JP2016132886A - Manufacturing method for opening structure with daylighting function, manufacturing method for daylighting member, and method for discerning orientation of daylighting member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain desired daylighting performance, by readily discerning orientation of a daylighting member and installing, or enabling installation of, the daylighting member in a proper orientation.SOLUTION: A method of the present invention includes: a preparation step in which laminated glass 10 is prepared that includes a light deflection element 22 for totally reflecting light incident on a front surface 10A from a direction inclined upward by an angle within a design angular range Ra, when top, bottom, front, and rear sides of the laminated glass are positioned in a prescribed orientation, and the light totally reflected by the light deflection element 22 is emitted from a rear surface 10B; and an orientation discerning step in which orientation of at least one of the top, bottom, front, or rear sides of the laminated glass 10 is discerned. In the orientation discerning step, orientation of at least one of the top, bottom, front, or rear sides of the laminated glass 10 is discerned based on light emitted from the laminated glass 10 after having test light Lt input into the laminated glass 10 from a direction inclined by a prescribed angle θt within the design angular range Ra.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing an opening structure with a lighting function, a method for manufacturing a daylighting member, and a method for determining the direction of a daylighting member for daylighting outside light such as sunlight into a room with a desired daylighting performance.

  2. Description of the Related Art Conventionally, a daylighting member for deflecting outside light such as sunlight and daylighting indoors is known. As such a daylighting member, a daylighting sheet formed in a sheet shape, a laminated glass formed by arranging a daylighting sheet between two sheets of glass, a daylighting blind whose slat part has a daylighting function, a roll screen shape And a daylighting roll screen formed in the above. For example, a daylighting sheet is used by being attached to a window glass or the like of a building, and a laminated glass, a daylighting blind, or a daylighting roll screen is used by being installed in an opening of a building or the like. Such a daylighting member can, for example, lighten the entire room by deflecting the incident outside light toward the ceiling of the room and emitting it, compared to simply allowing the outside light to pass through the room. it can.

  Patent Document 1 discloses this type of daylighting sheet. This daylighting sheet includes a sheet-like base material layer having translucency and a light deflection layer for deflecting light. The light deflection layer includes a plurality of light transmission portions arranged side by side along one surface of the base material layer, and a material having a refractive index lower than that of the light transmission portion and disposed between the plurality of light transmission portions. And an optical deflection unit.

  The daylighting sheet concerning this patent document 1 can be used in the state where it was stuck on the window glass etc. of a building along the up-and-down direction. In such a use state, the side on the upper side of the light deflection unit is formed to have a polygonal line shape or the like that protrudes downward in a cross section in the thickness direction. With such a shape, external light can be deflected and emitted toward the indoor ceiling.

  Further, Patent Document 2 discloses a daylighting sheet having a light deflection section formed of a prism formed asymmetrically with respect to the normal direction of the sheet surface. In this daylighting sheet, since sunlight is incident on the upper surface side of the prism, the shape of the upper surface is optimized so that most of the light incident on the upper surface side is reflected obliquely upward in the room.

  In the daylighting sheets disclosed in Patent Literature 1 and Patent Literature 2, the light deflection section is formed asymmetrically with respect to the normal direction of the sheet surface. On the other hand, a daylighting sheet having a light deflection section formed symmetrically with respect to the normal direction of the sheet surface is also known.

Japanese Patent Application Laid-Open No. 2014-119738 Special table 2013-514549 gazette

  If a daylighting member in which the light deflection part is formed asymmetrically with respect to the normal direction of the sheet surface is used upside down or front and back, the desired daylighting performance cannot be obtained. On the other hand, in the daylighting member in which the light deflection part is formed symmetrically with respect to the normal direction of the sheet surface, if the front and back surfaces are correctly arranged, it may be used properly even if the up and down directions are wrong. . However, if the front and back surfaces are used incorrectly, the desired lighting performance cannot be obtained.

  Therefore, when using such a daylighting member, it is necessary to accurately grasp its direction. However, the light deflection unit is usually a small size and is transparent. Therefore, the upper and lower sides and the front and back cannot be easily determined by visual confirmation of the appearance. As a result, a situation in which a desired lighting performance cannot be obtained can occur by using the wrong direction. And the problem that the correction will take time will arise. For example, when a laminated glass having a daylighting sheet is configured by improperly arranging the daylighting sheets between the glasses, it takes a lot of time to correct it, leading to a decrease in yield in the manufacturing process.

  As a measure for recognizing the direction of the daylighting member, it is conceivable to provide an index indicating the direction of the daylighting member in the manufacturing stage. However, there is a possibility that such an index is arranged at a position where it can be seen even after the lighting member is installed. Therefore, this measure is not always preferable in view of the appearance.

  The present invention has been made in view of the above circumstances, and the desired lighting performance can be obtained by easily determining the direction of the daylighting member and installing or allowing the daylighting member to be installed in the correct direction. It aims at providing the manufacturing method of the aperture structure with a lighting function, the manufacturing method of a lighting member, and the direction discrimination method of a lighting member.

  In order to solve the above-described problems, the present invention provides a light deflection element that totally reflects light incident on a surface from a direction inclined upward at an angle within a design angle range in a state where the upper and lower sides and the front and back sides are arranged in a specified direction. A preparation step of preparing a daylighting member for emitting light totally reflected by the light deflection element from the back surface, a direction discrimination step for discriminating at least one of upper and lower sides and front and back of the daylighting member, and the direction discrimination An installation step of installing the daylighting member in an opening formed in the structure based on the determination result of the step to configure an opening structure with a daylighting function, and in the direction determination step, within the design angle range The test light is incident on the daylighting member from a direction inclined at a predetermined angle of at least one of the upper and lower sides and the front and back sides of the daylighting member based on the outgoing light emitted from the daylighting member. Determine, to provide a method for manufacturing a lighting function open structure.

  The predetermined angle is such that when light is incident on the back surface from a direction inclined upward in a state where the front and back of the daylighting member are arranged opposite to the prescribed direction, the light is deflected by the light deflection element. It is preferable that the angle is set so as not to totally reflect.

  The predetermined angle is determined when the light is incident on the surface from a direction inclined upward in a state where the upper and lower sides of the daylighting member are arranged opposite to the prescribed direction. It is preferable that the angle is set so as not to be totally reflected by the element.

  The daylighting member includes a base formed in a sheet shape and a plurality of the light deflection elements arranged in a sheet surface direction of the base, and the light deflection element has a lower refractive index than the base. The upper surface of the light deflection element is formed in the shape of a polygonal line or a curve projecting downward in a longitudinal section along the thickness direction of the daylighting member, and the upper surface is formed of the base portion. The angle formed with respect to the normal line direction may be larger on the front side than on the back side.

  Here, when the upper side surface of the light deflection element is formed in a polygonal line in a longitudinal section along the thickness direction of the daylighting member, the predetermined angle is such that the upper and lower sides and the front and back of the daylighting member are in the specified direction. When the light is incident on the surface from a direction inclined upward, the angle formed by the traveling direction of the light with respect to the normal direction is the surface side of the upper side surface. It is preferable that the plane portion closest to is set to be larger than an angle formed with respect to the normal direction.

  Further, the predetermined angle is such that when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides and the front and back of the daylighting member are arranged in the prescribed direction, the light is incident on the upper side surface. It is preferable to set so that it may enter only into the plane part nearest to the said surface side.

  The present invention also includes a light deflection element that totally reflects light incident on the surface from a direction inclined upward at an angle within a design angle range in a state where the upper and lower sides and the front and back sides are arranged in a prescribed direction, Based on a preparation step of preparing a daylighting member that emits light totally reflected by the element from the back surface, a direction discrimination step that discriminates at least one of upper and lower sides and front and back of the daylighting member, and a discrimination result of the direction discrimination step A step of processing the daylighting member, and in the direction determining step, test light is incident on the daylighting member from a direction inclined at a predetermined angle within the design angle range, and from the daylighting member. Provided is a daylighting member manufacturing method for discriminating at least one of the upper and lower sides and the front and back sides of the daylighting member based on the emitted light.

  The predetermined angle is such that when light is incident on the back surface from a direction inclined upward in a state where the front and back of the daylighting member are arranged opposite to the prescribed direction, the light is deflected by the light deflection element. It is preferable that the angle is set so as not to totally reflect.

  The predetermined angle is determined when the light is incident on the surface from a direction inclined upward in a state where the upper and lower sides of the daylighting member are arranged opposite to the prescribed direction. It is preferable that the angle is set so as not to be totally reflected by the element.

  The daylighting member includes a base formed in a sheet shape and a plurality of the light deflection elements arranged in a sheet surface direction of the base, and the light deflection element has a lower refractive index than the base. The upper surface of the light deflection element is formed in the shape of a polygonal line or a curve projecting downward in a longitudinal section along the thickness direction of the daylighting member, and the upper surface is formed of the base portion. The angle formed with respect to the normal line direction may be larger on the front side than on the back side.

  Here, when the upper side surface of the light deflection element is formed in a polygonal line in a longitudinal section along the thickness direction of the daylighting member, the predetermined angle is such that the upper and lower sides and the front and back of the daylighting member are in the specified direction. When the light is incident on the surface from a direction inclined upward, the angle formed by the traveling direction of the light with respect to the normal direction is the surface side of the upper side surface. It is preferable that the plane portion closest to is set to be larger than an angle formed with respect to the normal direction.

