JP2011071093A - Lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting fixture having a structure which can control light distribution characteristics while suppressing glare and whole luminous flux deterioration, and can change irradiation range simply only by exchanging a diffusion sheet. <P>SOLUTION: The lighting fixture is provided with a reflecting plate 1 having a concave portion 1a, a light source 2 arranged at the bottom part of the concave portion 1a of the reflecting plate 1, and a diffusion sheet 3 which is arranged at the light emitting region of the reflecting plate 1 and has a concavo-convex structure 3a formed on the surface. The diffusion sheet 3 has an incident surface to receive incident light from the light source 2 and a light outgoing surface to emit light from the light source 2, and has a portion in which the region of the incident surface where the intensity of incident light from the light source becomes maximum overlaps with the region of the diffusion sheet 3 where the diffusion angle becomes maximum. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a luminaire, and more particularly to a luminaire using a light emitting diode (LED).

  In recent years, reduction of the emission of carbon dioxide, a greenhouse gas, has been demanded from the viewpoint of preventing global warming, and accordingly, lighting fixtures having LED light sources and fluorescent light sources effective for power saving are increasing. . For example, lighting fixtures such as downlights and spotlights, which are often used as partial lighting, often use incandescent bulbs or mini-krypton bulbs as light sources, but these light sources have low luminous efficiency and are more efficient and energy saving. The shift to LED light sources and fluorescent light sources that can be made into electric power is progressing. In particular, LED light sources have a long lifespan and can reduce waste, can contribute to environmental conservation without containing harmful substances such as mercury, and in recent years there has been a marked improvement in luminous efficiency. The spread of lighting fixtures is rapidly progressing.

  In general, downlights and spotlights have light distribution characteristics such as the material and shape of the reflector, a light-shielding plate called a baffle, a lens, or a milky white diffuse cover in order to effectively use the light emitted from the light source. It is controlled and designed to obtain a desired light distribution characteristic according to the purpose of use. Lighting fixture manufacturers design optical members and manufacture and sell downlights and spotlights with various light distribution characteristics.

  As a lighting fixture using an LED light source, an example in which a bullet-type LED in which a lens is incorporated in an LED and a diffusion plate are used in combination is disclosed (Patent Document 1). However, in order to control light distribution characteristics using a bullet-type LED, it is necessary to change the light source used, and the light distribution characteristics cannot be easily controlled.

  On the other hand, an example in which two prism plates are used for a planar light source and the prism plate is rotated to enable easy light distribution control is disclosed (Patent Document 2). However, this method is intended for light distribution control by the light condensing effect of the prism, and the light emitted from a point light source with strong directivity such as an LED cannot be sufficiently diffused.

  Moreover, the lighting fixture which is provided with the LED light source and the light distribution control lens, and can perform light distribution control easily by making the light distribution control lens movable is disclosed (Patent Document 3). Moreover, the example which controls light distribution by arrange | positioning the illumination cover in which the Fresnel lens was shaped on the LED light source is disclosed (patent document 4). In either configuration, light distribution is controlled by the light collection effect of the lens. For this reason, there is a problem that the transmittance is reduced by total reflection due to the lens on the exit surface, and the total luminous flux of the light source is accordingly reduced. Further, because of the light distribution control by the lens, it is not possible to suppress glare when the lens unit is viewed directly.

  Furthermore, an example of an illuminating diffuser with irregularities formed by laser processing is disclosed (Patent Document 5). Here, a technique for controlling light distribution characteristics by combining various uneven structures on the surface of a diffusion plate is shown. However, the specific combination method of the concavo-convex structure is not described, and the combination with the reflecting plate is not described, so that the total luminous flux may be reduced depending on the directivity of the light source used.

JP 2000-188002 A JP 2009-54322 A JP 2004-199891 A JP 2005-317557 A JP 2000-48613 A

  In addition to the above technique, as a conventional light distribution control and glare suppression technique, there is a method of arranging a milky white diffusion plate on the light exit surface of the lighting fixture. Although this method has an effect of suppressing glare and diffusing light, there is a problem in that the total luminous flux is greatly reduced. That is, the light distribution characteristics cannot be easily controlled in various forms, and the light use efficiency is lowered, which is not preferable from the viewpoint of energy saving. Moreover, in order to change the irradiation range of the lighting fixture once installed, it was necessary to prepare the lighting fixture which shows a different light distribution characteristic, and to replace the lighting fixture main body.

  The present invention has been made in view of such points, and it is possible to control a light distribution characteristic while suppressing a decrease in glare and total luminous flux, and to provide a lighting apparatus having a structure that can easily change an irradiation range only by replacing a diffusion sheet. The purpose is to provide.

  As a result of intensive studies in order to solve the above problems, the inventor of the present invention, in a lighting fixture including a reflector having a concave portion and a light source disposed at the bottom thereof, has a predetermined light emitting area of the reflector. It has been found that the above object can be achieved by arranging a diffusion sheet having a diffusion angle, and the present invention has been completed based on this finding.

  The luminaire of the present invention includes a reflector having a concave portion, a light source disposed at the bottom of the concave portion of the reflector, and a diffusion having a concavo-convex structure formed on a light output region of the reflector. The diffusion sheet has a light incident surface that receives light from the light source, and a light output surface that emits light from the light source, and an incident light intensity from the light source on the light incident surface is The maximum region has a portion that overlaps a region where the diffusion angle is maximum in the diffusion sheet.

  The lighting fixture of the present invention covers a plurality of reflecting plates having concave portions, individual light sources respectively disposed at the bottoms of the concave portions of the plurality of reflecting plates, and covering each light output region of the plurality of reflecting plates. And a diffusion sheet having a concavo-convex structure formed on a surface thereof, wherein the diffusion sheet is a light incident surface that receives light from the plurality of light sources, and light output that emits light from the plurality of light sources. A portion having a surface where the intensity of incident light from each light source on the light incident surface is maximum overlaps a region where the diffusion angle provided for each light source is maximum in the diffusion sheet. It is characterized by having.

  The luminaire of the present invention includes a reflector having a concave portion, a light source disposed at the bottom of the concave portion of the reflector, and a diffusion having a concavo-convex structure formed on a light output region of the reflector. The diffusion sheet has a light incident surface that receives light from the light source and a light output surface that emits light from the light source, and a region directly above the light source is in the diffusion sheet. It has the part which overlaps with the area | region where a diffusion angle becomes the largest.

  The lighting fixture of the present invention covers a plurality of reflecting plates having concave portions, individual light sources respectively disposed at the bottoms of the concave portions of the plurality of reflecting plates, and covering each light output region of the plurality of reflecting plates. And a diffusion sheet having a concavo-convex structure formed on a surface thereof, wherein the diffusion sheet is a light incident surface that receives light from the plurality of light sources, and light output that emits light from the plurality of light sources. It has a surface, and a region immediately above each individual light source has a portion that overlaps with a region where the diffusion angle provided for each individual light source in the diffusion sheet is maximized.

  In the lighting fixture of the present invention, it is preferable that a diffusion angle in a region where the uneven structure of the diffusion sheet is formed is in a range of 0.1 to 80 degrees.

  In the lighting fixture of the present invention, it is preferable that the diffusion angle of the diffusion sheet becomes smaller as the distance from the region where the intensity of light incident from the light source becomes maximum becomes longer.

  In the lighting fixture of this invention, it is preferable to provide the said several light source, and to change the said diffusion angle of the said diffusion sheet to the concentric form centering on the said light source directly in the center.

  In the lighting fixture of the present invention, comprising a plurality of the light sources, the diffusion angle of the diffusion sheet, the center line is a straight line passing through the approximate center of the light exit surface of the entire lighting fixture and substantially directly above each light source, It is preferable to change according to the distance from each center line.

  In the luminaire of the present invention, comprising a plurality of the light sources, the diffusion angle of the diffusion sheet is a major axis direction that passes through the approximate center of the light exit surface of the entire luminaire and approximately right above each light source, It is preferable that the light source changes in a concentric ellipse shape substantially centered on each light source.

