Slats and blinds

Abstract

To provide slats and blinds with a shape that can improve shading performance when fully closed without significantly altering the design of conventional slats. [Solution] The slats 120 are tiltably supported by a ladder cord 130 and are used in a blind 100 in which, in the fully closed state, the lower slat 120 and the adjacent upper slat 120 overlap in the front-rear direction to form an overlapping region DA. The slats have a width W and a height H in the short direction, and their shape is asymmetrical from the center in the short direction. In the overlapping region DA, the distance between the lower slat 120 and the lower end of the upper slat 120 is narrower or nonexistent than that of a symmetrical slat with a width W and height H in the short direction and a symmetrical arc shape from the center in the short direction. Therefore, it is possible to improve the shielding performance in the fully closed state without significantly changing the design of conventional slats.

Description

Technical Field

[0001] The present invention relates to slats and blinds.

Background Art

[0002] As conventional slats and blinds, those shown in U.S. Patent No. 6,167,938 (Patent Document 1) are known. The slats disclosed in this Patent Document 1 are asymmetric slats having short pieces and long pieces, and the angle of the vertex connecting the short piece and the long piece is 130° to 170°, and the lifting cord insertion holes are formed at positions 18 to 26% from the longitudinal edge of the short piece and 25 to 50% from the transverse edge of the short piece.

[0003] According to such a configuration, when the slats rotate until the long piece of the upper slat abuts on the short piece of the lower slat, the long piece is vertically arranged, so that the shielding property in the fully closed state can be improved.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, the slats of the above Patent Document 1 have a shape in which the vertex connecting the short piece and the long piece protrudes, and since the design is significantly different from the conventionally most commonly used curved slats, it may not be possible to say that it is suitable for replacing the conventional slats in terms of design. Therefore, there has been a demand for slats having a shape capable of improving the shielding property in the fully closed state without significantly changing the design of the conventional slats.

[0006] Therefore, the present invention has been made in view of these problems, and its objective is to provide a slat and blind with a shape that can improve the shielding performance in the fully closed state without significantly changing the design of conventional slats. [Means for solving the problem]

[0007] To solve the above problems, according to a first aspect of the present invention, a slat is provided for use in a blind that is tiltably supported by a ladder cord and, in a fully closed state, forms an overlapping region in which a lower slat and an adjacent upper slat overlap in the front-rear direction, wherein the slat width in the short direction is W, the slat height is H, the shape from the center in the short direction to the left and right is asymmetrical, and the distance between the lower slat and the lower end of the upper slat in the overlapping region is narrower than or nonexistent than that of a symmetrical slat with a slat width in the short direction W, a slat height H, and a symmetrical arc shape from the center in the short direction to the left and right.

[0008] A more specific configuration may include, for example, a first piece having a first width in the shorter direction and forming a slat height region, a second piece having a second width shorter than the first width in the shorter direction and curving or inclining from one end of the first piece, and a third piece having a third width longer than the second width in the shorter direction and curving or inclining from the other end of the first piece, wherein in the fully closed state, the second piece may be arranged to face the third piece of the adjacent upper slat on the convex side.

[0009] With this configuration, the slats have a design similar to conventional slats, but asymmetrical in the shorter direction. Therefore, it is possible to improve the shielding performance in the fully closed state without significantly altering the design of conventional slats. Furthermore, because the gap between the lower slat and the lower end of the upper slat is narrow or nonexistent in the overlapping area, reflected light (including mutual reflection) on the slat surface is reduced, improving the shielding performance between slats in the fully closed state. In this way, it is possible to improve the shielding performance in the fully closed state with slats that have a design that does not feel out of place even when used as a replacement for conventional slats.

[0010] Furthermore, according to a second aspect of the present invention, a slat is provided that has a first piece having a first width in the short direction and forming a slat height region, a second piece having a second width shorter than the first width in the short direction and curving or inclining from one end of the first piece, and a third piece having a third width longer than the second width in the short direction and curving or inclining from the other end of the first piece, wherein in a fully closed state, the second piece is arranged to face the third piece of the adjacent upper slat on the convex side.

[0011] With this configuration, the shielding performance in the fully closed state can be improved by using slats with a design similar to that of conventional slats, but with an asymmetrical shape in the short-side direction. Specifically, by using slats with an asymmetrical shape in which the first piece forming the arrow height region is biased to one side in the short-side direction, the gap between slats in the fully closed state can be reduced, thereby improving shielding performance. In addition, because the gap between the blind surface (a virtual surface along the vertical cord of the ladder cord) and the slat surface is reduced, reflected light (including mutual reflection) on the slat surface can be reduced, improving the shielding performance between slats in the fully closed state. In this way, the shielding performance in the fully closed state can be improved with slats that have a design that does not feel out of place even when used as a replacement for conventional slats.

