JP2014032827A - Illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device which can radiate the heat generated in a light source while securing the safety of a user.SOLUTION: In an illumination device 10, a cabinet 23 comprises a heat radiation part 23a and a resin part 23b, which are mutually separate members. The heat radiation part 23a forms the top face of the cabinet 23 adjacent to a side face part 23d where light from a light source module 21 exits. The resin part 23b is composed of a material low in thermal conductivity than the heat radiation part 23a, and forms the bottom face of the cabinet 23 facing the top face of the cabinet 23.

Description

  The present invention relates to an illumination device in which light from a light source is emitted from a side surface of a housing.

  In recent years, lighting devices are required to have energy saving performance, light amount adjustment function, light color adjustment function, and design. For this reason, the light source of the illuminating device is being replaced by LED (Light Emitting Diode) instead of the conventional filament type light bulb and fluorescent lamp.

  For example, Patent Literature 1 discloses an illumination stand (lighting fixture) that uses a light emitting element such as an LED as a light source. The illumination stand described in Patent Document 1 includes a pedestal portion, a support column erected from the pedestal portion, and an illumination unit provided on the upper portion (end portion) of the support column. The illumination unit has a frame (housing) fixed to the support column, and a circuit board on which the light emitting element is mounted is installed inside the frame.

JP 2007-59285 A (published March 8, 2007)

  Although the light emitting element generates heat when the lighting fixture is turned on, Patent Document 1 does not describe any heat countermeasures for the light emitting element. Furthermore, the specific configuration of the frame on which the light emitting element is mounted is not disclosed in Patent Document 1.

  Therefore, for example, as a countermeasure against heat of the light emitting element in Patent Document 1, it is conceivable that the frame on which the light emitting element is installed is made of metal. Thereby, the heat generated in the light emitting element is conducted to the entire frame and dissipated.

  However, in the case of the illumination stand described in Patent Document 1, the upper surface of the frame is a part that the user touches when adjusting the irradiation range. For this reason, if the heat is radiated through the frame, the portion that is easy for the user to touch is heated, and there is a problem in user safety.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide an illumination device that can dissipate heat generated by a light source while ensuring the safety of a user.

  In order to solve the above-described problem, an illumination device according to the present invention includes a light source and a housing in which the light source is installed, and the light device emits light from the first side surface of the housing. The housing includes a first housing portion on which the light source is arranged and forms a first surface adjacent to the first side surface portion, and a material having a lower thermal conductivity than the first housing portion. And a second housing part forming a second surface opposite to the first surface.

  According to said structure, the housing is comprised from the 1st housing part and the 2nd housing part, and the light source is installed in the 1st housing part. Thereby, the heat generated by the light source is conducted to the first housing part and is radiated through the first housing part. On the other hand, since the second casing part has an overwhelmingly lower thermal conductivity than the first casing part, heat is not easily transmitted from the first casing part to the second casing part. That is, when heat is generated by the light source, the temperature of the first housing part increases, while the temperature of the second housing part does not change or only slightly increases. Therefore, the heat generated by the light source can be actively dissipated through the first housing part.

  Furthermore, according to said structure, since the housing is comprised by the separate body divided into the 1st housing part and the 2nd housing part, it can arrange | position a 2nd housing part in the part which a user is easy to touch. it can. Thereby, even if the heat is generated by the light source, the portion that is easy to be touched by the user becomes the second housing portion having a temperature much lower than that of the first housing portion. For this reason, even if a user touches the 2nd housing part, there is no problem in a user's safety aspect.

  Therefore, according to said structure, the heat | fever generated with the light source can be thermally radiated, ensuring a user's safety.

  In the lighting device according to the present invention, how to arrange the metal portion and the resin portion of the housing may be set according to the use of the lighting device. That is, a portion that is more easily touched by the user may be used as the resin portion depending on the application of the lighting device. As a result, the portion that is easy for the user to touch becomes a resin portion having a temperature much lower than that of the metal portion even when heat is generated by the light source. Therefore, it is possible to provide a lighting device having a high heat dissipation effect while ensuring user safety.

  Note that “the light from the light source is emitted from the side surface of the housing” means, for example, a configuration in which the light from the light source directly emits from the side surface of the housing, or the light from the light source is reflected in the housing. Thus, a configuration in which the reflected light is emitted from the side surface of the housing is included.

  In the lighting device according to the aspect of the invention, it is preferable that the casing includes a heat insulating member between the first casing portion and the second casing portion.

  According to said structure, since the heat insulation member is provided between the said 1st housing | casing part and the 2nd housing | casing part, the heat conduction from a 1st housing | casing part to a 2nd housing | casing part is suppressed. Therefore, the temperature rise of the second housing part can be reliably suppressed.

  In the illuminating device of the present invention, the first housing part includes a light source installation part in which the light source is installed, and the heat insulating member is provided apart from at least one of the light source installation part and the light source. It is preferable.

  According to said structure, since a light source is installed in a light source installation part, a light source installation part becomes a part which absorbs the heat | fever of a light source and generates heat. The heat insulating member is provided so as to avoid such a light source installation portion which is a heat generating portion of the first casing portion. For this reason, since a light source installation part and a heat insulation member become non-contact, it becomes difficult to transmit heat directly from a light source installation part to a heat insulation member. Moreover, the heat insulating member also functions as a spacer for providing the second casing portion and the first casing portion (particularly, the light source installation portion) apart from each other. For this reason, conduction of heat from the first housing part to the second housing part is suppressed. Therefore, the temperature rise of the resin part can be reliably suppressed.

  In the illuminating device of this invention, it is preferable to provide the light guide member which the light radiate | emitted from the side part of the said housing enters, light-guides the incident light inside, and radiate | emits it.

  According to said structure, since the light guide member is provided in the side part of the housing, it becomes the structure which the light guide member protruded from the side part of the housing. Thereby, a light guide member becomes an obstruction when a user tries to touch a 1st housing part. Therefore, it can prevent more reliably that a user touches a 1st housing part.

  In the lighting device according to the aspect of the invention, it is preferable that the second casing portion forms a second side surface portion adjacent to the first side surface portion from which light from the light source is emitted.

  According to said structure, the 2nd housing | casing part forms the 2nd side part adjacent to the 1st side part from which the light from a light source radiate | emits. In other words, the second housing part forms a side surface on which the light guide member of the housing is not installed. For this reason, since the 1st housing | casing part with comparatively high temperature does not form the side surface in which the light guide member of a housing is not installed, even if a user touches the side surface in which a light guide member is not installed, it is safe because it is not high temperature.

  In the lighting device according to the aspect of the invention, it is preferable that a suspension member for suspending the housing is provided, and the second surface is a lower surface of the housing suspended by the suspension member.

  According to said structure, the housing is suspended by the suspension member. Therefore, it is possible to provide a pendant illumination device (pendant light) that can dissipate heat generated by the light source while ensuring the safety of the user.

  As described above, according to the illumination device of the present invention, it is possible to provide an illumination device that can dissipate the heat generated by the light source while ensuring the safety of the user.

