JP2014026841A - Lighting apparatus and lighting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting apparatus capable of suppressing a sense of incompatibility that a resident has as much as possible as a lighting apparatus which achieves irradiation just like top light when natural light is collected and with as uniform illumination light as possible when a light source is turned on, and a lighting mechanism.SOLUTION: Natural light radiated from the sun SN passes through a duct DC to enters a light guide plate PT from a natural light incidence surface NP of the light guide plate, and is emitted from an under surface (first main surface) of the light guide plate to light up the inside of a room below a lighting apparatus IL. Artificial light emitted from an artificial light source OS, on the other hand, is made incident from an artificial light incidence surface AP. The artificial light entering the light guide plate is totally reflected again and again by an upper surface or a lower surface of the light guide plate to be guided in the light guide plate as shown by an arrow, for example, but scattered to change in reflection direction when impinging on light path deflection means GR provided on the upper surface of the light guide plate, and thereafter the artificial light impinging on the lower surface of the light guide plate at an angle close to the vertical is transmitted as it is to light up the inside of the room below the lighting apparatus.

Description

  The present invention relates to a hybrid illumination device and an illumination mechanism that can illuminate using natural light and artificial light.

  There is a known daylighting window that can be attached to the roof or ceiling of a building. The purpose of the daylighting window is to illuminate the room using sunlight incident from the daylighting window during daylight hours when sufficient sunlight is obtained. Therefore, since it is impossible to illuminate using sunlight when the sun is hidden such as when it is raining or cloudy, or at night, a separate artificial lighting device is required. However, installing the lighting window and the lighting device separately increases the installation cost and generally limits the position suitable for lighting in the room, so either the lighting window or the lighting device is placed at the optimal position. There is a problem of whether or not it looks, and it does not look good.

  In order to solve such a problem, Patent Literature 1 proposes an illumination device integrated with a daylighting window. The illumination device of Patent Document 1 includes a fluorescent lamp provided around an opening of a lighting window such as a ceiling, and a stacked light guide plate extending from the fluorescent lamp toward the opening.

JP 05-2906 A

  However, the prior art disclosed in Patent Document 1 has a complicated and bulky structure because a plurality of light guide plates having different shapes are stacked, and the loss of light emitted from the fluorescent lamp is large, and the indoor side is Fluorescent illumination light that travels does not have a uniform illuminance, which may lead to a sense of incongruity among residents. In addition, dust and the like are likely to collect at the mating portions of the laminated light guide plates, which may cause mold and the like, which is not preferable in terms of interior design. In addition, since sunlight taken in from the daylighting window has a very high light intensity compared to the light from the fluorescent lamp, there is a strong possibility that the resident will feel uncomfortable.

  The present invention has been made in view of such problems, and has a compact structure, excellent design, and no light path deflecting means on the natural light incident surface, so that it feels like a top light when taking natural light. As an illuminating device that can capture natural light with low loss and perform highly efficient lighting, and can illuminate the illumination light as uniformly as possible when the light source is lit, it can perform illumination that can suppress the sense of discomfort of residents as much as possible It aims to provide a lighting mechanism.

The illumination device according to claim 1 is emitted from a second main surface including a natural light incident surface on which light emitted from a natural light source is incident, a first main surface facing the second main surface, and an artificial light source. A light guide plate having an artificial light incident surface for incident light, and the artificial light source,
The second main surface is provided with an optical path deflecting unit that causes scattering when artificial light guided through the light guide plate is incident on a region other than the natural light incident surface, and the natural light incident surface includes: The optical path deflecting means is not provided,
The light emitted from the natural light source is incident from the natural light incident surface, passes through the light guide plate, and is emitted from the first main surface.
The light emitted from the artificial light source is incident from the artificial light incident surface, guided through the light guide plate, and then emitted from the first main surface via the optical path deflecting means. Features.

  FIG. 1 is a schematic diagram for explaining the principle of the present invention. In FIG. 1, an illumination device IL is attached to the lower end of a duct DC formed on the ceiling CL of the building. The illumination device IL includes a transparent light guide plate PT and an artificial light source OS. On the upper surface (second main surface) of the light guide plate PT, optical path deflecting means that causes scattering when artificial light that guides the light guide plate PT is incident, except within the range of the duct DC (natural light incident surface NP). GR is provided. The side surface of the light guide plate PT is an artificial light incident surface AP.

