JP2014086394A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device capable of easily switching a light irradiation direction.SOLUTION: A lighting device includes: a light source part 10 emitting light in a planar state; and side surfaces 10c, 10d arranged at the light-emitting surface side of the light source part and formed on a pair of surfaces 10a, 10b and on the surroundings of the surfaces 10a, 10b. The lighting device includes: a planar light introducing part emitting light from at least one of the surfaces 10a, 10b and the side surfaces 10c, 10d; and a light reflection transmitting part disposed at the light source part 10 and the other side of the light introducing part and capable of switching between a transmission condition where light from the surface 10a of the light introducing part is transmitted, and a reflecting condition where light from the surface 10a of the light introducing part is reflected.

Description

  The present invention relates to a lighting device.

  In recent years, the importance of lighting technology has increased in residential spaces such as houses and offices. In the past, the function of lighting was focused on simply giving brightness, but recently, the importance of luxury, comfort, impact on human psychology, etc. are also becoming important, and lighting designers etc. It has become an active age.

  From such a viewpoint, the light emission direction in the illumination is important. In general, direct lighting and indirect lighting are used to express lighting functions with different emission directions, and the atmosphere in the room changes greatly depending on the light emission direction, which is Also has a big impact. In recent years, in particular, housing manufacturers have been actively working on indirect lighting.

  From the above viewpoint, if there is an illuminating device that can change the emission direction with a single illuminating device, the light in the room can be controlled with a single switch, and the atmosphere in the room can be changed.

  Patent Document 1 discloses a planar illuminating device including a planar light source having translucency and a dimming mirror provided on one surface of the light source that can be switched between a reflective state and a transmissive state. Has been. In this lighting fixture, when the planar light source is turned on and the dimming mirror is in a reflecting state, the light emitted from the planar light source to the dimming mirror is reflected by the dimming mirror, The light is transmitted through the light source. In addition, when the planar light source is turned on and the dimming mirror is in a transmissive state, the light emitted from the planar light source to the dimming mirror is transmitted through the dimming mirror.

  Patent Document 2 discloses dimming that includes a rare earth metal hydride such as a magnesium-nickel alloy thin film whose material is exchanged between a mirror surface (reflection) state and a transparent state by controlling an applied voltage on an illumination cover surrounding a light bulb. An illumination device provided with a mirror layer is disclosed.

  In Patent Document 3, a plate formed using a functional member having an electric dimming characteristic is attached to the front surface of the light source, and the amount of electricity applied to the functional member having the electric dimming characteristic is adjusted. An illumination device is disclosed in which the emitted light is adjusted and changed. Specifically, a method of switching between transmission and scattering of light using an encapsulated liquid crystal as a functional member having electric dimming characteristics is disclosed. In addition, a method using an electrochromic member that changes light absorption characteristics as a functional member having electric dimming characteristics is also disclosed.

  Patent Document 4 discloses a lighting device in which an electrochromic element that is variable between colored and colorless and transparent is incorporated in floor lighting.

JP 2009-266570 A JP 2005-56706 A JP-A-6-116615 JP-A-5-74211

S. Araki et al., “Electrochemical Optical-Modulation Device with Reversible Transformation Between Transparent, Mirror, and Black”, Adv. Mater. 2012, 24, OP122-OP126

  However, these illuminating devices have the following problems, and when used for illumination for switching the atmosphere of the room described above, it is not sufficient in terms of switching the light emission direction.

  In the case of the illumination device described in Patent Document 1, when the dimming mirror is in a reflective state, both the light directly irradiated from the planar light source and the light reflected by the dimming mirror are planar. The light is emitted only in the normal direction of the mold light source. On the other hand, when the dimming mirror is in a transmissive state, the light directly emitted from the planar light source is emitted in the normal direction, and the light emitted from the planar light source to the dimming mirror is The light passes through the dimming mirror and exits in the normal direction opposite to the one normal direction. As described above, in the above luminaire, light is emitted only in a direction perpendicular to the planar light source regardless of whether the dimming mirror is in a reflection state or a transmission state. It was difficult to switch to the direction.

  In the case of the illuminating device described in Patent Document 2, it is possible to change the irradiation range directly under the illuminating device by providing an illumination cover that can be changed between a reflective state and a transparent state. It was difficult to greatly change

  In the case of the illumination device described in Patent Document 3, the light emission direction can be changed to some extent, but light cannot be emitted strongly in the lateral direction of the light source. Therefore, it cannot be an illumination device that sufficiently switches the light emission direction.

  In the case of the illumination device described in Patent Document 4, an electrochromic element that is variable between colored and colorless and transparent does not have a function of changing the light traveling direction. I don't get it.

  The objective of this invention is providing the illuminating device which can switch the irradiation direction of light easily.

  The object includes a light source unit that emits light in a planar shape, a light emitting surface side of the light source unit, a pair of surfaces and side surfaces formed around the surface, and at least one of the surfaces and A light guide unit that emits light from the side surface; a light-reflecting unit disposed on the other side of the light source unit; a reflective state that reflects light from the surface of the light guide unit; and the light guide unit This is achieved by an illuminating device having a light reflection / transmission part capable of switching a transmission state of transmitting light from the surface.

  The illuminating device of the present invention is characterized in that it further includes a light reflecting portion that is disposed on the other side of the surface of the light source portion and reflects light from the light source portion.

  In the illumination device of the present invention, the light reflection / transmission part includes an electrochromic element.

  In the illuminating device of the present invention, the light reflection / transmission section can generate an intermediate state between the reflection state and the transmission state.

  In the illumination device according to the present invention, the light reflection / transmission section includes a movable mirror.

  In the illumination device of the present invention, the light reflection / transmission section includes a liquid crystal panel including a cholesteric liquid crystal.

  In the illumination device of the present invention, the light reflection / transmission part has a crystal layer including a tunable photonic crystal.

  In the illumination device of the present invention, the light source unit includes an organic EL element or an inorganic EL element.

  In the illumination device of the present invention, the light source unit includes an LED.

  In the illumination device of the present invention, the light source unit includes a fluorescent tube.

  In the illumination device of the present invention, the light source unit includes an optical duct for taking in sunlight.

  In the lighting device of the present invention, the light source unit includes a substrate on which a phosphor layer is formed or a substrate including a phosphor.

  In the illumination device of the present invention, at least one of the adjacent interfaces of the light source unit, the light reflection / transmission unit, the light guide unit, and the light reflection unit has a range in which a refractive index of an adjacent component is an upper limit or a lower limit. It has a refractive index matching layer made of a material having a refractive index.

  In the lighting device of the present invention, the light scattering portion that scatters light has at least one of a surface or a side surface direction from which the light is emitted.

  In the illumination device of the present invention, the light scattering portion includes, for example, a scattering film, a polymer-dispersed liquid crystal, or nanoparticles.

  ADVANTAGE OF THE INVENTION According to this invention, the illuminating device which can switch the irradiation direction of light easily is realizable.

It is a figure which shows schematic cross-sectional structure of the illuminating device 1 by the 1st Embodiment of this invention. It is a schematic diagram which shows an example of a structure of the electrochromic element used for the illuminating device 1 by the 1st Embodiment of this invention. It is a schematic diagram which shows the other example of a structure of the electrochromic element used for the illuminating device 1 by the 1st Embodiment of this invention. It is a figure which shows the modification of the structure of the illuminating device 1 by the 1st Embodiment of this invention. It is a figure which shows the other modification of a structure of the illuminating device 1 by the 1st Embodiment of this invention. It is a figure which shows the other modification of a structure of the illuminating device 1 by the 1st Embodiment of this invention. It is a figure which shows schematic sectional structure of the illuminating device 2 by the 2nd Embodiment of this invention. It is a figure which shows schematic sectional structure of the illuminating device 3 by the 3rd Embodiment of this invention. It is a figure which shows schematic sectional structure of the illuminating device 4 by the 4th Embodiment of this invention. It is a figure which shows the modification of the structure of the illuminating device 4 by the 4th Embodiment of this invention. It is a figure which shows schematic sectional structure of the illuminating device 5 by the 5th Embodiment of this invention. It is a figure which shows schematic sectional structure of the illuminating device 6 by the 6th Embodiment of this invention. It is a figure which shows schematic cross-sectional structure of the illuminating device 7 by the 7th Embodiment of this invention. It is a figure which shows schematic sectional structure of the illuminating device 208 by the 8th Embodiment of this invention. It is a figure which shows schematic cross-sectional structure of the illuminating device 8 by the 9th Embodiment of this invention. It is a figure which shows schematic sectional structure of the illuminating device 9 by the 10th Embodiment of this invention. It is a figure which shows schematic sectional structure of the illuminating device 210 by the 11th Embodiment of this invention. It is a figure which shows the example of the structure which light-emits the light of arbitrary colors in the illuminating device by each embodiment of this invention. It is a figure which shows the example of the installation state of the illuminating device by each embodiment of this invention. It is a figure which shows the example of the installation state of the illuminating device by each embodiment of this invention. It is a figure which shows the example of the installation state of the illuminating device by each embodiment of this invention. It is a figure which shows the example of the installation state of the illuminating device by each embodiment of this invention.

