JP2012048975A - Indirect lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an indirect lighting system capable of reducing efficiency loss and moreover easily forming illumination environment according to an installation site.SOLUTION: The indirect lighting system comprises a wavelength converting sheet 1 which is fixed on a surface of a side exposed into an object space for illumination and converts an ultraviolet ray into a visible light and a light source unit 2 for emitting the ultraviolet ray toward the wavelength converting sheet 1. The wavelength converting sheet 1, in which a wavelength converting material for converting the ultraviolet ray into the visible light is carried on a base material 11 having translucency, has a light-diffusion property. The light source unit 2 comprises a package 21 having an ultraviolet LED, a lighting unit for lighting the ultraviolet LED, and a wiring board on which the package 21 is arranged. The wavelength converting sheet 1 is fitted on a wall face 3 or a ceiling face 4, and when the light source unit 2 irradiates the ultraviolet ray onto the wavelength converting sheet 1, the ultraviolet ray is wavelength-converted into the visible light and is reflected by the wall face 3 or the ceiling face 4, and thereby illumination light is obtained.

Description

  The present invention relates to an indirect illumination device using an LED as a light source.

  Conventionally, a light source is installed in a place where light emitted from a light source such as a fluorescent lamp does not reach the human eye directly, and indirect light that is irradiated and reflected toward the wall surface or ceiling surface is used as illumination light. Indirect lighting is known. Among indirect lighting, lighting in which a light source is incorporated into a ceiling or a wall and integrated with a building structure is also called architectural lighting. When using indirect lighting, compared to lighting that directly irradiates the floor with light from the lighting device (hereinafter referred to as “direct lighting”), it is easier to make the illuminance uniform, causing discomfort and difficulty in seeing objects. Reduce glare.

  However, since the fluorescent lamp has low directivity, even if light distribution control is performed, light is emitted from the light source in directions other than the wall surface and the ceiling surface. In addition, it is considered that a part of the light emitted toward the wall surface or ceiling surface is absorbed by the wall surface or ceiling surface without being reflected, and indirect lighting using a fluorescent lamp as a light source is compared to direct lighting. The floor illuminance is reduced to about 1/3 to 1/5. As a result, in order to obtain floor illumination equivalent to that of direct lighting using indirect lighting, the light output of the light source needs to be at least 2 to 3 times that of direct lighting, which increases power consumption and running. Cost burden increases.

  In recent years, LEDs have been used as a light source of an illumination device with the improvement in efficiency and price reduction of LEDs (light emitting diodes). LEDs have high directivity, and when used in an indirect lighting device, there is an advantage that light from a light source can be efficiently emitted toward a wall surface or a ceiling surface. In addition, it has a lifespan 3 to 4 times longer than that of a fluorescent lamp and has a long replacement cycle.

  As an indirect illumination device using an LED as a light source, for example, there is a configuration as shown in FIG. In FIG. 2, a light source device 2 including an ultraviolet LED that emits ultraviolet light is disposed in a light source storage box 24 whose one surface is open. The opening surface of the light source storage box 24 is covered with a wavelength conversion cover 10 including a phosphor that converts ultraviolet light emitted from the light source device 2 into visible light. Therefore, ultraviolet light (broken arrows in FIG. 2) emitted from the light source device 2 toward the wavelength conversion cover 10 is converted into visible light by the phosphor of the wavelength conversion cover 10 and is emitted from the wavelength conversion cover 10. (Solid arrow in FIG. 2). Indirect light obtained by reflecting light radiated from the wavelength conversion cover 10 to the outside of the light source storage box 24 by the ceiling surface 4 is used as illumination light.

  Moreover, the structure described in patent document 1 is also known as an illuminating device which used LED for the light source. In the configuration described in Patent Document 1, as shown in FIG. 3, an LED element 50 and a reflector 51 having a bowl-like cross section are provided in a box 5 having one open surface. The reflector 51 includes a phosphor 52 on the inner surface, and the opening surface of the box 5 is covered with a translucent body 53 having a characteristic that does not transmit ultraviolet rays. With this configuration, the wavelength of light emitted from the LED element 50 (broken line arrow in FIG. 3) is converted by the phosphor 52, then reflected by the reflector 51, and emitted from the opening surface of the box 5 (FIG. Solid line arrow in 3).

