Patent Grant
10520151
This application is the U.S. national phase of International Application No. PCT/JP2015/079984 filed Oct. 23, 2015, which designated the U.S. and claims priority to Japanese Patent Application No. JP 2014-217261 filed Oct. 24, 2014, the entire contents of each of which are hereby incorporated by reference.
The present invention relates to a daylighting apparatus.
The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2014-217261 filed in the Japan Patent Office on Oct. 24, 2014, the entire contents of which are hereby incorporated by reference.
PTL 1 proposes a daylighting panel for letting sunlight into a room through a window or the like of a building. This daylighting panel includes: a panel; a substrate layer formed on one surface of the panel; a plurality of unit prisms having trapezoidal cross-sections; and a protective layer covering the plurality of unit prisms.
Sunlight is let into the room by passing through the substrate layer, the unit prisms, and the protective layer in sequence.
PTL 1: Japanese Unexamined Patent Application Publication No. 2013-156554
The daylighting apparatus can be an exterior component to the eyes of a person who looks at the building from the outside, as the daylighting apparatus is installed by the window. For example, a building that appears bright as a whole has an advantage of conveying a higher sense of luxuriousness. However, while the daylighting apparatus, which has high daylighting performance, efficiently introduces outside light into the room and therefore imparts brightness to the inside of the room, the daylighting apparatus has the action of making the place of its installation appear dark when the building is looked at from the outside. This causes the building to lose the sense of luxuriousness, causes the apparatus to be less expressive in appearance, causes a person who looks at the building from the outside to feel a sense of incongruity because of disharmony with other bright exterior parts, and causes other similar problems.
An aspect of the present invention is a daylighting apparatus that can make the place of its installation appear bright.
A daylighting apparatus according to an aspect of the present invention includes: a daylighting member that has first and second surfaces opposite to each other and that lets light in through the first surface and lets the light out through the second surface at a predetermined distribution of angles; and a reflecting member that reflects part of visible light falling on the first surface of the daylighting member.
In the daylighting apparatus according to the aspect of the present invention, the reflecting member may be provided in at least part of a plane facing the first surface of the daylighting member.
In the daylighting apparatus according to the aspect of the present invention, the reflecting member may further have a function of transmitting the visible light.
In the daylighting apparatus according to the aspect of the present invention, the reflecting member may have a reflectance that periodically varies in one in-plane direction.
In the daylighting apparatus according to the aspect of the present invention, the daylighting member may include a first substrate, a plurality of daylighting portions arrayed in one direction on a first surface of the first substrate, and a void part provided between each of the daylighting portions and the other, and there may be a coincidence between the direction in which the reflectance of the reflecting member periodically varies and the direction in which the plurality of daylighting portions are arrayed.
In the daylighting apparatus according to the aspect of the present invention, the reflecting member may include a reflecting portion that reflects the visible light and a transmitting portion that transmits the visible light.
In the daylighting apparatus according to the aspect of the present invention, the reflecting member may include a visible light-transmitting substrate and a plurality of reflecting portions provided all over the visible light-transmitting substrate.
In the daylighting apparatus according to the aspect of the present invention, the plurality of reflecting portions may be constituted by reflective ink printed all over the visible light-transmitting substrate.
In a daylighting apparatus according to an aspect of the present invention, the reflecting member may include a visible light-reflecting substrate and a plurality of transmitting portions provided in the visible light-reflecting substrate.
In the daylighting apparatus according to the aspect of the present invention, the plurality of transmitting portions may be constituted by a plurality of through-holes provided in the visible light-reflecting substrate.
In the daylighting apparatus according to the aspect of the present invention, the reflecting member may be constituted by a semi-transmissive member that reflects part of the visible light and transmits part of the visible light.
In the daylighting apparatus according to the aspect of the present invention, the reflecting member may be provided in contact with the first surface of the daylighting member.
The daylighting apparatus according to the aspect of the present invention may further include a frame that houses the daylighting member and the reflecting member.
The daylighting apparatus according to the aspect of the present invention may further include a light-diffusing member, provided toward the second surface of the daylighting member, which diffuses the light having exited through the second surface.
An aspect of the present invention makes it possible to achieve a daylighting apparatus that can make the place of its installation appear bright.
A first embodiment of the present invention is described below with reference to
A daylighting apparatus of the present embodiment is one that is installed, for example, on a part of a window of an office building to let sunlight into a room.
It should be noted that, to facilitate visualization of each constituent element, each of the following drawings may illustrate some constituent elements on different dimension scales.
As shown in
As shown in
The plurality of glass plates and the sheets are placed so that the first glass plate 10, the light-diffusing sheet 11, the second glass plate 12, the daylighting sheet 13, the visible light-reflecting sheet 15, and the third glass plates 14 are arranged in this order from the inside of the room toward the outside of the building. The visible light-reflecting sheet 15 is provided in at least part of a plane facing the first surface 13a of the daylighting sheet 13. That is, of the sheets, the visible light-reflecting sheet 15 is placed closest to the outside of the building. This allows an observer who is outside of the window to see the visible light-reflecting sheet 15 by receiving reflected light from the visible light-reflecting sheet 15.
The daylighting sheet 13 of the present embodiment corresponds to the daylighting member of the claims. The visible light-reflecting sheet 15 of the present embodiment corresponds to the reflecting member of the claims. The light-diffusing sheet 11 of the present embodiment corresponds to the light-diffusing member of the claims.
