JP2021005501A - Light guide plate illumination device - Google Patents

Abstract

To provide a light guide plate illumination device capable of inhibiting light of a color different from a desired color from leaking outside.SOLUTION: A light guide plate illumination device 1 includes: a light source 20 having a light emitting element and a fluorescent body; a light guide plate 10 having an incidence surface on which light emitted by the light source 20 is made incident, an emission surface (a light extracting structure 12a side) for emitting the light made incident from the incidence surface, and an opposing surface, which is a surface on the opposite side of the emission surface; and a housing 40 for accommodating the light source 20 and the light guide plate 10. An acute angle α formed by a straight line V1 and a virtual surface V2 extending a light emitting surface of the light source 20 is expressed by formula (1), in which t is a thickness of the light guide plate 10, w is a width of the light source 20 parallel to a thickness direction of the light guide plate 10, and z is a distance from the light source 20 to the incidence surface. The housing 40, part of which is provided more on an emission surface side than the straight line V1, includes a light blocking part 42a for blocking the light emitted from a range of the angle α.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a light guide plate lighting device.

As a conventional technique of a light guide plate lighting device, a backlight having a light guide body, a lamp composed of a fluorescent lamp, and a frame body is disclosed (see, for example, Patent Document 1). In Patent Document 1, the side surface of the light guide has a light incident surface, and a plane substantially orthogonal to the light incident surface forms a light emitting surface. A prism sheet is provided on the light emitting surface. Further, the lamp incidents light on the side surface of the light guide body. Further, the frame body is provided at the end of the light guide body, and the lamp and the light guide body are integrated.

Japanese Patent No. 3067717

In the backlight according to Patent Document 1, when a light source having a light emitting element and a phosphor is used instead of the phosphor lamp, the light emitted from the light emitting surface of the light source depends on the length of passage through the phosphor. The light color changes. Normally, the light emitted from the central portion of the light emitting surface becomes light having a high color temperature because the length of light passing through the phosphor is short, but the light emitted from the edge side of the light emitting surface of the light source passes through the phosphor. Due to the long length of light, the light has a low color temperature. The low color temperature light emitted from the surface of the light source at a "shallow angle" becomes leaky light because it is difficult to be incident on the light guide plate, and leaks from between the light source and the light guide plate. That is, in the same configuration as the conventional backlight, even light having a color different from the desired color is emitted to the outside of the luminaire.

Therefore, an object of the present disclosure is to provide a light guide plate lighting device capable of suppressing leakage of light having a color different from a desired color to the outside.

ｔは、前記導光板の厚みであり、ｗは、前記導光板の厚み方向と平行な前記光源の幅であり、ｚは、前記光源から前記入射面までの距離であり、前記筐体は、その一部が前記直線よりも前記出射面側に設けられ、前記角度αの範囲から出射する光を遮光する遮光部を有する。 In order to achieve the above object, one aspect of the light guide plate illuminating device according to the present disclosure is a light source having a light emitting element and a phosphor, an incident surface on which the light emitted by the light source is incident, and an incident surface from the incident surface. A light guide plate having an exit surface for emitting light and a back surface opposite to the emission surface, and a housing for accommodating the light source and the light guide plate are provided, and the light guide plate is the exit surface. And a plurality of light extraction structures formed on at least one of the back surface and for emitting light from the emission surface, the corner portion of the light guide plate defined by the entrance surface and the emission surface, and the light source. The sharp angle α formed by the straight line passing through and the virtual surface extending the light emitting surface of the light source is represented by the following (Equation 1).

t is the thickness of the light guide plate, w is the width of the light source parallel to the thickness direction of the light guide plate, z is the distance from the light source to the incident surface, and the housing is: A part of it is provided on the exit surface side of the straight line, and has a light-shielding portion that blocks light emitted from the range of the angle α.

According to the light guide plate lighting device in the present disclosure, it is possible to prevent light of a color different from the desired color from leaking to the outside.

FIG. 1 is a perspective view showing the overall configuration of the light guide plate lighting device according to the embodiment. FIG. 2 is a cross-sectional view of the light guide plate illumination device according to the embodiment in line II-II of FIG. FIG. 3 is a schematic view illustrating the position of the light-shielding portion in the light guide plate lighting device according to the embodiment. FIG. 4A is an enlarged partially enlarged cross-sectional view of the light source and the light guide plate. FIG. 4B is an enlarged view of the light source and the light guide plate, and is an explanatory view showing the relationship between the angles λ, τ, and θ. FIG. 5 is an explanatory diagram showing an angle β in the light extraction structure at a position closest to the incident surface in the light guide plate. FIG. 6 is an explanatory diagram illustrating the color of light that changes depending on the optical path length of the light emitted from the light emitting element in the light source. FIG. 7 is a cross-sectional view of the light guide plate lighting device according to the first modification of the embodiment. FIG. 8 is a cross-sectional view of the light guide plate lighting device according to the second modification of the embodiment. FIG. 9 is a cross-sectional view of the light guide plate lighting device according to the third modification of the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions of the components, connection forms, etc. shown in the following embodiments are examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, the components not described in the independent claims will be described as arbitrary components.