  Further, the predetermined angle is such that when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides and the front and back of the daylighting member are arranged in the prescribed direction, the light is incident on the upper side surface. It is preferable to set so that it may enter only into the plane part nearest to the said surface side.

  In the processing step, an indicator indicating a direction may be provided on the daylighting member based on the determination result of the direction determination step.

  Further, in the case where an index indicating the direction is provided in advance in the daylighting member, in the processing step, the correctness of the index is confirmed based on the determination result of the direction determination step, and the direction indicated by the index and the actual If the direction of the daylighting member is different, the index may be corrected.

  The present invention also includes a light deflection element that totally reflects light incident on the surface from a direction inclined upward at an angle within a design angle range in a state where the upper and lower sides and the front and back sides are arranged in a prescribed direction, A preparation step of preparing a daylighting member that emits light totally reflected by the element from the back surface, and a direction determination step of discriminating at least one of upper and lower and front and back of the daylighting member, and in the direction determination step, Test light is incident on the daylighting member from a direction inclined at a predetermined angle within the design angle range, and at least one of the upper and lower sides and the front and back sides of the daylighting member is based on the outgoing light emitted from the daylighting member. A method for discriminating the direction of a daylighting member is provided.

  The predetermined angle is such that when light is incident on the back surface from a direction inclined upward in a state where the front and back of the daylighting member are arranged opposite to the prescribed direction, the light is deflected by the light deflection element. It is preferable that the angle is set so as not to totally reflect.

  The predetermined angle is determined when the light is incident on the surface from a direction inclined upward in a state where the upper and lower sides of the daylighting member are installed opposite to the prescribed direction. It is preferable that the angle is set so as not to be totally reflected by the element.

  The daylighting member includes a base formed in a sheet shape and a plurality of the light deflection elements arranged in a sheet surface direction of the base, and the light deflection element has a lower refractive index than the base. The upper surface of the light deflection element is formed in the shape of a polygonal line or a curve projecting downward in a longitudinal section along the thickness direction of the daylighting member, and the upper surface is formed of the base portion. The angle formed with respect to the normal line direction may be larger on the front side than on the back side.

  Here, when the upper side surface of the light deflection element is formed in a polygonal line in a longitudinal section along the thickness direction of the daylighting member, the predetermined angle is such that the upper and lower sides and the front and back of the daylighting member are in the specified direction. When the light is incident on the surface from a direction inclined upward, the angle formed by the traveling direction of the light with respect to the normal direction is the surface side of the upper side surface. It is preferable that the plane portion closest to is set to be larger than an angle formed with respect to the normal direction.

  Further, the predetermined angle is such that when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides and the front and back of the daylighting member are arranged in the prescribed direction, the light is incident on the upper side surface. It is preferable to set so that it may enter only into the plane part nearest to the said surface side.

  According to the present invention, a desired lighting performance can be obtained by easily discriminating the direction of the daylighting member and installing or allowing the daylighting member to be installed in the correct direction.

It is the schematic of the opening structure with a lighting function manufactured by the manufacturing method by the 1st Embodiment of this invention. It is a front view of the laminated glass as a lighting member which comprises the said opening structure. It is a longitudinal cross-sectional view of the said opening structure. It is a principal part enlarged view of FIG. It is an enlarged view of the lighting sheet contained in the said laminated glass. It is a figure explaining the direction discrimination | determination process of the manufacturing method by 1st Embodiment. It is a figure explaining the detail of the said direction discrimination | determination process. It is a figure explaining the manufacturing method of the lighting member by the 2nd Embodiment of this invention. It is a figure explaining the example which performs a direction discrimination | determination process with respect to the lighting member of a structure different from the lighting member discriminated in the direction discrimination | determination process in 1st Embodiment and 2nd Embodiment. The example which performs a direction discrimination | determination process with respect to the lighting member by which the discrimination | determination was performed in the direction discrimination | determination process in 1st Embodiment and 2nd Embodiment, and the lighting member of a structure different from the daylighting member shown in FIG. It is a figure explaining. The direction discriminating step is performed on the daylighting member discriminated in the direction discriminating step in the first embodiment and the second embodiment and the daylighting member having a different configuration from the daylighting member shown in FIGS. It is a figure explaining an example. It is a figure explaining the intensity | strength of the light radiate | emitted from the lighting member in the direction discrimination | determination process concerning an Example.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  Further, in this specification, the terms “sheet”, “film”, and “plate” are not distinguished from each other only based on the difference in designation. For example, the “sheet” is a concept including a member that can be called a film or a plate.

  Further, as used in the present specification, the shape and geometric conditions and the degree thereof are specified, for example, terms such as “parallel”, “orthogonal”, “identical”, etc. are not bound to a strict meaning, Interpretation should include the extent to which similar functions can be expected.

  Furthermore, the “sheet surface (film surface, plate surface)” means the target sheet-like member (film-like member) when the target sheet-like (film-like, plate-like) member is viewed as a whole and globally. , A plate-like member) means a surface coinciding with the planar direction.

<First Embodiment>
In the first embodiment, a method for manufacturing an aperture structure with a daylighting function will be described. FIG. 1 is a schematic view of an aperture structure 1 with a daylighting function (hereinafter abbreviated as aperture structure 1) manufactured in the present embodiment. FIG. 2 is a front view of a laminated glass 10 as a daylighting member constituting the opening structure 1, and FIG. 3 is a longitudinal sectional view of the opening structure 1. Below, the schematic structure of the opening structure 1 and the laminated glass 10 is demonstrated first.

(Opening structure with daylighting function and laminated glass)
In FIG. 1, symbol W indicates a wall in a building as a structure, and an opening 2 is formed in the wall W. The opening structure 1 manufactured by this Embodiment is comprised by installing the laminated glass 10 as a lighting member in the opening part 2. As shown in FIG. In the opening structure 1, sunlight from the outdoor side, which is the side indicated by the arrow OUT in the figure, is incident on the laminated glass 10, and this incident light is incident on the indoor side, which is the side indicated by the arrow IN, with the desired lighting performance. Daylight.

  The laminated glass 10 includes a rectangular daylighting sheet 20, a rectangular outer panel 12 and an inner panel 13 sandwiching the daylighting sheet 20, and outer peripheral edges of the panels 12 and 13 in a state where the daylighting sheet 20 is sandwiched. And a surrounding frame member 14 having a rectangular frame shape.

  Among these, the daylighting sheet 20 is a member having daylighting performance. The panels 12 and 13 are translucent plate-like translucent panels that are used for ordinary buildings or vehicle windows, such as glass panels and resin panels. The frame member 14 is a member for holding the laminated glass 10 in the opening 2.

  1 and 3, the symbol V indicates the vertical direction. In this example, the laminated glass 10 is installed and used in the opening 2 so that the plate surfaces of the panels 12 and 13 are along the vertical direction. Specifically, the laminated glass 10 has an upper part 10U and a lower part 10D, the upper part 10U faces upward, the lower part 10D faces downward, the outer panel 12 faces the outdoor side, and the inner panel 13 faces the indoor side. And the board surface of the panels 12 and 13 is installed and used in the state which follows a perpendicular direction.

  In the use state as described above, the laminated glass 10 deflects the light incident on the outer panel 12 so that a desired lighting performance can be obtained by the daylighting sheet 20, as indicated by a plurality of arrows in FIG. The light is emitted from the inner panel 13. In the figure, reference numeral 10A indicates the surface of the outer panel 12 facing the outdoor side where light is incident, and reference numeral 10B indicates the rear surface of the inner panel 13 facing the indoor side where light is emitted. Yes. Moreover, the code | symbol H in a figure has shown the normal line direction of the laminated glass 10 thru | or the lighting sheet 20 orthogonal to the surface 10A and the back surface 10B. This normal H extends in parallel to the horizontal direction.

As shown in FIG. 4, the daylighting sheet 20 is bonded to the outer panel 12 via the first adhesive layer 31 and is bonded to the inner panel 13 via the second adhesive layer 32. The adhesive layers 31 and 32 are a thermoplastic resin or the like and have translucency. The daylighting sheet 20 includes a base portion 21 formed in a sheet shape and a plurality of light deflection elements 22 arranged in the sheet surface direction of the base portion 21. The base 21 is formed with a plurality of grooves 21 </ b> A that are spaced apart along the sheet surface direction. An optical deflection element 22 is disposed in each of the grooves 21A. Further, the light deflection elements 22 is made of a material of lower refractive index _{N B} than the refractive index _{N A} of the base portion 21. In FIG. 4, for convenience of explanation, the base 21 is not hatched.

  In FIG. 5, the light deflection element 22 is shown enlarged. As shown in FIG. 5, the upper side surface 22 </ b> U of the light deflection element 22 is formed in a convex broken line shape downward in a longitudinal section along the thickness direction of the daylighting sheet 20. Specifically, the upper side surface 22U has two planar portions, a first surface portion 23A located on the front surface 10A side and a second surface portion 23B located on the back surface 10B side. The angle formed by the first surface portion 23A with respect to the normal direction H is larger than the angle formed by the second surface portion 23B with respect to the normal direction H. On the other hand, the lower surface 22D of the light deflection element 22 is formed so as to extend linearly in a sectional view.

