JP6662508B2 - Lighting module - Google Patents

Description

  The present invention relates to a lighting module.

  2. Description of the Related Art A lighting module, which is a surface emitting device using an LED (Light Emitting Diode) light source, employs a structure for equalizing the brightness of a light emitting surface of the lighting module. Patent Document 1 discloses an illumination module in which an LED light source is arranged along an end surface of a light guide plate, light emitted from the light guide plate is incident on the light diffusion plate, and light is emitted from the light emission surface of the light diffusion plate. ing. In this lighting module, a convex portion facing the light emitting surface of the light guide plate is provided at a peripheral portion of the light diffusing plate, and by controlling light incident on the convex portion, the luminance at the peripheral portion of the lighting module is controlled. The decline is suppressed.

JP 2014-150049 A

  However, in the field of lighting, there is a need to further suppress a decrease in luminance at the peripheral portion of the lighting module in order to increase the commercial value of the lighting module. In addition, even when a large-sized lighting device is configured by arranging a plurality of lighting modules side by side, it is necessary to make the boundaries between the lighting modules inconspicuous, and therefore, it is desired to further suppress a decrease in luminance at the peripheral portion of the lighting modules. There is a need.

  Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lighting module capable of suppressing a decrease in luminance at a peripheral portion of the lighting module as compared with the related art.

[1] A lighting module according to the present invention includes a light guide plate having an end face and a first light exit surface, a light source arranged along the end face and receiving light from the end face, and the first light of the light guide plate. A light diffuser disposed on the side of the light exit surface and having a first light incident surface on which light emitted from the first light exit surface enters, and a second light exit surface on which light incident from the first light incident surface exits A light diffusion plate protruding toward the light guide plate, and opposing the peripheral edge of the light guide plate on the end face side where at least the light source is arranged. And a convex portion having a second light incident surface on which light emitted from the peripheral portion is incident, and the light diffusion plate is provided at the peripheral portion of the second light exit surface. Having an inclined surface connecting the light exit surface and the outer peripheral end surface of the light diffusing plate. And butterflies.

  According to the illumination module of the present invention, since the light diffusion plate has the inclined surface at the peripheral edge of the second light exit surface, the rising angle of the light beam emitted from the peripheral edge (inclined surface) of the second light exit surface can be reduced. (See FIG. 11 described later). Thereby, when the second light emission surface is viewed from the emission side, it is possible to suppress a decrease in luminance at the peripheral portion of the illumination module as compared with the related art.

  Further, according to the lighting module of the present invention, as described above, when a plurality of lighting modules are juxtaposed, it is possible to configure a large-sized lighting device in which a drop in luminance between adjacent lighting modules is small. Further, according to the lighting module of the present invention, since the light diffusion plate has the inclined surface at the peripheral portion of the second light emitting surface, even when the lighting module is not lit, the boundary between the adjacent lighting modules is inconspicuous. The device can be configured.

[2] In the lighting module of the present invention, the inclined surface is preferably a convex surface.

  According to the illumination module of the present invention, since the inclined surface is a convex surface, the rising angle of the light beam emitted from the peripheral portion (inclined surface) of the second light emission surface can be increased toward the outer peripheral side of the inclined surface. (See FIG. 11 described later.) Thereby, when the second light emission surface is viewed from the emission side, it is possible to further suppress a decrease in luminance at the peripheral portion of the illumination module.

[3] In the lighting module of the present invention, it is preferable that the inclined surface is a curved surface whose center of curvature O1 is located closer to the first light incident surface than the outer peripheral end surface of the light diffusion plate.

  According to the illumination module of the present invention, since the inclined surface is the curved surface as described above, the outer peripheral side of the inclined surface has a larger rising angle of the light beam emitted from the peripheral portion (inclined surface) of the second light emitting surface. (See FIG. 11 described later). Thereby, when the second light emission surface is viewed from the emission side, it is possible to further suppress a decrease in luminance at the peripheral portion of the illumination module.

  According to the lighting module of the present invention, since the inclined surface is the curved surface as described above, the rising angle of the light beam emitted from the peripheral portion (inclined surface) of the second light emitting surface is continuously changed. Therefore, the change in luminance becomes smooth, and it is possible to make it difficult for a viewer to feel uneven luminance.

[4] In the lighting module according to the aspect of the invention, a ratio of a radius of curvature of the curved surface to a distance between the second light incident surface and the second emission surface of the ridge is in a range of 5% to 75%. Is preferred.

  When the ratio is less than 5%, the amount of light incident on the curved surface is small (that is, the amount of light incident on the flat surface on the center side of the second light emitting surface is larger than the curved surface) (see FIG. 14 described later). (C). However, the effect of improving the luminance at the periphery of the lighting module is not high enough to be visually recognized by a viewer (see FIG. 14 (b) described later). On the other hand, when the above ratio is 5% or more, the amount of light incident on the curved surface becomes large (see FIG. 15C described later). High enough to be visible.

  On the other hand, if the above ratio exceeds 75%, the ratio of the width of the light ray H to the length of the curved surface becomes small, and the optical path length in the convex portion becomes short (see FIG. 23 (c) described later). ), The luminance on the curved surface increases, and the luminance unevenness increases, which is not preferable (see FIG. 23 (b) described later). On the other hand, when the above ratio is 75% or less, the ratio of the width of the light ray H to the length of the curved surface becomes larger than that when the above ratio exceeds 75%, and the optical path length in the convex portion is reduced. Since the ratio becomes longer than the case where the ratio exceeds 75% (see FIG. 22C described later), the luminance on the curved surface decreases, and the luminance unevenness becomes less noticeable than when the ratio exceeds 75% (described later). (See FIG. 22B). Here, the light ray H refers to a light ray that enters from the second light incident surface and travels in a state where it is not scattered in the ridge portion 26 of the light totally reflected on the inner side surface.

  In FIG. 15B described later, the luminance at the peripheral portion of the illumination module does not seem to be much improved as compared with the case of FIG. 14B, but the peripheral portion is actually viewed from the emission side. In the sensory evaluation of the case where the above ratio is in the range of 5% to 75%, improvement and uniformity of the luminance at the peripheral portion are observed, and the luminance distribution of the entire surface of the second light emission surface includes the luminance including the peripheral portion. It has been confirmed that it is possible to achieve uniformity.

[5] In the lighting module according to the aspect of the invention, a ratio of a radius of curvature of the curved surface to a distance between the second light incident surface and the second emission surface of the ridge is in a range of 10% to 70%. Is preferred.

  When the above ratio is 10% or more, the amount of light incident on the curved surface is further increased (see FIG. 15 (c) described later), so that the effect of improving the brightness at the peripheral edge is further enhanced (see the diagram described later). 15 (b).). On the other hand, when the above ratio is 70% or less, the ratio of the width of the light beam H to the length of the curved surface is further increased, and the optical path length in the convex portion is further increased (see FIG. 21 described later). (See FIG. 21C.) In addition, the luminance on the curved surface is reduced, and the luminance unevenness becomes even less noticeable (see FIG. 21B described later).

[6] In the lighting module according to the aspect of the invention, a ratio of a radius of curvature of the curved surface to a distance between the second light incident surface and the second emission surface of the ridge is in a range of 20% to 60%. Is preferred.

  When the above ratio is 20% or more, the amount of light incident on the curved surface is further increased (see FIG. 16 (c) described later), so that the effect of improving the luminance at the peripheral edge is further enhanced (see the diagram described later). 16 (b).). On the other hand, when the above ratio is 60% or less, the ratio of the width of the light ray H to the length of the curved surface is further increased, and the optical path length in the convex portion is further increased (see FIG. 20 described later). (See FIG. 20C.), The luminance on the curved surface is reduced, and the luminance unevenness becomes even less noticeable (see FIG. 20B described later).

[7] In the lighting module according to the aspect of the invention, between the peripheral portion of the first light exit surface and the second light incident surface, the second light exits from the peripheral portion of the first light exit surface. It is preferable to further include a light shielding unit for shielding a part of the light incident on the incident surface.

  According to the illumination module of the present invention, since the peripheral portion of the light diffusing plate (second light exit surface) is close to the light source, the luminance is likely to be higher than the inside. Therefore, by providing the light shielding portion at the above-mentioned portion, it is possible to shield a part of the light incident on the ridge portion and reduce the uneven brightness at the peripheral portion.

[8] In the lighting module according to the aspect of the invention, the light shielding portion may include a position P1 at which a virtual line L1 passing through a center O of the curved surface in a circumferential direction and a center of curvature O1 of the curved surface intersects with the second light incident surface. More preferably, it does not protrude toward the first incident surface.

  With such a configuration, it is possible to secure a certain amount of light incident from the second light incident surface of the light diffusion plate 2, so that the second light exit surface is viewed from the exit side. It is possible to suppress a decrease in luminance at the peripheral portion.

[9] In the lighting module according to the aspect of the invention, the light shielding unit may be configured such that an imaginary line L3 orthogonal to the second light incident surface and passing through a center O2 of the curved surface in a circumferential direction is the second light incident surface. It is preferable to protrude from the position P2 that intersects with the first incident surface side.

  With such a configuration, light rays that directly travel from the light source to the peripheral portion can be blocked, so that the luminance unevenness at the peripheral portion can be further reduced.

