Patent Publication Number: US-2021164630-A1

Title: Lighting device

Description:
TECHNICAL FIELD 
     The present invention relates to a lighting device. 
     The present application claims priority to JP 2018-099849 A filed in Japan on May 24, 2018, and JP 2018-167117 A filed in Japan on Sep. 6, 2018, of which contents are incorporated herein by reference. 
     BACKGROUND ART 
     Lighting devices for drawing sunlight into rooms through windows of buildings and the like are conventionally known. For example, PTL 1 described below proposes a lighting device including a lighting film in which a film base portion in which a plurality of fine structures are provided on one surface, a protective layer covering the plurality of fine structures, and a plate-like member provided on the other surface of the film base material are laminated via an adhesive layer. PTL 2 describes a hanging wall member containing a flexible sheet in an outer frame. 
     CITATION LIST 
     Patent Literature 
     PTL 1: JP 2013-156554 A 
     PTL 2: JP 2016-129582 A 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the configuration described in PTL 1, since the coefficients of linear expansion of the members constituting the lighting film are different, in a case where members of different materials are bonded together, warping or deflection of the lighting film due to changes in the surrounding thermal environment occur due to differences in the respective ratios of expansion and contraction, and the appearance thereof is affected. PTL 2 proposes a configuration that prevents the occurrence of wrinkling of a flexible sheet by fitting the flexible sheet into an outer frame. However, because a portion of the flexible sheet is fixed to the outer frame, deflection of the flexible sheet is difficult to prevent, and overall deformation tends to occur. Therefore, this configuration cannot be applied to a lighting device. 
     One aspect of the present invention has been made in view of the problems of the known technology described above, and an object of the present invention is to provide a lighting device capable of preventing warping, deflection, and deformation of a lighting film due to changes in the surrounding thermal environment. 
     Solution to Problem 
     A lighting device of one aspect of the present invention includes: a lighting film having a rectangular shape including a first surface and a second surface; and a support member configured to support the lighting film on at least two opposite sides of four sides of the lighting film so that the first surface and the second surface are positioned substantially parallel to a vertical direction, wherein the support member includes: a first support portion disposed opposite the first surface; a second support portion disposed opposite the second surface; an own weight support portion supporting an own weight of the lighting film; and a stretch allowance portion configured to allow elongation or shrinkage in a direction parallel to the first surface and the second surface of the lighting film due to a change in temperature. 
     A lighting device of one aspect of the present invention may have a configuration in which the support member includes an upper side member provided along an upper side of the lighting film and a lower side member provided along a lower side of the lighting film, the upper side member includes an upper groove into which an upper side of the lighting film is inserted, the lower side member includes a lower groove into which a lower side of the lighting film is inserted, the own weight support portion is constituted by a bottom portion of the lower groove or a bottom portion of the upper groove, and the stretch allowance portion is constituted by a gap between the upper side of the lighting film and the bottom portion of the upper groove or a gap between the lower side of the lighting film and the bottom portion of the lower groove. 
     A lighting device of one aspect of the present invention may have a configuration in which the lighting device satisfies Relationship (1) below in a case where a thickness of the lighting film is denoted by W 1 , a width of the upper groove or the lower groove is denoted by W 2 , and a depth of the upper groove or the lower groove is denoted by Lb. 
         Lb *tan 5 °+W 1*cos 5 °≥W 2 &gt;W 1   (1)
 
     A lighting device of one aspect of the present invention may have a configuration in which the support member includes an upper side member provided along an upper side of the lighting film and a lower side member provided along a lower side of the lighting film, a hole is provided in a region on a side of the upper side of the lighting film, the upper side member includes an upper side member main body and an insertion member inserted through the hole of the lighting film, and the own weight support portion is constituted by the insertion member. 
     A lighting device of one aspect of the present invention may have a configuration in which the lower side member includes a lower groove into which the lower side of the lighting film is inserted, and the stretch allowance portion is constituted by a gap between the lower side of the lighting film and a bottom portion of the lower groove. 
     A lighting device of one aspect of the present invention may have a configuration in which the lower side member includes a lower side opening portion penetrating up and down and into which the lower side of the lighting film is inserted, and the stretch allowance portion is constituted by the lower side opening portion. 
     A lighting device of one aspect of the present invention may have a configuration in which a screw hole penetrating in a horizontal direction is provided in the upper side member main body, and the insertion member is constituted by the screw hole of the upper side member main body and a screw inserted through the hole of the lighting film. 
     A lighting device of one aspect of the present invention may have a configuration in which, in the lighting film, a longitudinal dimension of an exposed portion exposed from the upper side member and the lower side member is greater than a total of a longitudinal dimension of an unexposed portion covered by the upper side member and the lower side member. 
     A lighting device of one aspect of the present invention may be configured further including: a suppressing member disposed opposite the first surface and the second surface in an exposed portion of the lighting film exposed from the support member, and the suppressing member suppressing deflection of the lighting film. 
     A lighting device of one aspect of the present invention may have a configuration in which the first support portion includes a first surface disposed opposite a window surface, the second support portion includes a second surface disposed toward an indoor side, and a distance from the first surface of the first support portion to the first surface of the lighting film is less than a distance from the second surface of the second support portion to the second surface of the lighting film. 
     A lighting device of one aspect of the present invention may be configured further including: at least one or more protective sheets supported by the support member and covering at least a portion of the first surface or at least a portion of the second surface of the lighting film. 
     A lighting device of one aspect of the present invention may be configured including: a lighting film including a first surface for light to enter and a second surface that is opposed to the first surface and that emits the light of entry, the lighting film emitting the light of entry in a predetermined direction; and a support member including a first support portion disposed opposite the first surface, a second support portion disposed opposite the second surface, and a stretch allowance portion configured to allow elongation or shrinkage of the lighting film due to a change in temperature. 
     A lighting device of one aspect of the present invention may have a configuration in which the stretch allowance portion is a gap portion between the support member and the lighting film. 
     A lighting device of one aspect of the present invention may have a configuration in which the support member supports the lighting film on at least two opposite sides of four sides of the lighting film on a rectangle so that the first surface and the second surface are arranged in a vertical direction. 
     A lighting device of one aspect of the present invention may have a configuration in which the support member includes a groove configured to house an end portion of the lighting film. 
     A lighting device of one aspect of the present invention may have a configuration in which a movement suppressing portion configured to suppress movement of the lighting film is provided between the support member and the lighting film. 
     A lighting device of one aspect of the present invention may have a configuration in which the movement suppressing portion is a protrusion portion in contact with the lighting film provided on the support member. 
     A lighting device of one aspect of the present invention may have a configuration in which the movement suppressing portion is constituted by a material having a Young&#39;s modulus lower than that of the support member. 
     A lighting device of one aspect of the present invention may have a configuration in which the movement suppressing portion is constituted by a same material as the support member. 
     A lighting device of one aspect of the present invention may have a configuration in which the movement suppressing portion is a bent portion provided in the lighting film by bending a portion of an end portion of the lighting film. 
     A lighting device of one aspect of the present invention may have a configuration in which a ridge portion formed linearly along an end portion of the lighting film is provided on the protrusion portion. 
     A lighting device of one aspect of the present invention may have a configuration in which one or more protruding portions are provided on the protrusion portion. 
     A lighting device of one aspect of the present invention may have a configuration in which the movement suppressing portion has a concave-convex shape formed on a surface. 
     Advantage Effects of Invention 
     According to the present invention, a lighting device capable of preventing warping, deflection, and deformation of a lighting film due to changes in the surrounding thermal environment can be provided. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view illustrating the appearance of a lighting device  1  installed in a window, viewed from the indoor side (arrow A side illustrated in  FIG. 2 ). 
         FIG. 2  is a cross-sectional view taken along line A-A′ of  FIG. 1 . 
         FIG. 3  is a perspective view illustrating a configuration of a lighting film  12 . 
         FIG. 4  is a cross-sectional view illustrating a shape of a lighting portion  3 . 
         FIG. 5  is a cross-sectional view illustrating a configuration of a lighting unit  10 . 
         FIG. 6  is a diagram for explaining the positional relationship between a support member  13  and the lighting film  12 . 
         FIG. 7  is a diagram for explaining a width dimension of a groove. 
         FIG. 8  is a diagram for explaining a shape of the support member  13 . 