[First Embodiment]
An illumination device according to a first embodiment of the present invention will be described with reference to FIGS. In all the following drawings, the dimensions and ratios of the respective constituent elements are appropriately varied for easy understanding. FIG. 1 shows a schematic cross-sectional configuration of a lighting apparatus 1 according to the present embodiment. FIG. 1A shows the lighting device 1 when the light control element 20 described later is in a reflective state, and FIG. 1B shows the lighting device 1 when the light control device 20 is in a transmissive state. Yes. Here, in FIGS. 1A and 1B, the light control element 20 in the reflective state is represented by hatching, and the light control element 20 in the transmission state is illustrated in white. As shown to Fig.1 (a), (b), the illuminating device 1 has the shape of a rectangular flat plate as a whole, for example.

  The lighting device 1 includes a planar light source unit 10. The light source unit 10 of the present embodiment uses an organic EL element that can emit white light. The organic EL element has a pair of electrode layers and a light emitting layer disposed between both electrode layers. Organic EL elements include single-layer type with a light-emitting layer containing a plurality of light-emitting materials, layered type with multiple light-emitting layers of different colors, and color with a phosphor that converts part of the emitted color A conversion type or the like can be used. In this example, a transparent organic EL element using a transparent material for each layer including a pair of electrode layers is used. The light source unit 10 has a rectangular flat plate shape having relatively large areas 10a and 10b facing each other and four side surfaces formed around the surfaces 10a and 10b. The light source unit 10 can emit light from the surfaces 10a and 10b and four side surfaces. In the present embodiment, the light source unit 10 also functions as a light guide unit that guides light emitted from the light source unit 10 to the surfaces 10a, 10b, or the four side surfaces.

  On the surface 10 a side of the light source unit 10, a rectangular flat plate-shaped light control element 20 (an example of a light reflection / transmission unit) is laminated and disposed. The light control element 20 can reversibly switch between a reflection state in which light from the surface 10 a of the light source unit 10 is reflected and a transmission state in which light from the surface 10 a of the light source unit 10 is transmitted. The dimming element 20 of the present embodiment uses an electrochromic element that can be electrically switched between a reflection state and a transmission state. The light control element 20 has a reflectance of about 70% in the reflection state and a transmittance of about 70% in the transmission state with respect to the light from the light source unit 10. The surface of the light control element 20 opposite to the light source unit 10 (the lower surface in the drawing) is externally transmitted by the light from the light source unit 10 through the light control device 20 when the light control device 20 is in a transmissive state. It becomes the light emission surface (light emission surface) 20a which inject | emits to. As will be described later, the dimming element 20 transmits light from the light source unit 10 in the transmissive state and emits it from the light emitting surface 20a, and reflects light from the light source unit 10 in the light source unit 10 in the reflective state. Is guided, and the light is emitted from the side surface side of the light source unit 10.

  On the surface 10 b side of the light source unit 10, a rectangular plate-like reflecting plate 30 (an example of a light reflecting unit) is laminated and arranged. The reflection plate 30 is formed using a material having high reflectance such as aluminum (Al) or silver (Ag), and reflects light from the light source unit 10 in a specular manner. The reflector 30 has a reflectance of almost 100% with respect to the light from the light source unit 10. The reflecting plate 30, the light source unit 10, and the light control element 20 have substantially the same planar shape. Instead of the reflecting plate 30, a white plate that scatters and reflects light from the light source unit 10 may be provided. Further, in order to promote interface reflection on the surface 10b of the light source unit 10 instead of the reflection plate 30, the refractive index is smaller than the refractive index near the surface 10b of the light source unit 10 (for example, the electrode layer of the organic EL element). A layer (for example, an air layer or a vacuum layer) may be provided.

FIG. 2 is a schematic diagram illustrating an example of a configuration of an electrochromic element used for the light control element 20. As shown in FIG. 2, the electrochromic element has a transparent substrate 41 such as a glass substrate. On the transparent substrate 41, a transparent conductive film 42 such as an ITO thin film, an ion storage layer 43 such as a tungsten oxide (WO ₃ ) thin film, a solid electrolyte layer 44 such as a tantalum oxide (Ta ₂ O ₅ ) thin film, an Al thin film, etc. A buffer layer 45, a catalyst layer 46 such as a palladium (Pd) thin film, and a light control mirror layer 47 such as a magnesium-nickel (Mg—Ni) alloy thin film are laminated in this order. Each layer is formed using a magnetron sputtering method or the like. The light control mirror layer 47 is reversibly switched between a mirror state and a transparent state by applying a predetermined voltage between the transparent conductive film 42 and the light control mirror layer 47 by the power supply circuit 48.

  When a predetermined voltage (for example, +5 V) is applied to the transparent conductive film 42 and a lower voltage (for example, 0 V) is applied to the light control mirror layer 47 using the power supply circuit 48, the hydrogen ions in the ion storage layer 43 are adjusted. It moves to the optical mirror layer 47 and the Mg—Ni alloy of the light control mirror layer 47 is hydrogenated. Thereby, the light control mirror layer 47 changes from a mirror state to a transparent state. Here, since the mirror state and the transparent state are both stable in the light control mirror layer 47, when the light control mirror layer 47 changes to the transparent state, the state is maintained even when the voltage application is stopped. When the light control mirror layer 47 is in a transparent state, the light control element 20 (electrochromic element) is in a transmission state (the state shown in FIG. 1B) that transmits light.

  On the other hand, when a predetermined voltage (for example, 0 V) is applied to the transparent conductive film 42 and a higher voltage (for example, +5 V) is applied to the dimming mirror layer 47, hydrogen ions in the dimming mirror layer 47 are applied to the ion storage layer 43. The Mg—Ni alloy of the light control mirror layer 47 moves and dehydrogenates. Thereby, the light control mirror layer 47 changes from a transparent state to a mirror state. When the light control mirror layer 47 changes to the mirror state, the state is maintained even when the voltage application is stopped. When the light control mirror layer 47 is in a mirror state, the light control element 20 is in a reflection state (a state shown in FIG. 1A) that reflects light.

  In this way, by switching the light control mirror layer 47 between the mirror state and the transparent state, the light control element 20 (electrochromic element) is switched between the reflection state and the transmission state.

  Here, in the electrochromic element in the reflective state, the reflectance on the surface on the light control mirror layer 47 side is higher than the reflectance on the surface on the transparent substrate 41 side. That is, the reflectance with respect to the light incident on the electrochromic element from the light control mirror layer 47 side is higher than the reflectance with respect to the light incident on the electrochromic element from the transparent substrate 41 side. This is due to light absorption, interface reflection, and the like in the transparent substrate 41 and the layers 42 to 46. Therefore, it is desirable that the dimming element 20 using the electrochromic element is disposed with the surface on the dimming mirror layer 47 side having a high reflectance in the reflecting state facing the light source unit 10 side. Note that the transmittance of the electrochromic element in the transparent state is substantially the same for both the incident light from the light control mirror layer 47 side and the incident light from the transparent substrate 41 side.

  FIG. 3 is a schematic diagram showing a configuration of an electrodeposition type electrochromic element as another example of the electrochromic element used in the light control element 20 (see Non-Patent Document 1). 3A shows the electrochromic element in the reflective state, and FIG. 3B shows the electrochromic element in the transmissive state. As shown in FIGS. 3A and 3B, the electrodeposition type electrochromic element is formed on a pair of transparent substrates 51 and 52 facing each other and on the opposing surfaces of both transparent substrates 51 and 52, respectively. Transparent conductive films 53 and 54, and an electrolyte layer 56 disposed between the transparent conductive films 53 and 54 and sealed with a sealing material 55. The electrolyte layer 56 is in a liquid state or a gel state at normal temperature, and contains Ag ions.

  When a predetermined voltage (for example, 0 V) is applied to the transparent conductive film 54 using a power supply circuit 57 and a higher voltage (for example, +2.5 V) is applied to the transparent conductive film 53, the transparent conductive film 54 and the electrolyte layer 56 are applied. Ag precipitates at the interface with the surface to form a mirror surface layer 58 (see FIG. 3A). When a predetermined voltage (for example, +2.5 V) is applied to the transparent conductive film 54 and a lower voltage (for example, 0 V) is applied to the transparent conductive film 53, a mirror surface is formed on the interface between the transparent conductive film 53 and the electrolyte layer 56. Layers can also be formed. Due to the formation of the mirror surface layer, the electrochromic element (the light control element 20) is in a reflective state that reflects light.

On the other hand, in order to change from the mirror state (for example, see FIG. 3A) to the transparent state, a predetermined voltage (for example, +0.5 V) is applied to the transparent conductive film 54, and a lower voltage ( For example, 0V) is applied. Then, Ag precipitated at the interface between the transparent conductive film 54 and the electrolyte layer 56 is dissolved in the electrolyte layer 56, and the mirror layer 58 disappears (see FIG. 3B). Thereby, an electrochromic element (light control element 20) will be in the transmissive state which permeate | transmits light.
Note that the light control element shown in FIG. 3 also has a memory property like the light control element shown in FIG. 2, and can maintain a mirror state for a certain time.