  During the day, natural light radiated from the sun SN passes through the duct DC and enters the light guide plate PT from the natural light incident surface NP of the light guide plate PT, and then from the lower surface (first main surface) of the light guide plate PT. The light is emitted to illuminate the room below the illumination device IL. On the other hand, the artificial light emitted from the artificial light source OS enters from the artificial light incident surface AP. The artificial light that has entered the light guide plate PT is guided in the light guide plate PT by repeating total reflection on the lower surface or the upper surface of the light guide plate PT, as shown by an arrow as an example. When entering the provided optical path deflecting means GR, it is scattered and the reflection direction changes. Thereafter, the artificial light incident on the lower surface of the light guide plate PT at an angle close to the vertical is transmitted as it is to illuminate the room below the illumination device IL.

  According to the present invention, the ceiling CL is attached to the illumination device IL having a thickness of about one light guide plate, so that it is compact and easy to clean, and does not impair the interior design. In addition, since the optical path deflecting means GR is provided on the second main surface other than the natural light incident surface NP, it is possible to efficiently illuminate the room with only natural light even when it is cloudy or dusk without interfering with natural light. Can save energy. On the other hand, the artificial light incident on the light guide plate PT is emitted from the first main surface with the light distribution controlled via the optical path deflecting means GR, so that uniform illumination light can be obtained and the resident feels uncomfortable. There is little fear.

The “optical path deflecting means” is sufficient if it has a function of diffusing the light incident from the inside of the light guide plate, which is integral or in close contact with the second main surface (without sandwiching the air layer). Any structure is acceptable. The haze value can be substituted for the characteristics of the optical path deflecting means. “An optical path deflecting means is provided” means that the second main surface has a diffusing function so that its haze value is 10% or more, preferably 90% or less. More preferably, the haze value is 10% or more and 50% or less. On the other hand, “no optical path deflecting means is provided” means that the haze value is less than 10% even if the second main surface is left in a mirrored state or has a diffusion function. It means stopping. Since the haze value when an acrylic surface suitable as a material for the light guide plate is in a mirror state is about 0.73%, the optical path deflecting means is not provided in that state. The haze value can be calculated by the following formula (JIS-K-7105, JIS-K-7136).
Haze (%) = Td / Tt × 100
Td: Diffuse transmittance
Tt: Total light transmittance

  The “natural light source” is, for example, the sun, and the “artificial light source” is a light source that emits light using electricity as an energy source, and is preferably a surface light source such as an LED or an organic EL from the viewpoint of energy saving.

  According to a second aspect of the present invention, in the invention according to the first aspect, the light path deflecting unit is configured by applying a diffusing agent containing diffusing particles to the second main surface. And

By using a diffusing agent containing diffusing particles that diffuse incident light as the optical path deflecting means, a two-dimensional pattern of diffusing particles can be arbitrarily formed on the second main surface, and more uniform artificial light Can be achieved. The diffusing agent containing diffusing particles means a mixture of diffusing particles in some solvent. Examples of such a diffusing agent include, in addition to various pigment-based inks, a diffusing agent mixed with titanium oxide (TiO ₂ ), calcium carbonate (CaCO ₃ ), resin fine particles, and the like as diffusing particles.

  According to a third aspect of the present invention, there is provided the lighting device according to the first aspect, wherein the optical path deflecting unit is configured by attaching a sheet containing diffusing particles to the second main surface. .

  For example, the same effect can be realized by applying a diffusing agent containing diffusing particles to the sheet and then applying the diffusing agent to the second main surface. The diffusion particles may be kneaded directly into the sheet.

  According to a fourth aspect of the present invention, in the invention according to the second or third aspect, the density of the diffusing particles increases as the distance from the artificial light source increases.

  The higher the density of the diffusing particles, the higher the degree of diffusion of the incident light. Therefore, by increasing the density of the diffusing particles at a position far from the artificial light source where the artificial light is difficult to reach, a more uniform illuminance of artificial light is realized. it can. Here, the density of the diffusing particles is a concept that includes both the density of the diffusing particles in the diffusing agent (the amount of the diffusing particles mixed in a predetermined volume of solvent) and the occupation density of the diffusing particles with respect to the light guide plate. For example, when the density of the diffusion particles is increased, referring to FIG. 2, the arrangement pitch p of the diffusion particles GR is equal to the distance from the light source OS, but the diameter d increases (a) This includes both cases where the diameter d of the diffusing particles GR is equal but the pitch p decreases (b). The smaller the pitch p or the larger the diameter d, the higher the density.