For convenience of explanation, an indoor-side surface of each of the glass plates is hereinafter referred to as “first surface”, and an outdoor-side surface of each of the glass plates is hereinafter referred to as “second surface”.
The light-diffusing sheet 11 is bonded to a second surface 10b of the first glass plate 10. The daylighting sheet 13 is bonded to a second surface 12b of the second glass plate 12. The visible light-reflecting sheet 15 is bonded to a first surface 14a of the third glass plate 14. The first, second, and third glass plates 10, 12, and 14 are glass plates, approximately 3 to 6 mm in thickness, bonded to each other using the adhesive material 18 with spaces therebetween.
The frame 16, which is made of a material such as aluminum or resin, covers the edges of a laminate formed by stacking the three glass plates 10, 12, and 14. Therefore, the frame 16 houses the three glass plates 10, 12, and 14 with the aforementioned sheets respectively bonded thereto. The cushioning material 17, which is made, for example, of rubber, is provided between end faces of the laminate and the frame 16. Furthermore, the caulking material 19, which is for example a silicone caulking material, fills the space between the edges of the laminate and the frame 16.
As shown in
As the film substrate 41, an optical transparent substrate containing a resin such as a thermoplastic polymer, a thermosetting resin, or a photopolymerizable resin is used. An optically transparent substrate of an acrylic polymer, an olefinic polymer, a vinyl polymer, a cellulose polymer, an amide polymer, a fluorinated polymer, a urethane polymer, a silicone polymer, an imide polymer, or the like is used. Specifically, an optically transparent substrate such as a triacetyl cellulose (TAC) film, a polyethylene terephthalate (PET) film, a cycloolefin polymer (COP) film, a polycarbonate (PC) film, a polyethylene naphthalate (PEN) film, a polyether sulfone (PES) film, or a polyimide (PI) film is preferably used. In the present embodiment, as an example, a PET film having a thickness of 100 μm is used. It is preferable that the film substrate 41 have a total light transmittance of, for example, 90% or higher.
This gives sufficient transparency.
The daylighting portions 42 are made of an optically transparent and photosensitive organic material such as acrylic resin, epoxy resin, or silicone resin. A transparent resin mixture obtained by mixing a polymerization initiator, a coupling agent, a monomer, an organic solvent, and the like into this resin is used. Furthermore, the polymerization initiator may contain various types of additional component such as a stabilizer, an inhibitor, a plasticizer, a fluorescent brightening agent, a mold release agent, a chain transfer agent, and another photopolymerizable monomer. In the present embodiment, the daylighting portions 42 are made, for example, of polymethylmethacrylate (PMMA). It is preferable that the daylighting portions 42 have a total light transmittance of 90% or higher under JIS K7361-1. This gives sufficient transparency.
In the present embodiment, the plurality of daylighting portions 42 are formed on the film substrate 41 by a thermal imprinting method. The daylighting portions 42 may be formed by a method other than the thermal imprinting method, such as a UV imprinting method, a thermal pressing method, an injection molding method, an extrusion molding method, or a compression molding method. In a method such as a melt extrusion method or a mold extrusion method, the film substrate 41 and the daylighting portions 42 are integrally formed by the same resin. Alternatively, a shape-transferring (UV transfer/thermal transfer) resin applied onto a base film of PET or the like may be molded into a structure by imprinting.
The refractive index of each of the daylighting portions 42 takes on a value of approximately 1.5. The present embodiment encompasses the range of approximately 1.35, which is a refractive index in the case of mixture of fluorinated additives into the chief material, to 1.6, which is a refractive index in the case of mixture of a conjugated composition of allyl groups or the like into the chief material, and each of the daylighting portions 42 has a refractive index falling within the range.
Each of the daylighting portions 42 stretches out long and thin in a linear fashion in one direction (i.e. the Y direction of
The first and second vertices q1 and q2 of the hexagonal cross-sectional shape of each of the daylighting portions 42 correspond to both ends of a first side 42A of the daylighting portion 42 that touches the film substrate 41. The fourth, fifth, and sixth vertices q4, q5, and q6 are not located on the first side 42A. The third vertex q3 is farthest away from the first surface 42A. The length of a perpendicular line through the third vertex q3 to the first side 42A is greater than the length of a perpendicular line through any of the vertices q1 to q6 other than the third vertex q3 to the first side 42A. The shape of each of the daylighting portions 42 is asymmetrical with respect to the perpendicular line through the third vertex q3 to the first side 42A.
It should be noted that the shape of each of the daylighting portions 42 is not limited to the aforementioned shape but may be polygonal, trapezoidal, or triangular in cross-section orthogonal to the longitudinal direction.
As shown in
In a state where the daylighting apparatus 2 has been installed on the window 1, the daylighting sheet 13 is installed in such a posture that second and third surfaces 42B and 42C of the hexagonal cross-sectional shape of each of the daylighting portions 42 face upward in the vertical direction and fourth, fifth, and sixth surfaces 42D, 42E, and 42F of the hexagonal cross-sectional shape of each of the daylighting portions 42 face downward in the vertical direction.
It is desirable that the film substrate 41 and the daylighting portions 42 be substantially equal in refractive index to each other. A reason for this is as follows: For example, in a case where the film substrate 41 and the daylighting portions 42 are greatly different in refractive index from each other, light having entered the film substrate 41 from the daylighting portions 42 may unnecessarily become refracted or reflected at the interface between the daylighting portions 42 and the film substrate 41, and in this case, there may occur problems such as the failure to achieve the desired daylighting properties and a decrease in luminance.