It is a perspective view of the illuminating device concerning one Embodiment of this invention. It is a perspective view of the illumination part in the said illuminating device. It is a perspective view which shows the back surface of the thermal radiation part in the said illuminating device. It is a side view of the longitudinal direction of the said thermal radiation part. It is the perspective view which decomposed | disassembled the housing of the said illuminating device. It is sectional drawing which shows the relationship between the entrance plane of the light-guide plate in the said illuminating device, and the light source installation surface of a light source installation part. It is a figure which shows the path | route of the light which guides the light-guide plate from which a shape differs in the said illuminating device, (a) is sectional drawing which shows the path | route of the light which injected into the flat light-guide plate, (b) was curved It is sectional drawing which shows the path | route of the light which injected into the light-guide plate. It is a figure which shows the relationship between the shape of the light-guide plate in the said illuminating device, and the irradiation pattern from an output surface. It is a perspective view which shows the positioning method of the light-guide plate with respect to a thermal radiation part. It is an enlarged view of the positioning part shown with the wavy line of FIG. It is sectional drawing which shows the structure by which the reflection sheet was provided between the light source module and the entrance plane of the light-guide plate. It is a perspective view of the illumination part in the illuminating device concerning another one Embodiment of this invention. It is a perspective view of the thermal radiation part in the illumination part of the said illuminating device. It is a figure which shows the housing inside in the illumination part of the said illuminating device. It is a perspective view which shows the bottom part of the thermal radiation part in the illumination part of the said illuminating device. It is sectional drawing which shows the structure by which the reflective sheet was provided between the light source module in the said illuminating device, and the entrance plane of a light-guide plate. It is a perspective view which shows the positioning method of the light-guide plate with respect to the thermal radiation part in the said illuminating device. It is a figure which shows the path | route of the light which guides the inside of the light-guide plate in the said illuminating device.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a suspended illumination device will be described as an example of the illumination device according to the present invention. However, the lighting device according to the present invention is not limited to the hanging type lighting device, but includes various types such as a ceiling light directly attached to a ceiling surface, a lighting device embedded in a ceiling or a wall surface, and a lighting stand used on a desk. It can be applied to other lighting applications.

  In the following description, for convenience, the installation surface side of the lighting device will be described as the upper part (upper), and the irradiation surface side such as a desk surface or floor will be described as the lower part (lower). In the present specification, unless otherwise specified, “vertical” and “parallel” are not limited to completely “vertical” and completely “parallel”, but are substantially “vertical” and substantially “parallel”. Is also included. That is, being substantially vertical and substantially parallel is also a category of “vertical” and “parallel”. Moreover, in each figure, the same referential mark shall represent the same part or an equivalent part (same function), and detailed description is not repeated.

[Embodiment 1]
(Configuration of lighting device 10)
Based on FIG. 1, the illuminating device which concerns on Embodiment 1 is demonstrated. FIG. 1 is a perspective view of a lighting device 10 according to an embodiment of the present invention.

  The lighting device 10 is a hanging type lighting device (so-called pendant light) that is hung from an installation surface such as a ceiling. The illuminating device 10 is connected to the fixing unit 1 fixed to the installation surface, the illuminating unit 2 provided with the light source, the fixing unit 1 and the illuminating unit 2, and two wires 3a ( A suspension member) and a power supply line (feed line) 3b.

  The fixing unit 1 is an instrument body in the lighting device 10. The fixing unit 1 includes a one-touch adapter (not shown), and the one-touch adapter is connected to a rosette attached to the ceiling. Thereby, the fixing | fixed part 1 is mounted | worn so that attachment or detachment is possible. In addition, although not shown, the fixing unit 1 includes a power supply board and a lighting control unit in order to control lighting of the light source of the illumination unit 2.

  One end of each of the wire 3a and the power supply line 3b is connected to the fixed unit 1 and the other end is connected to the illumination unit 2, and the illumination unit 2 is horizontally arranged with two wires 3a (on an irradiation surface such as a table or floor) It is suspended in parallel. The power supply line 3 b has a function of supplying power to the illumination unit 2. Thereby, electric power is supplied to the illumination part 2 from the fixing | fixed part 1 via the rosette etc. which were provided in the installation surface. In this embodiment, the wire 3a and the power supply line 3b are provided independently. However, the wire 3a and the power supply line 3b may be bundled into one. Further, the number of wires 3 and power supply lines 3b is not limited and can be set arbitrarily.

  The illuminating unit 2 includes two light source modules 21 as light sources, two light guide plates 22 (light guide members) provided corresponding to the light source modules 21, and a housing that holds the light source modules 21 and the light guide plates 22. 23. The light source module 21 is installed inside the housing 23.

  Specifically, the light source module 21 has a configuration in which a plurality of LED chips electrically connected to the LED substrate are mounted, and is simply shown in the drawing. In the present embodiment, the LED substrate and the LED chip are collectively referred to as a light source module (light source). Each light source module 21 is installed in the housing 23 so that light is emitted from two side surface portions 23d (first side surface portions) facing each other in the housing 23.

  In addition, the illuminating device 10 of this embodiment is a structure which the light from the light source module 21 radiate | emits directly from the side part 23d of the housing 23. FIG. However, the configuration for emitting the light of the light source module 21 from the side surface portion 23d of the housing 23 is not limited to this configuration. For example, the light from the light source module 21 is reflected in the housing 23 and the reflected light is reflected on the housing 23. The structure etc. which radiate | emit from the side part 23d may be sufficient.

  The light guide plate 22 guides the light emitted from the light source module 21 to the inside and emits it. The light guide plate 22 protrudes to the outside from both side surface portions 23d of the same housing 23 in which the light source module 21 is disposed. The light guide plate 22 is made of a transparent material such as an acrylic resin, a polycarbonate resin, polystyrene, or glass. In the present embodiment, the light guide plate 22 has a lower surface 22b and an upper surface 22c, which are emission surfaces, which will be described later, curved toward an irradiation surface such as a desk surface or a floor, but may have a flat plate shape.

  An incident surface 22 a that is an end surface of the light guide plate 22 on which light from the light source module 21 is incident is disposed to face the light source module 21. Light that has entered the light guide plate 22 through the incident surface 22a propagates through the light guide plate 22 while repeating total reflection. A part of the light propagating through the light guide plate 22 is emitted from the lower surface 22b, which is the emission surface of the light guide plate 22 facing the irradiation surface, and the upper surface 22c of the light guide plate 22 by the light extraction means provided in the light guide plate 22. The

  The light extraction means includes, for example, a light diffusing material dispersed in the light guide plate 22, a concavo-convex structure formed on the lower surface 22b or the upper surface 22c, which is the exit surface of the light guide plate 22, and a diffusion printed on the exit surface. Examples include patterns. By providing such light extraction means, the optical path of the light guided through the light guide plate 22 can be changed and emitted from the lower surface 22b or the upper surface 22c of the light guide plate 22. In the present embodiment, light is emitted from the lower surface 22b and the upper surface 22c of the light guide plate 22, but the light may be emitted from only one of the surfaces.

