Lighting apparatus

Abstract

To obtain a lighting apparatus which can secure the design performance of a scatter plate, and can suppress a moire phenomenon.SOLUTION: A lighting apparatus comprises: an apparatus main body having an opening at one face; a light source arranged in the apparatus main body; a plate-shaped scatter plate having a light emitting face being a light emission face of light from the light source and a rear face opposing the light emitting face, and arranged in the apparatus main body so that the light emitting face is oriented outward from the opening of the apparatus main body; and a plate-shaped protection cover arranged while being separated from the light emitting face in a direction vertical to the light emitting face of the scatter plate, and covering the light emitting face. In the protection cover, an opposing face of the scatter plate is an emboss-finished face having a plurality of protrusions.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a lighting fixture, and more particularly to a lighting fixture having a scattering plate. [Background technology]

[0002] Conventionally, there is a lighting fixture that is installed on a mounting portion such as a ceiling. The lighting fixture includes a box-shaped fixture body that is open at the bottom, a rectangular scattering plate disposed inside the fixture body, and a light source constituted by LEDs or the like that is disposed to face two opposing end faces of the scattering plate. The lighting fixture causes light emitted from the light source to be incident on the end faces of the scattering plate, and the light is emitted from the exit surface of the scattering plate that faces the opening side of the fixture body. The exit surface of the scattering plate serves as a light-emitting surface and emits light from the opening of the fixture body (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-26796 Summary of the Invention [Problem to be solved by the invention]

[0004] In the lighting fixture disclosed in Patent Document 1, the light-emitting surface of the scattering plate is exposed. Therefore, the lighting fixture disclosed in Patent Document 1 has a problem in that external foreign matter such as dust or water causes diffuse reflection on the light-emitting surface of the scattering plate, degrading the design.

[0005] Furthermore, in lighting fixtures, there is a demand for a configuration in which the moire phenomenon does not occur on the light-emitting surface of the scattering plate, as this would reduce the design appeal.

[0006] The present disclosure is intended to solve such problems, and aims to provide a lighting device that can ensure the design of the scattering plate while suppressing the moire phenomenon. [Means for solving the problem]

[0007] The lighting device of the present disclosure comprises a device body having an opening on one side, a light source arranged within the device body, a plate-shaped scattering plate having a light-emitting surface which is the emission surface of light from the light source and a back surface opposite the light-emitting surface, the plate-shaped scattering plate being arranged within the device body so that the light-emitting surface faces outward from the opening of the device body, and a plate-shaped protective cover which is arranged at a distance from the light-emitting surface in a direction perpendicular to the light-emitting surface of the scattering plate and covers the light-emitting surface, and the surface of the protective cover facing the scattering plate is an embossed surface having a plurality of protrusions. Effect of the Invention

[0008] The lighting fixture according to the present disclosure has a protective cover that covers the light-emitting surface of the scattering plate, and therefore can suppress diffuse reflection caused by external foreign matter adhering to the light-emitting surface of the scattering plate, thereby ensuring design. In addition, the lighting fixture has a surface of the protective cover facing the scattering plate that is textured with multiple protrusions, so that the contact area when the scattering plate bends and contacts the protective cover can be made smaller than when the facing surface is a flat surface without protrusions, and the moire phenomenon spreading from the contact area can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] 1 is an exploded perspective view showing a schematic overall configuration of a lighting fixture according to a first embodiment. [Diagram 2] 1 is a perspective view showing a configuration of a lighting fixture according to a first embodiment. [Diagram 3] 4 is an exploded perspective view of a lower portion of a light source unit including a part of a light source section according to the first embodiment. FIG. [Figure 4] 4 is an exploded perspective view of an upper portion of a light source unit including a power source and the remaining portion of a light source section according to the first embodiment. FIG. [Diagram 5] 3 is a cross-sectional view of a portion including a scattering plate and a protective cover of the light source unit according to the first embodiment. FIG. [Figure 6] 1 is a diagram showing a comparison result of the design of the lighting fixture 1 according to the first embodiment and the design of a conventional lighting fixture. [Figure 7] FIG. 1 is a diagram illustrating an example of the moire phenomenon. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the lighting fixture 1 according to the present disclosure will be described with reference to the drawings. In each drawing, the same reference numerals are used to denote the same or equivalent parts, and this is common throughout the entire specification. In addition, throughout the entire specification, the direction from the floor to the ceiling, i.e., the Z1 direction of the Z direction, may be referred to as the "upper direction" and the ceiling side may be referred to as the "upper side". Similarly, the perpendicular direction from the ceiling to the floor, i.e., the Z2 direction, may be referred to as the "downward direction" and the floor side may be referred to as the "lower side". The X and Y directions are perpendicular to the Z direction. In addition, in the following description, the expressions "inside" and "outside" (including inside, outside, inner surface, and outer surface) may be used to describe positional relationships and directions, but unless otherwise specified, the central part side of the lighting fixture 1 is referred to as the inside, and the outer side of the lighting fixture 1 is referred to as the outside. In addition, in each drawing, the relative dimensional relationship or shape of each component may differ from the actual one.