Air is present in the void part 43. Therefore, the void part 43 has a refractive index of approximately 1.0. The refractive index of 1.0 of the void part 43 minimizes a critical angle at an interface (air interface) 42c between the void part 43 and a daylighting portion 42.
The light-diffusing sheet 11 is anisotropic in direction of diffusion of light and has the property of diffusing light more strongly in the horizontal direction (Y direction) than in the vertical direction (Z direction). As shown in
Each of the convex lens components 32 has a convex surface 32a that has a curvature in a horizontal plane but does not have a curvature in a vertical plane. Therefore, the convex lens components 32 have high light diffusion properties in the horizontal direction (Y direction) but do not have light diffusion properties in the vertical direction (Z direction). This causes light having entered the light-diffusing sheet 11 to exit from the convex lens components 32 while being greatly diffused in the horizontal direction (Y direction) but almost without being diffused in the vertical direction (Z direction). It should be noted that
The convex lens components 32 may be ones integrated with the substrate 31 by processing the second surface 31b of the substrate 31 per se or may be ones that are separate from the substrate 31. The light-diffusing sheet 11 does not need to have a regular structure such as a lenticular lens structure but may include a plurality of irregularly-provided projections. Alternatively, the light-diffusing sheet 11 may be one that includes an optically transparent resin layer that serves as a medium and a plurality of fibrous or elliptical light-diffusing particles dispersed in the optically transparent resin layer so that the light-diffusing particles align themselves in the horizontal direction.
In the present embodiment, the light-diffusing sheet 11 used has the anisotropy to diffuse light more strongly in the horizontal direction (Y direction) than in the vertical direction (Z direction). This makes it possible to reduce glare and, at the same time, achieve an average brightness regardless of the azimuth of the sun. However, in some cases, a light-diffusing sheet may be used which has the anisotropy to diffuse light more strongly in the vertical direction (Z direction). This makes it possible to reduce nonuniformity in brightness in a depth direction of the room. Alternatively, a light-diffusing sheet may be used which diffuses light isotropically.
The visible light-reflecting sheet includes a reflecting portion that reflects visible light and a transmitting portion that transmits visible light. This allows the visible light-reflecting sheet to a function of reflecting part of visible light coming from the outside and transmitting part of the visible light.
As shown in
The resin films 53 and 56 are constituted, for example, by resin films of polyester or the like. The adhesive material layers 52 and 55 are made of an optically transparent adhesive material having ultraviolet absorptivity. The hard coating layer 57 is provided to impart abrasion resistance to the laminate located therebelow and has high hardness and transparency.
The visible light-reflecting layer 54 of the present embodiment corresponds to the reflecting portions of the claims.
The plurality of patterns of the visible light-reflecting layer 54 are printed on the resin film 53. Although not shown in
Note, however, that the visible light-reflecting layer 54 does not necessarily need to be white but may for example be beige or light gray to match the color of the exterior of the building or the color of the blind. That is, the visible light-reflecting layer 54 is constituted by reflective ink printed all over the substrate 51.
As shown in
The patterns 54a range, for example, from approximately 15 μm to 1.5 mm in diameter and so sized that an observer several meters away cannot recognize each separate pattern.
In general, visual acuity is expressed as the reciprocal of a visual angle expressed in units of 1 minute, which is one sixtieth of 1 degree. Specifically, the angle formed by the gap of a Landolt ring used for testing vision and the center of an eye is the visual angle, and the reciprocal of the visual angle is the visual acuity. A “visual acuity of 1.0” is defined in Japan as the ability to, when viewing, from 5 m away, a Landolt ring made by making a gap 1.5 mm in width in a part of a circle 7.5 mm in diameter and 1.5 mm in thickness, accurately decide on which direction the gap faces in. Judging from these discussions on Landolt rings, an observer 5 m away with ordinary visual acuity cannot recognize each separate pattern 54a, provided the pattern is 1.5 mm or smaller. The plurality of patterns 54a as a whole are recognized by an observer as a pattern of light and dark corresponding to the density of the patterns 54a. On the other hand, the lower limit of 15 μm is determined by the capacity of a printing apparatus. Currently, a common printing apparatus has a printing capacity of approximately several tens of micrometers.
The plurality of circular patterns 54a of the visible light-reflecting layer 54 are regularly arranged in each unit region Ta. Those of the patterns 54a which are in a lower part of the unit region Ta are larger, and those of the patterns 54a which are in an upper part of the unit region Ta are smaller. Therefore, the percentage of areas occupied by patterns 54a per unit area becomes higher toward the lower part of the unit region Ta and becomes lower toward the upper part of the unit region Ta. The visible light-reflecting layer 54 reflects light having fallen on the patterns 54a (i.e. the white parts of
In other words, the light reflectance becomes higher toward the lower part of the unit region Ta and becomes lower toward the upper part of the unit region Ta. The visible light-reflecting sheet 15 as a whole has a configuration of repetition of unit regions Ta having such an arrangement of patterns. For this reason, the reflectance of the visible light-reflecting sheet 15 periodically varies in one in-plane direction.
A method for manufacturing a daylighting apparatus 2 configured as described above is described below with reference to
In manufacturing a daylighting apparatus, a first glass plate 10 with a light-diffusing sheet 11 bonded thereto, a second glass plate 12 with a daylighting sheet 13 bonded thereto, and a third glass plate 14 with a visible light-reflecting sheet 15 bonded thereto are prepared. Illustration of these sheets is omitted. These sheets may be bonded to the respective glass plates 10, 12, 14, for example, by dry bonding using an acrylic adhesive material or by water bonding using a water-bonding adhesive material with fine adjustments of the bonding positions.