It should be noted that each figure is a schematic view and is not necessarily exactly illustrated. Further, in each figure, the same reference numerals are given to substantially the same configurations, and duplicate description will be omitted or simplified.

Further, in the following embodiments, expressions such as substantially parallel are used. For example, substantially parallel means not only that they are parallel, but also that they are substantially parallel, that is, they include an error of, for example, about several percent. In addition, substantially parallel means parallel to the extent that the effects of the present disclosure can be achieved. The same applies to other expressions using "abbreviations", expressions using "≈", and expressions using "about".

In the following description, the direction parallel to the direction of the optical axis of the light emitted from the light source is defined as the X-axis direction, and the direction parallel to the longitudinal direction, which is the length direction of the light guide plate illumination device, is defined as the Y-axis direction. And the direction orthogonal to the Y-axis direction is defined as the Z-axis direction.

Hereinafter, the light guide plate lighting device according to the embodiment of the present disclosure will be described.

(Embodiment)
[Structure: Light guide plate lighting device 1]
FIG. 1 is a perspective view showing the overall configuration of the light guide plate lighting device 1 according to the embodiment.

As shown in FIG. 1, the light guide plate lighting device 1 is a lighting device using the light guide plate 10, and is installed on a building material such as a ceiling or a wall, for example. The light guide plate lighting device 1 is a lighting device capable of illuminating a space by irradiating an irradiation surface of a construction material or the like with light. For example, the light guide plate illuminating device 1 is provided at a corner portion on the ceiling side of the wall, and may emit light toward the X-axis plus direction so that the entire irradiation surface of the ceiling to be irradiated with light can be illuminated. it can. Here, the construction material is a member constituting a ceiling, a wall, or the like. Further, in the light guide plate lighting device 1 of the present embodiment, an edge light type light guide plate 10 is used.

FIG. 2 is a cross-sectional view of the light guide plate illumination device 1 according to the embodiment in line II-II of FIG. As shown in FIGS. 1 and 2, the light guide plate lighting device 1 includes a light guide plate 10, a plurality of light sources 20, a substrate 30, a housing 40, a heat radiating portion 50, a reflector 60, and a power supply circuit 70. And.

<Light guide plate 10>
The light guide plate 10 is an optical member that receives light emitted by the light source 20 and guides the light. The light guide plate 10 is a translucent member such as a resin such as acrylic or polycarbonate or glass, but may be formed of any other material as long as it is translucent.

In the present embodiment, the shape of the light guide plate 10 is rectangular in a plan view. The shape of the light guide plate 10 is not limited to a rectangular shape in a plan view, and may be a circular shape, a polygonal shape, or the like in a plan view.

The light guide plate 10 has an incident surface 11, an exit surface 12, and a facing surface 13.

The incident surface 11 is a surface on which light emitted by a plurality of light sources 20 is incident, and is a surface facing the plurality of light sources 20. The incident surface 11 is a surface connected to the edge of the exit surface 12 and the edge of the facing surface 13, and is a side surface of the light guide plate 10 on the negative direction side of the X axis. The incident surface 11 is a plane substantially parallel to the YY plane, and forms a substantially uniform plane.

The exit surface 12 is a surface for emitting light incident from the incident surface 11, that is, light guided by the light guide plate 10, and is a light emission surface for irradiating the irradiation surface with light. For example, the light reflected by the facing surface 13 is emitted from the exit surface 12. The exit surface 12 is a surface of the light guide plate 10 on the Z-axis plus direction side. The exit surface 12 is a plane substantially parallel to the XY plane, and is a substantially uniform plane.

The exit surface 12 is exposed from the opening of the first accommodating portion 41 of the housing 40, which will be described later, in a state where the light guide plate 10 is accommodated in the housing 40. Therefore, the light emitted from the exit surface 12 can be emitted to the outside of the light guide plate illumination device 1.

The facing surface 13 is a surface facing the exit surface 12, that is, a surface opposite to the exit surface 12, and is a surface that reflects the light guided by the light guide plate 10 toward the exit surface 12. The facing surface 13 is a surface of the light guide plate 10 on the Z-axis negative direction side, and faces the bottom portion of the first accommodating portion 41 (the portion of the first accommodating portion 41 on the Z-axis negative direction side). The facing surface 13 is a plane substantially parallel to the XY plane, and forms a substantially uniform plane. The facing surface 13 is an example of the back surface.