  Moreover, in this embodiment, the outer edge part 22d which consists of outer edge part 22d1, 22d2, 22d3 which is a surface formed in the thickness direction of the light-guide plate 22 of the light-guide plate 22 is an inclined surface. That is, the outer edge portion 22d1 located opposite to the incident surface 22a and the outer edge portions 22d2 and 22d3 extending in the direction of light emission from the light source module 21 are tapered surfaces. In addition, although the inclination angles of the outer edge portions 22d1 to 22d3 are formed to be substantially the same, different inclination angles may be used. The inclination angle of the outer edge portion 22d may be arbitrarily set according to the direction of reflection by the outer edge portion 22d.

  In the illuminating device 10, since the light that has reached the outer edge portion 22d is emitted from the lower surface 22b that is the emission surface, the angle formed between the lower surface 22b and the outer edge portion 22d is an acute angle. The outer edge portion 22d is coated with a reflective film that reflects light. Thereby, the light reflected by the outer edge portion 22d is emitted in the direction of the irradiation surface. Therefore, it is possible to improve the illuminance of the irradiated surface by suppressing light that escapes from the outer edge portion 22d in a direction substantially parallel to the irradiated surface such as the floor surface or the desk surface. Thus, the outer edge portion 22d can be said to be a reflective surface that reflects the light guided inside the light guide plate 22 and emits it from the lower surface 22b.

  The outer edge 22d (inclined surface) may not be coated with a reflective film that reflects light. In this case, since the outer edge 22d is inclined with respect to the lower surface 22b, a part of the light incident on the outer edge can be totally reflected in the direction of the lower surface 22b and emitted from the lower surface 22b. However, since the light reflection efficiency is improved by applying the reflective film to the outer edge portion 22d, it is advantageous in that the illuminance on the irradiated surface can be improved.

  The outer edge portion 22d can be formed of a plane, a curved surface, or a surface obtained by combining a plane and a curved surface. By making the inclined surface flat, the processing of the light guide plate 22 becomes easy, and the lighting device 10 can be provided with high mass productivity and low cost. Moreover, the light extraction efficiency and the illumination intensity of the irradiated surface can be improved by making the inclined surface a curved surface.

  In the illumination device 10, the light guide plate 22 emits light when the light source module 21 is turned on, and the light guide plate 22 is kept transparent when the light source module 21 is not turned on.

  The housing 23 holds the light guide plate 22 while the light source module 21 is installed. The housing 23 is configured by combining a heat radiating portion 23a as a first housing portion and a resin portion 23b as a second housing portion having a lower thermal conductivity than the heat radiating portion 23a. That is, the housing 23 includes a heat radiating portion 23a and a resin portion 23b, which are separate members. As will be described later, the heat radiating portion 23a is provided on the fixed portion 1 side (ceiling side) and constitutes an upper surface as a first surface of the housing 23 (see FIG. 2). Further, as will be described later, the resin portion 23b is provided opposite to the fixing portion 1 with respect to the heat radiating portion 23a, and constitutes a lower surface which is a surface on the irradiation surface side of the housing 23 (see FIG. 5). ). The lower surface is a second surface facing the upper surface of the housing 23. Details of the housing 23 will be described later.

  As described above, the illumination device 10 of the present embodiment is configured to emit the light emitted from the side surface portion 23 d of the housing 23 through the light guide plate 22. Moreover, the housing 23 is comprised from the thermal radiation part 23a and the resin part 23b, and the light source module 21 is installed in the thermal radiation part 23a. Thereby, the heat generated in the light source module 21 is conducted to the heat radiating portion 23a and is radiated through the heat radiating portion 23a. On the other hand, since the resin part 23b has an overwhelmingly lower thermal conductivity than the heat radiating part 23a, heat is hardly transmitted from the heat radiating part 23a to the resin part 23b. That is, when heat is generated in the light source module 21, the temperature of the heat radiating portion 23a is increased, while the temperature of the resin portion 23b is not changed or only slightly increased. Therefore, the heat generated in the light source module 21 can be actively radiated through the heat radiating portion 23a.

  Furthermore, in the illuminating device 10, since the housing 23 is comprised by the separate body divided into the thermal radiation part 23a and the resin part 23b, the resin part 23b can be arrange | positioned in the part which a user can touch easily. The illumination device 10 is a pendant light that irradiates a table or a floor. Therefore, the user can easily touch the lower surface, which is the surface on the irradiation surface side of the housing 23, and the resin portion 23b is disposed on the lower surface side. Thereby, even if heat is generated in the light source module 21, the portion that is easy for the user to touch becomes the resin portion 23b having a much lower temperature than the heat radiating portion 23a. For this reason, even if a user touches the resin part 23b, there is no problem in a user's safety aspect.

  Therefore, according to the illuminating device 10, the heat generated in the light source module 21 can be radiated while ensuring the safety of the user.

  Furthermore, in the illuminating device 10, the light guide plate 22 is provided on the side surface portion of the housing 23, so that the light guide plate 22 protrudes from the side surface portion of the housing 23. Thereby, the light-guide plate 22 becomes an obstruction when a user tries to touch the thermal radiation part 23a. Therefore, it is possible to make it difficult for the user to touch the heat radiating portion 23a.

  In addition, the light guide plate 22 is also made of an acrylic resin or the like that has an overwhelmingly lower thermal conductivity than the heat radiating portion 23a. For this reason, heat is not easily transmitted from the heat radiating portion 23a to the light guide plate 22 or from the light guide plate 22 to the resin portion 23b. For this reason, even if the user touches the light guide plate 22, there is no problem in terms of user safety. Therefore, user safety can be improved.

  Moreover, as for the illuminating device 10 of this embodiment, the housing 23 is suspended by the wire 3a. Accordingly, it is possible to provide a pendant illumination device (pendant light) that can dissipate the heat generated in the light source module 21 while ensuring the safety of the user.

(Configuration of the housing 23)
Based on FIGS. 2-5, the housing 23 is demonstrated in detail. FIG. 2 is a perspective view of the illumination unit 2 in the illumination device 10.

  As shown in FIG. 2, the heat radiating portion 23a is provided on the fixed portion 1 side (ceiling side) and constitutes an upper surface 23a 'of the housing 23 as a first surface. An upper surface 23a 'of the housing 23 is a surface of the housing 23 opposite to the irradiation surface such as a table or a floor. The upper surface of the housing 23 (the top surface of the heat radiation part 23a) is substantially rectangular. A screw 32, an adjustment member 31a, a cable fixing portion 31b, an adjustment member 31a, and a screw 32 are provided in this order along the longitudinal direction on the top surface of the heat radiating portion 23a. The two adjusting members 31a adjust the length of each wire 3a, and fix the wire 3a with the adjusted length. The cable fixing portion 31b is provided between the two adjustment members 31a, that is, at the center portion of the heat dissipation portion 23a, and fixes the power supply line 3b. The two screws 32 are fixing members that are provided outside the adjustment members 31a and fix the heat radiating portion 23a and the resin portion 23b.

