JP2009252447A - Light guide, illuminating device, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide which has a simple structure and less weight, is inexpensive, has a long life, and is applicable to a signboard display device and a direct/indirect illuminating device, and to provide an illuminating device and a signboard display device which use the light guide. <P>SOLUTION: The light guide includes a reflective board 12 composed of a thin board with both sides curved against a middle portion to form a rising curved surface, and a light diffusion board 13 disposed opposite to the inner curved surface of the reflective board. One of both sides of the reflective board 12 curves against the inner surface of the middle portion at 90 degrees or more, while the other side curves at less than 90 degrees. A single or a plurality of light-emitting diodes 14 are disposed near one side so that at least part of light emitted from the light-emitting diode is reflected on the inner curved surface 12a of the reflective board 12 to reach the light diffusion board 13. The inner curved surface 12a of the reflective board 12 allows the reflected light to reach the light diffusion board 13. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light guide capable of uniformly guiding light from light emitting diodes arranged linearly at predetermined intervals onto a predetermined surface, and an illumination device and a display device using the light guide as a surface light source. Is.

  Conventionally, as a surface light source used for a display device such as a lighting device or a signboard, there is a surface light source device using a large number of light emitting diodes 102 as shown in FIG. The surface light source device 100 has a configuration in which a large number of light emitting diodes 102 are arranged and mounted at a predetermined interval on the bottom of a case 101 whose top is open. The mounting surface 101a of the light emitting diode 102 of the case 101 of the surface light source device 100 having such a configuration is disposed so as to oppose an irradiated body (not shown), and light emitted from the light emitting diode 102 is not used by a light guide plate. The irradiated object is irradiated directly.

  In the surface light source device 100 configured as described above, in order to keep the illuminance at a position (case opening surface position) at a height distance D1 of the case 101 from the mounting surface 101a of the light emitting diode 102, the light emitting diode 102 that is a point light source has a height. It was arranged at an adjacent interval equal to or less than the distance D1. In the case of this method, the number of light emitting diodes 102 as point light sources must be determined by the distance D1, and the number of light emitting diodes 102 cannot be reduced. Further, when the adjacent interval is larger than the distance D1, the number of the light emitting diodes 102 can be reduced. However, since the illuminance at the distance D1 (at the position of the case opening surface) is reduced, the adjacent interval is emitted with a size smaller than the distance D1. There is also a problem that the diode 102 must be arranged and mounted, resulting in high cost.

  As one of such surface light sources, there is a surface light source described in Patent Document 1. As shown in FIG. 2, the surface light source 110 includes a light guide plate 111 that emits light incident from an illuminating lamp 112 disposed on an end surface from a first plane 111a, and a second plane 111d opposite to the first plane 111a. In addition, there are alternating top lines T and valley lines V that are parallel to each other, the valley lines V are substantially in the first virtual plane A1 parallel to the first plane 111a, and the top line T is the first plane 111a. A prism array that is parallel and is substantially present in the second imaginary plane A2 that is separated from the first plane 111a with respect to the first plane 111a is formed, and the second plane 111d is a line that is substantially parallel to the top line T and the first region. When the prism array in one region is divided into approximately two equal parts with the second region, the angle α formed between the surface on one side of each prism of the prism array and the second virtual surface A2 is the light guide plate 111 with respect to the air. Is approximately equal to the critical angle of the Angle β between the surface and the second virtual plane A2 of the other side of each prism of Zumuarei is configured to be smaller than the angle alpha. Reference numeral 114 denotes a diffusion plate, and 113 denotes a translucent liquid crystal display panel.

  The surface light source 110 of the above-mentioned Patent Document 1 has a complicated configuration such as forming a prism array on the light guide plate 111, which increases the cost, and at the same time, has a problem that the weight is heavy and the lifetime is short because the illumination lamp 112 is used as the light source. is there.

  Furthermore, there is a surface light source described in Patent Document 2 as one of surface light sources having a mountain-shaped curved surface reflecting material.