[0011] Embodiment 1 Fig. 1 is an exploded perspective view showing an outline of the overall configuration of a lighting fixture 1 according to embodiment 1. Fig. 2 is a perspective view showing the configuration of the lighting fixture 1 according to embodiment 1. The lighting fixture 1 emits light and has a fixture body 30 and a light source unit 100 having a light source section 10. The lighting fixture 1 is a ceiling-embedded lighting fixture. The lighting fixture 1 is formed in a quadrangle when viewed in the Z direction (hereinafter referred to as a plan view).

[0012] The fixture body 30 is formed in a rectangular box shape with an opening at the bottom. Inside the fixture body 30, a light source unit 100 having a rectangular shape in a plan view is arranged. The light source unit 100 is attached to the fixture body 30 by a V-spring 19 fixed to a decorative frame 11 (described later) of the light source section 10. The V-springs 19 are fixed to the upper surfaces of a pair of longitudinal parts extending in the longitudinal direction of the flange part 11a of the decorative frame 11 formed in a rectangular frame shape, two by two. The lighting fixture 1 is configured to be attached to the fixture body 30 by attaching the V-spring 19 of the light source unit 100 to a V-spring mounting bracket (not shown) fixed to the fixture body 30.

[0013] The lighting fixture 1 is installed so as to be embedded in an embedding hole H provided in a ceiling C. A hanging bolt B is suspended from the embedding hole H in the ceiling C. The lighting fixture 1 is embedded in the embedding hole H with the fixture body 30 suspended from the hanging bolt B. The lighting fixture 1 is installed on the ceiling such that a portion of the lighting fixture 1 except for the flange portion 11a is embedded in the embedding hole H and a lower end surface A of the flange portion 11a is exposed along the ceiling surface.

[0014] Although the outline of the structure for mounting the lighting fixture 1 to the ceiling has been described above, the mounting structure is not limited to the above and can be changed as appropriate.

[0015] Fig. 3 is an exploded perspective view of a lower portion of light source unit 100 including a part of light source section 10 according to embodiment 1. Fig. 4 is an exploded perspective view of an upper portion of light source unit 100 including the remaining portion of light source section 10 according to embodiment 1 and power supply section 20. Fig. 5 is a cross-sectional view of a portion including scattering plate 17 and protective cover 13 of light source unit 100 according to embodiment 1. The configuration of light source unit 100 of lighting fixture 1 will be described in detail below with reference to Figs. 3 to 5.

[0016] The light source unit 100 includes a light source section 10 and a power supply section 20 disposed above the light source section 10. The light source section 10 includes a decorative frame 11, a diffusion cover 12, a protective cover 13, a first light source module 14, a light source module holding member 15, a second light source module 16, a scattering plate 17, and an elastic member 18.

[0017] (Decorative Frame 11) The decorative frame 11 is configured in a frame shape penetrating in the Z direction. The decorative frame 11 has a plate shape extending in the XY plane direction, a flange portion 11a formed in a rectangular frame shape in a plan view, and a rectangular plate-like holding portion 11b extending in the Z1 direction and the X direction from the Z1 side surface of the flange portion 11a. The holding portion 11b is provided on each of two sides of the flange portion 11a facing in the Y direction. The above-mentioned V spring 19 is further fixed to the two sides of the flange portion 11a facing in the Y direction, but is omitted in FIG. 3. The decorative frame 11 is configured to have the flange portion 11a and the holding portion 11b by bending, for example, a metal plate material as shown in FIG. 5. The decorative frame 11 is not limited to being made of metal.

