion plating method, or a method combining two or more of these methods. Various known materials can be used as the material of the dark film 37a. For example, copper nitride, copper oxide, nickel nitride and the like can be exemplified.

  Next, as shown in FIG. 8, a metal film 36a for forming the conductive metal layer 36 is provided on the dark film 37a. As described above, the metal film 36a is made of gold, silver, copper, platinum, aluminum, chromium, molybdenum, nickel, titanium, palladium, indium, tungsten, and alloys thereof, as described above as the material forming the conductive metal layer 36. It can be formed using one or more. The metal film 36a can be formed by a known method. For example, a method of attaching a metal foil such as a copper foil, a plating method including electroplating and electroless plating, a sputtering method, a CVD method, a PVD method, an ion plating method, or a method combining two or more of these methods is employed. can do.

  Next, as shown in FIG. 9, a resist pattern 39 is provided on the metal film 36a, and a material to be etched (in the illustrated example, a sheet-like member to be etched) 40 is formed. The resist pattern 39 has a shape corresponding to the heating conductor 30 to be formed. In the method described here, the resist pattern 39 is provided only on the portion that will eventually form the heating conductor 30. This resist pattern 39 can be formed by patterning using a known photolithography technique.

  Next, as shown in FIG. 10, using the resist pattern 39 as a mask, the metal film 36a and the dark color film 37a of the material to be etched 40 are etched. By this etching, the metal film 36a and the dark color film 37a are patterned into the same pattern as the resist pattern 39. As a result, a conductive metal layer 36 that forms a part of the conductive thin wire 31 is formed from the patterned metal film 36a. In addition, the first dark layer 37 that forms a part of the conductive thin wire 31 and the connection conductive thin wire 32 is formed from the patterned dark color film 37a.

  Here, the etching method will be described with reference to FIGS. First, as shown in FIG. 11, the material to be etched (in the illustrated example, a sheet-like member to be etched) 40 is moved in the direction of the arrow. At this time, the extending direction of the resist pattern 39, that is, the extending direction of the conductive metal layer 36 generated after the etching, and the traveling direction of the material to be etched 40 are made to coincide. Then, an etchant is sprayed on the moving target material 40 from a spray 50 provided above the target material 40. At this time, the etching liquid is sprayed while the spray 50 is oscillated perpendicularly to the traveling direction of the material 40 to be etched. According to this embodiment, the etching solution can be uniformly sprayed in a direction perpendicular to the direction in which the resist pattern 39 extends. In addition, by adjusting the amount of the etchant sprayed from the spray 50 and the progress speed of the material to be etched 40, the degree of progress of etching with respect to the whole material to be etched 40 can be adjusted.

  When the etching solution is sprayed as described above, the etching progresses relatively slowly in a portion where the curvature of the resist pattern 39 is small, such as the region A 'in FIG. 12, because the etching solution remains diffused. Therefore, the width of the conductive metal layer 36 that finally forms the conductive thin wire 31 is increased. That is, in the small curvature portion A shown in FIG. 5, the line width W of the conductive thin wire 31 becomes relatively large. On the other hand, as the etching liquid concentrates on a portion where the curvature of the resist pattern 39 is larger, such as the region B ', the etching proceeds relatively quickly. Therefore, the width of the conductive metal layer 36 that finally forms the conductive thin wire 31 is reduced. That is, in the large curvature portion B shown in FIG. 5, the line width W of the conductive thin wire 31 becomes relatively thin. That is, according to the etching method shown in FIG. 11, the curvature of the resist pattern 39, that is, the conductivity to be formed, is adjusted by adjusting the amount of the etchant sprayed from the spray 50 and the traveling speed of the material to be etched 40. The width W of the conductive thin wire 31 can be controlled according to the curvature of the conductive thin wire 31.

  As described above, the width of the conductive metal layer 36 that ultimately forms the conductive thin wire 31 can be easily adjusted by the amount of the etching solution sprayed on the resist pattern 39 and the traveling speed of the material 40 to be etched. The etching is adjusted so as not to proceed excessively at a location where the curvature of the resist pattern 39 is large. As described above, the material to be etched 40 is etched to form the conductive metal layer 36 and the first dark layer 37. Thereafter, as shown in FIG. 13, the resist pattern 39 is removed.