  The lighting fixture of the present invention includes a plurality of the light sources, and the diffusion angle of the diffusion sheet is an abbreviation of each light source in a circle that passes substantially right above each light source with the light exit surface of the entire lighting fixture as a center. It is preferable that the tangent line directly above is a center line, and changes according to the distance from each center line.

  In the lighting fixture of the present invention, comprising a plurality of the light sources, the diffusion angle of the diffusion sheet, the direction passing through the approximate center of the light exit surface of the entire lighting fixture and substantially directly above each light source, the short axis direction, It is preferable that the light source changes in a concentric ellipse shape with the center directly above each light source.

  In the lighting fixture of this invention, it is preferable that the said diffusion sheet has an area | region whose haze value is 10% or less in the light emission area | region ahead of the said reflecting plate.

  In the lighting fixture of the present invention, the light source includes a plurality of the light sources, and the diffusion sheet has an uneven structure corresponding to the arrangement of the light sources, and the unevenness differs by rotating and / or sliding the diffusion sheet. It is preferable that the structure formation region corresponds to each light source and the light distribution characteristics can be switched.

  In the lighting fixture of this invention, it is preferable that the said light source is a light emitting diode.

  According to the present invention, an object of the present invention is to provide a luminaire having a structure capable of controlling the light distribution characteristics while suppressing the glare and the reduction of the total luminous flux and easily changing the irradiation range only by replacing the diffusion sheet.

It is a figure which shows the relationship between the transmitted light intensity and the diffusion angle in the light transmissive panel which concerns on embodiment of this invention. It is a schematic diagram which shows the definition of the diffusion angle in the diffusion sheet used for the lighting fixture which concerns on embodiment of this invention. It is the schematic which shows an example of the cross-section of the lighting fixture which concerns on embodiment of this invention. (A)-(e) is a perspective view which shows an example of the lighting fixture which concerns on embodiment of this invention. (A), (b) is a perspective view which shows another example of the lighting fixture which concerns on embodiment of this invention. (A)-(f) is a plane schematic diagram of the diffusion sheet used when the light source is arrange | positioned circularly in the lighting fixture which concerns on embodiment of this invention, (g)-(k) is illumination. It is a plane schematic diagram of the diffusion sheet used when a light source is arrange | positioned linearly in an instrument. It is the photograph which looked directly at the light emission surface at the time of lighting of the lighting fixture which concerns on embodiment of this invention. (A), (b) is a figure which shows distribution with respect to the position directly above a light source of the diffusion angle in the diffusion sheet used for the lighting fixture which concerns on embodiment of this invention. (A)-(e) is a figure which shows distribution with respect to the position directly above a light source of the diffusion angle in the diffusion sheet used for the lighting fixture which concerns on embodiment of this invention. It is a cross-sectional schematic diagram which shows the uneven structure of the diffusion sheet surface used for the lighting fixture which concerns on embodiment of this invention. (A) is the plane schematic which shows an example of the diffusion sheet used when the light source is arrange | positioned circularly in the lighting fixture which concerns on embodiment of this invention, (b) is a linear light source in a lighting fixture. It is a plane schematic diagram which shows the diffusion sheet used when arrange | positioning in the shape. (A), (b) is the plane schematic which shows an example of the diffusion sheet used when the light source is arrange | positioned circularly in the lighting fixture which concerns on embodiment of this invention, (c), (d) These are the plane schematic diagrams which show an example of the diffusion sheet used when a light source is arrange | positioned linearly in a lighting fixture. (A) is a plane schematic diagram which shows an example of the diffusion sheet used when the light source is arrange | positioned in circular shape in the lighting fixture which concerns on embodiment of this invention, (b) is a linear light source in a lighting fixture. It is a plane schematic diagram showing an example of a diffusion sheet used when arranged in a shape. (A), (b) is a plane schematic diagram which shows another example of the diffusion sheet used when the light source is arrange | positioned circularly in the lighting fixture which concerns on embodiment of this invention, (c), ( d) is a schematic plan view showing another example of a diffusion sheet used when light sources are linearly arranged in a lighting fixture. (A) is a plane schematic diagram which shows another example of the diffusion sheet used when the light source is arrange | positioned in circular shape in the lighting fixture which concerns on embodiment of this invention, (b) is a light source in a lighting fixture. It is a plane schematic diagram which shows another example of the diffusion sheet used when arrange | positioning linearly. (A), (b) is a plane schematic diagram which shows the diffusion sheet which has a transparent part used for the lighting fixture which concerns on embodiment of this invention. (A)-(i) is a plane schematic diagram which shows an example of the diffusion sheet which has a transparent part used for the lighting fixture which concerns on embodiment of this invention. (A), (b) is the plane schematic diagram of the diffusion sheet which has a different uneven | corrugated structure used when the light source is arrange | positioned in circular shape in the lighting fixture which concerns on embodiment of this invention, (c), ( d) is a schematic plan view of a diffusion sheet having different concavo-convex structures used when light sources are arranged linearly in a lighting fixture. (A), (b) is the figure which showed the measurement position of the brightness | luminance in the light emission surface ahead of the reflecting plate in the lighting fixture which concerns on the Example of this invention. (A), (b) is a plane schematic diagram of the diffusion sheet used for the lighting fixture which concerns on the Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
A luminaire according to the present invention includes a reflector having a concave portion, a light source disposed at the bottom of the concave portion of the reflector, a light incident surface on which a concavo-convex structure is formed, and receives light from the light source, And a diffusion sheet having a light exit surface that emits light from the light source. In this configuration, it is preferable to dispose the uneven structure of the diffusion sheet on the light incident surface side of the light from the light source in consideration of diffusing the light from the light source and suppressing the decrease in the total light transmittance. In addition, in the lighting fixture which concerns on this invention, in order to suppress glare and to obtain a desired light distribution characteristic, an uneven | corrugated structure can be provided in the light emission surface in the range which does not produce a total luminous flux fall and a condensing effect.

  Further, in the lighting apparatus according to the present invention, the diffusion sheet is disposed in the light output region of the reflector, and the region where the incident light intensity from the light source on the light incident surface is maximum is the region where the diffusion angle is maximum on the diffusion sheet. And has an overlapping part. By making the diffusion angle of the diffusion sheet maximum in the region where the intensity of incident light from the light source is maximum, it is possible to effectively suppress glare when the luminaire is directly viewed.

  Next, the diffusion angle of the light transmissive panel will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing the relationship between the transmitted light intensity and the diffusion angle in the light transmissive panel according to the embodiment of the present invention, and FIG. 2 shows the light used in the illumination device according to the embodiment of the present invention. It is a schematic diagram which shows the definition of the diffusion angle in a permeable panel. As shown in FIGS. 1 and 2, incident light that has entered the light incident region of the light transmissive panel is diffused by the uneven portions of the light transmissive panel, and is emitted as transmitted light from the light exit surface side. For this reason, the transmitted light emitted from the light transmissive panel is attenuated in transmitted light intensity according to the angle with respect to the light output surface of the light transmissive panel.

  In the present invention, the “diffusion angle” means an angle (FWHM: Full Width Half Maximum) that is twice the angle (half-value angle) at which the transmitted light intensity is attenuated to half of the peak intensity. The diffusion angle is, for example, a goniophotometer (Nippon Denshoku Kogyo Co., Ltd., GC 5000L). The surface on which the uneven structure of the diffusion sheet is formed (uneven surface) is the incident surface, and is incident in the normal direction of the uneven surface. It can be obtained by measuring the angular distribution of transmitted light intensity with respect to the measured light. Here, the normal direction of the diffusion sheet indicates a direction perpendicular to the uneven surface of the diffusion sheet, as shown in FIG. The region where the diffusion angle of the diffusion sheet is maximum is a range of about 2 mmφ, which is the minimum region that can be measured with the variable angle photometer or the like.

