wall panels

Abstract

To provide a wall plate capable of providing a sense of depth in comparison with a plate thickness.SOLUTION: A wall plate 100 has at least one inclined part 10 on the surface. The inclined part 10 extends in the right and left direction and is inclined to the front side from the upper part to the lower part, and an uneven pattern 11 is formed on the surface. The uneven pattern 11 is formed so as to become shallower from the lower side toward the upper side, It is preferable that the uneven pattern 11 gradually becomes smaller in size from the lower side toward the upper side when the inclined portion 10 is viewed from the front.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wallboard, and more particularly to a wallboard having a sloped surface. [Background technology]

[0002] Patent Document 1 describes an architectural wall panel. This architectural wall panel has a male joint, a slope, and a female joint. It also has a groove between each slope, and a trough-shaped recess at the boundary between the male joint and the decorative surface. Furthermore, the architectural wall panel has a groove-shaped recess at a position opposite the groove on the back side of the wall panel, and a valley-shaped recess on the back side opposite the trough-shaped recess.

[0003] The above-mentioned architectural wallboards have a number of sloped surfaces on their surfaces, giving them an armor-like appearance. The sloped surfaces also give the architectural wallboards a three-dimensional appearance (a sense of depth). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-22143 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned armor-like architectural wall panel, if one wishes to emphasize the three-dimensional effect of each slope, one could consider increasing the inclination angle of the slope, but this would result in portions of the architectural wall panel being extremely thin. Therefore, when one wishes to emphasize the three-dimensional effect of each slope, the thickness of the panel has been limited.

[0006] The present invention has been made in view of the above-mentioned circumstances, and aims to provide a wallboard that can easily achieve a three-dimensional appearance in relation to its thickness. [Means for solving the problem]

[0007] A wall panel according to one aspect of the present invention has at least one inclined portion on its surface, which extends in the left-right direction and slopes forward from top to bottom, and has a concave-convex pattern formed on its surface, the concave-convex pattern being shallower from bottom to top. [Effects of the Invention]

[0008] According to the present invention, a wallboard is obtained that is likely to give a three-dimensional appearance in relation to its thickness. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an enlarged cross-sectional view of a portion of a wall panel according to an embodiment of the present invention. [Figure 2] Figure 2A is a front view of an embodiment of a wall panel according to the present invention, and Figure 2B is a side view of an embodiment of the wall panel according to the present invention. [Figure 3] 3A and 3B are enlarged cross-sectional views of a portion of a conventional example. [Figure 4] 4A to 4D are perspective views of a portion of a wall panel according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Embodiment 1) (1) Overview The wall panel 100 of this embodiment has at least one inclined portion 10 on its surface (see FIGS. 2A and 2B). The inclined portion 10 extends in the left-right direction and is inclined forward from top to bottom. A concave-convex pattern 11 is formed on the surface of the inclined portion 10 (see FIG. 1). The concave-convex pattern 11 is formed so as to become shallower from bottom to top.

[0011] In the wall panel 100 of this embodiment, when viewed from the front, the shadows cast by the uneven pattern 11 become stronger toward the lower part of the inclined portion 10, and the shadows cast by the uneven pattern 11 become vaguer toward the upper part of the inclined portion 10.

[0012] Conventionally, this type of wall panel 100a, 100b has either a textured pattern 11a of a fixed shape (fixed depth of texture) formed on the surface of the inclined portion 10a, as shown in Fig. 3A, or a flat surface formed on the surface of the inclined portion 10b, as shown in Fig. 3B. With such wall panels 100a, 100b, the three-dimensional effect is imparted solely by the gradient of the inclination angle of the inclined portions 10a, 10b, making it difficult to emphasize the three-dimensional effect.

[0013] On the other hand, in the wall panel 100 of this embodiment, a three-dimensional effect is imparted not only by the varying inclination angles of the inclined portions 10 but also by the variations in the uneven pattern 11. That is, when the wall panel 100 is viewed from the front, the convex portions of the uneven pattern 11 are located closer to the viewer than the concave portions in the lower portion of the inclined portions 10 compared to the upper portion, and the concave portions are more likely to be in the shadow of the convex portions. This results in a greater contrast between the convex portions, which are more easily exposed to light, and the concave portions, which are less easily exposed to light.