  FIG. 3 is a perspective view showing the back surface of the heat radiating portion 23a (inside the housing 23). 4 is a side view in the longitudinal direction of the heat dissipating part 23a of FIG.

  As shown in FIG. 3, two light source installation parts 24 on which the light source modules 21 are installed are erected along the longitudinal direction on the back surface of the heat radiating part 23 a. Each light source module 21 is installed on the light source installation surface 24a which is the outer surface of the light source installation unit 24 (that is, the surface opposite to the surface where the light source installation units 24 face each other). Thereby, each light source module 21 radiate | emits light toward the outer side from the side part 23d of the housing 23 in the mutually reverse direction. In addition, in this embodiment, although the light source module is directly attached to the light source installation surface 24a of the thermal radiation part 23a, you may attach indirectly through a heat conductive sheet etc.

  The lighting device 10 of the present embodiment includes a light guide plate 22, and the light guide plate 22 is held by a housing 23. For this reason, a light guide plate holding portion 25 that holds the light guide plate 22 is formed in the heat radiating portion 23a. The light guide plate holding part 25 has a support surface 25a that supports the light guide plate 22 formed along the longitudinal direction of the heat radiating part 23a. The height of the support surface 25 a is such that the center position in the thickness direction of the light incident surface 22 a of the light guide plate 22 substantially coincides with the center position of the LED chip that is the light source in the light source module 21. In the present embodiment, the heat radiating portion 23a is formed by molding.

  When the heat radiating portion 23a is formed by molding, the shape of the heat radiating portion 23a is reproduced with high accuracy, and the height of the support surface 25a is also uniform. For this reason, as shown in FIG. 4, the support surface 25a becomes flush (flat). As a result, the light guide plate holding unit 25 can stably hold the light guide plate 22 at a fixed position. Further, the alignment (opposite relationship) between the light source module 21 and the incident surface 22a of the light guide plate 22 can be maintained with high accuracy. That is, the light guide plate holding unit 25 can hold the light guide plate 22 so that the incident surface 22 a of the light guide plate 22 is perpendicular to the optical axis of the light source module 21. Thereby, the emitted light from the light source module 21 efficiently enters the light guide plate 22. Therefore, the incident efficiency to the light guide plate 22 can be increased.

  The heat dissipating part 23a is not particularly limited as long as it has a high thermal conductivity, but is preferably a metal or ceramic having a high thermal conductivity. The heat radiating part 23a is preferably made of aluminum, for example. Moreover, the surface of the thermal radiation part 23a may be given white coating, for example. Thereby, the radiation effect by the thermal radiation part 23a can be heightened by radiation of white paint.

  On the other hand, the resin part 23b should just be formed from the material whose heat conductivity is lower than the thermal radiation part 23a. The resin constituting the resin portion 23b is not particularly limited, and various resins such as an epoxy resin and a polyimide resin can be applied. The resin constituting the resin portion 23b is preferably, for example, a polycarbonate resin, an ABS resin, an acrylic resin, or the like. The resin portion 23b may contain various additives in order to reduce the thermal conductivity. In the present embodiment, the resin portion 23b is made of a resin having a thermal conductivity lower than that of the heat radiating portion 23a. However, the resin portion 23b may be formed of ceramics having a thermal conductivity lower than that of the heat radiating portion 23a.

  FIG. 5 is an exploded perspective view of the housing 23. As shown in FIG. 5, in the lighting device 10, the light guide plate 22 is not provided from the side surface 23 c in the short direction of the housing 23. That is, the side surface 23c is a non-emission area where light from the light source module 21 is not emitted. The resin portion 23b is provided opposite to the fixing portion 1 with respect to the heat radiating portion 23a, and forms at least a lower surface 23b ′ of the housing 23 (a second surface facing the upper surface 23a ′ of the housing 23). That's fine. The lower surface 23b 'of the housing 23 is a surface facing the irradiation surface of the housing 23 such as a table or a floor. In the present embodiment, the resin portion 23b also forms a side surface portion 23d 'adjacent to the side surface portion 23d of the housing 23 from which the 23d light from the light source module 21 is emitted. In other words, the resin portion 23b is integrally formed from the lower surface 23b 'of the housing 23 to the side surface 23c of the housing 23 where the light guide plate 22 is not installed. That is, the resin portion 23b forms a side surface 23c on which the light guide plate 22 of the housing 23 is not installed. For this reason, since the heat radiating part 23a having a relatively high temperature does not form the side surface 23c, even if the user touches the side surface 23c on which the light guide plate 22 is not installed, it is safe because it is not high temperature.

  Furthermore, on the back surface (surface on the heat radiating portion 23a side) of the resin portion 23b, in order to fix the heat radiating portion 23a and the resin portion 23b, two projecting portions 26 extending toward the heat radiating portion 23a are provided. A screw hole 26 a is formed in the center of the protrusion 26 in the length direction. The screw 32 provided on the upper surface of the heat radiating portion 23a is inserted into the screw hole 26a (see FIG. 2). Thereby, the heat radiating part 23 a and the resin part 23 b are fixed by the screws 32. It is desirable that the length of the protrusion 26 of the resin portion 23b is such that the portion of the resin portion 23b where the protrusion 26 is not formed and the heat radiating portion 23a are not in contact with each other. Thereby, in parts other than the projection part 26, the thermal radiation part 23a and the resin part 23b are spaced apart and provided. That is, since the heat radiating part 23a and the resin part 23b are only in point contact, the contact area between the heat radiating part 23a and the resin part 23b becomes extremely narrow. Therefore, heat conduction from the heat radiation part 23a to the resin part 23b can be minimized.

  In addition, in the illuminating device 10, the screw 32 is fastened on the upper surface (installation surface side) of the heat radiating part 23a, and is not fastened on the resin part 23b side. That is, the screw 32 penetrates the heat insulating member 4 described later from the upper surface of the heat radiating portion 23a and is fastened to the protruding portion 26 of the resin portion 23b. If the screw 32 is fastened to the heat dissipation part 23a on the lower surface (irradiation surface side) of the resin portion 23b, the head of the screw 32 comes into contact with the lower surface of the resin portion 23b. As a result, the heat of the heat radiating part 23a is easily transmitted to the resin part 23b through the head of the screw 32. Furthermore, since the lower surface of the resin portion 23b is a portion that can be easily seen by the user, the appearance also deteriorates. Therefore, it is preferable that the screw 32 is fastened on the upper surface of the heat radiating part 23a.

(Insulation member 4)
Moreover, as shown in FIG. 5, the illuminating device 10 is equipped with the plate-shaped heat insulation member 4 between the thermal radiation part 23a and the resin part 23b. That is, the heat insulating member 4 is provided in the heat conduction path from the heat radiating portion 23a to the resin portion 23b. Specifically, the heat insulating member 4 covers substantially the entire back surface of the heat radiating portion 23a. Screws 41 are provided at four corners of the heat insulating member 4, and the heat radiating portion 23 a and the heat insulating member 4 are fastened by these screws 41, and the light guide plate 22 is sandwiched between the heat radiating portion 23 a and the heat insulating member 4. The Thereby, the light guide plate 22 is held by the housing 23 (fixed to the heat radiating portion 23a). Since the light guide plate 22 is disposed between the heat radiating portion 23 a and the heat insulating member 4, the heat radiating portion 23 a and the heat insulating member 4 are only in contact via screws 41. For this reason, the contact area of the thermal radiation part 23a and the heat insulation member 4 becomes extremely narrow. Therefore, the heat conduction from the heat radiation part 23a to the heat insulating member 4 can be minimized.