[0018] (Diffusion Cover 12) The diffusion cover 12 is formed in a rectangular frame shape in a plan view. The diffusion cover 12 is installed on the flange portion 11a of the decorative frame 11. The diffusion cover 12 is made of, for example, a white resin such as milky white. The diffusion cover 12 is formed in a quadrangular pyramid shape with the upper and lower sides open. Therefore, each of the four side surfaces of the diffusion cover 12 is inclined at a preset angle with respect to the vertical direction. Each of the four side surfaces of the diffusion cover 12 is made of a trapezoidal diffusion plate 12a, and the length of the upper side is shorter than the length of the lower side. In addition, since each of the four side surfaces of the diffusion cover 12 is inclined, the position of the upper side is arranged to be more inward than the position of the lower side when viewed from the Z direction. As a result, the internal space of the diffusion cover 12 is tapered and enlarged downward. As described above, the diffusion cover 12 is formed by combining four trapezoidal diffusion plates 12a. However, the method of formation is not limited to this, and the diffusion cover 12 may be formed by integral molding.

[0019] Of the four diffusion plates 12a constituting the diffusion cover 12, three of the diffusion plates 12a have light-emitting surfaces 12a1, and the remaining diffusion plate 12a has a non-light-emitting surface 12a2. The three light-emitting surfaces 12a1 are arranged in a U-shape to match the U-shaped first light source module 14 described below. The three light-emitting surfaces 12a1 are surfaces that emit white light emitted from the first light source module 14.

[0020] A light-shielding sheet (not shown) is attached to the outer surface of the diffusion plate 12a having the non-light-emitting surface 12a2, so that light does not leak from the non-light-emitting surface 12a2.

[0021] In this way, the diffusion cover 12 has a configuration in which three light-emitting surfaces 12a1 that emit white light emitted from the first light source module 14 are combined with one non-light-emitting surface 12a2 that does not emit light. Therefore, the light emitted from the diffusion cover 12 comes from three directions, so that it is possible to produce a visual effect with a sense of depth as if light from outside is shining through a window frame in the sun or through a window frame in the shade.

[0022] 3, a fixing portion 12b extending outward is provided on the upper end surface of the diffusion cover 12. The fixing portion 12b is a portion to which the protective cover 13 is fixed, and is formed in a rectangular ring shape in a plan view.

[0023] (Protective cover 13) The protective cover 13 is a transparent and light-transmitting cover formed in a plate shape, and is formed of a transparent resin material such as acrylic. The protective cover 13 is rectangular in a plan view. The protective cover 13 is adhered and fixed to the fixing portion 12b of the diffusion cover 12 with an adhesive. The protective cover 13 is not limited to a structure in which it is fixed to the fixing portion 12b, and may be formed by integral molding with the diffusion cover 12. The protective cover 13 is disposed so as to cover the upper opening of the diffusion cover 12, and closes the lower opening of the fixture body 30 together with the diffusion cover 12.

[0024] The protective cover 13 is disposed facing a light-emitting surface 17a (described later) which is the lower surface of the scattering plate 17 as shown in FIG. 5. The protective cover 13 is disposed away from the light-emitting surface 17a in a direction perpendicular to the light-emitting surface 17a of the scattering plate 17 (Z direction). The protective cover 13 transmits light emitted from the lower light-emitting surface 17a1 of the scattering plate 17. The protective cover 13 is a cover for preventing adhesion of external foreign matter to the scattering plate 17 and the occurrence of scratches on the surface due to external forces. Examples of external foreign matter include dust or water, and sebum attached during installation.

[0025] The protective cover 13 has a textured surface 50 on the surface 13a facing the scattering plate 17. The textured surface 50 has a plurality of minute protrusions 51 as shown in FIG. 5. The protrusions 51 are minute, so they are not shown in FIG. 3. The width w of the surface 13a facing the protrusions 51 is 5 μm to 10 μm. In the illustrated example, the textured surface 50 has a configuration having a plurality of protrusions 51 with the same cross-sectional shape, but is not limited to this configuration. The textured surface 50 may have a plurality of protrusions 51 with different cross-sectional shapes. In addition, the textured surface 50 may have a configuration in which the plurality of protrusions 51 are regularly arranged as in the illustrated example, or may have an irregular arrangement.

