JP5619406B2 - Illumination body - Google Patents

Description

  The present invention suppresses interference of light emitted from light sources arranged in adjacent recesses in a light reflecting member, and can illuminate a desired portion of a light transmissive light diffusing sheet with a clear outline. For example, the present invention relates to an illuminating body that can be suitably used for an electrical decoration signboard, an internally illuminated sign, a backlight of a liquid crystal display device, an illumination device, and the like.

  Conventionally, fluorescent lamps and cold cathode fluorescent lamps (CCFLs) that have a relatively long light source lifetime have been used as light sources for electrical signs, interior-lit signs, liquid crystal display backlights, and lighting devices. It is used.

  However, fluorescent tube lamps are straight tube type and easy to break, and cold cathode fluorescent tubes use mercury that is used at high voltage, so there are problems in environmental pollution due to illegal dumping and safety to human body. Yes.

  Therefore, a light emitting diode (LED) that is easy for the environment, has a long life, and is excellent in energy saving is promising as a light source to replace a fluorescent tube lamp and a cold cathode fluorescent tube.

  Then, by using a point light source such as a light emitting diode, only the part corresponding to the light source can be illuminated, so only the necessary part is lit by controlling the turning on and off of each light source. Attempts have been made to promote energy saving and improve contrast by local dimming (for example, Patent Document 1).

  However, point light sources such as light emitting diodes emit light at a predetermined radiation angle, so even if only the light source corresponding to the part to be lit is lit, it corresponds to the light source adjacent to the lit light source. The light is incident on the part to be turned on, the outline of the part to be lit is blurred, or the part to be lit cannot be formed into a desired shape.

 Therefore, in Patent Document 2, by providing a partition wall around a range including at least one point light source, by preventing light from entering each other outside the range, the luminance of the lighting area and the non-lighting area is determined. A method for clearly dividing the distribution is disclosed.

 However, as described above, when the partition walls are randomly arranged, the luminance distribution between the lighting and extinguishing adjacent to each other can be clearly distinguished. However, when the light sources adjacent to each other are both lit, it is accompanied by the arrangement of the partition walls. There is a problem that uneven brightness occurs.

JP 2008-159450 A JP 2007-286627 A

  INDUSTRIAL APPLICABILITY The present invention can suppress interference of light emitted from light sources disposed in adjacent concave portions in a light reflecting member, and can illuminate a desired portion of a light transmissive light diffusing sheet with a clear outline. Provide an illuminator.

The illuminating body of the present invention has a plurality of concave portions formed by expanding a thermoplastic resin sheet having light reflectivity from the front surface to the rear surface by thermoforming, and the inner bottom surface of the concave portion is provided with a light source. And a light reflecting member formed on a light reflecting surface for reflecting light emitted from the light source, and a front side of the light reflecting member. A light-transmitting light diffusing sheet disposed in contact with the light reflecting member and the light source disposed in the light source disposing portion of the concave portion of the light reflecting member, The light emission angle of the light source is set to θ between the recesses adjacent to each other at a cut surface that passes through the light sources disposed in these recesses and is cut at a plane orthogonal to the light transmissive light diffusion sheet. And passing through the light source and the light transmissive light. A straight line P ₁ perpendicular to the diffuser sheet, the angle angle formed by the straight line P ₂ that minimizes the and the straight line P ₁ into contact with the light-reflecting surface of the concave portion with through said light source and alpha, further, Between the recesses adjacent to each other, a straight line P ₃ orthogonal to the light transmissive light diffusing sheet from a point where the straight lines P ₂ intersect each other passes through the point where the light transmissive light diffusing sheet intersects the light source. When the angle formed by the straight line P ₄ and the straight line P ₁ is β, the following expressions 1 and 2 are satisfied.
α = β Equation 1
α <θ Equation 2

In the above illuminating body, the light sources disposed in the recesses can be turned on and off independently of each other . In the illuminating body, the concave portions are connected to each other by a connection portion formed on a reflective surface having a flat front surface. Furthermore, in the illuminating body, the concave portion has a reverse truncated cone shape. In the above illuminating body, the concave portion has a reverse truncated pyramid shape.

  Since the illuminating body of the present invention has the above-described configuration, it is possible to substantially suppress interference of light emitted from the light sources disposed in the recesses adjacent to each other, and turn on the desired light source. Thus, a desired portion of the light transmissive light diffusing sheet can be illuminated with a clear outline.

And, since it is in the illuminating body alpha = beta, reliably suppressed from interfering before the light emitted from a light source disposed in a recess adjacent reaches the light transmissive light diffusion sheet By turning on a desired light source, a desired portion of the light transmissive light diffusing sheet can be lit with a clear outline, and the luminance distribution of the light transmissive light diffusing sheet can be further clearly divided. .

  Furthermore, even if the light emitted from the light sources arranged in the recesses adjacent to each other has a different color, the light emitted from each light source does not mix with each other. Accordingly, a desired portion of the light transmissive light diffusing sheet can be illuminated, and the desired portion of the light transmissive light diffusing sheet can be illuminated with a desired color with a clear outline.

  In the above illuminating body, when the concave portions are connected by a connecting portion formed on a flat reflective surface, the interval between the concave portions can be adjusted by adjusting the width of the connecting portion. Accordingly, the degree of freedom of design of the recess itself can be increased, and can be developed for various uses.

It is the vertical end view which showed the illuminating body of this invention. It is the perspective view which showed the light reflection member. It is the partial front view which showed the recessed part of the light reflection member. It is the end elevation which showed a part of illumination body. It is the end elevation which showed a part of illumination body. It is the end elevation which showed a part of illumination body. It is the schematic diagram which showed the measuring point of the light radiation angle of a light source. It is the partial front view which showed another example of the recessed part of the light reflection member. It is the perspective view which showed the recessed part of FIG. It is the partial front view which showed another example of the recessed part of the light reflection member. It is the perspective view which showed the recessed part of FIG. It is the partial front view which showed another example of the recessed part of the light reflection member. It is the perspective view which showed the recessed part of FIG. It is the end elevation which showed another example of the recessed part of a light reflection member. It is the partial front view which showed another example of the recessed part of the light reflection member. It is the perspective view which showed the recessed part of FIG. It is the partial front view which showed another example of the recessed part of the light reflection member. It is the perspective view which showed another example of the light reflection member. It is the perspective view which showed another example of the light reflection member. It is the end elevation which showed a part of illumination body. It is the end elevation which showed a part of illumination body. It is the photograph which showed the lighting image of the illumination body obtained by the Example and the comparative example.

  An example of the illumination body of the present invention will be described with reference to the drawings. The illuminating body L of the present invention includes a light reflecting member A, a light transmissive light diffusing sheet B disposed in front of the light reflecting member A, and light sources C, C and C disposed on the light reflecting member A. .. and have

  The light reflecting member A is formed by thermoforming the light reflecting thermoplastic resin sheet 1. As shown in FIG. 1, the light reflecting member A is swelled by thermoforming the planar rectangular thermoplastic resin sheet 1 from the front surface toward the rear surface in a portion excluding the outer periphery of the four sides. A number of the same inverted truncated quadrangular pyramid-shaped recesses 2, 2... Vertically and horizontally in a state where the opening edges of the recesses 2, 2... Are parallel to the long side or the short side of the thermoplastic resin sheet 1. It is formed at predetermined intervals in the direction via connecting portions 24 described later.