  In FIG. 5, the symbol α indicates an angle formed by the first surface portion 23A of the upper side surface 22U with the normal direction H, and the symbol β indicates that the second surface portion 23B of the upper side surface 22U is in the normal direction H. The angle between the two is shown. Here, the relationship of α> β holds. Symbol γ indicates an angle formed by the lower side surface 22D and the normal direction H. Furthermore, the symbol a indicates the length dimension in the normal direction H (thickness direction) of the first surface portion 23A, and the symbol b indicates the length dimension in the normal direction H (thickness direction) of the second surface portion 23B. Show. The symbol h indicates the distance in the sheet surface direction between the end portion on the surface 10A side of the first surface portion 23A and the end portion on the surface 10A side of the lower surface 22D of the other light deflection element 22 adjacent above. ing.

  In such a daylighting sheet 20, in the state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction” shown in the drawing, the above-described light deflection element 22 is located above the design angle range as shown in FIG. The angle α of the first surface portion 23A, the angle β of the second surface portion 23B, and the like are designed so that light incident on the surface 10A from a direction inclined at an angle within Ra is totally reflected. The light deflecting element 22 emits the totally reflected light so as to jump upward from the back surface 10B. Thereby, in the laminated glass 10, desired lighting performance is obtained. In addition, in this example, the state in which the upper and lower sides and the front and back of the laminated glass 10 are arranged in the “specified direction” means that the laminated glass 10 has an upper portion 10U facing upward, a lower portion 10D facing downward, and an outside where light enters. It means that the panel 12 faces the outdoor side, the inner panel 13 faces the indoor side, and the plate surfaces of the panels 12 and 13 are in a state along the vertical direction.

For example, θ1 and θ2 shown in FIG. 5 indicate a certain angle within the design angle range Ra. Of these, light incident from the direction of the angle θ1 is refracted in the interior of the base 21, at an angle inclined by theta _A with respect to the first surface portion 23A of the light deflection elements 22, incident on the first face 23A, It is totally reflected and emitted upward. The light incident from the direction of the angle θ2 is refracted in the interior of the base 21, at an angle inclined by theta _B with respect to the second face 23B of the light deflection elements 22, incident on the second face 23B, the total The light is reflected and emitted upward. As described above, the light deflection element 22 is designed to have an angle α, an angle β, or the like so that light incident at an angle within the design angle range Ra is totally reflected by the first surface portion 23A or the second surface portion 23B. .

In FIG. 5, the inner panel 12 and the first adhesive layer 31 are omitted. In this example, for convenience of explanation, it is assumed that the refractive indexes of the inner panel 12, the first adhesive layer 31, and the base 21 are the same. Accordingly, as shown in FIG. 5, when the refractive index of the outdoor and _{N 0,} the light incident on the surface 10A at an angle θ1 _is traveling within the base 21 while satisfying the relation of N 0 sinθ1 ₌ N A sinθx . Therefore, the angle θ _A at which the traveling direction of the light in the daylighting sheet 20 (in the base portion 21) is inclined with respect to the first surface portion 23A is calculated as θ _A = θx−α. On the other hand, the light incident on the surface 10A at an angle _θ2, the traveling within the base 21 while satisfying the relation of N 0 sinθ2 ₌ N A sinθy. Therefore, the angle θ _B at which the traveling direction of the light in the daylighting sheet 20 (in the base portion 21) is inclined with respect to the second surface portion 23B is calculated as θ _B = θy−β.

  On the other hand, in the daylighting sheet 20, when the top and bottom and the front and back of the laminated glass 10 are not arranged in the “specified direction”, for example, when the up and down direction is opposite to the “specified direction”, the design angle is upward. Even when light is incident from a direction inclined at an angle within the range Ra, a desired lighting performance cannot be obtained, in other words, a lighting performance different from the desired lighting performance is obtained. Therefore, even when light is incident under the same conditions between the state in which the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction” and the state in which they are not, the lighting performance is different. It has become.

  Specifically, in a state where the upper and lower sides and the front and back sides are arranged in the “specified direction”, when light is incident upward from a direction inclined at an angle within the design angle range Ra, the light is deflected by the light deflection element 22. As a result, there is obtained an emission mode in which the light is totally reflected and emitted so as to jump upward from the back surface 10B. On the other hand, in a state where the upper and lower sides and the front and back sides are not arranged in the “specified direction”, different emission modes can be obtained even when light is incident under the same conditions. Therefore, desired lighting performance cannot be obtained.

  As described above, when the laminated glass 10 described above is in a state where the top and bottom and the front and back are not arranged in the “specified direction”, desired lighting performance cannot be obtained. Therefore, if the direction of the laminated glass 10 is installed in the opening 2 in an inappropriate state, the opening structure 1 cannot exhibit the desired lighting performance. In order to prevent such a situation, the manufacturing method of the opening structure 1 of this embodiment described below includes a step of determining the direction of the laminated glass 10 before installing the laminated glass 10 in the opening 2 of the wall W. Prepare. Thereafter, the laminated glass 10 is appropriately installed in the opening 2.

(Manufacturing method of aperture structure with daylighting function)
Hereinafter, the manufacturing method according to the present embodiment will be described in detail. As an outline, the manufacturing method of the aperture structure with a lighting function 1 according to the present embodiment includes a preparation process for preparing the laminated glass 10 described above, a direction determination process for determining the top and bottom and the front and back of the laminated glass 10, and a direction determination process. And an installation step of configuring the opening structure 1 by installing the laminated glass 10 in the opening 2 of the wall W based on the determination result.

  Among these, in the direction determination step, the test light Lt is incident on the laminated glass 10 from a direction inclined at a predetermined angle θt within the design angle range Ra, and based on the emitted light emitted from the laminated glass 10, The top and bottom and the front and back of the laminated glass 10 are discriminated.

  FIG. 6 is a diagram for explaining the direction determining step according to the present embodiment. As shown in the figure, in the present embodiment, the laminated glass 10 is held in a state along the vertical direction, and the test light Lt is incident on the laminated glass 10 from a direction inclined upward at a predetermined angle θt. The outgoing light is irradiated onto the wall surface Ws. In addition, when holding the laminated glass 10 in a state along the vertical direction, ideally, the laminated glass 10 is held so as to be strictly parallel to the vertical direction, but may be slightly inclined with respect to the vertical direction. I do not care. In this example, the point light source device 100 is used as a device for emitting the test light Lt. The test light Lt is preferably light that has high straightness. The point light source device 100 is preferably a small light source that can be easily handled by an operator by hand. Therefore, as the point light source device 100, for example, a laser pointer or the like is suitable.

  As described above, in a state where the top and bottom and the front and back of the laminated glass 10 are arranged in the “specified direction”, when light is incident upward from a direction inclined at an angle within the design angle range Ra, An emission mode is obtained in which the light is totally reflected by the light deflection element 22 and is emitted so as to jump upward from the back surface 10B. On the other hand, in the state where the top and bottom and the front and back of the laminated glass 10 are not arranged in the “specified direction”, even when light is incident under the same conditions as described above, different emission modes are obtained.

  Therefore, when the laminated glass 10 is held in a state along the vertical direction as described above and the test light Lt is incident on the laminated glass 10 from a direction inclined upward by a predetermined angle θt, Depending on the direction, the emission pattern of the emitted light is different, resulting in a difference in the irradiation pattern on the wall surface Ws. In the direction discriminating step according to the present embodiment, the direction of the laminated glass 10 is discriminated based on such a difference in irradiation pattern.

  Specifically, when the laminated glass 10 is held in a state along the vertical direction, the surface 10A faces the incident side of the test light Lt, and the upper and lower sides and the front and back of the laminated glass 10 are arranged in the “specified direction”. Since the incident light is totally reflected, the emitted light is emitted so as to jump upward by the light deflecting element 22, and an irradiation pattern in which the emitted light is irradiated on the upper side of the wall surface Ws is confirmed. obtain. On the other hand, in a state where the surface 10A of the laminated glass 10 faces away from the side on which the test light Lt is incident, or in a state where the upper portion 10U faces downward, the irradiation that can be confirmed in the “specified direction” state. An irradiation pattern different from the pattern can be confirmed. Specifically, in the present embodiment, the direction of the laminated glass 10 can be determined from such a difference in irradiation pattern.

  That is, when the irradiation pattern in which the emitted light is irradiated on the upper side of the wall surface Ws is confirmed, the direction of the surface 10A and the upper part 10U of the laminated glass 10 can be specified, and when other irradiation patterns are confirmed. Since the directions of the surface 10A and the upper portion 10U cannot be clearly specified, the surface 10A of the laminated glass 10 can be obtained by repeating the operation of the direction determination step until the irradiation pattern irradiated with the emitted light is confirmed on the upper side of the wall surface Ws. And the direction of the upper portion 10U can be specified.

  As described above, according to the direction determining step according to the present embodiment, the test light Lt is incident on the laminated glass 10 from the direction inclined at the predetermined angle θt within the design angle range Ra, and is emitted from the laminated glass 10. By confirming the emitted light, the direction of the laminated glass 10 can be easily determined.