Further, the surface light source described in Patent Document 2 does not have a configuration in which light reaches the lower surface of the diffusion plate facing the light source. Therefore, there is a problem that the entire diffusion plate cannot be irradiated.
JP-A-8-94444 Japanese Patent Application Laid-Open No. 2006-284831

  The present invention has been made in view of the above points, and has a simple structure, light weight, low cost, long life, a light guide suitable for a display device such as a signboard and a direct or indirect lighting device, and a light guide. An object of the present invention is to provide a display device such as an illuminating device or a signboard using a vessel.

  In order to solve the above-mentioned problems, the present invention provides a reflecting plate made of a thin plate having both sides curved with respect to an intermediate portion to form a curved surface, and a light diffusing plate arranged to face the inner surface of the intermediate portion of the reflecting plate. One of the two sides of the reflector is curved at 90 degrees or more with respect to the inner surface of the intermediate portion, the other side is curved at 90 degrees or less, and one or more light emitting diodes are provided near the one side. At least a part of the emitted light is reflected by the curved inner surface of the reflecting plate and reaches the light diffusing plate, and the light reflected by the curved inner surface of the reflecting plate reaches the light diffusing plate surface. The light guide is characterized in that it is made to do.

  By adopting the above configuration in the light guide, part of the light emitted from the light emitting diodes arranged in the vicinity of one side of the reflector directly reaches the light diffusing plate, and part of the light is reflected by the curved inner surface of the reflector. Since the light reaches the surface of the light diffusion plate, the light diffusion plate becomes a surface light source from which light is emitted. At the same time, in the light guide of this configuration, most of the non-light-emitting portions where the light-emitting diodes are arranged are covered with a reflecting plate, and one side where the light-emitting diodes are arranged is curved by 90 degrees or more. The light emitting diode arrangement area viewed from the direction of the diffusion plate is reduced, and the reflection characteristics inside the light guide can be improved. The curved surface of the reflecting plate is formed so that the light is uniform on the light diffusing plate surface, and the material constituting the reflecting plate is selected. The material constituting the reflector is a material that efficiently reflects the reached light toward the light diffuser, for example, a foamed light reflector made of a foamed resin material having a total reflectance of 90% or more and a diffuse reflectance of 90% or more. Is used.

  Further, the present invention provides a reflecting plate array having a configuration in which a plurality of reflecting plates made of a thin plate having both sides curved with respect to an intermediate portion to form a rising curved surface and arranged adjacent to each other, and each reflecting plate of the reflecting plate row A light diffusing plate disposed to face the inner surface of the intermediate portion, and one side of each of the reflecting plates of the reflecting plate row is curved at 90 degrees or more with respect to the inner surface of the intermediate portion. Is bent at 90 degrees or less, and one or a plurality of light emitting diodes are arranged in the vicinity of the one side so that at least part of the light emitted is reflected by the curved inner surface of the reflecting plate and reaches the light diffusing plate. In the light guide, the light reflected by the curved inner surface of the reflector plate reaches the light diffusion plate surface.

  By adopting the above configuration in the light guide, part of the light emitted from the light emitting diodes arranged in the vicinity of one side of each reflector in the reflector array directly reaches the light diffuser, and part of the reflector Are reflected by the curved inner surface of the other reflector plate and reach the light diffusing plate surface, the light diffusing plate straddling each reflecting plate becomes a surface light source from which light is radiated. At the same time, in the light guide of this configuration, most of the non-light-emitting portions where the light-emitting diodes are arranged are covered with a reflecting plate, and one side where the light-emitting diodes are arranged is curved by 90 degrees or more. The light emitting diode arrangement area viewed from the direction of the diffusion plate is reduced, and the reflection characteristics inside the light guide can be improved. The curved surface of the reflecting plate is formed so as to be uniform on the light diffusing plate surface, and the material constituting the reflecting plate is selected. The material constituting the reflector is a material that efficiently reflects the reached light toward the light diffuser, for example, a foamed light reflector made of a foamed resin material having a total reflectance of 90% or more and a diffuse reflectance of 90% or more. Is used.

  In the light guide, the present invention is characterized in that a space is provided between the top portions of both sides of the reflecting plate and the light diffusing plate.

  By adopting the above configuration in the light guide, a part of the light emitted from the light emitting diode can reach the adjacent reflector, so that the light diffuser part facing the part where the light emitting diode is disposed is also light. Can be reached.