Further, a light extraction structure 12a is formed on at least one of the exit surface 12 and the facing surface 13. In the present embodiment, the light extraction structure 12a is formed on the exit surface 12.

When the light extraction structure 12a is formed on the exit surface 12, when the light guiding the light guide plate 10 is incident on the light extraction structure 12a, the light is directly emitted. Further, when the light extraction structure 12a is formed on the facing surface 13, when the light guiding the light guide plate 10 is incident on the light extraction structure 12a, it is indirectly reflected toward the emission surface 12. Emit light.

The light extraction structure 12a has a light distribution control function. The light extraction structure 12a emits light that has guided the light guide plate 10 in a predetermined direction. In the present embodiment, the light extraction structure 12a controls the light distribution so as to emit light in a direction between the X-axis plus direction and the Z-axis plus direction.

The light extraction structure 12a is formed up to a portion near the incident surface 11 on at least one of the exit surface 12 and the facing surface 13. Specifically, the front row of the light extraction structure 12a overlaps with the second accommodating portion 42 when the light guide plate 10 and the second accommodating portion 42 described later are viewed from the Z-axis direction. Here, the front row of the light extraction structure 12a is the position closest to the incident surface 11 among the plurality of light extraction structures 12a, and one or more lights along the Y-axis direction formed on the incident surface 11 side. It is a row of the extraction structure 12a. Further, the front row of the light extraction structure 12a is formed on the X-axis minus direction side of the light-shielding portion 42a of the second accommodating portion 42, that is, is formed up to a deep position of the housing 40.

The light extraction structure 12a is a prism formed by a concave portion or a convex portion, and has a fine structure. The concave portion or convex portion is, for example, a cone such as a cone or a pyramid, a truncated cone such as a truncated cone or a truncated cone, a columnar shape such as a columnar shape or a prismatic shape. In the present embodiment, the light extraction structure 12a is a substantially conical recess and is arranged according to a predetermined rule. The light extraction structure 12a may be excavated by thermal processing such as laser processing on the base material, may be manufactured by mold molding, or may be formed by a cutting device such as a diamond bite. Further, the light guide plate 10 may be manufactured by forming a uniform light extraction structure 12a on at least one of the exit surface 12 and the facing surface 13 and then cutting out a part thereof. In this case, the light guide plate 10 in which the light extraction structure 12a is formed up to the vicinity of the incident surface 11 can be obtained.

<Light source 20>
The plurality of light sources 20 are light emitting modules that are arranged so as to face the incident surface 11 of the light guide plate 10 and emit light toward the incident surface 11 of the light guide plate 10. That is, the plurality of light sources 20 are arranged so that the direction in which light is emitted (optical axis) faces the X-axis plus direction. The light guide plate 10 is arranged in the direction in which the light emitted by the plurality of light sources 20 is emitted (X-axis plus direction).

Further, the plurality of light sources 20 are mounted on the substrate 30. The plurality of light sources 20 are arranged at predetermined intervals in the Y-axis direction. The mounting means that the solder printed on the substrate 30 and the light source 20 mounted on the solder are joined to the substrate 30 via the solder by reflow.

Further, the light source 20 is electrically connected to the power supply circuit 70, and power is supplied from the power supply circuit 70. The light source 20 is turned on and off by being controlled by a control unit (not shown) provided in the power supply circuit 70. Further, the light source 20 is controlled by a control unit provided in the power supply circuit 70 to perform dimming and toning. For example, the light source 20 employs a surface mount type LED element that emits white light by combining a blue LED chip and a yellow phosphor-containing resin.

Each of the plurality of light sources 20 is, for example, an SMD (Surface Mount Device) type LED (Light Emitting Diode) element. Each of the plurality of light sources 20 has a light emitting element 21 which is an LED chip and a phosphor which emits fluorescence by wavelength-converting the light emitted by the light emitting element 21. As the light source 20, a COB (Chip On Board) type light emitting module may be used.

The light emitting element 21 is an LED chip arranged in a resin-molded cavity, and emits light that becomes the light emitted from the light guide plate illumination device 1. The light emitting element 21 is enclosed in a cavity by a resin containing a phosphor. That is, the SMD type LED element is a package type LED element in which the light emitting element 21 is sealed with this resin.

<Board 30>
The substrate 30 is a mounting substrate for mounting a plurality of light sources 20 and a power supply circuit 70, and is, for example, a ceramic substrate, a resin substrate, or an insulatingly coated metal base substrate. The substrate 30 is formed with a pair of electrode terminals (positive electrode terminal and negative electrode terminal) for receiving DC power for causing the light source 20 to emit light from the outside.