  According to a fifth aspect of the present invention, in the invention according to the first aspect, the light path deflecting unit is configured by forming a plurality of concave portions on the second main surface by machining. And

  By forming a plurality of recesses on the second main surface, incident light can be diffused, and therefore, it can function as the optical path deflecting means. Such recesses include grooves and holes. Examples of machining include laser machining and cutting.

  The lighting device according to claim 6 is characterized in that, in the invention according to claim 5, the pitch of the recesses decreases as the distance from the artificial light source increases.

  Since the degree of diffusion of incident light increases as the pitch of the recesses decreases, more uniform artificial light illuminance can be realized by reducing the pitch of the recesses at a position farther than the artificial light source where the artificial light does not easily reach. .

  According to a seventh aspect of the present invention, in the invention according to the fifth or sixth aspect, the depth of the concave portion increases as the distance from the artificial light source increases.

  As the depth of the concave portion increases, the degree of diffusion of incident light increases. Therefore, by increasing the depth of the concave portion at a position farther than the artificial light source that is difficult for artificial light to reach, a more uniform illuminance of artificial light can be obtained. realizable.

  The illumination device according to claim 8 is the invention according to any one of claims 1 to 7, wherein a reflection member is provided in a region of the second main surface where the optical path deflecting unit is provided. It is characterized by.

  By providing a reflecting member in the region where the optical path deflecting means is provided, the light leaking out from the optical path deflecting means is reflected and re-entered into the light guide plate, thereby improving the light utilization efficiency. it can.

  The lighting device according to claim 9 is the invention according to any one of claims 1 to 8, wherein the artificial light incident surface is a side surface of the light guide plate, and the side surface of the light guide plate close to the artificial light source. A reflective member is provided on the side surface facing the surface.

  By using the reflecting member to reflect light leaking from the side surface opposite to the artificial light source and again entering the light guide plate, the light utilization efficiency can be increased.

  The lighting device according to claim 10 is the invention according to any one of claims 1 to 8, wherein the artificial light incident surface is a side surface of the light guide plate, and the artificial light source sandwiches the light guide plate. It is arranged to face both side surfaces.

  The illuminance of the artificial light can be increased by arranging the artificial light source so as to face both side surfaces with the light guide plate in between.

  According to an eleventh aspect of the present invention, in the invention according to the ninth or tenth aspect, the artificial light incident surface has a V-shaped groove shape.

  Since the light emitted from the artificial light source can be refracted by the V-shaped groove-shaped incident surface and directed to the first main surface or the second main surface in the light guide plate, desired light distribution characteristics can be obtained. While ensuring uniform illumination light, the light traveling back and forth within the light guide plate can be reduced to reduce loss.

  The illuminating device according to claim 12 is characterized in that, in the invention according to any one of claims 1 to 8, the artificial light incident surface is a part of the first main surface.

  Thereby, the width | variety of the said illuminating device can be suppressed and it can be made compact.

  According to a thirteenth aspect of the present invention, in the invention according to any one of the first to twelfth aspects, a first diffusion plate is provided to face the natural light incident surface.

  Sunlight as natural light has a higher intensity than artificial light, and when sunlight is directly taken into a room, glare or the like may occur and residents may feel glare. Therefore, by providing the first diffusion plate facing the natural light incident surface, it is possible to diffuse the incident natural light and suppress glare.

  A lighting device according to a fourteenth aspect is the lighting device according to the thirteenth aspect, wherein a second diffusion plate is provided to face the first main surface, and the haze value of the first diffusion plate is the first value. It is characterized by being larger than the haze value of the diffusion plate of 2.

  By providing the second diffuser plate facing the first main surface, a diffusion effect is given to the artificial light emitted from the first main surface, illumination unevenness is suppressed, and illumination light that can be illuminated over a wide range is obtained. Can do. If the haze value of the first diffuser plate is larger than the haze value of the second diffuser plate, sunlight as natural light is first passed through the first diffuser plate having a large haze value. When the light is diffused and transmitted through the light guide plate and then emitted by passing through the second diffuser plate having a small haze value, illumination light that is gentler to the eyes can be obtained. Thereby, the illumination of natural light and the illumination of artificial light can be brought close to each other, and a sense of incongruity can be suppressed. As an example, a haze value of a diffuser plate with a diffusivity of 20 ° is about 92%.

  The illumination device according to claim 15 is characterized in that, in the invention according to any one of claims 1 to 14, the artificial light source has a plurality of different emission colors.

  When the artificial light source has a plurality of different emission colors, for example, the emission color can be changed in accordance with the color temperature of natural light that changes in accordance with the weather or time of day, and an uncomfortable feeling of artificial lighting can be suppressed.