  Here, in the reflective electrochromic element shown in FIG. 3A, the reflectance of the surface on the transparent substrate 52 side is higher than the reflectance of the surface on the transparent substrate 51 side. Therefore, it is desirable that the dimming element 20 using the electrochromic element is disposed with the surface on the transparent substrate 52 side having a high reflectance in the reflecting state facing the light source unit 10 side. In other words, when the dimming element 20 using the electrodeposition type electrochromic element is brought into a reflective state, it is desirable to form a mirror layer on the transparent conductive film interface closer to the light source unit 10.

  Returning to FIG. 1, the lighting device 1 of the present embodiment is such that the reflecting plate 30 side faces upward and the dimming element 20 side faces downward (indoor side) in the recess 110 formed on the ceiling surface 100 in the room. Installed horizontally. The recess 110 is formed in a rectangular shape that is wider than the illumination device 1. Thus, spaces 120a and 120b are formed between the side surfaces of the lighting device 1 (side surfaces 10c and 10d of the light source unit 10) and the side wall surfaces 110a and 110b of the recess 110, respectively. Although not shown, spaces are also formed between the front and back side surfaces of the illumination device 1 and the front and back side wall surfaces of the recess 110, respectively. In this example, since the depth of the recessed part 110 with respect to the ceiling surface 100 and the thickness of the whole illuminating device 1 are comparable, the light emission surface 20a of the illuminating device 1 and the ceiling surface 100 are located in the substantially same plane. .

  In the lighting device 1 in the state shown in FIG. 1A (the dimming element 20 is in a reflecting state), the light source unit 10 is sandwiched between the reflecting plate 30 and the dimming element 20 (the dimming mirror layer 47) in the reflecting state. Yes. For this reason, the light emitted from the light source unit 10 is reflected directly or by the reflection plate 30 and the dimming element 20 in the reflective state, and is guided in the light source unit 10 toward the side surfaces 10c and 10d. Since the reflectance of the reflecting plate 30 is approximately 100% and the reflectance of the light control element 20 in the reflecting state is approximately 70%, most of the light emitted from the light source unit 10 is guided to the side surfaces 10c and 10d. be able to. The light that has reached the side surfaces 10c and 10d is emitted from the side surfaces 10c and 10d in a substantially horizontal direction (a direction parallel to the planar light source unit 10 and a side surface direction) as indicated by left and right thick arrows in the figure. The walls 110a and 110b are irradiated. Thereby, indirect illumination of the room using the reflected light on the side wall surfaces 110a and 110b can be performed.

  In this example, the lighting device 1 is disposed in the concave portion of the indoor ceiling, but may be disposed in a flat indoor ceiling that does not have the concave portion. In this case, the light emitted from the side surface illuminates the upper part of the wall surface in the room, and can similarly function as indirect lighting in the room.

  On the other hand, in the illuminating device 1 in the state shown in FIG. 1B (the dimming element 20 is in a transmissive state), most of the light emitted from the light source unit 10 is reflected directly or by the reflector 30 to the dimming element 20. Incident light is transmitted through the light control device 20 in the transmissive state. Since the reflectance of the reflecting plate 30 is approximately 100% and the transmittance of the light control element 20 in the transmissive state is approximately 70%, most of the light emitted from the light source unit 10 is transmitted to the light exit surface 20a. Can do. The light that has reached the light exit surface 20a is emitted from the light exit surface 20a in a substantially vertical downward direction (a direction perpendicular to the planar light source unit 10, the front direction), as indicated by a thick down arrow in the figure, and is indoors. Irradiated. Thereby, the indoor direct illumination using the direct light from the light source part 10 can be performed.

  Further, part of the light emitted from the light source unit 10 is reflected directly or by the reflecting plate 30 and guided in the light source unit 10 toward the side surfaces 10c and 10d. The light that has reached the side surfaces 10c and 10d is emitted from the side surfaces 10c and 10d in a substantially horizontal direction and irradiated on the side wall surfaces 110a and 110b, as indicated by the left and right thick arrows in the drawing. Thereby, the light from the side surface can also be used as illumination.

  As described above, according to the present embodiment, when the dimming element 20 is in the reflecting state, the light irradiation direction by the lighting device 1 can be made substantially parallel to the planar light source unit 10. When the optical element 20 is in the transmissive state, the light irradiation direction can be set to a direction substantially perpendicular to the planar light source unit 10. For this reason, the light irradiation direction by the illuminating device 1 can be easily switched by about 90 ° by switching the light control element 20 between the reflection state and the transmission state. Therefore, it is possible to easily switch between direct illumination using direct light from the light source unit 10 and indirect illumination using reflected light on the side wall surfaces 110a and 110b.

  In this embodiment, since the electrochromic element that can be electrically switched between the reflection state and the transmission state is used as the dimming element 20, a voltage of about several volts is used without using a complicated mechanism. Direct lighting and indirect lighting can be switched by electrical switching.

  Here, each merit of direct illumination and indirect illumination will be described. The advantage of direct illumination is that sufficient brightness can be obtained by illumination light that reaches directly from the illumination device in a scene where brightness is required. The advantage of indirect lighting is that indirect lighting that illuminates the wall surface feels brighter to humans than direct lighting that illuminates the floor surface, so that it is not necessary to make the light source brighter than necessary and a power saving effect can be obtained. For example, during indirect illumination, it can be felt bright even if the brightness of the light source is reduced. Another advantage of indirect lighting is that the light emitted from the side edge of the surface light source is scattered on the wall surface, giving a sense of luxury, comfort, and mood, and lighting that matches the human psychology. It can be realized.

  FIG. 4 shows a modification of the configuration of the lighting device 1. As illustrated in FIG. 4, the illumination device 1 of the present modification includes a scattering film 60 (an example of a light scattering portion) provided on the light exit surface 20 a side of the light control element 20. The scattering film 60 has a function of scattering incident light. By providing the scattering film 60, the illumination light in which light from the light source unit 10 returns to the inside due to interface reflection at the light exit surface 20 a of the light control element 20 (interface between the light control element 20 and air) in the transmissive state. Can be suppressed. Therefore, according to the configuration of this modification, it is possible to improve the efficiency of extracting direct light emitted in the front direction in the transmission state.

  Here, instead of the scattering film 60, a liquid crystal panel including a polymer dispersed liquid crystal can be used as the light scattering portion. This liquid crystal panel has a pair of transparent substrates, a polymer layer sealed between the two transparent substrates, and a plurality of liquid crystal droplets dispersed in the polymer layer. In this liquid crystal panel, when no voltage is applied, the refractive index of the polymer layer and the refractive index of the liquid crystal droplets are different because the liquid crystal molecules in the liquid crystal droplets are directed in a random direction. For this reason, light is scattered at each interface between the polymer layer and the plurality of liquid crystal droplets.

  FIG. 5 shows another modification of the configuration of the lighting device 1. As shown in FIG. 5, the illumination device 1 of the present modification includes a refractive index matching layer 71 provided between the light source unit 10 and the light control element 20 and between the light control element 20 and the scattering film 60. , 72. The refractive index matching layers 71 and 72 are made of a material having a refractive index in a range in which the refractive index of an adjacent component is the upper limit or the lower limit. In FIG. 5, the refractive index matching layer 71 has a refractive index na of the lower part of the light source unit 10 (for example, a glass substrate of an organic EL element) and the upper part of the light control element 20 (for example, the glass substrate 52 of an electrochromic element). When the refractive index is nb, the refractive index matching layer 71 has a refractive index between na and nb (for example, (na + nb) / 2). Similarly, the refractive index matching layer 72 has a refractive index between the refractive index of the light control element 20 and the refractive index of the scattering film 60. Furthermore, the refractive index matching layers 71 and 72 also function as an adhesive layer that fixes adjacent components.

  According to the configuration of the present modification, the extraction efficiency of direct light emitted in the front direction in the transmission state can be further improved as compared with the configuration shown in FIG. Compared with a configuration in which the refractive index matching layers 71 and 72 are not used, the configuration of this example improves the light extraction efficiency by about 2 to 3 times.

  In addition, when suppressing interface reflection between the light source part 10 and the light control element 20 without using the refractive index matching layer 71, the refraction of the light source part 10 is between the light source part 10 and the light control element 20. The refractive index matching agent (matching oil) having a refractive index between the refractive index and the refractive index of the light control element 20 may be filled to form the refractive index matching layer. Furthermore, the light source unit 10 and the light control element 20 can be fixed by the refractive index matching layer 71. Similarly, when the interface reflection is suppressed between the light control element 20 and the scattering film 60 without using the refractive index matching layer 72, the light control element 20 is interposed between the light control element 20 and the scattering film 60. A refractive index matching agent having a refractive index between that of the scattering film 60 and the refractive index of the scattering film 60 may be filled to form the refractive index matching layer. Further, the light control element 20 and the scattering film 60 can be fixed by the refractive index matching layer 72.