  In the light guide, the optical axis of the light emitting diode may have an angle of 90 degrees or more with respect to a vertical line of the light diffusion plate surface.

  As described above, since the optical axis of the light emitting diode has an angle of 90 degrees or more with respect to the vertical line of the light diffusion plate surface, extremely high brightness light does not reach the light diffusion plate. It is possible to prevent unevenness of light.

  In the light guide, the present invention is characterized in that a surface-mounted light emitting diode having a light irradiation angle of 90 degrees or more is used for the light emitting diode.

  As described above, by using a surface-mounted light emitting diode with a light irradiation angle of 90 degrees or more as the light emitting diode, light emitted from one surface-mounted light emitting diode with a light irradiation angle of 90 degrees or more is Since the light is reflected by a wide surface of the curved inner surface, uniform light can be emitted from the light diffusion plate surface with a small number of light emitting diodes.

  In the light guide, the present invention is characterized in that a folded portion is provided at the top of the one side where the light emitting diode of the reflector is disposed.

  Since the folded portion is provided at the top of one side of the reflecting plate on which the light emitting diode of the reflecting plate is arranged as described above, the light emitting diode placement portion can be reliably covered with the reflecting plate, so that the light diffusing plate surface Can emit uniform light. Furthermore, by inserting the other side where the light emitting diode of the reflector adjacent to the folded portion is not disposed, the reflector can be easily connected, assembled and maintained, and the space between the top of the reflector and the diffuser Can be reliably maintained.

  Further, the present invention is characterized in that one or a plurality of light guides are provided, and the irradiated portion is directly or indirectly illuminated as light emitted from the light diffusion plate of the light guide.

  As described above, the light emitted from the light diffusing plate of the light guide is illuminated directly or indirectly on the irradiated portion as illumination light, so that the irradiated portion is directly or indirectly irradiated with the irradiation light emitted from the uniform surface light source. Lighting can be realized.

  According to another aspect of the present invention, there is provided a display device including one or a plurality of light guides having the above-described configuration, and using light emitted from the light diffusion plate of the light guide as a surface light source.

  Since the light emitted from the light diffusion plate of the light guide is used as the surface light source of the display device as described above, a display device including a uniform surface light source can be realized.

  According to the first aspect of the present invention, since the reflecting plate is made of a thin plate formed in a curved shape, a light guide having a simple configuration and a light weight can be provided. Further, since the light emitting diodes need only be arranged near one side curved at 90 degrees or more with respect to the inner surface of the intermediate portion of the reflector, the number of light emitting diodes can be greatly reduced. Therefore, a light guide having a simple structure, light weight, low cost, and long life can be provided.

  According to the second aspect of the present invention, since the reflector plate having a configuration in which a plurality of reflectors made of thin plates are arranged adjacent to each other is configured, a light guide having a light diffusing plate having a large area can be simplified. It is possible to provide a light weight with a configuration. Further, since the light emitting diode only needs to be arranged near one side curved at 90 degrees or more with respect to the inner surface of the intermediate portion of each reflecting plate in the reflecting plate row, the light guide provided with the light diffusing plate having a wide area is used as the light emitting diode. Can be provided with a greatly reduced number. Therefore, it is possible to provide a light guide including a light diffusing plate having a simple structure, light weight, low cost, and long life.

  According to the third aspect of the present invention, since the space is provided between the top portion of the reflecting plate and the light diffusing plate, the light can reach the region of the adjacent reflecting plate or the light diffusing plate facing it. Therefore, a light guide that emits uniform light from the surface of the light diffusion plate with a small number of light emitting diodes can be provided at low cost.

  According to the invention of claim 4, since the optical axis of the light emitting diode has an angle of 90 degrees or more with respect to the vertical line of the light diffusion plate surface, light with extremely high brightness does not reach the light diffusion plate. It is possible to prevent the occurrence of unevenness of light on the light diffusion plate and to provide a light guide that emits uniform light from the surface of the light diffusion plate at a low cost.