  Examples of the lighting fixture that can be used in the present invention include a downlight, a spotlight, a ceiling light, a light-up lighting fixture, a line lighting fixture, and the like. Examples thereof include downlights such as LEDD66003W-LS1, LEDD44003W-LS1, manufactured by Toshiba Lighting & Technology Corp., NNN21637 and NNN21638 manufactured by Matsushita Electric Works, and spotlights such as LEDS80000W-LS and LEDS-80002-LS manufactured by Toshiba Lighting & Technology Corp.

  Since the light distribution characteristics of these luminaires are controlled mainly by the reflectors that make up the luminaires, it is necessary to design the material and shape of the reflectors in order to obtain the desired light distribution characteristics. If the lighting fixture which has the structure where the diffusion sheet which concerns on this invention is replaceable is used, a light distribution characteristic can be changed, without replacing | exchanging a lighting fixture main body and a reflecting plate.

  In addition, when the light distribution characteristics of the luminaire are controlled by a reflector as in the prior art, there is a problem that the glare is very strong and uncomfortable because the light source or reflector is directly viewed from within the illumination area. . Although it is possible to suppress glare in these lighting fixtures by arranging a diffusion plate at a position where light emitted from the lighting fixture enters, the light distribution characteristics change by the diffusion plate, or the total luminous flux This is not preferable from the viewpoint of energy saving.

  In the luminaire according to the present invention, the diffusion sheet has a portion where the region immediately above the light source overlaps with the region where the diffusion angle is maximum in the diffusion sheet. The region immediately above the light source means a region including a vertical line connecting the light incident surface of the diffusion sheet and the light source. FIG. 3 is a schematic view showing an example of a cross-sectional structure of a lighting fixture according to the present invention. As shown in the figure, a lighting fixture according to the present invention includes an LED 2 as a light source, a reflector 1 that reflects light from the LED 2, and a diffusion sheet 3 that diffuses light reflected by the reflector 1. Composed. The reflection plate 1 has a concave portion 1a formed in a substantially parabolic shape in a cross-sectional view, and the LED 2 is disposed on the bottom portion 1b in the concave portion 1a. The bottom in this case means a region including a position where the inclination angle of the slope of the concave portion 1a is minimized. The diffusion sheet 3 is arranged facing the LED 2 so that the concavo-convex structure 3 a is formed on one main surface, and the main surface having the concavo-convex structure 3 a becomes a light incident surface from the LED 2. In this configuration, when a light beam enters the light incident surface of the diffusion sheet 3 substantially perpendicularly, the diffusion angle of the light emitted from the diffusion sheet 3 is maximized immediately above the light source. In addition, the uneven structure 3a may be formed on the opposite side of the light incident surface from the LED 2.

  FIG. 4A to FIG. 4E are perspective views showing an example of a lighting fixture according to the embodiment of the present invention. The shape of the concave portion 1a of the reflector 1 is hemispherical (FIG. 4 (a)), semi-ellipsoidal (FIG. 4 (b)), conical (FIG. 4 (c)), and polygonal pyramid (FIG. 4). (D)), a cylindrical shape (FIG. 4 (e)), or a mixed shape thereof. In particular, in order to deflect light from the light source to the front, the cross-sectional shape is preferably a curved surface, and the cross-sectional shape is more preferably a parabolic shape. In addition, in order to obtain a uniform illuminance on the irradiation surface by the lighting fixture, the edge shape of the reflector 1 is preferably circular or elliptical. As a material of the reflecting plate 1, a reflecting surface made of metal or metal vapor deposition, or a reflecting surface made of white resin or the like may be used. Moreover, in order to control the light distribution characteristic by the diffusion sheet 3, it is preferable to use a reflecting surface composed of a mirror surface having a regular reflectance of 90% or more. Further, a fine concavo-convex structure may be formed on the reflecting surface in order to enhance diffusibility. In addition to the above, various reflectors 1 can be used as long as they can reflect light. For example, a resin such as polyester or polycarbonate is foamed to form pores inside to form a sheet, a sheet formed by mixing two or more resins, and a resin layer having a different refractive index is laminated. A sheet or the like can be used.

  FIG. 5A and FIG. 5B are perspective views showing another example of the lighting fixture according to the present embodiment. As shown in FIGS. 5 (a) and 5 (b), the lighting apparatus according to the present embodiment has a plurality of combinations of the diffusion sheet 3, the LED 2, and the reflector 1 shown in the structure of FIG. Can also be used, and the arrangement of them can be arbitrarily designed. FIG. 5A shows an example in which six reflectors 1 having LEDs 2 are arranged on a circular diffusion sheet 3 in a circular shape. FIG. 5B shows an example in which six reflectors 1 having LEDs 2 are arranged linearly on a rectangular diffusion sheet 3.

  FIGS. 6A to 6K are schematic plan views of the diffusion sheet 3 used in the lighting apparatus according to the present embodiment. About the diffusion sheet 3 in the lighting fixture which concerns on this Embodiment, according to arrangement | positioning of the light source of a lighting fixture, the number, shape, size, etc. of the formation area of the uneven structure 3a are designed and used. FIGS. 6A to 6F show an example of the diffusion sheet 3 when the light sources are arranged in a circular shape. For example, when the light source is distributed in a circle centered on the light exit surface of the entire luminaire, if the front image of the peripheral edge of the concave portion of the reflector 1 is circular, uniform illumination is obtained on the irradiation surface. Therefore, the formation region of the concavo-convex structure 3a is circular (FIGS. 6A, 6B, and 6C), elliptical (FIGS. 6D and 6E), or a combination of circular and elliptical (FIG. 6). (F)) is preferable. In this case, in order to obtain a desired light distribution characteristic by the diffusion sheet 3, the number of light sources and the number of formation regions of the concavo-convex structure 3a may be different.

  Similarly, when the light sources are distributed linearly, the formation region of the concavo-convex structure 3a can be designed. FIGS. 6G to 6K are schematic plan views illustrating an example of the diffusion sheet 3 used when the light sources are arranged in a straight line. In this case, the formation region of the concavo-convex structure 3a is circular (FIG. 6 (g)), elliptical (FIGS. 6 (h), (i), (j)), or a combination of circular and elliptical (FIG. 6 (k) )). 6A to 6K show examples of the diffusion sheet 3 in the case where the number of LED light sources is 5 or 6, but the unevenness of the diffusion sheet 3 depends on the number and arrangement of the light sources. The area and arrangement of the formation region of the structure 3a can be arbitrarily designed.

  Thus, in the illuminating device according to the present embodiment, when the plurality of reflectors 1 and the LEDs 2 are configured in combination, the diffusion sheet 3 is disposed so as to cover each light output region of the plurality of reflectors 1, A region for forming the concavo-convex structure 3 a is provided for each LED 2. That is, it is configured to have a portion where the region where the incident light intensity of the light emitting region in each LED 2 is maximum and the region where the diffusion angle of the concavo-convex structure 3a provided for each LED 2 is maximum overlap. To do. Thereby, even when a plurality of reflectors 1 and LEDs 2 are used, the light distribution characteristic can be controlled while suppressing the glare and the reduction of the total luminous flux.

  The diffusion sheet 3 according to the present invention has a large number of uneven structures on the surface. The uneven structure is, for example, a structure in which a large number of protrusions are provided on the surface. The shape of the protrusions may be approximately conical, approximately spherical, approximately ellipsoidal, approximately lenticular lens, or approximately parabolic, and the protrusions may be regularly or irregularly arranged. It may be. Further, the protrusions may be connected by a continuous curved surface. Further, a pseudo random structure in which irregular irregularities are connected by a continuous curved surface can also be preferably used. The pseudo-random structure is preferably a fine three-dimensional structure formed using a speckle pattern by interference exposure.

  A three-dimensional structure formed using a speckle pattern by interference exposure is suitable for forming a fine concavo-convex structure 3a of 20 μm or less, which was difficult by machining. In particular, the method of forming irregularities using a speckle pattern by interference exposure is a manufacturing method suitable for changing the diffusion angle in the region within the surface of the diffusion sheet 3. Also, an isotropic shape such as a microlens and an anisotropic shape such as a lenticular lens can be easily formed.