[0014] On the other hand, when the wall panel 100 is viewed from the front, the upper part of the slope 10 has almost no difference in the position of the convex and concave portions of the textured pattern 11 compared to the lower part, making it closer to a flat surface. Therefore, the concave portions are less likely to be shaded by the convex portions, and the contrast between the light and dark of the convex and concave portions is smaller.

[0015] As a result, the shadows of the uneven pattern 11 are stronger in the lower part of the inclined portion 10 than in the upper part, and conversely, the shadows of the uneven pattern 11 are less clear in the upper part of the inclined portion 10 than in the lower part.

[0016] The difference in shading between the lower and upper portions of the inclined portion 10 due to the uneven pattern 11 makes the upper portion appear to be located further back and the lower portion appear to be located closer to the front. This creates a sense of depth relative to the thickness of the wallboard 100. In other words, the thickness of the wallboard 100 has less of an effect on the three-dimensional appearance of the wallboard 100. For example, a sense of depth can be easily achieved even if the wallboard 100 is thin. Furthermore, a sense of depth can be easily achieved even if the inclination angle of the inclined portion 10 is not gentle (close to a vertical surface).

[0017] In this specification, directions are indicated based on the installed state of the wall panel 100. FIG. 2A is a front view of the wall panel 100. This front view is a drawing of the wall panel 100 as seen from the front. The dimension of the wall panel 100 in the left-right direction (horizontal direction) is longer than the dimension in the up-down direction (vertical direction). The direction perpendicular to both the left-right direction and the up-down direction is the front-to-back direction. As shown in FIG. 2B, the front-to-back direction is the same as the direction of the thickness of the wall panel 100.

[0018] (2)Details The wall panel 100 of this embodiment is a ceramic siding material. The ceramic siding material is an exterior wall material obtained by molding a hydraulic composition containing cement, aggregate, reinforcing fiber, water, etc. into a desired shape and then curing it.

[0019] As shown in Fig. 2A, the wall panel 100 of this embodiment is formed as a rectangular plate extending in the left-right direction when viewed from the front. Therefore, the wall panel 100 is formed to be long in the left-right direction and short in the up-down direction. The size of the wall panel 100 is, for example, 455 mm in the up-down direction, 3030 mm in the left-right direction, and 10 to 30 mm in the front-to-back direction (plate thickness), but is not limited to these sizes.

[0020] The wall panel 100 of this embodiment has at least one inclined portion 10 on its surface. The surface of the wall panel 100 is the front surface, which faces away from the wall substrate when installed on a wall substrate such as a furring strip. Therefore, the surface of the wall panel 100 is the surface that forms the wall surface of the exterior wall of the building. The back surface of the wall panel 100 is the rear surface, which faces the wall substrate when installed on the wall substrate. The back surface of the wall panel 100 is composed of a flat surface.

[0021] The wall panel 100 of this embodiment has one or more inclined portions 10. The wall panel 100 shown in FIGS. 2A and 2B has four inclined portions 10, but is not limited to this. The multiple inclined portions 10 are formed side by side in the vertical direction. A groove portion 14 is provided between adjacent inclined portions 10 in the vertical direction. Since the wall panel 100 of this embodiment has four inclined portions 10, there are three groove portions 14. The groove portions 14 are formed to be recessed rearward from the surface of the inclined portion 10.

[0022] Each inclined portion 10 is formed to extend in the left-right direction. Each inclined portion 10 is formed over the entire length of the wall panel 100 in the left-right direction. Therefore, the grooves 14 provided between adjacent inclined portions 10 in the vertical direction are also formed over the entire length of the wall panel 100 in the left-right direction. Each inclined portion 10 is inclined with respect to the vertical direction. The inclined portions 10 are inclined forward from top to bottom. That is, the inclined portions 10 are inclined so that the lower portions are located further forward than the upper portions. The lower portions of the inclined portions 10 are located below the vertical center of the inclined portions 10. The upper portions of the inclined portions 10 are located above the vertical center of the inclined portions 10. The inclination angle of the inclined portions 10 with respect to the vertical direction is approximately constant. Therefore, the lower end of the inclined portion 10 is the forward-most portion of the inclined portion 10. The inclination angle D of the inclined portions 10 with respect to the vertical direction can be 2 to 4 degrees, but is not limited thereto. In the wall panel 100 of this embodiment, all of the inclined portions 10 have the same inclination angle D. Therefore, the inclination directions of the multiple inclined portions 10 are parallel to one another. The difference in thickness between the upper and lower ends of the inclined portions 10 (height difference of the inclined portions 10) is not particularly limited, but can be 3 to 6 mm. This difference corresponds to the difference in the positions of the upper and lower ends of the inclined portions 10 in the front-to-rear direction.