  Specifically, as shown in FIG. 3, the concave portion 2 has a flat bottom surface 21 with a flat top surface and a state in which the concave portion 2 gradually expands from the four-side outer periphery of the bottom surface portion 21 toward the front side. The peripheral wall portion 22 extends. In this peripheral wall portion 22, four inverted isosceles trapezoidal peripheral wall pieces 22a, 22a,... Share the opposite inclined sides over the entire length between the adjacent peripheral wall piece portions 22a, 22a. As a result, it is integrally formed in the circumferential direction of the bottom surface portion 21 and formed in a funnel shape, and the inner surface of the continuous portion 22b between the peripheral wall piece portions 22a and 22a is a smooth concave arc surface that is not cut or cracked over the entire length. The inner peripheral surface of the peripheral wall portion 22 is formed entirely on a light reflecting surface 22c that reflects light emitted from the light source C described later. Furthermore, the inner surface of the continuous portion between the peripheral wall portion 22 and the bottom surface portion 21 is also formed into a smooth concave arc surface, preferably a concave arc surface, that is completely free of cuts and cracks.

  The inner bottom surface of the concave portion 2, that is, the inner surface of the bottom surface portion 21, is a flat light source arrangement portion 23 for arranging a light source C such as a light emitting diode. The through hole 21a is provided between the front and rear surfaces, and the light source C can be arranged on the light source arrangement portion 23 through the through hole 21a.

  Further, the recesses 2, 2 adjacent to each other are integrated on the whole through the connection portions 24 formed in a lattice shape at the opening edges thereof. The front surface of the connection portion 24 is formed on a reflection surface 24a that is flat on the entire surface, and no irregularities are formed, and no cuts or cracks are formed. As shown in FIG. 4, the connecting portion 24 does not have to have a flat front surface, and may be formed in a convex arc shape in cross section with the front surface formed on the reflecting surface 24 a ′.

  Next, a method for manufacturing the light reflecting member A will be described. First, the light-reflective thermoplastic resin sheet used as the material of the light reflecting member A is not particularly limited as long as it can reflect light. In the thermoplastic resin sheet, inorganic materials such as titanium oxide and calcium carbonate are used. Light reflectivity can be imparted by incorporating a filler.

  If the total light reflectivity of the thermoplastic resin sheet having light reflectivity is low, the light reflectivity of the light reflecting member may be lowered, so 96% or more is preferable, and 98 to 100% is more preferable.

  Further, if the ratio of the diffuse reflectance in the total light reflectance of the thermoplastic resin sheet having light reflectivity is low, the reflectivity in all directions of the light reflecting member may be lowered, so 90% or more. Preferably, 95 to 100% is more preferable.

  In addition, the light ray total reflectance and diffuse reflectance of the thermoplastic resin sheet are light rays having a wavelength of 550 nm when total reflection light measurement is performed under an incident condition of 8 ° in accordance with measurement method B described in JIS K7105. The total reflectance and diffuse reflectance were measured in an environment of room temperature 20 ° C. and relative humidity 60%. When the barium sulfate plate was used as a standard reflector, the total light reflectance and diffuse reflectance were 100. The relative value was used.

  The thermoplastic resin is not particularly limited, and examples thereof include polyethylene resins, polyolefin resins such as polypropylene resins, polyester resins, acrylic resins such as polymethyl acrylate, polyvinyl chloride resins, and polychlorinated resins. Examples thereof include diene resins such as vinylidene resins, fluorine resins, polyether resins, polyamide resins, polyurethane resins, polybutadienes, polyolefin resins are preferable, and polypropylene resins are more preferable. In addition, a thermoplastic resin may be used independently or 2 or more types may be used together.

  Examples of the polyethylene resin include low density polyethylene, linear low density polyethylene, high density polyethylene, and medium density polyethylene.

  Examples of the polypropylene resin include homopolypropylene, ethylene-propylene copolymer, propylene-α-olefin copolymer, and the like, since the volatile component is not generated even when the light reflecting member is heated. preferable. Further, when the light reflecting member is formed by foaming, the polypropylene resin is preferably a high melt tension polypropylene resin disclosed in Japanese Patent No. 2521388 or Japanese Patent Application Laid-Open No. 2001-226510. .

  In addition, the ethylene-propylene copolymer and the propylene-α-olefin copolymer may be either a random copolymer or a block copolymer. The content of the α-olefin component in the propylene-α-olefin copolymer is preferably 0.5 to 30% by weight, and more preferably 1 to 10% by weight.

  Examples of the α-olefin include α-olefins having 4 to 10 carbon atoms, such as 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene and the like. Is mentioned.

  The titanium oxide includes a rutile type, anatase type and ilmenite type, but a rutile type is preferred. And if titanium oxide has strong photocatalytic action, it will degrade the thermoplastic resin and cause the light reflectivity of the light reflecting member to decrease, so it is preferable to perform surface treatment.

  Although it does not specifically limit as the surface treatment method of the said titanium oxide, The method etc. which coat | cover with hydrous oxides, such as aluminum, silicon, titanium, zirconium, tin, etc. are mentioned.

  And, if the content of titanium oxide in the thermoplastic resin composition is small, the light reflectivity of the light reflecting member is lowered, while at most, the light reflecting of the light reflecting member is commensurate with the blending amount of titanium oxide. In addition to the improvement in properties, the light reflecting member is also reduced in lightness, so that it is preferably 10 to 100 parts by weight, more preferably 20 to 80 parts by weight, more preferably 30 to 65 parts by weight based on 100 parts by weight of the thermoplastic resin. Part by weight is particularly preferred.

  The thermoplastic resin sheet having light reflectivity may be a foamed sheet or a non-foamed sheet. First, as a method for producing a thermoplastic resin foam sheet having light reflectivity, a general-purpose method is adopted. For example, a thermoplastic resin, an inorganic filler and a foaming agent, and, if necessary, an additive to an extruder. A method of producing a thermoplastic resin foam sheet by supplying and melt-kneading to obtain a foamable thermoplastic resin composition, and extruding and foaming the foamable thermoplastic resin composition from a die attached to the tip of an extruder. . The die is not particularly limited as long as it is widely used in extrusion foaming, and examples thereof include a T die and an annular die.

  In the above production method, when a T die is used as the die, a thermoplastic resin foam sheet can be produced by extrusion foaming into a sheet form from an extruder, while when an annular die is used as the die. The cylindrical body is extruded and foamed from a circular die to produce a cylindrical body, and the cylindrical body is gradually expanded in diameter and then supplied to a cooling mandrel to be cooled. A thermoplastic resin foam sheet can be produced by cutting the inner and outer peripheral surfaces, opening them, and developing them.

  The blowing agent is not particularly limited, and is an organic gas such as saturated aliphatic hydrocarbons such as propane, butane and pentane, and halogenated hydrocarbons such as tetrafluoroethane, chlorodifluoroethane and difluoroethane; carbon dioxide and nitrogen gas. Gaseous inorganic compounds such as water; liquid inorganic compounds such as water; mixtures of organic acids or salts thereof with bicarbonate, such as a mixture of sodium bicarbonate and citric acid, dinitrosopentamethylenetetramine, etc. Solid foaming agents and the like are mentioned, and it is preferable to use a mixture of an organic acid or a salt thereof and bicarbonate and an organic gas, and a mixture of sodium bicarbonate and citric acid and an organic gas are preferably used. It is more preferable to use together.

  Next, as a method for producing a non-foamed thermoplastic resin sheet having light reflectivity, a general-purpose method is employed. For example, the above-described thermoplastic resin, inorganic filler, and, if necessary, an extruder are used as an extruder. And a melt-kneaded composition to obtain a thermoplastic resin composition, and a method of producing a thermoplastic resin non-foamed sheet by extruding the thermoplastic resin composition into a sheet form from a T die attached to the tip of an extruder. .