The substrate 30 is a rectangular circuit board that is long in the Y-axis direction. The substrate 30 mounts these light sources 20 so that the plurality of light sources 20 are arranged at equal intervals in the Y-axis direction. Further, the substrate 30 mounts the power supply circuit 70, and mounts a plurality of light sources 20 on the Z-axis minus direction side of the power supply circuit 70. Further, the substrate 30 has a plurality of light sources 20 and a power supply circuit 70 mounted on the surface on the positive side of the X-axis. In this way, one substrate 30 has a plurality of light sources 20 and power supply circuits 70 mounted on the same surface.

A part of the substrate 30 is accommodated in the second accommodating portion 42, and the substrate 30 is arranged so as to straddle the first accommodating portion 41 from the second accommodating portion 42. Further, the substrate 30 is arranged up to the vicinity of the ceiling portion 42b1 of the housing 40 (the portion of the second accommodating portion 42 on the Z-axis plus direction side). As a result, the substrate 30 can arrange the power supply circuit 70 vertically above the light source 20.

The substrate 30 is thermally connected to the heat radiating unit 50 so as to dissipate the heat generated by the light source 20 and the power supply circuit 70. In the present embodiment, the substrate 30 is fixed to the heat radiating portion 50 by a fastening portion such as a bolt, and the heat radiating portion 50 is in close contact with the surface of the substrate 30 on the negative side of the X axis. The substrate 30 is supported in the housing 40 by the heat radiating portion 50 in a posture substantially parallel to the YY plane.

<Case 40>
The housing 40 is a housing body that is long in the Y-axis direction, and houses the light guide plate 10, the heat sink, the reflector 60, the light source 20, the substrate 30, and the power supply circuit 70. The housing 40 is in a posture in which the light emitted by the light source 20 is incident on the light guide plate 10 while accommodating the light source 20 and the light guide plate 10, and is in a posture in which the light is emitted from the emission surface 12 of the light guide plate 10. Holds the light source 20 and the light guide plate 10.

The housing 40 is made of a metal material such as aluminum. Therefore, the housing 40 has a light-shielding property. The housing 40 may be made of a material such as resin.

The housing 40 has an L shape when viewed in the Y-axis direction. The housing 40 is formed so as to stand up with respect to the first accommodating portion 41 for accommodating the light guide plate 10 and the light source 20 substantially parallel to the XY plane and the first accommodating portion 41, and the YY plane. It has a second accommodating portion 42 that is substantially parallel.

The first accommodating portion 41 has an opening in which the portion on the Z-axis plus direction side is open, and has a saucer shape or a tray shape that is long in the Y-axis direction. The first accommodating portion 41 forms a space for accommodating the light guide plate 10 through the opening, and supports the light guide plate 10 in a posture substantially parallel to the XY plane. Specifically, the first accommodating portion 41 is provided on the Z-axis minus direction side of the light guide plate 10, and supports the light guide plate 10 with the exit surface 12 of the light guide plate 10 exposed.

The second accommodating portion 42 is a housing 40 that is connected to the first accommodating portion 41 and accommodates the power supply circuit 70 and a part of the substrate 30. The space formed by the second accommodating portion 42 is continuous with the space formed by the first accommodating portion 41.

The second accommodating portion 42 has a shading portion 42a that blocks light leaking from between the incident surface 11 and the light source 20. The light-shielding portion 42a is long in the Y-axis direction and has a bent plate shape. The light-shielding portion 42a is a portion of the second accommodating portion 42 on the X-axis plus direction side in order to block light leaking from between the incident surface 11 and the light source 20, and is a portion substantially parallel to the YY plane. It has a side wall portion 42a1 which is a side wall portion 42a1 and a ceiling portion 42b1 which is a portion of the second accommodating portion 42 on the Z-axis plus direction side and which is substantially parallel to the XY plane. The light-shielding portion 42a may have portions on both sides of the second accommodating portion 42 in the Y-axis direction in order to more reliably block light.

The light-shielding portion 42a will be described with reference to FIG. FIG. 3 is a schematic view illustrating the position of the light-shielding portion 42a in the light guide plate lighting device 1 according to the embodiment.