[0026] (First light source module 14) The first light source module 14 is formed in a U-shape in plan view. That is, the first light source module 14 is configured to form three of the four sides of a rectangle. The first light source module 14 has three plate-shaped substrates 14a and light sources 14b formed of white LEDs provided on each of the three substrates 14a, with the angle between adjacent substrates being 90°. In this way, the first light source module 14 is an optical module having light sources 14b.

[0027] The first light source module 14 emits white light as a first light from the light sources 14b provided on each of the three substrates 14a toward the inside of the U-shape. In this way, the first light source module 14 emits white light from the three directions constituting the U-shape. The first light source module 14 is fixed to a first holding portion 15a of a light source module holding member 15 described below as shown in FIG. 5, and is disposed outside the diffusion cover 12, and emits white light toward the diffusion cover 12.

[0028] The lighting device 1 can be used as a lighting device in which the white light of the first light source module 14 is emitted from the light-emitting surface 12a1 of the diffusion cover 12 and illuminates the diagonally downward direction of the light-emitting surface 12a1. The blue light emitted from the light-emitting surface 17a of the scattering plate 17 described later is lighting for producing a visual effect of looking at a blue sky, and the luminous flux is insufficient when used for lighting. On the other hand, the light emitted from the light-emitting surface 12a1 meets the luminous flux required for lighting. Thus, the light intensity of the white light emitted from the light-emitting surface 12a1 is different from the light intensity of the blue light emitted from the light-emitting surface 17a of the scattering plate 17, and the light intensity of the white light is stronger than the light intensity of the blue light.

[0029] The white light emitted from the light-emitting surface 12a1 does not have to be white light of a single color temperature. That is, specifically, the first light source module 14 may be provided with two types of white LEDs with different color temperatures. In this way, the first light source module 14 may be provided with only one type of white LED as the white LED, or may be provided with two types of white LEDs, a white LED for daylight and a white LED for warm color. When the first light source module 14 is provided with two types of white LEDs, white light of various color temperatures and various luminous fluxes can be emitted from the light-emitting surface 12a1 by changing the dimming rate of the two types of white LEDs.

[0030] Also, the daylight white LED and the warm white LED may be switched according to the time. Specifically, for example, the daylight white LED may be used during the daytime period from 8:00 AM to 5:00 PM, and the warm white LED may be used during the other period. The second light source module 16 may also adjust the color tone according to the time. Note that these time periods are merely examples and are not limited to these, and may be set as appropriate.

[0031] The light distribution of the white LED used in the first light source module 14 is a wide-angle type. By using a wide-angle type LED in the first light source module 14, the luminous intensity of the light emitted from the diffusion cover 12 can be made less likely to change even if the inclination angle of the light-emitting surface 12a1 of the diffusion cover 12 is changed. Therefore, the same type of white LED module can be used for diffusion covers 12 with different inclination angles.

[0032] In this embodiment, the first light source module 14 has the light source 14b configured with a white LED, but the color of the light emitted from the light source 14b is not limited and may be changed as appropriate depending on the application of the lighting fixture 1. Furthermore, the light source 14b is not limited to an LED, and other light emitting elements or light emitting devices may be used.

[0033] (Light source module holding member 15) The light source module holding member 15 is formed in a rectangular frame shape in a plan view. The light source module holding member 15 is a portion that holds the first light source module 14 and the second light source module 16. The light source module holding member 15 is formed to extend in the Z direction and has a rectangular frame-shaped first holding part 15a that holds the first light source module 14, and a rectangular frame-shaped second holding part 15b that is formed to extend inward from the Z1 side end of the first holding part 15a and holds the second light source module 16.

[0034] The first holding portion 15a has a pair of long side surface portions 15a1 formed to extend in the Z direction and the X direction and facing in the Y direction, and a pair of short side surface portions 15a2 formed to extend in the Z direction and the Y direction and facing in the X direction. As shown in FIG. 5, the first light source module 14 is fixed to the inside of a U-shaped portion formed by the pair of long side surface portions 15a1 and one of the pair of short side surface portions 15a2 of the first holding portion 15a.