  The material of the heat insulating member 4 is not particularly limited as long as it has a function of preventing heat conduction from the heat radiating portion 23a to the resin portion 23b. For example, the heat insulating member 4 may be made of metal or resin. Thereby, since the heat insulation member 4 is provided between the thermal radiation part 23a and the resin part 23b, the heat conduction from the thermal radiation part 23a to the resin part 23b is suppressed. Therefore, the temperature rise of the resin part 23b can be reliably suppressed.

  In the case of a pendant light that uses the light guide plate 22 as in the lighting device 10 of the present embodiment, since the housing 23 needs to support the large light guide plate 22, the heat insulating member 4 may be made of metal. preferable. Thereby, holding | maintenance of the light-guide plate 22 by the housing 23 can be reinforced. On the other hand, if the heat insulating member 4 is made of resin, the heat conductivity of the heat insulating member 4 is overwhelmingly lower than the heat conductivity of the heat radiating portion 23a. As a result of suppressing heat conduction from the heat radiating part 23a to the heat insulating member 4, heat conduction to the resin part 23b is also suppressed.

  The length of the protrusion 26 of the resin portion 23b described above is more preferably long enough that the portion of the resin portion 23b where the protrusion 26 is not formed and the heat insulating member 4 do not contact each other. Thereby, in parts other than the projection part 26, the thermal radiation part 23a and the resin part 23b are provided apart, and the resin part 23b and the heat insulation member 4 are also provided apart. Therefore, heat conduction from the heat radiating part 23a to the resin part 23b and heat conduction from the heat insulating member 4 to the resin part 23b can be minimized.

  Furthermore, when the resin part 23b and the heat insulation member 4 are provided apart from each other, a space S is formed between the heat insulation member 4 and the part of the resin part 23b indicated by a broken line in the drawing. Thereby, when adjusting the length of the wire 3a and shortening, the excess wire 3a is accommodated in this space S. Therefore, the length of the wire 3a can be adjusted by effectively using the space S between the resin portion 23b and the heat insulating member 4.

  The shape of the heat insulating member 4 is not particularly limited, but it is preferable that the heat insulating member 4 be provided apart from the light source installation portion 24. For example, in FIG. 5, the heat insulating member 4 has a recessed portion 4 a that is recessed from the heat radiating portion 23 a side to the resin portion 23 b side. The recess 4 a is preferably provided so that the heat insulating member 4 is separated from the light source installation part 24 and the light source module 21. That is, since the light source module 21 is installed in the light source installation unit 24, the light source installation unit 24 becomes a part that absorbs heat from the light source module 21 and generates heat. The heat insulating member 4 is provided so as to avoid the light source installation part 24 and the light source module 21 which are the heat generating part of the heat radiating part 23a. For this reason, the light source installation part 24 and the light source module 21, and the heat insulation member 4 become non-contact by the recessed part 4a. As a result, heat is not easily transmitted directly from the light source installation part 24 and the light source module 21 to the heat insulating member 4.

  The heat insulating member 4 also functions as a spacer for providing the resin portion 23b and the heat radiating portion 23a (especially the light source installation portion 24 and the light source module 21) apart from each other. For this reason, conduction of heat from the heat radiating portion 23a to the resin portion 23b is suppressed. Therefore, the temperature rise of the resin part 23b can be reliably suppressed. As long as the heat insulating member 4 is separated from at least one of the light source installation part 24 and the light source module 21, the temperature rise of the resin part 23b can be suppressed.

(Relationship between the light source installation part 24 and the incident surface 22a of the light guide plate 22)
FIG. 6 is a cross-sectional view illustrating the relationship between the incident surface 22 a of the light guide plate 22 and the light source installation surface 24 a of the light source installation unit 24 in the illumination device 10.

  In the illuminating device 10, the heat radiating part 23a and the light guide plate 22 are molded products. That is, the light source installation part 24 of the heat radiating part 23a and the incident surface 22a of the light guide plate 22 are formed by molding in order to form with high accuracy. However, when the heat radiating part 23a and the light guide plate 22 are formed by molding, the light source installation part 24 and the incident surface 22a of the light guide plate 22 have a draft angle formed when the mold is removed from the mold. That is, the light source installation surface 24a and the incident surface 22a of the light guide plate 22 are inclined surfaces with respect to the direction in which the mold is pulled out.

  Therefore, in the lighting device 10, as illustrated in FIG. 6, the light source installation surface 24 a formed by molding and the incident surface 22 a of the light guide plate 22 are inclined in the same direction. More specifically, in FIG. 6, the light source installation surface 24a and the incident surface 22a are arranged in parallel to each other. Thereby, compared with the case where the light source installation surface 24a and the incident surface 22a of the light guide plate 22 are inclined to the opposite sides, the light from the light source module 21 is reflected by the incident surface 22a of the light guide plate 22. It is possible to increase the ratio of incident light. Therefore, it is possible to provide the lighting device 10 that can efficiently make the light emitted from the light source module 21 incident on the light guide plate 22.

  In particular, in FIG. 6, the light source installation surface 24 a and the incident surface 22 a of the light guide plate 22 are parallel to each other. Thereby, the incident surface 22a of the light guide plate 22 is arranged perpendicularly to the optical axis A indicated by the alternate long and short dash line in the drawing of the light source module 21 attached to the light source installation surface 24a. Therefore, the incident efficiency (light coupling efficiency) of the light emitted from the light source module 21 to the light guide plate 22 can be maximized.

  In the illumination device 10, both the light source installation surface 24a and the incident surface 22a of the light guide plate 22 are formed by molding. However, when at least one of the light source installation surface 24a and the incident surface 22a of the light guide plate 22 is formed by molding, the light source installation surface 24a or one inclined surface of the incident surface 22a inevitably formed by the draft of the molding. The other surface may be inclined in the same direction according to the inclination direction. The other surface may be formed by molding so as to be an inclined surface in the same direction corresponding to one inclined surface, or may be formed by other methods such as cutting. Thus, in the illuminating device 10, it is preferable that the other surface inclines in the same direction as one inclined surface of the light source installation surface 24a or the incident surface 22a formed by the draft of the molding. Thereby, compared with the case where the light source installation surface 24a and the incident surface 22a of the light guide plate 22 are not inclined in the same direction, the light emitted from the light source module 21 can be efficiently incident on the light guide plate 22. it can.