  The shape of the concavo-convex structure 3a of the diffusion sheet 3 according to the present invention can be arbitrarily designed according to the width and shape of the target irradiation range of the lighting fixture. In a luminaire showing an isotropic light output pattern without the diffusion sheet 3, it is preferable that the concavo-convex structure 3a is isotropic in order to make the irradiation range circular or square, and the irradiation range is elliptical. Or in order to make it a rectangle, it is preferable to make the uneven structure 3a into an anisotropic shape. The pitch and height of the concavo-convex structure 3a are preferably less conspicuous by being less than the resolution of the human eye, that is, 20 μm or less, and in particular, a technique for controlling light distribution characteristics by changing the height and suppressing glare. Is more preferable. The uneven structure is preferably an irregular uneven structure formed by a continuous curved surface from the viewpoint of suppressing glare.

  The diffusion sheet 3 having the concavo-convex structure 3a on the surface and changing the diffusion angle in the region within the surface of the diffusion sheet 3 can be specifically manufactured as follows. First, a sub-master type in which a speckle pattern is formed so that the diffusion angle changes depending on the position by irradiating a photosensitive material or a photoresist with a laser beam through a lens or a mask in advance by interference exposure. By changing the distance and size between the members constituting the laser irradiation system and adjusting the size, shape and direction of the speckle pattern, the diffusion angle can be controlled and the concavo-convex structure 3a having different diffusion angles can be recorded.

  In general, the diffusion angle depends on the average size and shape of the speckle. If the speckle is small, the diffusion angle is large. The unit structure of the concavo-convex structure 3a is not limited to an isotropic one, and an anisotropic one can be formed, or a concavo-convex structure 3a in which both are combined can be formed. If the speckle is an oval in the horizontal direction, the shape of the angular distribution is an oval in the vertical direction. In this way, a sub-master type in which the diffusion angle changes depending on the position is manufactured. A metal is deposited on the sub-master mold by a method such as electroforming, and a speckle pattern is transferred to the metal to produce a master mold. A speckle pattern is transferred to the light extraction surface of the light-transmitting resin layer by forming the light-transmitting resin layer with ultraviolet rays using the master mold. A detailed manufacturing method of the diffusion sheet 3 in which the diffusion angle is changed depending on the position is disclosed in JP-T-2003-525472. The diffusion angle may be controlled by changing the pitch, height, and aspect ratio of the concavo-convex structure 3a.

  In the luminaire according to the present invention, the diffusion angle in the formation region of the uneven structure 3a of the diffusion sheet 3 is preferably in the range of 0.1 degrees to 80 degrees. In particular, in order to suppress the decrease in the total luminous flux while controlling the light distribution characteristics, the diffusion angle immediately above the light source is preferably in the range of 10 degrees to 80 degrees, and more preferably in the range of 20 degrees to 70 degrees. preferable.

  In the luminaire according to the present invention, it is preferable that the diffusion angle of the diffusion sheet 3 becomes smaller as the distance from the region where the intensity of light incident from the light source becomes maximum becomes longer. Since the luminance at each part of the lighting fixture has a distribution, it is effective to use the diffusion sheet 3 having a different diffusion angle depending on the position in order to obtain a desired light distribution characteristic as a whole lighting fixture. Therefore, it is possible to control the light distribution characteristics while suppressing the decrease of the total luminous flux by increasing the diffusion angle in the region with high brightness on the light exit surface and decreasing the diffusion angle as the distance from the region becomes longer. It becomes.

  FIG. 7 is a photograph obtained by directly viewing the light exit surface when the lighting apparatus according to the present embodiment is turned on. In FIG. 7, the photograph which looked directly at the concave shaped reflecting plate 1 and the LED light source arrange | positioned at the bottom part is shown. Here, after emitting from the light source, the light is emitted from the front of the luminaire by being reflected from the concave reflector 1 in addition to the region A1 where the luminance is increased in a circular shape by the light emitted directly from the light source to the front of the luminaire. There is a region A2 where the brightness increases in a ring shape by light. In such a case, in the diffusion sheet, the diffusion angle is reduced in proportion to the distance from the region where the intensity of light incident from the light source is maximized, and further corresponds to the region A2 where the brightness increases in a ring shape. It is possible to suppress the glare by adjusting the diffusion angle.

  The diffusion angle in the present invention is expressed as shown in FIGS. 8A and 8B in the formation region of the concavo-convex structure 3 a on the diffusion sheet 3. For example, as shown in FIG. 8A, when the formation region of the concavo-convex structure 3a on the diffusion sheet 3 is circular, the diffusion angle is measured in the diameter direction with the position directly above the light source as the center. Similarly, when the formation region of the concavo-convex structure 3a is elliptical as shown in FIG. 8B, the diffusion angles are measured in the major axis direction a and the minor axis direction b of the ellipse with the position directly above the light source as the center.

  Fig.9 (a)-FIG.9 (e) are figures which show distribution with respect to the position directly above the light source of the diffusion angle of the diffusion sheet 3 used for the lighting fixture which concerns on this invention. The diffusion angle changes linearly with respect to the distance from the light source (FIGS. 9A and 9D), changes in a curve (FIGS. 9B and 9C), or It may be changed to a mixture of straight lines and curves (FIG. 9E). The distribution of the diffusion angle can be arbitrarily designed in order to obtain the luminance distribution of the luminaire and desired light distribution characteristics.

  The diffusion angle can be controlled by changing the pitch, height, and aspect ratio of the concavo-convex structure 3a. FIG. 10 is a schematic cross-sectional view showing the uneven structure on the surface of the diffusion sheet 3. When the distance from the end to the end of the cross section of the concavo-convex structure 3a is the pitch w, and the height of the convex portion at the pitch w is 1, the aspect ratio is expressed as 1 / w. The higher the aspect ratio, the higher the diffusion, and when the pitch is substantially constant, the higher the height of the convex portion, the higher the diffusion. In particular, in the formation of irregularities by the interference exposure method, the diffusion angle can be changed without recombining the optical system, so that the pitch is preferably substantially constant.

  Next, with reference to FIG. 11A and FIG. 11B, a plurality of light sources are arranged concentrically (FIG. 11A) or linearly (FIG. 11B), and the diffusion sheet 3 The case where the formation region of the concavo-convex structure 3a is circular will be described. In this case, it is preferable that the diffusion angle changes concentrically around each light source, the point being substantially immediately above the point where the light source is located 3b (hereinafter also simply referred to as the light source 3b). The edge shape of the reflector 1 may be a polygon such as a triangle, a quadrangle, or a hexagon, a circle, an ellipse, and the like. In particular, when the edge of the reflector is a circle or an ellipse, illumination is performed. Since the brightness of the light emitting surface of the appliance is distributed concentrically with the light source position directly above, effective light distribution characteristic control and glare suppression are possible.

  Next, with reference to FIGS. 12-15, the arrangement | positioning of the light source and diffusion sheet of the lighting fixture concerning this Embodiment, and the change of the diffusion angle in the formation area of the uneven structure 3a are demonstrated. First, referring to FIGS. 12A to 12D, a plurality of light sources are concentric (FIGS. 12A and 12B) or linear (FIGS. 12C and 12D). An example of the arrangement in d)) will be described. In this case, the diffusion angle of the diffusion sheet 3 is such that each center line L1 (radiation), which is a straight line passing through the approximate center point P1 (hereinafter also simply referred to as point P1) of the light exit surface of the entire lighting fixture, and each light source 3b, It is preferable that the distance from L2 is changed according to the distance in the direction D1 substantially perpendicular to the center lines L1 and L2 in the surface of the diffusion sheet 3. As shown in FIGS. 12A to 12D, the shape of the formation region of the concavo-convex structure 3a in each array is a circular shape and a rectangular shape in plan view. Also, the orthogonal direction D1 is substantially the same. The edge shape of the reflector may be a polygon such as a triangle, a quadrangle, or a hexagon, a circle, an ellipse, or the like.