  Furthermore, a thermoplastic resin foam sheet or a thermoplastic resin non-foamed sheet may be laminated and integrated on one surface of the thermoplastic resin sheet to form a laminated sheet. As a method for producing such a laminated sheet, a general-purpose method is employed. For example, (1) a thermoplastic resin foam sheet constituting a light reflecting member and a thermoplastic resin non-foamed sheet are laminated together by a coextrusion method. A method of integrating, (2) a method of laminating and integrating the thermoplastic resin non-foamed sheet constituting the light reflecting member and the thermoplastic resin foamed sheet by a co-extrusion method, and (3) heat constituting the light reflecting member. Examples include a method of extruding a thermoplastic resin non-foamed sheet on one surface of a thermoplastic resin foam sheet, and (4) a method of thermally laminating a thermoplastic resin non-foamed sheet on one surface of a thermoplastic resin foam sheet constituting a light reflecting member. Therefore, the method (1) (2) is preferable because the thickness of the non-foamed sheet can be easily adjusted. Among the above (1) and (2), the feed block method can be used. It is more preferable.

  Then, the above-mentioned thermoplastic resin foam sheet or thermoplastic resin non-foam sheet having light reflectivity is swelled in the vertical and horizontal directions by a large number of inverted truncated quadrangular pyramid-shaped recesses 2, 2. The light reflecting member A can be manufactured by forming the through hole 21a for disposing the light source in the bottom surface portion 21 of the recess 2 across the front and rear surfaces.

  Further, the light transmissive light diffusing sheet B is not particularly limited as long as it has light transmissive properties and light diffusing properties. For example, the light transmissive light diffusing sheet B includes a synthetic resin sheet containing a light diffusing agent and a light diffusing agent. Synthetic resin sheet with a coating film formed on the surface, synthetic resin sheet with concavo-convex processing on the surface, frosted glass (matte glass), flexible face sheet (Flexible Face Sheet), equipped with light diffusibility and light transmission Examples include woven fabrics. In addition, the light transmissive light-diffusion sheet B may be used independently or 2 or more types may be used together.

  Examples of the synthetic resin constituting the synthetic resin sheet include polymethyl methacrylate and polycarbonate. Examples of the light diffusing agent include silicone resin particles and particles made of a synthetic resin that is incompatible with the synthetic resin constituting the synthetic resin sheet.

  And as shown in FIG. 1, the illumination body L is comprised by arrange | positioning the light reflection member A, the light transmissive light diffusion sheet B mentioned later, and the light emitting diode C as a light source in the housing | casing 3. As shown in FIG. Has been.

  The housing 3 has a size that is slightly larger than the light reflecting member A, or a flat rectangular bottom surface portion 31 having a size that allows a plurality of light reflecting members A to be laid in the vertical and horizontal directions. The bottom surface portion 31 includes a rectangular frame-shaped peripheral wall portion 32 extending upward from the four-side outer peripheral edge. The upper end of the inner peripheral surface of the peripheral wall portion 32 is formed with a step portion 32a over the entire periphery, and the light transmissive light diffusion sheet B is detachably disposed on the step portion 32a. ing. The light source of the illuminator C may be a general-purpose light source in addition to the light emitting diode, but is preferably a light emitting diode.

  The light reflecting member A is disposed on the inner bottom surface of the bottom surface portion 31 of the housing 3 such that the opening of the recess 2 is on the opening side of the housing 3. In the light reflecting member A, the upper surface of the bottom surface portion 21 of each recess 2 and the reflecting surface 24a of the connecting portion 24 and the upper surface of the bottom surface portion 31 of the housing 3 are arranged in parallel to each other.

  Further, the light emitting diode C is projected forward through the through hole 21a of the bottom surface portion 21 of the recess 2 in the light reflecting member A, and the light emitting diode C is disposed on the light source disposing portion 23 of the light reflecting member A. Yes. And the light emitting diode C arrange | positioned at each recessed part 2 is comprised so that lighting and extinction are respectively independently possible. In addition, the luminescent color of the light emitting diode C is not specifically limited, For example, white, blue, green, yellow, red etc. are mentioned, You may use combining the light emitting diode C which has a different luminescent color.

  Further, a light transmissive light diffusing sheet B is detachably disposed on the step portion 32a of the peripheral wall portion 32 of the casing 3, and the light transmissive light diffusing sheet B includes the light reflecting member A and the light reflecting member A. It is preferable that the light-emitting diode C disposed on the member A is not in contact with the light-emitting diode C and is disposed at a predetermined distance forward from the opening end of the concave portion 2 of the light reflecting member A. The light transmissive light diffusion sheet B is disposed so as to be parallel to the bottom surface portion 21 of the concave portion 2 of the light reflecting member A. Further, the light transmissive light diffusing sheet B is disposed so as to be parallel to the reflecting surface 24a of the connecting portion 24 of the light reflecting member A.

The illuminating body L configured as described above passes through the light source C disposed on the light source disposition portion 23 of the recesses 2 and 2 between the recesses 2 and 2 adjacent to each other and transmits the light transmissive light diffusion sheet B. It has the structure which satisfy | fills the following conditions in the arbitrary cut surfaces cut | disconnected by the surface orthogonal to. When two arbitrary recesses 2 and 2 are defined, the other light-emitting diodes C on the light source disposition portion 23 of both recesses 2 and 2 are placed on the straight line connecting the points C ₁ and C ₁ on the other side. When the recess 2 is not interposed, the two recesses 2 and 2 are adjacent to each other.

Specifically, as shown in FIG. 4, a straight line P ₁ passing through the light emitting diode C and orthogonal to the light transmissive light diffusing sheet B is drawn. Then, contact the light reflecting surface 22c of the through light emitting diodes C and recesses 2 and draw a straight line P ₂ where the angle formed between the straight line P ₁ is minimized.

The procedure to draw a straight line P _2, 4 and 5, draws a virtual straight line that overlaps the straight line P _1, the virtual straight line is tilted toward the open end of the recess 2 around the light emitting diode C, and a virtual straight line beginning a straight line P ₂ a virtual straight line at the time when a position in contact with the light reflecting surface 22c of the recess 2 in. An angle formed by the straight line P ₂ and the straight line P ₁ is α (°). In the present invention, “passing through the light emitting diode C” means “passing through a point C ₁ on the surface of the light emitting diode C on the cut surface and in the center in the left-right direction of the light emitting diode C”. .

This angle α can be calculated in the following manner. When a straight line P ₅ orthogonal to the straight line P ₁ is drawn from a contact point 2a between the light reflecting surface 22c of the concave portion 2 and the straight line P ₂ , and the intersection of the straight line P ₅ and the straight line P ₁ is a point X, light is emitted. Let h ₁ be the distance between the point C ₁ and the point X on the diode. Further, the distance between the points C ₁ and C ₁ on the light emitting diodes C and C of the adjacent recesses 2 and 2 is d ₀ , and the contact between the light reflecting surface 22c and the straight line P 2 between the adjacent recesses 2 and ₂ is performed. point 2a, the distance between 2a and d _1. Then, the angle α (°) can be calculated based on the following equation.
α (°) = tan ⁻¹ [(d ₀ −d ₁ ) / 2h ₁ ]

Further, as shown in FIG. 6, the intersection of the straight lines P ₂ and P ₂ drawn in the above-described manner in the recesses 2 and 2 adjacent to each other is defined as Y, and passes through the intersection Y and passes through the light transmissive light diffusion sheet. A straight line P ₃ orthogonal to B is drawn, and a point where the straight line P ₃ intersects the light transmissive light diffusing sheet B is defined as B _1, and a straight line P ₄ passing through the point B ₁ and the light emitting diode C is drawn. An angle formed by the straight line P ₄ and the straight line P ₁ is β (°).