[0035] The second holding portion 15b is formed by extending inward from the end portion on the Z1 side of the first holding portion 15a, and its tip portion forms a lower guide plate 15b2. The lower guide plate 15b2 is rectangular and annular in plan view. As shown in FIG. 5, a convex portion protruding in the Z2 direction is formed on the surface of the lower guide plate 15b2 facing the Z1 direction, and the end face (upper surface) of the convex portion serves as a support surface 15b2a on which the scattering plate 17 is placed. The convex portion is formed in a rectangular and annular shape in plan view, and supports the outer periphery of the four sides of the scattering plate 17 from below.

[0036] The second holder 15b has a pair of longitudinal portions that face each other in the Y direction and extend in the X direction, and has a pair of fixing portions 15b1 to which the second light source module 16 is fixed. The pair of fixing portions 15b1 are configured in the shape of rectangular plates extending in the X direction and the Z direction, and the second light source module 16 is fixed to the inner surface side of the pair of fixing portions 15b1.

[0037] (Second light source module 16) The second light source module 16 is configured in a plate shape with the X direction as the longitudinal direction, and two second light source modules 16 are provided facing each other in the Y direction. The second light source module 16 has a long plate-shaped substrate 16a with the X direction as the longitudinal direction, and a plurality of light sources 16b configured with blue LEDs provided on the substrate 16a. In this manner, the second light source module 16 is an optical module having the light source 16b. The second light source module 16 emits blue light as the second light. The second light source module 16 emits blue light from the light source 16b toward a scattering plate 17 described later. Note that, although the second light source module 16 has the light source 16b configured with a blue LED here, the color of the light emitted from the light source 16b is appropriately changed depending on the application of the lighting device 1, and the color of the light source 16b is not limited. The light source 16b is not limited to an LED, and other light emitting elements or light emitting devices may be used.

[0038] 5, the second light source module 16 is fixed to a pair of fixing portions 15b1 of the second holding portion 15b of the light source module holding member 15. The second light source module 16 is fixed to the second holding portion 15b by clamping the upper end portions of the substrate 16a and the fixing portion 15b1 of the second holding portion 15b with a clip-shaped fixing member 41.

[0039] (Scatter board 17) The scattering plate 17 is made of a transparent resin material such as acrylic and formed into a plate shape. As shown in Fig. 4, the scattering plate 17 is formed into a rectangular shape in a plan view. The scattering plate 17 has a light-emitting surface 17a, which is a lower surface and serves as an emission surface of light from the light source 16b, a back surface 17b, which is an upper surface and faces the light-emitting surface 17a, two end surfaces 17c extending in the longitudinal direction and facing each other, and two end surfaces 17d extending in the lateral direction and facing each other.

[0040] The scattering plate 17 is configured such that the outer periphery of each of the four sides is supported by the support surface 15b2a of the lower guide plate 15b2 to determine the position in the vertical direction (Z direction), and light emitted from the light source 16b of the second light source module 16 is incident on the end surface 17c. The scattering plate 17 is supported by the support surface 15b2a with a gap S between it and the protective cover 13.

[0041] The scattering plate 17 transmits the light emitted from the second light source module 16 and emits blue light from the light emitting surface 17a which serves as the emission surface. The scattering plate 17 includes scatterers therein, which are particles that scatter light. The scatterers include, for example, silica.

[0042] The back surface 17b of the scattering plate 17 is smooth in order to cause total reflection. The back surface 17b of the scattering plate 17 is preferably mirror-finished. If the back surface 17b of the scattering plate 17 is scratched during the assembly of the lighting fixture 1, total reflection is less likely to occur at the scratched area. Therefore, a part of the lower surface corresponding to the scratched area of ​​the back surface 17b may appear whitish, which may prevent the appearance of a blue sky. Therefore, in order to prevent the back surface 17b of the scattering plate 17 from being scratched, the upper surface of the scattering plate 17 may be covered with a reflective sheet.

[0043] Here, when covering the back surface 17b of the scattering plate 17 with a reflective sheet, if the reflective sheet is attached without leaving a gap between the back surface 17b of the scattering plate 17 and the reflective sheet, total reflection is unlikely to occur on the back surface 17b of the scattering plate 17. In order to ensure that light is totally reflected on the back surface 17b of the scattering plate 17, an air layer is required between the scattering plate 17 and the reflective sheet. In order to form the air layer, the reflective surface of the reflective sheet facing the back surface 17b of the scattering plate 17 is matte-finished. The matte-finishing is a process for forming fine irregularities like frosted glass. By matte-finishing the reflective surface of the reflective sheet, an air layer can be provided between the scattering plate 17 and the reflective sheet. In addition, an adhesive portion may be provided on the edge of the reflective sheet in order to fix the reflective sheet to the scattering plate 17.