  Next, a case where a plurality of light sources are arranged concentrically or linearly and the formation region of the concavo-convex structure 3a of the diffusion sheet 3 is elliptical will be described with reference to FIGS. To do. In this case, the diffusion angle of the diffusion sheet 3 is such that each of the center lines L1 (radiation) and L2 that are straight lines passing through the point P1 centered on the light exit surface of the entire lighting fixture and the light source 3b is the major axis direction, It is preferable to change according to the distance to the concentric elliptical direction D2 centering on the light source 3b. The edge shape of the reflecting plate may be a polygon such as a triangle, a quadrangle, or a hexagon, or a circle or an ellipse, and is particularly preferable when the shape of the edge of the reflector 1 is a circle or an ellipse. Applicable.

  Next, another example in which a plurality of light sources are arranged concentrically or linearly will be described with reference to FIGS. As shown in FIG. 14A and FIG. 14B, when a plurality of light sources are arranged concentrically, the diffusion angle of the diffusion sheet 3 is a point P1 centered on the light exit surface of the entire lighting fixture. A tangent line L3 directly above the light source of a circle passing directly above each light source 3b is used as a center line, and changes according to the distance from the center line (tangent line L3) to the tangent line L3 in the direction substantially perpendicular to the tangent line L3 in the plane of the diffusion sheet It is preferable. Further, as shown in FIGS. 14C and 14D, when a plurality of light sources are arranged in a straight line, the diffusion angle of the diffusion sheet 3 depends on the approximate center point P1 of the entire lighting fixture and each light source. It is preferable that the distance changes from the center line L2 which is a straight line passing through the top 3b in accordance with the distance from the center line L2 to the substantially parallel direction D4 within the surface of the diffusion sheet 3. As shown in FIGS. 14A to 14D, the shape of the formation region of the concavo-convex structure 3a in each array is either a circular shape or a rectangular shape in plan view. The direction D3 and the direction D4 are substantially the same direction. The edge shape of the reflecting plate may be a polygon such as a triangle, a quadrangle, or a hexagon, a circle, an ellipse, or the like.

  Next, with reference to FIG. 15A and FIG. 15B, a plurality of light sources are arranged concentrically or linearly, and the formation region of the uneven structure 3a of the diffusion sheet 3 is elliptical. Another example will be described. In this case, the diffusion angle of the diffusion sheet 3 is such that each center line L1 (radiation), which is a straight line passing through the point P1 centering on the light exit surface of the entire lighting fixture, and each light source 3b, and the center line L2 are short axis directions. It is preferable that the distance varies depending on the distance to the concentric elliptical direction D5 centering on the light source 3b. The edge shape of the reflecting plate 1 may be a polygon such as a triangle, a quadrangle, or a hexagon, a circle, an ellipse, and the like, and is particularly preferable when the shape of the edge of the reflector is a circle or an ellipse. Applicable.

  It is preferable that the diffusion sheet 3 has a region having a haze value of 10% or less in the light emission region A3 in front of the concave reflector 1. This region exists as a transparent portion that does not substantially diffuse light, and the haze value is more preferably 5% or less, and particularly preferably 3% or less. In addition, the said haze value can be measured on the conditions prescribed | regulated to JISK7136, for example.

  Next, the positional relationship between the concavo-convex structure 3a and the transparent portion 4 when the diffusion sheet 3 having a transparent portion is used will be described with reference to FIGS. 16 (a) and 16 (b). In the example shown in FIG. 16 (a), a circular diffusion sheet 3 having six concavo-convex structure 3a formation areas in the sheet surface is disposed on the light exit surface from the concave reflecting plate 1 having a circular edge shape. . In the surface of the circular diffusion sheet 3, there are six concentric circular light output areas A3. In the circular light-emitting area A3, an elliptical uneven structure 3a forming area is provided, and a small transparent portion 4 (substantially crescent shaped) is formed outside the elliptical uneven structure 3a in the short axis direction. ) Is formed.

  Similarly, in the example shown in FIG. 16 (b), a circular diffusion sheet having six concavo-convex structure 3a forming areas in the surface of the diffusion sheet 3 on the light exit surface from the concave reflecting plate 1 having a circular edge shape. 3 is arranged. In the surface of the circular diffusion sheet 3, there are six concentric circular light output areas A3. In the circular light emission region A3, a formation region of the circular concavo-convex structure 3a is provided, and a minute transparent portion 4 (annular) is formed outside the formation region of the circular concavo-convex structure 3a. Yes. As described above, the light output region A3 is divided into the formation region of the concavo-convex structure 3a that diffuses the light from the light source and the transparent portion 4 that transmits the light from the light source without diffusing it, thereby The beam angle can be controlled while suppressing the decrease.

  The transparent portion 4 that does not substantially diffuse light here means a region having a haze value of 10% or less, and if it falls within the above range, an antireflection treatment or the like is applied. Also good. The area of the transparent portion 4 is preferably 1% or more and 30% or less, and more preferably 1% or more and 20% or less of the area of the light output region A3 of each reflector from the viewpoint of 1/2 beam angle control. preferable. Further, from the viewpoint of glare suppression, it is preferably 1% or more and 30% or less, more preferably 1% or more and 10% or less, of the area of the light output region A3 of each reflector.

  FIG. 17A to FIG. 17I are schematic plan views illustrating an example of the diffusion sheet 3 having the transparent portion 4 in the light output region A3 in front of the reflection plate 1. The shape of the transparent portion 4 is determined by the shape of the formation region of the uneven structure 3 a on the diffusion sheet 3. For example, when the shape of the edge of the concave reflector is circular, if the formation region of the concavo-convex structure 3a is circular, the transparent portion 4 has a ring shape (FIG. 17A), and the formation region of the concavo-convex structure 3a is elliptical. If it takes the shape, the transparent part 4 becomes a crescent moon shape (FIGS. 17B and 17C). In addition, the formation area of the concavo-convex structure 3a is rectangular ((FIGS. 17 (d) and (e)), polygon (FIG. 17 (f)), and special shapes (FIGS. 17 (g) and (h)). By doing so, the shape of the transparent portion 4 can be designed.In addition, in FIG.17 (i), the edge shape of the reflecting plate is elliptical, and the formation region of the uneven structure 3a of the diffusion sheet 3 is circular. In this case, the shape of the transparent portion 4 is a crescent shape, and the example has been described above, but the shape of the transparent portion 4 is the target along with the distribution of the formation region of the concavo-convex structure 3a. It can be designed freely according to the degree of light distribution and glare elimination.

  In the luminaire according to the present invention, the light distribution characteristics can be switched corresponding to each light source by exchanging the diffusion sheet 3. The light distribution characteristics can be controlled by the material and shape of the reflecting plate 1. However, after the predetermined reflecting plate 1 is installed, additional design or replacement of the reflecting plate 1 takes time and cost. There was a problem that. Here, according to the lighting fixture which concerns on this invention, there exists the convenience that light distribution control is easily possible by replacement | exchange of the diffusion sheet 3. FIG.

  The diffusing sheet 3 in the lighting fixture according to the present invention has a concavo-convex structure corresponding to the position of each light source, and by rotating or sliding the diffusing sheet 3, a different concavo-convex structure forming region is associated with each light source, It is preferable that the light distribution characteristics can be switched. 18A and 18B are schematic plan views of the diffusion sheet 3 having different concavo-convex structures used when the light sources are arranged in a circular shape. As shown in FIGS. 18 (a) and 18 (b), in this case, the LED 2 can be applied to a lighting fixture in which six LEDs 2 are arranged in a circle, and by rotating the diffusion sheet 3, the LED 2 The formation region of the concavo-convex structure 3a located above can be switched between the concavo-convex structure 3a and the concavo-convex structure 3a ′ different from the concavo-convex structure 3a with respect to the rotation direction D6 of the diffusion sheet 3. FIGS. 18C and 18D are schematic plan views of diffusion sheets having different concavo-convex structures used when light sources are arranged linearly. In this case, it can be applied to a lighting fixture in which four LEDs 2 are arranged in a straight line. In this case, by sliding the diffusion sheet 3, the formation region of the uneven structure 3a located on the LED 2 is switched between the uneven structure 3a and the uneven structure 3a ′ with respect to the sliding direction D7 of the diffusion sheet 3. Can do. Note that the switching between the concavo-convex structure 3a and the concavo-convex structure 3a 'may be performed by combining rotation and sliding of the diffusion sheet 3.