         FIG. 9A  is a perspective view illustrating a configuration of a support member having three-sided support. 
         FIG. 9B  is a perspective view illustrating a configuration of a support member having four-sided support. 
         FIG. 10  is a perspective view of a lighting unit  20  according to a second embodiment. 
         FIG. 11  is a cross-sectional view taken along line B-B′ of  FIG. 10 . 
         FIG. 12  is a perspective view of a lighting film  24 . 
         FIG. 13  is a perspective view of a lighting unit  30  according to a third embodiment. 
         FIG. 14  is a cross-sectional view taken along line C-C′ of  FIG. 13 . 
         FIG. 15  is a perspective view of a lighting unit  40  according to a fourth embodiment. 
         FIG. 16  is a cross-sectional view taken along line D-D′ of  FIG. 15 . 
         FIG. 17  is a perspective view of a lighting unit  50  according to a fifth embodiment. 
         FIG. 18  is a cross-sectional view taken along line E-E′ of  FIG. 17 . 
         FIG. 19  is a perspective view of a lighting unit  60  according to a sixth embodiment. 
         FIG. 20  is a cross-sectional view taken along line F-F′ of  FIG. 19 . 
         FIG. 21  is a perspective view of a lighting unit  70  according to a seventh embodiment. 
         FIG. 22  is a cross-sectional view taken along line G-G′ of  FIG. 21 . 
         FIG. 23A  is a perspective view illustrating a configuration in which pressing members are provided so as to extend in a horizontal direction. 
         FIG. 23B  is a perspective view illustrating a configuration in which pressing members are provided so as to intersect in the horizontal direction and the vertical direction. 
         FIG. 24  is a cross-sectional view of a lighting unit  80  according to an eighth embodiment. 
         FIG. 25  is a cross-sectional view illustrating a modified example of a support axis structure. 
         FIG. 26  is a schematic view illustrating a configuration of a lighting device  200  installed in a window. 
         FIG. 27  is a schematic view illustrating a configuration of a lighting unit  210 . 
         FIG. 28  is a schematic view illustrating a configuration of the lighting unit  210 . 
         FIG. 29  is a schematic view illustrating a main portion of the lighting unit  210  according to a ninth embodiment. 
         FIG. 30  is a cross-sectional view taken along line XXX-XXX of  FIG. 29 . 
         FIG. 31  is a cross-sectional view of a lighting unit  215  of a tenth embodiment. 
         FIG. 32  is an enlarged view of a protrusion portion  216 . 
         FIG. 33  is a cross-sectional view of a lighting unit  220  of an eleventh embodiment. 
         FIG. 34  is a schematic view illustrating a main portion of a lighting unit  225  of a twelfth embodiment. 
         FIG. 35  is a cross-sectional view of a lighting unit  230  according to another embodiment. 
         FIG. 36  is a cross-sectional view of a lighting unit  235  according to another embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
     Hereinafter, a lighting device  1  according to a first embodiment of the present invention will be described. 
     Note that, in each of the drawings below, the scale of the dimensions may be illustrated differently depending on the constituent elements in order to facilitate viewing of the components. 
       FIG. 1  is a front view illustrating the appearance of a lighting device  1  installed in a window, viewed from the indoor side (arrow R side illustrated in  FIG. 2 ).  FIG. 2  is a cross-sectional view taken along line A-A′ of  FIG. 1 .  FIG. 3  is a perspective view illustrating a configuration of a lighting film  12 .  FIG. 4  is a cross-sectional view illustrating a shape of a lighting portion  3 .  FIG. 5  is a cross-sectional view illustrating a configuration of a lighting unit  10 .  FIG. 6  is a diagram for explaining the positional relationship between a support member  13  and the lighting film  12 .  FIG. 7  is a diagram for explaining a width dimension of a groove.  FIG. 8  is a diagram for explaining a shape of the support member  13 . 
     As illustrated in  FIGS. 1 and 2 , the lighting device  1  includes a lighting unit  10  including a lighting film  12  and a support member  13 , and a pair of mounting portions  11 . The reference sign  8  illustrated in  FIG. 1  denotes a window glass, the reference sign  108  denotes a window sash, and the reference sign  109  denotes a window frame. 
     Lighting Film 
     As illustrated in  FIGS. 3 and 5 , the lighting film  12  is a rectangular film having a light incident surface (first surface)  12 A and a light emission surface (second surface)  12 B. The lighting film  12  includes a base portion  2  having light transmittance, a plurality of lighting portions  3  provided on a first surface  2   a  of the base portion  2 , and gap portions  4  provided between the plurality of lighting portions  3 . The plurality of lighting portions  3  reflect and refract incident external light and direct the light into the room. Note that the light incident surface  12 A of the lighting film  12  is different from the light incident surface of each of the lighting portions  3 , and as illustrated in  FIG. 5 , the light incident surface  12 A is defined as the same virtual plane as the first surface  2   a  of the base portion  2 , which will be described later. 
     Note that in the present embodiment, the plurality of lighting portions  3  are formed integrally with the base portion  2  with the same material as the base portion  2 . Therefore, the interface between the plurality of lighting portions  3  and the base portion  2  is not actually present, but for convenience of explanation, in the drawing of  FIG. 3 , the first surface  2   a  of the base portion  2  is illustrated as a virtual plane (dot-dash line) that forms the same plane as the first surface  3 A ( FIG. 4 ) of the lighting portion  3  described below. 
     The base portion  2  and the lighting portions  3  are formed from an ultraviolet (UV) curing resin or a thermosetting resin. Specific examples of the UV curing resin include urethane acrylate, acrylic resin acrylate, epoxy acrylate, and the like. Examples of the thermosetting resin include amino resins, urea resins, polyurethanes, epoxy resins, unsaturated polyester resins, and the like. 
     A resin material obtained by mixing a polymerization initiator, a coupling agent, a monomer, an organic solvent, or the like can be used as the resin material described above. Furthermore, the polymerization initiator may include various additives such as stabilizers, inhibitors, plasticizers, optical brighteners, release agents, chain transfer agents, other photopolymerizable monomers. 
     As illustrated in  FIG. 3 , each of the plurality of lighting portions  3  extends in the longitudinal direction of the base portion  2 , and is disposed side by side in the lateral direction of the base portion  2 . As illustrated in  FIG. 4 , the lighting portion  3  is constituted in a prism structure having a polygonal cross-sectional shape perpendicular to the longitudinal direction. The lighting portion  3  has six top portions q1 to q6 in a cross-sectional shape perpendicular to the longitudinal direction, for example, and is a hexagonal shape with an internal angle of each of the top portions q1 to q6 being less than 180°. Of the surfaces  3 A to  3 F of the lighting portion  3 , the fourth surface  3 D, the fifth surface  3 E, and the sixth surface  3 F located below the virtual plane F perpendicular to the first surface  3 A that passes through the top portion q3 function as reflection surfaces that reflect light incident from the second surface  3 B or the third surface  3 C. 
     Air is present in the gap portions  4  (space) between adjacent lighting portions  3 . Therefore, the interface between the lighting portion  3  and the gap portion  4  is the interface between the resin and the air. The gap portions  4  may be filled with other low refractive index materials. However, the difference in refractive index at the interface between the interior and the exterior of the lighting portion  3  is maximum in a case where air is present than a case where any low refractive index material is present in the exterior. 
     Support Member 
     As illustrated in  FIGS. 1 and 5 , the support member  13  supports the lighting film  12  in at least two opposing sides (in the present embodiment, the upper side  12   a  and the lower side  12   b , see  FIG. 5 ) among four sides of the lighting film  12 , so that the light incident surface  12 A and the light emission surface  12 B are positioned substantially parallel with the vertical direction. As illustrated in  FIG. 5 , the support member  13  includes at least an upper side member  13 A provided along the upper side  12   a  of the lighting film  12  and a lower side member  13 B provided along the lower side  12   b  of the lighting film  12 . The upper side member  13 A and the lower side member  13 B have the same configuration as each other, for example, made of aluminum, but different configurations may be used. 
     The upper side member  13 A has an upper groove  14  into which an upper side  12   a  of the lighting film  12  is inserted. The upper groove  14  is formed by a first support portion  13   a  disposed opposite the light incident surface  12 A of the lighting film  12 , a second support portion  13   b  disposed opposite the light emission surface  12 B, and an upper side connecting portion  13   c  that connects the first support portion  13   a  and the second support portion  13   b  in the upper side member  13 A. 