This angle β can be calculated as follows. On the straight line P ₁ , when the distance from the point C ₁ on the light emitting diode C to the rear surface of the light transmissive light diffusing sheet B is h ₀ , the angle β (°) can be calculated based on the following formula. .
β (°) = tan ⁻¹ (d ₀ / 2h ₀ )

The angle θ is a light emission angle of the light source (light emitting diode) C, and is measured in the following manner. As shown in FIG. 7, a light emitting diode C to be measured is prepared. A luminance meter K is arranged at a position 50 cm away from the point C ₁ on the light emitting diode C on a straight line perpendicular to the light source arrangement portion 23 from the point C ₁ on the light emitting diode C. As the luminance meter, for example, a spot luminance meter marketed under the trade name “CS-1000” from Konica Minolta, Inc., a spot luminance marketed under the trade name “BM-7” from Topcon Technohouse, Inc. A spectral radiance meter commercially available from Topcon Techno House under the trade name “SR-3AR” can be used.

Next, after the light emitting diode C is turned on, the luminance meter K is moved on a circle with a radius of 50 cm centered on the point C ₁ on the light emitting diode C, and the luminance meter is scanned at intervals of 1 ° to emit light. The brightness of the light emitted from the diode C is measured. Note that the measurement conditions of luminance by the luminance meter K are a measurement angle of 1 °, an ND filter of 10%, and an average number of times of 3 times / point.

In FIG. 7, a point E ₁ at which light from the light emitting diode C is no longer measured on the right side of the point C ₁ on the light emitting diode C, and a point from the light emitting diode C on the left side of the point C ₁ on the light emitting diode C. light is identified and E ₂ that are no longer measured, connecting a line F ₁ connecting the C ₁ and the point E ₁ point on the light emitting diode C, the C ₁ and the point E ₂ points on the light emitting diode C line An angle that is ½ of the angle formed by F ₂ is defined as θ.

In the illuminating body L of the present invention, the light emission angle θ and the angles α and β defined as described above satisfy the following expressions 1 and 2.
α = β Equation 1
α <θ Equation 2

In the illuminating body L of the present invention, the light emitted from the light emitting diode C disposed in the light source disposing portion 23 of one of the recesses 2 is configured so that the angle α and the angle β are the same angle. One of the light-transmitting light diffusing sheet B portions located in front of the connecting portion 24 formed between the contact points 2a and 2a between the straight line P2 and the light reflecting surface 22c in the concave portions 2 and 2 adjacent to each other. The light emitted from the light emitting diode C disposed on the light source disposing portion 23 of the other concave portion 2 illuminates one half of the two sides, that is, the half on the one concave portion 2 side. 2 of the light transmissive light diffusing sheet B located in front of the connecting portion 24 formed between the contact points 2a and 2a between the straight line P2 and the light reflecting surface 22c in FIG. That is, the other half of the concave portion 2 is illuminated. Therefore, the light emitted from the light emitting diodes C and C disposed in the recesses 2 and 2 adjacent to each other does not interfere with each other before reaching the light transmissive light diffusing sheet B. The corresponding light transmissive light diffusing sheet B portion can be illuminated with a precise color and a clear outline.

  When one of the light emitting diodes C and C disposed in the recesses 2 and 2 adjacent to each other is turned on, and the other light emitting diode C is turned off, the light emitting diode that is turned on is turned on. The light emitted from the light-emitting diode C is turned on in the light transmissive light diffusion sheet B portion located in front of the concave portion 2 in which the light emitting diode C is disposed and the connection portion 24 connecting the concave portions 2 and 2. Since the light is mainly incident on the light transmissive light diffusing sheet B portion located in front of the half of the light emitting diode C side, only the light transmissive light diffusing sheet B portion corresponding to the light emitting diode C is lit. It can be illuminated with a clear outline.

  When α−β <0 °, the light emitted from the light emitting diodes C and C disposed in the light source disposing portions 23 and 23 of the recesses 2 and 2 adjacent to each other is emitted from the recesses 2 and 2. The light-transmitting light diffusing sheet B part located in front of the connecting part 24 that connects them is not covered, and the light-transmitting light diffusing sheet B part located in front of the connecting part 24 has a light emitting diode C, A portion where the light emitted from C does not directly enter is generated, and this portion becomes very dark and luminance unevenness occurs, which is not preferable.

  When α−β> 10 °, the light emitted from the light-emitting diodes C and C disposed in the light source disposition portions 23 and 23 of the recesses 2 and 2 adjacent to each other is converted into the recesses 2 and 2. The light transmissive light diffusing sheet B is colored with the color of light emitted from the light emitting diode C, causing interference before reaching the portion of the light transmissive light diffusing sheet B positioned in front of the connecting portion 24 that connects them. It becomes difficult to illuminate. Further, when the light emitting diode C in one recess 2 is turned on while the light emitting diode C in the other recess 2 is turned off, the light transmissive light diffusion illuminated by the light emitting diode C in one recess 2 There is a possibility that the outline of the sheet B portion becomes unclear.

  However, when light is emitted from the light emitting diode C in the illuminating body L of the present invention, since the light emission angle θ has an angle larger than the angle α (Equation 2), the emitted light from the light emitting diode C is changed to the concave portion 2. The light can be dispersed by reliably entering the light reflecting surface 22c and reflecting the light on the light reflecting surface 22c. By making the dispersed light incident on the light transmissive light diffusing sheet B, the light transmissive light diffusing sheet B corresponding to each concave portion 2 is provided with uniform brightness by the light emitting diodes C disposed in the concave portions. It can be illuminated with a clear outline.

  Of the light incident on the light transmissive light diffusing sheet B as described above, a part of the light is transmitted through the light transmissive light diffusing sheet B, while a part of the light is transmitted by the light transmissive light diffusing sheet B. Reflected on the reflecting member A side.

  The light reflected on the light reflecting member A side is reflected again on the light transmissive light diffusing sheet B side by the light reflecting surface 22c of the concave portion 2 of the light reflecting member A and the reflecting surface 24a of the connecting portion 24. In this light reflection, when the front surface of the connection portion 24 of the light reflection member A is formed on the entire flat reflection surface 24a, the light incident on the reflection surface 24a of the connection portion 24 is converted to the light transmissive light diffusion sheet B side. In particular, the light-transmitting light diffusing sheet B positioned in front of the connecting portion 24 and the vicinity thereof can be reliably reflected and radiated from the light-emitting diodes C and C disposed in the adjacent recesses 2 and 2. Interference between the emitted lights can be suppressed as much as possible, and the light transmissive light diffusing sheet B portion located in front of the connection portion 24 can be illuminated with a clear outline in a desired color. In this manner, the light emitted from the light emitting diode C passes through the light transmissive light diffusion sheet B while repeating multiple reflections between the light reflecting member A and the light transmissive light diffusion sheet B.

  As described above, the light emitted from the light emitting diode C is incident on the light transmissive light diffusing sheet B while repeating multiple reflections between the light reflecting member A and the light transmissive light diffusing sheet B. The light diffusing sheet B is separated from the light emitting diode C between the portion in front of the recess 2 of the light reflecting member A and the portion that is not, that is, the portion in front of the connecting portion 24 of the light reflecting member A. There is almost no difference in the light irradiation intensity. Therefore, in the portion where the light emitting diode C is lit, the occurrence of luminance unevenness of the light transmissive light diffusion sheet B is suppressed.