Japanese Patent Laying-Open No. 2001-243821 (page 4, FIG. 2)

  However, in the configuration shown in FIG. 2, since light is emitted from the wavelength conversion cover 10 in both the front and back directions, most of the light subjected to wavelength conversion in the wavelength conversion cover 10 is emitted into the light source storage box 24. Therefore, it is considered that a lot of light emitted from the wavelength conversion cover 10 does not go to the ceiling surface 4, and a part of the light going to the ceiling surface 4 is also absorbed by the ceiling surface 4. Thus, besides the energy loss due to the Stokes shift at the time of wavelength conversion, there is a loss that reduces the light output from the light source (hereinafter referred to as “efficiency loss”).

  The configuration described in Patent Document 1 is a surface-emitting light source using LEDs, and an LED element 50 and a phosphor 52 are housed in a box 5. In this surface-emitting light source, the positions of the LED element 50 and the phosphor 52 are fixed to constitute one light source as a whole, and it is difficult to form an illumination space according to the installation environment.

  This invention is made | formed in view of the said reason, and it aims at providing the indirect illumination apparatus which can form an illumination space according to an installation environment easily while reducing an efficiency loss.

  The indirect illumination device of the present invention includes a wavelength conversion sheet attached to a surface exposed to a space to be illuminated, and a light source device having an ultraviolet LED that emits ultraviolet light toward the wavelength conversion sheet. The wavelength conversion sheet is characterized in that a wavelength conversion material that converts ultraviolet light into visible light is carried on a light-transmitting substrate and has light diffusibility.

  In this indirect illumination device, the light source device preferably further includes a visible LED that emits visible light.

  In this indirect lighting device, it is more desirable that the wavelength conversion sheet is detachably attached to the surface with an adhesive material.

  In this indirect lighting device, it is more desirable that the wavelength conversion sheet is attached to a portion having a high reflectance with respect to visible light on the surface.

  In this indirect lighting device, the emission wavelength of the ultraviolet LED is more preferably 400 nm or less.

  According to the structure of this invention, there exists an advantage that it is easy to form an illumination space according to installation environment, reducing efficiency loss.

It is sectional drawing which shows this embodiment. It is sectional drawing which shows a conventional structure. It is sectional drawing which shows the other conventional structure.

(Embodiment 1)
In this embodiment, the wall surface 3 and the ceiling surface 4 are illustrated as a surface exposed to the space used as the object of illumination. Hereinafter, the vertical direction in FIG. 1 will be described as the vertical direction.

  The indirect lighting device according to the present embodiment is attached along each of the wall surface 3 and the ceiling surface 4 in a building, and converts the ultraviolet light into visible light (solid arrow in FIG. 1), and a wavelength conversion sheet. 1 and a light source device 2 that emits ultraviolet light (broken arrows in FIG. 1). The wavelength conversion sheet 1 does not necessarily need to be provided on both surfaces of the wall surface 3 and the ceiling surface 4, and may be provided on only one of them. Moreover, since the wavelength conversion sheet 1 and the light source device 2 are separated and the position where the wavelength conversion sheet 1 and the light source device 2 are attached can be determined independently of each other, an illumination space corresponding to the installation environment is formed. be able to.

  The wavelength conversion sheet 1 in this embodiment is attached along the wall surface 3 and the ceiling surface 4 as shown in FIG. In the wavelength conversion sheet 1, a wavelength conversion material (not shown) that converts ultraviolet light into visible light is carried on a light-transmitting substrate 11, and the wavelength conversion sheet 1 has light diffusibility. is doing. Specifically, the wavelength conversion sheet 1 is formed by laminating a wavelength conversion material on the surface of the base material 11 or mixing the wavelength conversion material into the base material 11. For the base material 11, for example, a material transparent to visible light and ultraviolet light is used.

  Moreover, light diffusibility can be provided to the wavelength conversion sheet 1 by using a material having particle properties as the wavelength conversion material. In the present embodiment, the wavelength conversion material uses three types of phosphors whose emission wavelengths are red, green, and blue wavelengths. Details of the three types of phosphors will be described later.