  According to the invention described in claim 5, since the surface-mounted light emitting diode having a light irradiation angle of 90 degrees or more is used as the light emitting diode, a light guide device that emits uniform light from the light diffusion plate surface with a small number of light emitting diodes. Can be provided at low cost.

  According to the sixth aspect of the present invention, since the folded portion is provided at the top of one side where the light emitting diode of the reflecting plate is arranged, the light emitting diode arrangement portion can be reliably covered with the reflecting plate, and light diffusion is performed. A light guide that emits uniform light from the plate can be provided at low cost. Further, by inserting one side where the light emitting diode of the reflection plate adjacent to the folded portion is not disposed, the connection, assembly and maintenance of the reflection plate are facilitated, and between the tops of the reflection plates and the light diffusion plate. A light guide that can reliably maintain the space can be provided at low cost.

  According to the seventh aspect of the present invention, the light emitted from the light diffusing plate of the light guide is illuminated directly or indirectly on the irradiated portion as illumination light, so that the structure is simple, inexpensive, and has a long life. Alternatively, an indirect lighting device can be realized.

  According to the eighth aspect of the present invention, since the light emitted from the light diffusion plate of the light guide is used as the surface light source, the surface light source of the display device can be realized with a simple structure, low cost, and long life.

  Embodiments of the present invention will be described below with reference to the drawings. 3 to 5 are diagrams showing a configuration example of the light guide according to the present invention. FIG. 3 (a) is a plan view with the light diffusion plate removed, and FIG. 3 (b) is a sectional view (A in FIG. 3 (a)). 4 is a cross-sectional view of the reflector, and FIG. 5 is an AA enlarged cross-sectional view of FIG. The light guide 10 includes a case 11, a reflection plate 12, and a light diffusion plate 13. The case 11 has a rectangular planar shape, a bottomed structure with four side walls, and is entirely composed of a light shield. The reflecting plate 12 is made of a rectangular thin plate, and as shown in FIG. 4, one side 12a of both long sides is bent and bent at 90 degrees or more with respect to the inner surface (upper surface in the drawing) of the intermediate portion 12b, and the other side 12c. Is a configuration in which a curved surface 12f that reflects light on the entire inner surface is formed in a shape bent at 90 degrees or less. Further, a folded portion 12d formed by folding the end portion of the reflecting plate 12 is formed at the top of one side 12a which is bent at 90 degrees or more.

  A diode mounting board 15 is installed adjacent to one side 12a of the reflecting plate 12 bent at 90 degrees or more, and a plurality of light emitting diodes 14 are arranged and mounted on the diode mounting board 15 at a predetermined interval. . The light emitting portion of the light emitting diode 14 passes through the reflector 12 as shown in FIG. 6 and is exposed to the curved inner surface 12f. As shown in FIG. 6, a surface-mount type light-emitting diode 14 having a light irradiation angle α that emits a beam of expanded light L of 90 degrees or more (α ≧ 90 °) is used as the light-emitting diode 14. Further, the angle β of the optical axis Lx of the light emitting diode 14 with respect to the vertical line γ of the inner surface 13a (lower surface in the drawing) of the light diffusion plate 13 is 90 degrees or more (β ≧ 90 °).

  A part of the light L emitted from the light emitting part of the light emitting diode 14 directly reaches the inner surface 13a of the light diffusion plate 13, and a part thereof is irradiated to the curved inner surface 12f of the reflecting plate 12, and is reflected by the curved inner surface 12f. The light reaches the inner surface 13 a of the light diffusion plate 13. Here, the reflection plate 12 is configured so that the light directly reaching from the light-emitting diode 14 and the light reflected by the curved inner surface 12f of the reflection plate 12 are combined with the inner surface 13a of the light diffusion plate 13 so as to reach the entire surface uniformly. The material of the material to be selected is selected, and the shape of the curved inner surface 12f of the reflecting plate 12 is set. Thereby, the outer surface (upper surface in the figure) of the light diffusing plate 13 becomes a surface light source that emits uniform light. The material constituting the reflection plate is a material that can be easily formed into a curved shape with a thin plate and efficiently reflects the reached light toward the light diffusion plate. For example, the total reflection rate is 90% or more, and the diffuse reflection rate is 90%. A foamed light reflecting plate made of a foamed resin material of at least% is used. A space is formed between the tops of both long sides of the reflecting plate 12 and the inner surface of the light diffusing plate 13.