  And when the light reflection member A of the illuminating body L of the present invention has the connecting portion 24 between the recesses 2 and 2, the shape of the connecting portion 24 is changed by adjusting its width or the like. The arrangement interval of the light emitting diodes C can be changed without changing the shape of the recess 2.

  Therefore, the illuminating body L of the present invention flexibly supports the shape of the concave portion 2, the arrangement state of the light emitting diode C, the existing product in which the distance between the light emitting diode C and the light transmissive light diffusing sheet B is fixed in advance. can do.

  Further, the light reflecting member A of the illuminating body L of the present invention has a flat reflecting surface 24a formed on the front surface of the connecting portion 24 connecting the recesses 2 and 2, so that the light reflecting surface of the recess 2 is formed. Without changing the inclination angle of 22c, the depth of the recess 2 can be made shallower than when the recesses 2 and 2 are connected by a connection portion having an inverted V-shaped cross section. The illuminating body L can be made thin.

  In addition, if the front surface of the connecting portion 24 that connects the recesses 2 and 2 is a flat surface, interference between the light emitted from the light emitting diodes C and C disposed in the recesses 2 and 2 adjacent to each other. The light from the light emitting diode C can be sufficiently incident on the light transmissive light diffusing sheet B located in front of the connecting portion 24 and in the vicinity thereof by multiple reflection. Therefore, the illuminating body L of the present invention can reduce the thickness while suppressing the occurrence of luminance unevenness of the light transmissive light diffusing sheet B.

Further, as shown in FIG. 6, between the adjacent recesses 2, 2, the light passes through the light source C provided on the light source disposition portion 23 of the recesses 2, 2 and into the light transmissive light diffusion sheet B. A tangent line P ₆ at an arbitrary point on the light reflecting surface 22c of the recess 2 is drawn by a cut surface cut by a plane orthogonal to the surface, and the tangent line P ₆ and a plane parallel to the light transmissive light diffusion sheet B are drawn. When the angle formed by γ is γ (°), 0 to 80 ° is preferable, and 20 to 60 ° is more preferable. Incidentally, when selecting an arbitrary point in the light reflecting surface 22c, when the light reflecting surface 22c part this point there is a flat surface having a certain inclination angle, replaced a tangent P ₆ and the light reflecting surface 22c portion Shall.

  If the angle γ is too large, the light emitted from the light-emitting diode C and reflected by the light reflecting surface 22c of the recess 2 is less likely to be reflected in the direction of the connecting portion 24 and is more likely to be reflected toward the front of the recess 2. As a result, the light irradiation intensity in the light transmissive light diffusing sheet B portion corresponding to the front of the connection portion 24 of the light reflecting member A is greater than the light irradiation intensity in the light transmissive light diffusing sheet B portion corresponding to the front of the recess 2. This is because the brightness becomes weak and uneven luminance occurs in the light transmissive light diffusion sheet B in the light irradiation region from each light emitting diode C.

  The light reflecting surface 22c of the concave portion 2 is formed from a flat surface, and the angle γ does not change. However, like the concave portion 2 shown in FIGS. The inclination angle may be changed. In such a case, the angle γ is configured to increase as it goes from the front side to the rear side of the recess 2, that is, as the light transmissive light diffusion sheet B is approached. It is preferable.

  Therefore, when all the light emitting diodes C, C... That are the light sources of the illuminating body configured as described above are turned on, each light emitting diode C is in the light transmissive light diffusing sheet B as described above. The corresponding portion is illuminated with uniform brightness, and the light-transmissive light diffusing sheet B is illuminated with uniform brightness as a whole with an accurate color emitted from each light emitting diode.

  Then, among the light-emitting diodes C, C... Disposed in the recess 2, only a part of the light-emitting diodes C is turned on, while the remaining light-emitting diodes C are turned off, whereby the light transmissive light diffusion sheet B is turned on. The desired portion can be illuminated with an accurate color and a clear outline according to the color of light emitted from each light emitting diode.

  Therefore, by turning on and off the light emitting diodes C of the light emitting diodes C, C... Disposed in the recess 2 independently of each other, only a desired portion of the light transmissive light diffusing sheet B is clearly defined. For example, by controlling the illumination portion of the light transmissive light diffusing sheet B to be a desired pattern or a desired character, it can be used for applications such as a display device or an advertising medium.

  Further, for example, the illumination portion of the light transmissive light diffusing sheet B is time-lapsed by controlling the light emitting diodes C, C... In addition, it is possible to change the design, characters, etc. projected on the light transmissive light diffusing sheet B with time.

  When the illumination body is used as a backlight for liquid crystal display, the light emitting diode C corresponding to the portion to be displayed in black in the display screen is turned off in conjunction with the liquid crystal panel, thereby It is possible to prevent the incidence of light on the portion to be displayed in black and to clarify the black portion of the portion to be displayed in black to improve the contrast.

  Although the case where the concave portion 2 is formed in a reverse truncated quadrangular pyramid shape has been described above, the concave portion 2 may have a reverse truncated pyramid shape other than the reverse truncated quadrangular pyramid shape. The truncated cone shape means a shape obtained by excising the top of the cone.

  Specifically, as shown in FIGS. 8 and 9, in the recess 2 of FIG. 1, the bottom surface portion 21 is formed in a regular octagonal shape, and the peripheral wall piece portions 22 a and 22 a are connected to each other in an isosceles triangular shape. A structure formed in a funnel shape by continuously connecting in the circumferential direction of the bottom surface portion 21 via 22b ′ may be used. Also in this recessed part 2, it is necessary to satisfy | fill said Formula 1 and Formula 2. Since the structure of the light reflection member A other than the above has the same structure as the light reflection member A shown in FIG.

  Further, as shown in FIGS. 10 and 11, the concave portion 2 is extended in a state in which the bottom surface portion 41 has a regular hexagonal shape and gradually expands forward from the four-side outer periphery of the bottom surface portion 41. The shape which consists of the surrounding wall part 42 may be sufficient.

  In the peripheral wall portion 42, six inverted isosceles trapezoidal peripheral wall pieces 42a, 42a,... Share the opposite inclined sides over the entire length between the adjacent peripheral wall piece portions 42a, 42a. As a result, a continuous funnel shape is formed continuously in the circumferential direction of the bottom surface portion 41, and the inner surface of the continuous portion 42b between the peripheral wall piece portions 42a, 42a is a smooth concave arc surface that is not cut or cracked over the entire length. The inner peripheral surface of the peripheral wall portion 42 is formed entirely on the light reflecting surface 42c that reflects the light emitted from the light source C. Furthermore, the inner surface of the connecting portion between the peripheral wall portion 42 and the bottom surface portion 41 is also formed into a smooth concave arc surface, preferably a concave arc surface, that is completely free of cuts and cracks. Also in this recessed part 2, it is necessary to satisfy | fill said Formula 1 and Formula 2. Since the structure of the light reflection member A other than the above has the same structure as the light reflection member A shown in FIG.

  Moreover, as shown in FIG.12 and FIG.13, the recessed part 2 may be formed in the reverse truncated cone shape other than the inverted truncated pyramid shape. That is, the concave portion is formed by a planar circular bottom surface portion 61 and an inverted frustoconical peripheral wall portion 62 extending in a state of gradually expanding from the outer peripheral edge of the bottom surface portion 61 toward the front. It may be. Also in this recessed part 2, it is necessary to satisfy | fill said Formula 1 and Formula 2. The structure of the light reflecting member A other than the above has the same structure as the light reflecting member A shown in FIG.