  As an example, the wavelength conversion sheet 1 of the present embodiment uses a rubber-like silicone resin having optical transparency as a base material 11 and is formed into a sheet shape having a thickness of about 300 μm and a length and width of about 1 m. In this embodiment, the rubber-like silicone resin used as the base material 11 is an example, and the type of the base material 11 is not limited, but is desirably a material having light transmittance and flexibility. By using a flexible material for the base material 11, it becomes possible to attach the wavelength conversion sheet 1 even on a curved surface such as a dome-shaped ceiling, for example, and the options for attaching the wavelength conversion sheet 1 are further increased.

  The light source device 2 includes a package 21 having an ultraviolet LED, a lighting device (not shown) for turning on the ultraviolet LED, and a wiring board (not shown) on which the package 21 is mounted. The light emission wavelength of the ultraviolet LED is preferably a UVA (315 nm to 400 nm) wavelength that has little influence on the human body, and an ultraviolet LED made of a gallium nitride (GaN) compound semiconductor that emits 350 nm to 400 nm ultraviolet light is used. desirable. Further, for example, ten packages 21 are arranged on the wiring board at intervals of about 5 cm.

  Each package 21 is provided with an optical member 22 such as a reflecting mirror or a lens for adjusting the light emission direction. Light distribution control is performed so that light from the light source device 2 is irradiated only on the wavelength conversion sheet 1 by installing the light source device 2 including an ultraviolet LED whose light emission direction is adjusted by the optical member 22 at an appropriate position. To do.

  In the present embodiment, the light source installation base 23 is attached to the wall surface 3, and the light source device 2 is installed on the upper surface of the light source installation base 23. Further, a light shielding piece 231 for preventing the ultraviolet light from the light source device 2 installed on the light source installation table 23 from going directly to the floor surface extends upward from the tip of the light source installation table 23. . As an example, in this embodiment, the light source installation base 23 is provided at a location about 30 cm below the ceiling surface 4.

  In the present embodiment, the three types of phosphors used as the wavelength conversion material have the mixing ratio adjusted so that the mixed color light of the light emitted by converting the ultraviolet light from the package 21 becomes white. The phosphor is preferably a material that does not absorb visible light of 400 nm or more. Thereby, the color of the wavelength conversion sheet 1 when the package 21 is turned off becomes white or nearly transparent, and the boundary between the wavelength conversion sheet 1, the wall surface 3, and the ceiling surface 4 is not conspicuous when the package 21 is turned off. Can be expected to decrease.

In this embodiment, Y ₂ O ₂ S: Eu as the red phosphor, (Ba, Mg) Al ₁₀ O ₁₇ : Eu, Mn as the green phosphor, and (Sr, Ca, Ba, Mg) as the blue phosphor. ) Each of the phosphors represented by ₁₀ (PO ₄ ) 6Cl ₂ : Eu was used. All of the phosphors are phosphors in which most of the absorption band is on the shorter wavelength side than the excitation wavelength of 400 nm and does not absorb visible light of 400 nm or more. Light diffusibility is imparted to the wavelength conversion sheet 1 by the phosphor particles. However, the phosphor used in the present embodiment is merely an example, and is not limited to the phosphor. In the present embodiment, an inorganic phosphor is used, but an organic phosphor may be used as long as it is a combination of phosphors that do not absorb visible light and the mixed color light becomes white. The organic phosphor is often soluble in a solvent, the granular feeling is reduced, the wavelength conversion sheet 1 can be made into a more uniform thin film, and the wavelength conversion sheet 1 becomes less noticeable.

  The ultraviolet light irradiated on the wavelength conversion sheet 1 is converted into white light by the wavelength conversion material. Since the intensity of the white light is proportional to the intensity of the ultraviolet light incident on the wavelength conversion sheet 1, a portion where the intensity of the ultraviolet light incident on the wavelength conversion sheet 1 is relatively strong is bright and the incident ultraviolet light. The part where the strength of is relatively weak becomes dark. Therefore, by controlling the light distribution in consideration of the intensity of the ultraviolet light applied to each part of the wavelength conversion sheet 1 of the light source device 2, the light intensity peculiar to indirect illumination is also reproduced in this embodiment. It is possible.