  As described above, by using the surface-mounted light-emitting diode 14 having a light irradiation angle α of 90 degrees or more (α ≧ 90 °) as the light-emitting diode 14, the light diffusing plate 13 of the light guide 10 can be formed with a small number of light-emitting diodes 14. Uniform light is emitted from the outer surface. Further, by setting the angle β of the optical axis Lx of the light emitting diode 14 with respect to the vertical line γ of the inner surface 13a of the light diffusion plate 13 to 90 degrees or more (β ≧ 90 °), light with extremely high luminance is emitted from the light diffusion plate 13. Since the inner surface 13a of the light diffusing plate 13 is not reached, unevenness of light does not occur on the outer surface of the light diffusing plate 13. Further, as described above, a space is formed between the tops of both long sides of the reflecting plate 12 and the inner surface of the light diffusing plate 13, so that the light reflected by the curved inner surface 12f of the reflecting plate 12 is light. The edges and corners of the diffusion plate 13 are uniformly reached, and the entire outer surface of the light diffusion plate 13 becomes a uniform surface light source.

  As described above, the light guide 10 is composed of the case 11, the thin curved reflector 12, the light diffusion plate 13, the diode mounting substrate 15, and the like, so that it has a very simple structure, and processing and assembly of the constituent members. Becomes easy. Moreover, since the whole becomes lightweight, it becomes possible to attach with a simple attachment member. In addition, in the case of the light guide 10 configured by disposing the single reflection plate 12 in the case 11 as described above, the folded portion 12d at the top of one side of the reflection plate 12 is not necessarily required. It may be removed.

  7 and 8 are diagrams showing a configuration example of the light guide according to the present invention. FIG. 7A is a plan view with the light diffusion plate removed, and FIG. 7B is a cross-sectional view (B in FIG. 7A). FIG. 8 is an enlarged cross-sectional view taken along the line BB in FIG. 7A. The light guide 20 includes a case 21, a plurality of (in the figure, four) reflection plates 22, and a single light diffusion plate 23. The case 21 has a rectangular flat surface, a bottomed structure and four side walls, and is entirely composed of a light shield. Each reflection plate 22 has the same configuration as the reflection plate 12 shown in FIG. 4, and has a side 22a, an intermediate portion 22b, and another side 22c as shown in FIG. 9, and a curved inner surface 22f that reflects light on the entire inner surface. Shape. Further, a folded portion 22d is formed at the top of one side 22a that is bent at 90 degrees or more. Between the adjacent reflecting plates 22 and 22, the other side 22c of the other reflecting plate 22 is inserted into the folded portion 22d of one side 22a of one reflecting plate 22, and a number of reflecting plates 22 are connected to form a reflecting plate array. It is composed. The curved inner surface 22 f of each reflector 11 in the reflector array is accommodated in the case 21 so as to face the opening of the case 21.

  A diode mounting board 25 is installed in the vicinity of one side 22a where the folded portion 22d of the reflecting plate 22 is formed, and one or a plurality of light emitting diodes 24 are arranged and mounted on the diode mounting board 25 at a predetermined interval. . The light emitting portion of the light emitting diode 24 passes through the reflecting plate 22 as shown in FIG. 9 and is exposed to the curved inner surface 22f. The light emitting diode 24 and the arrangement portion thereof are covered with one end 22a where the folded portion 22d of the reflecting plate 22 on which the light emitting diode is mounted is formed and the other end 22c where the folded portion 22d of the adjacent reflecting plate 22 is not formed. . As shown in FIG. 6, the light-emitting diode 24 is a surface-mounted light-emitting diode 24 that emits a beam of wide-angle light L and has a light irradiation angle of 90 degrees or more. It is the same as the vessel. A space G (see FIG. 8) is provided between the top of the side 22a of each reflecting plate 22 and the inner surface 23a of the light diffusing plate 23.