[0012] The present invention has various applications. For example, the second piece may be positioned in an overlapping region where the slat and the upper slat overlap in the front-to-back direction when the slat is fully closed. With this configuration, the gap between the slats in the fully closed state becomes smaller, thus improving the shielding performance in the fully closed state.

[0013] Furthermore, the first piece may extend to the overlapping region in the fully closed state. With this configuration, the gap with the upper slat can be narrowed in the overlapping region, thereby further improving shielding performance.

[0014] Furthermore, the relationship between the slat width and the arrow height in the arrow height region may be set to satisfy the relationship between slat width and arrow height as defined in "JIS A 4801". With this configuration, it is possible to improve the shading performance in the fully closed state while maintaining the same level of visibility as conventional slats conforming to JIS standards. In addition, the slats of the present invention can be installed in blinds equipped with conventional slats conforming to JIS standards without changing the specifications.

[0015] Furthermore, according to a third aspect of the present invention, a blind is provided that is characterized by comprising the slats according to the first or second aspect of the present invention.

[0016] With this configuration, it is possible to create a blind that can improve the shielding performance when fully closed without significantly altering the design of the conventional slats.

[0017] In the blind of the present invention, for example, a lifting cord may be further provided through which the slats are inserted such that adjacent slats in the vertical direction do not come into contact with each other when the blind is fully closed. This configuration is particularly advantageous in blinds where gaps may occur between the slats when the blind is fully closed. [Effects of the Invention]

[0018] According to the slats and blinds of the present invention, it is possible to improve the shielding performance in the fully closed state without significantly altering the design of conventional slats. Other effects of the present invention will be explained in the embodiments for carrying out the invention described later. [Brief explanation of the drawing]

[0019] [Figure 1] This is a front view showing the overall configuration of the blind 100 in this embodiment. [Figure 2] This is a side view showing the shape of the slat, where (a) shows the slat 120 of this embodiment and (b) shows the slat 320 of a conventional specification. [Figure 3] It is a diagram showing the dimensions and shape of the slats defined by "JIS A 4801", where (a) shows the dimensions and (b) shows the shape. [Figure 4] It is a side view showing the state of the slats supported by the ladder cord 130, where (a) shows the slats 120 of the present embodiment, (b) shows the slats 320 of the conventional specification, and (c) shows the state where the slats 120 and the slats 320 of the conventional specification are superimposed. [Figure 5] It is a diagram showing the fully closed state, where (a) shows the slats 120 of the present embodiment, (b) shows the slats 320 of the conventional specification, and (c) shows the state where the slats 120 and the slats 320 of the conventional specification are superimposed. [Figure 6] It is a diagram showing the conditions of the luminance distribution simulation of the blind 100 of the present embodiment and the blind 300 of the conventional specification. [Figure 7] It is a diagram showing the comparison of the luminance distribution by simulation, where (a) is a front view using the blind 100 of the present embodiment, (b) is a perspective view using the blind 100 of the present embodiment, (c) is a front view using the blind 300 of the conventional specification, and (d) is a perspective view using the blind 300 of the conventional specification. [Figure 8] It is a side view showing the superimposed slats 220 of the modified example and the slats 320 of the conventional specification, where (a) shows the horizontal state and (b) shows the fully closed state.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations are omitted.

[0021] The overall configuration of the blind 100 according to the present embodiment will be described with reference to FIG. 1. FIG. 1 is a front view showing the overall configuration of the blind 100 of the present embodiment. In the following description, the slat width is the width in the short side direction of the slats.

[0022] As shown in Figure 1, the blind 100 of this embodiment comprises a headbox 110, a plurality of slats 120 suspended and supported from the headbox 110 so as to be able to move up and down, a ladder cord 130 that tilts and suspends the plurality of slats 120, a lifting cord 140 that moves up and down through elongated holes formed in the plurality of slats 120, and a bottom rail 150 positioned below the lowest slat 120, to which the lower ends of the ladder cord 130 and the lifting cord 140 are connected.