     The lower side member  13 B has a lower groove  15  into which the lower side  12   b  of the lighting film  12  is inserted. The lower groove  15  is formed by a first support portion  13   a , a second support portion  13   b , and a lower side connecting portion  13   d  that connects the first support portion  13   a  and the second support portion  13   b  in the lower side member  13 B. The lower side connecting portion  13   d  of the lower side member  13 B is the bottom portion of the lower groove  15 , and functions as an own weight support portion  16  that supports the own weight of the lighting film  12  inserted into the lower groove  15 . 
     As illustrated in  FIG. 1 , the support member  13  further includes a pair of coupling members  17  and  17  that connect the upper side member  13 A and the lower side member  13 B. The pair of coupling members  17  and  17  are members that fix the upper side member  13 A and the lower side member  13 B to keep in a parallel state with each other along the upper side  12   a  ( FIG. 5 ) and the lower side  12   b  ( FIG. 5 ) of the lighting film  12 , and extend perpendicular to the upper side member  13 A and the lower side member  13 B. One of the coupling members  17  connects one end sides of the upper side member  13 A and the lower side member  13 B, and the other coupling member  17  connects the other end sides of the upper side member  13 A and the lower side member  13 B. 
     In the present embodiment, as illustrated in  FIG. 5 , the upper side member  13 A and the lower side member  13 B are connected at a slightly larger interval than the vertical dimension of the lighting film  12 . The coupling members  17  and  17  are desirably provided at a position that does not interfere with the lighting function of the lighting film  12 , and the size, shape, and the like are not limited to those illustrated. 
     As illustrated in  FIG. 5 , the lighting film  12  inserted into the upper groove  14  and the lower groove  15  of the support member  13  is stored in a flat state and held vertically. The lighting film  12  housed in the support member  13  has the lower side  12   b  projecting against the lower side connecting portion  13   d  of the lower groove  15 , and its own weight is supported by the own weight support portion  16 , which is the bottom portion of the lower groove  15 . 
     On the other hand, as described above, the upper side member  13 A and the lower side member  13 B have an interval with a space that is more leeway than in the vertical dimension of the lighting film  12 , so the upper side  12   a  side of the lighting film  12  does not project against the bottom portion of the upper groove  14 . The gap formed between the bottom portion of the upper groove  14 , that is, the upper side connecting portion  13   c  of the upper side member  13 A, and the upper side  12   a  of the lighting film  12  functions as a stretch allowance portion  18  according to an aspect of the present invention. The stretch allowance portion  18  is a portion that allows elongation or shrinkage in a direction parallel to the light incident surface  12 A and the light emission surface  12 B, along with a change in the temperature of the lighting film  12  housed within the support member  13 . 
     Next, the dimensions and positional relationships of the members will be described in detail with reference to  FIG. 6 . 
     In  FIG. 6 , with the bottom surface  15   a  of the lower groove  15  in the lower side member  13 B as the reference position L 0 , from the reference position L 0 , the distance to the lower side  12   b  of the lighting film  12  is L 1 , the distance to the opening side surface  15   b  of the lower groove  15  in the lower side member  13 B is L 2 , the distance to the opening side surface  14   b  of the upper groove  14  in the upper side member  13 A is L 3 , the distance to the upper side  12   a  of the lighting film  12  is L 4 , and the distance to the bottom surface  14   a  of the upper groove  14  in the upper side member  13 A is L 5 . 
     In the present embodiment, as illustrated in  FIG. 5 , the lower side  12   b  of the lighting film  12  projects against the bottom portion of the lower groove  15  (L 0 =L 1 ). In the upper groove  14 , there is a gap referred to as the stretch allowance portion  18  between the upper side  12   a  of the lighting film  12  and the bottom portion of the upper groove  14 , so the lighting film  12  does not contact the bottom portion of the upper groove  14  (L 4 &lt;L 5 ). Thus, the positional relationship of each member can be represented by L 0 =L 1 &lt;L 2 &lt;L 3 &lt;L 4 &lt;L 5 . 
     For the arrangement interval between the lower side member  13 B and the upper side member  13 A, the length from the bottom portion of the lower groove  15  to the bottom portion of the upper groove  14  is longer than the height dimension in the vertical direction of the lighting film  12 , for example, by about 4 mm, so as to have a degree of freedom in the vertical direction of the lighting film  12 . 
     Considering the dimensions of the stretch allowance portion  18  described above, the arrangement interval (L 2 -L 3  distance) between the upper side member  13 A and the lower side member  13 B is smaller than the height dimension (L 4 -L 1 ) in the vertical direction of the lighting film  12 , so the structure is configured to support the lighting film  12  with the support member  13 . 
     In the lighting film  12  housed in the support member  13 , it is desirable that a dimension (L 3 -L 2 ) in the vertical direction of the exposed portion  7  exposed from the upper side member  13 A and the lower side member  13 B of the support member  13  be greater than half of the vertical dimension (L 4 -L 1 ) of the lighting film  12 . It is desirable to fill L 3 -L 2 &gt;(L 4 -L 1 )/2 in a case of expressing with the reference sings in  FIG. 6 . 
     The portion of the lighting film  12  inserted into the upper groove  14  and the lower groove  15  of the support member  13  is covered by the upper side member  13 A and the lower side member  13 B, so a lighting effect cannot be obtained. Therefore, it is desirable to configure the vertical dimension of the exposed portion  7  of the lighting film  12  larger than the total depth of the upper groove  14  and the lower groove  15 , and to ensure a broad lighting region as much as possible. 
     Specifically, in a case where the dimension (L 4 -L 1 ) of the lighting film  12  in the vertical direction is 330 mm, for example, the dimension (L 3 -L 2 ) in the vertical direction of the exposed portion  7  of the lighting film  12  is preferably approximately 300 mm. 
     The depth (L 5 -L 3 ) of the upper groove  14  and the depth (L 2 ) of the lower groove  15  are each preferably from approximately 15 mm to 30 mm. 
     The width of the upper groove  14  and the lower groove  15  in the thickness direction of the lighting film  12  is slightly wider than the thickness of the lighting film  12  and is preferably from approximately 0.5 mm to approximately 3 mm with respect to the thickness of the lighting film  12 . 
     Specifically, as illustrated in  FIG. 7 , the lighting film  12  is supported in a state of being inclined with respect to the lower groove  15  in contact with the inner wall surface or corner portion of the lower groove  15  of the lower side member  13 B. Therefore, in a case where the thickness of the lighting film  12  is W 1 , the width of the lower groove  15  is W 2 , the depth of the upper groove or lower groove  15  is Lb, and the inclination angle of the lighting film  12  is 5°, it is desirable to satisfy Relationship (1) below. 
         Lb *tan 5 °+W 1*cos 5 °≥W 2 &gt;W 1   (1)
 
     Note that in a case where the lighting film  12  is in contact with the upper groove  14 , the same as described above may be considered, and W 2  of Relationship (1) may be set to the width of the upper groove  14 . 
     The upper side member  13 A and the lower side member  13 B may each have an asymmetrical shape in the thickness direction. For example, as illustrated in  FIG. 8 , the thicknesses of the first support portion  13   a  and the second support portion  13   b  of the upper side member  13 A and the lower side member  13 B of the support member  13  may be different from each other. 
     As illustrated in  FIG. 8 , the first support portion  13   a  of each of the upper side member  13 A and the lower side member  13 B has a first surface  94  disposed opposite the window surface, and the second support portion  13   b  has a second surface  95  disposed toward the indoor side. In a case where the distance from the first surface  94  of the first support portion  13   a  to the light incident surface  12 A of the lighting film  12  is D 1 , and the distance from the second surface  95  of the second support portion  13   b  to the light emission surface  12 B of the lighting film  12  is D 2 , the first support portion  13   a  may have a thickness that is less than the thickness of the second support portion  13   b  such that the distance D 1  from the first surface  94  of the first support portion  13   a  to the light incident surface  12 A of the lighting film  12  is shorter than the distance D 2  from the first surface  94  of the first support portion  13   a  to the light incident surface  12 A of the lighting film  12  (D 1 &lt;D 2 ). 