  As a light source used for the lighting fixture which concerns on this invention, it is preferable that it is LED2. In the lighting fixture which concerns on this invention, a function is expressed by combining the diffusion sheet 3 on the irradiation side of a lighting fixture. In particular, in the lighting apparatus according to the present invention, when the diffusion sheet 3 is not used, an angle formed between a direction in which the light emitted from the lighting apparatus shows the maximum luminous intensity and a direction in which the luminous intensity is ½ of the maximum luminous intensity. Are preferably used with an angle twice (hereinafter referred to as 1/2 beam angle) of 0 to 70 degrees. As the light source, an incandescent bulb, a fluorescent lamp, or a mini-krypton sphere can be used, and it is more preferable to use an LED with higher directivity and higher luminance because the light distribution characteristics can be easily controlled. In particular, when the 1/2 beam angle is 50 degrees or less, the range of the incident angle of the light incident on the diffusion sheet 3 is narrow, and it becomes close to normal incidence, so that it is easy to control the transmitted diffused light. More preferably, it is more preferably 30 degrees or less.

  The diffusion sheet 3 used in the present invention can be used as a form in which a concavo-convex structure of an ultraviolet curable resin is transferred onto a base material sheet such as a polyester resin, triacetyl cellulose, polymethyl methacrylate, or polycarbonate. Moreover, you may use the diffusion sheet 3 as a form bonded together to the transparent resin plate or the glass plate via the adhesive or by thermal transfer. In particular, when used as a lighting fixture, a product produced by injection molding of polycarbonate or acrylic is preferable in order to give strength.

  In the diffusion sheet 3 used in the present invention, the concavo-convex structure 3a may be formed on both the light incident surface and the light exit surface, and has a variable angle prism shape on the opposite surface of the surface having the concavo-convex structure 3a. May be. By having the prism shape for angle change, the traveling direction of the irradiated light can be changed, and the desired irradiation direction can be illuminated effectively. For example, it is effective for illuminating a painting on the wall surface with a downlight attached to the ceiling, or as a wall washer application for illuminating the wall surface. Moreover, since it can illuminate the direction right below a lighting fixture when it attaches to an inclined ceiling like a staircase, when descent | falling a staircase, the glare by a light source entering a direct eye can be reduced.

  For the purpose of antireflection treatment, the diffusion sheet 3 used in the present invention may be provided with an antireflection coating on the surface opposite to the surface having the concavo-convex structure 3a, or may be shaped with a fine concavo-convex structure 3a. As a result, the total light transmittance can be improved, which leads to suppression of a decrease in the total luminous flux.

  If the lighting fixture which combined the diffusion sheet 3 which has the specific uneven | corrugated structure 3a which concerns on this invention is used, while being able to change a light distribution characteristic easily, an irradiation range can be changed easily only by replacement | exchange of the diffusion sheet 3. FIG. It has the convenience of.

  Next, examples carried out for clarifying the effects of the present invention will be described, but the present invention is not limited thereto.

[Downlight]
LED downlight manufactured by Toshiba Lighting & Technology, LEDD-66003W-LS1 was used. In this downlight, six sets of a reflector having a concave portion and LED light sources arranged at the bottom of the concave portion of the reflector are arranged as shown in FIG. 7, and a diffusion cover (frosted acrylic) is provided on the light exit surface side of the light source. Plate). In the diffusing cover, the intensity of incident light from the light source is maximized immediately above each LED light source, but is uniformly frosted in the plane.

[Diffusion sheet]
By controlling the speckle pattern, master molds having various uneven structures were produced. Next, using the master shape, an uneven structure made of an ultraviolet curable resin was formed on a polyester resin film having a thickness of 188 μm, and a diffusion sheet used for the lighting apparatus according to the present invention was produced.

[Various measurement methods]
(1) 1/2 beam angle An angle that is twice the angle formed by the maximum luminous intensity of the light emitted from the luminaire and the luminous intensity that is 1/2 the axial luminous intensity was defined as the 1/2 beam angle. The luminous intensity was obtained by converting an illuminance meter (manufactured by Hioki Denki Co., Ltd., Lux HiTester) at a horizontal distance of 1 m from the center position of the light emitting surface of the lighting device, and converting from the measured illuminance value.

(2) Measurement of total luminous flux The total luminous flux was measured by using two types of total luminous flux measurement systems (integrated hemisphere, integral total sphere). As the integrating hemisphere, a 1000 mmφ integrating hemisphere (manufactured by Otsuka Electronics Co., Ltd., Half Moon series) was used, and the lighting fixture was measured with the baffle inside the integrating hemisphere sandwiched and placed facing the receiving optical fiber. Further, as the integrating sphere, a 1000 mmφ integrating sphere (manufactured by Labsphere, CSLMS LED 4061) was used. The measured value of the total luminous flux was expressed as a relative value with the measured value of Comparative Example 3 described later as 100%.

(3) Luminance measurement The luminance on the light emitting surface of the lighting fixture was measured in a predetermined spot range by placing the light emitting surface of the lighting fixture and a luminance meter (LS-110, manufactured by Konica Minolta Sensing Co., Ltd.) at a distance of 1000 mm. FIGS. 19A and 19B are diagrams showing luminance measurement positions on the light exit surface in front of each reflector.

  As shown in FIG. 19A, when the formation region of the concavo-convex structure 3a is elliptical, the spot 5 positioned substantially at the center of the light output region A3 and the spot 5 on the long axis a of the formation region of the concavo-convex structure 3a The luminance at the three points of the adjacent spot 5a and the spot 5b adjacent to the spot 5 on the short axis b of the formation region of the concavo-convex structure 3a was measured. In addition, as shown in FIG. 19B, when the formation region of the concavo-convex structure 3a is circular, the spot 5 positioned substantially at the center of the light output region A3 and adjacent to the spot 5 on the radius of the formation region of the concavo-convex structure 3a. The brightness at two points of the spot 5 ′ to be measured was measured. The above results were used in determining glare.

(4) Determination of glare Based on the brightness value at each spot (5, 5a, 5b, 5 ′) measured by removing the lower surface cover (frosted acrylic plate) of the LED downlight (LEDD-66003W-LS1), The glare was evaluated based on the brightness decay degree D (see the following formula (1)).
Luminance attenuation D = [Luminance value at each spot (5, 5a, 5b, 5 ′) / Luminance value measured at each spot (5, 5a, 5b, 5 ′) with the lower surface cover removed] Formula (1)

The glare is divided into two regions immediately above the light source and around the edge of the reflector. The brightness attenuation D at the spot 5 is directly above the light source, and the average value of the brightness attenuation D at the spots 5a and 5b is around the edge of the reflector. Alternatively, the luminance attenuation degree D at the spot 5 ′ is used. Glare was determined according to the following criteria.
◎: D ≦ 0.2 Glare is hardly felt ○: 0.2 <D ≦ 0.6 Glare is not felt so much Δ: 0.6 <D ≦ 0.8 Some glare is felt ×: 0.8 ≦ D Strongly feel glare

(5) Comprehensive evaluation Comprehensive evaluation was performed according to the criteria shown in Table 1 below based on the above 1/2 beam angle, total luminous flux relative value, and glare determination results.

[Example 1]
As the diffusion sheet 3 of Example 1, a 188 μm thick polyester base material having an uneven structure made of an ultraviolet curable resin was used. FIG. 20A shows a schematic plan view of the diffusion sheet used in Example 1. FIG. In FIG. 20A, the linear direction connecting the LED light sources from the center of the diffusion sheet 3 in the 62 mmφ diffusion sheet 3 surface is defined as a major axis direction D8. As shown in FIG. 20A, the diffusion sheet 3 used in Example 1 has six formation regions of the elliptical concavo-convex structure 3a centering on the LED light source 3b. The formation region of each concavo-convex structure 3a has an elliptical shape having a major axis of 15 mmφ and a minor axis of 12 mmφ. In the diffusing sheet 3 of Example 1, in the light exit area A3 in front of the reflector, the transparent portion 6 that does not diffuse the light is present about 20% with respect to the entire light exit area A3 in front of the reflector.