  A part of the light L emitted from the light emitting part of the light emitting diode 24 arranged adjacent to the one side 22a of each reflecting plate 22 directly reaches the inner surface 23a of the light diffusing plate 23, and a part of the light is reflected. The light that reaches the curved inner surface 22 f of the plate 22 and is reflected by the curved inner surface 22 f reaches the inner surface 23 a of the diffusion plate 23. A part of the emitted light L reaches the inner surface 23 a of the light diffusion plate 23 through the adjacent reflection plate 22. Here, the shape of the curved inner surface 22f of each reflecting plate 22 is set so that the light uniformly reaches the inner surface 23a of the light diffusing plate 23, and the material constituting each reflecting plate 22 is selected. Thereby, the outer surface (upper surface in the figure) of the light diffusion plate 23 having a large area becomes a surface light source that emits uniform light. In addition, since a space G is provided between the top of the side 22a where the folded portion 22d of each reflecting plate 22 is formed and the inner surface 23a of the light diffusing plate 23, the adjacent reflecting plate 22 and the light facing it. Since light can reach the area of the inner surface 23 a of the diffusion plate 23, uniform light is emitted from the outer surface of the light diffusion plate 23. Further, as the material constituting the reflection plate 22, like the reflection plate 12, it is easy to form a thin plate in a curved shape, and reflects the reached light toward the light diffusion plate 23 efficiently. A foamed light reflector made of a foamed resin material having a reflectance of 90% or more and a diffuse reflectance of 90% or more is used.

  As described above, the light guide 20 is composed of the case 21, the plurality of thin curved reflectors 22, the light diffusion plate 23, the plurality of diode mounting boards 25, and the like. In spite of a large (outside area of the light diffusing plate 23), the structure becomes very simple, and the processing and assembly of the constituent members becomes easy. Moreover, since the whole becomes lightweight, it becomes possible to attach with a simple attachment member.

  In the above-described embodiment, one side 12a and 22a forming the folded portions 12d and 22d of the reflectors 12 and 22 is curved by 90 degrees or more with respect to the inner surfaces of the intermediate portions 12b and 22b. The surface of the sides 12a and 22a where the light emitting diode 14 is exposed, that is, the surface of the curved inner surfaces 12f and 22f where the light emitting diode 14 is exposed is not seen from the direction of the light diffusion plates 13 and 23. , 23, the reflection area inside the light guide 10 is improved by reducing the arrangement area of the light emitting diodes 14 as viewed from the direction 23. That is, in order to improve the reflection characteristics inside the light guide 10, the inner surfaces (the inner surface 12 g in FIG. 5 and the inner surface 22 g in FIG. 9) in the vicinity of the sides 12 a and 22 a where the light emitting diode 14 is exposed are the light diffusion plate 13. The sides 12a and 22a are curved with respect to the inner surfaces of the intermediate portions 12b and 22b so that they cannot be seen from the direction of.

  In FIG. 10, the light guide 10 or the light guide 20 is arranged on the ceiling surface 31 or the wall surface 32 with the light diffusion plate 13 or the light diffusion plate 23 facing indoors, and is emitted from the light diffusion plate 13 or the light diffusion plate 23. It is a figure which shows the schematic example as a direct illuminating device which illuminates the room with light. Here, in particular, if the light guide 20 having a configuration in which a plurality of reflecting plates 22 are arranged adjacent to each other is used, it is possible to illuminate the room with soft light emitted from a light diffusion plate 23 having a large area. Further, by providing a pattern such as a photograph on the surface of the light diffusing plate 23, the side illumination decorated with these patterns can be performed. Although not shown, the ceiling surface 31 and the wall surface 32 are irradiated with light emitted from the light diffusion plate 13 or the light diffusion plate 23 of the light guide 10 or the light guide 20, and the ceiling surface 31 or the wall surface 32. It is good also as an indirect lighting device which illuminates the room with the light reflected by the.