[0044] (Elastic member 18) The elastic member 18 is a frame-shaped packing and is disposed between the rear surface 17b of the scattering plate 17 and a rear cover 23 described later. The elastic member 18 functions as a cushioning material when the lighting device 1 is shaken by an earthquake or the like.

[0045] (Power supply section 20) The power supply section 20 has a power supply unit 21, a control unit 22, and a rear cover 23. The power supply unit 21 supplies power to each of the first light source module 14 and the second light source module 16 to cause the light source 14b and the light source 16b to emit light. The control unit 22 is a device that controls the light emission of the first light source module 14 and the second light source module 16. The power supply unit 21 and the control unit 22 are housed in a power supply housing section 23a of the rear cover 23, and are fixed to the inside of the fixture body 30 together with the rear cover 23.

[0046] However, conventional lighting fixtures are not provided with a protective cover, and the light-emitting surface of the scattering plate is exposed. Therefore, in conventional lighting fixtures, the light-emitting surface of the scattering plate is subject to diffuse reflection due to the adhesion of foreign matter, etc., which reduces the design quality.

[0047] In response to this, the lighting fixture 1 is provided with a protective cover 13 that covers the light-emitting surface 17a of the scattering plate 17. This allows the lighting fixture 1 to prevent external foreign matter from adhering to the light-emitting surface 17a of the scattering plate 17, improving the anti-soiling performance. As a result, the lighting fixture 1 can prevent diffuse reflection on the light-emitting surface 17a of the scattering plate 17, improving the design.

[0048] The improvement in design depending on whether or not the protective cover 13 is used is shown in FIG.

[0049] Fig. 6 is a diagram showing a comparison result of the design of the lighting fixture 1 according to the embodiment 1 and the design of a conventional lighting fixture. Fig. 6 is a diagram showing the light-emitting surface when water droplets as foreign matter are attached to the exposed surface of the lighting fixture 1. The part where the water droplets are attached is shown within a dashed-dotted circle. Fig. 6(a) shows a case where a protective cover 13 is provided, and the exposed surface is the underside of the protective cover. Fig. 6(b) shows a conventional case where a protective cover 13 is not provided, and the exposed surface is the underside of a scattering plate.

[0050] As shown in Fig. 6(b), when a foreign object adheres to the scattering plate itself, diffuse reflection occurs, significantly degrading the design of the product. In contrast, as shown in Fig. 6(a), when a foreign object adheres to protective cover 13, diffuse reflection is suppressed, improving the design of the product. Although colors cannot be expressed in Fig. 6, in Fig. 6(b), the foreign object is clearly reflected as white on the blue light-emitting surface, whereas in Fig. 6(a), the foreign object is only reflected as a slightly lighter blue on the blue light-emitting surface.

[0051] In this way, by having protective cover 13, lighting fixture 1 can prevent foreign matter from directly adhering to scattering plate 17, thereby suppressing the diffuse reflection phenomenon.

[0052] It is desirable that the gap S between the scattering plate 17 and the protective cover 13 of the lighting device 1 be as small as possible. The smaller the gap S, the more beautiful the surface emission can be achieved on the light-emitting surface 17a of the scattering plate 17 of the lighting device 1. On the other hand, the larger the gap S of the lighting device 1, the more external foreign matter adhering to the protective cover 13 becomes a light-emitting body, and the more noticeable the reflection of this light-emitting body on the scattering plate 17 via the protective cover 13 becomes.

[0053] Furthermore, if the gap S of the lighting fixture 1 is large and the protective cover 13 is located on the Z2 side of the position of the first light source module 14 in the Z direction, the white light emitted from the light source 14b of the first light source module 14 is reflected by the opposing surface 13a, which is the upper surface of the protective cover 13, and the white light is reflected on the scattering plate 17. In this way, the larger the gap S of the lighting fixture 1, the more difficult it is to achieve beautiful surface emission, and the design quality is reduced.