(Relationship between shape of light guide plate 22 and emitted light)
FIG. 7 is a diagram showing a light path for guiding light guide plates having different shapes in the lighting device according to the embodiment of the present invention, and FIG. 7A is incident on the flat light guide plate 22 ′. FIG. 7B is a cross-sectional view showing the path of light incident on the curved light guide plate 22. FIG. 7B shows an optical path of the light guide plate 22 that is curved as it is away from the light source module 21, and FIG. 7A shows a comparison of the light guide plate 22 ′ of the flat light guide plate 22 ′ as a comparison. The optical path is shown.

  As is clear from a comparison between FIGS. 7A and 7B, the light guide plate 22 ′ has a flat plate shape (FIG. 7A) and the light guide plate 22 has a curved shape (FIG. 7A). The light guides the inside through a different path from that in FIG.

  That is, as shown in FIG. 7A, in the case of a flat light guide plate 22 ′, the light incident from the incident surface of the light guide plate 22 ′ is totally reflected inside the light guide plate 22 ′, and the light guide plate 22 ′. It propagates toward the outer edge 22d '(the surface opposite to the incident surface 22a'). That is, the incident angle (θ1) of the light reaching the upper surface 22c ′ of the light guide plate 22 ′ and the reflection angle (θ2) of the light reflected by the upper surface 22c ′ have a relationship of θ1 = θ2. For this reason, the light incident on the light guide plate 22 ′ is not easily emitted from the upper surface 22 c ′ and the lower surface 22 b ′ which are the emission surfaces in the vicinity of the light source module 21, and is guided to the outer edge portion 22 d ′. Becomes relatively darker than the vicinity of the outer edge portion 22d ′, and the luminance of the light emitting surface on the lower surface 22b ′, which is the exit surface of the light guide plate 22 ′, becomes uneven. Further, in the case of the flat light guide plate 22 ′, the light source module 21 (particularly the LED chip) is easily visible from the outer edge portion 22 d. In the case of the flat light guide plate 22, the ratio of the light emitted from the lower surface 22 b ′ that is the emission surface and the light reflected by the outer edge portion 22 d ′ is approximately 1: 1.

  On the other hand, as shown in FIG. 7B, when the lower surface 22b of the light guide plate 22 is curved toward the irradiation surface side such as a desk top surface or a floor, the reflection angle is reduced while the light guide plate 22 is guided. Change. Specifically, the incident angle (θ1 ′) of the light reaching the upper surface 22c of the light guide plate 22 and the reflection angle (θ2 ′) of the light reflected by the upper surface 22c are θ1 ′ <θ2 ′ (θ1 ′ ≠ θ2 ′). ) And while such a change in angle is repeated, the total reflection condition is broken at either the upper surface 22c or the lower surface 22b. For this reason, compared with the light guide plate 22 ′ shown in FIG. 7A, the light incident on the light guide plate 22 is more easily emitted from the vicinity of the light source module 21 on the lower surface 22 b. Therefore, the light extraction efficiency from the light guide plate 22 can be increased. Thus, it can be said that the curved shape of the light guide plate 22 is a shape that is positively emitted from the upper surface 22c or the lower surface 22b that is the emission surface. For this reason, it can reduce that the outer edge part 22d becomes too bright, reducing that the light source module 21 vicinity becomes dark. Therefore, uniform light can be emitted from the emission surface.

  Further, as shown in FIG. 6, in the curved light guide plate 22, the incident surface 22 a is inclined, and when light from the light source module 21 is incident on the inclined incident surface 22 a substantially perpendicularly, first, the surface of the light guide plate 22. The incident angle θ1 ″ of the light reaching the angle and the reflection angle θ2 ″ of the light reflected on the surface thereof are larger than in the case of FIG. 7B where the incident surface 22a is not inclined. As a result, light can be more actively emitted in the vicinity of the light source module 21. As a result, the light can be emitted from the upper surface 22c or the lower surface 22b, which is the emission surface, with a smaller number of reflections than in the case of FIG. For this reason, it can further reduce that the outer edge part 22d is too bright, further reducing that the light source module 21 vicinity becomes dark. Moreover, in the case of the curved light guide plate 22 as shown in FIG. 6, light can be easily emitted from the upper surface 22 c of the light guide plate 22.

(Shape of light guide plate 22 and irradiation pattern)
FIG. 8 is a diagram illustrating the relationship between the shape of the light guide plate 22 in the illumination device 10 and the irradiation pattern from the lower surface 22b. In FIG. 8, the case where the shape of the light guide plate 22 when viewed from above is a rectangle and the case where it is a trapezoid are compared.

  Specifically, the illuminating device 10 is a pendant light having an irradiation surface such as a desk top or a floor. For example, the illuminating device 10 is assumed to be suspended from the table T as an irradiation surface by about 70 to 80 cm. The light guide plates 22 and 22 ′ are provided so as to protrude from the side surface of the housing 23. A broken line in the drawing indicates a light guide plate 22 ″ having a rectangular shape in plan view. The light guide plate 22 ″ has a uniform cross-sectional area and width in a direction parallel to the incident surface 22a ″ even when the light guide plate 22 ″ is separated from the incident surface 22a ″. In this case, as indicated by the wavy line, the shape of the irradiation pattern P1 is elliptical on the irradiation surface. As a result, since the irradiation amount to the four corners C of the table T is reduced, the four corners C become dark.

  On the other hand, the solid line in the figure shows two light guide plates 22 having a trapezoidal shape in plan view, which are arranged on both sides of the housing 23. The width of the light guide plate 22 in the direction parallel to the longitudinal direction of the incident surface 22a increases as the width of the light guide plate 22 increases from the incident surface 22a in the emission direction of the light source module. That is, as the light guide plate 22 moves away from the incident surface 22a, the cross-sectional area and the width in the direction parallel to the incident surface 22a are increased. In this case, as indicated by the alternate long and short dash line, the shape of the irradiation pattern P2 is rectangular on the irradiation surface. Moreover, the irradiation area of the irradiation pattern P2 is larger in the direction of the corner C of the table T than the irradiation pattern P1. Accordingly, it is possible to provide an illumination device that can uniformly irradiate the irradiation surface of the table T.

  Further, as shown in FIG. 7A described above, in the case of the flat light guide plate 22 ′, the incident light has a high ratio of light guided to the outer edge portion 22 d ′. For this reason, the closer to the outer edge portion 22d 'of the light guide plate 22', the brighter it becomes. Further, when the ratio of the amount of light emitted from the vicinity of the outer edge portion 22d ′ is high, the light is diffused by the light diffusing material dispersed inside the light guide plate 22 ′, leading to an increase in the light irradiated to the outside of the table T. .

  For this reason, as shown in FIG. 7B, the light guide plate 22 is preferably a curved light guide plate 22 that is curved as the distance from the incident surface 22a in the light emitting direction of the light source module 21 increases. As described above, in the case of the curved light guide plate 22 shown in FIG. 7B, the ratio of the light emitted from the vicinity of the light source module 21 on the lower surface 22b and the upper surface 22c, which are the emission surfaces, is as shown in FIG. Since the height is higher than that of the light plate 22 ′, it is possible to reduce the light emitted to the outside of the table T while making the vicinity of the light source module 21 brighter.