As shown in FIG. 3, the end edge 42a3 on the negative direction side of the Z axis (hereinafter referred to as the edge 42a3 of the light shielding portion 42a), which is the lower end portion of the light shielding portion 42a, is arranged at a position facing the exit surface 12 and Z. When viewed from the axial direction, it overlaps with the light extraction structure 12a described later. The edge 42a3 of the light-shielding portion 42a is a part of the side wall portion 42a1 of the light-shielding portion 42a. Further, the edge 42a3 of the light-shielding portion 42a is provided in the plus direction of the X-axis with respect to the incident surface 11 of the light guide plate 10. Specifically, when the housing 40 and the light guide plate 10 are viewed in the Y-axis direction, the edge 42a3 of the light-shielding portion 42a is the corner portion P1 of the light guide plate 10 defined by the incident surface 11 and the light emitting surface 12. It is provided on the exit surface 12 side of the straight line V1 passing through the light source 20, and is provided so as to block light emitted from the entire range of the angle α as shown in FIGS. 3 and 4A. FIG. 4A is an enlarged partially enlarged cross-sectional view of the light source 20 and the light guide plate 10. Further, in FIG. 4A, the power supply circuit 70, the heat radiating portion 50, and the like are omitted for convenience.

The acute angle α formed by the straight line V1 and the virtual surface V2 extending the light emitting surface of the light source 20 is represented by the following (Equation 1).

t is the thickness of the light guide plate 10 in the Z-axis direction. w is the width of the light source 20 parallel to the thickness direction (Z-axis direction) of the light guide plate 10. z is the distance from the light source 20 to the incident surface 11.

Further, the light-shielding portion 42a does not exist in the range of the angle β when the housing 40 and the light guide plate 10 are viewed in the Y-axis direction, and the main emission direction of light from the light extraction structure 12a (hereinafter referred to as the main direction). ) Is provided on the incident surface 11 side. The main direction is the axial direction having the strongest light intensity in the directivity of the light emitted from the light extraction structure 12a. The main direction is an example of the light emission direction.

The angle β will be further described with reference to FIGS. 4B and 5. FIG. 4B is an enlarged view of the light source 20 and the light guide plate 10, and is an explanatory view showing the relationship between the angles λ, τ, and θ. FIG. 5 is an explanatory view showing an angle β of the light extraction structure 12a at a position closest to the incident surface 11 on the light guide plate 10.

As shown in FIGS. 4A, 4B and 5, the angle β is the distance x1 (= emission start offset amount) from the incident surface 11 to the specified position on the exit surface 12 and the position closest to the incident surface 11. At any of the distances x2 of one or more arranged light extraction structures 12a, the starting point is the distance far from the incident surface 11, and the main direction and the exit surface emitted from the exit surface 12. It is a sharp angle formed by 12. As shown in FIGS. 4A and 5, in the present embodiment, the angle β exemplifies an acute angle angle formed by the main direction emitted from the front row of the light extraction structure 12a and the exit surface 12. The angle β assumes a case where light having a Lambert light distribution is incident on the incident surface 11. Further, the region from the incident surface 11 to the specified position is a non-light emitting region. That is, in the example of FIG. 4A, the region at a distance x1 from the incident surface 11 is the non-light emitting region. Further, in the emission surface 12, in the region other than the non-light emitting region (on the X-axis plus direction side from the point at the distance x1 from the incident surface 11), the light extraction structure 12a is provided to emit light whose light distribution is controlled. be able to. That is, the exit surface 12 of the light guide plate 10 has a non-light emitting region formed along the incident surface 11 side and a light emitting region other than the non-light emitting region. The distance x1 is shown by (Equation 3) described later.

As shown in FIGS. 4B and 5, the angle β is represented by the following (Equation 2).

τ is an acute-angled angle formed by the extension line of the arbitrary surface 12a1 and the exit surface 12 in the light extraction structure 12a. The arbitrary surface 12a1 is the inner peripheral surface of the conical light extraction structure 12a in the present embodiment. In the present embodiment, the angle τ is 15 ° or more and 55 ° or less. Further, in the present embodiment, β≈16 °.

Further, λ is the normal direction of the arbitrary surface 12a1 in the light extraction structure 12a and the maximum angular light emission direction in which the light emitted by the light extraction structure 12a has the maximum angle with respect to the emission surface 12. It is an acute-angled angle formed by the angular light emission direction. The maximum angular light emission direction is the emission direction of the light having the largest angle with respect to the emission surface 12 in the directivity of the light emitted from the light extraction structure 12a. The angle formed by the maximum angle light emission direction and the emission surface 12 is about 2β.

As shown in FIG. 4A, the distance x1 is represented by the following (Equation 3).

In this embodiment, x1≈1.35t. Assuming that the refractive index of air is 1 and the refractive index of the light guide plate 10 is 1.5, the critical angle θ is about 42 ° using Snell's law. As a result, the distance x1 is derived.