  Here, as the predetermined angle θt described above, an angle within the design angle range Ra can be selected, but depending on the selected angle, there is no clear difference in the irradiation pattern that differs depending on the direction of the laminated glass 10. There is a case. As a result, a situation may occur in which the direction of the laminated glass 10 cannot be easily and accurately determined. Therefore, in the present embodiment, in order to easily and accurately determine the direction of the laminated glass 10, the predetermined angle θt is set so as to satisfy the conditions 1 to 5 described below.

(Condition 1)
First, as condition 1, the predetermined angle θt is obtained when the test light Lt is incident on the surface 10A from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”. The angle at which this light is totally reflected by the first surface portion 23A of the light deflection element 22 is set.

  In the present embodiment, the incident test light Lt can be totally reflected by the first surface portion 23A or the second surface portion 23B as long as the angle is within the design angle range Ra. However, when the test light Lt is totally reflected by both the first surface portion 23A and the second surface portion 23B, the emitted light is radiated to the wall surface Ws over a wide range, and the irradiation pattern tends to become difficult to become a characteristic state. On the other hand, when the test light Lt is totally reflected mainly by the first surface portion 23, the emitted light can be spot-irradiated on the wall surface Ws, and the irradiation pattern can be characteristic. When the irradiation pattern is characteristic, the direction (surface 10A and upper part 10U) of the laminated glass 10 can be easily and accurately determined. Therefore, the condition 1 is set as a premise for the test light Lt to be totally reflected mainly by the first surface portion 23A and to make the emission light irradiation pattern characteristic.

  This condition 1 is that when the test light Lt is incident on the surface 10A from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”, the traveling direction of the light is legal. It is a condition that the predetermined angle θt is set so that the angle formed with respect to the line direction H is larger than the angle formed with respect to the normal direction H by the first surface portion 23A of the upper side surface 22U. . In addition, when the test light Lt is incident on the surface 10A, the angle formed by the light traveling direction with respect to the normal direction H is smaller than the critical angle of total reflection in the first surface portion 23A. And a predetermined angle θt is set.

  Strictly speaking, referring to the angle and refractive index shown in FIG. 5, the light incident at an angle inclined by an angle θx formed with respect to the normal direction H in the base 21 of the daylighting sheet 20 is expressed by the following equation ( Total reflection in the range of 1).

α <θx <α + 90 ° -arcsin (N _B / N _A ) (1)

  Based on the above formula (1), the predetermined angle θt that satisfies the condition 1 is expressed by the following formula (2).

arcsin ((N _B / N ₀ ) sin α) <θt <arcsin ((N _A / N ₀ ) sin (α + 90 ° -arcsin (N _B / N _A )) (2)

(Condition 2)
Next, as condition 2, the predetermined angle θt is determined when the test light Lt is incident on the surface 10A from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”. The angle at which this light is not totally reflected by the second surface portion 23B of the light deflection element 22 is set.

  As described above, when the test light Lt is totally reflected by both the first surface portion 23A and the second surface portion 23B, the emitted light is radiated to the wall surface Ws in a wide range, and the irradiation pattern tends not to be in a characteristic state. There is. On the other hand, when the test light Lt is totally reflected mainly by the first surface portion 23, the emitted light can be spot-irradiated on the wall surface Ws, and the irradiation pattern can be characteristic. Here, when the test light Lt is not totally reflected by the second surface portion 23B but is totally reflected only by the first surface portion 23, the emitted light can be clearly spot-irradiated on the wall surface Ws, and the irradiation pattern Can be clearly characteristic. Therefore, the condition 2 is set so that the test light Lt is totally reflected only by the first surface portion 23 and the emission light irradiation pattern is clearly characteristic. Thus, when the test light Lt is incident on the surface 10A from the direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”, the characteristic is irradiated in a spot manner. From the irradiation pattern, it can be easily determined that the state of the laminated glass 10 on which the test light Lt is incident is in the “specified direction”. From this, it becomes possible to easily determine the direction of the laminated glass 10.

  With reference to the angle and refractive index shown in FIG. 5, the light incident at an angle θy inclined with respect to the normal direction H in the base portion 21 of the daylighting sheet 20 is in the range of the following formula (3). , Not totally reflective.

θy−β> 90 ° −arcsin (N _B / N _A ) (3)

  Based on the above equation (3), the predetermined angle θt that satisfies the condition 2 is expressed by the following equation (4).

arcsin ((N _B / N ₀ ) sin (β + 90 ° −arcsin (N _B / N _A )) <θt (4)

(Condition 3)
Next, as the condition 3, the predetermined angle θt is set so that the front and back surfaces of the laminated glass 10 are arranged opposite to the “specified direction” and the upper and lower directions are correctly arranged, and the back surface from the direction inclined upward. When light is incident on 10B, the angle is set such that the light is not totally reflected by the second surface portion 23B of the light deflection element 22. That is, referring to FIG. 5, when light is incident from the direction of arrow X, a predetermined angle θt is set to an angle at which this light is not totally reflected by the second surface portion 23B of the light deflection element 22. .

  When the front and back surfaces of the laminated glass 10 are arranged opposite to the “prescribed direction” and the upper and lower directions are correctly arranged, when the light is incident on the back surface 10B from the direction inclined upward, the light is When the light beam is totally reflected by the second surface portion 23B of the light deflection element 22, the irradiation pattern is emitted light when the test light Lt is incident in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”. It is difficult to make a clear difference with respect to the irradiation pattern. Therefore, the condition 3 clarifies the difference between the irradiation pattern of the emitted light in the state where the upper and lower sides and the front and back of the laminated glass 10 are arranged in the “prescribed direction” and the irradiation pattern in the state where the laminated glass 10 is not, It is set so that the direction can be easily discriminated.

  The predetermined angle θt that satisfies the condition 3 is expressed by the following equation (5).

arcsin ((N _B / N ₀ ) sin (−β + 90 ° −arcsin (N _B / N _A )) <θt (5)

(Condition 4)
Next, as the condition 4, the predetermined angle θt is obtained when light is incident on the back surface 10B from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged opposite to the “specified direction”. In addition, the light is set at an angle at which the light is not totally reflected by the lower surface 22D of the light deflection element 22. That is, referring to FIG. 5, when light is incident from the direction of arrow Y, a predetermined angle θt is set to an angle at which this light is not totally reflected by the lower side surface 22D of the light deflection element 22.

  When the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged opposite to the “prescribed direction”, when light is incident on the back surface 10B from the upwardly inclined direction, the light is below the light deflection element 22. When totally reflected by the side surface 22D, the irradiation pattern is clear with respect to the irradiation pattern of the emitted light when the test light Lt is incident in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”. Differences can be less likely to occur. Therefore, the condition 4 clarifies the difference between the irradiation pattern of the emitted light in a state where the upper and lower sides and the front and back of the laminated glass 10 are arranged in the “prescribed direction” and the irradiation pattern in a state other than that, It is set so that the direction can be easily discriminated.

  The predetermined angle θt that satisfies the condition 4 is expressed by the following equation (6).

arcsin ((N _B / N ₀ ) sin (γ + 90 ° −arcsin (N _B / N _A )) <θt (6)

(Condition 5)
Next, as a condition 5, the predetermined angle θt is determined when light is incident on the surface 10A from a direction inclined upward in a state where the upper and lower sides of the laminated glass 10 are arranged opposite to the “specified direction”. The light is set at an angle at which the light is not totally reflected by the lower surface 22D of the light deflection element 22. That is, referring to FIG. 5, when light is incident from the direction of arrow Z, a predetermined angle θt is set to an angle at which this light is not totally reflected by lower surface 22D of deflection element 22.

  In a state where the upper and lower sides of the laminated glass 10 are arranged opposite to the “prescribed direction”, when light is incident on the surface 10B from a direction inclined upward, the light is incident on the lower side surface 22D of the light deflection element 22. When the test light Lt is incident when the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”, the irradiation pattern is clearly different from the irradiation pattern of the emitted light. It can be difficult to occur. Therefore, the condition 5 clarifies the difference between the irradiation pattern of the emitted light in a state where the upper and lower sides and the front and back of the laminated glass 10 are arranged in the “specified direction” and the irradiation pattern in a state other than that, It is set so that the direction can be easily discriminated.

  The predetermined angle θt that satisfies the condition 5 is expressed by the following equation (7).

arcsin ((N _B / N ₀ ) sin (−γ + 90 ° −arcsin (N _B / N _A )) <θt (7)

  When the predetermined angle θt is set so as to satisfy the above conditions 1 to 5, the irradiation pattern of the emitted light with the top and bottom and the front and back of the laminated glass 10 arranged in the “specified direction”, and so on It becomes possible to determine the direction of the laminated glass 10 easily and accurately by clarifying the difference from the irradiation pattern in a state that is not.

  Specifically, as shown in FIG. 7A, in a state where the top and bottom and the front and back of the laminated glass 10 are arranged in the “specified direction”, the test light Lt is applied from the direction inclined at a predetermined angle θt. In this case, an irradiation pattern in which the emitted light is irradiated on the upper side of the wall surface Ws (see FIG. 6) is confirmed.

  On the other hand, as shown in FIG. 7 (B), the front and back of the laminated glass 10 are arranged opposite to the “specified direction”, and the direction in which the upper and lower directions are correctly arranged is inclined at a predetermined angle θt. When the test light Lt is incident on the laminated glass 10 from above, an irradiation pattern in which the emitted light is irradiated on the lower side of the wall surface Ws is confirmed.