  Moreover, the diffusion angle of the formation region of each concavo-convex structure 3a of the diffusion sheet 3 is distributed in a concentric ellipse shape centering on the light source 3b just above the LED light source. In the formation region of each concavo-convex structure 3a, the diffusion angle θ1 measured from the light source 3b immediately above the LED light source of the diffusion sheet 3 toward the long axis direction D8 has a maximum diffusion angle of 53 degrees and a minimum diffusion angle of 7 9 (b), the diffusion angle θ2 in the minor axis direction D9 is 53 ° for the maximum diffusion angle and 4 ° for the minimum diffusion angle, as shown in FIG. 9 (b). It was changing.

  Remove the bottom cover (frosted acrylic plate) of the LED downlight (Toshiba Lighting & Technology, LEDD-66003W-LS1), and arrange the concavo-convex structure forming surface of the diffusion sheet 3 to be the light incident surface of the light from the light source. And the lighting fixture of Example 1 was produced. After measuring the 1/2 beam angle and the total luminous flux, the luminance of the light exit surface was measured to calculate the luminance attenuation degree D, and the glare was determined. Table 2 below shows the 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the overall evaluation.

[Example 2]
The diffusion sheet 3 of Example 2 has the same area and arrangement of the formation region of the concavo-convex structure 3a as that of Example 1, and only the diffusion angle distribution is different. The diffusion angle of the diffusion sheet 3 is the minimum diffusion angle θ1 in the major axis direction D8 from the light source 3b directly above the LED light source of the diffusion sheet 3 in the formation region of each concavo-convex structure 3a. 9 (b), and the diffusion angle θ2 in the minor axis direction D9 has a maximum diffusion angle of 56 ° and a minimum diffusion angle of 2 °. It changed as shown in b).

  Remove the lower surface cover (frosted acrylic plate) of the LED downlight (Toshiba Lighting & Technology Corp., LEDD-66003W-LS1) so that the formation surface of the concavo-convex structure 3a of the diffusion sheet 3 becomes the light incident surface of the light from the light source The lighting fixture of Example 2 was produced. After measuring the 1/2 beam angle and the total luminous flux, the luminance of the light exit surface was measured to calculate the luminance attenuation degree D, and the glare was determined. The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

[Example 3]
As the diffusion sheet 3 of Example 3, the diffusion sheet 3 having the same area and arrangement of the concavo-convex structure 3a as that of Example 1 and different only in the distribution of the diffusion angle was used. The diffusion angle of the diffusion sheet 3 is 58 degrees at the maximum diffusion angle θ1 in the long axis direction D8 from the light source 3b directly above the LED light source of the diffusion sheet 3 in each unevenness forming portion (uneven structure 3a). The minimum diffusion angle is 9 degrees and changes as shown in FIG. 9B. The diffusion angle θ2 in the minor axis direction D9 is 58 degrees, and the minimum diffusion angle is 7 degrees. It changed as shown in 9 (b).

  Remove the lower surface cover (frosted acrylic plate) of the LED downlight (Toshiba Lighting & Technology Corp., LEDD-66003W-LS1) so that the formation surface of the concavo-convex structure 3a of the diffusion sheet 3 becomes the light incident surface of the light from the light source The lighting fixture of Example 3 was produced. After measuring the 1/2 beam angle and the total luminous flux, the luminance of the light exit surface was measured to calculate the luminance attenuation degree D, and the glare was determined. The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

[Example 4]
The diffusion sheet 3 of Example 4 was obtained by forming a concavo-convex structure with an ultraviolet curable resin on a polyester substrate having a thickness of 188 μm. FIG. 20B shows a schematic plan view of the diffusion sheet used in Example 4. As shown in FIG. 20B, the diffusion sheet 3 used in Example 4 has six formation regions of the concavo-convex structure 3a having a diameter R1 of 14 mmφ in the surface of the diffusion sheet 3 of 62 mmφ. In the light exit area A3 in front of the reflector, the diffusion sheet 3 of Example 4 has about 12% of the transparent portion 6 that does not substantially diffuse light with respect to the entire light exit area A3 in front of the reflector.

  In the formation region of each concavo-convex structure 3a shown in FIG. 20 (b), the diffusion angle from the position corresponding to 3b directly above the light source of the diffusion sheet 3 to the circumferential direction D10 changes as shown in FIG. 9 (c). The maximum diffusion angle was 55 degrees and the minimum diffusion angle was 18 degrees.

  Remove the bottom cover (frosted acrylic plate) of the LED downlight (Toshiba Lighting & Technology, LEDD-66003W-LS1), and arrange the concavo-convex structure forming surface of the diffusion sheet 3 to be the light incident surface of the light from the light source. And the lighting fixture of Example 4 was produced. After measuring the 1/2 beam angle and the total luminous flux, the luminance of the light exit surface was measured to calculate the luminance attenuation degree D, and the glare was determined. The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

[Example 5]
As the diffusion sheet 3 of Example 5, the diffusion sheet 3 equivalent to that of Example 4 was used except that the distribution of the diffusion angle was different in the formation region of each concavo-convex structure 3a. In the formation region of each concavo-convex structure 3a shown in FIG. 20 (b), the diffusion angle in the circumferential direction D10 from the position corresponding to the LED light source of the diffusion sheet 3 changes as shown in FIG. 9 (c). The maximum diffusion angle was 60 degrees and the minimum diffusion angle was 11 degrees.

  Remove the lower cover (frosted acrylic plate) of the LED downlight (Toshiba Lighting & Technology, LEDD-66003W-LS1), and place it so that the uneven surface of the diffusion sheet 3 becomes the light incident surface of the light source. The lighting fixture of Example 5 was produced. After measuring the 1/2 beam angle and the total luminous flux, the luminance of the light exit surface was measured to calculate the luminance attenuation degree D, and the glare was determined. The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

[Example 6]
The diffusion sheet 3 of Example 6 was the same as that of Example 4 except that the distribution of the diffusion angle was different in the formation region of each concavo-convex structure 3a. In the formation region of each concavo-convex structure 3a, the diffusion angle was uniformly 55 degrees. As described above, in the diffusion sheet 3 of Example 6, the value of the diffusion angle is uniform in the formation region of each concavo-convex structure 3a, and the transparent portion 6 that does not diffuse light around the entire light emission region A3 in front of the reflector. About 12% is present. That is, in Example 6, the diffusion sheet according to the present invention has two types of regions, the formation region of the uneven structure 3a having a diffusion angle of 55 degrees and the transparent portion 6, and the formation region of the uneven structure 3a is in the sheet plane. It can be regarded as a region showing the maximum diffusion angle. For this reason, the diffusion angle in the entire region of the formation region of each concavo-convex structure 3 a is maximized in the diffusion sheet 3.