Next, as shown in
Next, as shown in
Next, as shown in
The action of the daylighting apparatus 2 of the present embodiment is described with reference to
For convenience of explanation, let it be assumed that the point of incidence G is a point at which a given beam of light having entered a daylighting portion 42 shown in
As shown in
The light L3 diffused by the light-diffusing sheet 11 turns into light that travels toward the ceiling and illuminates a wide range in the depth direction of the room. Therefore, the daylighting apparatus 2 allows outside light (sunlight) let in to be efficiently guided toward the ceiling of the room. This makes it possible to make the room bright without causing a person who is in the room to feel dazzled.
It should be noted that the aforementioned optical path is a mere example and outside light having entered the daylighting apparatus 2 falls on either of the second and third surfaces 42B and 42C of each of the daylighting portions 42 of the daylighting sheet 13. This light exits through the first surface 42A after being reflected by any of the fourth, fifth, and sixth surfaces 42D, 42E, and 42F. Thus, there are several optical paths of light passing through the daylighting portions 42.
As shown in
Thus, there is a coincidence between the direction in which the reflectance of the visible light-reflecting sheet 15 periodically varies and the direction in which the plurality of slats 5 are arrayed. This causes the observer to see horizontal stripes of substantially the same width both in the place of installation of the daylighting apparatus 2 and the place of installation of the blind 3 when looking at the window 1 from outside of the building. Thus, the daylighting apparatus 2 of the present embodiment can achieve such an appearance as to give a sense of unity with the blind located therebelow.
The inventors of the present invention actually fabricated a daylighting apparatus of the present embodiment, installed it on a window, and checked the appearance of it.
In
In the region A21, where no daylighting apparatus was installed, light was let into the room through the window, and very little light was reflected toward the outside; therefore, this part appeared much darker in appearance than the regions A11 and A12, in which the blinds were installed. On the other hand, in the region A22, where the daylighting apparatus of the present embodiment was installed, the action of the visible light-reflecting sheet gave a high-reflectance pattern of horizontal stripes; as a result, this part was similar in appearance to the regions A11 and A12, in which the blinds were installed. It was therefore confirmed that a sense of unity was given as if the whole window had been provided with a uniform blind.
In the present embodiment, although the visible light-reflecting sheet 15 is formed by high-reflectance white ink, the color of the ink is not limited to white. For example, the color of the ink may be high-brightness light gray or pale blue or green, which matches the color of the interior or exterior. Note, however, that it is desirable that the visible light-reflecting sheet 15 have a reflectance of a certain value or higher, e.g. a visible light reflectance (Y value) of 60% or higher. A reason for this is that a sense of unity with the exterior can be given by the visible light-reflecting sheet 15 reflecting outside light and exhibiting a reflectance which is equal to that of the exterior such as the outside walls of the building. It should be noted that, instead of including the visible light-reflecting layer, the visible light-reflecting sheet may include a metal thin-film pattern formed by vapor evaporation or by sputtering and etching or may include a metal thin-film pattern formed by mask vapor deposition.
In the present embodiment, since the portions of the visible light-reflecting layer 54 that serve as the patterns 54a hardly transmit light into the room, there is a decrease in daylighting performance according to the area covered by the visible light-reflecting layer 54.
Therefore, the area of the region in which the patterns 54a are formed cannot be made larger than is necessary. It is desirable that the area of a pattern-forming region of the visible light-reflecting layer 54 be approximately 5 to 50% of the whole area of the visible light-reflecting layer 54. The area of the pattern-forming region needs only be appropriately determined according to which of various parameters has priority. The various parameters include the orientation of the window, the location of the building, the transmittance of the window outside of the daylighting apparatus, the reflectance of the exterior, fastidiousness with exterior design, and the like.
A second embodiment of the present invention is described below with reference to
A daylighting apparatus of the present embodiment is identical in basic configuration to that of the first embodiment but differs from that of the first embodiment in terms of the placement of the visible light-reflecting sheet.
Constituent elements shown in
In the first embodiment, the daylighting apparatus includes the third glass plate, and the visible light-reflecting sheet is bonded to the third glass plate. On the other hand, as shown in
As with the first embodiment, the present embodiment brings about an effect of making it possible to achieve a daylighting apparatus that gives a sense of unity to the appearance of a window with a blind installed thereon. Furthermore, the present embodiment needs only two glass plates to constitute the daylighting apparatus 61, thus making it possible to achieve reductions in weight, thickness, and cost of daylighting apparatuses.
A third embodiment of the present invention is described below with reference to
A daylighting apparatus of the present embodiment is identical in basic configuration to that of the first embodiment but differs from that of the first embodiment in terms of the configuration of a visible light-reflecting portion.
Constituent elements shown in
In the first embodiment, the daylighting apparatus includes the third glass plate, and the visible light-reflecting sheet is bonded to the third glass plate. On the other hand, as shown in
As with the first and second embodiments, the present embodiment brings about an effect of making it possible to achieve a daylighting apparatus that gives a sense of unity to the appearance of a window with a blind installed thereon. Furthermore, the present embodiment needs only two glass plates to constitute the daylighting apparatus 64, thus making it possible to achieve reductions in weight, thickness, and cost of daylighting apparatuses.