That is, the edge 42a3 of the light-shielding portion 42a is on the exit surface 12 side of the straight line V1 passing through the corner portion P1 of the light guide plate 10 defined by the incident surface 11 and the exit surface 12 and the light source 20. It is located on the incident surface 11 side of the light guide plate 10 with respect to the main direction, which is the main emission direction of the light emitted from the surface 12. That is, since almost no light is emitted from the non-light emitting region between the incident surface 11 and the distance x1, FIGS. 3 and 3 are between the straight line V1 and the main direction (which may be the maximum angular light emitting direction). Even if the light-shielding portion 42a is arranged in the region H indicated by the hatching of dots at narrow intervals of 4A, the light-shielding portion 42a does not block the light whose light distribution is controlled (particularly the light in the main direction) emitted from the light emitting region. For example, if x1> x2, almost no light whose light distribution is controlled is emitted from one or more light extraction structures 12a arranged at positions closest to the incident surface 11. Further, for example, even if x2> x1, the light-shielding portion 42a does not block the light whose light distribution is controlled from one or more light extraction structures 12a arranged at the position closest to the incident surface 11. In this way, by adopting the distance of the distance x1 and the distance x2 that is farther from the incident surface 11, the light-shielding portion 42a shields the light leaking from between the light source 20 and the light guide plate 10 and at the same time. The light distribution controlled light emitted in the main direction is not blocked.

The inner surface of the light-shielding portion 42a (the surface on the power supply circuit 70 side) may have a property of absorbing light. Further, a light absorbing member for absorbing light may be provided on the inner surface of the light shielding portion 42a.

As shown in FIGS. 1 and 2, when the light guide plate lighting device 1 is installed on the wall so that the exit surface 12 of the light guide plate 10 faces the ceiling, the second accommodating portion 42 is the first accommodating portion 41. It is located vertically above (an example in the plus direction of the Z axis). Therefore, in the second accommodating portion 42, the power supply circuit 70 can be arranged vertically above the light guide plate 10, the light source 20, and the light shielding portion 42a.

<Heat dissipation part 50>
The heat radiating portion 50 is a metal member formed in an L shape when viewed in the Y-axis direction. The heat radiating portion 50 is supported inside the housing 40 in a state of being housed in the housing 40.

The heat radiating portion 50 is housed in the accommodating portion and has a flat plate portion 51 and a rising portion 52.

The flat plate portion 51 is substantially parallel to the XY plane and has a length equivalent to the length of the substrate 30 in the Y-axis direction. The flat plate portion 51 is fixed to the light guide plate 10 by fastening portions such as bolts via a spacer and a reflector 60. That is, the fastening portion is screwed by inserting the light guide plate 10, the reflector 60, and the flat plate portion 51. The fastening portion may also be fastened to the bottom portion of the first accommodating portion 41.

The rising portion 52 is a portion of the flat plate portion 51 that rises in the positive direction of the Z axis from the edge on the negative side of the X axis. The rising portion 52 is substantially parallel to the YZ plane, and has a length equivalent to the length in the longitudinal direction (Y-axis direction) of the substrate 30 in the Y-axis direction. The substrate 30 is in close contact with the surface of the rising portion 52 on the X-axis positive direction side. The rising portion 52 supports the substrate 30 by fastening portions such as bolts. The rising portion 52 has the same size as the substrate 30, and is arranged up to the vicinity of the ceiling portion 42b1 of the housing 40.

The heat radiating unit 50 is a metal material having high thermal conductivity such as aluminum (Al), copper (Cu) or iron (Fe) in order to efficiently dissipate the heat generated by the light source 20 and the power supply circuit 70 to the housing 40. May be used as a main component. Further, the heat radiating portion 50 is not limited to the metal one, and may be formed by using a resin material having a high thermal conductivity.

The heat radiating unit 50 is also thermally connected to the housing 40, and the housing 40 also serves as a heat sink.

<Reflector 60>
The reflector 60 is a reflective material that reflects the light emitted from the light guide plate 10 to the facing surface 13 toward the exit surface 12. The reflector 60 is provided so as to cover at least a part of the facing surface 13 of the light guide plate 10. In the reflector 60, the surface facing the facing surface 13 is processed to reflect light, for example, a mirror surface. The reflector 60 may not be provided on the light guide plate 10, and is not an essential component of the light guide plate illumination device 1.

The reflector 60 is formed of, for example, a metal member such as aluminum. The reflector 60 may be a resin material to which a metal film is added, or may be formed of a white resin material or a white-painted metal material.

<Power supply circuit 70>
The power supply circuit 70 is housed in the housing 40 and controls lighting to turn on and off the light source 20. The power supply circuit 70 is a lighting circuit in which a plurality of electronic components are mounted on the substrate 30. The power supply circuit 70 generates driving power for causing the plurality of light sources 20 to emit light. For example, the power supply circuit 70 has an AC / DC converter and the like. The power supply circuit 70 converts AC power supplied from a commercial power source into DC power, and supplies the converted DC power to the light source 20. As a result, the light source 20 emits light.