  Remove the lower cover (frosted acrylic plate) of the LED downlight (Toshiba Lighting & Technology, LEDD-66003W-LS1) so that the concavo-convex structure 3a formation surface of the diffusion sheet 3 becomes the light incident surface of the light from the light source The lighting fixture of Example 6 was produced. After measuring the 1/2 beam angle and the total luminous flux, the luminance of the light exit surface was measured to calculate the luminance attenuation degree D, and the glare was determined. The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

[Comparative Example 1]
Example 1 except that the lower surface cover (frosted acrylic plate) of the LED downlight (LEDD-66003W-LS1) was changed to a diffusion sheet (made by Tsujiden Co., D123) whose surface was coated with resin beads. It was set as the same structure. The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

[Comparative Example 2]
The LED downlight (LEDD-66003W-LS1) has a lower surface cover (frosted acrylic plate), a diffusion plate (with a particle size of 2 μm, a true specific gravity of 1.35 silicone fine particles inside, containing 8,000 ppm in thickness, 1.2 mm) The configuration was the same as that of Example 1 except that the polystyrene plate was changed. The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

[Comparative Example 3]
The configuration was the same as Example 1 except that the lower surface cover (frosted acrylic plate) of the LED downlight (LEDD-66003W-LS1) was changed to a transparent acrylic plate (thickness 1.5 mm). The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

[Comparative Example 4]
After measuring 1/2 beam angle and total luminous flux of LED downlight (manufactured by Toshiba Lighting & Technology Corp., LEDD-66003W-LS1), the brightness of the light exit surface is measured to calculate the brightness attenuation D, and the glare is determined. It was. The 1/2 beam angle, the total luminous flux relative value, the glare determination result, and the comprehensive evaluation are shown in Table 2 below.

  From Table 2, compared with the case of using the transparent acrylic plate of Comparative Example 3, the total light flux reduction amount by the frosted acrylic plate was about 1%, but the glare by visual observation was seen as it was, It was uncomfortable (Comparative Example 4). Also, instead of the frosted acrylic plate, a diffusing plate or a commercially available diffusing sheet 3 is arranged to suppress glare and enlarge the 1/2 beam angle, but the total luminous flux is reduced by 10% or more. (Comparative Example 1 and Comparative Example 2).

  Here, the luminaire according to the present embodiment has an oval shape in the formation region of the concavo-convex structure 3a and has a transparent portion that does not diffuse light in the light exit surface area in front of the reflector, about 20% of the entire light exit surface. For the diffusion sheet 3 in which the diffusion angle is maximized and the diffusion angle is distributed in a concentric ellipse, the surface on which the concavo-convex structure 3a is formed is arranged as a light incident surface for light from the light source, thereby producing glare. In addition to the suppression, it was possible to expand the ½ beam angle without substantially reducing the total luminous flux (Examples 1 to 3).

  Moreover, the lighting fixture according to the present embodiment has a circular formation region of the concavo-convex structure 3a, and has a transparent portion that does not diffuse light in the light exit surface area in front of the reflector, about 12% of the entire light exit surface, and a diffusion angle directly above the light source. For the diffusion sheet 3 having a maximum distribution and concentrically distributed, the surface on which the concavo-convex structure 3a is formed is disposed as a light incident surface for light from the light source, thereby eliminating glare and reducing the total luminous flux. (Example 4 and Example 5) was able to expand the 1/2 beam angle.

  Furthermore, the luminaire according to the present embodiment has a circular region of the uneven structure 3a and has a transparent portion 6 that does not diffuse light in the light output surface area in front of the reflector, about 12% of the entire light output surface. For the diffusion sheet 3 having a uniform diffusion angle in the formation region, by disposing the surface on which the concavo-convex structure 3a is formed as the light incident surface from the light source, while eliminating the glare and suppressing the decrease in the total luminous flux, The 1/2 beam angle could be enlarged (Example 6).

  The present invention is not limited to the embodiment described above, and can be implemented with various modifications. For example, the material, arrangement, shape, and the like of the members in the above embodiment are illustrative, and can be implemented with appropriate changes. In addition, various modifications can be made without departing from the scope of the present invention.

  The lighting apparatus according to the present invention can control light distribution characteristics while suppressing glare and total light flux reduction, and further has a feature that the irradiation range can be easily changed only by replacing the diffusion sheet. It can be expected to be used in the lighting field, particularly in the lighting field having LED light sources.

DESCRIPTION OF SYMBOLS 1 Reflector 1a Concave part 1b Bottom part 2 LED (light source)
3 Diffusion sheet 3a Uneven structure 3b Directly above the light source 4, 6 Transparent part 5 Spot

Claims (14)

  A diffusion plate having a concave portion, a light source disposed at a bottom of the concave portion of the reflective plate, and a diffusion sheet disposed on a light output region of the reflective plate and having a concavo-convex structure formed on a surface thereof, The sheet has a light incident surface that receives light from the light source and a light output surface that emits light from the light source, and a region where the intensity of incident light from the light source on the light incident surface is maximized, A lighting apparatus having a portion overlapping with a region where the diffusion angle is maximum in the diffusion sheet.   A plurality of reflecting plates having concave portions, individual light sources respectively disposed at the bottoms of the concave portions of the plurality of reflecting plates, and arranged so as to cover each light output region of the plurality of reflecting plates, and uneven on the surface A diffusion sheet having a structure formed thereon, the diffusion sheet having a light incident surface for receiving light from the plurality of light sources and a light output surface for emitting light from the plurality of light sources, A region where the intensity of incident light from each light source on the light surface is maximized has a portion that overlaps a region where the diffusion angle provided for each light source is maximized on the diffusion sheet. lighting equipment.   A diffusion plate having a concave portion, a light source disposed at a bottom of the concave portion of the reflective plate, and a diffusion sheet disposed on a light output region of the reflective plate and having a concavo-convex structure formed on a surface thereof, The sheet has a light incident surface that receives light from the light source and a light output surface that emits light from the light source, and a region immediately above the light source has a maximum diffusion angle in the diffusion sheet. The lighting fixture characterized by having a part which overlaps.   A plurality of reflecting plates having concave portions, individual light sources respectively disposed at the bottoms of the concave portions of the plurality of reflecting plates, and arranged so as to cover each light output region of the plurality of reflecting plates, and uneven on the surface A diffusion sheet having a structure formed thereon, the diffusion sheet having a light incident surface that receives light from the plurality of light sources and a light output surface that emits light from the plurality of light sources, The lighting apparatus is characterized in that a region immediately above the light source has a portion overlapping with a region where the diffusion angle provided for each of the light sources is maximized in the diffusion sheet.   The luminaire according to any one of claims 1 to 4, wherein a diffusion angle in a region where the uneven structure of the diffusion sheet is formed is in a range of 0.1 to 80 degrees.   The illumination according to any one of claims 1 to 5, wherein the diffusion angle of the diffusion sheet decreases as the distance from the region where the intensity of light incident from the light source is maximum increases. Instruments.   The plurality of light sources are provided, and the diffusion angle of the diffusion sheet is changed concentrically with the light source directly above as a center. lighting equipment.   A plurality of the light sources are provided, and the diffusion angle of the diffusion sheet is a straight line passing through the approximate center of the light exit surface of the entire lighting fixture and substantially directly above each of the light sources, and depends on the distance from the center line. The lighting fixture according to claim 1, wherein the lighting fixture changes.   The light source includes a plurality of light sources, and the diffusion angle of the diffusion sheet has a major axis direction passing through the approximate center of the light exit surface of the entire luminaire and substantially immediately above each of the light sources, and approximately above each of the light sources. The lighting fixture according to any one of claims 1 to 6, wherein the lighting fixture changes into a concentric ellipse shape.   A plurality of the light sources, and the diffusion angle of the diffusion sheet is centered on a tangent line substantially above each light source of a circle passing substantially right above each light source with the light exit surface of the entire lighting fixture as the center, The lighting fixture according to any one of claims 1 to 6, wherein the lighting fixture changes according to a distance from each center line.   A plurality of the light sources, and the diffusion angle of the diffusion sheet is a short axis direction passing through the approximate center of the light exit surface of the entire luminaire and approximately right above each light source, and approximately above each light source. The lighting fixture according to any one of claims 1 to 6, wherein the lighting fixture changes into a concentric ellipse shape.   The lighting device according to any one of claims 1 to 11, wherein the diffusion sheet has a region having a haze value of 10% or less in a light emission region in front of the reflector.   A plurality of the light sources are provided, and the diffusing sheet has a concavo-convex structure corresponding to the arrangement of the light sources, and the diffusing sheet is rotated and / or slid to correspond different concavo-convex structure forming regions to the light sources. The lighting device according to any one of claims 1 to 12, wherein the light distribution characteristics can be switched.   The lighting apparatus according to claim 1, wherein the light source is a light emitting diode.