  In the above, the inclination angle of the light reflecting surface of each peripheral wall piece part constituting the peripheral wall part forming the concave part 2, that is, the angle γ reaches from the bottom part of the concave part 2 to the opening end of the concave part 2 Although the case where it has the same angle without changing has been described, the inclination angle of the light reflecting surface of each peripheral wall piece part constituting the peripheral wall part forming the concave part 2 is the bottom part of the concave part 2 It may change between 21 and the opening end 2a of the recess 2.

  Specifically, as shown in FIGS. 14 to 16, the concave portion 2 is extended in a state of gradually expanding from the outer peripheral edge of the bottom surface portion 51 to the front side with a flat square bottom surface portion 51. And a peripheral wall portion 52.

  The peripheral wall portion 52 is composed of four peripheral wall pieces 52a, 52a,... Between the adjacent peripheral wall pieces 52a, 52a by sharing the inclined sides facing each other over the entire length. It is continuously provided integrally in the circumferential direction and formed in a funnel shape.

Each peripheral piece portion 52a, the longitudinal direction of the two positions of the bent portion 52b, which is bent in the standing direction in 52c, the angle gamma ₁ in peripheral piece portion 52a portion of the rearward of the bent portion 52b, a bent portion 52b When the angle γ ₂ in the peripheral wall piece portion 52a portion between the bent portions 52c and the angle γ ₃ in the peripheral wall piece portion 52a portion ahead of the bent portion 52c are compared, the angle γ ₁ , the angle γ ₂ , and the angle γ ₃ are in this order. It is getting bigger. The angles γ _{1 to} γ ₃ are angles defined by the angle γ. The bent portions 52b (52c) of each peripheral wall piece portion 52a are connected in the circumferential direction of the bottom surface portion 51 to form a planar square frame shape. Also in this recessed part 2, it is necessary to satisfy | fill said Formula 1 and Formula 2. The structure of the light reflecting member A other than the above has the same structure as the light reflecting member A shown in FIG.

In the above description, in the concave portions 2, 2... Arranged in a grid pattern, the case where the edges forming the open ends of the concave portions 2 adjacent in the vertical and horizontal directions are formed in parallel to each other has been described. As shown in FIG. 2, the concave portion 2 is so formed that the arbitrary concave portion 2 and the opening end of the concave portion 2 adjacent to the concave portion 2 in the vertical and horizontal directions are rotated by 90 ° clockwise in the drawing. 2 ... may be formed. When the recesses 2, 2... Are arranged in this way, the angles α and β measured on the left and right with respect to the straight line P ₁ may not take the same value. It is necessary to satisfy Equation 1 and Equation 2 above. In addition, since the shape of the recessed part 2 is the structure similar to the recessed part 2 shown in FIG.10 and FIG.11, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the above description, the case where the concave portion 2 is formed on the substantially entire surface of the light reflecting member A and the light emitting diodes C, C,... C does not need to be disposed, and the light emitting diode C may be disposed only in a necessary recess.

  Further, it is not necessary to provide the concave portion 2 on the entire surface of the light reflecting member A. As shown in FIG. 18, the concave portions 2, 2,. For example, an illuminating body in which the light emitting diode C is disposed may be used. In this case, the light emitting diodes C arranged in the respective recesses 2 may be able to be turned on and off independently of each other, but all or some of the light emitting diodes C, C. It may be turned off. When it is not necessary to illuminate the entire surface of the light transmissive light diffusing sheet B and only a part of the light transmissive light diffusing sheet B needs to be illuminated, the light reflecting member A shown in FIG. The concave portion 2 of the light reflecting member A may be formed only in a part of the rear of the light transmissive light diffusing sheet B, and specifically corresponds to the rear of the portion of the light transmissive light diffusing sheet B that requires illumination. The concave portion 2 of the light reflecting member A may be formed only in the portion.

  Furthermore, as shown in FIG. 19, in the light reflection member A, the part in which the recessed part 2 is not formed may be cut off. Although the light reflecting member A shown in FIG. 19 is formed from a single sheet, a plurality of independent light reflecting members A may be combined. In addition, the recessed part 2 needs to satisfy | fill Formula 1 and Formula 2. FIG. The shape of the recess 2 is the same as that of the recess 2 shown in FIGS. In this way, in the light reflecting member A, the portion where the concave portion 2 is not formed is excised, and the light reflecting member A is disposed only in the rear part of the light transmissive light diffusing sheet B. By disposing the light reflecting member A only in the portion corresponding to the rear of the portion that requires illumination in the light transmissive light diffusing sheet B, the illuminating body can be reduced in weight. Further, by adjusting the shape of the light reflecting member A or the combination of the light reflecting members A, the concave portions 2 of the light reflecting member A disposed behind the light transmissive light diffusing sheet B can be easily arranged in a desired arrangement state. The light-emitting diode C can be easily disposed in correspondence with the portion of the light transmissive light diffusing sheet B that requires illumination.

  In this way, the light reflecting member A is disposed only in the portion corresponding to the rear of the portion requiring illumination in the light transmissive light diffusing sheet B, or the concave portions 2 of the light reflecting member A are disposed in a desired arrangement. Thus, a part of the light transmissive light diffusing sheet B can be illuminated so as to have a desired pattern or a desired character, and can be used for applications such as advertising media. Then, by making the light emitting diodes C disposed in the recesses 2 of the light reflecting member A can be turned on and off independently of each other, a desired portion of the light transmissive light diffusing sheet B can be changed to a different desired pattern, desired character, etc. It can also be illuminated.

  Further, for example, the illumination portion of the light transmissive light diffusing sheet B is time-lapsed by controlling the light emitting diodes C, C... In addition, it is possible to change the design, characters, etc. projected on the light transmissive light diffusing sheet B with time.

  In the light reflecting member A, the case where the concave portions 2 and 2 are connected by the connecting portion 24 has been described. However, as shown in FIGS. 20 and 21, the connecting portion 24 is formed between the concave portions 2 and 2. Instead, the opening edges of the recess 2 may be joined directly. In addition, the recessed part 2 needs to satisfy | fill Formula 1 and Formula 2. FIG. The shape of the recess 2 is the same as that of the recess 2 shown in FIGS.

( Comparative Example 5 )
A light reflecting sheet serving as a raw fabric of the light reflecting member A was prepared. In this light reflecting sheet, a thermoplastic resin non-foamed sheet was laminated and integrated on one surface of the thermoplastic resin foamed sheet. The light reflecting sheet had a thickness of 0.8 mm and an overall density of 0.8 g / cm 3. The light reflecting sheet has a total light reflectance of 98.5%, a diffuse reflectance of 96.3%, and a ratio of the diffuse reflectance to the total light reflectance of 97.8% on the surface of the thermoplastic resin non-foamed sheet. Met.

  A planar light-reflective sheet having a side of 35 cm was cut out from the light-reflecting sheet. After heating the light reflecting raw sheet so that the surface temperature becomes 140 ° C., a part of the light reflecting raw sheet is moved from the thermoplastic resin non-foamed sheet side to the thermoplastic resin foamed sheet side by match molding. .., Swelled, and connected to the substantially entire surface of the light reflection raw sheet by connecting the recesses 2, 2... It formed continuously in the length and breadth without forming a part. A planar square through hole 21a is provided between the front and rear surfaces of the bottom surface portion 21 of each recess 2, and the light emitting diode C is formed on the light source arrangement portion 23 formed by the inner bottom surface of the bottom surface portion 21 through the through hole 21a. Was formed to be distributable. The bottom surface portion 21 of the recess 2 was formed in a planar square shape having a side of 20 mm. The open end of the recess 2 was formed in a planar square shape with one side of 50 mm.