A fourth embodiment of the present invention is described below with reference to
A daylighting apparatus of the present embodiment is identical in basic configuration to that of the first embodiment but differs from that of the first embodiment in terms of the configuration of a visible light-reflecting portion.
Constituent elements shown in
In the third embodiment, the patterns of the visible light-reflecting layer are provided so as to cover the plurality of daylighting portions. On the other hand, as shown in
As with the first to third embodiments, the present embodiment brings about an effect of making it possible to achieve a daylighting apparatus that gives a sense of unity to the appearance of a window with a blind installed thereon. Furthermore, the present embodiment needs only two glass plates to constitute the daylighting apparatus 67, thus making it possible to achieve reductions in weight, thickness, and cost of daylighting apparatuses.
The inventors of the present invention actually fabricated a daylighting apparatus including a visible light-reflecting sheet and evaluated the optical properties of the daylighting apparatus. The following shows the results of the evaluation.
The inventors of the present invention fabricated a visible light-reflecting sheet having printed patterns 72 such as those shown in
Let it be assumed here that a 20-mm-wide unit region Ta is divided into twenty smaller 2-mm-wide reed-shaped regions staggered 1 mm apart in the direction of increase and decrease in density of the printed patterns 72. These twenty smaller regions were numbered 1, 2, 3, . . . , and 20, respectively, in descending order of gross area of printed patterns 72 (from the left to the right in
It was found that carrying out the design of drawing a substantially smooth curve in the width W of 20 mm in the graph of
The inventors of the present invention fabricated four types of visible light-reflecting sheet under different specifications and evaluated the optical properties of the visible light-reflecting sheets.
The visible light-reflecting sheet of Example 1 has white printed patterns formed by a gravure printing method, and the percentages of areas occupied by the printed patterns in the whole visible light-reflecting sheet is 50.0%.
The visible light-reflecting sheet of Example 2 has white printed patterns formed by a UV inkjet method, and the percentages of areas occupied by the printed patterns in the whole visible light-reflecting sheet is approximately 16%.
The visible light-reflecting sheet of Example 3 has printed patterns formed by mixed ink of white (W) and cyan (C) by the UV inkjet method, and the percentages of areas occupied by the printed patterns in the whole visible light-reflecting sheet is approximately 13%.
The visible light-reflecting sheet of Example 4 has printed patterns formed by mixed ink of white (W) and magenta (M) by the UV inkjet method, and the percentages of areas occupied by the printed patterns in the whole visible light-reflecting sheet is approximately 10%.
Items of evaluation of a single printed portion having printed patterns formed thereon include total light transmittance, total light reflectance, absorptance, and rectilinear transmittance. The results of evaluation of these items are shown in [Table 1].
It should be noted that, in the column “Printed Color” of Table 1, W100 represents printing in solid white (with a grayscale of 100%). W100+C10 represents printing in solid white with cyan added thereto with a grayscale of 10%. In this case, the printed patterns exhibit slightly-cyanic white. Similarly, W100+M10 represents printing in solid white with magenta added thereto with a grayscale of 10%.
In this case, the printed patterns exhibit slightly-magenta white.
As shown in
As shown in
The absorptance Ta was calculated using the total light transmittance Tt and the total light reflectance Tr according to equation (1):
Ta=1−(Tt+Tr) (1)
As shown in
The visible light-reflecting sheet 80 includes a printed portion and a non-printed portion (transparent portion). Therefore, the performance of the visible light-reflecting sheet 80 is determined by the optical properties of the printed portion, the optical properties of the transparent portion, and the percentages of areas occupied by the printed portion and the transparent portion. [Table 1] above shows the optical properties of the printed portion, which function as a reflecting layer. In a case where a visible light-reflecting sheet is used, consideration should be given to the “daylighting component”, the “scatter component”, and the “reflection component”, which will be described later, and these components serve as indices of daylighting performance, non-design element, and appearance reflectance, respectively. The results of measurement of the total light transmittance Tt, total light reflectance Tr, rectilinear transmittance, reflected colors L*a*b* of each of the examples as the optical properties of the sheet in association with these indices are tabulated in [Table 1].
As a visible light-reflecting sheet having such properties, a transparent film with printed patterns formed thereon was used. The printed patterns took the form of a striped gradation of white patterns. Each of the horizontal stripes was 20 mm in width. The printed patterns were formed by the gravure printing method or the UV inkjet method. The color in which the patterns were printed was a mixture of white and cyan (C) or a mixture of white and magenta (M), as well as white. This makes it possible to give a sense of unity as a tint with the exterior of the building and to impart design. For example, as in Examples 3 and 4, the yellowish tint of the UV cut layer of the daylighting apparatus or the greenish tint of the double-glazed glass can be cancelled out by printing white with slight coloring added thereto. As a result, the printed white can appear more whitish when viewed from outside of the window.
Next, items of evaluation of the whole visible light-reflecting sheet integrating a printed portion and a non-printed portion (transparent portion) include the aforementioned daylighting component, scatter component, and reflection component.
The results of evaluation of these items are shown in [Table 2].
The daylighting component was calculated according to equation (2):
Daylighting Component=Rectilinear Transmittance of Printed Portion×Percentage of Areas Occupied by Printed Portion+Rectilinear Transmittance of Transparent Portion×Percentage of Areas Occupied by Transparent Portion (2)
The daylighting component serves as an index of the daylighting performance of a daylighting sheet with a visible light-reflecting sheet stacked thereon. The closer the value of the daylighting component is to 100%, the more the daylighting sheet can exert its original daylighting performance.