[10] In the lighting module of the present invention, the lighting module further includes a holding case that houses the light guide plate and the light source, and an outer peripheral end surface of the light diffusing plate is in the same plane as an outer peripheral side surface of the holding case. Or it is preferably arranged outside the outer peripheral side surface of the holding case.

  As described above, the outer peripheral end surface of the light diffusion plate is disposed in the same plane as the outer peripheral side surface of the holding case, or is disposed outside the outer peripheral side surface of the holding case, so that the illumination module can be placed on the emission surface side. When viewed from above, the outer peripheral side surface of the holding case becomes difficult to see. Further, when a plurality of lighting modules are juxtaposed, the outer peripheral end surfaces of the adjacent light diffusing plates can be in close contact with each other, and it is possible to prevent a dark portion from being generated around each light diffusing plate. It is preferable that the outer peripheral end surface of the light diffusion plate protrudes from the outer peripheral side surface of the holding case by a negative tolerance.

[11] In the lighting module of the present invention, it is preferable that a thickness of an outer peripheral side surface of the holding case is smaller than a thickness of an outer peripheral end surface of the light diffusion plate.

  As described above, since the thickness of the holding case is smaller than the thickness of the light diffusion plate, it is possible to make the holding case hard to see when the illumination module is viewed obliquely in the emission direction.

[12] A large-sized lighting device according to the present invention includes a plurality of lighting modules according to the present invention, and the plurality of lighting modules are arranged so that outer peripheral end surfaces of the light diffusing plate are in contact with each other.

  ADVANTAGE OF THE INVENTION According to the large illuminating device of this invention, the boundary between adjacent lighting modules can be made less noticeable.

It is an outline view showing lighting 1 module concerning an embodiment. FIG. 2 is a plan view of the lighting module 1 shown in FIG. 1 as viewed from the front side, and is an explanatory diagram schematically showing an arrangement of each light source unit. FIG. 2 is a perspective view of the lighting module 1 shown in FIG. 1 as viewed from a back side. FIG. 4 is a cross-sectional view illustrating a cut surface cut along a cutting line AA in FIG. 3. It is explanatory drawing which shows the path | route of the light until the light radiate | emitted from LED light source radiates | emits from the 2nd light emission surface of a light-diffusion plate. FIG. 4 is a cross-sectional view showing a cut surface cut along a cutting line BB in FIG. 3. FIG. 4 is a cross-sectional view showing a cut surface cut along a cutting line CC of FIG. 3. FIG. 4 is a cross-sectional view illustrating a cut surface cut along a cutting line DD in FIG. 3, illustrating a fixing structure at a position where a circuit connecting portion of an LED board is interposed between a holding case and a frame. FIG. 9 is a cross-sectional view showing a fixing structure at a position where no LED board is interposed between the holding case and the frame with respect to FIG. 8. It is a figure which shows a part of connection structure of an LED board and a connection board. It is a figure shown in order to explain the effect of the lighting module concerning an embodiment. FIG. 9 is a diagram shown for explaining a protruding amount of a light shielding unit 46. It is a figure showing a simulation method in a test example. FIG. 9 is a diagram illustrating a simulation result in Design Example 1. FIG. 9 is a diagram illustrating a simulation result in Design Example 2. FIG. 14 is a diagram illustrating a simulation result in Design Example 3. FIG. 14 is a diagram illustrating a simulation result in Design Example 4. FIG. 14 is a diagram illustrating a simulation result in Design Example 5. FIG. 14 is a diagram illustrating a simulation result in Design Example 6. FIG. 14 is a diagram illustrating a simulation result in Design Example 7. FIG. 14 is a diagram illustrating a simulation result in Design Example 8. FIG. 14 is a diagram illustrating a simulation result in Design Example 9; FIG. 14 is a diagram showing a simulation result in Design Example 10. It is a figure shown in order to explain the modification of inclined surface 14.

  Hereinafter, a lighting module according to an embodiment of the present invention will be described with reference to the drawings.

1. Configuration of Lighting Module FIG. 1 is an external view showing a lighting module 1 according to an embodiment, wherein (A) in the upper part is a perspective view and (B) in the lower part is a side view. In the following description, the direction of arrow X1 is on the right (right side), the direction of arrow X2 is on the left (left side), the direction of arrow Y1 is forward (front side), and the direction of arrow Y2 is rear (rear side). Side), the arrow Z1 direction is defined as an upper direction (upper surface side), and the arrow Z2 direction is defined as a lower direction (lower surface side). In addition, the arrow Z1 direction may be described as a front side, and the arrow Z2 direction may be described as a rear side. Note that the arrow Z1 direction, which is the upward direction (upper surface side), is the illumination direction of the illumination module 1, that is, the illumination light emission side.

  As shown in FIGS. 1A and 1B, the illumination module 1 has a light diffusion plate 2 disposed on the front side and a holding case 3 as a case member disposed on the rear side. The holding case 3 is formed of a metal plate having a high thermal conductivity, but is preferably made of aluminum from the viewpoint of weight reduction. The light diffusion plate 2 and the holding case 3 are integrated by a plurality of fixing members. The upper surface of the light diffusion plate 2 is a second light emission surface 4 for emitting light to the outside. The fixing structure by the fixing member will be described later with reference to FIGS. The outer peripheral side surface 5 of the holding case 3 is arranged in the same plane as the outer peripheral side surface 6 of the light diffusing plate 2 or is arranged inside the outer peripheral side surface 6 of the light diffusing plate 2. In a space sandwiched between the light diffusion plate 2 and the holding case 3, a light guide plate 7, an LED light source 8, which is a light source, a frame 9, and a light shielding frame 10, which will be described later, are housed (see FIGS. 2 and 4). ). The thickness of the four peripheral edges 11 of the holding case 3 in the vertical direction is smaller than the thickness of the inner part 12 of the peripheral edge 11. That is, the inner portion 12 is convex downward with respect to the peripheral portion 11. The inner portion 12 is formed so as to protrude downward from a groove 24 slightly recessed upward from the peripheral edge 11 (see FIG. 3). The lighting module 1 described below is a rectangle having a length of 600 mm in the left-right direction, a length (width) in the front-rear direction of 300 mm, a thickness of the peripheral portion 11 of about 10 mm, and a thickness of an inner portion of about 12 mm. It illustrates a flat case.

  FIG. 2 is a plan view of the illumination module 1 as viewed from the front side, and is an explanatory diagram showing a schematic arrangement of each light source unit. As shown in FIG. 2, the lighting module 1 includes a first light source unit 15 on the left side, a second light source unit 16 on the right side, a third light source unit 17 on the front side, and a third light source unit 17 on the rear side. 4 light source units 18. The first light source unit 15 and the second light source unit 16 are arranged to face each other. Further, the third light source unit 17 and the fourth light source unit 18 are also arranged to face each other. In each of the four light source units from the first light source unit 15 to the fourth light source unit 18, a plurality of LED light sources 8 are arranged along an end face 19 provided on each side of the light guide plate 7. Further, a light shielding frame 10 is arranged so as to cover the LED light source 8 and the end face 19. Although the number and pitch of the LED light sources 8 arranged in each of the four light source units from the first light source unit 15 to the fourth light source unit are simplified in FIG. It can be appropriately selected according to the brightness to be obtained and the width of the second light emitting surface 4. As shown in FIG. 2, in the light shielding frame 10, the left side and the right side are the same and oppose each other, the front side and the rear side are the same and oppose each other, Since the former and the latter differ only in the length, in the following description, the left side will be described as an example.

  As shown in FIG. 2, the light guide plate 7 is provided with protrusions 20 protruding in a direction toward the LED light source 8 from the end surfaces 19 of the four sides at intervals, and an LED is provided between the adjacent protrusions 20. A light source 8 is provided (see also FIGS. 4 and 6). The positions of the protrusions 20 shown in FIG. 2 and the numbers and positions of the LED light sources 8 arranged between the adjacent protrusions 20 are simplified for easy understanding, but can be set arbitrarily. .

  FIG. 3 is a perspective view of the lighting module 1 as viewed from the back side. The holding case 3 includes a peripheral portion 11 continuous with four sides, an inner portion 12 that is more convex than the peripheral portion 11 inside the peripheral portion 11, and an inner portion 12 between the peripheral portion 11 and the inner portion 12. A surrounding groove 24 is provided. A screw 21 serving as a first screw and a screw 22 serving as a second screw are arranged on the peripheral edge 11 as fixing members. In the groove 24, a screw 23 as a third screw is disposed as a fixing member. The fixing structure using the screw 21 will be described later with reference to FIG. 6, the fixing structure using the screw 22 will be described with reference to FIG. 7, and the fixing structure using the screw 23 will be described later with reference to FIG. 8 and FIG. The screws on the left side and the right side facing each other are arranged so as to form a pair, and the screws on the front side and the rear side are also arranged so as to form a pair. The number and arrangement distance (pitch) of each of the screws 21, 22 and 23 are appropriately set according to the plane size of the lighting module 1.