  Further, as shown in FIG. 7C, the test light Lt is applied to the laminated glass 10 from a direction inclined at a predetermined angle θt in a state where the top and bottom and the front and back of the laminated glass 10 are arranged opposite to the “specified direction”. When the light enters the irradiation pattern, the irradiation pattern irradiated with the emitted light on the lower side of the wall surface Ws is confirmed.

  7D, the test light Lt is incident on the laminated glass 10 from a direction inclined at a predetermined angle θt in a state where the upper and lower sides of the laminated glass 10 are arranged opposite to the “specified direction”. In such a case, an irradiation pattern in which the emitted light is irradiated on the lower side of the wall surface Ws is confirmed.

  When the predetermined angle θt is set so as to satisfy the conditions 1 to 5 in this way, the top and bottom and the front and back of the laminated glass 10 are “when the irradiation pattern is irradiated with light on the upper side of the wall surface Ws. If it is arranged in the “specified direction” and other irradiation patterns, it can be easily and accurately determined that the top and bottom and the front and back of the laminated glass 10 are not arranged in the “specified direction” based on the irradiation pattern. Therefore, it is possible to easily and accurately determine the direction of the laminated glass 10.

  Here, in addition to the above conditions 1 to 5, it is more preferable that the predetermined angle θt satisfies the following condition 6.

(Condition 6)
In Condition 6, when the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”, when light is incident on the surface 10A from the direction inclined upward, the light is incident on the first of the upper side surfaces 22U. The condition that it is set so as to be incident only on the first surface portion 23A is satisfied to a predetermined angle θt.

  In this case, the test light Lt is totally reflected only by the first surface portion 23, and the emitted light is spot-irradiated on the wall surface Ws, so that the irradiation pattern becomes remarkably characteristic. Therefore, it becomes easier to determine the direction of the laminated glass 10 based on this irradiation pattern.

  The predetermined angle θt that satisfies the condition 6 is expressed by the following equation (8).

arcsin ((N _A / N ₀ ) sin (arctan (tan α + (h / A)))) <θt <arcsin ((N _A / N ₀ ) sin (α + 90 ° −arcsin (N _B / N _A ))・ (8)

The above formula (8) is applicable only when arctan (tan α + (h / A)) <α + 90 ° -arcsin (N _B / N _A ) holds.

  And after the above-mentioned direction discrimination | determination process, the laminated glass 10 by which the direction was discriminate | determined is installed in the opening part 2, and the opening structure 1 is comprised.

  In the present embodiment described above, in the direction determination step, the test light Lt is incident on the laminated glass 10 from the direction inclined at the predetermined angle θt within the design angle range Ra, and the emitted light emitted from the laminated glass 10 is emitted. Based on the above, the top and bottom and front and back of the laminated glass 10 are determined.

  The predetermined angle θt in this direction determining step is that the light is deflected when light is incident from a direction inclined at the angle when the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”. This is the angle at which element 22 totally reflects. Therefore, the emitted light is emitted in the form of being totally reflected by the light deflection element 22 and emitted. On the other hand, in the state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are not arranged in the “specified direction”, the light deflection element 22 is intentionally all even if light is incident from a direction inclined by a predetermined angle θt. Not designed to reflect. Therefore, the emitted light is emitted in an emission mode different from the “prescribed direction” state.

  Thereby, in this direction discrimination | determination process, the upper and lower sides and front and back of the laminated glass 10 can be confirmed in the state of a "prescribed direction" only by making the test light Lt inject into the laminated glass 10 from the direction inclined by predetermined angle (theta) t. It is possible to make a difference between the emission mode and the output mode that can be confirmed in a state other than that. The direction of the laminated glass 10 can be determined from the difference in the emission mode.

  Thereby, according to this Embodiment, the direction of the laminated glass 10 is easily discriminate | determined, and when the laminated glass 10 is installed or can be installed in the correct direction in the opening part 2, in the opening structure 1, desired The lighting performance can be obtained.

  In particular, according to the present embodiment, the test light Lt is incident on the laminated glass 10 and the emitted light is irradiated onto the wall surface Ws, and the direction of the laminated glass 10 is visually determined from the difference in the irradiation pattern. . In this case, since the direction of the laminated glass 10 can be determined by visually confirming the irradiation pattern, the direction determining step can be performed easily and efficiently.

  Further, according to the present embodiment, the light is incident on the back surface 10A from the direction inclined upward in the state where the predetermined angle θt is arranged so that the front and back surfaces of the laminated glass 10 are opposite to the “specified direction”. In this case, the light is set to an angle at which the light is not totally reflected by the light deflection element 22 (condition 3 and condition 4). Further, when light is incident on the surface 10A from a direction inclined upward in a state where the upper and lower surfaces of the laminated glass 10 are arranged opposite to the specified direction, the light is deflected by the light deflection element 22. The angle is set so as not to totally reflect (Condition 5). Thereby, the difference between the emission mode (irradiation pattern) of the emitted light in a state where the upper and lower sides and the front and back of the laminated glass 10 are arranged in the “specified direction” and the emission mode (irradiation pattern) in a state other than that are clarified. be able to. Therefore, according to this Embodiment, the direction of the laminated glass 10 can be discriminate | determined easily and correctly based on the clear difference of an emission aspect (irradiation pattern).

  In the present embodiment, the light deflection element 22 is asymmetric with respect to the normal direction H. However, when the daylighting sheet 20 is used in which the light deflection element 22 is symmetric with respect to the normal direction H, the vertical direction is discriminated. Is not necessarily performed. In this case, the condition 5 may not be satisfied. In this case, in the direction determination step, only front / back determination may be performed.

  Moreover, in this Embodiment, the laminated glass 10 which is the object of a direction discrimination | determination process WHEREIN: The base part 21 formed in the sheet shape in the daylighting sheet 20, and several light deflection | deviation element arranged in the sheet surface direction of the base part 21 22. The light deflection element 22 is made of a material having a refractive index lower than that of the base portion 21, and the upper side surface 22U of the light deflection element 22 is formed in a convex broken line shape downward in a longitudinal section along the thickness direction. The upper surface 22U has a larger angle on the front surface 10A side than the back surface 10B side with respect to the normal direction H. That is, the angle formed by the first surface portion 23A with respect to the normal direction H is larger than the angle formed by the second surface portion 23B with respect to the normal direction H.

  Here, in correspondence with the use of the daylighting sheet 20 as described above, according to the present embodiment, the predetermined angle θt is a state in which the upper and lower sides and the front and back sides of the laminated glass 10 are arranged in the “specified direction”. , The plane portion closest to the surface 10A side of the upper side surface 22U is the angle formed by the traveling direction of the light with respect to the normal direction H when light is incident on the surface 10A from the upwardly inclined direction. It is set so that (the first surface portion 23A) is larger than an angle formed with respect to the normal direction H. This is because when the test light Lt is incident on the surface 10A from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “prescribed direction”, the predetermined angle θt This means that the angle is such that the first surface portion 23A of the light deflection element 22 is easily totally reflected.

  As described above, when the test light Lt is totally reflected mainly by the first surface portion 23, the emitted light can be spot-irradiated on the wall surface Ws, and the irradiation pattern can be characteristic. When the irradiation pattern is characteristic, the direction of the laminated glass 10 can be easily determined based on the irradiation pattern. Therefore, in this embodiment, when light is incident on the surface 10A from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”, the traveling direction of the light is changed. A predetermined angle is set so that an angle formed with respect to the normal direction H is larger than an angle formed with respect to the normal direction H by a plane portion (first surface portion 23A) closest to the surface 10A side of the upper side surface 22U. An angle θt is set. Thereby, according to this Embodiment, it is possible to distinguish the direction of the laminated glass 10 easily and correctly based on the characteristic irradiation pattern.

  Further, in this case, as described in the condition 6, when the upper and lower surfaces and the front and back surfaces of the laminated glass 10 are arranged in the “specified direction”, light is incident on the surface 10A from the direction inclined upward. In this case, it is preferable that the light is set so as to be incident only on the flat surface portion (first surface portion 23A) closest to the surface 10A side of the upper side surface 22U. In this case, since the irradiation pattern becomes remarkably characteristic, the direction of the laminated glass 10 can be more easily and accurately determined based on the irradiation pattern.

In addition, in 1st Embodiment demonstrated above, although the example which manufactures the opening structure 1 was demonstrated by installing the laminated glass 10 as a lighting member in the opening part 2, the lighting sheet 20 as a lighting member was demonstrated. After the direction is determined, the opening structure may be manufactured by being attached to a window glass or the like. Further, the daylighting member installed in the opening 2 may be multi-layer glass (pair glass) or the like. The multilayer glass includes, for example, a sheet laminated panel in which the daylighting sheets 20 are laminated, and an outer panel and an inner panel arranged on both outer sides of the panel. The sheet laminated panel, the outer panel, and the inner panel It is a member in which a space (air layer) is provided between at least one of them. In this case, the opening structure is manufactured by determining the direction of the multilayer glass and then installing the opening structure in the opening.
The daylighting member may be a daylighting blind whose slat portion has a daylighting function, a daylighting roll screen formed in a roll screen shape, or the like. In this case, an opening structure is manufactured by installing a daylighting blind or a daylighting roll screen on the exit surface side of a window glass or the like. In the daylighting blind, for example, each slat part has the same structure as the daylighting sheet 20 described above. In this case, after determining the direction of such a lighting blind, an opening structure is manufactured by installing the lighting blind on the exit surface side of a window glass or the like. The daylighting roll screen includes, for example, a shaft member and a daylighting sheet 20 similar to that described above with one end attached to the shaft member. In this case, after determining the direction of the daylighting roll screen in this way, an opening structure is manufactured by installing the daylighting roll screen on the exit surface side of the window glass or the like.