[0023] When the wall panel 100 of this embodiment has multiple inclined portions 10 aligned vertically, it has an armor-like (clapboard-like) appearance. The armor-like appearance refers to an appearance in which the plate material is armor-clad (clapboard-like). Armor-clad is a structure in which, when multiple plate materials are laid horizontally, parts of adjacent plate materials are overlapped with each other. In the wall panel 100 of this embodiment, one inclined portion 10 is visually recognized as a single plate material, and multiple inclined portions 10 are aligned vertically, so that multiple plate materials appear to be aligned vertically with parts overlapping. Therefore, even if the wall panel 100 is a single piece of wall panel, it has an armor-like appearance made up of multiple plate materials.

[0024] In the wall panel 100 of this embodiment, an uneven pattern 11 is formed on the surface of each inclined portion 10. The uneven pattern 11 is a pattern formed by a collection of multiple convex portions 111 and multiple concave portions 112. The uneven pattern 11 is, for example, a matte pattern. The uneven pattern 11 may also be, for example, a wood grain pattern or a grained pattern. The uneven pattern 11 is formed by providing concave portions 112 around the convex portions 111. Therefore, concave portions 112 are formed between adjacent convex portions 111. The convex portions 111 protrude forward more than the concave portions 112. When the uneven pattern 11 is a matte pattern, for example, the convex portions 111 can be formed by hemispherical protrusions, and the concave portions 112 can be formed by flat or concave surfaces. When the uneven pattern 11 is a wood grain pattern, for example, the convex portions 111 can be formed by curved protrusions, and the concave portions 112 can be formed by flat or concave surfaces.

[0025] The uneven pattern 11 is formed so that it becomes shallower from bottom to top. That is, the uneven pattern 11 is formed so that the depth of the recessed portions 112 becomes shallower along the inclination direction of the inclined portion 10 from bottom to top. In other words, the recessed portions 112 located in the upper portion of the inclined portion 10 are located further forward than the recessed portions 112 located in the lower portion of the inclined portion 10, and the unevenness between the convex portions 111 and the recessed portions 112 of the uneven pattern 11 becomes smaller from bottom to top. In other words, the depth of the recessed portions 112 in the upper portion of the inclined portion 10 (the dimension between the front end of the convex portion 111 and the rear end of the recessed portions 112) is smaller than the depth of the recessed portions 112 in the lower portion of the inclined portion 10.

[0026] In such a wall panel 100, when viewed from the front, the shadow cast by the uneven pattern 11 becomes stronger toward the lower portion of the inclined portion 10, and the shadow cast by the uneven pattern 11 becomes vaguer toward the upper portion. Furthermore, since the inclined portion 10 is inclined so that the upper portion is positioned further back than the lower portion, the shadow cast by the uneven pattern 11 becomes stronger toward the front of the inclined portion 10 (closer to the viewer in a front view), and the shadow cast by the uneven pattern 11 becomes vaguer toward the rear (farther from the viewer in a front view). Therefore, the wall panel 100 appears to be positioned further back toward the upper portion, and the inclination of the inclined portion 10 appears to be emphasized compared to the actual inclination angle D (appearing to be inclined at a greater angle than the actual inclination angle D). As a result, the wall panel 100 provides a sense of depth (three-dimensionality or perspective) relative to its thickness.