[0023] As shown in Figure 1, the headbox 110 is attached to a window frame or the like (not shown) by a bracket 112. An operating cord 160 for controlling the tilting and raising / lowering of the slats 120 hangs down from one end of the headbox 110. Inside the headbox 110, a drum 170 is rotatably arranged to which the upper ends of the ladder cord 130 and the lifting cord 140 are connected so as to be able to be wound up and unwound. The rotation of the drum 170 is controlled by the operating cord 160. The rotation of the drum 170 controls the tilting of the ladder cord 130 and the raising and lowering of the lifting cord 140. The configuration of the blind 100, other than the shape of the slats 120, can be configured in the same way as a general blind.

[0024] The overall configuration of the blind 100 has been described above. Below, the slats 120, which are a characteristic feature of this embodiment, will be described with reference to Figures 2 and 3. Figure 2 is a side view showing the shape of the slats, where (a) shows the slats 120 of this embodiment and (b) shows the slats 320 of a conventional specification. Figure 3 is a diagram showing the dimensions and shape of the slats as defined in "JIS A 4801", where (a) shows the dimensions and (b) shows the shape.

[0025] As shown in Figure 2(a), the slat 120 is configured with a slat width W and a slat height H. The slat 120 is composed of a continuous first piece 122, a second piece 124, and a third piece 126, and the slat width W is the sum of the widths of these three pieces. The first piece 122 has a first width W1 in the short direction and forms a slat height region of height H across its entire surface. The second piece 124 has a second width W2 that is shorter than the first width W1 in the short direction and curves downward from one end of the first piece 122 to a height of slat height H. The third piece 126 has a third width W3 that is longer than the second width W2 in the short direction and curves downward from the other end of the first piece 122 to a height of slat height H. As shown in Figure 5, which will be described later, in the fully closed state, the second piece 124 is positioned in the overlapping region DA such that it faces the third piece 126 of the adjacent upper slat 120 on the convex side. Slat 120 has a slat width W and a slat height H as defined in "JIS A 4801" as shown in Figure 3 below.

[0026] As shown in Figure 2(a), the first piece 122 is a flat plate-like structure that extends across its entire surface. The second piece 124 is curved in an arc shape connecting the arrow height H and the second width W2. In this embodiment, the arrow height H and the second width W2 are configured to be approximately the same size. The third piece 126 is configured in a gently curved shape. The elongated hole through which the lifting cord 140 is inserted may be provided only in the first piece 122, or it may extend from the first piece 122 to the third piece 126, or it may extend from the first piece 122 to the second piece 124.

[0027] As shown in Figure 2(b), the conventional slat 320 has the same slat width W and slat height H as the slat 120, and its front and rear shapes are symmetrical and bow-shaped.

[0028] Here, we will explain the dimensions and shape of the slats as defined in "JIS A 4801," referring to Figure 3. The dimensions of each slat are defined as follows, as shown in Figure 3(a). The unit is mm. • A slat designated as 50 has a slat width W of 50.0 and a slat height H of 5.0 ± 1.0. • Slats designated as 35 have a slat width W of 35.0 and a slat height H of 3.8 ± 1.0. • Slats designated as 28 have a slat width W of 28.0 and a slat height H of 2.5 ± 0.5. • Slats designated as No. 25 have a slat width W of 25.0 and a slat height H of 2.2 ± 0.5. • Slats designated as 18 have a slat width W of 18.0 and a slat height H of 1.5 ± 0.5. • Slats designated as 15 have a slat width W of 15.0 and a slat height H of 1.2 ± 0.5. The thickness t of the slat base plate is 0.10 or more for both aluminum alloy and steel.

[0029] The shape of the slats is symmetrical in the direction of the slat width W, as shown in Figure 3(b). The slats are arched (circular arc), trapezoidal, or V-shaped, with the same dimensions for slat width W and slat height H. The shape of arched and V-shaped slats is uniquely determined by the slat width W and slat height H. The width of the slat product is selected from a range of ±2.0 mm relative to the slat width W. The manufacturing tolerance for the slat product is ±0.5 mm for width and ±0.07 mm for thickness.

[0030] The configuration of the slat 120 has been described above. The operation of the slat 120 will now be described with reference to Figures 4 and 5. Figure 4 is a side view showing the state of the slat supported by the ladder cord 130, where (a) shows the slat 120 of this embodiment, (b) shows the conventional slat 320, and (c) shows the state in which the slat 120 and the conventional slat 320 are superimposed. Figure 5 is a diagram showing the fully closed state, where (a) shows the slat 120 of this embodiment, (b) shows the conventional slat 320, and (c) shows the state in which the slat 120 and the conventional slat 320 are superimposed.