Further, the power supply circuit 70 is arranged vertically above the light source 20. That is, the power supply circuit 70 is housed in the second accommodating portion 42 of the housing 40, and is arranged on the Z-axis plus direction side with respect to the edge 42a3 of the light guide plate 10, the light source 20, and the light shielding portion 42a. The power supply circuit 70 is arranged near the ceiling portion 42b1 of the housing 40.

The power supply circuit 70 may be mounted on the surface of the substrate 30 opposite to the plurality of light sources 20.

[Action effect]
Next, the operation and effect of the light guide plate lighting device 1 in the present embodiment will be described.

As described above, the light guide plate illumination device 1 according to the present embodiment has a light source 20 having a light emitting element 21 and a phosphor 22, an incident surface 11 on which the light emitted by the light source 20 is incident, and an incident surface 11. It is provided with a light guide plate 10 having an exit surface 12 for emitting the emitted light, a facing surface 13 which is a surface opposite to the emission surface 12, and a housing 40 for accommodating the light source 20 and the light guide plate 10. Further, the light guide plate 10 is formed on at least one of the exit surface 12 and the facing surface 13, and has a plurality of light extraction structures 12a for emitting light from the exit surface 12. Further, the acute angle α formed by the straight line V1 passing through the corner portion P1 of the light guide plate 10 defined by the incident surface 11 and the exit surface 12 and the light source 20 and the virtual surface V2 extending the light emitting surface of the light source 20 is , It is represented by the following (Equation 4).

t is the thickness of the light guide plate 10. w is the width of the light source 20 parallel to the thickness direction of the light guide plate 10. z is the distance from the light source 20 to the incident surface 11. A part of the housing 40 is provided on the exit surface 12 side of the straight line V1 and has a light-shielding portion 42a that blocks light emitted from the range of the angle α.

For example, as shown in FIG. 6, when the light source 20 having the light emitting element 21 and the phosphor 22 is used for the light guide plate illumination device 1, the light emitted from the light emitting surface of the light source 20 passes through the phosphor 22. The light color changes depending on the length. The light emitted from the central portion of the light emitting surface 20a has a high color temperature because the distance from the light emitting element 21 to the light emitting surface 20a is short, that is, the distance passing through the phosphor 22 is short and the light includes light that is not wavelength-converted. .. On the other hand, the light emitted from the edge side of the light emitting surface 20a has a longer distance from the light emitting element 21 to the light emitting surface 20a than the optical path length of the light emitted from the central portion of the light emitting surface 20a, that is, passes through the phosphor 22. Since the distance is long and most of the light is wavelength-converted, the color temperature is low. FIG. 6 is an explanatory diagram illustrating the color of light that changes depending on the optical path length of the light emitted from the light emitting element 21 in the light source 20.

Such low color temperature light may become leak light without being incident on the incident surface 11 of the light guide plate 10. Since the leaked light has a low color temperature, it has a different color from the high color temperature light incident on the incident surface 11 of the light guide plate 10. When the light having a low color temperature leaks from the light guide plate illuminating device 1, the color of the light irradiated to the irradiated surface cannot be balanced, and the appearance of the irradiated surface deteriorates.

However, according to the present embodiment, the light-shielding portion 42a is provided on the exit surface 12 side of the straight line V1 passing through the corner portion P1 of the light guide plate 10 defined by the incident surface 11 and the exit surface 12 and the light source 20. Therefore, it is possible to block the low color temperature light emitted from between the light source 20 and the incident surface 11. Therefore, the light guide plate lighting device 1 suppresses the emission of light having such a low color temperature from the housing 40.

Further, since light having a high color temperature is incident on the incident surface 11 of the light guide plate 10, light having a high color temperature, that is, desired light is emitted from the exit surface 12 of the light guide plate 10.

Therefore, according to the light guide plate lighting device 1, it is possible to prevent light having a color different from the desired color from leaking to the outside of the light guide plate lighting device 1.

Further, the light guide plate illuminating device 1 according to the present embodiment is located on the exit surface 12 at a distance x1 from the incident surface 11 to a specified position and at a position closest to the incident surface 11 among the plurality of light extraction structures 12a. At any of the distances x2 to one or more arranged light extraction structures 12a, the starting point is the distance far from the incident surface 11, and the light emitted from the emitting surface 12 is emitted. The sharp angle β formed by the exit surface 12 is represented by the following (Equation 5).

τ is an acute-angled angle formed by an extension line of an arbitrary surface 12a1 constituting one or more light extraction structures 12a and an emission surface 12. λ is the normal direction of any surface 12a1 constituting one or more light extraction structures 12a, and the maximum angle light emission at which the light emitted by one or more light extraction structures 12a has the maximum angle with respect to the emission surface 12. It is an acute angle between the directions. Further, the distance x1 is represented by the following (Equation 6).