  Moreover, the lighting member used as the object of a direction discrimination | determination process may have a light-diffusion function. For example, in the laminated glass 10 described above, the first adhesive layer 31 and the second adhesive layer 32 may have a light diffusing function, and the panel has a light diffusing function as typified by template glass or rubbed glass. You may have. Moreover, the daylighting sheet 20 may have a light diffusion layer. In this case, the light emitted from the emission surface of the daylighting member is diffused, but if the distance between the emission surface and the light receiving surface (wall surface Ws) that irradiates the emitted light is adjusted in the direction determination step, irradiation is performed. The direction of the daylighting member can be easily determined from the pattern. It can also be easily determined by darkening the surrounding illumination when determining the direction.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. In the present embodiment, a method for manufacturing a daylighting sheet as a daylighting member will be described. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and a part of the description is omitted.

  FIG. 8 is a diagram illustrating a method for manufacturing the daylighting sheet 20 according to the present embodiment. As a summary, the manufacturing method of the daylighting sheet 20 according to the present embodiment includes a preparation step of preparing the daylighting sheet 20 described in the first embodiment, a direction determination step of discriminating the upper and lower sides and the front and back of the daylighting sheet 20, And a processing step of processing the daylighting sheet 20 based on the determination result of the direction determination step.

  FIG. 8A is a diagram for explaining a direction determining step in the present embodiment. As shown in the figure, in this embodiment, the daylighting sheet 20 is held in a state along the vertical direction, and the test light is viewed from a direction inclined upward at a predetermined angle θt, as in the first embodiment. Lt is incident on the laminated glass 10 and the emitted light is irradiated onto the wall surface Ws. Also in this example, the point light source device 100 is used as a device that emits the test light Lt.

  Since the contents of the direction determination step are the same except that the laminated glass 10 is replaced with the daylighting sheet 20, detailed description thereof is omitted.

  On the other hand, FIG. 8B is a diagram illustrating a processing step in the present embodiment. In the processing step according to the present embodiment, an index indicating the direction is provided on the daylighting sheet 20 based on the determination result of the direction determination step. Reference numeral 41 in the figure indicates an index indicating the top side (upper side), and reference numeral 42 indicates an index indicating the surface side. By discriminating the direction of the daylighting sheet 20 in the direction discriminating step and providing such indexes 41 and 42, the daylighting sheet 20 can be placed in the correct direction thereafter.

As a modification of the second embodiment, when an index indicating the direction is provided in advance on the daylighting sheet 20, the processing step corrects the index based on the determination result of the direction determination step. If the direction indicated by the index is different from the actual direction of the daylighting sheet 20 (the determined direction), the index may be corrected.
Further, here, the method for manufacturing a daylighting sheet as a daylighting member has been described, but the daylighting member may be a laminated glass, a multi-layer glass, a daylighting blind, a daylighting roll screen, or the like as described in the first embodiment. . In the case of manufacturing laminated glass, after determining the direction of the daylighting sheet, for example, in the processing step, the daylighting sheet is arranged between the glasses in a desired direction to produce laminated glass (multi-layer glass). Is the same). In the case of manufacturing the daylighting blind, the daylighting blind is manufactured by determining the direction of the slat part and then aligning and connecting the plurality of slat parts in a desired direction in, for example, a processing step. In the case of manufacturing the daylighting roll screen, after determining the direction of the daylighting sheet, for example, in the processing step, the daylighting roll screen is manufactured by connecting the daylighting sheet to the shaft member in a desired direction. In the case of manufacturing a daylighting sheet, after determining the direction of the daylighting sheet, for example, in the processing step, the daylighting sheet is used as a desired direction, and a functional layer such as an adhesive layer, a light diffusion layer, or a hard coat layer is coated You may laminate | stack on a daylighting sheet | seat using methods, such as a lamination.

(Modification of the daylighting member subject to the direction discrimination process)
Refer to FIGS. 9 to 11 for an example in which the direction determining step is performed on the daylighting member having a configuration different from the daylighting member determined in the direction determining step in the first embodiment and the second embodiment. However, it will be explained. In the description of this modification, the same components as those described in the first embodiment and the second embodiment will be described with the same reference numerals.

  In the daylighting sheet 20 ′ shown in FIG. 9, three planes of a first surface portion 23A, a second surface portion 23B, and a third surface portion 23C are arranged such that the upper side surface 22U of the light deflection element 22 is aligned from the incident side to the emission side. Has a part. The angle formed by the first surface portion 23A with respect to the normal direction H is larger than the angle formed by the second surface portion 23B with respect to the normal direction H, and the angle formed by the second surface portion 23B with respect to the normal direction H is The third surface portion 23C is larger than the angle formed with respect to the normal direction H. On the other hand, the lower surface 22D of the light deflection element 22 is formed so as to extend linearly in a sectional view.

  Also in such a daylighting sheet 20 ′, in a state where the upper and lower sides and the front and back sides are arranged in the “specified direction”, the direction in which the light deflection element 22 is inclined upward at an angle within the design angle range (for example, the angle in the drawing) The angle of the first surface portion 23A, the angle of the second surface portion 23B and the third surface portion 23C, etc. are designed so that light incident on the surface from the direction inclined by θ9) is totally reflected.

  On the other hand, also in this daylighting sheet 20 ′, when the upper and lower sides and the front and back sides are not arranged in the “prescribed direction”, for example, when the up and down direction is opposite to the “prescribed direction”, Even when light is incident from a direction inclined at an angle of, a desired lighting performance cannot be obtained. In other words, a lighting performance different from the desired lighting performance is obtained. That is, in a state where the top and bottom and the front and back are arranged in the “specified direction”, when light is incident upward from an angle inclined within the design angle range, the light is totally reflected by the light deflection element 22. Thus, an emission mode in which the light is emitted upward from the back surface is obtained. On the other hand, in a state where the upper and lower sides and the front and back sides are not arranged in the “specified direction”, different emission modes can be obtained even when light is incident under the same conditions.

  Therefore, also in such a daylighting sheet 20 ′, the same direction discrimination process as that in the first embodiment and the second embodiment can be performed. That is, as shown in FIG. 9, the test light Lt is incident from a direction inclined at a predetermined angle within the design angle range (for example, the direction inclined at an angle θ9 in the figure) and emitted from the daylighting sheet 20 ′. Based on the emitted light, at least one of the top and bottom and the front and back of the daylighting sheet 20 ′ can be determined.

  In the above-described predetermined angle according to this example, when the front and back of the daylighting sheet 20 are arranged opposite to the “prescribed direction”, when the light is incident on the back surface from the direction inclined upward, the light is It is preferable that the angle is set so as not to be totally reflected by the light deflection element 22 (conditions similar to the conditions 3 and 4 described in the first embodiment). That is, it is preferable that the angle is set so that the light is not totally reflected by the light deflection element 22 when light is incident from the direction of the arrow X or the arrow Y in FIG.

  In addition, the above-mentioned predetermined angle according to this example is also when the light is incident on the surface from the direction inclined upward in the state where the upper and lower sides of the daylighting sheet 20 ′ are arranged opposite to the “specified direction” It is preferable that the angle is set so that the light is not totally reflected by the light deflecting element 22 (the same condition as the condition 5 described in the first embodiment). That is, it is preferable that the angle is set so that the light is not totally reflected by the light deflection element 22 when light is incident from the direction of arrow Z in FIG.

  Next, in the daylighting sheet 20 ″ shown in FIG. 10, the upper side surface 22 </ b> U of the light deflection element 22 is formed so as to extend linearly in a sectional view. The upper side surface 22U is formed so as to be inclined downward toward the back surface side. On the other hand, the lower surface 22D of the light deflection element 22 is formed so as to extend linearly in a sectional view.

  Even in such a daylighting sheet 20 '', in a state where the upper and lower sides and the front and back sides are arranged in the "specified direction", the direction in which the light deflection element 22 is tilted upward at an angle within the design angle range (for example, The angle or the like of the upper side surface 22U is designed so that light incident on the surface from a direction inclined at an angle θ10) is totally reflected.

  On the other hand, also in the daylighting sheet 20 ″, when the top and bottom and the front and back are not arranged in the “specified direction”, for example, when the up and down direction is opposite to the “specified direction”, the design angle range is upward. Even when light is incident from a direction inclined at an inner angle, a desired lighting performance cannot be obtained. In other words, a lighting performance different from the desired lighting performance is obtained. That is, in a state where the top and bottom and the front and back are arranged in the “specified direction”, when light is incident upward from an angle inclined within the design angle range, the light is totally reflected by the light deflection element 22. Thus, an emission mode in which the light is emitted upward from the back surface is obtained. On the other hand, in a state where the upper and lower sides and the front and back sides are not arranged in the “specified direction”, different emission modes can be obtained even when light is incident under the same conditions.