[0031] The slat 120 in its fully open state, where the slat is almost horizontal, and the conventional slat 320 will be explained with reference to Figure 4. As shown in Figure 4(a), the slat 120 is supported by a middle cord 134 that is provided across a pair of front and rear vertical cords 132 that make up the ladder cord 130, with the second piece 124 positioned on the interior side and the third piece 126 on the window side. When viewed from the side, the slat 120 has a shape where the interior side is raised. On the other hand, the conventional slat 320 has a symmetrical shape in the front-to-back direction, as shown in Figure 4(b).

[0032] As shown in Figure 4(c), when slat 120 is superimposed on conventional slat 320, the interior side of the slat width is raised higher than that of conventional slat 320, while the window side is the same as that of conventional slat 320. Thus, when fully open, slat 120 has the same height H as conventional slat 320, so the design does not differ significantly from blinds using conventional slat 320, and a similar level of view can be secured.

[0033] Next, the state of the slat 120 in the fully closed state, which is the state in which the slat is tilted the most, and the state of the conventional slat 320 will be explained with reference to Figure 5. In the fully closed state, the slat 120 is tilted so that the second piece 124 is positioned above and the third piece 126 is positioned below, as shown in Figure 5(a). The upper ends of the second piece 124 and the first piece 122 of the lower slat 120 are positioned in an overlapping region DA where they overlap and face the convex side of the third piece 126 of the adjacent upper slat 120. In this embodiment, the blind 100 has a configuration in which the lifting cord 140 is inserted through the slat 120, so a gap is created between the upper and lower slats 120 in the fully closed state. Since the arrow height region of the slat 120 is positioned in the overlapping region DA, the distance F between the lower end of the first piece 122 of the lower slat 120 and the lower end of the third piece 126 of the upper slat 120 is narrow in the overlapping region DA. Therefore, reflected light, including mutual reflection between the upper and lower slats 120, is reduced, and the amount of light entering the room can be suppressed.

[0034] Next, we will describe the non-overlapping region NDA formed between the surface of the lower slat 120 and the blind surface BS, which is a virtual surface along the vertical code 132 of the ladder code 130, from the position where the lower slat 120 abuts the vertical code 132 to the overlapping region DA. In the non-overlapping region NDA, the first piece 122 is positioned over almost its entirety. Therefore, the surface of the slat 120 in the non-overlapping region NDA becomes a planar arrow height region. Since the arrow height region is the part of the slat 120 that protrudes the most, the inclination from the blind surface BS becomes small. Thus, throughout almost the entire non-overlapping region NDA, the slat 120 receives sunlight at an inclination angle close to that of the window surface, even above the slat. Therefore, the amount of light reflected in the non-overlapping region NDA that is directed toward the concave surface of the upper slat 120 is reduced, the amount of reflected light including mutual reflection between the upper and lower slats 120 is reduced, and the amount of sunlight that penetrates into the room is reduced.

[0035] In contrast, with conventional slats 320, as shown in Figures 5(b) and (c), the upper part of the conventional slats 320 is curved inward compared to the slats 120. Therefore, the spacing G between the upper and lower conventional slats 320 in the overlapping area DA is wider than the spacing F, resulting in more sunlight entering the room. Also, in the non-overlapping area NDA, the conventional slats 320 are curved inward, resulting in a greater inclination from the blind surface BS. Therefore, in the non-overlapping area NDA, the conventional slats 320 receive sunlight at an angle of inclination that is further from the window surface as the slats rise. As a result, a larger amount of light reflected in the non-overlapping area NDA is directed towards the concave surface of the upper slat 120, resulting in more reflected light, including mutual reflection between the upper and lower conventional slats 320, and more sunlight entering the room.

[0036] The luminance distribution of the blind 100 using the slats 120 of this embodiment and the blind 300 using the conventional slats 320 will be explained by referring to Figures 6 and 7. Figure 6 is a diagram showing the conditions for the luminance distribution simulation of the blind 100 of this embodiment and the conventional blind 300. Figure 7 is a diagram showing a comparison of the luminance distribution by simulation, where (a) is a front view of the present invention, (b) is a perspective view of the present invention, (c) is a front view of the conventional specification, and (d) is a perspective view of the conventional specification.