  FIG. 4 is a cross-sectional view showing a cut surface taken along a cutting line AA in FIG. As described above, the illumination module 1 includes the first light source unit 15 on the left side, the second light source unit 16 on the right side, the third light source unit 17 on the front side, and the fourth light source unit 17 on the rear side. And the light source unit 18 of the first embodiment. Although each of the light source units of the first light source unit 15 to the fourth light source unit 18 differs in the number and size of the components, each of the components can be similarly described. The first light source unit 15 on the side will be described as a representative example.

  As shown in FIG. 4, the lighting module 1 includes a light guide plate 7, a plurality of LED light sources 8 arranged along an end face 19 on the left side of the light guide plate 7, and light emitted by the LED light source 8 being directly diffused. A light shielding frame 10 having a U-shaped cross section (a groove having a recess on the side of the light guide plate 7) for shielding the light guide plate 7 from being incident on the plate 2 and preventing leakage to the outside; And a light diffusing plate 2 and the like arranged along the same. In addition, the first light source unit 15 includes an end surface 19, a plurality of LED light sources 8, a light shielding frame 10, and a ridge 26 formed on the left side of the light diffusion plate 2 on the left side of the lighting module 1. And the peripheral portion 27 of the light guide plate 7 which is the portion facing the ridge portion 26. In addition, the end surface 19 is a side surface (corresponding to a bottom surface with respect to the convex portion 20) of the light guide plate 7 formed between the adjacent convex portions 20, as shown in FIG.

  Although FIG. 4 illustrates an example in which the LED light source 8 is used as a light source, the light source may be a CCFL (Cold Cathode Fluorescent Lamp), a light bulb (for example, an incandescent light bulb), a fluorescent lamp, or the like. It can be used, and the type of light source is not limited. However, LED light sources are superior to other light sources in that they consume less power, generate less heat, are easier to miniaturize, and are more cost effective. Therefore, in the following description of each drawing, the case where the LED light source 8 is used as the light source will be described.

  On the back surface 28 side of the light guide plate 7 (the surface opposite to the light diffusion plate 2), a reflection plate 29 is arranged. The reflection plate 29 may be a thin reflection sheet or may be attached to the back surface 28 of the light guide plate 7. In addition, a reflection coat may be provided on the back surface 28 of the light guide plate 7 instead of the reflection plate, or it may be omitted. The planar shape of the reflecting plate 29 is substantially the same as the planar outer shape of the light guide plate 7, but is arranged so as to cover at least a part below the LED light source 8. The reflection plate 29 is in close contact with the back surface 28 of the light guide plate 7 and has a function of reflecting light traveling inside the light guide plate 7 in the direction of the light diffusion plate 2. The frame 9 is provided below the reflection plate 29.

  The frame 9 is formed of a metal plate having a high thermal conductivity, but is preferably made of aluminum from the viewpoint of weight reduction. As shown in FIGS. 2 and 3, the frame 9 has a rectangular frame shape in plan view, and an inner portion of the outer peripheral frame portion 30 is an opening portion 31 penetrating the front and back. The four sides of the outer peripheral frame 30 have substantially the same width. Therefore, the planar shape of the opening 31 is rectangular. The frame 9 has a function of integrating an LED board 35 and the light shielding frame 10 described later (see FIG. 6). Although not shown, the frame 9 may be reinforced by forming a beam connecting the diagonals of the opening 31.

  The light guide plate 7 is formed of an acrylic resin having a high light transmittance, and has an end surface 19 on which light emitted from the LED light source 8 is incident, a first light emission surface 32 facing the light diffusion plate 2, and a first light. A back surface 28 which is a surface opposite to the emission surface 32 is provided. The end surface 19 is an incident surface of light emitted from the LED light source 8, and the first light emission surface 32 is a light emission surface for emitting light from the light guide plate 7 to the light diffusion plate 2. Note that, similarly to the end face 19, the side surface of the convex portion 20 facing the LED light source 8 can also be said to be a light incident surface on which light emitted from the LED light source 8 is incident. The back surface 28 is in close contact with the reflection plate 29 and functions as a reflection surface for light traveling inside the light guide plate 7. The LED light source 8 is mounted on an LED board 35 serving as a light source board, and is arranged along the end face 19. Although the LED light source 8 is arranged in the thickness range of the light guide plate 7, it is more preferable that the LED light source 8 be arranged substantially at the center in the thickness direction of the light guide plate 7. By arranging at the center, the amount of light emitted from the first light emission surface 32 is increased as compared with the case where the light is not arranged at the center.

  Note that the intensity of light incident on the end face 19 of the light guide plate 7 from the LED light source 8 depends on the distance between the LED light source 8 and the end face 19. That is, the intensity of the incident light increases as the LED light source 8 approaches the end face 19, and decreases as the LED light source 8 moves away from the end face 19. As shown in FIG. 2, the light guide plate 7 is provided with a protrusion 20 from the end face 19 of each of the four sides in the direction of the LED light source 8 (toward the LED board 35). The LED light source 8 is disposed in the first position. As shown in FIG. 4, the tip end surface of the projection 20 is in contact with the board side 36 of the LED board 35. That is, the distance between the LED light source 8 and the end face 19 is regulated by the distance from the end face 19 of the tip end face of the projection 20. On the other hand, the board side 36 of the LED board 35 on which the LED light source 8 is mounted is restricted from moving leftward by the side 45 of the light shielding frame 10. In this manner, the distance between the LED light source 8 and the end face 19 is maintained substantially constant, so that the intensity of light incident on the end face 19 can be managed so as to be substantially constant.

  The LED board 35 is a flexible board, and is bent so as to be orthogonal to the board side 36 below the board side 36, as shown in FIG. And a circuit connecting portion 37 extending therefrom. The circuit connecting portion 37 extends toward the right side and is connected to the circuit portion 39 via the connection board 38 (see FIG. 10). The circuit section 39 has a circuit element such as an IC chip and a resistance element for controlling lighting of the LED light source 8. The LED board 35 disposes the circuit connecting portion 37 between the holding case 3 and the lower plate portion 41 of the light shielding frame 10 by inserting the circuit connecting portion 37 into the hole 40 provided in the light shielding frame 10. I can do it.

  Each of the LED elements constituting the LED light source 8 is a white LED element, and controls the light emission from each LED element according to an input signal from the circuit section 39. Note that, as the LED element, an LED lamp in which a red LED element, a green LED element, and a blue LED element are packaged together can be used. In addition, light emission of a designated color can be performed by mixing colors. The LED light source 8 is mounted on the LED board 35 and is fixed to the outer peripheral frame 30 of the frame 9 with the screw 21. This fixing structure will be described later with reference to FIG. 6, and the connection structure between the LED board 35 and the circuit section 39 will be described later with reference to FIG.

  The light shielding frame 10 is formed by bending and bending an aluminum plate. The light-shielding frame 10 extends along the end surface 19 and is orthogonal to the side portion 45 disposed on the back side of the substrate side portion 36 of the LED substrate 35 and from the end of the side portion 45 on the light diffusion plate 2 side. It has an upper plate portion 46 extending to the right side, and a lower plate portion 41 orthogonal to the side portion 45 from the end of the holding case 3 and extending to the right side. The upper plate portion 46 extends to the first light emitting surface 32 side. The upper plate part 46 is a light shielding part, and is described as a light shielding part 46 in the following description. The light shielding frame 10 has a hole 40 penetrating from the front to the back at a connection portion between the side portion 45 and the lower plate portion 41. The circuit connecting portion 37 of the LED board 35 is inserted into the hole 40. In the light shielding frame 10, the light guide plate 7, the reflection plate 29, and the frame 9 are disposed between the light shielding portion 46 and the lower plate portion 41, and integrated with the screw 21 to form the light source unit 50 (see FIG. 6). ). The light shielding unit 46 is provided so that the light emitted from the LED light source 8 does not enter the light diffusion plate 2 as it is, that is, the light from the LED light source 8 2 has a light shielding function that does not allow the light to enter directly.

  The light diffusion plate 2 is formed of an acrylic resin containing light scattering particles, is rectangular in plan view as shown in FIG. 2, and defines the plane shape and the plane size of the lighting module 1. . That is, when the lighting module 1 is viewed from directly above, the holding case 3 below the light diffusion plate 2 is not visible. The light diffusion plate 2 is formed with a ridge 26 projecting toward the first light emission surface 32 of the light guide plate 7. The ridge portion 26 is formed so as to be continuous with the first light source portion 15 on the left side, the second light source portion 16 on the right side, the third light source portion 17 on the front side, and the fourth light source portion 18 on the rear side. Have been. The protruding ridge portion 26 is disposed at a position facing the peripheral edge portion 27 of the light guide plate 7. The plane of the tip of the protruding ridge 26 facing the light guide plate 7 is a second light incident surface 51 on which light emitted from the first light emission surface 32 of the light guide plate 7 is incident. In other words, the peripheral portion 27 of the light guide plate 7 refers to a portion of the ridge 26 facing the second light incident surface 51.