  Therefore, also in such a daylighting sheet 20 ″, the same direction discriminating step as that in the first embodiment and the second embodiment can be performed. That is, as shown in FIG. 10, the test light Lt is incident from a direction inclined at a predetermined angle within the design angle range (for example, the direction inclined at an angle θ10 in the figure) and emitted from the daylighting sheet 20 ″. Based on the emitted light, at least one of the top and bottom and the front and back of the daylighting sheet 20 ″ can be determined.

  In the above-described predetermined angle according to this example, when the front and back of the daylighting sheet 20 are arranged opposite to the “prescribed direction”, when the light is incident on the back surface from the direction inclined upward, the light is It is preferable that the angle is set so as not to be totally reflected by the light deflection element 22 (conditions similar to the conditions 3 and 4 described in the first embodiment). That is, it is preferable that the angle is set so that the light is not totally reflected by the light deflection element 22 when light is incident from the direction of the arrow X or the arrow Y in FIG.

  Further, the above-mentioned predetermined angle according to this example is also obtained when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides of the daylighting sheet 20 '' are arranged opposite to the “prescribed direction”. It is preferable that the angle is set so that the light is not totally reflected by the light deflecting element 22 (the same condition as the condition 5 described in the first embodiment). That is, it is preferable that the angle is set so that the light is not totally reflected by the light deflection element 22 when light is incident from the direction of the arrow Z in FIG.

  Next, in the daylighting sheet 20 ″ ″ shown in FIG. 11, the upper side surface 22 </ b> U of the light deflection element 22 is formed in a curved shape that protrudes downward in a sectional view. On the other hand, the lower surface 22D of the light deflection element 22 is formed so as to extend linearly in a sectional view.

  Also in such a daylighting sheet 20 ′ ″, the direction in which the light deflection element 22 is inclined upward at an angle within the design angle range (for example, in the drawing) in a state where the upper and lower sides and the front and back sides are arranged in the “specified direction”. The shape of the upper side surface 22U and the like are designed so as to totally reflect light incident on the surface from a direction inclined at an angle θ11.

  On the other hand, also in the daylighting sheet 20 ′ ″, when the top and bottom and the front and back are not arranged in the “prescribed direction”, for example, when the up and down direction is opposite to the “prescribed direction”, the design angle is raised upward. Even when light is incident from a direction inclined at an angle within the range, a desired lighting performance cannot be obtained. In other words, a lighting performance different from the desired lighting performance is obtained. That is, in a state where the top and bottom and the front and back are arranged in the “specified direction”, when light is incident upward from an angle inclined within the design angle range, the light is totally reflected by the light deflection element 22. Thus, an emission mode in which the light is emitted upward from the back surface is obtained. On the other hand, in a state where the upper and lower sides and the front and back sides are not arranged in the “specified direction”, different emission modes can be obtained even when light is incident under the same conditions.

  Therefore, also in such a daylighting sheet 20 ″ ″, the same direction determination process as in the first and second embodiments can be performed. That is, as shown in FIG. 11, the test light Lt is incident from a direction inclined at a predetermined angle within the design angle range (for example, the direction inclined at an angle θ11 in the figure), and is emitted from the daylighting sheet 20 ′ ″. Based on the emitted light, at least one of the top and bottom and the front and back of the daylighting sheet 20 ′ ″ can be determined.

  In the state where the front and back of the daylighting sheet 20 ′ ″ are arranged opposite to the “specified direction”, the above-mentioned predetermined angle according to this example is also obtained when light is incident on the back surface from the direction inclined upward. It is preferable that the angle is set so that the light is not totally reflected by the light deflection element 22 (conditions similar to the conditions 3 and 4 described in the first embodiment). That is, it is preferable that the angle is set so that the light is not totally reflected by the light deflection element 22 when light is incident from the direction of the arrow X or the arrow Y in FIG.

  Further, the above-mentioned predetermined angle according to this example is also obtained when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides of the daylighting sheet 20 ′ ″ are arranged opposite to the “specified direction”. In addition, it is preferable that the angle is set so that the light is not totally reflected by the light deflecting element 22 (the same condition as the condition 5 described in the first embodiment). That is, it is preferable that the angle is set so that the light is not totally reflected by the light deflection element 22 when light is incident from the direction of the arrow Z in FIG.

<Example>
Next, a description will be given of an example in which the daylighting sheet 20 described in the first embodiment in which specific angles and dimensions are set is prepared, and a direction determination process is performed on the daylighting sheet 20. Referring to FIG. 5, the daylighting sheet 20 that is a target of the direction determination step used in this embodiment has the dimensions, angles, and refractive indexes shown in Table 1 below.

  The predetermined angle θt in this embodiment can be set to an angle within the design angle range Ra determined from the angle α and the angle β. However, in this example, the predetermined angle θt that satisfies the conditions 1 to 6 described in the first embodiment was calculated as follows.

Expression (2) that satisfies condition 1 is as follows.
arcsin ((N _B / N ₀ ) sin α) <θt <arcsin ((N _A / N ₀ ) sin (α + 90 ° -arcsin (N _B / N _A )) (2)

  Based on this equation, the predetermined angle θt satisfies the condition 1 as 22.5 ° <θt <70.8 °.

Expression (4) that satisfies condition 2 is as follows.
arcsin ((N _B / N ₀ ) sin (β + 90 ° −arcsin (N _B / N _A )) <θt (4)

  Based on this equation, the predetermined angle θt satisfies the condition 2 as 32.8 ° <θt.

Expression (5) that satisfies condition 3 is as follows.
arcsin ((N _B / N ₀ ) sin (−β + 90 ° −arcsin (N _B / N _A )) <θt (5)

  Based on this equation, the predetermined angle θt satisfies the condition 3 as 32.8 ° <θt.

Expression (6) that satisfies condition 4 is as follows.
arcsin ((N _B / N ₀ ) sin (γ + 90 ° −arcsin (N _B / N _A )) <θt (6)

  Based on this equation, the predetermined angle θt satisfies the condition 4 as 46.7 ° <θt.

Expression (7) that satisfies the condition 5 is as follows.
arcsin ((N _B / N ₀ ) sin (−γ + 90 ° −arcsin (N _B / N _A )) <θt (7)

  Based on this equation, the predetermined angle θt satisfies the condition 5 as 20.1 ° <θt.

  From the above, the predetermined angle θt that satisfies the conditions 1 to 5 is in the range of 46.7 ° <θt <70.8 °.

  In addition to the conditions 1 to 5, the predetermined angle θt that satisfies the condition 6 described in the first embodiment is calculated as follows.

That is, the equation (8) that satisfies the condition 6 is as follows.
arcsin ((N _A / N ₀ ) sin (arctan (tan α + (h / A)))) <θt <arcsin ((N _A / N ₀ ) sin (α + 90 ° −arcsin (N _B / N _A ))・ (8)

  Based on this expression, the predetermined angle θt that satisfies the condition 6 is 51.7 ° <θt <70.8 °.

  FIG. 12 shows that in this embodiment, the predetermined angle θt is set to 40 °, 50 °, 60 °, and 70 °, and emitted from the daylighting sheet 20 when the test light Lt is incident on the daylighting sheet 20. The outgoing intensity distribution of the emitted light is shown.

  12A shows a case where the predetermined angle θt is 40 °, FIG. 12B shows a case where the predetermined angle θt is 50 °, and FIG. 12C shows a case where the predetermined angle θt is 60 °. Indicates a case where the predetermined angle θt is 70 °.

  12A to 12D, the solid line indicates the emission intensity distribution when the surface faces the test light incident side and the lighting sheet 20 has upper and lower surfaces and the front and back surfaces are in the “specified direction”. The alternate long and short dash line indicates the emission intensity distribution in the case where the front and back of the daylighting sheet 20 are arranged opposite to the “specified direction” and the vertical direction is correctly arranged (front and back inversion). The alternate long and two short dashes line indicates the emission intensity distribution when the top and bottom and the front and back of the daylighting sheet 20 are arranged opposite to the “specified direction” (top and bottom reversed). The broken line shows the emission intensity distribution when the upper and lower sides of the laminated glass 10 are arranged opposite to the “specified direction” and the front and back directions are correctly arranged (upside down).

  Furthermore, in these emission intensity distributions, it means that the intensity of light is so large that the drawn curve extends to the outer peripheral side. In addition, the drawn curve extends upward with respect to the normal direction H, indicating that the light is bounced upward. The drawn curve extends downward with respect to the normal direction H. It shows that the light is emitted downward.

  As shown in FIG. 12A, when the predetermined angle θt is 40 °, there is no clear difference in emission intensity between the “specified direction” and the other cases, and thus the “specified direction”. It is difficult to visually discriminate that the daylighting sheet 20 to be discriminated is in the “specified direction” from the emission mode (irradiation pattern) of the emitted light. However, even in such a case, in the emission mode of the emitted light in the “specified direction”, a lot of light jumping upward is observed, and therefore, the direction of the daylighting sheet 20 is based on such characteristics. Can be determined.