  Then, a light-reflective member A having a planar square shape with a side of 15 cm was obtained from the light-reflecting raw sheet having the concave portion 2 bulged. In the light reflecting member A, the edge direction of the entire shape is matched with the opening edge direction of the recess 2.

  The inner surface of the continuous wall 22b between the peripheral wall pieces 22a and 22a of the recess 2 is formed into a smooth concave arc surface with no cuts or cracks over the entire length, and the inner peripheral surface of the peripheral wall 22 is entirely formed. The light reflecting surface 22c that reflects the light emitted from the light emitting diode C is formed. The inner surface of the connecting portion between the peripheral wall portion 22 and the bottom surface portion 21 was also formed as a smooth concave arc surface without any cuts or cracks. Further, the opening edges of the recesses 2 and 2 are directly joined to each other, and the joint part between the opening edges of the recesses 2 and 2 is formed on a smooth convex arc surface that is not cut or cracked entirely. It had been.

  Next, it is composed of a flat square bottom surface portion 31 having a side of 15.5 cm and a square frame-shaped peripheral wall portion 32 having a height of 4.5 cm and extending upward from the four-side outer periphery of the bottom surface portion 31. A housing 3 was prepared. A stepped portion 32a was formed on the inner peripheral surface upper end portion of the peripheral wall portion 32 of the housing 3 over the entire periphery.

  A light emitting diode module unit in which a light emitting diode C is arranged at the center of the upper surface of the substrate is laid on the inner bottom surface of the housing 3 in a state where the light emitting diode C faces forward, without any gaps. A module was formed, and the light reflecting member A was laid on the light emitting diode module. The light emitting diodes C, C,... Are disposed on the light source arrangement portions 23, 23,. The operating power of one light emitting diode module was 0.48W. The light emission angle θ of the light emitting diode C was 80 °.

  A light transmissive light diffusing sheet B (trade name “Acrylite” manufactured by Mitsubishi Rayon Co., Ltd., thickness 2 mm, total light transmittance: 58%) is detachably disposed on the step 32a of the housing 3. The illuminating body L was produced. The bottom surface portion 21 of the concave portion 2 of the light reflecting member A, the front and back surfaces of the light transmissive light diffusing sheet B, and the bottom surface portion 31 of the housing 3 were arranged so as to be parallel to each other.

Between the recesses 2 and 2 adjacent to each other of the obtained illuminating body L, the light passes through the light-emitting diodes C disposed on the light source disposition portion 23 of the recesses 2 and 2 and is directed to the light transmissive light diffusion sheet B. In a plane that is orthogonal and cut along a plane parallel to the edge of the opening edge of the recess 2 (first surface) and a plane parallel to the diagonal direction (second surface) at the opening edge of the recess 2 , The angle α, the angle β, the angle γ, the distance h ₀ from the point C ₁ on the light emitting diode C to the rear surface of the light transmissive light diffusion sheet B, and the distance h between the point C ₁ and the point X on the light emitting diode ₁ and the distance d ₀ between the points C ₁ and C ₁ on the light emitting diodes C and C of the adjacent recesses 2 and 2 are as shown in Tables 1 and 2.

( Comparative Example 6 )
The recesses 2 and 2 are formed at regular intervals, and the recesses 2 and 2 adjacent to each other are entirely connected by the connecting portion 24 formed on the reflection surface 24a having a flat front surface. The illuminator L was obtained in the same manner as in Comparative Example 5 except that the bottom surface portion 21 was formed in a planar square shape having a side of 15 mm and the open end was formed in a planar square shape having a side of 40 mm. The connecting portion between the opening end of the recess 2 and the connection portion 24 was entirely formed on a smooth convex arc surface having no cuts or cracks. The bottom surface portion 21 of the concave portion 2 of the light reflecting member A and the reflection surface 24a of the connection portion 24, the front and back surfaces of the light transmissive light diffusing sheet B, and the bottom surface portion 31 of the housing 3 are arranged in parallel to each other. It had been.

Between the recesses 2 and 2 adjacent to each other of the obtained illuminating body L, the light passes through the light-emitting diodes C disposed on the light source disposition portion 23 of the recesses 2 and 2 and is directed to the light transmissive light diffusion sheet B. In a plane that is orthogonal and cut along a plane parallel to the edge of the opening edge of the recess 2 (first surface) and a plane parallel to the diagonal direction (second surface) at the opening edge of the recess 2 , The angle α, the angle β, the angle γ, the distance h ₀ from the point C ₁ on the light emitting diode C to the rear surface of the light transmissive light diffusion sheet B, and the distance h between the point C ₁ and the point X on the light emitting diode ₁ , the distance d ₀ between the points C ₁ and C ₁ on the light emitting diodes C and C of the adjacent recesses 2 and 2, and the width dimension d ₁ of the connecting portion 24 are as shown in Tables 1 and 2.

(Example 1 )
The concave portion 2 has a bottom surface portion 21 formed in a planar square shape with a side of 10 mm and an opening end formed in a planar square shape with a side of 30 mm, and a planar square bottom surface portion 31 with a side of 15.5 cm. Illuminating body in the same manner as in Comparative Example 6 except that the casing 3 is used, which is formed by a rectangular frame-shaped peripheral wall portion 32 having a height of 5 cm and extending upward from the four-side outer periphery of the bottom surface portion 31. L was obtained.

Between the recesses 2 and 2 adjacent to each other of the obtained illuminating body L, the light passes through the light-emitting diodes C disposed on the light source disposition portion 23 of the recesses 2 and 2 and is directed to the light transmissive light diffusion sheet B. In a plane that is orthogonal and cut along a plane parallel to the edge of the opening edge of the recess 2 (first surface) and a plane parallel to the diagonal direction (second surface) at the opening edge of the recess 2 , The angle α, the angle β, the angle γ, the distance h ₀ from the point C ₁ on the light emitting diode C to the rear surface of the light transmissive light diffusion sheet B, and the distance h between the point C ₁ and the point X on the light emitting diode ₁ , the distance d ₀ between the points C ₁ and C ₁ on the light emitting diodes C and C of the adjacent recesses 2 and 2, and the width dimension d ₁ of the connecting portion 24 are as shown in Tables 1 and 2.

(Comparative Example 1)
A case 3 comprising a flat square-shaped bottom surface portion 31 having a side of 15.5 cm and a square frame-shaped peripheral wall portion 32 having a height of 5 cm and extending upward from the four-side outer periphery of the bottom surface portion 31 is used. An illuminator L was obtained in the same manner as in Comparative Example 5 except that.

Between the recesses 2 and 2 adjacent to each other of the obtained illuminating body L, the light passes through the light-emitting diodes C disposed on the light source disposition portion 23 of the recesses 2 and 2 and is directed to the light transmissive light diffusion sheet B. In a plane that is orthogonal and cut along a plane parallel to the edge of the opening edge of the recess 2 (first surface) and a plane parallel to the diagonal direction (second surface) at the opening edge of the recess 2 , The angle α, the angle β, the angle γ, the distance h ₀ from the point C ₁ on the light emitting diode C to the rear surface of the light transmissive light diffusion sheet B, and the distance h between the point C ₁ and the point X on the light emitting diode ₁ and the distance d ₀ between the points C ₁ and C ₁ on the light emitting diodes C and C of the adjacent recesses 2 and 2 are as shown in Tables 1 and 2.