  In the light diffusion plate 2, a concave space 52 surrounded by the ridge 26 is formed in a cross-sectional shape in a plane orthogonal to the arrangement direction of the LED light sources 8. A first light incident surface 53 which is a bottom surface of the concave space 52 (a surface facing the first light exit surface 32) is a light incident surface on which light emitted from the first light exit surface 32 is incident. The outer peripheral side surface 6 of the light diffusion plate 2 is a surface that comes into contact with air, and the inner side surface 54 of the ridge 26 faces the concave space 52 and is a surface that comes into contact with air. Therefore, light that enters the outer peripheral side surface 6 from the inside of the ridge 26 beyond the critical angle is totally reflected by the outer peripheral side surface 6. Light that enters the inner side surface 54 from the inside of the ridge 26 beyond the critical angle is totally reflected by the inner side surface 54. The outer peripheral side surface 6 and the inner side surface 54 are surfaces parallel to each other, and the second light incident surface 51 is a surface orthogonal to the outer peripheral side surface 6 and the inner side surface 54.

  The second light incident surface 51 of the ridge 26 has a shielding region B, which is a region where light emitted from the LED light source 8 or the first light emitting surface 32 (particularly, the peripheral portion 27) is shielded by the light shielding portion 46, And an incident area C where light is incident without being shielded by the light shielding section 46. That is, by arranging the light shielding portion 46 between the second light incident surface 51 of the ridge 26 and the peripheral portion 27 of the light guide plate 7, the light emitted from the peripheral portion 26 becomes the second light incident surface 51. Can be limited. The shielding area B has at least a width (width dimension in the left-right direction) in which light emitted from the LED light source 8 does not directly enter the light diffusion plate 2 without passing through the light guide plate 7. Further, the width of the shielding region B (width in the left-right direction) and the width of the incident region C (width in the left-right direction) are determined by the light incident on the second light incident surface 51 from the first light exit surface 32. When the light is emitted from the second light emission surface 4, the brightness of the entire second light emission surface 4 is set to be uniform. Light that has entered the second light incidence surface 51 from the first light emission surface 32 mainly exits from the peripheral portion of the second light emission surface 4. The width of the shielding region B and the width of the incident region C are set such that the brightness of the peripheral portion of the second light emitting surface 4 approaches the brightness inside the peripheral portion. Assuming that the area of the shielding area B is X and the area of the incident area C is Y, X: Y is preferably 1: 0.5 to 1: 5, and X: Y is more preferably 1: 1 to 1: 3. . The light diffusion plate 2 is in close contact with the light shielding portion 46 of the light shielding frame 10 at the second light incident surface 51 of the ridge 26. The light shielding frame 10 on the right side, the light shielding frame 10 on the front side, and the light shielding frame 10 on the rear side are set under the same conditions as the light shielding frame 10 on the left side.

  As shown in FIG. 5, the light diffusing plate 2 has an inclined surface 14 connecting the second light emitting surface 4 and the outer peripheral end surface 6 of the light diffusing plate 2 at a peripheral portion 13 of the second light emitting surface 4. . In the embodiment, it is a convex surface, more specifically, a curved surface whose center of curvature O1 (see FIG. 12) is located closer to the first light incident surface 53 than the outer peripheral end surface 6 of the light diffusion plate 2.

  The ratio of the radius of curvature of the curved surface to the distance between the second light incident surface 51 and the second emission surface 4 of the ridge 26 is in the range of 5% to 75%. The ratio is preferably in the range of 10% to 70%, and more preferably in the range of 20% to 60%.

  The light shielding portion 46 does not protrude toward the first incident surface 53 from a position P1 at which the virtual line L1 passing through the center O2 in the circumferential direction of the curved surface and the center of curvature O1 of the curved surface intersects the second light incident surface 51. In addition, the light shielding portion 46 is positioned such that the virtual line L3 orthogonal to the second light incident surface 51 and passing through the center O2 in the circumferential direction of the curved surface is more than the first incident light at a position P2 where the virtual line L3 intersects the second light incident surface 51. It protrudes toward the surface 53 (see FIG. 12 described later).

  The lighting module 1 further includes a holding case 3 that houses the light guide plate 7 and the light source 8, and the outer peripheral end surface 6 of the light diffusing plate 2 is arranged in the same plane as the outer peripheral side surface 5 of the holding case 3, or The holding case 6 is disposed outside the outer peripheral side surface 5. The thickness of the outer peripheral side face 5 of the holding case 3 is smaller than the thickness of the outer peripheral end face 6 of the light diffusion plate 2.

  Next, a light path until the light emitted from the LED light source 8 is emitted from the second light emission surface 4 will be described with reference to FIG. FIG. 5 is an explanatory diagram showing a light path until light emitted from the LED light source 8 is emitted from the second light emission surface 4 of the light diffusion plate 2. Part of the light emitted from the LED light source 8 on the left side of the first light source unit 15 enters the light guide plate 7 from the end face 19 of the light guide plate 7 and, for example, as shown by a broken line L1, 7, while traveling toward the right side while being totally reflected by the first light exit surface 32 and the back surface 28, one of which is emitted from the first light exit surface 32. Another part of the light emitted from the LED light source 8 may be emitted from the first light emission surface 32 without being totally reflected by the first light emission surface 32 or the back surface 28.

  The light emitted from the LED light source 8 of the second light source unit 16 on the right side also enters the light guide plate 7 from the right end surface 19 of the light guide plate 7 in the same manner as the left side. The light that has entered the light guide plate 7 proceeds to the left side, and is totally reflected by the first light exit surface 32 and the back surface 28 of the light guide plate 7, and is eventually emitted from the first light exit surface 32.

  Similarly, the light emitted from the LED light source 8 of the third light source unit 17 on the front side also enters the light guide plate 7 from the end face 19 on the front side of the light guide plate 7 like the right side and the left side. . The light that has entered the light guide plate 7 travels to the rear side, and is totally reflected by the first light emission surface 32 and the back surface 28 of the light guide plate 7, and is eventually emitted from the first light emission surface 32. The light emitted from the LED light source 8 of the fourth light source unit 18 on the rear side also enters the light guide plate 7 from the end surface 19 on the rear side of the light guide plate 7 as in the front side. The light that has entered the light guide plate 7 travels to the front side, and is totally reflected by the first light emission surface 32 and the back surface 28 of the light guide plate 7, and is eventually emitted from the first light emission surface 32.

  The light emitted from the first light exit surface 32 of the light guide plate 7 enters the first light entrance surface 53 which is the bottom surface of the concave space 52 of the light diffusion plate 2 and the second light entrance surface 51 of the ridge 26. Then, the light advances through the light diffusion plate 2 and is emitted from the second light emission surface 4. The light diffusion plate 2 contains light scattering particles. Therefore, the light incident on the light diffusion plate 2 is scattered in the light diffusion plate 2, so that the illuminance distribution of the light emitted from the second light emission surface 4 can be made uniform.

  The light emitted from the LED light source 8 is bright at a position close to the LED light source 8 and darkens as the distance increases. However, the lighting module 1 includes the first light source unit 15 on the left side, the second light source unit 16 on the right side, the third light source unit 17 on the front side, and the fourth light source unit 18 on the rear side. ing. Lights emitted from the first plateau unit 15 and the second light source unit 16 facing each other in the left-right direction complement each other, and the third light source unit 17 and the fourth light source unit 18 facing each other in the front-back direction Light emitted from the light guide plate 7 complement each other, and the brightness of the first light emission surface 32 of the light guide plate 7 is made uniform.

  As shown in FIG. 5, a light shielding portion 46 of the light shielding frame 10 is disposed on a peripheral portion 27 of the light guide plate 7 near the LED light source 8. The light shielding portion 46 restricts the light from the LED light source 8 and the peripheral portion 27 to be incident on the ridge portion 26. That is, a part of the second light incident surface 51 is a shielding region B, and a part of the light emitted from the LED light source 8 and traveling toward the second light incident surface 51 is the shielding region B, that is, the light shielding part 46. Shielded by On the other hand, in the incident area C, a part of the light emitted from the first light emitting surface 32 toward the second light incident surface 51 of the ridge 26 is incident.

  Part of the light incident from the second light incident surface 51 of the ridge 26 is totally reflected between the inner side surface 54 and the outer peripheral side 6 of the ridge 26, as shown by a broken line L2. It proceeds while being scattered by the light scattering particles. Then, the light is emitted from the second light emitting surface 4 of the light diffusing plate 2 mainly above the area where the protruding portions 26 are arranged, that is, from the peripheral edge of the second light emitting surface 4 on the side where the LED light sources 8 are arranged. A part of the light incident on the ridge 26 is totally diffused by the inner side surface 54 and the outer peripheral side surface 6 and travels while being scattered by the light scattering particles. Is emitted. The light that has entered the ridge 26 mainly exits from above the position where the ridge 26 is disposed. In this way, the brightness of the second light emitting surface 4 including the peripheral portion is made uniform. Since the light emitted from the second light emitting surface 4 is diffused by the light scattering particles, the intensity and color tone (wavelength of the light) of the emitted light are determined in any direction above the second light emitting surface 53. From the point of view.

  Subsequently, a fixing structure of each part of the lighting module 1 will be described with reference to FIGS. These fixing structures are similar to each other in the first light source unit 15 to the fourth light source unit 18. Therefore, in the following description, the first light source unit 15 on the left side will be exemplified. I do.