  FIG. 6 shows a modification of the configuration of the lighting device 1. As shown in FIGS. 6A and 6B, the illumination device 1 of the present modification includes a light source in addition to the scattering film 60 provided on the light exit surface 20a side of the light control element 20 shown in FIG. The side surface 10c and the side surface 10d of the part 10 also have scattering films 61 and 62 (an example of a light scattering part). Thereby, the extraction efficiency can be improved not only for the front direction of the illumination device 1 but also for the light emitted in the side surface direction.

  At the time of indirect illumination, in particular, about 40 to 50% of the light emitted from the light source can be extracted from the side surfaces by the light scattering portions on the side surface 10c and the side surface 10d of the light source unit 10. Thereby, it is possible to greatly improve the light extraction efficiency (20 to 30%) from the side surface when the scattering portion is not installed on the side surface of the light source.

[Second Embodiment]
Next, a lighting device according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 shows a schematic cross-sectional configuration of the illumination device 2 according to the present embodiment. FIG. 7A shows the illuminating device 2 when a movable mirror 80 described later is in a reflective state, and FIG. 7B shows the illuminating device 2 when the movable mirror 80 is in a transmissive state. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 7A and 7B, the illumination device 2 according to the present embodiment is a movable mirror that can be physically moved or rotated instead of the dimming element 20 of the first embodiment. 80 (an example of a light reflection / transmission part). Moreover, in this Embodiment, the depth with respect to the ceiling surface 100 of the recessed part 110 and the thickness of the reflecting plate 30 and the light source part 10 among the illuminating devices 2 (thickness other than the movable mirror 80 among the illuminating devices 2) are comparable. It is. The movable mirror 80 has a rectangular flat plate shape and is rotatable with respect to the light source unit 10 about a rotation shaft 81 provided at one end side. The movable mirror 80 takes a first position (see FIG. 7A) that is directly below the light source unit 10 and a second position that is not directly below the light source unit 10 (see FIG. 7B). obtain. In this example, the movable mirror 80 at the first position is in surface contact with the surface 10 a of the light source unit 10. The illumination device 2 is provided with a drive mechanism (not shown) that rotates the movable mirror 80 between the first position and the second position. When the movable mirror 80 is in the first position, the light from the light source unit 10 is specularly reflected by the movable mirror 80 with a reflectance of almost 100%. On the other hand, when the movable mirror 80 is in the second position, the light from the light source unit 10 is emitted downward without being reflected by the movable mirror 80. That is, the movable mirror 80 can switch between a reflection state in which the light from the light source unit 10 is reflected and a transmission state in which the light from the light source unit 10 is transmitted by physical rotation driving.

  In the illumination device 2 in the state shown in FIG. 7A (the movable mirror 80 is in a reflective state), the light source unit 10 is sandwiched between the reflector 30 and the movable mirror 80. For this reason, the light emitted from the light source unit 10 is reflected directly or by the reflecting plate 30 and the movable mirror 80 to guide the light source unit 10 toward the side surfaces 10c and 10d. Since the reflectance of the reflecting plate 30 is approximately 100% and the reflectance of the movable mirror 80 is approximately 100%, most of the light emitted from the light source unit 10 can be guided to the side surfaces 10c and 10d. The light reaching the side surfaces 10c and 10d is emitted from the side surfaces 10c and 10d in a substantially horizontal direction (a direction parallel to the planar light source unit 10) as shown by left and right thick arrows in the figure, and the side wall surfaces 110a, 110b is irradiated. Thereby, indirect illumination of the room using the reflected light on the side wall surfaces 110a and 110b can be performed.

  On the other hand, in the illuminating device 2 in the state shown in FIG. 7B (the movable mirror 80 is in a transmissive state), most of the light emitted from the light source unit 10 is reflected directly or by the reflecting plate 30, and the surface 10a of the light source unit 10 is reflected. From outside. As a result, as indicated by a downward thick arrow in the figure, the light is emitted from the surface 10a in a substantially vertically downward direction (a direction perpendicular to the planar light source unit 10) and irradiated indoors. Thereby, the indoor direct illumination using the direct light from the light source part 10 can be performed.

  Further, part of the light emitted from the light source unit 10 is reflected by the surface 10a serving as an interface with air, and is guided through the light source unit 10 toward the side surfaces 10c and 10d. The light that has reached the side surfaces 10c and 10d is emitted from the side surfaces 10c and 10d in a substantially horizontal direction and irradiated on the side wall surfaces 110a and 110b, as indicated by the left and right thick arrows in the drawing. Thereby, in addition to the direct illumination described above, indirect illumination using reflected light on the side wall surfaces 110a and 110b can also be performed.

  As described above, according to the present embodiment, when the movable mirror 80 is disposed directly under the light source unit 10 (reflective state), the light irradiation direction of the illumination device 2 is changed to the planar light source unit 10. When the movable mirror 80 is arranged away from directly below the light source unit 10 (transmission state), the light irradiation direction is a direction substantially perpendicular to the planar light source unit 10. Can be. For this reason, the irradiation direction of the light by the illuminating device 2 can be easily switched by about 90 ° by switching the movable mirror 80 between the reflection state and the transmission state. Therefore, it is possible to easily switch between direct illumination using direct light from the light source unit 10 and indirect illumination using reflected light on the side wall surfaces 110a and 110b.

  In the present embodiment, a scattering film may be attached to the surface 10a (the interface between the light source unit 10 and air) in order to suppress reflection on the surface 10a of the light source unit 10 when direct illumination is performed. A refractive index matching layer may be provided between the light source unit 10 and the scattering film. Thus, by providing a scattering film and a refractive index matching layer, the light extraction efficiency when performing direct illumination can be dramatically improved.

  In the illuminating device 2 of the present embodiment, the movable mirror 80 is configured to be rotatable between the first position and the second position, but the movable mirror 80 is positioned first below the light source unit 10. 1 may be configured to be slidable between a position 1 and a second position not directly below the light source unit 10. That is, the illuminating device 2 may have a slide mechanism capable of sliding the movable mirror 80 between the first position and the second position.

[Third Embodiment]
Next, a lighting device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 8 shows a schematic cross-sectional configuration of the illumination device 3 according to the present embodiment. FIG. 8A shows the illumination device 3 when the light control element 20 is in a reflective state, and FIG. 8B shows the illumination device 3 when the light control element 20 is in a transmission state. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 8A and 8B, the illumination device 3 according to the present embodiment includes an edge light type planar light source including a plurality of LEDs 92 and a light guide unit 91 as the light source unit 10. ing. The light guide unit 91 is, for example, a rectangle including scattering units 93 at regular intervals, such as an air layer (see FIGS. 8A and 8B) or an edge light type backlight that illuminates a liquid crystal panel. It is formed of a flat acrylic plate (see FIG. 8C. In FIG. 8C, only the light source unit 10 is extracted) and the like, and is substantially the same plane as the reflector 30 and the light control element 20 It has a shape. The LEDs 92 are provided in a line along the side surface 10c of the light guide unit 91, for example. A white LED is used for each of the LEDs 92. In this example, one end portion of the lighting device 3 provided with the LEDs 92 is hidden by the ceiling surface 100.

  In the illuminating device 3 in the state shown in FIG. 8A (the dimming element 20 is in the reflecting state), the light guide unit 91 is sandwiched between the reflecting plate 30 and the dimming element 20 in the reflecting state. For this reason, the light emitted from the LED 92 and incident on the light guide unit 91 from the side surface 10c is reflected directly or by the reflection plate 30 and the light control element 20 in the reflective state, and the light guide unit 91 is side-surfaced. Guide the light toward Since the reflectance of the reflecting plate 30 is almost 100% and the reflectance of the light control element 20 in the reflecting state is about 70%, most of the light emitted from the LED 92 and incident on the light guide unit 91 is side-surfaced. The light can be guided up to 10d. The light that has reached the side surface 10d is emitted from the side surface 10d in a substantially horizontal direction (a direction parallel to the planar light source) and irradiated onto the side wall surface 110b, as indicated by a right-pointing thick arrow in the figure. Thereby, indirect lighting in the room using the reflected light on the side wall surface 110b can be performed.

  On the other hand, in the illuminating device 3 in the state shown in FIG. 8B (the dimming element 20 is in the transmissive state), most of the light emitted from the LED 92 and entering the light guide unit 91 is reflected directly or by the reflector 30. Then, the light enters the light control element 20 and passes through the light control element 20 in a transmissive state. The reflectance of the reflecting plate 30 is almost 100%, and the transmittance of the dimming element 20 in the transmissive state is about 70%. Therefore, most of the light emitted from the LED 92 and incident in the light guide unit 91 is emitted. It can permeate | transmit to the injection surface 20a. The light that has reached the light exit surface 20a is emitted from the light exit surface 20a in a substantially vertical downward direction (perpendicular to the planar light source) and irradiated indoors, as indicated by a thick down arrow in the figure. Thereby, the indoor direct illumination using the direct light from a planar light source can be performed.