  Furthermore, in the case of the curved light guide plate 22 curved so that the outer edge portion 22d of the light guide plate 22 faces downward, the cross section perpendicular to the longitudinal direction of the light source module 21 of the light guide plate 22 extends from the outer edge portion 22d to the incident surface 22a. Curved rather than straight. Therefore, it is possible to reduce the possibility that the light source module 21 (particularly the LED chip that is lit) is easily visually recognized from the outer edge portion 22d side. Note that “the outer edge portion 22d of the light guide plate 22 faces downward” indicates that the lighting device 10 faces in the floor direction when suspended or attached to the ceiling.

  Furthermore, it is preferable that the light diffusing material is scattered inside the light guide plate 22. Thereby, in addition to the light guide plate 22 being curved, the light source module 21 (particularly the LED chip that is lit) can be reduced from being easily recognized by including a light diffusing material.

  Further, as shown in FIGS. 7A and 7B, the outer edge portions 22d and 22d ′ of the light guide plates 22 and 22 ′ are in relation to the upper surfaces 22c and 22c ′ and the lower surfaces 22b and 22b ′, which are emission surfaces. An inclined surface (tapered surface) is preferable. Thereby, the light reflected by the outer edge portions 22d and 22d 'is emitted in the direction of the irradiation surface.

(Holding structure of light guide plate 22)
FIG. 9 is a perspective view showing a method of positioning the light guide plate 22 with respect to the heat radiating portion 23a. FIG. 10 is an enlarged view of a positioning portion indicated by a wavy line in FIG.

  As shown in FIGS. 9 and 10, a positioning pin (positioning protrusion) 27 for positioning the light source module 21 and the incident surface 22a of the light guide plate 22 is formed on the back surface of the heat radiating portion 23a. The positioning pin 27 is set so that the distance between the light source module 21 and the incident surface 22a of the light guide plate 22 becomes a predetermined value. For this reason, the entrance surface 22 a of the light guide plate 22 is accurately positioned with respect to the light source module 21 by engaging the notch 22 e with the positioning pin 27.

  The notch 22e is provided with a slight clearance in the longitudinal direction and the short direction of the light guide plate 22. For this reason, the light guide plate 22 can be absorbed regardless of the direction in which the light guide plate 22 expands or contracts due to environmental changes. Thereby, damage to the light guide plate 22 due to expansion or contraction can be prevented.

  A screw hole 27 a is formed at the center of the positioning pin 27. Screw holes 41 a are also formed in the four corners of the heat insulating member 4. A screw 41 for fixing the heat insulating member 4 to the heat radiating portion 23a (see FIG. 5) is inserted into the screw hole 41a and the screw hole 27a and fastened. Accordingly, the light guide plate 22 can be sandwiched between the heat insulating member 4 and the heat radiating portion 23 a while positioning the incident surface 22 a of the light guide plate 22 with respect to the light source module 21. That is, the light guide plate 22 can be fixed to the heat radiating portion 23a. Thereby, bending and distortion of the light guide plate 22 due to expansion or contraction can be prevented.

(Distance between the light source module 21 and the incident surface 22a: running distance)
A plurality of single-color or multi-color LED chips are mounted on the light source module 21. When LED chips of a plurality of colors are mounted, the LED chips of each color are not lit at the same time. Only the LED chip corresponding to the set color lights up. At this time, if the distance from the light source module 21 to the incident surface 22a of the light guide plate 22 is too short, unevenness is likely to occur in the emitted light.

  Therefore, the distance from the light source module 21 to the incident surface 22a of the light guide plate 22 is preferably set to such an extent that such unevenness does not occur. As a result, the light of the LED chips of the same color can be sufficiently mixed and then incident on the light guide plate 22. The distance from the light source module 21 to the incident surface 22a of the light guide plate 22 is preferably the same as the pitch of the LED chips of the same color, for example. Thereby, a sufficient run distance can be ensured. Accordingly, light that is sufficiently mixed and has no unevenness can be incident on the light guide plate 22.

(Reflection sheet 5)
FIG. 11 is a cross-sectional view showing a configuration in which the reflection sheet 5 is provided between the light source module 21 and the incident surface 22 a of the light guide plate 22.

  As shown in FIG. 11, the reflection sheet 5 is provided in the vicinity of the optical coupling portion between the light source module 21 and the light guide plate 22.

  In the illuminating device 10, the light-guide plate 22 in which the light-diffusion material (light extraction means) was scattered may be applied. In this case, the light diffusing material cannot be eliminated only on the incident surface 22 a of the light guide plate 22, and the light diffusing material is distributed throughout the light guide plate 22. For this reason, a part of the light reaching the incident surface 22a is diffused by the light diffusing material on the incident surface 22a without entering the light guide plate 22 (not optically coupled). Further, of the light emitted from the light source module 21, a part of the light having a large emission angle does not enter the incident surface. For this reason, the incident efficiency to the light-guide plate 22 becomes low.

  Therefore, it is preferable that the reflection sheet 5 is provided as a reflection member in the vicinity of the incident surface 22a of the light source module 21 and the light guide plate 22 (in the vicinity of the optical coupling portion). Two reflection sheets 5 are provided so as to sandwich the incident surface 22 a of the light guide plate 22. As a result, the light diffused on the incident surface 22a and the light emitted from the light source module 21 having a large emission angle (light not incident on the incident surface 22a) are reflected by the reflection sheet 5 and guided again to the incident surface 22a. It is burned. Therefore, the utilization efficiency of light emitted from the light source module 21 (incidence efficiency on the light guide plate 22) can be improved.

[Embodiment 2]
(Different illumination device 10a)
Based on FIG. 12, the illuminating device which concerns on Embodiment 2 is demonstrated. FIG. 12 is a perspective view of an illumination device 10a according to another embodiment of the present invention. In FIG. 12, only the illumination unit 2 a in the illumination device 10 a is illustrated, but the illumination device 10 a also includes the fixing unit 1 (see FIG. 1) as in the illumination device 10.

  The illuminating device 10a of this embodiment differs in the shape of the light-guide plate 22 from the light-guide plate 22 of the illuminating device 10 of Embodiment 1. FIG. That is, the illuminating device 10a includes a disk-shaped light guide plate 22 having an opening O at the center.

  As shown in FIG. 12, the illumination unit 2 a is composed of the same members as the illumination unit 2. That is, the illuminating unit 2a includes a housing 23 composed of a heat radiating part 23a and a resin part 23b, a heat insulating member 4 provided between the heat radiating part 23a and the resin part 23b, two light source modules 21 as light sources, and a light source module. The light guide plate 22 is provided opposite to the light guide plate 21, and the two reflection sheets 5 are provided in the vicinity of the optical coupling portions on both surfaces of the light guide plate 22.

  The illumination part 2a is suspended from the ceiling by three wires 3a connected to the heat dissipation part 23a. FIG. 13 is a perspective view of the heat dissipation part 23a in the illumination part 2a of the illumination device 10a. On the top surface of the heat dissipating part 23a, an adjustment member 31a for adjusting the length of each wire 3a and fixing the wire 3a with the adjusted length and a cable fixing part 31b for fixing the power supply line 3b are provided. Yes. One end of each of the wire 3a and the power supply line 3b is connected to the fixing portion 1 (not shown), and the other end is connected to the top surface (the adjusting member 31a or the cable fixing portion 31b) of the heat radiating portion 23a.