  FIG. 6 is a cross-sectional view showing a cut surface cut along a cutting line BB in FIG. The LED light source 8 is mounted on the LED board 35. Then, the circuit connecting portion 37 of the LED board 35 is inserted into the hole 40 provided in the light shielding frame 10, along the back surface side of the lower plate portion 41 of the light shielding frame 35, and the light shielding frame 10 from the frame 9 side. The lower plate portion 41 and the circuit connection portion 37 of the LED board 35 are stacked in this order. Then, the screw 21 as a fixing member is inserted from a through hole provided at a position where the circuit connecting portion 37 and the lower plate portion 41 overlap, and is fixed to the outer peripheral frame portion 30 of the frame 9. At this time, the reflection plate 29 and the light guide plate 7 are arranged between the frame 9 and the light shielding portion 46 before being fixed by the screw 21. The tip of the screw shaft 55 does not penetrate the frame 9.

  As described above, the distance in the direction in which the LED light source 8 approaches the end face 19 is regulated by the position (projection amount) of the protrusion 20 from the end face 19. Further, the board side portion 36 of the LED board 35 on which the LED light source 8 is mounted is restricted by the side portion 45 of the frame 9 from moving to the left of the board side portion 36. On the other hand, the position in the front-back direction of the LED board 35 is regulated by the hole 40 provided in the light shielding frame 10 (see FIG. 10). In addition, a regulating shaft for regulating the position of the LED board 35 may be provided on the frame 9, and a hole for inserting the regulating shaft into the circuit connecting portion 37 may be provided. The light source unit 50 is configured such that the frame 9, the light shielding frame 10, and the LED substrate 35 including the LED light source 8 are integrated by the screws 21. The light source unit 50 includes the light guide plate 7 and the reflection plate 29.

  When the electrical connection between the LED board 35 and the connection board 38 is fixed by soldering, the connection board 38 is connected to the LED board 35 and fixed to the frame 9 by the screws 21 as described above. After the screw 21 is tightened, the holding case 3 is attached to the light source unit 50, and a clearance hole 57 for the screw head 56 is provided in the peripheral edge 11 of the holding case 3. The head 56 of the screw 21 does not protrude from the peripheral portion 11 of the holding case 3 to the outer surface side (back surface side).

  FIG. 7 is a cross-sectional view showing a cut surface cut along a cutting line CC of FIG. Here, a structure in which the light source unit 50 is fixed to the light diffusion plate 2 will be described. As shown in FIG. 6, the light source unit 50 has a configuration in which the frame 9, the light shielding frame 10, and the LED substrate 35 including the LED light source 8 are integrated with the screw 22 as a fixing member. The light source unit 50 inserts the screw shaft portion 60 of the screw 22 into the through hole of the lower plate portion 41 of the light shielding frame 10, the through hole A provided in the frame 9, and the through hole 7A provided in the light guide plate 7, The light diffusion plate 2 is fixed to the ridge 26. A relief hole 59 for a screw head 58 of the screw 22 is provided in the peripheral edge 11 of the holding case 3 so that the screw head 58 does not protrude from the peripheral edge 11 of the holding case 3 to the outer surface side (rear surface side). ing.

  The temperature of the light diffusion plate 2, the light guide plate 7, and the frame 9 is set between the through hole 7 </ b> A provided in the light guide plate 7 and the through hole 9 </ b> A provided in the frame 9 and the screw shaft 60 of the screw 22. A gap is provided such that the difference in expansion and contraction due to the change can be absorbed. As described above, the light diffusion plate 2 and the light guide plate 7 are formed of an acrylic resin, and the frame 9 is formed of an aluminum plate. The coefficient of thermal expansion of the acrylic resin is about three times that of aluminum. Therefore, it is conceivable that the amount of expansion and contraction of each of the light diffusion plate 2, the light guide plate 7, and the frame 9 varies depending on the temperature change, and the lighting module 1 warps with the temperature change. Therefore, a gap is provided between the through hole 7A provided in the light guide plate 7 and the through hole 9A provided in the frame 9 and the screw shaft portion 60 of the screw 22 so as to absorb the difference in the amount of expansion and contraction. I have.

  The tip of the screw shaft portion 60 of the screw 22 has a length such that it is closer to the second light incident surface 51 than the first light incident surface 53 in the protruding portion 26 of the light diffusion plate 2. I have. In FIG. 7, the distal end of the screw shaft portion 60 is substantially on the extension of the first light incident surface 53, but the screw shaft is located on the second light incident surface 51 side as long as the fixing strength of the screw can be obtained. It is preferable to make the length. By doing so, the path of the light emitted from the second light emitting surface 4 while being totally reflected between the outer peripheral side surface 6 and the inner side surface 54 of the light diffusion plate 2 (see FIG. Since the thickness from the light diffusing plate 2 to the second light emitting surface 4 can be sufficiently ensured, there is no hindrance by the screw 22.

  On the other hand, the light guide plate 7 is provided with a plurality of through holes 7A for screw insertion. Since the entire light guide plate 7 serves as a light path, the through-hole 7A may obstruct the light path. However, as described above, in the light guide plate 7, the brightness is complemented by light from the right side on the left side, and the brightness is complemented by light from the left side on the right side. Similarly, the brightness is complemented to each other on the rear side, and the through-hole 7A does not hinder the light path.

  FIG. 8 is a cross-sectional view showing a cut surface cut along a cutting line DD in FIG. 3 and shows a fixing structure at a position where the circuit connecting portion 37 of the LED board 35 is interposed between the holding case 3 and the frame 9. . As described with reference to FIGS. 6 and 7, the light diffusion plate 2, the light guide plate 7, the reflection plate 29, the light shielding frame 10, and the LED board 35 (with the LED light source 8) are integrated by the screws 21 and 22. ing. In this integrated state, the holding case 3 is fixed to the outer peripheral frame 30 of the frame 9 by screws 23 as fixing members. The fixing by the screw 23 is performed in the groove 24 of the holding case 3. The screw head 61 of the screw 23 does not protrude from the peripheral portion 11 of the holding case 3 to the outer surface side (back surface side). The tip of the screw shaft 62 does not penetrate the frame 9.

  FIG. 9 is a cross-sectional view showing a fixing structure at a position where the LED board 35 is not interposed between the holding case 3 and the frame 9. In such a position, the holding case 3 is directly fixed to the outer peripheral frame 30 of the frame 9 at the position where the groove 24 is formed. Therefore, in the fixing structure shown in FIG. 9, the thickness of the peripheral portion 11 is smaller by the thickness of the LED board 35 than in the fixing structure shown in FIG. The screw head 61 of the screw 23 does not protrude from the peripheral edge 11 of the holding case 3 to the outer surface side (back surface side). Further, the tip of the screw shaft portion 62 of the screw 23 does not penetrate the frame 9.

  In one lighting module 1, the fixing structures shown in FIGS. 8 and 9 are mixed. Here, the LED substrate 35 is a flexible substrate and has a thickness of about 0.15 mm, and the circuit connection portion 37 can be easily deformed according to the cross-sectional shape of the groove 24 of the frame 9. On the other hand, the thickness of the holding case 3 is about 0.5 mm, which is extremely thin with respect to a plane area, and is easily bent by increasing the distance between the above two fixing portions with respect to the thickness difference. Is possible. Accordingly, the difference between the position where the LED case 35 is fixed with the LED substrate 35 interposed therebetween and the position where the LED case 35 is fixed without the LED substrate 35 is such that the difference in deformation cannot be recognized even when the holding case 3 is viewed from the back side. Further, since the frame 9 is rigid and does not deform with respect to the holding case 3, it does not affect the light path in the light guide plate 7 and the light diffusion plate 2.

  As described above, each of the screw heads of the screw 21, the screw 22, and the screw 23 does not project to the outer surface side (back side) of the peripheral edge portion 11 of the holding case 3. With this configuration, a clear appearance can be obtained when the lighting module 1 is viewed from the rear surface side, and when the lighting module 1 is mounted on a wall or the like, the screws serving as fixing members do not become an obstacle.

  Next, the connection structure between the LED board 35 and the connection board 38 and the arrangement structure in the thickness direction will be described.

  FIG. 10 is a diagram showing a part of the connection structure between the LED board 35 and the connection board 38. FIG. 10A is a perspective view of the lighting module 1 as viewed from the back side, and FIG. (B) is a cross-sectional view showing a cut surface cut along a cutting line EE of (A), and (C) on the right side of (B) is a cut surface cut along a cutting line FF of (A). FIG. As shown in FIG. 10A, in the LED board 35, a circuit connecting portion 37 is inserted into a hole 40 provided in the light shielding frame 10, and the circuit connecting portion 37 is connected along the back surface of the frame 9. It extends to the intersection with 38. A wiring layer (not shown) is formed on one surface (back surface 35A) and the other surface (front surface 35B) of the LED substrate 35. The LED light source 8 is mounted on the back surface 35A side. The wiring for mounting the LED light source 8 is formed on the wiring layer on the back surface 35A side. A wiring layer (not shown) is also formed on the circuit connecting portion 37 on the surface 35B. In the wiring layer on the front surface 35B side, wiring for making electrical connection with the connection substrate 38 is formed. The wiring layer on the back surface 35A side and the wiring layer on the front surface 35B side are connected by through holes or the like.