  The illumination device according to claim 16 is characterized in that, in the invention according to any one of claims 1 to 15, an ultraviolet cut filter is provided on the natural light incident surface.

  By providing the ultraviolet light cut filter on the natural light incident surface, the ultraviolet light component contained in the natural light is removed, and for example, when the light guide plate is formed of a resin such as acrylic, the deterioration can be suppressed.

The illumination device according to claim 17 is the invention according to any one of claims 1 to 16, wherein the maximum dimension of the natural light incident surface is A (mm), and the maximum dimension of the second main surface is B (mm). The following formula is established.
0.5 <A / B <0.7 (1)

  By satisfying the expression (1), the light quantity of natural light and artificial light can be made uniform, and an illuminating device that suppresses a sense of incongruity can be provided.

  An illumination mechanism according to an eighteenth aspect includes a lighting device according to any one of the first to seventeenth aspects, a sensor that detects the intensity of the natural light, and dimming the artificial light source according to a signal from the sensor. And a control device for color control.

  For example, when it is determined that the intensity of natural light is high such as during the day based on the signal from the sensor, the control device can save energy by controlling the artificial light source to be off. On the other hand, based on the signal from the sensor, when it is determined that the intensity of natural light has decreased, such as at dusk, the control device can automatically turn on the illumination by turning on the artificial light source, It is possible to avoid bothering the user.

  The illumination device according to the present invention includes a light guide plate and an artificial light source. As the artificial light source, for example, an LED (Light Emitting Diode) light source can be used.

  Various LED light sources can be used, but white LEDs are preferably used, but LEDs having different emission colors may be used.

  As the white LED, a combination of a blue LED chip and a phosphor such as a YAG phosphor that emits yellow light by blue light emitted from the blue LED chip is preferably used, but a blue LED chip, a green LED chip, and a red LED are used. It may be a white LED that forms white light in combination with a chip. As white LED, what was described, for example in Unexamined-Japanese-Patent No. 2008-231218 can be used, However, It is not restricted to this.

  The white LED light source is preferably composed of an LED chip and a phosphor layer formed on the LED chip so as to cover the LED chip. As an example of the LED chip, light having a first predetermined wavelength is emitted, and for example, blue light is emitted. However, the wavelength of the LED chip and the wavelength of the emitted light from the phosphor are not limited, and the synthesized light is white light because the wavelength of the emitted light from the LED chip and the wavelength of the emitted light from the phosphor are complementary. Any combination can be used.

  In addition, as such an LED chip, a well-known blue LED chip can be used. As the blue LED chip, any existing one including InxGa1-xN system can be used. The emission peak wavelength of the blue LED chip is preferably 440 to 480 nm. In addition, as a form of the LED chip, the LED chip is mounted on the substrate and directly radiated upward or sideward, or the blue LED chip is mounted on a transparent substrate such as a sapphire substrate, and bumps are formed on the surface thereof. Any form of LED chip, such as a so-called flip chip connection type, in which it is formed and turned over and connected to an electrode on a substrate, can be applied.

  The phosphor layer preferably has a phosphor that converts light having a first predetermined wavelength emitted from the LED chip into a second predetermined wavelength. As an example, there is one that converts blue light emitted from an LED chip into yellow light.

  The phosphor used for such a phosphor layer uses an oxide or a compound that easily becomes an oxide at a high temperature as a raw material of Y, Gd, Ce, Sm, Al, La and Ga, and converts them into a stoichiometric amount. The raw material is obtained by thoroughly mixing in a theoretical ratio. Alternatively, a coprecipitated oxide obtained by calcining a solution obtained by coprecipitation of oxalic acid with a solution obtained by dissolving a rare earth element of Y, Gd, Ce, and Sm in an acid at a stoichiometric ratio, and aluminum oxide and gallium oxide. Mix to obtain a mixed raw material. An appropriate amount of fluoride such as ammonium fluoride is mixed with this as a flux and pressed to obtain a molded body. The compact can be packed in a crucible and fired in air at a temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a sintered body having the phosphor emission characteristics.

  The LED light source is preferably a high-power LED light source. Here, the high-power LED light source can be constituted by an LED having an output of 0.5 watts or more.

  The light guide plate is preferably made of glass or plastic. For example, polycarbonate or acrylic can be used as the plastic constituting the lens.

  According to the present invention, it has a compact configuration, excellent design, and no light path deflecting means on the natural light incident surface, so that natural light can be taken in with a low light loss as if it were a top light when taking natural light. As an illuminating device that can perform efficient daylighting and can emit illumination light as uniform as possible when the light source is turned on, an illuminating device and an illuminating mechanism that can perform illumination that can suppress discomfort to the occupants as much as possible can be provided.