  On the other hand, when the predetermined angle θt is 50 °, 60 °, and 70 ° satisfying the conditions 1 to 5, as shown in FIGS. 12B to 12D, the “specified direction” and other cases Therefore, the daylighting sheet 20 to be discriminated is visually determined in the “specified direction” from the emission mode (irradiation pattern) of the emitted light in the “specified direction”. It can be easily determined that there is. Therefore, from this result, if the predetermined angle θt is set so as to satisfy the conditions 1 to 5, it is possible to easily determine that the daylighting sheet 20 is in the “specified direction”. It was confirmed that the direction could be easily distinguished.

  Further, in FIGS. 12C and 12D that satisfy the condition 6, the intensity of the emitted light in the “specified direction” is larger than the other angle (50 °). In this case, the light jumping upward is clearly irradiated. Based on such characteristics, the direction of the daylighting sheet 20 can be easily determined. Therefore, from this result, if the predetermined angle θt is set so as to satisfy the condition 6, it is possible to easily and accurately determine that the daylighting sheet 20 is in the “specified direction”. It was confirmed that can be easily discriminated.

DESCRIPTION OF SYMBOLS 1 Opening structure with a lighting function 2 Opening part 10 Laminated glass 10A Surface 10B Back surface 10U Upper part 10D Lower part 12 Outer panel 13 Inner panel 14 Frame member 20,20 ', 20'',20''' Daylighting sheet 21 Base 21A Groove 22 Light Deflection element 22U Upper side surface 22D Lower side surface 23A First surface portion 23B Second surface portion 23C Third surface portion 31 First adhesive layer 32 Second adhesive layer θt Predetermined angle W Wall Lt Test light Ra Design angle range Ws Wall surface

Claims (20)

In a state where the upper and lower sides and the front and back sides are arranged in a prescribed direction, the optical deflection element includes a light deflection element that totally reflects light incident on the surface from a direction inclined at an angle within a design angle range, and is totally reflected by the light deflection element Preparing a daylighting member for emitting light from the back surface;
A direction discriminating step for discriminating at least one of upper and lower and front and back of the daylighting member;
Based on the discrimination result of the direction discrimination step, an installation step of installing the daylighting member in an opening formed in the structure to configure an aperture structure with a daylighting function;
With
In the direction discriminating step, test light is incident on the daylighting member from a direction inclined at a predetermined angle within the design angle range, and the upper and lower sides and the front and back sides of the daylighting member are based on the outgoing light emitted from the daylighting member. Determining at least one of the
Manufacturing method of aperture structure with daylighting function. The predetermined angle is such that when light is incident on the back surface from a direction inclined upward in a state where the front and back of the daylighting member are arranged opposite to the prescribed direction, the light is deflected by the light deflection element. It is set to an angle that does not totally reflect,
The manufacturing method of the opening structure with a lighting function of Claim 1. The predetermined angle is such that when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides of the daylighting member are disposed opposite to the prescribed direction, the light is deflected by the light deflection element. It is set to an angle that does not totally reflect,
The manufacturing method of the opening structure with a lighting function of Claim 1 or 2. The daylighting member includes a base formed in a sheet shape, and a plurality of the light deflection elements arranged in the sheet surface direction of the base,
The light deflection element is made of a material having a lower refractive index than the base,
The upper surface of the light deflection element is formed in a convex broken line shape or a curved shape toward the lower side in a longitudinal section along the thickness direction of the daylighting member,
The manufacturing method of the opening structure with a lighting function in any one of Claims 1 thru | or 3 with which the angle which the said upper surface forms with respect to the normal line direction of the said base is larger on the said surface side rather than the said back surface side. . The upper surface of the light deflection element is formed in a polygonal line shape in a longitudinal section along the thickness direction of the daylighting member,
The predetermined angle is such that when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides and the front and back of the daylighting member are arranged in the specified direction, the traveling direction of the light is the normal line. The angle formed with respect to the direction is set so that the plane portion closest to the surface side of the upper side surface is larger than the angle formed with respect to the normal direction.
The manufacturing method of the opening structure with a lighting function of Claim 4. The predetermined angle is obtained when light is incident on the surface from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the daylighting member are arranged in the specified direction. Set to be incident only on the plane portion closest to the surface side,
The manufacturing method of the opening structure with a lighting function of Claim 5. In a state where the upper and lower sides and the front and back sides are arranged in a prescribed direction, the optical deflection element includes a light deflection element that totally reflects light incident on the surface from a direction inclined at an angle within a design angle range, and is totally reflected by the light deflection element Preparing a daylighting member for emitting light from the back surface;
A direction discriminating step for discriminating at least one of upper and lower and front and back of the daylighting member;
A processing step for processing the daylighting member based on the determination result of the direction determination step,
With
In the direction discriminating step, test light is incident on the daylighting member from a direction inclined at a predetermined angle within the design angle range, and the upper and lower sides and the front and back sides of the daylighting member are based on the outgoing light emitted from the daylighting member. Determining at least one of the
A method for manufacturing a daylighting member. The predetermined angle is such that when light is incident on the back surface from a direction inclined upward in a state where the front and back of the daylighting member are arranged opposite to the prescribed direction, the light is deflected by the light deflection element. It is set to an angle that does not totally reflect,
The manufacturing method of the lighting member of Claim 7. The predetermined angle is such that when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides of the daylighting member are disposed opposite to the prescribed direction, the light is deflected by the light deflection element. It is set to an angle that does not totally reflect,
The manufacturing method of the lighting member of Claim 7 or 8. The daylighting member includes a base formed in a sheet shape, and a plurality of the light deflection elements arranged in the sheet surface direction of the base,
The light deflection element is made of a material having a lower refractive index than the base,
The upper surface of the light deflection element is formed in a convex broken line shape or a curved shape toward the lower side in a longitudinal section along the thickness direction of the daylighting member,
In the upper side, the angle formed with respect to the normal direction of the base is larger on the front side than on the back side.
The manufacturing method of the lighting member in any one of Claims 7 thru | or 9. The upper surface of the light deflection element is formed in a polygonal line shape in a longitudinal section along the thickness direction of the daylighting member,
The predetermined angle is such that when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides and the front and back of the daylighting member are arranged in the specified direction, the traveling direction of the light is the normal line. The angle formed with respect to the direction is set so that the plane portion closest to the surface side of the upper side surface is larger than the angle formed with respect to the normal direction.
The manufacturing method of the lighting member of Claim 10. The predetermined angle is obtained when light is incident on the surface from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the daylighting member are arranged in the specified direction. Set to be incident only on the plane portion closest to the surface side,
The manufacturing method of the lighting member of Claim 11. In the processing step, based on the determination result of the direction determination step, an indicator indicating the direction is provided on the daylighting member.
The manufacturing method of the lighting member in any one of Claims 7 thru | or 12. An indicator indicating a direction is provided in advance on the daylighting member,
In the processing step, based on the determination result of the direction determination step, the correctness of the index is confirmed, and when the direction indicated by the index is different from the actual direction of the daylighting member, the index is corrected.
The manufacturing method of the lighting member in any one of Claims 7 thru | or 12. In a state where the upper and lower sides and the front and back sides are arranged in a prescribed direction, the optical deflection element includes a light deflection element that totally reflects light incident on the surface from a direction inclined at an angle within a design angle range, and is totally reflected by the light deflection element Preparing a daylighting member for emitting light from the back surface;
A direction discriminating step for discriminating at least one of upper and lower and front and back of the daylighting member;
With
In the direction discriminating step, test light is incident on the daylighting member from a direction inclined at a predetermined angle within the design angle range, and the upper and lower sides and the front and back sides of the daylighting member are based on the outgoing light emitted from the daylighting member. Determining at least one of the
A method for determining the direction of a daylighting member. The predetermined angle is such that when light is incident on the back surface from a direction inclined upward in a state where the front and back of the daylighting member are arranged opposite to the prescribed direction, the light is deflected by the light deflection element. It is set to an angle that does not totally reflect,
The method for determining the direction of a daylighting member according to claim 15. The predetermined angle is determined by the light deflecting element when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides of the daylighting member are installed opposite to the prescribed direction. It is set to an angle that does not totally reflect,
The direction determination method of the lighting member according to claim 15 or 16. The daylighting member includes a base formed in a sheet shape, and a plurality of the light deflection elements arranged in the sheet surface direction of the base,
The light deflection element is made of a material having a lower refractive index than the base,
The upper surface of the light deflection element is formed in a convex broken line shape or a curved shape toward the lower side in a longitudinal section along the thickness direction of the daylighting member,
In the upper side, the angle formed with respect to the normal direction of the base is larger on the front side than on the back side.
The method for determining the direction of a daylighting member according to any one of claims 15 to 17. The upper surface of the light deflection element is formed in a polygonal line shape in a longitudinal section along the thickness direction of the daylighting member,
The predetermined angle is such that when light is incident on the surface from a direction inclined upward in a state where the upper and lower sides and the front and back of the daylighting member are arranged in the specified direction, the traveling direction of the light is the normal line. The angle formed with respect to the direction is set so that the plane portion closest to the surface side of the upper side surface is larger than the angle formed with respect to the normal direction.
The method for determining the direction of a daylighting member according to claim 18. The predetermined angle is obtained when light is incident on the surface from a direction inclined upward in a state where the upper and lower surfaces and the front and back surfaces of the daylighting member are arranged in the specified direction. Set to be incident only on the plane portion closest to the surface side,
The lighting member direction discriminating method according to claim 19.

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