  Next, as shown in FIG. 14, a second dark layer 38 is formed on the surface 31a of the conductive metal layer 36 opposite to the surface 31b on which the first dark layer 37 is provided, and on the side surfaces 31c and 31d. The second dark layer 38 is formed, for example, by subjecting a part of the material forming the conductive metal layer 36 to a darkening process (blackening process), and from the part forming the conductive metal layer 36 to a metal oxide or metal sulfide. The second dark color layer 38 made of an object can be formed. Further, a second dark layer 38 may be provided on the surface of the conductive metal layer 36 such as a coating film of a dark material or a plating layer of nickel, chromium, or the like. Further, the surface of the conductive metal layer 36 may be roughened to provide the second dark layer 38. Through the above steps, the sheet with conductor 20 is manufactured.

  Finally, as shown in FIG. 15, the bonding layer 13 and the glass 11 are laminated from the side of the heat generating conductor 30 of the sheet 20 with the conductor, and the sheet 20 with the conductor and the glass 11 are To join. Similarly, the bonding layer 14 and the glass 12 are laminated from the side of the base film 21, and the sheet 20 with a conductor and the glass 12 are bonded. Thus, the heating plate 10 shown in FIG. 3 is manufactured.

As described above, the heat generating plate 10 according to the present embodiment is a heat generating plate that generates heat when a voltage is applied, and includes a pair of glasses 11 and 12, a pair of bus bars 25 to which a voltage is applied, and a pair of bus bars 25. A heating conductor 30 connecting between the bus bars 25; the heating conductor 30 includes a plurality of conductive thin wires 31 extending linearly between the pair of bus bars 25 and connecting the bus bars 25; The average W _ave of the width W at the bottom of 31 is within the range of the following equation (a) with respect to the standard deviation σ of the distribution of the width W.
0 ≦ 4σ / W _ave ≦ 0.3 Expression (a)
According to such a heating plate 10, since the difference in the width W at the bottom of the conductive thin wire 31 is small as a whole, the conductive thin wire 31 of the heating conductor 30 is hardly disconnected, and the conductive thin wire 31 is visually recognized. The width of the conductive thin wire 31 can be set in a range not to be performed. For this reason, heat generation unevenness hardly occurs in the heat generation plate 10 and a good visual field through the heat generation plate 10 can be obtained.

  In the heat generating plate 10 according to the present embodiment, the conductive thin wire 31 has a large curvature portion B having a relatively large curvature of the pattern in a plan view and a small curvature portion A having a relatively small curvature of the pattern in a plan view. And The width W of the conductive thin wire 31 is small in the large curvature portion B and large in the small curvature portion A. According to the present embodiment, the heating conductor 30 can be effectively made invisible.

  The heat generating plate 10 may be used for a front window, a side window, or a sunroof of the automobile 1. Further, it may be used for windows or transparent doors of vehicles other than automobiles, such as railway vehicles, aircraft, ships, and spaceships.

  Further, the heat generating plate 10 can be used as a part other than the vehicle, particularly as a part for separating the room from the outside, for example, a window of a building such as a building, a store, a house, or a transparent door.

  Note that various changes can be made to the above-described embodiment.

REFERENCE SIGNS LIST 1 automobile 5 front window 7 power supply 10 heating plate 11 glass 12 glass 13 bonding layer 14 bonding layer 15 wiring section 20 sheet with conductor 21 base film 25 bus bar 30 conductor for heating 31 conductive thin wire 35 gap 36 conductive metal layer 37 first dark color layer 38 second dark color layer 39 resist pattern

Claims (3)

A heating plate that generates heat when voltage is applied,
A pair of glass,
A pair of busbars to which a voltage is applied,
A heating conductor for connecting between the pair of bus bars,
The heating conductor includes a plurality of conductive thin wires extending linearly between the pair of bus bars and connecting the bus bars.
Average W _ave of the width W of the electroconductive thin line is, relative to the standard deviation σ of the distribution of the width W, Ri range der the following formula (a),
The conductive thin wire includes a large curvature portion having a relatively large curvature and a small curvature portion having a relatively small curvature,
The heating plate, wherein the width W of the conductive thin wire is thin at the large curvature portion and thick at the small curvature portion.
0 ≦ 4σ / W _ave ≦ 0.3 Expression (a) A vehicle comprising the heating plate according to claim 1 . A building window provided with the heating plate according to claim 1 .

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