It is a figure which shows the principle of this invention. It is a figure which shows the density of an optical path deflection | deviation means. It is the schematic which shows the state which attached the illuminating device concerning 1st Embodiment to the building. 1 is a perspective view of a lighting device 10. FIG. FIG. 3 is an exploded view of the lighting device 10. FIG. 3 is an enlarged perspective view of a cross section of the lighting device 10. It is the schematic which looked at the illuminating device 10 from the side. It is a top view which shows the modification of this Embodiment. It is a partial cross section figure which shows another modification of this Embodiment. It is a top view which shows another modification of this Embodiment. It is a partial cross section figure which shows another modification of this Embodiment. It is a partial cross section figure which shows another modification of this Embodiment. It is a figure which shows the illumination mechanism concerning 2nd Embodiment. It is the figure which looked at the illuminating device concerning the modification of this Embodiment from the natural light incident surface side.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

(First embodiment)
FIG. 3 is a schematic view showing a state in which the lighting device according to the present embodiment is attached to a building. In FIG. 3, a lighting device 10 is attached to the ceiling 4 of the building 1. The roof 1a of the building 1 is provided with a transparent dome-shaped daylighting portion 2, and sunlight SL incident thereon is illuminated through a hollow duct 3 (inner diameter φ) extending through the building 1. 10 is guided.

  FIG. 4 is a perspective view of the lighting device 10, and FIG. 5 is an exploded view of the lighting device 10. FIG. 6 is an enlarged perspective view of a cross section of the lighting device 10, and FIG. 7 is a schematic view of the lighting device 10 as viewed from the side. Here, “upper” means the upper side in the direction of gravitational acceleration, and “lower” means the lower side in the direction of gravitational acceleration.

  As shown in FIGS. 5 and 6, the lighting device 10 includes an LED light source 11 as a natural light source, a light guide plate 12, a first diffusion plate 13, a second diffusion plate 14, a plate-like reflection member 15, And a frame 16 for holding them and attaching them to the ceiling 4. In addition, as shown in FIG. 6, if the design cover CV is arrange | positioned through the spacer SP under the 2nd diffuser plate 14, design property will improve more.

  The LED light source 11 includes an elongated substrate 11b disposed along the side surface of the light guide plate 12, and a plurality of light emitting units 11a disposed at equal intervals on the substrate 11b. The substrate 11b is fixed to the frame 16.

  The upper surface of the square light guide plate 12 is the second main surface 12a, the lower surface is the first main surface 12b, and the four side surfaces 12c arranged facing the light emitting portion 11a constitute the artificial light incident surface. . A circular natural light incident surface 12d having a diameter φ is formed at the center of the second main surface 12a. A diffusing agent DF containing diffusing particles as optical path deflecting means is applied to the entire second main surface 12a excluding the natural light incident surface 12d (range shown by hatching in FIG. 5). On the other hand, the diffusing agent DF is not applied to the natural light incident surface 12d. Instead of the diffusing agent, fine dot-like printing or the like may be performed.

When the diameter that is the maximum dimension of the natural light incident surface 12d is φ (= A) (mm) and the diagonal size that is the maximum dimension of the second main surface 12a is B (mm), the following expression is established. In the present embodiment, φ / B = 0.56.
0.5 <φ / B <0.7 (1)

  A first diffusion plate 13 having an outer diameter φ is disposed adjacent to the natural light incident surface 12d. In addition, a reflecting member 15 is provided adjacent to the second main surface 12a outside the natural light incident surface 12d. That is, the first diffusion plate 13 is provided in the circular opening 15 a of the reflecting member 15. On the other hand, the 2nd diffuser plate 14 is arrange | positioned adjacent to the 1st main surface 12b. The haze value of the first diffusion plate 13 is larger than the haze value of the second diffusion plate 14. Note that an ultraviolet cut filter may be provided on the first diffusion plate 13. As an example, the first diffusion plate 13 is a diffusion plate having a diffusivity of 20 ° and a haze value of about 92%. The second diffuser plate 14 is smaller than that.

  The operation of this embodiment will be described. In FIG. 3, natural light SL radiated from the sun SN during the day is incident from the daylighting unit 2 and travels along the duct 3. Further, in FIG. 7, the light passes through the first diffusion plate 13 of the lighting device 10 and enters the light guide plate 12 from the natural light incident surface 12 d. Then, it radiates | emits from the 1st main surface 12b of the light-guide plate 12, permeate | transmits the 2nd diffuser plate 14, and illuminates the room below the illuminating device 10. FIG.