  As described above, according to the present embodiment, the light irradiation direction by the illumination device 3 can be easily changed by switching the light control element 20 between the reflection state and the transmission state as in the first embodiment. About 90 ° can be switched. Therefore, it is possible to easily switch between direct illumination using direct light from a planar light source and indirect illumination using reflected light on the side wall surface 110b.

  In the present embodiment, the LED 92 is disposed only at one end of the light guide 91, but the LED 92 may be disposed at two or more ends of the light guide 91. In the present embodiment, the LED 92 serving as a point light source is disposed at the end of the light guide 91, but a linear light source such as a straight tube fluorescent tube is disposed at the end of the light guide 91. May be.

  In the present embodiment, similarly to the configuration shown in FIG. 5, a scattering film may be provided on the light exit surface 20 a of the light control element 20, and between the LED 92 and the light guide 91, A refractive index matching layer may be provided between the light control element 20 and between the light control element 20 and the scattering film.

[Fourth Embodiment]
Next, a lighting device according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 9 shows a schematic cross-sectional configuration of the illumination device 4 according to the present embodiment. FIG. 9A shows the illumination device 4 when the light control element 20 is in a reflective state, and FIG. 9B shows the illumination device 4 when the light control element 20 is in a transmission state. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 9A and 9B, the planar light source of this embodiment includes an LED 131 and a scattering layer 132 sandwiched between a first transparent substrate 141 and a second transparent substrate 142, and the LED 131 and the light source are scattered. An air layer 133 or an acrylic resin layer is formed between the layer 132 and the layer 132. The reflective plate 30 is provided on the surface of the first transparent substrate 141 that faces the LED 131, and the light control element 20 is disposed on the opposite side of the surface of the second transparent substrate 142 that contacts the scattering layer 132. A lighting device 4 of the form is configured. The dimming element 20 includes a third transparent substrate 143 and a fourth transparent substrate 144 that are disposed to face each other, an electrolyte layer 145 that is sealed between the transparent substrates 143 and 144, and contains Ag ions, and an electrolyte layer 145. And a pair of transparent conductive films (not shown) formed on both transparent substrates 143 and 144. As described above, the illumination device 4 shown in FIGS. 9A and 9B includes the four transparent substrates 141, 142, 143, and 144 in order from the reflecting plate 30 side.

  In the lighting device 4 in the state shown in FIG. 9A (the dimming element 20 is in a reflection state), the LED 131, the air layer 133, and the scattering layer 132 are sandwiched between the reflecting plate 30 and the dimming element 20 in the reflection state. . For this reason, the light emitted from the LED 131 and passing through the air layer 133 and entering the scattering layer 132 is reflected by the light control element 20 in the reflected state while being scattered, and the air layer 133, the first transparent substrate 141, The light is guided toward the side surfaces 10 c and 10 d through the light guide portion including the second transparent substrate 142 and the third transparent substrate 143. Since the reflectance of the reflecting plate 30 is almost 100% and the reflectance of the light control device 20 in the reflecting state is about 70%, most of the light emitted from the LED 131 can be guided to the side surfaces 10c and 10d. it can. The light that has reached the side surfaces 10c and 10d is emitted from the side surfaces 10c and 10d in a substantially horizontal direction (a direction parallel to the planar light source) and irradiated on the side wall surfaces 110a and 110b, as indicated by the left and right thick arrows in the figure. Is done. Thereby, indirect illumination of the room using the reflected light on the side wall surfaces 110a and 110b can be performed.

  On the other hand, in the illumination device 4 in the state shown in FIG. 9B (the dimming element 20 is in the transmissive state), the LED 131 emits light, passes through the air layer 133 that is a part of the light guide, and enters the scattering layer 132. Most of the emitted light is reflected directly or by the reflecting plate 30 and enters the dimming element 20 and passes through the dimming element 20 in the transmissive state. Since the reflectance of the reflecting plate 30 is almost 100% and the transmittance of the light control element 20 in the transmissive state is about 70%, most of the light emitted from the LED 131 can be transmitted to the light emitting surface 20a. . The light that has reached the light exit surface 20a is emitted from the light exit surface 20a in a substantially vertical downward direction (perpendicular to the planar light source) and irradiated indoors, as indicated by a thick down arrow in the figure. Thereby, the indoor direct illumination using the direct light from a planar light source can be performed.

  In the present embodiment, the air layer 133 is used as part of the light guide, but an acrylic resin layer or the like can also be used.

  In the present embodiment, similarly to the configuration shown in FIG. 5, a scattering film may be provided on the light exit surface 20 a of the light control element 20, or between the LED 131 and the air layer 133, the air layer 133 and the scattering layer. A refractive index matching layer may be provided between the light control element 132, the light scattering element 132, the light control element 20, and the light control element 20 and the scattering film.

  Moreover, when making the light control element 20 into a reflective state, an Ag film | membrane can be deposited on both the transparent substrate 143 side and the transparent substrate 144 side. However, if the Ag film is deposited on the transparent substrate 144 side, a light absorption loss occurs in the electrolyte layer 145, and thus it is more preferable to deposit the Ag film on the transparent substrate 143 side close to the light source.

  FIGS. 10A and 10B show modified examples of the configuration of the illumination device 4. As shown in FIG. 10A, the transparent substrate 142 and the transparent substrate 143 of the lighting device 4 may be replaced with a common transparent substrate 146. Thereby, since the thickness of a planar light source and the light control element 20 can be made thin, the illuminating device 4 can be reduced in thickness.

  Further, as shown in FIG. 10B, the scattering layer 132 and the transparent substrates 142 and 143 of the illumination device 4 may be replaced with a single transparent substrate 147 having a scattering function. The transparent substrate 147 having a scattering function can be formed, for example, by dispersing fine particles (for example, a particle size of 1.0 to 7.0 μmφ) in an acrylic resin. A transparent conductive film (not shown) is formed on the surface of the transparent substrate 147 on the electrolyte layer 145 side. Thereby, since the thickness of a planar light source and the light control element 20 can be made thin, the illuminating device 4 can be reduced in thickness. Moreover, the light extracted from the light emission surface 20a can be made more uniform.

  As described above, according to the present embodiment, the light irradiation direction by the illumination device 4 can be easily changed by switching the light control element 20 between the reflection state and the transmission state, as in the first embodiment. About 90 ° can be switched. Therefore, it is possible to easily switch between direct illumination using direct light from the planar light source and indirect illumination using reflected light on the side wall surfaces 110a and 110b.

[Fifth Embodiment]
Next, the illuminating device by the 5th Embodiment of this invention is demonstrated using FIG. FIG. 11 shows a schematic cross-sectional configuration of the illumination device 5 according to the present embodiment. FIG. 11A shows the illumination device 5 when the light control element 20 is in a reflective state, and FIG. 11B shows the illumination device 5 when the light control element 20 is in a transmission state. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 11A and 11B, the illumination device 5 according to the present embodiment has a planar light source including a compact fluorescent tube 150 as the light source unit 10. The compact fluorescent tube 150 has a structure in which an arc tube is bent in one plane or a structure in which a plurality of arc tubes arranged in parallel in one plane are connected by a bridge, and is only at one end side. An electrode 151 is provided. In this example, one end portion of the lighting device 5 including the electrode 151 is hidden by the ceiling surface 100.

  In the illumination device 5 in the state shown in FIG. 11A (the dimming element 20 is in a reflecting state), the fluorescent tube 150 is sandwiched between the reflecting plate 30 and the dimming element 20 in the reflecting state. For this reason, the light emitted from the fluorescent tube 150 is reflected directly or by the reflection plate 30 and the dimming element 20 in the reflective state, and guided in the fluorescent tube 150 toward the side surface 10d. Since the reflectance of the reflecting plate 30 is almost 100% and the reflectance of the light control element 20 in the reflecting state is about 70%, most of the light emitted from the fluorescent tube 150 can be guided to the side surface 10d. it can. The light that has reached the side surface 10d is emitted from the side surface 10d in a substantially horizontal direction (a direction parallel to the planar light source) and irradiated onto the side wall surface 110b, as indicated by a right-pointing thick arrow in the figure. Thereby, indirect lighting in the room using the reflected light on the side wall surface 110b can be performed.

  On the other hand, in the illuminating device 5 in the state shown in FIG. 11B (the dimming element 20 is in a transmissive state), most of the light emitted from the fluorescent tube 150 is reflected directly or by the reflecting plate 30 and inside the dimming element 20. Is transmitted through the light control element 20 in the transmissive state. Since the reflectance of the reflecting plate 30 is almost 100% and the transmittance of the dimming element 20 in the transmissive state is about 70%, most of the light emitted from the fluorescent tube 150 is transmitted to the light emitting surface 20a. Can do. The light that has reached the light exit surface 20a is emitted from the light exit surface 20a in a substantially vertical downward direction (perpendicular to the planar light source) and irradiated indoors, as indicated by a thick down arrow in the figure. Thereby, the direct illumination of the room using the direct light from the fluorescent tube 150 can be performed.