[0027] The concave-convex pattern 11 is preferably formed so that the depth of the recessed portions 112 gradually decreases along the inclination direction from the bottom to the top of the inclined portion 10. In this case, the concave-convex pattern 11 changes in a gradational manner from the bottom to the top. The recessed portion 112 located at the bottom of the inclined portion 10 has the largest dimension in the front-to-back direction (the deepest) compared to the other recessed portions 112. The recessed portion 112 located at the top of the inclined portion 10 has the smallest dimension in the front-to-back direction (the shallowest) compared to the other recessed portions 112. The concave-convex pattern 11 is preferably formed so that the depth of the recessed portion 112 located at the top of the inclined portion 10 is 30 to 50% of the dimension in the front-to-back direction of the recessed portion 112 located at the bottom of the inclined portion 10. In this case, the difference in shading due to the concave-convex pattern 11 between the lower and upper portions of the inclined portion 10 increases, further emphasizing the three-dimensional effect.

[0028] When viewing the inclined portion 10 from the front, the size of the concave-convex pattern 11 preferably decreases from bottom to top. That is, the concave-convex pattern 11 is preferably formed so that the size of the convex portions 111 decreases along the inclination direction from bottom to top of the inclined portion 10. Fig. 4A shows the change in size of the convex portions 111 as a schematic representation of the density of dots.

[0029] When the convex portions 111 are hemispherical protrusions, the size of the convex portions 111 is represented by the diameter of the convex portions 111 when viewed from the front and the dimension in the front-to-rear direction (height dimension) of the convex portions 111. Therefore, when the convex portions 111 are hemispherical protrusions, it is preferable that the diameter of the convex portions 111 gradually decreases and the dimension in the front-to-rear direction gradually decreases along the inclination direction from the bottom to the top of the inclined portion 10 in the concave-convex pattern 11.

[0030] When the convex portion 111 is a curved protrusion, the size of the convex portion 111 is represented by the width of the convex portion 111 when viewed from the front and the dimension in the front-to-rear direction (height dimension) of the convex portion 111. Therefore, when the convex portion 111 is a curved protrusion, it is preferable that the width of the convex portion 111 gradually decreases and the dimension in the front-to-rear direction gradually decreases along the inclination direction from the bottom to the top of the inclined portion 10 of the uneven pattern 11.

[0031] By changing the size of the convex portions 111 in this way, the ambiguity of the shadows created by the uneven pattern 11 is emphasized toward the upper part of the inclined portion 10, enhancing the sense of depth. Furthermore, it is preferable that the uneven pattern 11 is formed so that the size of the convex portions 111 gradually decreases along the inclination direction from the bottom to the top of the inclined portion 10. In this case, the uneven pattern 11 is more likely to have a gradation-like change in shadow from the bottom to the top.

[0032] As shown in FIG. 1, it is preferable that the inclined portion 10 has a flat portion 15. The flat portion 15 is formed at the bottom of the inclined portion 10, and is located below the uneven pattern 11 and above the groove portion 14. The flat portion 15 is composed of a flat surface. Therefore, the flat portion 15 is located at the frontmost side of the inclined portion 10. The vertical dimension of the flat portion 15 can be formed to be about 10 mm, but is not limited to this.

[0033] The wall panel 100 of this embodiment has a flat portion 15 below the inclined portion 10, so that the lower portion of the inclined portion 10 appears to be located closer to the viewer (forward). Therefore, the inclination of the inclined portion 10 appears to be more emphasized than the actual inclination angle D (the inclination angle appears to be greater than the actual inclination angle D). As a result, the wall panel 100 has a sense of depth (a three-dimensional effect or a sense of perspective) compared to its thickness. The flat portion 15 may be omitted, in which case the uneven pattern 11 is formed on the entire surface of the inclined portion 10.

[0034] The wall panel 100 of this embodiment has an edge portion 18 at its upper end, and further has an upper solid portion 16 on the upper surface of the edge portion 18. The wall panel 100 also has a lower solid portion 17 at its lower end. The wall panels 100 of this embodiment are installed horizontally, lining up a plurality of them in the vertical direction to form an exterior wall. At this time, vertically adjacent wall panels 100 are arranged with their upper solid portions 16 and lower solid portions 17 connected by a slanting joint. Thus, although the wall panel 100 of this embodiment is not armor-clad, the multiple inclined portions 10 lined up vertically allow it to form an armor-clad exterior wall.