  On the other hand, artificial light emitted from the LED light source 11 enters from the side surface 12 c of the light guide plate 12. As an example, artificial light incident on the light guide plate 12 is guided through the light guide plate 12 by repeating total reflection on the lower surface or the upper surface of the light guide plate 12 as indicated by an arrow in FIG. When the light is incident on the diffusing particles of the diffusing agent DF applied to the second main surface 12a, the reflection direction is changed by scattering (the light that has passed through the diffusing agent DF and leaked to the outside is reflected by the reflecting member 15, Return to the light guide plate 12 again). After that, the artificial light incident on the first main surface 12b of the light guide plate 12 at an angle close to the vertical is lost as the total reflection condition is broken, and thus is transmitted as it is, further transmitted through the second diffusion plate 14, and below the illumination device 10. The interior of the room is illuminated.

  Since sunlight SL as natural light is higher in intensity than LED light, when sunlight SL is directly taken into a room, glare or the like may occur and the resident may feel glare. Therefore, in the present embodiment, by providing the first diffusion plate 13 on the natural light incident surface 12d, it is possible to diffuse the incident natural light and suppress glare.

  Furthermore, by providing the second diffusing plate 14 on the first main surface 12b, it is possible to give a diffusing effect to the LED light emitted from the first main surface 12b and to obtain illumination light that is gentler to the eyes. Moreover, if the haze value of the 1st diffuser plate 13 is larger than the haze value of the 2nd diffuser plate 14, sunlight SL as natural light shall first pass through the 1st diffuser plate 13 with a large haze value. Thus, when the light is diffused and transmitted through the light guide plate 12 and then emitted by passing through the second diffusion plate 14 having a small haze value, illumination light that is gentler to the eyes can be obtained. Thereby, the illumination of sunlight and the illumination of LED light can be brought close, and a sense of incongruity can be suppressed.

  FIG. 8 is a diagram showing a modification of the present embodiment, but the diffusion particles are schematically drawn. In the above-described embodiment, the uniform density diffusion particles GR are arranged on the second main surface 12a (excluding the natural light incident surface 12d) coated with the diffusing agent DF. On the other hand, in the example shown in FIG. 8, the density of the diffusion particles GR is increased as the distance from the LED light source 11 increases.

  More specifically, in the example of FIG. 8A, since the LED light source 11 is disposed to face one side surface 12c (left side in the drawing) of the light guide plate 12, the density of the diffusing particles of the diffusing agent DF. Increases as the distance from the LED light source 11 increases (to the right). Thereby, it is possible to emit a relatively large amount of light even on the side farther than the LED light source 11 and difficult to reach the LED light, and to emit light that is nearly uniform as a whole.

  In the example of FIG. 8B, since the LED light source 11 is disposed opposite to the two side surfaces 12c (left and right sides in the figure) of the light guide plate 12, the density of the diffusing particles of the diffusing agent DF is determined by the LED light source. As the distance from 11 increases (from both sides to the center), the line increases symmetrically. Further, in the example of FIG. 8C, the LED light source 11 is disposed so as to face the four side surfaces 12 c (entire circumference) of the light guide plate 12. As it moves away from 11 (from the whole circumference to the center), it increases substantially point-symmetrically. In any example, it is desirable to provide a reflecting plate on the side surface 12c where the LED light source 11 is not provided, as will be described later.

  FIG. 9 is a diagram showing another modification of the present embodiment. In this example, as the optical path deflecting means, a plurality of concave grooves GV are formed on the second main surface 12a (excluding the natural light incident surface 12d) of the light guide plate 12 by laser processing. In the example of FIG. 9A, the cross-sectional shapes (depth, etc.) of the concave grooves GV are equal, and the pitch p of the adjacent concave grooves GV is made smaller as the distance from the LED light source 11 increases.

  The smaller the pitch p of the concave grooves GV, the higher the degree of diffusion of incident light. Therefore, by reducing the concave groove pitch p at a position far from the LED light source 11 where the artificial light is difficult to reach, more uniform artificial light illuminance can be obtained. Can be realized.

  On the other hand, in the example of FIG. 9B, the pitch of the concave grooves GV is equal to p, and the depth Δ is increased as the distance from the LED light source 11 increases. As the depth Δ of the concave groove GV increases, the degree of diffusion of incident light increases. Therefore, by increasing the depth Δ of the concave groove GV at a position farther than the LED light source 11 where the artificial light does not easily reach, a more uniform artificial Light intensity can be achieved.