  The circuit connecting portion 37 of the LED board 35 has an end portion overlapped with the connecting board 38 and is electrically connected by connecting means. A wiring layer (not shown) is formed on the back surface 38A of the connection substrate 38. In this wiring layer, a wiring for connecting the LED board 35 (LED light source 8) and the circuit section 39, a wiring for connecting the external power supply and the circuit section 39, and the like are formed. As shown in FIG. 10B, the connection between the wiring layer provided on the front surface 35B of the LED substrate 35 and the wiring layer of the connection substrate 38 is electrically connected by solder 64 as connection means. In addition, a resin embossed portion (potting) 65 is provided in a region (see FIG. 10A) indicated by a two-dot chain line for both protection and insulation of the solder connection portion. The connection portion 66 includes the solder connection portion and the resin building portion. The connection part 66 is arranged so as to protrude inside the outer peripheral frame part 30 of the frame 9 (inside the opening part 31). That is, the connection portion 66 is arranged at a position that does not intersect with the frame 9.

  The circuit section 39 is fixed to the back surface 38A of the connection board 38 by a well-known joining means. The circuit section 39 has a circuit element such as an IC chip and a resistance element for controlling lighting of the LED light source 8. These circuit elements may be packaged with a resin mold or the like and joined to the connection board 38, or the circuit elements alone may be joined to the connection board 38. When the circuit section 39 is formed into one package, the terminals of the circuit section 39 are arranged so as to correspond to the wiring provided on the connection board 38, and electrically connected by a joining means such as solder or conductive adhesive. Connecting. When the circuit elements are joined alone, it is preferable to cover each circuit element with a resin mold or the like after the joining. The LED board 35 and the circuit section 39 are connected by a wiring layer provided on the back surface 38A of the connection board 38. That is, the LED light source 8 and the circuit unit 39 are electrically connected. Note that a lead wire (not shown) is connected to the connection board 38, and this lead wire is connected to an external power supply unit so that power can be supplied to the circuit unit 39.

  As shown in FIG. 10C, the circuit section 39 is electrically connected to the back surface 38 </ b> A of the connection board 38, and is disposed at a position that straddles the outer peripheral frame 30 and the opening 31 of the frame 9. I have. When there is no frame 9, the circuit unit 39 is at a position indicated by 39A in the figure, for example. By bringing the circuit portion 39 into contact with the frame 9, the connection board 38 is moved toward the holding case 3 by the amount of intersection H between the circuit portion 39 and the frame 9. That is, the LED board 35 is bent, and the elastic force thereof becomes the contact pressure between the circuit section 39 and the frame 9. The circuit section 39 generates heat by turning on the LED light source 8. However, by bringing the circuit portion 39 into contact with the frame 9 having a high thermal conductivity, the heat of the circuit portion 39 is transmitted from the frame 9 to the holding case 3, and the heat is transferred from the holding case 3 in contact with the holding case 3. I try to escape.

  It is preferable to provide an insulating layer on the entire surface of the LED substrate 35 except for the connection portion with the LED light source 8 and the connection portion with the connection substrate 38 on both the back surface 35A and the front surface 35B. Also, it is preferable to provide an insulating layer on the entire back surface 38A of the connection substrate 38 except for the connection portion with the LED substrate 35 and the connection portion with the circuit portion 39. By providing the insulating layer, short circuit due to contact with another member can be prevented. In addition, it is conceivable that dew condensation occurs depending on the usage environment of the lighting module 1. In such a case, however, providing an insulating layer can prevent a short circuit due to dew condensation.

  In FIG. 10, the connection means between the LED board 35 and the connection board 38 is the solder 64, but can be connected using a well-known connector for a flexible board. Although illustration is omitted, description will be given with reference to FIG. The flexible board connector is mounted at a predetermined position on the back surface 38 </ b> A of the connection board 38. If the tip of the LED board 35 is inserted into the flexible board connector, electrical connection between the LED board 35 and the connection board 38 becomes possible. If a reinforcing board is provided at the insertion portion of the LED board 35 into the flexible board connector, the reliability of connection with the flexible board connector can be increased. The flexible board connector is arranged in the opening 31 of the frame 9 so as not to intersect with the outer peripheral frame 30, similarly to the connection section 66.

2. Effects of Lighting Module FIG. 11 is a diagram illustrating effects of the lighting module according to the embodiment. FIG. 12 is a view for explaining the amount of protrusion of the light shielding portion 46.

    According to the illumination module 1 according to the embodiment, since the light diffusion plate 2 has the inclined surface 14 at the peripheral portion 13 of the second light emitting surface 4, the peripheral portion 13 (the inclined surface 14) of the second light emitting surface 4. It is possible to make the rising angle of the light beam emitted from the upper side upward, as compared with the conventional case (see FIG. 11). That is, the light emitted from the peripheral portion 13 (inclined portion 14) is emitted by the inclined surface 14 in a direction approaching a right angle to the second light emitting surface 4. Thereby, when the second light emission surface 4 is viewed from the emission side, it is possible to suppress a decrease in luminance at the peripheral portion of the illumination module as compared with the related art.

  According to the lighting module 1 according to the embodiment, as a result, when a plurality of lighting modules 1 are juxtaposed, it is possible to configure a large-sized lighting device in which a drop in luminance between the adjacent lighting modules 1 is small. . In addition, according to the lighting module 1 according to the embodiment, since the light diffusion plate 2 has the inclined surface 14 at the peripheral portion 13 of the second light emitting surface 4, even when the lighting module 1 is not lit, the light diffusing plate 2 is located between the adjacent lighting modules 1. A large-sized lighting device in which boundaries are hardly noticeable can be configured.

  Further, according to the illumination module 1 according to the embodiment, since the inclined surface 14 is a convex surface, the light beam emitted from the peripheral portion 13 (the inclined surface 14) of the second light emitting surface 4 becomes closer to the outer peripheral side of the inclined surface 14. Can be increased (see FIG. 11). Thereby, when the second light exit surface 4 is viewed from the exit side, it is possible to further suppress a decrease in luminance at the peripheral portion 13 of the illumination module 1.

  Further, according to the illumination module 1 according to the embodiment, since the inclined surface 14 is a curved surface as described above, the outer peripheral side of the inclined surface 14 is closer to the peripheral portion 13 (the inclined surface 14) of the second light emitting surface 4. Can increase the rising angle of the light beam emitted from (see FIG. 11). Thereby, when the second light exit surface 4 is viewed from the exit side, it is possible to further suppress a decrease in luminance at the peripheral portion 13 of the illumination module 1.

  Further, according to the illumination module 1 according to the embodiment, since the inclined surface 14 is a curved surface as described above, the rising angle of the light beam emitted from the peripheral portion 13 (the inclined surface 14) of the second light emitting surface 4 is determined. Since the change can be made continuous, the change in luminance becomes smooth, and it is possible to make it difficult for a viewer to feel uneven luminance.

  Further, according to the illumination module 1 according to the embodiment, since the ratio of the radius of curvature of the curved surface to the distance between the second light incident surface 51 and the second emission surface 4 of the ridge 26 is 5% or more, The amount of light incident on the curved surface increases (see FIG. 15 (c) described later), and the effect of improving the luminance at the peripheral portion 13 of the illumination module 1 becomes high enough to be visually recognized by a viewer. In addition, since the above ratio is 75% or less, the ratio of the illumination area of the light beam H to the curved surface becomes larger than when the above ratio exceeds 75%, and the optical path length in the convex portion becomes 75%. (See FIG. 22 (c) to be described later), the luminance on the curved surface becomes lower, and the luminance unevenness becomes less conspicuous than when the ratio exceeds 75% (see FIG. 22 (b) to be described later). )reference.).

  Further, according to the illumination module 1 according to the embodiment, the above-described light shielding portion 46 is further provided between the peripheral portion 27 of the first light emitting surface 32 and the second light incident surface 51. For this reason, a part of the light incident on the ridge portion 26 from the second light incident surface 51 is shielded, and the uneven brightness at the peripheral portion can be reduced.

  Further, according to the illumination module 1 according to the embodiment, the light shielding portion 46 does not protrude toward the first incident surface 53 from a position P1 where the virtual line L1 intersects the second light incident surface 51. For this reason, since it is possible to secure a certain amount of light incident from the second light incident surface 51 of the light diffusion plate 2, the peripheral portion 13 of the second light exit surface 4 when viewed from the exit side can be secured. A decrease in luminance can be further suppressed (see FIG. 12).

  Further, according to the illumination module 1 according to the embodiment, the light shielding portion 46 protrudes toward the first incident surface 53 from a position P2 where the virtual line L3 intersects the second light incident surface 51. For this reason, it is possible to block a light beam that travels directly from the light source 8 to the peripheral portion 13, and thus it is possible to reduce unevenness in light amount at the peripheral portion 13 (see FIG. 12).

  In addition, according to the lighting module 1 according to the embodiment, the lighting module 1 further includes the holding case 3 that houses the light guide plate 7 and the light source 8, and the outer peripheral end surface 6 of the light diffusing plate 2 is formed on the outer peripheral side surface of the holding case 3. 5 or the outer side surface 5 of the holding case 6, the outer side surface 5 of the holding case 3 when the lighting module 1 is viewed from the emission surface side. Is difficult to see. Further, when a plurality of lighting modules 1 are juxtaposed, the outer peripheral end surfaces 6 of the adjacent light diffusing plates 2 can be brought into close contact with each other, and it is possible to prevent a dark portion from being generated around each light diffusing plate 4.