[0035] (Variation) The first embodiment is merely one of various embodiments of the present disclosure, and various modifications can be made to the first embodiment depending on the design and the like, as long as the object of the present disclosure can be achieved.

[0036] The wallboard 100 may be made of not only a ceramic siding material but also a metal siding material. The wallboard 100 may also be made of a wood board or a plastic plate.

[0037] The wall panel 100 may be used not only as an exterior wall material but also as an interior material.

[0038] The wallboard 100 may have two, three, five or more sloped portions 10.

[0039] When the wall panel 100 has a plurality of inclined portions 10, the inclination angles D of all the inclined portions 10 may be the same, or the inclination angles D of some or all of the inclined portions 10 may be different.

[0040] When the wall panel 100 has a plurality of inclined portions 10, the uneven patterns 11 of all the inclined portions 10 may be the same, or the uneven patterns 11 of some or all of the inclined portions 10 may be different.

[0041] (Embodiment 2) The wall panel 100 according to this embodiment differs from the wall panel 100 according to the first embodiment in the configuration of the inclined portion 10.

[0042] Hereinafter, the same components as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0043] The configuration described in the second embodiment can be applied in appropriate combination with the configuration described in the first embodiment (including modified examples).

[0044] The wall panel 100 of this embodiment is colored on the inclined portion 10. This color can be obtained by painting the surface of the inclined portion 10 to form a coating. The color of the inclined portion 10 gradually changes from bottom to top, becoming darker. That is, the surface of the inclined portion 10 has a color gradation in which the lower end has the lightest color and gradually changes from light to dark from the lower end to the upper end. Figure 4B shows a schematic diagram of the color change on the surface of the inclined portion 10.

[0045] The sloped portion 10 appears brighter toward the bottom end and darker toward the top end. Therefore, the lower portion of the sloped portion 10 appears to be located closer to the front (forward) than the upper portion. Therefore, the sloped portion 10 appears to have a more pronounced slope than the actual slope angle D (it appears to have a larger slope angle than the actual slope angle D). As a result, the wall panel 100 has a sense of depth (a three-dimensional effect or a sense of perspective) compared to its thickness.

[0046] In this embodiment, dark colors refer to black, brown, and the like, and light colors refer to white, gray, and the like.

[0047] (Embodiment 3) The wall panel 100 according to this embodiment differs from the wall panel 100 according to the first or second embodiment in the configuration of the inclined portion 10.

[0048] Hereinafter, the same components as those in the first or second embodiment will be denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0049] The configuration described in the third embodiment can be applied in appropriate combination with the configuration described in the first or second embodiment (including modified examples).

[0050] In the wall panel 100 of this embodiment, the entire surface of the inclined portion 10 is painted, but only the lower portion of the inclined portion 10 is painted glossy, and the remaining portion is painted matte. Therefore, as shown in FIG. 4C , the glossy portion 20 is formed only on the lower portion of the surface of the inclined portion 10, and the portion above the glossy portion 20 is formed as a matte surface 21. Therefore, the lower portion of the inclined portion 10 appears brighter due to the glossy portion 20 and darker due to the matte surface 21. Therefore, the lower portion of the inclined portion 10 appears to be located closer to the front (forward) than the upper portion. Therefore, the inclination of the inclined portion 10 appears to be more pronounced than the actual inclination angle D (the inclination angle appears to be greater than the actual inclination angle D). As a result, the wall panel 100 provides a sense of depth (three-dimensionality or perspective) relative to its thickness.

[0051] The vertical dimension of the glossy portion 20 can be, for example, 10 mm, but is not limited to this.

[0052] (Embodiment 4) The wall panel 100 according to this embodiment differs from the wall panels 100 according to the first to third embodiments in the configuration of the inclined portion 10.

[0053] Hereinafter, the same components as those in the first to third embodiments will be denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0054] The configuration described in the fourth embodiment can be applied in appropriate combination with the configurations (including modified examples) described in the first to third embodiments.