  FIG. 10 is a diagram showing another modification of the present embodiment. In the embodiment described above, the LED light source 11 is disposed so as to face the entire side surface 12 c of the light guide plate 12. On the other hand, in the example of FIG. 10, the LED light source 11 is disposed facing only a part of the side surface 12c.

  More specifically, in the example of FIG. 10A, the LED light source 11 is disposed to face one side surface 12 c of the light guide plate 12. A reflecting plate 17 is arranged to face the remaining three side surfaces 12c. Even when the light incident on the light guide plate 12 from the LED light source 11 is emitted from the opposite side surface 12c, the light is reflected by the reflection plate 17 so as to enter the light guide plate 12 again and be guided. .

  In the example of FIG. 10B, two sets of LED light sources 11 are arranged to face the two side surfaces 12 c of the light guide plate 12. The reflection plate 17 is disposed to face the remaining two side surfaces 12c. Further, in the example of FIG. 10C, the LED light source 11 is disposed to face the three side surfaces 12 c of the light guide plate 12. The reflection plate 17 is arranged to face the remaining one side surface 12c.

  FIG. 11 is a diagram showing another modification of the present embodiment. In the embodiment described above, the side surface 12c of the light guide plate 12, which is the artificial light incident surface, is planar, but in this example, it is V-shaped as shown in the figure. As a result, the light emitted from the LED light source 11 can be refracted by the V-shaped groove-shaped artificial light incident surface and directed to the first main surface 12b or the second main surface 12a in the light guide plate 12. While ensuring uniform light distribution characteristics while ensuring light distribution characteristics, it is possible to reduce light traveling back and forth within the light guide plate 12 and to suppress loss. Note that the V-groove may have an asymmetrical shape.

  FIG. 12 is a diagram showing another modification of the present embodiment. In this example, the LED light source 11 is opposed to the vicinity of the periphery of the first main surface 12b. The light emitted from the LED light source 11 enters from the first main surface 12b, is reflected by the inclined side surface 12c ', and then travels toward the first main surface 12b and the second main surface 12a. Thereafter, light is guided in the same manner as in the above-described embodiment. A reflecting member 17 may be provided opposite to the inclined surface 12c 'as indicated by a dotted line.

(Second Embodiment)
FIG. 13 is a diagram illustrating an illumination mechanism according to the second embodiment. In FIG. 13, an external light sensor S is provided adjacent to the daylighting unit 2 of the building 1, and a control device CONT that controls on / off of the LED light source 11 is provided. The illuminating device 10 is the same as that of embodiment mentioned above.

  When the illumination mechanism determines that the intensity of natural light is high, such as during the day, based on a signal from the external light sensor S, the control device CONT can save energy by controlling the LED light source 11 to be off. On the other hand, when it is determined that the intensity of natural light has decreased, such as at dusk, based on the signal from the external light sensor S, the control device CONT automatically turns on the illumination by turning on the LED light source 11. This can be done without bothering the user.

  FIG. 14 is a diagram illustrating a modification of the lighting device 10. In the illuminating device in the above-described embodiment, the diffusing agent as the optical path deflecting unit is applied to the edge of the second main surface of the rectangular light guide plate. In this case, from the LED light source emitted indoors The outer shape of the illumination light beam is rectangular over the entire surface of the light guide plate 14. However, considering the interior design, there is also a demand to have a range by the illumination light beam outline. The modifications described below can meet such a demand.

  More specifically, in the modification shown in FIG. 14A, the diffusing agent DF is formed in a ring shape on the second main surface 12a of the light guide plate 12 so as to surround the periphery of the circular natural light incident surface 12d. It has been applied. Thereby, the external shape of the illumination light beam emitted from the first main surface on the back side is circular.

  Further, in the modification shown in FIG. 14B, the diffusing agent DF is applied in a circular shape on the second main surface 14a of the light guide plate 12 so as to surround the square natural light incident surface 12d. In the modification shown in FIG. 14C, the light guide plate 12 has a circular outer shape, and the diffusing agent DF is applied in a ring shape so as to surround the circular natural light incident surface 12d. Further, in the modification shown in FIG. 14D, the light guide plate 12 has a circular outer shape, and the diffusing agent DF is applied in a square shape so as to surround the circular natural light incident surface 12d. Thereby, even if the illuminating device is circular, it is possible to emit an illumination light beam having a rectangular outer shape. In addition to the above, various shapes can be employed. About another structure, it is the same as that of embodiment mentioned above.