     As illustrated in  FIG. 1 , the lighting unit  10  of the present embodiment is mounted in the room in a state of being suspended from the upper portion of the window frame  109  by a pair of mounting portions  11 . Each of the mounting portions  11  includes an attachment member  21  for attaching the lighting unit  10  to the window frame  109 , and a plurality of attachment screws  22 . As illustrated, the attachment member  21  may be integrally formed with the coupling member  17  of the support member  13  described above, or may be a separate member from the coupling member  17 . 
     In this way, the lighting unit  10  is installed in the window frame  109  via the mounting portions  11 . As illustrated in  FIG. 2 , the lighting unit  10  is in a position in which the fine structural surface  3   a  of the lighting film  12  faces the window glass  8  and is parallel to the window glass  8 . 
     In the present embodiment, the configuration is to accommodate only by inserting the lighting film  12  into the upper and lower grooves  14  and  15  of the support member  13 , so it is not necessary to secure the upper side  12   a  and the lower side  12   b  of the lighting film  12  to the upper side member  13 A and the lower side member  13 B of the support member  13 , with an adhesive, adhesive tape, and the like. Therefore, in a case where thermal expansion or thermal contraction occurs in the lighting film  12  due to the thermal environment inside the room in which the lighting device  1  is installed, wrinkles or warping originating from the adhering portion with respect to the support member  13  do not occur. 
     Furthermore, in the present embodiment, the distance between the bottom portions of the upper and lower grooves  14  and  15  in the support member  13  is configured to be longer than the height dimension of the lighting film  12 . As a result, with the lighting film  12  housed in the upper and lower grooves  14  and  15  of the support member  13 , a gap is created between the upper side  12   a  of the lighting film  12  and the bottom portion (upper side connecting portion  13   c ) of the upper groove  14 , and this gap functions as a stretch allowance portion  18  that allows the lighting film  12  to expand and contract. As a result, the degree of freedom of stretching of the lighting film  12  within the support member  13  is ensured, and in a case where the lighting film  12  thermally expands or contracts, no external force is applied to the lighting film  12  from the support member  13 , so the flatness of the lighting film  12  can be maintained. In this way, appearance changes due to warping, deflection, deformation, or the like of the lighting film  12  due to changes in the surrounding thermal environment can be prevented. 
     Furthermore, in the present embodiment, the width dimensions of the upper groove  14  and the lower groove  15  of the support member  13  are sized to satisfy Relationship (1) described above, so the inclination angle of the lighting film  12  in the thickness direction can be set to within 5° in a case where the lighting film  12  is inserted into the support member  13 . In a case where the inclination angle in front and behind of the lighting film  12  is 5° or greater, the appearance of the lighting film  12  is affected, such as color cracking or glare, but by suppressing the inclination angle to within 5°, it is possible to suppress the effects on the appearance as described above. 
     As illustrated in  FIG. 8 , in a case where the thickness of the window side of the support member  13  is thinner than that of the indoor side, the lighting film  12  can be brought closer to the window, so the lighting effect can be increased. 
     Note that in the present embodiment, two upper and lower sides of the lighting film  12  are supported by the support member  13 , but no such limitation is intended. It is sufficient that at least two sides of the four sides of the lighting film  12  are supported by the support member  13 , and for example, the configurations illustrated in  FIGS. 9A and 9B  may be used. 
       FIG. 9A  illustrates a configuration in which three other sides other than the upper side  12   a  of the lighting film  12  are supported, and  FIG. 9B  illustrates a configuration in which all four sides of the lighting film  12  are supported. The support member  131  illustrated in  FIG. 9A  and the support member  132  illustrated in  FIG. 9B  each include a left side member  131   a  provided along the left side of the lighting film  12 , and a right side member  131   b  provided along the right side of the lighting film  12 , which are at least two sides facing each other. 
     Grooves (not illustrated) capable of inserting the left and right sides of the lighting film  12  are formed in the left side member  131   a  and the right side member  131   b . Here, the distance between the bottom portions of the left and right grooves is set to be longer than the lateral width of the lighting film  12 . As a result, it is possible to ensure the degree of freedom of stretching of the lighting film  12  in the left and right direction, and it is possible to prevent external forces from the support member  13  from being applied to the lighting film  12  in a case where the lighting film  12  expands or contracts. 
     Second Embodiment 
     Next, a configuration of a second embodiment of a lighting unit  20  will be described. 
     The basic configuration of the lighting unit  20  described below is substantially the same as that of the first embodiment described above, but the configuration of the support member differs from that of the first embodiment. 
       FIG. 10  is a perspective view of the lighting unit  20  according to the second embodiment.  FIG. 11  is a cross-sectional view taken along line B-B′ of  FIG. 10 .  FIG. 12  is a perspective view of a lighting film  24 . 
     As illustrated in  FIG. 10 , the lighting unit  20  of the present embodiment includes a support member  23  having at least an upper side member  23 A provided along an upper side  24   a  of the lighting film  24  and a lower side member  23 B provided along the lower side  12   b  of the lighting film  24 . As illustrated in  FIG. 12 , a hole  25  penetrating through the thickness direction is formed in a region on the upper side  24   a  side of the lighting film  24  substantially in the center in the length direction. 
     As illustrated in  FIG. 11 , the upper side member  23 A includes an upper side member main body  26  and an insertion member  27 . The upper side member main body  26  includes a first support portion  26   a  disposed opposite the light incident surface  24 A of the lighting film  24 , a second support portion  26   b  disposed opposite the light emission surface  24 B, and a pair of coupling members  26   c  and  26   c  that couple both end sides of the first support portion  26   a  and the second support portion  26   b . The upper side member main body  26  has an upper side opening portion  28  that penetrates up and down. The upper side  24   a  of the lighting film  24  is inserted into the upper side opening portion  28 . A screw hole  29  penetrating in the horizontal direction is provided in the first support portion  26   a  and the second support portion  26   b  of the upper side member main body  26 . 
     The insertion member  27  is made of a screw and is inserted through the screw hole  29  of the first support portion  26   a and the second support portion  26   b  in the upper side member main body  26 , and is inserted through the hole  25  of the lighting film  24 . The lighting film  24  is provided on the upper side member main body  26  via the insertion member  27  and is suspended from the insertion member  27 . In other words, the own weight support portion of the present embodiment is constituted by the insertion member  27 . The diameter d 1  of the hole  25  of the lighting film  24  is preferably larger than the axial diameter d 2  of the insertion member  27  (d 1 &gt;d 2 ). Note that an insertion pin may be used as the insertion member  27 . 
     The lower side member  23 B has a configuration similar to that of the first embodiment and includes a lower groove  15 . A lower side  24   b  of the lighting film  24  is inserted into the lower groove  15 . 
     In  FIG. 11 , in a case where the distance from the reference position L 0  of the lower side member  23 B to the lower surface  26   e  of the upper side member main body  26  is L 3 , the distance from the reference position L 0  to the upper surface  26   d  is L 5 ′, and L 1 , L 2 , and L 4  are similar to  FIG. 6 , by setting the positional relationship of each member to be L 0 &lt;L 1 &lt;L 2 &lt;L 3 &lt;L 4 &lt;L 5 ′, the lower side  24   b  of the lighting film  24  can be floating from the bottom portion of the lower groove  15  without hitting the bottom portion of the lower groove  15 . The gap between the lower side  24   b  of the lighting film  24  and the bottom portion of the lower groove  15  functions as a stretch allowance portion  18  that allows thermal expansion and thermal contraction of the lighting film  24 . 
     As described above, in the present embodiment, the lighting film  24  is suspended in the support member  23  by the insertion member  27 , and the lower side  24   b  is held floating from the bottom portion of the lower groove  15 . For this reason, thermal expansion or thermal contraction of the lighting film  24  is allowed by the stretch allowance portion  18  formed between the lower side  24   b  and the bottom portion of the lower groove  15 . As a result, as in the previous embodiment, the external force from the support member  23  is not applied in a case where thermal expansion or thermal contraction of the lighting film  24  occurs, so the flatness of the lighting film  24  can be maintained, and changes in the appearance due to deflection, deformation, and the like of the lighting film  24  can be prevented. 