[0037] The simulation is performed by hanging the blind 100 of this embodiment and the conventional blind 300 from the window of a room. As shown in Figure 6, the room has a depth and width of 3000 mm and a height of 2800 mm, with an opening M in one of the walls that is 2000 mm high and wide. The simulation is performed by hanging the blind 100 of this embodiment and the conventional blind 300 from the opening M in the room. Although there is no window in the opening M in the simulation, for the sake of explanation, the opening M will be referred to as the window surface. Other conditions are as follows. external conditions Date: Winter Solstice Time: Noon Weather: Clear skies Optical properties (material: reflectance) Ceiling: 70% Walls: 50% Floor: 10% Slats: 70%

[0038] As shown in Figure 7, the simulation results of the luminance distribution in area A of the window surface and area B of the wall surface, where blinds 100 or 300 are placed, are as follows.

[0039] <Simulation Results> Average brightness of the window surface (area A) Blind 100 of this embodiment: 639 [cd / m2] Conventional blind specifications 300: 917 [cd / m2] Therefore, the blind 100 of this embodiment can reduce the average brightness of the window surface by 30.3% compared to the conventional blind 300.

[0040] Average wall surface brightness (area B) Blind 100 of this embodiment: 73 [cd / m2] Conventional blind specifications: 300:108 [cd / m2] Therefore, the blind 100 of this embodiment can reduce the average wall surface brightness by 32.4% compared to the conventional blind 300.

[0041] (Effects of this embodiment) As described above, according to this embodiment, the shielding performance in the fully closed state can be improved by using a slat 120 with a design similar to that of a conventional slat 320, but with an asymmetrical shape in the short-side direction (i.e., the shape of the left and right sides from the center in the short-side direction is asymmetrical).

[0042] Furthermore, since the Slat 120 has the same height (H) as the conventional Slat 320, when fully open, its design does not differ significantly from blinds using the conventional Slat 320, and it can provide a similar level of view.

[0043] Furthermore, by making the slat 120 an asymmetrical shape in which the first piece 122 forming the arrow height region is biased to one side in the shorter direction, the gap between the upper and lower slats 120 in the fully closed state can be reduced, thereby improving shielding performance.

[0044] Furthermore, because the gap between the blind surface BS and the slat surface 120 is reduced, reflected light (including mutual reflection) from the slat surface can be reduced, improving the shielding performance between the upper and lower slats 120 when the blind is fully closed.

[0045] Furthermore, the slat 120 has a design that does not look out of place even when used as a replacement for the conventional slat 320, and it can improve shielding performance when fully closed.

[0046] Since the second piece 124 is positioned in the overlapping region DA where the lower slat 120 and the upper slat 120 overlap in the front-to-back direction when fully closed, the gap between the upper and lower slats 120 in the fully closed state becomes smaller. Therefore, the shielding performance in the fully closed state can be further improved.

[0047] Furthermore, since the first piece 122 extends to the overlapping region DA when fully closed, the gap between it and the upper slat 120 in the overlapping region DA can be narrowed. Therefore, shielding performance can be further improved.

[0048] The relationship between the slat width W, which is the sum of the first width W1, the second width W2, and the third width W3, and the arrow height H in the arrow height region satisfies the relationship between slat width and arrow height as defined in "JIS A 4801". Therefore, it is possible to improve the shading performance in the fully closed state while maintaining the same level of visibility as conventional slat 320 conforming to JIS standards. Furthermore, the slat 120 of the present invention can be installed in a blind 300 equipped with conventional slat 320 conforming to JIS standards without changing the specifications.

[0049] Furthermore, this design is particularly advantageous for blinds 100 in which, when fully closed, the upper and lower slats 120 may not completely close, resulting in a gap.

[0050] (modified version) A modified example of the slat 120 of this embodiment will be described with reference to Figure 8. Figure 8 is a side view showing a modified example, where (a) shows the modified slat 220 and (b) shows the conventional slat 320. As shown in Figure 8(a), the third piece 226 of the slat 220 is curved downward in the opposite direction to the curvature direction of the conventional slat 320. In the fully closed state, as shown in Figure 8(b), the third piece 226 is closer to the first piece 222 and the second piece 224 of the adjacent lower slat 220 compared to the conventional slat 320. Therefore, the shielding performance in the fully closed state can be improved.

[0051] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to these examples. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention.

[0052] For example, in the above embodiment, the slat 120 is configured with a first piece 122, a second piece 124, and a third piece 126, but the present invention is not limited to this example. It can be designed arbitrarily as long as the shape on the left and right sides is asymmetrical from the center in the short direction. For example, it may be composed of two pieces, or four or more pieces.