  11A and 11B are diagrams illustrating an example in which the light guide 10 or the light guide 20 is used as a display device for a signboard. FIG. 11A is a front view and FIG. 11B is a side view. As shown in the figure, by attaching a signboard 33 made of a translucent material on which characters and pictures are drawn, to the outer surface of the light diffusing plate 13 or the light diffusing plate 23 of the light guide 10 or the light guide 20, the light diffusing plate 13 or the light and the pattern drawn on the signboard by the light emitted from the light diffusion plate 23 are displayed. Further, since the light guide 20 having the light diffusion plate 23 having a large area can be lightened, it can be easily attached to the wall of a building or a building. In addition, the structure can be simplified by drawing characters and designs directly on the light diffusion plate 13 or 23 and integrating them with the signboard 33.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. For example, the light guide according to the present invention can be used in a wide range of fields, such as buildings, outer walls of buildings, and illumination and decoration of various events.

It is a figure which shows the schematic structural example of the conventional surface light source. It is a figure which shows the schematic structural example of the conventional surface light source. It is a figure which shows the schematic structural example of the light guide which concerns on this invention. It is sectional drawing which shows the structural example of the reflecting plate used for the light guide which concerns on this invention. It is an AA expanded sectional view of Drawing 3 (a) of a light guide concerning the present invention. It is the schematic which shows the radiation state of the light beam of a surface mount type light emitting diode. It is a figure which shows the schematic structural example of the light guide which concerns on this invention. It is a BB expanded sectional view of Drawing 7 (a) of a light guide concerning the present invention. It is sectional drawing which shows the structural example of the reflecting plate used for the light guide which concerns on this invention. It is a figure which shows the structural example of the illuminating device using the light guide which concerns on this invention. It is a figure which shows the structural example of the display apparatus (signboard) using the light guide which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light guide 11 Case 12 Reflector 13 Light diffuser 14 Light emitting diode 15 Diode mounting board 20 Light guide 21 Case 22 Reflector 23 Light diffuser 24 Light emitting diode 25 Diode mounting board 31 Ceiling surface 32 Wall 33 Signboard

Claims (8)

A reflecting plate made of a thin plate having both sides curved with respect to the intermediate portion to form a rising curved surface, and a light diffusing plate arranged to face the inner surface of the intermediate portion of the reflecting plate,
One side of the two sides of the reflector is curved at 90 degrees or more with respect to the inner surface of the intermediate portion, the other side is curved at 90 degrees or less, and emits one or more light emitting diodes near the one side. At least a part of the light is reflected by the curved inner surface of the reflector and reaches the light diffusing plate, and the light reflected by the curved inner surface of the reflector reaches the light diffusing plate surface. A light guide characterized by that. A reflecting plate array having a configuration in which a plurality of reflecting plates made of thin plates with both sides curved with respect to the intermediate portion to form a rising curved surface are arranged adjacent to each other, and an inner surface of the intermediate portion of each reflecting plate in the reflecting plate row With light diffusing plates arranged facing each other,
One side of the two sides of each of the reflectors in the reflector row is curved at 90 degrees or more with respect to the inner surface of the intermediate portion, the other side is curved at 90 degrees or less, and the singular or plural are located near the one side. The light emitting diode is arranged such that at least part of the light emitted from the light-emitting diode is reflected by the curved inner surface of the reflecting plate and reaches the light diffusion plate, and the light reflected by the curved inner surface of the reflecting plate array is the light. A light guide characterized by reaching the diffusion plate surface. The light guide according to claim 1 or 2,
A light guide, wherein a space is provided between the top portions of both sides of the reflection plate and the light diffusion plate. The light guide according to claim 1 or 2,
The light guide according to claim 1, wherein an optical axis of the light emitting diode has an angle of 90 degrees or more with respect to a vertical line of the light diffusion plate surface. The light guide according to claim 1 or 2,
A light guide using a surface-mounted light emitting diode having a light irradiation angle of 90 degrees or more as the light emitting diode. The light guide according to claim 1 or 2,
A light guide, wherein a folded portion is provided at the top of the one side where the light emitting diode of the reflecting plate is disposed.   One or a plurality of light guides according to any one of claims 1 to 6 are provided, and light emitted from the light diffusion plate of the light guides is directly or indirectly applied to an irradiated portion as illumination light. A lighting device characterized by illuminating.   A display comprising one or more light guides according to any one of claims 1 to 6, wherein light emitted from the light diffusion plate of the light guide is used as a surface light source. apparatus.

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