     The diameter d 1  of the hole  25  of the lighting film  24  is formed larger than the axial diameter d 2  of the insertion member  27  (d 1 &gt;d 2 ), and the upper side opening portion  28  of the upper side member  23 A also penetrates up and down, so thermal expansion or thermal contraction of the lighting film  24  can be tolerated even in the hole  25  and the upper side opening portion  28 . 
     In the present embodiment, the lighting film  24  is configured to be coupled to the support member  23  via the insertion member  27 , so it is possible to prevent the lighting film  24  from falling out of the support member  23 . 
     In the present embodiment, by configuring the width of the upper side opening portion  28  and the lower groove  15  to satisfy Relationship (1) described above, the same effects as those of the previous embodiment can be obtained. 
     Note that there may be at least one point at which the lighting film  24  is suspended, but a plurality of points may be provided depending on the size and the like of the lighting film  24 . Because the upper side member  23 A of the support member  23  is provided with the upper side opening portion  28  that penetrates up and down, the lighting film  24  is easily held horizontally by providing two or more hanging points. 
     Third Embodiment 
     Next, a configuration of a third embodiment of a lighting unit will be described. 
     The basic configuration of a lighting unit  30  of the present embodiment described below is substantially the same as that of the second embodiment described above, but the configuration of the lower side member of the support member differs from that of the second embodiment. 
       FIG. 13  is a perspective view of the lighting unit  30  according to the third embodiment.  FIG. 14  is a cross-sectional view taken along line C-C′ of  FIG. 13 . 
     As illustrated in  FIG. 13  and  FIG. 14 , the lighting unit  30  of the present embodiment includes a support member  33  having at least an upper side member  33 A provided along the upper side  24   a  of the lighting film  24  and a lower side member  33 B provided along the lower side  24   b  of the lighting film  24 , and suspends and holds the lighting film  24 . The upper side member  33 A is the same as the configuration of the upper side member of the second embodiment. 
     The lower side member  33 B is formed by a first support portion  34   a  disposed opposite the light incident surface  24 A of the lighting film  24 , a second support portion  34   b  disposed opposite the light emission surface  24 B, and a pair of coupling members  34   c  and  34   c  that connect both end sides of the first support portion  34   a  and the second support portion  34   b . The lower side member  33 B has a lower side opening portion  39  that penetrates up and down and through which the lower side  24   b  of the lighting film  24  is inserted. Because the lower side opening portion  39  penetrates up and down, the lower side opening portion  39  functions as a stretch allowance portion  19  that allows thermal expansion and contraction of the lighting film  24 . 
     In  FIG. 14 , the lower surface  33   b  of the lower side member  33 B is set as the reference position L 0 ′, and L 1 , L 2 , L 3 , L 4 , and L 5 ′ are the same as in  FIG. 6 . In the present embodiment, the lighting film  24  in a state in which thermal contraction has not occurred is held in the support member  33  at a position where the lower side  24   b  is in L 0 ′≤L 1  with respect to the lower side member  33 B, and a position where the upper side  24   a  is in L 4 ≤L 5  with respect to the upper side member  33 A. 
     In the present embodiment, by providing the lower side opening portion  39  that penetrates up and down in the lower side member  33 B, the lower side  24   b  does not project against the lower side member  33 B regardless of the expansion ratio of the lighting film  24 . The lower side opening portion  39  functions as the stretch allowance portion  19  to ensure the degree of freedom of stretching of the lighting film  24  suspended and housed within the support member  33 . As a result, similar to the above-described embodiment, even in a case where thermal expansion or thermal contraction occurs in the lighting film  24 , no external force is applied from the support member  33 , and warping or deformation can be prevented. 
     In the present embodiment as well, by configuring the width of the upper side opening portion  38  and the lower side opening portion  39  to satisfy Relationship (1) described above, the same effects as those of the previous embodiment can be obtained. 
     In the present embodiment, since the upper and lower sides of the support member  23  are open, the mounting position of the lighting film  24  with respect to the support member  33  can be appropriately changed in the vertical direction because the upper side  24   a  and the lower side  24   b  of the lighting film  24  do not project against the support member  33  in the vertical direction. 
     Next, several embodiments will be described in which the mounting position of the lighting film  24  with respect to the support member  33  is varied. The basic configurations of the lighting unit according to the fourth to sixth embodiments illustrated below are substantially the same as that of the third embodiment, but the mounting position of the lighting film  24  with respect to the support member  33  differs from the third embodiment. 
     Fourth Embodiment 
     First, a configuration of a fourth embodiment of a lighting unit  40  will be described. 
       FIG. 15  is a perspective view of the lighting unit  40  according to the fourth embodiment.  FIG. 16  is a cross-sectional view taken along line D-D′ of  FIG. 15 . 
     As illustrated in  FIGS. 15 and 16 , in the present embodiment, the lighting film  24  is suspended and held in a state (L 5 ′&lt;L 4 ) in which the upper side  24   a  protrudes upward from the upper side member  33 A with respect to the support member  33 . The lower side  24   b  of the lighting film  24  is located above the reference position L 0 ′ or at the same position as the reference position L (L 0 ′≤L 1 ). The mounting position of the lighting film  24  with respect to the support member  33  can be adjusted by changing the position of the hole  25  of the lighting film  24 . 
     As in the present embodiment, even in a configuration in which the upper side  24   a  of the lighting film  24  is held so as to protrude upward from the upper side member  33 A, the same effects as those of the previous embodiment can be obtained. 
     Fifth Embodiment 
     Next, a configuration of a fifth embodiment of a lighting unit  50  will be described. 
       FIG. 17  is a perspective view of the lighting unit  50  according to the fifth embodiment.  FIG. 18  is a cross-sectional view taken along line E-E′ of  FIG. 17 . 
     As illustrated in  FIGS. 17 and 18 , in the present embodiment, the lighting film  24  is suspended and held in a state (L 1 &lt;L 0 ′) in which the lower side  24   b  protrudes downward from the lower side member  33 B with respect to the support member  33 . However, in the above-described relationship, as in the present embodiment, in a case where any position is below the reference position L 0 ′, then the distance L 1  is set to a negative value. The upper side  24   a  of the lighting film  24  is located below the upper surface  33   a  of the upper side member  33 A or at the same position as the reference position L (L 4 ≤L 5 ′). 
     As in the present embodiment, even in a configuration in which the lower side  24   b  of the lighting film  24  protrudes downward from the lower side member  33 B and keeps this state, the same effects as those of the previous embodiment can be obtained. 
     Sixth Embodiment 
     Next, a configuration of a sixth embodiment of a lighting unit  60  will be described. 
       FIG. 19  is a perspective view of the lighting unit  60  according to the sixth embodiment.  FIG. 20  is a cross-sectional view taken along line F-F′ of  FIG. 19 . 
     As illustrated in  FIGS. 19 and 20 , in the present embodiment, with respect to the support member  33 , the lighting film  24  is suspended and held in a state (L 1 &lt;L 0 ′, L 5 ′&lt;L 4 ) in which the upper side  24   a  and the lower side  24   b  are respectively vertically protruding from the upper surface  33   a  and the lower surface  33   b  of the support member  33 . 
     As in the present embodiment, even in a configuration in which the upper and lower sides of the lighting film  24  are respectively protruding from the upper side member  33 A or the lower side member  33 B, the same effects as those of the previous embodiment can be obtained. 
     Seventh embodiment 
     Next, a configuration of a seventh embodiment of a lighting unit  70  will be described. 
     The basic configuration of the lighting unit  70  of the present embodiment described below is substantially the same as that of the first embodiment, but the configuration of the support member differs from that of the first embodiment. 
       FIG. 21  is a perspective view of the lighting unit  70  according to the seventh embodiment.  FIG. 22  is a cross-sectional view taken along line G-G′ of  FIG. 21 .  FIG. 23A  is a perspective view illustrating a configuration in which pressing members  73 C are provided so as to extend in a horizontal direction.  FIG. 23B  is a perspective view illustrating a configuration in which pressing members  73 C are provided so as to intersect in the horizontal direction and the vertical direction. 
     As illustrated in  FIGS. 21 and 22 , the lighting unit  70  of the present embodiment includes a support member  73  having an upper side member  73 A, a lower side member  73 B, and narrow rod-shaped pressing members  73 C extending in the vertical direction between the upper side member  73 A and the lower side member  73 B. The upper side member  73 A and the lower side member  73 B are the same as the configurations of the first embodiment. 