  FIG. 14 is a diagram illustrating the inside of the housing 23 in the illumination unit 2a of the illumination device 10a. The heat dissipating part 23a and the resin part 23b or the heat insulating member 4 are provided apart from each other. For this reason, a space S is formed between the heat dissipating part 23 a indicated by the broken line in the drawing and the resin part 23 b or the heat insulating member 4. Thereby, when adjusting the length of the wire 3a and shortening, the excess wire 3a is accommodated in this space S. Therefore, the length of the wire 3a can be adjusted by effectively using the space S.

  FIG. 15 is a perspective view showing the bottom of the heat dissipating part 23a in the illumination part 2a of the illumination device 10a. FIG. 16 is a cross-sectional view illustrating a configuration in which the reflection sheet 5 is provided between the light source module 21 and the incident surface 22a of the light guide plate 22 in the lighting device 10a.

  As shown in FIG. 15, a plurality of light source modules 21 are arranged in a ring shape (strictly in a polygonal shape) at the bottom of the heat radiating portion 23a. As shown in FIG. 16, the incident surface 22 a of the light guide plate 22 is disposed so as to face each light source module 21. Further, a reflection sheet 5 is provided as a reflection member in the vicinity of the incident surface 22a of the light source module 21 and the light guide plate 22 (in the vicinity of the optical coupling portion). Inside the housing 23, the vicinity of the incident surface 22 a of the light guide plate 22 is sandwiched between the two reflection sheets 5. As a result, the light diffused on the incident surface 22a and the light emitted from the light source module 21 having a large emission angle (light not incident on the incident surface 22a) are reflected by the reflection sheet 5 and guided again to the incident surface 22a. It is burned. Therefore, the utilization efficiency of light emitted from the light source module 21 (incidence efficiency on the light guide plate 22) can be improved.

  FIG. 17 is a perspective view illustrating a method of positioning the light guide plate 22 with respect to the heat radiating portion 23a in the lighting device 10a. Positioning pins (positioning protrusions) 27 for positioning the light source module 21 and the incident surface 22a of the light guide plate 22 are formed in the vicinity of the joints of the light source modules 21 in the heat radiating portion 23a. On the other hand, the light guide plate 22 has a notch 22e corresponding to the positioning pin 27. For this reason, the entrance surface 22 a of the light guide plate 22 is accurately positioned with respect to the light source module 21 by engaging the notch 22 e with the positioning pin 27.

  The notch 22e is provided with a slight clearance in the longitudinal direction and the short direction of the light guide plate 22. For this reason, the light guide plate 22 can be absorbed regardless of the direction in which the light guide plate 22 expands or contracts due to environmental changes. Thereby, damage to the light guide plate 22 due to expansion or contraction can be prevented.

  A screw hole 27 a is formed at the center of the positioning pin 27. Screw holes 41 a are also formed in the four corners of the heat insulating member 4. A screw 41 for fixing the heat insulating member 4 to the heat radiating portion 23a (see FIG. 5) is inserted into the screw hole 41a and the screw hole 27a and fastened. Accordingly, the light guide plate 22 can be sandwiched between the heat insulating member 4 and the heat radiating portion 23 a while positioning the incident surface 22 a of the light guide plate 22 with respect to the light source module 21. That is, the light guide plate 22 can be fixed to the heat radiating portion 23a. Thereby, bending and distortion of the light guide plate 22 due to expansion or contraction can be prevented.

  FIG. 18 is a diagram illustrating a path of light that guides the inside of the light guide plate 22 in the lighting device 10a. Even in the illumination device 10a, the outer edge portion 22d of the light guide plate 22 has an inclined surface (tapered surface). The outer edge portion 22d is coated with a reflective film that reflects light. Thereby, the light reflected by the outer edge portion 22d is emitted in the direction of the irradiation surface. Therefore, it is possible to improve the illuminance of the irradiated surface by suppressing light that escapes from the outer edge portion 22d in a direction substantially parallel to the irradiated surface such as the floor surface or the desk surface. Thus, the outer edge portion 22d can be said to be a reflection surface that reflects the light guided inside the light guide plate 22 and emits the light from the lower surface 22b that is the emission surface.

  The outer edge portion 22d (inclined surface) may not be coated with a reflective film that reflects light. In this case, since the outer edge 22d is inclined with respect to the lower surface 22b, a part of the light incident on the outer edge can be totally reflected in the direction of the lower surface 22b and emitted from the lower surface 22b. However, since the light reflection efficiency is improved by applying the reflective film to the outer edge portion 22d, it is advantageous in that the illuminance on the irradiated surface can be improved. In addition, the inclined surface (outer edge portion 22d) can be configured by a plane, a curved surface, or a surface obtained by combining a plane and a curved surface. By making the inclined surface flat, the processing of the light guide plate 22 becomes easy, and the lighting device 10 can be provided with high mass productivity and low cost. Moreover, the light extraction efficiency and the illumination intensity of the irradiated surface can be improved by making the inclined surface a curved surface.

  In each embodiment, an illumination device (illumination module) including the LED 12 as a light source has been described. However, the light source is not limited to the LED, and may be various light emitting elements such as an organic EL, for example.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

3a Wire (hanging member)
4 Heat insulation member 10 Illuminating device 10a Illuminating device 21 Light source module (light source)
22 Light guide plate (light guide member)
22a Incident surface 22d Outer edge (inclined surface)
23 Housing 23a Heat radiation part (first housing part)
23a 'upper surface (first surface)
23b Resin part (second housing part)
23b 'lower surface (second surface)
23d Side surface (first side surface)
23d 'side surface (second side surface)
24 Light source installation part 24a Light source installation surface

Claims (6)

An illumination device comprising a light source and a housing in which the light source is installed, wherein light from the light source is emitted from a first side surface of the housing,
The above housing is
A first housing part on which the light source is arranged and forms a first surface adjacent to the first side part;
An illuminating device comprising: a second casing portion that is made of a material having a lower thermal conductivity than the first casing portion and forms a second surface facing the first surface.   The lighting device according to claim 1, wherein the housing includes a heat insulating member between the first housing portion and the second housing portion. The first housing part includes a light source installation part in which the light source is installed,
The lighting device according to claim 2, wherein the heat insulating member is provided apart from at least one of the light source installation part and the light source.   The illumination according to any one of claims 1 to 3, further comprising a light guide member that receives light emitted from a side surface portion of the housing, guides the incident light to the inside, and emits the light. apparatus.   5. The lighting device according to claim 1, wherein the second casing portion forms a second side surface portion adjacent to the first side surface portion from which light from the light source is emitted. A suspension member for suspending the housing;
The lighting device according to any one of claims 1 to 5, wherein the second surface is a lower surface of the casing suspended by the suspension member.