  As described above, according to the present embodiment, similarly to the first embodiment, the light irradiation direction of the lighting device 5 can be easily changed by switching the light control element 20 between the reflection state and the transmission state. About 90 ° can be switched. Therefore, it is possible to easily switch between direct illumination using direct light from the fluorescent tube 150 and indirect illumination using reflected light on the side wall surfaces 110a and 110b.

  In the present embodiment, similarly to the configuration shown in FIG. 5, a scattering film may be provided on the light exit surface 20 a of the light control element 20, or between the fluorescent tube 150 and the light control element 20 and the light control. A refractive index matching layer may be provided between the element 20 and the scattering film.

[Sixth Embodiment]
Next, the illuminating device by the 6th Embodiment of this invention is demonstrated using FIG. FIG. 12 shows a schematic cross-sectional configuration of the illumination device 6 according to the present embodiment. FIG. 12A shows the illuminating device 6 when the light control element 20 is in a reflective state, and FIG. 12B shows the illuminating device 6 when the light control element 20 is in a transmissive state. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 12A and 12B, the illumination device 6 according to the present embodiment includes a light emitting sheet (sheet-like light source) 160 as the light source unit 10. As the light emitting sheet 160 of this example, a commercially available inorganic EL sheet (sheet-like inorganic EL element) is used. In general, a frame-shaped cover 161 is attached to the outer peripheral portion of the light emitting sheet 160. For this reason, unlike the above-described various planar light sources, it is difficult to extract light from the side surfaces 10c and 10d of the light emitting sheet 160. In the present embodiment, in order to take out the light emitted in the horizontal direction from the side of the lighting device 6 when the light control element 20 is in the reflecting state, the light source unit 10 A prism (for example, a right-angle prism) 170 is provided as a part of the prism. The prism 170 has a function of bending the traveling direction of light emitted vertically downward from the surface 10a of the light emitting sheet 160 by 90 ° and emitting the light from the light emitting surface 170a in the horizontal direction. The light control element 20 is arrange | positioned among the surfaces 10a of the light emission sheet 160 in the part (inner periphery part) except the outer peripheral part in which the prism 170 was provided.

  In the lighting device 6 in the state shown in FIG. 12A (the light control element 20 is in a reflection state), the inner peripheral portion of the light emitting sheet 160 is sandwiched between the reflection plate 30 and the light control element 20 in the reflection state. For this reason, the light emitted from the inner peripheral portion of the light emitting sheet 160 is reflected by the reflecting plate 30 and the dimming element 20 in the reflective state, and guided in the light emitting sheet 160 toward the outer peripheral portion. A part of the light reaching the outer peripheral part by the light guide in the light emitting sheet 160 and a part of the light emitted from the outer peripheral part of the light emitting sheet 160 enter the prism 170. The light incident on the prism 170 is emitted in a substantially horizontal direction from the light exit surface 170a of the prism 170 and irradiated on the side wall surfaces 110a and 110b, as indicated by the left and right thick arrows in the drawing. Thereby, indirect illumination of the room using the reflected light on the side wall surfaces 110a and 110b can be performed.

  On the other hand, in the lighting device 6 in the state shown in FIG. 12B (the light control element 20 is in the transmission state), the light emitted from the inner peripheral portion of the light emitting sheet 160 enters the light control element 20 and is in the transmission state. It passes through the light control element 20. The light that has passed through the light control element 20 and reached the light emission surface 20a is emitted from the light emission surface 20a in a substantially vertical downward direction and irradiated indoors as indicated by a downward thick arrow in the figure. Thereby, the indoor direct illumination using the direct light from the light emitting sheet 160 can be performed.

  As described above, according to the present embodiment, the light irradiation direction by the illumination device 6 can be easily changed by switching the light control element 20 between the reflection state and the transmission state as in the first embodiment. About 90 ° can be switched. Therefore, it is possible to easily switch between direct illumination using direct light from the light emitting sheet 160 and indirect illumination using reflected light on the side wall surface 110b.

  In the present embodiment, a scattering film may be provided on the light exit surface 20 a of the light control element 20 or on the light exit surface 170 a of the prism 170, or between the light emitting sheet 160 and the light control element 20. A refractive index matching layer may be provided between the prism 170 and the prism 170, between the light control element 20 and the scattering film, and between the prism 170 and the scattering film.

[Seventh Embodiment]
Next, the illuminating device by the 7th Embodiment of this invention is demonstrated using FIG. FIG. 13 shows a schematic cross-sectional configuration of the illumination device 7 according to the present embodiment. FIG. 13A shows the illumination device 7 when the light control element 20 is in a reflective state, and FIG. 13B shows the illumination device 7 when the light control element 20 is in a transmission state. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 13A and 13B, the lighting device 7 according to the present embodiment has a light duct 180 as a light source unit 10 for taking sunlight into a room. The light duct 180 includes a daylighting unit 181 for taking in sunlight, a light guiding unit 182 for guiding (propagating) the light taken in by the daylighting unit 181 by reflection on the inner wall surface, and light guided through the light guiding unit 182. In order to emit light into the room, there is a light emitting part 183 in which the bottom of the light guide part 182 is opened. On the inner wall surface of the light guide portion 182, a reflection film formed using a high reflectance material such as Al or Ag, and a laminated film that absorbs infrared light are formed. Further, a reflective film similar to the inner wall surface is formed, for example, around the light emitting portion 183 (particularly on the light traveling direction side) in the outer wall surface of the light guide portion 182. A dimming element 20 having a size larger than that of the light emission part 183 in a plan view is disposed immediately below the light emission part 183. A predetermined gap 184 is formed between the light control element 20 and the outer wall surface of the light guide unit 182 (the light traveling direction side of the light emitting unit 183).

  In the illumination device 7 in the state shown in FIG. 13A (the dimming element 20 is in a reflection state), a part of the light emitted from the light emission unit 183 is in a reflection state as indicated by a light beam L1 in the drawing. Are reflected by the light control element 20 and the outer wall surface of the light guide 182, and guide the gap 184 toward the side of the lighting device 7. The light guided through the gap 184 is emitted from the illuminating device 7 in a substantially horizontal direction as indicated by a right-pointing thick arrow in the figure, and is irradiated on the ceiling surface or wall surface of the room 190. Thereby, the indirect illumination of the room 190 using the reflected light on the ceiling surface or the wall surface can be performed.

  On the other hand, in the illuminating device 7 in the state shown in FIG. 13B (the dimming element 20 is in the transmissive state), the light emitted from the light emitting part 183 is dimmed as shown by the light beam L2 in the drawing. 20 is transmitted through the dimming element 20 in the transmissive state. The light that has reached the light emitting surface 20a of the light control element 20 is emitted substantially vertically downward from the light emitting surface 20a and is irradiated into the room 190, as indicated by the downward thick arrow in the figure. Thereby, direct illumination of the room 190 using direct light emitted from the light duct 180 can be performed.

  As described above, according to the present embodiment, similarly to the first embodiment, the light irradiation direction by the lighting device 7 can be easily changed by switching the light control element 20 between the reflection state and the transmission state. About 90 ° can be switched. Therefore, it is possible to easily switch between direct illumination using direct light emitted from the light duct 180 and indirect illumination using reflected light on the ceiling surface or wall surface.

  Moreover, according to this Embodiment, since sunlight is utilized as a light source, it is not necessary to supply power to the light source, and energy saving of the lighting device can be realized.

[Eighth Embodiment]
Next, the illuminating device by the 8th Embodiment of this invention is demonstrated using FIG. FIG. 14 shows a schematic cross-sectional configuration of the illumination device 208 according to the present embodiment. FIG. 14A shows the illumination device 208 when the light control element 20 is in the reflective state, and FIG. 14B shows the illumination device 208 when the light control element 20 is in the transmissive state. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 14A and 14B, the illumination device 208 according to the present embodiment includes a transparent substrate (glass substrate) 230 and a phosphor layer 231 formed on the transparent substrate 230 as the light source unit 10. And an LED 232 as a phosphor excitation light source. The phosphor layer 231 on the transparent substrate 230 is formed by a spin coat method or the like. In the present embodiment, the light guide unit that guides light from the light source unit 10 in the front or side direction includes the transparent substrate 230 and the phosphor layer 231. An opening (transparent portion) 30a is partially formed in the reflecting plate 30 of this example, and the LED 232 can irradiate the phosphor layer 231 through the opening 30a.

  In the illumination device 208 in the state shown in FIG. 14A (the dimming element 20 is in a reflection state), the light from the LED 232 excites and emits fluorescent molecules in the phosphor layer 231. Most of the excitation light and emitted light are guided in the transparent substrate 230 or the phosphor layer 231 and emitted in the direction of the side surface of the substrate (indirect illumination).

  On the other hand, in the illuminating device 208 in the state shown in FIG. 14B (the dimming element 20 is in the transmission state), most of the excitation light and emitted light in the phosphor layer 231 are adjusted in the transparent substrate 230 and the transmission state. It passes through the optical element 20 and is emitted in the front direction. A part of the emitted light is guided through the transparent substrate 230 or the phosphor layer 231 and emitted in the side surface direction (direct illumination).