  Further, according to the illumination module 1 according to the embodiment, since the thickness of the outer peripheral side surface 5 of the holding case 3 is smaller than the thickness of the outer peripheral end surface 6 of the light diffusion plate 2, the illumination module 1 is viewed obliquely in the emission direction. When holding, the holding case 3 can be made difficult to see.

[Test example]
In this test example, when the inclined surface 14 is a curved surface, the radius of curvature R of the curved surface relative to the distance D (see FIG. 4) between the second light incident surface 51 and the second exit surface 4 of the ridge 26 (see FIG. 4). This is a test example for clarifying how the ratio (see FIG. 4) can be increased to increase the rising angle of the light beam emitted from the peripheral portion 13 of the second light emission surface 4. The test is basically performed on an illumination module having the same configuration as the illumination module 1 according to the embodiment, with respect to the distance D between the second light incident surface 51 and the second exit surface 4 of the ridge 26, the radius of curvature R of the curved surface. The trajectory (progressing state) of light emitted from the peripheral portion 13 of the second light emitting surface 4 and the brightness of the peripheral portion 13 of the second light emitting surface 4 were simulated while changing the ratio of the light emitting surface 4. The simulation was performed using the lighting design analysis software “Light Tools” of Cybernet Systems, Inc. Test examples were performed for the following design examples (design examples 1 to 10).

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Sample name Ratio Remarks Corresponding drawing ---------------------------------------------------
Design Example 10 0% No Inclined Surface FIG.
Design Example 2 With 10% Inclined Surface FIG.
Design Example 3 With 20% Inclined Surface FIG.
Design Example 4 30% Inclined Surface FIG. 17
Design Example 5 With 40% Inclined Surface FIG.
Design Example 6 With 50% Inclined Surface FIG.
Design Example 7 60% Inclined Surface FIG. 20
Design Example 8 With 70% Inclined Surface FIG. 21
Design Example 9 With 75% Inclined Surface FIG. 22
Design Example 10 With 100% Inclined Surface FIG.
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  FIG. 13 is a diagram illustrating a simulation method in the test example. FIG. 13A is a diagram illustrating a region R in which a simulation is performed in the test example, and FIG. 13B is a diagram illustrating light beams emitted from the peripheral edge 13 of the light diffusion plate 2 as a result of the simulation. FIG. 13C is a diagram illustrating a manner of calculating a luminance distribution of light emitted from the peripheral portion 13 of the light diffusion plate 2. FIG. 13 illustrates a simulation method in a test example, taking design example 1 among design examples 1 to 10 as an example.

  14 to 23 are diagrams illustrating simulation results in each of the design examples (design examples 1 to 10). FIGS. 14A to 23A are plan views showing the luminance distribution when the peripheral portion 13 is viewed from a direction (front direction) orthogonal to the second emission surface 4, and FIGS. FIG. 23B is a graph showing a luminance distribution along the line GG when the peripheral portion 13 is viewed from a direction (front direction) orthogonal to the second emission surface 4, and FIGS. FIG. 23C illustrates the subsequent traveling state of the light incident from the second light incident surface 51 and totally reflected by the inner side surface 54 as a light beam H traveling without scattering in the ridge 26. FIG. Note that, since the light beam H is light that travels without scattering inside the convex ridge portion 26, the light beam H is compared with light (scattered light) that travels while scattering inside the convex ridge portion 26 at the same irradiation distance. There is little decrease in light intensity. For this reason, by analyzing the trajectory of the light ray H, it is possible to qualitatively understand the brightness reduction at the peripheral edge of the lighting module.

  In the simulation in the test example, as shown in FIG. 13, the light amount of light emitted from the peripheral portion 13 of the light diffusion plate 2 is measured by a light amount measuring device having a predetermined numerical aperture from a direction orthogonal to the second light emission surface 4. The calculation was performed assuming that it was performed. The numerical aperture of the luminance measuring device was 0.26. In the test example, the region where the simulation is performed is a range of 0 to 3 mm measured from the outer peripheral end surface 6 of the light diffusion plate 2.

  As a result of the test example, as is clear from FIGS. 14 to 23, as the ratio of the radius of curvature of the curved surface to the distance between the second light incident surface 51 and the second emission surface 4 of the ridge 26 increases, the peripheral portion increases. It was found that while the luminance of the peripheral portion 13 was low, the luminance of the peripheral portion 13 was low, and the luminance non-uniformity was small.

  This may be because of the following. That is, the luminance distribution of the peripheral portion 13 includes (a) the light (both the light beam H and the scattered light) that enters from the second light incident surface 51 and exits from the peripheral portion 13 reaches the exit surface of the peripheral portion 13. And the ratio of the irradiation area of the light beam H occupying the inclined surface 14 (the emission ratio of the light beam H on the inclined surface) has a large effect.

  The peripheral portion 13 is a position near the LED light source 8 in the second light emitting surface 4. In addition to this, when the ratio of the radius of curvature increases, the inclined surface 14 approaches the inner side surface 54 and the second light incident surface 51, so that the optical path length in the protruding strip portion of the scattered light and the light beam H decreases, and the inclined surface 14 Light with high light intensity enters.

Therefore, as the ratio of the radius of curvature increases, the luminance of the peripheral portion 13 increases as a whole.
On the other hand, by increasing the ratio of the radius of curvature of the inclined surface 14 in the peripheral portion 13 near the LED light source 8 and shortening the optical path length in the protruding portion of the scattered light and the light beam H, the luminance of the peripheral portion 13 is reduced. The brightness of the second light emission surface 4 inside the second light emission surface 4 tends to be higher than the brightness of the second light emission surface 4, and tends to cause uneven brightness of the second light emission surface 4.

  Further, since the light intensity of the light beam H is higher than that of the scattered light, the ratio of the radius of curvature is increased and the emission ratio of the light beam H on the inclined surface is reduced. It is considered that the brightness tends to be high and uneven brightness tends to occur.

  Therefore, as the ratio of the radius of curvature increases, the luminance of the peripheral portion 13 tends to become non-uniform, and in addition, the luminance distribution of the second light emitting surface 4 tends to cause unevenness in the peripheral portion 13. Conversely, as the ratio of the curvature radii decreases, the luminance of the peripheral portion 13 tends to be uniform, and the luminance distribution of the entire surface of the second light emitting surface 4 including the peripheral portion 13 can be easily uniformed.

  However, the sensory evaluation in the case where the peripheral portion 13 is observed from the front direction does not always correspond to the results of the luminance distribution in the simulation shown in FIGS. 14 (a) and (b) to FIGS. 23 (a) and 23 (b). In the sensory evaluation, when the curvature radius ratio is in the range of 5% or more and 75% or less, improvement and uniformity of the luminance of the peripheral portion 13 are observed, and the luminance distribution of the entire surface of the second light emitting surface 4 is also observed. The uniformity of the luminance including the peripheral portion 13 was achieved.

This is thought to be due to the influence of the angle of the light beam H emitted from the inclined surface 14 with respect to the second light emission surface 4 (the rising angle of the light beam H) as shown in FIGS. 14C to 23C. Can be
That is, by increasing the rising angle of the light beam H (closer to the second light reflecting surface 4 at a right angle), when the viewer observes the second light emitting surface 4 from the front, the luminance of the peripheral portion 13 is reduced. It is considered that the improvement and the reduction of the luminance unevenness are more easily recognized than the simulation results.

  Therefore, by appropriately setting the rising angle of the light beam H in addition to the optical path length in the ridge portion and the emission ratio of the inclined surface of the light beam H, the peripheral portion 13 when the second light emission surface 4 is observed from the front direction. It is considered that the luminance of the second light emitting surface 4 including the peripheral portion 13 can be improved and uniformized, and the uniformity of the luminance can be achieved.

  As described above, from the viewpoint of suppressing the luminance reduction while suppressing the luminance unevenness at the peripheral portion of the illumination module, the curved surface with respect to the interval between the second light incident surface 51 and the second emission surface 4 of the ridge 26 is used. It is found that the ratio of the radius of curvature of is preferably in the range of 5% to 75%. And from the said viewpoint, it turned out that it is more preferable that the said ratio is in the range of 10%-70%, and it is still more preferable that the said ratio is in the range of 20%-60%.

  It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.

(1) In the above-described embodiment, the inclined surface 14 is continuously connected to the second light emitting surface 4 and the outer peripheral side surface 6 to form a curved surface having an arc-shaped cross section. However, the present invention is not limited to this. is not. FIG. 24 is a diagram illustrating a modification of the inclined surface 14. FIG. 24A shows a case where the inclined surface 14 is formed by continuously connecting the second light emitting surface 4 and the outer peripheral side surface 6 to form a curved surface having a circular cross section, and FIG. FIG. 24C shows a case where the two light emitting surface 4 and the outer peripheral side surface 6 are discontinuously connected to each other to form a curved surface having a circular cross section, and FIG. FIG. 24 (d) shows a case where the continuous connection is made to be a curved surface having an elliptical cross section, and FIG. 24 (d) shows a case where the inclined surface 14 is a plane which connects the second light emitting surface 4 and the outer peripheral side surface 6 discontinuously. Show. As shown in FIGS. 24B to 24D, the inclined surface may be a curved surface that discontinuously connects the second light emitting surface 4 and the outer peripheral side surface 6, or the inclined surface may have an elliptical cross section. It may be a curved surface, or the inclined surface may be a linear inclined surface connecting the second light emitting surface 4 and the outer peripheral side surface 6.