The scatter component was calculated according to equation (3):
Scatter Component=Total Light Transmittance of Printed Portion×Percentage of Areas Occupied by Printed Portion (3)
The scatter component serves as an index of a so-called non-design component, i.e. a component that, in the case of a daylighting sheet with a visible light-reflecting sheet stacked thereon, is not taken into consideration when outside light falls on the visible light-reflecting sheet alone. The smaller the value of the scatter component is, the more the daylighting sheet can exert its daylighting performance as designed.
The reflection component was calculated according to equation (4):
Reflection Component=Total Light Reflectance of Printed Portion×Percentage of Areas Occupied by Printed Portion (4)
The reflection component serves as an index of the appearance reflectance of a daylighting sheet with a visible light-reflecting sheet stacked thereon. The larger the value of the reflection component is, the brighter the appearance is and the easier it is to give a sense of unity with the exterior of the building.
For each of the visible light-reflecting sheets of Examples 1 to 4, a tabulation of details of the performance of the printed portion, the performance of the non-printed portion (transmitting portion), and the performance of the sheet as a whole is shown in [Table 3].
Further, the inventors of the present invention measured the intensity of light scattered and transmitted through the visible light-reflecting sheets of Examples 2 to 4, with variations in the angle θ of the light receiver 85 of the angular luminance meter 86 shown in
In
As mentioned above, light scattered and transmitted through a visible light-reflecting sheet turns into a non-design element for the daylighting apparatus. Further, unlike light that travels toward a ceiling, such light may undesirably turn into light (glare light) that causes a person who is in the room to feel dazzled. For that reason, it is desirable that the printed portion be low in diffuse transmittance. In that respect, the diffuse transmission properties of the printed portions of the visible light-reflecting sheets of Examples 2 to 4 were as shown in
A fifth embodiment of the present invention is described below with reference to
A daylighting apparatus of the present embodiment is identical in basic configuration to that of the first embodiment but differs from that of the first embodiment in terms of the configuration of a visible light-reflecting sheet.
Constituent elements shown in
As shown in
As shown in
In the first embodiment, the portions of the visible light-reflecting sheet that serve as the printed patterns mainly reflect light, and the portion of the visible light-reflecting sheet other than the printed patterns mainly transmits light. In the fifth embodiment, on the other hand, the visible light-reflecting sheets 91 are uniform in reflection properties and transmission properties of light throughout the whole surface. That is, the visible light-reflection sheets 91 are so-called semitransparent mirror sheets, i.e. semi-transmissive members that reflect and transmit light in definite proportions throughout the whose surface.
Each of the visible light-reflecting sheets 91 is constituted, for example, by a dielectric multilayer or a metal film of aluminum, silver, or the like.
This allows the visible light-reflecting sheet 91 to function as a so-called selective transmitting/selective reflecting film, i.e. a film that splits the wavelength range (380 to 780 nm) of visible light La into particular wavelength ranges and emit reflected lights Lb, Lc, Ld, and Le. By thus uniformly transmitting the visible wavelength range of light, requirements for daylighting apparatuses intended to utilize natural light for daytime illumination can be satisfied. Further, part of light is reflected by the whole surface of the visible light-reflecting sheet 91, higher daylighting efficiency can be maintained than in a case where the visible light-reflecting sheet of the first embodiment is used. This makes it possible to provide visible light-reflecting sheets 91 over a wider range in the daylighting apparatus 90.
The reflectance of the daylighting apparatus 90 as a whole can be adjusted by the reflectance of the visible light-reflecting sheets 91 and the area of installation of the visible light-reflecting sheets 91. It is desirable that the reflectance of the daylighting apparatus 90 as a whole range from 30 to 70%. Further, in the case of the present embodiment, where the visible light-reflecting sheets 91 are placed toward the side of the daylighting sheet 13 through which light exits, it is desirable that the visible light-reflecting sheets 91 have the property of preventing diffusion of light having exited from the daylighting sheet 13. In this case, light having entered the visible light-reflecting sheets 91 is reflected, transmitted, or absorbed. This makes it possible to prevent the light from turning into glare light by changing its traveling direction through the visible light-reflecting sheets 91 and entering the room.
The inventors of the present invention actually fabricated a daylighting apparatus of the fifth embodiment, installed it on a window, and checked the appearance of it.
In
In the region A2, where the daylighting apparatus of the fifth embodiment was installed, the action of the visible light-reflecting sheet gave a high-reflectance pattern of horizontal stripes; as a result, this part was similar in appearance to the region A1, in which the blind was installed. It was therefore confirmed that a sense of unity was given as if the whole window had been provided with a uniform blind.
The inventors of the present invention actually fabricated daylighting apparatuses including visible light-reflecting sheets shown in
In this evaluation, the visible light-reflecting sheets had different reflectances R of 70%, 50%, and 20%, and the width H of each visible light-reflecting sheet and the spacing B between adjacent visible light-reflecting sheets were varied as shown in [Table 4].
In Example 5, the visible light-reflecting sheets had a reflectance R of 70%. In Example 5, the width H of each visible light-reflecting sheet was 20 mm, and the spacing B between adjacent visible light-reflecting sheets was 20 mm.
In Example 6, the visible light-reflecting sheets had a reflectance R of 50%. In Example 6, the width H of each visible light-reflecting sheet was 10 mm, and the spacing B between adjacent visible light-reflecting sheets was 10 mm.