[0054] Therefore, in the lighting device 1, the distance of the gap S in the Z direction is set to a distance that can suppress the white light emitted from the light source 14b from being reflected through the protective cover 13. This distance is greater than 0 mm and is equal to or less than 2 mm.

[0055] In this way, by minimizing the distance in the Z direction of the gap S between the scattering plate 17 and the protective cover 13, the lighting device 1 can achieve beautiful surface emission from the light-emitting surface 17a of the scattering plate 17. However, at the same time, the following problems may arise.

[0056] In the lighting device 1, when the scattering plate 17 expands in the XY plane due to thermal expansion, moisture absorption, or the like, the scattering plate 17 may bend downward and come into contact with the protective cover 13. If the opposing surface of the protective cover is flat, a moire phenomenon such as that shown in the following Figure 7 will occur when the scattering plate comes into surface contact with the opposing surface of the protective cover.

[0057] Fig. 7 is a diagram showing an example of the moire phenomenon. The moire phenomenon shown in Fig. 7 shows the moire phenomenon that occurs when the scattering plate bends downward and comes into surface contact with the protective cover when the opposing surface of the protective cover is flat, and shows a phenomenon in which a striped pattern is generated by multiple concentric circles centered on the surface contact portion 60. Specifically, the moire phenomenon (Newton ring phenomenon) is a phenomenon in which the surface contact portion 60 becomes a dark area, and bright and dark lines spread outward from the dark area as a center.

[0058] In this way, when the surface of the protective cover facing the scattering plate is a flat surface, there is a possibility that the moire phenomenon will occur. For this reason, the surface 13a of the protective cover 13 of the lighting device 1 facing the scattering plate 17 is a textured surface 50. Since the surface 13a of the protective cover 13 facing the lighting device 1 is a textured surface 50, when the scattering plate 17 is bent downward, the protrusions 51 of the textured surface 50 come into point contact with the scattering plate 17 at the apex of the protrusions 51. Therefore, compared to the surface contact when the surface 13a of the protective cover 13 facing the lighting device 1 is a flat surface, the surface 13a of the protective cover 13 facing the lighting device 1 is a textured surface 50, so that the contact area is reduced and the moire phenomenon can be suppressed.

[0059] Here, the width w of the protrusion 51 affects the transparency of the scattering plate 17 and the occurrence of the moire phenomenon. Specifically, the smaller the width w, the higher the transparency of the scattering plate 17, and conversely, the larger the width w, the lower the transparency of the scattering plate 17. Also, the smaller the width w, the more the occurrence of the moire phenomenon can be suppressed, and conversely, the larger the width, the more the occurrence of the moire phenomenon is promoted. Therefore, taking the above influences into consideration, it is preferable that the width w is set to 5 μm to 10 μm.

[0060] As described above, the lighting fixture 1 of the first embodiment includes a fixture body 30 having an opening on one surface, and a light source 16b arranged inside the fixture body 30. The lighting fixture 1 includes a plate-shaped scattering plate 17 having a light-emitting surface 17a that is an emission surface of light from the light source 16b and a back surface 17b facing the light-emitting surface 17a, the plate-shaped scattering plate 17 arranged inside the fixture body 30 such that the light-emitting surface 17a faces outward from the opening of the fixture body 30. The lighting fixture 1 includes a plate-shaped protective cover 13 that is arranged apart from the light-emitting surface 17a in a direction perpendicular to the light-emitting surface 17a of the scattering plate 17 and covers the light-emitting surface 17a. The surface 13a of the protective cover 13 facing the scattering plate 17 is a textured surface 50 having a plurality of protrusions 51.

[0061] In this way, since the lighting fixture 1 has the protective cover 13, it is possible to suppress diffuse reflection caused by external foreign matter adhering to the light-emitting surface 17a of the scattering plate 17, and to ensure design. Also, since the opposing surface 13a of the protective cover 13 facing the scattering plate 17 in the lighting fixture 1 has the textured surface 50, the contact area when the scattering plate 17 bends and contacts the protective cover 13 can be made smaller than when the opposing surface 13a is a flat surface without the protrusions 51, and the moire phenomenon spreading from the contact area can be suppressed.