[0055] As shown in FIG. 4D , the wall panel 100 of this embodiment has a streak pattern 13 formed on the surface of the inclined portion 10. The streak pattern 13 is composed of multiple vertical stripes 12 extending vertically along the inclination direction of the inclined portion 10. The multiple vertical stripes 12 are arranged side by side in the left-right direction. Each vertical strip 12 tapers upward along the inclination direction of the inclined portion 10. That is, each vertical strip 12 is formed so that its width (horizontal dimension) is largest at its lower end and gradually decreases toward its upper end. Therefore, each vertical strip 12 tapers gradually from the front (lower part) of the inclined portion 10 toward the back (upper part). As a result, the lower part of the inclined portion 10 appears to be located closer to the front (forward) side than the upper part. Therefore, the inclination of the inclined portion 10 appears to be more pronounced than the actual inclination angle D (the inclination angle appears to be greater than the actual inclination angle D). As a result, the wall panel 100 provides a sense of depth (three-dimensionality or perspective) relative to its thickness.

[0056] Each vertical stripe 12 can be formed by painting, such as inkjet painting. Alternatively, each vertical stripe 12 can be formed by a groove. In this case, the groove can be varied in depth in addition to varying its width. That is, the vertical stripes 12 formed by the grooves become shallower from bottom to top along the inclination direction of the inclined portion 10.

[0057] (summary) The first aspect is a wall panel 100 having at least one inclined portion 10 on its surface. The inclined portion 10 extends in the left-right direction and is inclined forward from top to bottom. An uneven pattern 11 is formed on the surface of the inclined portion 10. The uneven pattern 11 is formed so that it becomes shallower from bottom to top.

[0058] According to this embodiment, in a front view, the shadows cast by the uneven pattern 11 become stronger toward the front (lower part) of the inclined portion 10, and the shadows cast by the uneven pattern 11 become vague toward the back (upper part), so that the upper part appears to be positioned further back. Therefore, a sense of depth is obtained in comparison with the plate thickness.

[0059] The second embodiment is the wall panel 100 of the first embodiment, in which the uneven pattern 11 becomes smaller in size from bottom to top when the inclined portion 10 is viewed from the front.

[0060] According to this embodiment, the ambiguity of the shadows created by the uneven pattern 11 is emphasized toward the back (upper portion) of the inclined portion 10, and the sense of depth is strengthened.

[0061] The third embodiment is the wall panel 100 of the first or second embodiment, in which the inclined portion 10 is colored, and the color becomes darker from bottom to top.

[0062] According to this embodiment, the shadows created by the uneven pattern 11 are emphasized toward the back (upper portion), and the sense of depth is strengthened.

[0063] The fourth aspect is a wall panel 100 according to any one of the first to third aspects, in which the inclined portion 10 is formed with a stripe pattern 13 in which a plurality of vertical stripes 12 extending in the up-down direction are aligned in the left-right direction, and each of the vertical stripes 12 becomes thinner as it goes from bottom to top.

[0064] According to this embodiment, the vertical stripes 12 become vague from the front side (lower part) of the inclined portion 10 to the back side (upper part), thereby enhancing the sense of depth.

[0065] The fifth aspect is the wall panel 100 of any one of the first to fourth aspects, in which a plurality of inclined portions 10 are formed in the vertical direction, and the inclination directions of the plurality of inclined portions 10 are parallel to each other.

[0066] According to this aspect, the armor-like wall panel emphasizes the sense of depth rather than the actual thickness of the panel. [Explanation of symbols]

[0067] 100 wallboard 10 Slope 11 Textured pattern 12 Vertical Stripes

Claims

1. A wallboard having at least one slope on a surface, the inclined portion extends in the left-right direction and inclines forward from top to bottom, and has an uneven pattern formed on its surface; The uneven pattern is formed so as to become shallower from the bottom to the top. wall board.

2. When the inclined portion is viewed from the front, the uneven pattern becomes smaller in size from bottom to top. The wallboard of claim 1.

3. The inclined portion is colored, and the color becomes darker from bottom to top.

3. A wallboard according to claim 1 or 2.

4. The inclined portion has a stripe pattern formed thereon in which a plurality of vertical stripes extending in the up-down direction are aligned in the left-right direction, Each of the plurality of vertical stripes becomes thinner from bottom to top.

3. A wallboard according to claim 1 or 2.

5. A plurality of the inclined portions are formed in the vertical direction, The inclination directions of the plurality of inclined portions are parallel to each other.

3. A wallboard according to claim 1 or 2.

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