[0053] Furthermore, although the second piece 124 and the third piece 126 are configured in a curved shape in the above embodiment, the present invention is not limited to this example. It can be designed arbitrarily as long as it is possible to improve the shielding performance in the fully closed state without significantly changing the design of the conventional slats. For example, the second piece 124 may have a gentle curve or inclination. The third piece 126 may have a curve or inclination with a large curvature.

[0054] Furthermore, in the above embodiment, the entire width of the first piece 122 is defined as the slat height region, but the present invention is not limited to this example. It can be designed arbitrarily as long as it is possible to improve the shielding performance in the fully closed state without significantly changing the design of conventional slats. For example, the slat height region of the first piece may be a part of the first width.

[0055] Furthermore, in the above embodiment, an elongated hole is formed in the slat 120 through which the lifting cord 140 is inserted, but the present invention is not limited to this example. It can be designed arbitrarily as long as it is possible to improve the shielding performance in the fully closed state without significantly changing the design of the conventional slat. For example, the slat may be made without holes, and the lifting cord may be suspended along the front and rear edges of the slat, or the hole through which the lifting cord 140 is inserted may be formed as a short hole in the second piece 124.

[0056] Furthermore, in the above embodiment, the first piece 122 is configured to extend to the overlapping region DA in the fully closed state, but the present invention is not limited to this example. It can be designed arbitrarily as long as it is possible to improve the shielding performance in the fully closed state without significantly changing the design of the conventional slats. For example, only the second piece may be placed in the overlapping region.

[0057] Furthermore, in the first embodiment described above, the relationship between the slat width and the arrow height in the arrow height region was configured to satisfy the relationship between slat width and arrow height as defined in "JIS A 4801," but the present invention is not limited to this example. It can be designed arbitrarily as long as it is possible to improve the shielding performance in the fully closed state without significantly changing the design of the conventional slats. [Explanation of symbols]

[0058] 100, 300 blinds 110 Headbox 112 bracket 120, 220 slats 122, 222 1st piece 124, 224 2nd piece 126, 226 3rd piece 130 Ladder Code 132 Vertical Code 134 Middle section code 140 Lifting cord 150 Bottom Rail 160 Operation Codes 170 drums 320 Conventional slats H Yataka W Slat width W1 1st width W2, 2nd width W3 3rd width DA overlap area NDA non-overlapping area BS blind surface M Window

Claims

1. A slat used in a blind, which is tiltably supported by a ladder cord and, in the fully closed state, forms an overlapping region where the lower slat and the adjacent upper slat overlap in the front-to-back direction, The slat width in the shorter direction is W, the slat height is H, and the shape from the center in the shorter direction to the left and right is asymmetrical. A slat characterized in that, in the overlapping region, the distance between the lower slat and the lower end of the upper slat is narrower than or absent than that of a symmetrical slat with a slat width W in the short direction, a slat height H, and a circular arc shape that is symmetrical from the center in the short direction.

2. A first piece having a first width in the shorter direction and forming a yaw height region, The second piece has a second width shorter than the first width in the shorter direction, and is curved or inclined from one end of the first piece, The third piece has a third width that is longer than the second width in the shorter direction, and is curved or inclined from the other end of the first piece, The slat according to claim 1, characterized in that, in the fully closed state, the second piece is arranged to face the third piece of the adjacent upper slat on the convex side.

3. A first piece having a first width in the shorter direction and forming a yaw height region, The second piece has a second width shorter than the first width in the shorter direction, and is curved or inclined from one end of the first piece, The third piece has a third width that is longer than the second width in the shorter direction, and is curved or inclined from the other end of the first piece, A slat characterized in that, when fully closed, the second piece is arranged to face the third piece of an adjacent upper slat on its convex side.

4. The slat according to claim 3, characterized in that the second piece is positioned in an overlapping region where the slat and the upper slat overlap in the front-rear direction when the slat is fully closed.

5. The slat according to claim 4, characterized in that the first piece extends to the overlapping region in the fully closed state.

6. The slat according to claim 2, characterized in that the relationship between the slat width and the arrow height in the arrow height region satisfies the relationship between slat width and arrow height as defined in "JIS A 4801".

7. A blind characterized by comprising the slats described in any one of claims 1 to 6.

8. The blind according to claim 7, further comprising a lifting cord through which the slats are inserted such that adjacent slats in the fully closed state do not come into contact with each other.

Images