  The wavelength conversion sheet 1 may be in a form of being attached from a cloth pasted on the wall surface 3 or the ceiling surface 4 or may be a cloth itself stuck on the wall surface 3 or the ceiling surface 4. Moreover, in order to attach the wavelength conversion sheet | seat 1 to the wall surface 3 and the ceiling surface 4, an adhesive material (not shown) is used, for example. As the adhesive material, a material directly applied to the wavelength conversion sheet 1, a mode such as a double-sided tape, a member coated with an adhesive material on both surfaces, or the like can be used. This makes it possible to replace the wavelength conversion sheet 1 when brightness decreases due to contamination of the wavelength conversion sheet 1 or changes in light color due to deterioration over time, and the life of the indirect illumination device is improved.

  Moreover, it is desirable that the wall surface 3 and the ceiling surface 4 to which the wavelength conversion sheet 1 is attached are white, and the adhesive material to which the wavelength conversion sheet 1 is attached is also white. Efficiency loss can be further reduced by making the back surface of the wavelength conversion sheet 1 a white system with high reflectance.

(Embodiment 2)
In the present embodiment, in addition to the package 21, a package (not shown) having LEDs that emit orange light is arranged between the adjacent packages 21 of the light source device 2 one by one at equal intervals. The emission wavelength of the visible LED is, for example, 650 nm. The ultraviolet LED package 21 and the visible LED package are connected to different lighting circuits.

In addition to the three types of phosphors used in Embodiment 1, the base material 11 of the wavelength conversion sheet 1 carries a light diffusion material (not shown) in order to diffuse the light of the visible LED. In the present embodiment, silicon dioxide (SiO ₂ ) particles having an average particle diameter of about 10 μm are used as an example of the light diffusing material. The wavelength conversion sheet 1 uses the ultraviolet LED and the visible LED to realize light having the same chromaticity as that of the first embodiment. Adjust the output ratio. For example, in the first embodiment, the average color rendering index of illumination light is 84 at the maximum, but when the configuration of this embodiment is applied, the average color rendering index can be improved to 92.

  In this embodiment, the light color of the visible LED is selected to be orange, but is not particularly limited to orange. If the LED emits light in the visible wavelength region where the emission intensity of the phosphor is small, the color rendering property is achieved. Is likely to improve In the present embodiment, silicon dioxide is used as the light diffusing material, but it is not particularly limited to silicon dioxide. Further, depending on the type of wavelength conversion material, it is possible to diffuse light from the visible LED without using a light diffusing material. Alternatively, light can also be diffused by applying uneven processing to the surface of the wavelength conversion sheet 1.

  As another example of this embodiment, if a visible LED that emits light in the same wavelength region is used instead of the wavelength conversion material, the type and quantity of the wavelength conversion material can be reduced. Therefore, when the lifetime of the indirect illumination device is determined by a specific wavelength conversion material, the lifetime of the indirect illumination device can be improved by replacing the wavelength conversion material with a visible LED. Moreover, when the ratio of the material cost of a specific wavelength conversion material is large, cost reduction is attained by substituting the said wavelength conversion material for visible LED.

  Other configurations and effects are the same as those of the first embodiment. In the above-described embodiment, the surface exposed to the space to be illuminated is the wall surface 3 and the ceiling surface 4. However, as long as the surface is exposed to the space to be illuminated, it may be a floor surface or the surface of furniture. . Moreover, the light source device 2 should just be installed so that only the wavelength conversion sheet 1 may be irradiated, for example, the form accommodated in the instrument with a leg etc. may be sufficient.

DESCRIPTION OF SYMBOLS 1 Wavelength conversion sheet 11 Base material 2 Light source device 3 Wall surface 4 Ceiling surface

Claims (5)

  A wavelength conversion sheet attached to the surface of the surface exposed to the space to be illuminated, and a light source device having an ultraviolet LED that emits ultraviolet light toward the wavelength conversion sheet, the wavelength conversion sheet is An indirect illumination device characterized in that a wavelength conversion material that converts ultraviolet light into visible light is carried on a light-transmitting base material and has light diffusibility.   The indirect illumination device according to claim 1, wherein the light source device further includes a visible LED that emits visible light.   The indirect illumination device according to claim 1, wherein the wavelength conversion sheet is detachably attached to the surface with an adhesive material.   The indirect illumination device according to any one of claims 1 to 3, wherein the wavelength conversion sheet is attached to a portion having a high reflectance with respect to visible light on the surface. The indirect illumination device according to any one of claims 1 to 4, wherein an emission wavelength of the ultraviolet LED is 400 nm or less.

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