  FIG. 14C shows a modified example of the configuration of the lighting device 208. As illustrated in FIG. 14C, the illumination device 208 of this modification includes a phosphor dispersion substrate 233 instead of the transparent substrate 230 and the phosphor layer 231. The phosphor dispersion substrate 233 is formed, for example, by dispersing a phosphor in an acrylic resin. In the present modification, the light guide unit that guides light from the light source unit 10 in the front or side direction includes the phosphor dispersion substrate 233.

  As described above, according to the present embodiment, similarly to the first embodiment, the light irradiation direction by the lighting device 208 can be easily changed by switching the light control element 20 between the reflection state and the transmission state. About 90 ° can be switched. Therefore, direct illumination using direct light from the phosphor layer 231 or the phosphor dispersion substrate 233 and indirect illumination using reflected light on the side wall surfaces 110a and 110b can be easily switched.

  Further, according to the present embodiment, since the phosphor is present on the entire surface of the planar light source, it is possible to reduce the non-uniformity of irradiation as the light source.

[Ninth Embodiment]
Next, the illuminating device by the 9th Embodiment of this invention is demonstrated using FIG. FIG. 15 shows a schematic cross-sectional configuration of the illumination device 8 according to the present embodiment. FIG. 15A shows the illumination device 8 when a light reflection / transmission plate 200 described later is in a reflection state, and FIG. 15B shows the illumination device 8 when the light reflection / transmission plate 200 is in a transmission state. Show. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 15A and 15B, the illuminating device 8 according to the present embodiment replaces the light control element 20 of the first embodiment with a light reflection / transmission plate 200 (of the light reflection / transmission part). Example). The light reflection / transmission plate 200 has at least one liquid crystal panel provided with cholesteric liquid crystal. In this example, the light reflection / transmission plate 200 has a configuration in which three liquid crystal panels 200r, 200g, and 200b are stacked.

  Each of the liquid crystal panels 200r, 200g, and 200b has a configuration in which cholesteric liquid crystal is sealed between a pair of transparent substrates on which transparent electrodes are formed. A cholesteric liquid crystal has a layered structure in which rod-like molecules are stacked several times. In each layer, the respective molecules are arranged in a certain direction, and the layers are accumulated so that the arrangement direction of the molecules is spiral. Cholesteric liquid crystal has bistability that is stable in two states, a planar state and a focal conic state.

  In the planar state, the liquid crystal molecules form a helical structure having a helical axis in the substrate normal direction at a constant period. The planar liquid crystal layer selectively reflects circularly polarized light in a predetermined wavelength range corresponding to the helical pitch p and in the same direction as the spiral winding direction. The selective reflection center wavelength λ that maximizes reflection is represented by the product of the average refractive index n of the liquid crystal and the helical pitch p (λ = n · p). The average refractive index n is determined by a liquid crystal material or a chiral agent contained in the liquid crystal layer. The helical pitch p is determined by the content of the chiral agent contained in the liquid crystal material. The selective reflection wavelength width has a lower limit of λ−Δλ and an upper limit of λ + Δλ. Here, Δλ is equal to the product Δn · p of the refractive index anisotropy Δn of the liquid crystal and the helical pitch p.

  When a predetermined voltage is applied to the planar liquid crystal, a focal conic state is established. In the focal conic state, the liquid crystal molecules form a helical structure having a helical axis in a direction parallel to the substrate. In the focal conic state, the selective reflectivity of light by the liquid crystal layer is lost, and most of the light is transmitted. After applying a large voltage to the liquid crystal in the focal conic state to bring it into a homeotropic state, when the electric field is suddenly reduced to 0, the planar state is restored.

  The liquid crystal panel 200r of this example is sealed with cholesteric liquid crystal that can selectively reflect the wavelength range of red light. The liquid crystal panel 200g is sealed with cholesteric liquid crystal capable of selectively reflecting the wavelength range of green light. The liquid crystal panel 200b is sealed with cholesteric liquid crystal that can selectively reflect the wavelength range of blue light. When the liquid crystal layers of the liquid crystal panels 200r, 200g, and 200b are all driven to the planar state, the light reflection / transmission plate 200 is in a reflection state that reflects incident light in almost the entire wavelength range of visible light. However, since only one circularly polarized light is reflected by the light reflecting / transmitting plate 200 of this example, the reflectance is about 50% at the maximum. In order to further increase the reflectance in the reflective state, a liquid crystal panel including liquid crystal layers with different spiral winding directions may be further laminated. In addition, when all of the liquid crystal layers of the liquid crystal panels 200r, 200g, and 200b are driven to the focal conic state, the light reflection / transmission plate 200 is in a transmission state that transmits incident light in almost the entire wavelength range of visible light. That is, the light reflection / transmission plate 200 can reversibly switch between the reflection state and the transmission state by controlling the driving voltage of each liquid crystal panel.

  In the lighting device 8 in the state shown in FIG. 15A (the light reflection / transmission plate 200 is in a reflection state), the light source unit 10 is sandwiched between the reflection plate 30 and the light reflection / transmission plate 200 in the reflection state. For this reason, the light emitted from the light source unit 10 is reflected directly or by the reflection plate 30 and the light reflection / transmission plate 200 in the reflective state, and is guided in the light source unit 10 toward the side surfaces 10c and 10d. The light that has reached the side surfaces 10c and 10d is emitted from the side surfaces 10c and 10d in a substantially horizontal direction and irradiated on the side wall surfaces 110a and 110b, as indicated by the left and right thick arrows in the drawing. Thereby, indirect illumination of the room using the reflected light on the side wall surfaces 110a and 110b can be performed.

  On the other hand, in the illumination device 8 in the state shown in FIG. 15B (the light reflection / transmission plate 200 is in a transmission state), most of the light emitted from the light source unit 10 is reflected directly or by the reflection plate 30 and reflected by the light reflection / transmission plate. 200 enters and transmits through the light reflecting / transmitting plate 200 in a transmitting state. The light that has passed through the light reflection / transmission plate 200 and has reached the light exit surface 20a is emitted from the light exit surface 20a substantially vertically downward as shown by the downward thick arrow in the drawing, and is irradiated indoors. Thereby, the indoor direct illumination using the direct light from the light source part 10 can be performed.

  As described above, according to the present embodiment, similarly to the first embodiment, the direction of light irradiation by the illumination device 8 can be easily achieved by switching the light reflection / transmission plate 200 between the reflection state and the transmission state. Can be switched about 90 °. Therefore, it is possible to easily switch between direct illumination using direct light from the light source unit 10 and indirect illumination using reflected light on the side wall surfaces 110a and 110b.

  In addition, the cholesteric liquid crystal used for the light reflection / transmission plate 200 in the present embodiment is considered to have high durability and reliability because there are many practical examples such as a reflective display and electronic paper.

[Tenth embodiment]
Next, the illuminating device by the 10th Embodiment of this invention is demonstrated using FIG. FIG. 16 shows a schematic cross-sectional configuration of the illumination device 9 according to the present embodiment. In the present embodiment, for example, the electro-deposition type electrochromic element shown in FIG. 3 (a method using hydrogenation of Mg—Ni alloy (FIG. 2) may be used) is used as the light control element 20. Yes. In an electrodeposition type electrochromic device, it takes several minutes to deposit silver salt on the substrate interface by applying a voltage. Therefore, depending on the voltage application time, a half mirror state that is an intermediate state between the transmission state and the reflection state can be generated. The half mirror state is a state in which the amount of silver salt deposited on the substrate interface is less than the reflection state and more than the transmission state.

  The light control element 20 according to the present embodiment is in a transmissive state when no voltage is applied, is in a reflective state (complete mirror state) when a voltage is applied for several minutes or more, and is in a half mirror state when a voltage is applied for several seconds. . When the voltage application is stopped, the deposited silver salt dissolves in the electrolyte layer. Therefore, when the half mirror state is maintained for a long time, the voltage application for about several seconds may be repeated intermittently. The light control element 20 in the half mirror state has a reflectance that is lower than the reflection state and higher than the transmission state. The light control element 20 in the half mirror state has a transmittance lower than that in the transmission state and higher than that in the reflection state.

  FIG. 16A shows the illumination device 9 when the light control element 20 is in a reflective state, and FIG. 16B shows the illumination device 9 when the light control element 20 is in a transmission state. FIG. 16C shows the illumination device 9 when the light control element 20 is in a half mirror state. In the state shown in FIG. 16A (the dimming element 20 is in the reflective state), indirect illumination of the room is performed using the reflected light on the side wall surfaces 110a and 110b, as in the state shown in FIG. be able to. In the state shown in FIG. 16B (the dimming element 20 is in the transmissive state), indoor direct illumination using direct light from the light source unit 10 can be performed as in the state shown in FIG. it can.

  In the state shown in FIG. 16C (the dimming element 20 is in a half mirror state), a part of the light emitted from the light source unit 10 (for example, about half) is dimmed directly or in a half mirror state with the reflector 30. The light is reflected by the element 20 and guided through the light source unit 10 toward the side surfaces 10c and 10d. The light that has reached the side surfaces 10c and 10d is emitted from the side surfaces 10c and 10d in a substantially horizontal direction and irradiated on the side wall surfaces 110a and 110b, as indicated by the left and right thick arrows in the drawing. Thereby, indoor indirect illumination can be performed using a part of the light emitted from the light source unit 10.