(Comparative Example 2)
The concave portion 2 is obtained in the same manner as in Example 1 except that the bottom surface portion 21 is formed in a planar square shape having a side of 10 mm and the opening end is formed in a planar square shape having a side of 25 mm. It was.

Between the recesses 2 and 2 adjacent to each other of the obtained illuminating body L, the light passes through the light-emitting diodes C disposed on the light source disposition portion 23 of the recesses 2 and 2 and is directed to the light transmissive light diffusion sheet B. In a plane that is orthogonal and cut along a plane parallel to the edge of the opening edge of the recess 2 (first surface) and a plane parallel to the diagonal direction (second surface) at the opening edge of the recess 2 , The angle α, the angle β, the angle γ, the distance h ₀ from the point C ₁ on the light emitting diode C to the rear surface of the light transmissive light diffusion sheet B, and the distance h between the point C ₁ and the point X on the light emitting diode ₁ , the distance d ₀ between the points C ₁ and C ₁ on the light emitting diodes C and C of the adjacent recesses 2 and 2, and the width dimension d ₁ of the connecting portion 24 are as shown in Tables 1 and 2.

(Comparative Example 3)
An illuminator L was produced in the same manner as in Comparative Example 5 except that a planar square plate having a side of 15 cm was cut out from the light reflecting raw sheet and used as a light reflecting member.

(Comparative Example 4)
An illuminator L was produced in the same manner as in Example 1 except that a flat T-shaped flat plate was cut out from the light reflecting raw sheet and used as a light reflecting member.

  When all of the light emitting diodes C arranged in the concave portion 2 of the illuminating body L were turned on, a T-shaped image having a clear outline could not be confirmed on the light transmissive light diffusing sheet B.

The luminances of the illuminators obtained in Example 1 and Comparative Examples 1 to 3 , 5 and 6 were measured in the following manner, and the results are shown in Table 4.

(Luminance evaluation of lighting body)
A two-dimensional luminance meter M (trade name “CA-2000, manufactured by Konica Minolta Co., Ltd.) is located 50 cm away from the center of the light transmissive light diffusing sheet B of the illuminator L in a direction orthogonal to the light transmissive light diffusing sheet B. )).

  Thereafter, all the light emitting diodes C, C... Of the illuminating body L were turned on, and the luminance was measured using the two-dimensional luminance meter M (when the entire surface was turned on). Note that the measurement conditions were a synchronous setting of 60 Hz: 1/30, an ND filter of 1.5%, a dark color allowable value of 5.0%, and an integration count of 64 times.

  Measure the brightness (light source part brightness) of the part corresponding to the front of the light emitting diodes arranged on the light source arrangement part 23 of each concave part 2 in the light reflecting member A (vertical direction 3 places × lateral direction 3 places = 9 places). The arithmetic average value is shown in Table 3 as the average light source luminance.

  Similarly, the luminance (non-light source portion luminance) of the portion corresponding to the front side of the reflecting surface 24a of the connecting portion 24 of the light reflecting member A (vertical direction 2 places × lateral direction 2 places = 4 places) is measured. The average value is shown in Table 3 as the average non-light source luminance.

Further, the luminance of the entire range of the light reflecting member A was measured, and the arithmetic average value of the luminance was defined as the average overall luminance. In addition, since the connection part was not formed in the light reflection member A of the comparative example 5 and the comparative example 1, the continuous connection part of the opening edges of the recessed parts 2 and 2 was considered as a connection part, and the non-light source brightness | luminance was measured. . Since the light reflecting member A of Comparative Example 3 is not formed with a recess and a connecting part, the light source unit luminance and the non-light source unit luminance were measured at the same measurement locations as in Comparative Example 5 .

  In addition, Table 3 shows luminance unevenness as a value obtained by multiplying a value obtained by dividing the difference between the maximum luminance when the light source unit luminance is measured and the minimum luminance when the non-light source unit luminance is measured by the average overall luminance. did.

  Next, eight light-emitting diodes C other than the light-emitting diode C located at the center among the light-emitting diodes C, C. , C... Were lit (when partially lit).

  The luminance of the portion corresponding to the front of the lit light emitting diode C (lighting portion luminance) was measured in the same manner as described above, and the arithmetic average value thereof is shown in Table 3 as the average lighting portion luminance. Further, the luminance of the portion corresponding to the front of the light-emitting diode C that was turned off (light-out portion luminance) was measured in the same manner as described above, and the arithmetic average value thereof is shown in Table 3 as the average light-out portion luminance.

  Subsequently, all the light emitting diodes C, C... Of the light reflecting member A are turned on, and the illumination state of the light transmissive light diffusing sheet B is shown in the column of “when fully lit” in the photograph of FIG.

  Next, the illumination state of the light transmissive light diffusing sheet B in a state where only the central light emitting diode C is turned off is shown in the column of “when the center is turned off” in the photograph of FIG.

1 Thermoplastic resin sheet
2a Open end 2 Recess 3 Housing
21 Bottom
22 Perimeter wall
22a Perimeter wall piece
22b Connection section
22c Light reflecting surface
23 Light source placement
24 connections
24a Reflective surface
41 Bottom
42 Perimeter wall
42a Perimeter wall piece
42b Connection section
42c Light reflecting surface
51 Bottom
52 Perimeter wall
52a Peripheral wall piece A Light reflecting member B Light transmissive light diffusing sheet C Light source, light emitting diode L Illuminant θ Light radiation angle

Claims (7)

A light source disposing portion for disposing a plurality of recesses by expanding a thermoplastic resin sheet having light reflectivity from the front surface to the rear surface by thermoforming, and the inner bottom surface of the recesses disposes a light source. And a light reflecting member formed on the light reflecting surface for reflecting the light emitted from the light source, and disposed in front of the light reflecting member and the light. An illuminating body having a light transmissive light diffusing sheet that is not in contact with the reflecting member, and the light source disposed in the light source disposing portion of the concave portion of the light reflecting member, between the concave portions adjacent to each other. The light emission angle of the light source is set to θ on the cut surface cut through the light source disposed in these recesses and orthogonal to the light transmissive light diffusion sheet, and the light source is And perpendicular to the light transmissive light diffusing sheet A straight line P _1, an angle formed angle formed by the straight line P ₂ that minimizes the and the straight line P ₁ into contact with the light-reflecting surface of the concave portion with through said light source and alpha, further, between recesses adjacent A straight line P ₄ passing through the point where the straight line P ₃ perpendicular to the light transmissive light diffusing sheet intersects the light transmissive light diffusing sheet and the light source from the point where the straight lines P ₂ intersect with each other, An illuminating body satisfying the following expressions 1 and 2 when β is an angle formed by the straight line P ₁ .
α = β Equation 1
α <θ Equation 2 The illumination body according to claim 1, wherein the light sources arranged in the recesses can be turned on and off independently of each other. The illuminating body according to claim 1 or 2, wherein a light reflecting member is disposed only in a part of the rear of the light transmissive light diffusing sheet. The illuminating body according to claim 1 or 2, wherein a concave portion of the light reflecting member is formed only in a part of the rear of the light transmissive light diffusing sheet. The illuminating body according to any one of claims 1 to 4 , wherein the recesses are connected by a connecting portion formed on a reflective surface having a flat front surface. The illuminating body according to any one of claims 1 to 5 , wherein the concave portion has a reverse truncated cone shape. The illuminating body according to any one of claims 1 to 5 , wherein the concave portion has a reverse truncated pyramid shape.