[0062] Protrusions 51 of textured surface 50 have a width of 5 μm to 10 μm in the surface direction of opposing surface 13a. This allows lighting device 1 to reduce the contact area when scattering plate 17 bends and contacts protective cover 13, thereby suppressing the moire phenomenon that spreads from the contact area.

[0063] The lighting device 1 includes a diffusion cover 12 that is disposed inside the device body 30 on the opposite side to the facing surface 13a of the protective cover 13 and is formed in a frame shape when viewed from a direction perpendicular to the light-emitting surface 17a of the scattering plate 17. The lighting device 1 includes a first light source module 14 that is disposed outside the diffusion cover 12 and emits a first light toward the diffusion cover 12, and a second light source module 16 that has a light source 16b and emits a second light from the light source 16b toward the scattering plate 17. The distance between the facing surface 13a of the protective cover 13 and the light-emitting surface 17a of the scattering plate 17 (the distance in the Z direction of the gap S) is set to a distance that suppresses the first light from being reflected on the scattering plate 17 via the protective cover 13. This distance is greater than 0 mm and equal to or less than 2 mm.

[0064] This enables the lighting device 1 to suppress the first light from being reflected on the scattering plate 17 via the protective cover 13.

[0065] Although the present disclosure has been described above based on the embodiment, the present disclosure is not limited to the configuration of the above-mentioned embodiment. For example, the lighting device 1 may be provided with a light-shielding sheet to prevent light leakage from each part. Furthermore, although the lighting device 1 has been described in the embodiment with the Z direction facing up and down, it may be installed at an angle, or may be attached to a wall surface, for example. In other words, it is to be noted that the scope of various modifications, applications, and uses that a person skilled in the art may make as necessary is also included in the gist (technical scope) of the present disclosure. [Explanation of symbols]

[0066] 1 Lighting fixture, 10 Light source part, 11 Decorative frame, 11a Flange part, 11b Holding part, 12 Diffusion cover, 12a Diffusion plate, 12a1 Light emitting surface, 12a2 Non-light emitting surface, 12b Fixing part, 13 Protective cover, 13a Opposing surface, 14 First light source module, 14a Substrate, 14b Light source, 15 Light source module holding member, 15a First holding part, 15a1 Long side part, 15a2 Short side part, 15b Second holding part, 15b1 Fixing part, 15b2 Lower guide plate, 15b2a Support surface, 16 Second light source module, 16a Substrate, 16b Light source, 17 Scattering plate, 17a Light emitting surface, 17a1 Light emitting surface, 17b Back surface, 17c End surface, 17d End surface, 18 Elastic member, 19 V spring, 20 Power supply section, 21 power supply unit, 22 control unit, 23 rear cover, 23a power supply housing section, 30 fixture body, 41 fixing member, 50 embossed surface, 51 protrusion, 60 surface contact portion, 100 light source unit, A bottom end surface, B hanging bolt, C ceiling, H embedding hole, S gap.

Claims

1. A device body having an opening on one side; A light source disposed within the fixture body; a plate-shaped scattering plate having a light-emitting surface that is an exit surface of light from the light source and a back surface opposite to the light-emitting surface, the plate-shaped scattering plate being disposed within the device body such that the light-emitting surface faces outward from the opening of the device body; a plate-shaped protective cover that is disposed apart from the light-emitting surface in a direction perpendicular to the light-emitting surface of the scattering plate and covers the light-emitting surface; The protective cover has a surface facing the scattering plate which is an embossed surface having a plurality of protrusions.

2. 2. The lighting device according to claim 1, wherein each of the plurality of protrusions on the textured surface has a width of 5 μm to 10 μm in a surface direction of the opposing surface.

3. a diffusion cover disposed inside the device body on the opposite side to the opposing surface side of the protective cover and formed in a frame shape when viewed from a direction perpendicular to the light emitting surface of the scattering plate; a first light source module disposed outside the diffusion cover and configured to emit a first light toward the diffusion cover; a second light source module having the light source and emitting a second light from the light source toward the scattering plate; A lighting device as described in claim 1 or claim 2, wherein the distance between the opposing surface of the protective cover and the light-emitting surface of the scattering plate is set to a distance that suppresses reflection of the first light onto the scattering plate through the protective cover.

4. The lighting device according to claim 3, wherein the distance is greater than 0 mm and equal to or less than 2 mm.

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