  In this state, a part (for example, about half) of the light emitted from the light source unit 10 is transmitted through the light control element 20 in a half mirror state. The light reaching the light emission surface 20a of the light control element 20 is emitted substantially vertically downward from the light emission surface 20a and irradiated indoors as indicated by a downward thick arrow in the figure. Thereby, indoor direct illumination can be performed using a part of the light emitted from the light source unit 10.

  As described above, according to the illumination device 9 of the present embodiment, in addition to being able to switch between indoor direct illumination and indirect illumination, direct illumination and indirect illumination can be performed simultaneously. For example, this is effective when it is desired to slightly brighten the room with indirect lighting or when it is desired to slightly darken the room with direct lighting. The ratio of the respective light amounts of the direct illumination and the indirect illumination in the half mirror state can be changed by adjusting the voltage application time of the light control element 20.

[Eleventh embodiment]
Next, the illuminating device by the 11th Embodiment of this invention is demonstrated using FIG. FIG. 17 shows a schematic cross-sectional configuration of the illumination device 210 according to the present embodiment. FIG. 17A shows the illumination device 210 when a light reflection / transmission plate 220 described later is in a reflective state, and FIG. 17B shows the illumination device 210 when the light reflection / transmission plate 220 is in a transmission state. Show. In addition, about the component which has the same function and effect | action as the illuminating device 1 by 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 17A and 17B, the illumination device 210 according to the present embodiment replaces the dimming element 20 of the first embodiment with a light reflection / transmission plate 220 (of the light reflection / transmission unit). Example). The light reflection / transmission plate 220 has a configuration in which three colloidal photonic crystal layers 220r, 220g, and 220b each including a colloidal photonic crystal (tunable photonic crystal) are laminated.

  In general, colloidal photonic crystals selectively reflect light in a predetermined wavelength range by Bragg reflection. The wavelength range of the selectively reflected light varies depending on the concentration of the solvent (ethanol) contained in the colloid photonic crystal. The colloidal photonic crystal selectively reflects the wavelength range of red light when the ethanol concentration is 70%, and selectively reflects the wavelength range of green light when the ethanol concentration is 80%. In the case of several tens% (for example, 20%), the wavelength range of blue light is selectively reflected. Colloidal photonic crystals are transparent to almost the entire wavelength range of visible light when the ethanol concentration is 60%.

  In the present embodiment, when the light reflection / transmission plate 220 is in a reflection state, the concentrations of ethanol contained in the colloid photonic crystal layers 220r, 220g, and 220b are controlled to 70%, 80%, and 20%, respectively. Thereby, the light reflection / transmission plate 220 reflects incident light in almost the entire wavelength range of visible light. On the other hand, when the light reflection / transmission plate 220 is set in the transmission state, the concentration of ethanol contained in the colloid photonic crystal layers 220r, 220g, and 220b is controlled to 60%. As a result, the light reflection / transmission plate 220 transmits incident light in substantially the entire wavelength range of visible light.

  When the light reflection / transmission plate 220 is in the reflection state, as shown in FIG. 17A, the light emitted from the light source unit 10 is reflected directly or by the reflection plate 30 and the light reflection / transmission plate 220 in the reflection state. The light source 10 is guided toward the side surfaces 10c and 10d. The light that has reached the side surfaces 10c and 10d is emitted from the side surfaces 10c and 10d in a substantially horizontal direction and irradiated on the side wall surfaces 110a and 110b, as indicated by the left and right thick arrows in the drawing. Thereby, indirect illumination of the room using the reflected light on the side wall surfaces 110a and 110b can be performed.

  When the light reflection / transmission plate 220 is in a transmission state, as shown in FIG. 17B, most of the light emitted from the light source unit 10 is reflected directly or by the reflection plate 30 and enters the light reflection / transmission plate 220. Then, the light is transmitted through the light reflection / transmission plate 220 in the transmission state. The light that has passed through the light reflection / transmission plate 220 and has reached the light emission surface 20a is emitted from the light emission surface 20a in a substantially vertical downward direction and irradiated indoors, as indicated by a downward-facing thick arrow in the figure. Thereby, the indoor direct illumination using the direct light from the light source part 10 can be performed.

  As described above, according to the present embodiment, similarly to the first embodiment, the direction of light irradiation by the illumination device 210 can be easily achieved by switching the light reflection / transmission plate 220 between the reflection state and the transmission state. Can be switched about 90 °. Therefore, it is possible to easily switch between direct illumination using direct light from the light source unit 10 and indirect illumination using reflected light on the side wall surfaces 110a and 110b.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, in the above embodiment, the lighting device is attached to the concave portion 110, and the indirect illumination is performed using the reflected light from the side wall surfaces 110a and 110b of the concave portion 110, but the lighting device is attached to the ceiling surface 100 and the ceiling surface. Indirect illumination may be performed using the reflected light at 100.

  Moreover, in said embodiment, the color of the illumination light of an illuminating device is not limited to white. For example, as shown in FIG. 18A, a plurality of sets of LEDs 240r, 240g, and 240b that emit light of each color of R, G, and B are used for the light source unit 10, and the emission intensity of the LEDs 240r, 240g, and 240b is set for each color. By controlling to, the illumination light of the illumination device can be set to any color other than white.

  Further, as shown in FIG. 18B, a light source that emits white light is used for the light source unit 10 and, for example, an electrochromic element that can switch between a colored state and a colorless and transparent state (see Patent Document 4) By providing an electrophoretic (electrophoretic) element or the like as the color filter layer 250 on the light emitting surface 20a side of the light control element 20, the illumination light of the illumination device can be set to any color other than white.

  Moreover, in the said embodiment, although the illuminating device is provided in the indoor ceiling (refer FIG. 19 (a), (b)), an indoor wall (refer FIG. 20 (a), (b)), floor ( 21 (a) and (b)), between the wall and the ceiling (or floor) (see FIGS. 22 (a) and (b)), and the like.

  Further, the technical features (configuration requirements) described in each of the above embodiments can be combined with each other, and a new technical feature can be formed by combining them.

  The present invention can be widely used in the field of lighting devices.

1, 2, 3, 4, 5, 6, 6, 7, 8, 9, 208, 210, 212 Illumination device 10 Light source 10a, 10b Surface 10c, 10d Side surface 20 Dimming element 20a Light exit surface 30 Reflecting plate 30a Openings 41, 51, 52, 141, 142, 143, 144, 146, 147, 230 Transparent substrates 42, 53, 54 Transparent conductive film 43 Ion storage layer 44 Solid electrolyte layer 45 Buffer layer 46 Catalyst layer 47 Dimming mirror layer 48, 57 Power circuit 55 Sealing material 56, 145 Electrolyte layer 58 Mirror surface layer 60, 61, 62 Scattering films 71, 72 Refractive index matching layer (adhesive layer)
80 Movable mirror 81 Rotating shaft 91 Light guide part 92, 131, 232, 240r, 240g, 240b LED
93 Scattering unit 100 Ceiling surface 110 Recesses 110a and 110b Side wall surfaces 120a and 120b Space 132 Scattering layer 133 Air layer 150 Fluorescent tube 151 Electrode 160 Light emitting sheet 161 Cover 170 Prism 170a Light exit surface 180 Light duct 181 Light collecting unit 182 Light guide unit 183 Light emission part 184 Gap 190 Indoor 200, 220 Light reflection / transmission plate 200r, 200g, 200b Liquid crystal panel 220r, 220g, 220b Colloid photonic crystal layer 231 Phosphor layer 233 Phosphor dispersion substrate 250 Color filter layer

Claims (5)

A light source unit that emits light in a planar shape;
A light guide unit disposed on the light emitting surface side of the light source unit, comprising a pair of surfaces and side surfaces formed around the surface, and a light guide unit that emits light from at least one of the surfaces and the side surface;
The light guide unit is arranged on the other side of the light source unit, and switches between a reflective state that reflects light from the surface of the light guide unit and a transmissive state that transmits light from the surface of the light guide unit. An illuminating device comprising: a possible light reflection / transmission unit. The lighting device according to claim 1.
An illumination device, further comprising: a light reflecting portion that is disposed on the other side of the light emitting surface of the light source portion and reflects light from the light source portion. The lighting device according to claim 1 or 2,
The light reflection / transmission part includes an electrochromic element, a movable mirror, a cholesteric liquid crystal, or a tunable photonic crystal. In the illuminating device as described in any one of Claim 1 to 3,
At least one of the adjacent interfaces of the light source unit, the light reflection / transmission unit, the light guide unit, and the light reflection unit is made of a material having a refractive index in a range in which the refractive index of the adjacent component is the upper limit or lower limit. An illumination device comprising a refractive index matching layer. In the illuminating device as described in any one of Claim 1-4,
An illumination device comprising: a light scattering portion that scatters light at least in either a surface or a side surface direction from which the light is emitted.

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