In Example 7, the visible light-reflecting sheets had a reflectance R of 20%. In Example 7, the width H of each visible light-reflecting sheet was 20 mm, and the spacing B between adjacent visible light-reflecting sheets was 5 mm.
The visible light-reflecting sheet of Example 8 had a reflectance R of 20% and was shaped to cover the whole surface of the second glass plate.
The visible light-reflecting sheets with reflectances R of 70%, 50%, and 20% have, for example, spectral reflectance properties shown in
As shown in [Table 4], for example in the case of Example 5, the proportion of the area of the portions covered by the visible light-reflecting sheets to the whole area of the second glass plate, i.e. the sheet coverage S, is 50%.
Defining Reflectance R×Coverage S as an index of reflection intensity, R×S=35%.
The other embodiments apply numerical values such as those shown in [Table 4]. In the case of a visible light-reflecting sheet having a low reflectance, it is preferable that the sheet coverage be high. For example, the sheet coverage may be 80%, or as in Example 8, the sheet coverage may be 100%. In a case where the sheet coverage is 100%, the step of making slits in a visible light-reflecting sheet and the subsequent step can be omitted from the after-mentioned process for manufacturing visible light-reflecting sheets. However, in a case where the sheet coverage is 100%, it is difficult to impart a sense of stripes, although a bright appearance can be achieved.
[Manufacturing Method]
A method for manufacturing a daylighting apparatus 90 of the fifth embodiment, particularly a method for manufacturing a second glass plate 12 with visible light-reflecting sheets 91 bonded thereto, is described below with reference to
First, as shown in
Next, as shown in
Next, as shown in
Next, as shown in
Further, a daylighting sheet 13 is bonded to a surface of the second glass plate 12 opposite to a surface of the second glass plate 12 on which the visible light-reflecting sheets 91 are provided. The step of bonding the daylighting sheet 13 may precede or follow the step of bonding the visible light-reflecting sheets 91.
In terms of the process of assembling the other constituent elements, the fifth embodiment is identical to the first embodiment.
As with the first to fourth embodiments, the present embodiment brings about an effect of making it possible to achieve a daylighting apparatus that gives a sense of unity to the appearance of a window with a blind installed thereon.
[First Modification of Visible Light-Reflecting Sheet]
Although the first to fifth embodiments have been described above by taking an example in which the visible light-reflecting sheet(s) impart(s) a pattern of stripes to the appearance of the daylighting apparatus, such a pattern of stripes is not a must.
As shown in
[Second Modification of Visible Light-Reflecting Sheet]
As shown in
A daylighting apparatus including a visible light-reflecting sheet 94 or 97 of the first or second modification can provide a bright appearance when seen from outside of the window. This makes it possible to impart advertising effectiveness or design qualities to the window, although it is difficult, unlike in the first to fifth embodiment, to give a sense of unity with a blind by imparting a pattern of stripes to the appearance of the daylighting apparatus.
A sixth embodiment of the present invention is described below with reference to
A daylighting apparatus of the present embodiment is identical in basic configuration to that of the first embodiment but differs from that of the first embodiment in terms of the configuration of a visible light-reflecting sheet.
Constituent elements shown in
As shown in
As shown in
As with the first to fifth embodiments, the present embodiment brings about an effect of making it possible to achieve a daylighting apparatus that gives a sense of unity to the appearance of a window with a blind installed thereon.
A seventh embodiment of the present invention is described below with reference to
A daylighting apparatus of the present embodiment is identical in basic configuration to that of the first embodiment but differs from that of the first embodiment in terms of the configuration of a reflecting member.
Constituent elements shown in
In the first to sixth embodiments, all reflecting members are in sheet form. On the other hand, as shown in
As with the first to sixth embodiments, the present embodiment brings about an effect of making it possible to achieve a daylighting apparatus that gives a sense of unity to the appearance of a window with a blind installed thereon.
[Illumination Lighting Control System]
In the room model 2000, a room 2003 into which outside light is introduced may have a ceiling 2003a constituted by a ceiling material having high light reflectivity. As shown in
As mentioned earlier, the light reflective ceiling material 2003A functions to effectively guide, into the back of the room, the outside light introduced into the room through the window 2002 on which the daylighting apparatus 2010 of the present invention (i.e. the daylighting apparatus according to any of the embodiments described above) is installed. The outside light introduced from the daylighting apparatus 2010 toward the ceiling 2003a inside the room is reflected by the light reflective ceiling material 2003A, changes its direction, and illuminates a desk top surface 2005a of a desk 2005 put in the back of the room, thus bringing about an effect of brightening up the desk top surface 2005a.
The light reflective ceiling material 2003A may be a diffuse reflective material or a specular reflective material. However, in order to bring about both an effect of brightening up the desk top surface 2005a of the desk 2005 put in the back of the room and an effect of reducing the glare that is unpleasant to a person who is in the room, it is preferable that the light reflective ceiling material 2003A possess an appropriate mixture of the properties of both a diffuse reflective material and a specular reflective material.
Although much of the light introduced into the room by the daylighting apparatus 2010 travels toward the ceiling near the window 2002, the amount of light is often sufficient in the vicinity of the window 2002. For this reason, combined use of such a light reflective ceiling material 2003A diverts the light having fallen on the ceiling (region E) near the window into the back of the room, where the amount of light is smaller than it is by the window.
The light reflective ceiling material 2003A may be prepared either by embossing a metal plate of aluminum or the like so that the metal plate has depressed and raised portions on the order of several tens of micrometers or by depositing a metal thin film of aluminum or the like on a surface of a similarly embossed resin substrate. Alternatively, the depressed and raised portions that are formed by the embossing may be formed by curved surfaces at larger intervals.