     The pressing members  73 C are disposed facing each of the light incident surface  12 A and the light emission surface  12 B in the exposed portion of the lighting film  12  exposed from the support member  23 . Acrylic bars, for example, are used as the pressing members  73 C. The pressing members  73 C preferably have a higher rigidity than the lighting film  12  and have light transmittance. 
     In the present embodiment, six of the pressing members  73 C are provided at predetermined intervals in the horizontal direction, but the number and arrangement intervals of the pressing members  73 C are set as appropriate in accordance with the size of the lighting film  12 . The pressing member  73 C disposed on the light incident surface  12 A side of the lighting film  12  and the pressing member  73 C disposed on the light emission surface  12 B side are disposed facing each other via the lighting film  12 , but may be arranged so as to be offset from each other. The cross-sectional shape of the pressing members  73 C is not particularly limited. For example, the shape may be a circle, an ellipse, a triangle, a square, or the like. 
     According to the present embodiment, the two sides of the lighting film  12  in the thickness direction are locally sandwiched by the plurality of pressing members  73 C, and thus a structure is obtained in which deflection of the lighting film  12  is further suppressed. In particular, this is effective because overall deflection can be further suppressed, such as in a case where the lighting film  12  is increased in area. 
     The extension direction of the pressing member  73 C is not limited to a vertical direction. For example, as illustrated in  FIG. 23A , the plurality of horizontally extending pressing members  73 C may be provided at intervals in the vertical direction, or as illustrated in  FIG. 23B , the plurality of pressing members  73 C may be provided in a lattice shape so as to extend in the vertical direction and the horizontal direction, respectively. 
     Note that the pressing structure of the present embodiment can be used in other embodiments described above. 
     Eighth Embodiment 
     Next, a configuration of an eighth embodiment of a lighting unit will be described. 
     The basic configuration of the lighting unit  80  described below is substantially the same as that of the first embodiment described above, but differs from the first embodiment in that the lighting unit  80  includes protective sheets  81  of the lighting film  12 . 
       FIG. 24  is a cross-sectional view of the lighting unit  80  according to the eighth embodiment. 
     As illustrated in  FIG. 24 , the lighting unit  80  of the present embodiment is configured with a lighting film  12 , a support member  83 , and a pair of protective sheets  81  and  81 . The support member  83  is the same as the configuration of the first embodiment. 
     One protective sheet  81  is provided on the window side of the support member  83  and is bonded to the front surfaces  83   a  and  83   a  of the upper side member  83 A and the lower side member  83 B via adhesive tape (not illustrated) or the like. The other protective sheet  81  is provided on the indoor side of the support member  83 , and is bonded to the rear surfaces  83   b  and  83   b  of the upper side member  83 A and the lower side member  83 B via adhesive tape (not illustrated) or the like. 
     The protective sheets  81  are made of a highly transparent material. The protective sheets  81  have a larger area than the exposed portion of the lighting film  12  and covers the entire exposed portion. 
     As in the present embodiment, by providing the protective sheets  81 , it is possible to prevent scratches and dirt from being attached to the lighting film  12 . Flame resistance as the lighting device  1  can be increased by using a flame retardant, non-flammable protective sheet  81 . 
     Note that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present invention. 
     For example, an example of a configuration is described in which the thickness of the support member  13  is thinner on the window side than the indoor side, but the thicknesses may be the same as each other. 
     As long as the support member  13  is provided with a stretch allowance portion, a configuration is also conceivable in which the side end surface of the lighting film  12  is fixed to and supported by the support member  13 .  FIG. 25  is a cross-sectional view illustrating a modified example of the support structure. For example, as illustrated in  FIG. 25 , a method of fixing the lighting film  12  to the bottom portion of the upper groove  14  of the upper side member  13 A with an adhesive tape or the like not illustrated is described. At this time, the end surface along the upper side  12   a  of the lighting film  12  is bonded to the bottom portion of the upper groove  14  by an adhesive material not illustrated or the like, and the light incident surface  12 A and the light emission surface  12 B side of the lighting film  12  are not adhered to the support member  13 . By setting the arrangement interval between the upper side member  13 A and the lower side member  13 B such that the positional relationship of each member is in L 0 &lt;L 1 &lt;L 2 &lt;L 3 &lt;L 4 =L 5 , the lower side  12   b  side of the lighting film  12  is held in a floating state in the lower groove  15 . The gap created between the lower side  12   b  and the bottom portion of the lower groove  15  functions as a stretch allowance portion  18 . 
     In this manner, by fixing only the side end surface of the upper side  12   a  of the lighting film  12  and freeing the lower side  12   b  side with the stretch allowance portion  18 , the lighting film  12  is able to expand and contract in the planar direction of the lighting film  12 , and it is possible to alleviate the occurrence of warping and wrinkles accompanying stretching of the film in the stretch allowance portion  18 . 
     Ninth Embodiment 
     The lighting devices  1  of the first to eighth embodiments have configurations in which the lighting film  12  or  24  is supported mainly on the sides of the two ends in the vertical direction of the lighting film  12  or  24 . The present embodiment is configured to support the lighting film  12  or  24  on the sides of the two ends in the horizontal direction of the lighting film  12  or  24 . 
       FIG. 26  illustrates a configuration of a lighting device  200  according to the present embodiment. In the lighting device  200 , two sides of the ends in the horizontal direction of the lighting unit  210  are connected to the panel frame  202 A by the coupling members  204 . The panel frame  202 A is a frame for fixing a panel  202 B, which is a plate shaped glass, resin, or the like having translucency used in windows of buildings, vehicles, and the like. 
       FIGS. 27 and 28  illustrate the configuration of the lighting unit  210 . The lighting unit  210  includes a lighting film  12  or  24  that has a first surface and a second surface, and exits an incident light  1 , which is, for example, light entering the first surface from the outdoor, out of the second surface opposite to the first surface toward a predetermined direction within the room as an emission light  3 . 
     As illustrated in  FIG. 27 , the lighting unit  210  is provided with a support member  211  including a first support portion  211   a  disposed opposite the first surface, a second support portion  211   b  disposed opposite the second surface, and a groove  211   c  that houses an end portion of the lighting film  12  or  24 . 
     In a case where the groove  211   c  is not provided, the lighting film  12  or  24  is sandwiched by a movement suppressing portion  213  provided in the first support portion  211   a  and the second support portion  211   b . In a case where the groove  211   c  is not provided, the movement suppressing portion  213  described below serves as a cushioning material, and pressure greater than or equal to a predetermined value can be prevented from being applied to the lighting film  12  or  24 . 
     Because the support member  211  supports the lighting film  12  or  24  without adhering, it is possible to reduce the occurrence of wrinkles or warping originating from the adhering portion. 
     In the lighting unit  210 , as illustrated in  FIG. 28 , the support member  211  constituted by side portion support members  211 A and  211 B, an upper portion support member  211 C, and a lower portion support member  211 D supports the lighting film  12  or  24 . 
     The junctions between the side portion support member  211 A and  211 B and the upper portion support member  211 C (lower portion support member  211 D) are an oblique delimiter as illustrated in delimiter portions  205  in  FIGS. 27 and 28 . Note that the horizontal delimiters may be formed as illustrated in delimiter portions  206  in  FIG. 29 , which will be described later. 
     The side portion support member  211 A includes a first support portion  211 Aa, a second support portion  211 Ab, and a groove  211 Ac. The side portion support member  211 B includes a first support portion  211 Ba, a second support portion  211 Bb, and a groove  211 Bc. 
     Similarly, the upper portion support member  211 C includes a first support portion  211 Ca, a second support portion  211 Cb, and a groove  211 Cc. The lower portion support member  211 D includes a first support portion  211 Da, a second support portion  211 Db, and a groove  211 Dc. 
     As illustrated in  FIGS. 27 and 28 , the first support portion  211   a  includes the first support portions  211 Aa,  211 Ba,  211 Ca, and  211 Da, and the second support portion  211   b  includes the second support portions  211 Ab,  211 Bb,  211 Cb,  211 Db. 