  As yet another example, the LED light source 11 can be configured to have a plurality of different emission colors (red, blue, green). In such a case, the control device CONT performs color mixing by turning on one of the LED light sources 11 having different emission colors according to the color temperature of natural light that changes according to, for example, the weather or time, and thereby performs external color mixing. Lighting close to light can be realized.

  In addition, it is not restricted to the above embodiment, The light-guide plate 12 can be cut out along the diameter (phi) of the duct 3, and a cylindrical opening can be provided, and a reflecting plate can also be provided in the inner periphery of opening. Thereby, more uniform illumination of LED light can be realized while taking in sunlight.

  The present invention is not limited to the embodiments described in the specification, and other embodiments and modifications are apparent to those skilled in the art from the embodiments and ideas described in the present specification. It is. The description and examples are for illustrative purposes only, and the scope of the invention is indicated by the following claims. For example, the shape of the natural light incident surface is not limited to a circle, but may be a polygonal shape or a slit shape. Further, since no natural light is incident from the natural light incident surface at night, the leakage of artificial light can be suppressed by covering the reflector here.

DESCRIPTION OF SYMBOLS 1 Building 1a Roof 2 Daylighting part 3 Duct 4 Ceiling 10 Illumination device 11 LED light source 11a Light emission part 11b Board | substrate 12 Light guide plate 12a 2nd main surface 12b 1st main surface 12c Side surface 12c 'Slope 12d Natural light incident surface 13 1st diffuser plate 14 Second diffuser plate 15 Reflecting member 16 Frame 17 Reflecting plate

Claims (18)

A second main surface including a natural light incident surface on which light emitted from a natural light source is incident; a first main surface facing the second main surface; an artificial light incident surface on which light emitted from the artificial light source is incident; A lighting device having a light guide plate having the artificial light source,
The second main surface is provided with an optical path deflecting unit that causes scattering when artificial light guided through the light guide plate is incident on a region other than the natural light incident surface, and the natural light incident surface includes: The optical path deflecting means is not provided,
The light emitted from the natural light source is incident from the natural light incident surface, passes through the light guide plate, and is emitted from the first main surface.
The light emitted from the artificial light source is incident from the artificial light incident surface, guided through the light guide plate, and then emitted from the first main surface via the optical path deflecting means. A lighting device.   The illumination device according to claim 1, wherein the optical path deflecting unit is configured by applying a diffusing agent containing diffusing particles to the second main surface.   The lighting device according to claim 1, wherein the optical path deflecting unit is configured by attaching a sheet containing diffusing particles to the second main surface.   The lighting device according to claim 2, wherein the density of the diffusing particles increases with distance from the artificial light source.   The lighting device according to claim 1, wherein the optical path deflecting unit is configured by forming a plurality of concave portions on the second main surface by machining.   The lighting device according to claim 5, wherein the pitch of the recesses decreases as the distance from the artificial light source increases.   The illumination device according to claim 5 or 6, wherein the depth of the concave portion increases with distance from the artificial light source.   The lighting device according to claim 1, wherein a reflection member is provided in an area where the optical path deflecting unit is provided on the second main surface.   The artificial light incident surface is a side surface of the light guide plate, and a reflective member is provided on a side surface facing the side surface of the light guide plate close to the artificial light source. The lighting device described in 1.   9. The artificial light incident surface is a side surface of the light guide plate, and the artificial light source is disposed to face both side surfaces with the light guide plate interposed therebetween. The lighting device described.   The lighting device according to claim 9 or 10, wherein the artificial light incident surface has a V-shaped groove shape.   The lighting device according to claim 1, wherein the artificial light incident surface is a part of the first main surface.   The lighting device according to any one of claims 1 to 12, wherein a first diffusion plate is provided facing the natural light incident surface.   The second diffusion plate is provided opposite to the first main surface, and the haze value of the first diffusion plate is larger than the haze value of the second diffusion plate. The lighting device described.   The lighting device according to claim 1, wherein the artificial light source has a plurality of different emission colors.   The illumination device according to claim 1, wherein an ultraviolet cut filter is provided on the natural light incident surface. The following formula is established, where A (mm) is the maximum dimension of the natural light incident surface and B (mm) is the maximum dimension of the second main surface. Lighting device.
0.5 <A / B <0.7 (1)   The lighting device according to claim 1, a sensor that detects the intensity of the natural light, and a control device that performs dimming / toning control of the artificial light source according to a signal from the sensor. Characteristic lighting mechanism.