(2) In the above embodiment, the case where the lighting module of the present invention is used alone has been described, but the present invention is not limited to this. For example, a plurality of lighting modules of the present invention may be provided, and the plurality of lighting modules may be juxtaposed to be used in the form of a large-sized lighting device. In this case, each lighting module is preferably arranged so that the outer peripheral end surfaces 6 of the light diffusing plate 2 are in contact with each other. Thereby, the boundary between the adjacent lighting modules can be made less noticeable.

DESCRIPTION OF SYMBOLS 1 ... Lighting module, 2 ... Light diffusing plate, 3 ... Holding case, 4 ... Second light emission surface, 5 ... Outer peripheral side (of holding case 3), 6 ... Outer peripheral side (of light diffusing plate 2), 7 ... Conductor Light plate, 7A: through hole, 8: LED light source (light source), 9: frame, 9A: through hole, 10: light shielding frame, 11: peripheral part (of holding case 3), 12: inner part (of holding case 3) ), 13 ... peripheral part (of the second light emitting surface 4), 14 ... inclined part, 15 ... first light source part, 16 ... second light source part, 17 ... third light source part, 18 ... fourth Light source part, 19 ... end face, 20 ... convex part (of light guide plate 7), 21, 22, 23 ... screw, 24 ... groove part (of holding case 3), 26 ... convex part, 27 ... peripheral part (light guide plate 7) ), 28 back surface, 29 reflector plate, 30 outer peripheral frame (of the frame), 31 opening, 32 first light emitting surface, 35 LED board, 6 ... board side part, 37 ... circuit connection part, 38 ... connection board, 39 ... circuit part, 40 ... hole part, 41 ... lower plate part, 45 ... side part, 46 ... upper plate part (light shielding part), 50 ... Light source unit, 51 ... Second light incident surface, 52 ... Concave space, 53 ... First light incident surface, 54 ... Inner side surface, 55,60,62 ... Screw shaft portion, 56,58,61 ... Screw head, 57, 59: escape hole, 64: solder, 65: resin embossed portion, 66: connection portion, 70: lens, L: light beam, L1, L2, L3: virtual line, O1, O2: center, P1, P2: position

Claims (13)

A light guide plate having an end face and a first light exit surface;
A light source arranged along the end face and causing light to enter from the end face,
A first light incident surface on which the light emitted from the first light emitting surface enters, and a first light incident surface on which the light incident from the first light emitting surface exits; A light diffusing plate having two light emitting surfaces,
The light diffusing plate is provided at a position protruding toward the light guide plate and facing the peripheral portion on the end surface side where at least the light source is arranged among the peripheral portions of the first light emission surface of the light guide plate, A ridge having a second light incident surface on which light emitted from the peripheral edge is incident,
The light diffusion plate, at the periphery of the second light emitting surface, have a sloped surface connecting the outer peripheral end face of the light diffusion plate and the second light emitting surface,
The inclined surface is a convex surface,
The inclined surface is a curved surface whose curvature center O1 is located closer to the first light incident surface than the outer peripheral end surface of the light diffusing plate,
An illumination module, wherein a ratio of a radius of curvature of the curved surface to a distance between the second light incident surface and the second light exit surface of the ridge is in a range of 5% to 75% . A light guide plate having an end face and a first light exit surface;
A light source arranged along the end face and causing light to enter from the end face,
A first light incident surface on which the light emitted from the first light emitting surface enters, and a first light incident surface on which the light incident from the first light emitting surface exits; A light diffusing plate having two light emitting surfaces,
The light diffusing plate is provided at a position protruding toward the light guide plate and facing the peripheral portion on the end surface side where at least the light source is arranged among the peripheral portions of the first light emission surface of the light guide plate, A ridge having a second light incident surface on which light emitted from the peripheral edge is incident,
The light diffusion plate, at the periphery of the second light emitting surface, have a sloped surface connecting the outer peripheral end face of the light diffusion plate and the second light emitting surface,
The inclined surface is a convex surface,
The inclined surface is a curved surface whose curvature center O1 is located closer to the first light incident surface than the outer peripheral end surface of the light diffusing plate,
The illumination module, wherein a ratio of a radius of curvature of the curved surface to a distance between the second light incident surface and the second light emitting surface of the ridge is in a range of 10% to 70% . A light guide plate having an end face and a first light exit surface;
A light source arranged along the end face and causing light to enter from the end face,
A first light incident surface on which the light emitted from the first light emitting surface enters, and a first light incident surface on which the light incident from the first light emitting surface exits; A light diffusing plate having two light emitting surfaces,
The light diffusing plate is provided at a position protruding toward the light guide plate and facing the peripheral portion on the end surface side where at least the light source is arranged among the peripheral portions of the first light emission surface of the light guide plate, A ridge having a second light incident surface on which light emitted from the peripheral edge is incident,
The light diffusion plate, at the periphery of the second light emitting surface, have a sloped surface connecting the outer peripheral end face of the light diffusion plate and the second light emitting surface,
The inclined surface is a convex surface,
The inclined surface is a curved surface whose curvature center O1 is located closer to the first light incident surface than the outer peripheral end surface of the light diffusing plate,
The illumination module, wherein a ratio of a radius of curvature of the curved surface to a distance between the second light incident surface and the second light emitting surface of the ridge portion is in a range of 20% to 60% . The lighting module according to any one of claims 1 to 3 ,
A part of light emitted from the peripheral portion of the first light exit surface and incident on the second light incident surface is shielded between the peripheral portion of the first light exit surface and the second light incident surface. A lighting module, further comprising a light shielding portion for performing illumination. The lighting module according to claim 4,
The light shielding portion is closer to the first light incident surface than a position P1 at which a virtual line L1 passing through a center O2 of the curved surface in a circumferential direction and a center of curvature O1 of the curved surface intersects the second light incident surface. A lighting module characterized by not protruding.
The lighting module according to claim 5,
The light-shielding portion is arranged such that a virtual line L3 orthogonal to the second light incident surface and passing through a center O2 of the curved surface in the circumferential direction is closer to the first light than a position P2 where the virtual line L3 intersects the second light incident surface. An illumination module protruding from a side of an incident surface .
The lighting module according to any one of claims 1 to 6 ,
Further comprising a holding case for housing the light guide plate and the light source,
The lighting module according to claim 1, wherein an outer peripheral end surface of the light diffusion plate is disposed in the same plane as an outer peripheral side surface of the holding case, or is disposed outside an outer peripheral side surface of the holding case. The lighting module according to claim 7,
A lighting module, wherein the thickness of the outer peripheral side surface of the holding case is smaller than the thickness of the outer peripheral end surface of the light diffusion plate. A light guide plate having an end face and a first light exit surface;
A light source arranged along the end face and causing light to enter from the end face,
A first light incident surface on which the light emitted from the first light emitting surface enters, and a first light incident surface on which the light incident from the first light emitting surface exits; A light diffusing plate having two light emitting surfaces,
The light diffusing plate is provided at a position protruding toward the light guide plate and facing the peripheral portion on the end surface side where at least the light source is arranged among the peripheral portions of the first light emission surface of the light guide plate, A ridge having a second light incident surface on which light emitted from the peripheral edge is incident,
The light diffusing plate has an inclined surface that connects the second light emitting surface and an outer peripheral end surface of the light diffusing plate at a peripheral portion of the second light emitting surface,
The inclined surface is a convex surface,
The inclined surface is a curved surface whose curvature center O1 is located closer to the first light incident surface than the outer peripheral end surface of the light diffusing plate,
A part of light emitted from the peripheral portion of the first light exit surface and incident on the second light incident surface is shielded between the peripheral portion of the first light exit surface and the second light incident surface. Further comprising a light shielding portion,
The light shielding portion is closer to the first light incident surface than a position P1 at which a virtual line L1 passing through a center O2 of the curved surface in a circumferential direction and a center of curvature O1 of the curved surface intersects the second light incident surface. A lighting module characterized by not protruding.
The lighting module according to claim 9,
The light-shielding portion is arranged such that a virtual line L3 orthogonal to the second light incident surface and passing through a center O2 of the curved surface in the circumferential direction is closer to the first light than a position P2 where the virtual line L3 intersects the second light incident surface. An illumination module protruding from a side of an incident surface . The lighting module according to claim 9 or 10 ,
Further comprising a holding case for housing the light guide plate and the light source,
The lighting module according to claim 1, wherein an outer peripheral end surface of the light diffusion plate is disposed in the same plane as an outer peripheral side surface of the holding case, or is disposed outside an outer peripheral side surface of the holding case. The lighting module according to claim 11 ,
A lighting module, wherein the thickness of the outer peripheral side surface of the holding case is smaller than the thickness of the outer peripheral end surface of the light diffusion plate. A plurality of lighting modules according to any one of claims 1 to 12 ,
The large-sized lighting device, wherein the plurality of lighting modules are arranged so that outer peripheral end surfaces of the light diffusing plate are in contact with each other.