     Note that in  FIG. 26 , the lighting unit  210  is provided with the upper portion support member  211 C and the lower portion support member  211 D, but as indicated by the dotted lines in  FIGS. 27 and 28 , the upper portion support member  211 C and the lower portion support member  211 D are not necessarily required. 
     In the case where the upper portion support member  211 C and the lower portion support member  211 D are not present, the lighting film  12  or  24  is supported by the side portion support member  211 A and  211 B. Conversely, the upper portion support member  211 C and the lower portion support member  211 D may support the lighting film  12  or  24 , and in this case, the side portion support members  211 A and  211 B are not necessary. 
     In a case where the side portion support members  211 A and  211 B and the upper portion support member  211 C and the lower portion support member  211 D are used in combination, the upper portion support member  211 C and the lower portion support member  211 D may use the same support members  13 ,  23 ,  33 , and  73  as the above-described first to eighth embodiments. 
       FIG. 29  is a schematic view illustrating a main portion of the lighting unit  210  according to the present embodiment. A movement suppressing portion  213  is provided on the side portion support member  211 A for suppressing movement of the lighting film  12  or  24  due to elongation or contraction caused by changes in the thermal environment and the like. 
     Note that the side portion support member  211 B has the same configuration as the side portion support member  211 A, and thus descriptions thereof will be omitted. 
     The movement suppressing portion  213  is made of a material having a lower Young&#39;s modulus than the side portion support member  211 A in order to suppress movement of the lighting film  12  or  24 , and is, for example, rubber, silicon, urethane, sponge, or the like. The movement suppressing portion  213  is preferably an elastic body such as rubber from the perspective of not only absorbing and suppressing movement of the lighting film  12  or  24 , but also suppressing movement by elasticity. 
     The movement suppressing portion  213  is made of a material having a Young&#39;s modulus that is lower than that of the side portion support member  211 A, and follows the stretching of the lighting film  12  or  24  in a case of being in contact with the lighting film  12  or  24 . As a result, it is possible to reduce the occurrence of wrinkles or warping in the lighting film  12  or  24 . 
     The movement suppressing portion  213  is constituted by a first movement suppressing portion  213   a  and a second movement suppressing portion  213   b . the first movement suppressing portion  213   a  is provided on the first support portion  213 Aa, and the second movement suppressing portion  213   b  is provided on the second support  213 Ab. 
     The first movement suppressing portion  213   a  is provided on the entire surface between the lighting film  12  or  24  and the first support portion  211 Aa, and uniformly contacts the lighting film  12  or  24  over the entire surface. Similarly, the second movement suppressing portion  213   b  is provided on the entire surface between the lighting film  12  or  24  and the second support portion  211 Ab, and uniformly contacts the lighting film  12  or  24  over the entire surface. 
     The movement suppressing portion  213  is provided on the entire surface of both surfaces of the surfaces of the side portion support member  211 A facing the lighting film  12  or  24 , and can uniformly follow the stretching of the lighting film  12  or  24  by uniformly contacting the lighting film  12  or  24  over the entire surface. 
     Note that in a case where the support member  13 ,  23 ,  33 , or  73  is used in conjunction with the side portion support members  211 A and  211 B, the movement suppressing portion  213  may be provided on the support member  13 ,  23 ,  33 , or  73 . 
     In the present embodiment, the movement suppressing portion  213  is preferably provided on the side portion support member  211 A, but this is not necessary. 
     As illustrated in the cross-sectional view taken along XXX-XXX of  FIG. 29  in  FIG. 30 , the side portion support member  211 A is provided with a stretch allowance portion  214  that allows elongation or shrinkage associated with changes in the thermal environment of the lighting film  12  or  24  and the like. 
     The stretch allowance portion  214  is a gap portion between the lighting film  12  or  24  and the side portion support member  211 A, and the expansion and contraction of the lighting film  12  or  24  is allowed, so it is possible to prevent external force from being applied to the lighting film  12  or  24  in a case where the lighting film  12  or  24  stretches. 
     In a case where the thickness of the lighting film  12  or  24  is W 21 , the thickness of the first movement suppressing portion  213   a  is W 3   a   2 , the thickness of the second movement suppressing portion  213   b  is W 3   b   2 , the width of the groove  211 Ac is W 22 , and the depth of the groove  211 Ac is Lb 2 , it is desirable for the lighting unit  210  to satisfy Relationship (2) below. 
         Lb 2*tan 5 °+W 21*cos 5 °≥W 22−( W 21 +W 3 a 2 +W 3 b 2)≥0   (2)
 
     In a case where Relationship (2) is satisfied, the lighting unit  210  can suppress deflection and also suppress a phenomenon that affects the appearance of the lighting film  12  or  24 , such as color cracking or glare. 
     As described above, the lighting unit  210  according to the present embodiment is provided with the stretch allowance portion  214 , and therefore allows elongation or shrinkage associated with changes in the thermal environment of the lighting film  12  or  24  and the like. Furthermore, in a case where the movement suppressing portion  213  is provided, the lighting film  12  or  24  is prevented from moving due to elongation or contraction caused by changes in the thermal environment and the like. 
     Note that in the present embodiment, the lighting film  12  or  24  is supported by the side portion support members  211 A and  211 B. The present invention is not limited thereto, and the upper portion support member  211 C and the lower portion support member  211 D may have the same configuration as the side portion support member  211 A, and the lighting film  12  or  24  may be supported by the upper portion support member  211 C and the lower portion support member  211 D. In a case of supporting the lighting film  12  or  24  by the upper portion support member  211 C and the lower portion support member  211 D, the effects are the same as the case of supporting the lighting film  12  or  24  by the side portion support members  211 A and  211 B. 
     The lighting device  200  of the present embodiment is assumed to be applied to  202 B provided vertically in the vertical direction as in  FIG. 29 , but may also be applied to a panel provided horizontally in the horizontal direction, such as a roof window. 
     Tenth Embodiment 
     In the ninth embodiment, in the case where the movement suppressing portion  213  is provided, the movement suppressing portion  213  is provided on the entire surface of both sides of the surfaces of the side portion support member  211 A facing the lighting film  12  or  24  and is uniformly in contact with the lighting film  12  or  24  on the entire surface of the movement suppressing portion  213 . According to the present embodiment, the movement suppressing portion  213  is not limited to the case where the movement suppressing portion  213  is uniformly in contact with the entire surface, but the movement suppressing portion  213  and the lighting film  12  or  24  may come into contact with each other by a protrusion portion provided on the movement suppressing portion  213 . 
       FIG. 31  illustrates a cross-sectional view of a lighting unit  215  according to the present embodiment. As illustrated in  FIG. 31 , protrusion portions  216  are provided on both sides of the lighting film  12  or  24  in the movement suppressing portion  213  of the present embodiment. The protrusion portion  216  is provided to reduce the contact area in a case where the movement suppressing portion  213  comes into contact with the lighting film  12  or  24 . 
     In order to reduce the contact area between the movement suppressing portion  213  and the lighting film  12  or  24  by the protrusion portion  216 , the movement suppressing portion  213  can follow the stretching of the lighting film  12  or  24  even in a case where the expansion and contraction of the lighting film  12  or  24  is large compared with the ninth embodiment. 
     As illustrated in  FIG. 32 , the protrusion portion  216  may be a ridge portion that is in contact with the lighting film  12  or  24  in line and may be provided so as to extend in the vertical direction. The ridge portion may be a triangular prism, such as a protrusion portion  216   a , or a half cylinder like a protrusion portion  216   d , for example. 
     As illustrated in the enlarged view of the protrusion portion  216  in  FIG. 32 , the protrusion portion  216  may be provided as protruding portions that are in contact with the lighting film  12  or  24  at points and are arranged in a vertical direction. The protruding portions may be pyramids such as quadrangular pyramids and cones, such as the protrusion portion  216   b  and  216   c , or half spheres such as  216   e.    
     As described above, the shape of the protrusion portion  216  has a shape in which the area on the upper surface of the lighting film  12  or  24  side is narrower than the bottom surface on the side portion support member  211 A side, and damage to the protrusion portion  216  is less likely to occur while reducing the contact area with the lighting film  12  or  24 . 