Furthermore, the distribution property of light and the distribution of light inside the room can be controlled by appropriately changing the embossed shapes that are formed in the light reflective ceiling material 2003A. For example, in the case of embossing in stripes that extend into the back of the room, light reflected by the light reflective ceiling material 2003A spreads in a transverse direction of the window 2002 (i.e. a direction intersecting a longitudinal direction of the depressed and raise portions). In a case where the window 2002 of the room 2003 is limited in size and orientation, such properties are utilized so that the light reflective ceiling material 2003A can diffuse the light in a horizontal direction and reflect the light toward the back of the room.
The daylighting apparatus 2010 of the present invention is used as part of the illumination lighting control system of the room 2003. The illumination lighting control system is constituted by constituent members of the whole room, for example, including the daylighting apparatus 2010, a plurality of indoor illuminating apparatuses 2007, an insolation adjusting apparatus 2008 installed on the window, a control system of these components, and the light reflective ceiling material 2003A installed on the ceiling 2003a.
The daylighting apparatus 2010 is installed on the upper part of the window 2002 of the room 2003, and the insolation adjusting apparatus 2008 is installed on the lower part of the window 2002 of the room 2003. Although a blind is installed as the insolation adjusting apparatus 2008 here, the isolation adjusting apparatus 2008 is not limited to this.
In the room 2003, the plurality of indoor illuminating apparatuses 2007 are arranged in gridlike fashion in the transverse direction (Y direction) of the window 2002 and the depth direction (X direction) of the inside of the room. The plurality of indoor illuminating apparatuses 2007 are combined with the daylighting apparatus 2010 to constitute the whole illuminating system of the room 2003.
Each of the indoor illuminating apparatuses 2007 includes an indoor illuminator 2007a, a brightness detecting section 2007b, and a control section 2007c, and the brightness detecting section 2007b and the control section 2007c are integrated with the indoor illuminator 2007a.
Each of the indoor illuminating apparatuses 2007 may include a plurality of the indoor illuminators 2007a and a plurality of the brightness detecting sections 2007b. Note, however, that the brightness detecting sections 2007b are provided one by one for each separate indoor illuminator 2007a. Each of the brightness detecting sections 2007b receives light reflected by an irradiated surface illuminated by the corresponding indoor illuminator 2007a and detects the illuminance of the irradiated surface. In this example, the illuminance of the desk top surface 2005a of the desk 2005 put in the room is detected by the brightness detecting section 200b.
The control sections 2007c provided one by one for each separate indoor illuminating apparatus 2007 are connected to each other. The mutual connection between the control sections 2007c allows each of the indoor illuminating apparatuses 2007 to perform feedback control to adjust the optical output of an LED lamp of a corresponding indoor illuminator 2007a so that the illuminance of the desk top surface 2005a as detected by the corresponding brightness detecting section 2007b becomes a given target illuminance L0 (e.g. an average illuminance of 750 lx).
As shown in
As mentioned above, combined use of the daylighting apparatus 2010 and the illumination lighting control system (indoor illuminating apparatuses 2007) allow light to reach the back of the room, thus making it possible to further increase the brightness of the inside of the room and ensure a desk top surface illuminance believed to be sufficient for work across the whole room. This provides a more stable bright light environment regardless of seasons or weathers.
The present invention is not limited in technical scope to the embodiments described above, but may be modified in various ways, provided such modifications do not depart from the spirit of the present invention.
For example, although the embodiments have been described above by taking an example of a daylighting apparatus configured such that a visible light-reflecting sheet, a daylighting sheet, and a light-diffusing sheet are bonded to glass plates, respectively, and these glass plates are housed in a frame, a daylighting apparatus is not necessarily limited to this configuration. A daylighting apparatus does not need to include a frame but may take the form of a roll screen or the like that is suspended from a ceiling by using a given supporting member.
Although the embodiments have been described above by taking an example of a configuration in which a daylighting apparatus is installed on an indoor side of a window pane, a daylighting apparatus may be housed, for example, in an internal space of double-glazed glass constituting a window pane. In addition, specific configurations related to the number, placement, shapes, dimensions, materials, and the like of each of the constituent elements constituting a daylighting apparatus can be changed as appropriate.
The preset invention is applicable to a daylighting apparatus for letting outside light such as sunlight into a room.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-217261 | Oct 2014 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/079984 | 10/23/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/063977 | 4/28/2016 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4673609 | Hill | Jun 1987 | A |
| 20140160570 | Jaster | Jun 2014 | A1 |
| 20150309228 | Vasiliev | Oct 2015 | A1 |
| 20160076718 | Gardiner | Mar 2016 | A1 |
| 20170114972 | Padiyath | Apr 2017 | A1 |
| 20170146208 | Ueki | May 2017 | A1 |
| Number | Date | Country |
|---|---|---|
| 2010-138659 | Jun 2010 | JP |
| 2011-117161 | Jun 2011 | JP |
| 2013-156554 | Aug 2013 | JP |
| 2014-163209 | Sep 2014 | JP |
| Entry |
|---|
| International Search Report for PCT/JP2015/079984, dated Dec. 15, 2015, 3 pages. |
| Written Opinion of the ISA for PCT/JP2015/079984, dated Dec. 15, 2015, 5 pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20170307160 A1 | Oct 2017 | US |