     Note that the lighting unit  215  preferably also satisfies Relationship (2) described above. Note that in Relationship (2), the thickness including in the protrusion portion  216  of the first movement suppressing portion  213   a  is W 3   a   2 , and the thickness including in the protrusion portion  216  of the second movement suppressing portion  213   b  is W 3   b   2 . In the present embodiment as well, in a case where Relationship (2) is satisfied, the lighting unit  215  can suppress deflection and also suppress the phenomenon of affecting the appearance of the lighting film  12  or  24  such as color cracking or glare. 
     As described above, in a case of contacting the lighting film  12  or  24 , the protrusion portion  216  reduces the contact area between the movement suppressing portion  213  and the lighting film  12  or  24  as compared to the ninth embodiment, and it is possible to absorb the stretchable portion by a location not in contact in a case where the lighting film  12  or  24  expands and contracts. Therefore, in addition to the effects of the ninth embodiment, the lighting unit  215  according to the present embodiment can follow the stretching of the lighting film  12  or  24  even in a case where the expansion and contraction of the lighting film  12  or  24  is greater than that of the ninth embodiment. 
     Eleventh Embodiment 
     In the ninth and tenth embodiments, the case has been described in which the movement suppressing portion  213  is provided by using a material separate from the side portion support member  211 A in the side portion support member  211 A. According to the present embodiment, the embodiment is not limited to the case where the movement suppressing portion  213  is provided in the side portion support member  211 A by using a material separate from the side portion support member  211 A, and a portion of the lighting film  12  or  24  may be bent to achieve the same effect as the movement suppressing portion  213 . 
       FIG. 33  illustrates a cross-sectional view of the lighting unit  220  of the present embodiment. As illustrated in  FIG. 33 , the lighting film  12  or  24  of the present embodiment is provided with a bent portion  221  by performing a bending process on one location of the lighting film  12  or  24 . 
     From the perspective of the used material at the site where movement is suppressed, it is possible to make the lighting film  12  or  24  less likely to have wrinkles or warping generated due to elongating or shrinking of the lighting film  12  or  24  as a result of the change in the thermal environment or the like, as compared to the ninth and tenth embodiments. Because the bent portion  221  is a portion of the lighting film  12  or  24 , wrinkles or warping can be less likely to occur compared to the ninth and tenth embodiments from the perspective of the used material at the site where movement is suppressed. Note that the side where movement is suppressed is the bent portion  221  in the present embodiment, and is the movement suppressing portion  213  in the ninth and tenth embodiments. 
     The lighting unit  220  desirably satisfies Relationship (3) below in a case where the thickness of the lighting film  12  or  24  is W 21 , the bending thickness of the bent portion is W 3   c   2 , the width of the groove  211 Ac is W 22 , and the depth of the groove  211 Ac is Lb 2 . 
         Lb 2*tan 5 °+W 21*cos 5 °≥W 22−( W 21 +W 3 c 2)≥0   (3)
 
     In a case where Relationship (3) is satisfied, the lighting unit  220  can suppress deflection and also suppress a phenomenon that affects the appearance of the lighting film  12  or  24 , such as color cracking or glare. 
     As described above, in addition to the effects of the ninth embodiment, the lighting unit  220  according to the present embodiment uses the same used material at the site where movement is suppressed as the lighting film  12  or  24 , so it is possible to make wrinkles and warping of the lighting film  12  or  24  less likely to occur than the ninth and tenth embodiments. 
     Twelfth Embodiment 
     In the ninth and tenth embodiments, in the case where the movement suppressing portion  213  is provided, the movement suppressing portion  213  is provided on the entire surface of both sides of the surfaces of the side portion support member  211 A facing the lighting film  12  or  24 , and is uniformly in contact with the lighting film  12  or  24  on the entire surface of the movement suppressing portion  213 . 
     According to the present embodiment, the movement suppressing portion  213  is not limited to being provided on the entire surface of both sides of the surfaces of the side portion support member  211 A facing the lighting film  12  or  24 , and as described later, a movement suppressing portion  226  may be provided on a portion of both sides of the surfaces of the side portion support member  211 A facing the lighting film  12  or  24 . 
       FIG. 34  is a schematic view illustrating a main portion of a lighting unit  225  according to the present embodiment. As illustrated in  FIG. 34 , in the lighting unit  225  of the present embodiment, a movement suppressing portion  226  is provided on a portion of both sides of surfaces of the side portion support member  211 A facing the lighting film  12  or  24 . The movement suppressing portion  226  is constituted by a movement suppressing portion  226   a  provided on the first support portion  211 Aa and a movement suppressing portion  226   b  provided on the second support portion  211 Ab. 
     As described above, the movement suppressing portion  226  is provided on a portion of both sides of surfaces of the side portion support member  211 A facing the lighting film  12  or  24 , and it is possible to absorb the stretching portion in a case where the lighting film  12  or  24  is stretched in a location where the movement suppressing portion  226  is not provided. Therefore, in addition to the effects of the ninth embodiment, the lighting unit  225  according to the present embodiment can follow the stretching of the lighting film  12  or  24  even in a case where the expansion and contraction of the lighting film  12  or  24  is greater than that of the ninth embodiment. 
     Other Embodiments 
     In the ninth embodiment, the stretch allowance portion  214  is a gap portion, but the same effects as those of the ninth embodiment can be obtained even in a case where the movement suppressing portion  231  is portion of a stretch allowance portion  214 , as illustrated in the cross-sectional view of a lighting unit  230  in  FIG. 35 . Note that in a case where the movement suppressing portion  231  is a portion of the stretch allowance portion  214 , the lighting unit  230  desirably satisfies Relationship (2) above. 
     Since the movement suppressing portion  231  has a lower Young&#39;s modulus than the side portion support member  211 A, the lighting film  12  or  24  is pressed into the movement suppressing portion  231  that is portion of the stretch allowance portion  214  in a case where the lighting film  12  or  24  expands due to a thermal environment or the like. Because the lighting film  12  or  24  is pressed into the movement suppressing portion  231  that is portion of the stretch allowance portion  214 , it is possible to make it difficult to generate deflection of the lighting film  12  or  24 . 
     In the ninth embodiment, the movement suppressing portion  213  is provided on both sides of the lighting film  12  or  24 , but the same effects as those of the ninth embodiment can be obtained even in a case where the movement suppressing portion  232  is provided on one side as illustrated in  FIG. 35 . Note that in a case where the movement suppressing portion  232  is provided on one side, the lighting unit  230  desirably satisfies Relationship (3) above. 
     In the tenth embodiment, the movement suppressing portion  213  and the protrusion portion  216  are provided on both sides of the lighting film  12  or  24 , but the same effects as those of the tenth embodiment can be obtained even in a case where the movement suppressing portion  233  and the protrusion portion  234  are provided on one side as illustrated in  FIG. 35 . Note that in a case where the movement suppressing portion  233  and the protrusion portion  234  are provided on one side, the lighting unit  230  desirably satisfies Relationship (3) above. 
     In the eleventh embodiment, bending processing is performed at one location, but bending may be performed at two locations as illustrated in the bent portions  236  and  237  in the cross-sectional view of the lighting unit  235  in  FIG. 36 , or bending may be performed at four locations as illustrated by the bent portion  238 . The same effects as those of the eleventh embodiment can also be obtained in a case where bending is performed at two or more locations. In a case where the bent portion  236  or  237  is provided, the lighting unit  235  desirably satisfies Relationship (3), and in a case where the bent portion  238  is provided, the lighting unit  235  desirably satisfies Relationship (2). 
     In the tenth embodiment, the movement suppressing portion  213  is a different material than the side portion support member  211 A, but the same effects as those of the tenth embodiment can also be obtained with the same material as the side portion support member  211 A. 
     The same effects as those of the eleventh embodiment can be obtained even in a case where the bent portion  221  is provided only in portion of the end portion by providing notches in the accommodating end portion in the side portion support member  211 A of the lighting film  12  or  24  in the eleventh embodiment. 
     Furthermore, in the embodiment described above, an example of a panel-type lighting device  1  or  200  is described, but, for example, a lighting device  1  such as a blind, a roll-screen type, or the like may be used. 
     In addition, the specific descriptions of the shapes, numbers, arrangements, materials, and the like of the components of the lighting member and the lighting device  1  or  200  can be changed as appropriate without limitation to the above-described embodiments. 
     INDUSTRIAL APPLICABILITY 
     The present invention can be utilized in lighting devices for incorporating external light, such as sunlight, into a room.