The light-shielding portion 42a is provided on the incident surface 11 side of the emitting direction of the light emitted from the emitting surface 12 at the position serving as the starting point of the angle β.

In recent years, for example, there is a desire to irradiate the light emitted from the light guide plate as far as possible. On the other hand, from the viewpoint of design, there is a demand to reduce the total width (width in the X-axis direction) of the light guide plate lighting device. Therefore, if the width of the light guide plate in the X-axis direction is reduced, the overall width of the light guide plate lighting device is reduced, but the light guide length of the light guide plate is shortened, so that the control light controlled by the light extraction structure of the light guide plate is reduced. The ratio of is reduced. Therefore, it is desired to secure as much light (light whose light distribution is controlled) as far as possible from the light emitting surface of the light guide plate. Therefore, it is desired to secure the amount of light emitted from the exit surface by providing a light extraction structure near the incident surface of the light guide plate. Further, since the light emitted from the light extraction structure is light whose light distribution is controlled, it is not desired to block such light in the light blocking portion as much as possible. In other words, we want to make effective use of light whose light distribution is controlled.

Therefore, in the present embodiment, the light is incident from the direction of the light emitted from the light extraction structure 12a, that is, the direction that is half the angle between the maximum angle light emission direction and the emission surface 12 (that is, the main direction). A light-shielding portion 42a is arranged on the surface 11 side. In the main direction emitted from the light extraction structure 12a, the intensity of the light from the light extraction structure 12a is the strongest. Therefore, in the light guide plate lighting device 1, since the light shielding portion 42a does not block the strong light (for example, the light in the main direction) emitted from the light extraction structure 12a, the light is effectively emitted from the light emitting surface 12 of the light guide plate 10. Can be emitted.

Further, in the light guide plate illuminating device 1 according to the present embodiment, since almost no light is emitted from the non-light emitting region between the incident surface 11 and the distance x1, it is between the straight line V1 and the main direction in FIG. 4A. Even if the light-shielding portion 42a is arranged in the region H, the light-shielding portion 42a does not block the light whose light distribution is controlled (particularly the light in the main direction) emitted from the light emitting region. For this reason, since the distance x1 and the distance x2 that are farther from the incident surface 11 are adopted, the light-shielding portion 42a has a low color temperature emitted from between the light source 20 and the incident surface 11. Not only does it block light, it does not block light emitted from the exit surface 12 (particularly light in the main direction).

Further, in the light guide plate lighting device 1 according to the present embodiment, x1 ≈ 1.35 t.

Even in this case, the light guide plate illuminating device 1 can more reliably and efficiently emit the light guided by the light guide plate 10 from the exit surface 12.

Further, in the light guide plate lighting device 1 according to the present embodiment, β≈16 °.

According to this, since the light-shielding portion 42a is arranged so as not to block the light emitted from the light emitting region, the light guide plate illuminating device 1 emits the light emitted from the light guide plate 10 more efficiently from the emission surface 12. Can be made to.

Further, in the light guide plate lighting device 1 according to the present embodiment, the plurality of light extraction structures 12a are formed on the exit surface 12.

According to this, since the light extraction structure 12a emits the direct light that guides the light guide plate 10, the light that guides the light guide plate 10 is emitted as compared with the case where the light extraction structure 12a is formed on the facing surface 13. It can be efficiently emitted from the exit surface 12.

Further, in the light guide plate lighting device 1 according to the present embodiment, the plurality of light extraction structures 12a are prisms formed by recesses or protrusions. The acute angle τ formed by the extension line of the arbitrary surface 12a1 constituting the plurality of light extraction structures 12a and the exit surface 12 is (i) 15 ° or more and 55 ° or less.

For example, when the angle τ is less than (ii) 15 °, the extraction efficiency of the light emitted from the light extraction structure tends to decrease. On the other hand, when the angle τ is (iii) 55 ° or more, the main direction of the light emitted from the exit surface approaches the normal direction of the exit surface of the light guide plate, so that the light distribution ratio in the X-axis plus direction decreases.

However, in the present embodiment, the extraction efficiency of the light emitted from the light extraction structure 12a in the plus direction of the X-axis can be increased as compared with the case where the angle τ is (ii) or (iii). This is because, for example, when the light extraction structure 12a is a conical recess and the opening diameter is the same, the light extraction structure 12a is deeper in (i) than in the case where the angle τ is (ii). The area of 12 is increased. Therefore, the light that guides the light guide plate 10 is likely to enter the light extraction structure 12a. Further, since the main direction is tilted in the plus direction of the X-axis in (i) than in the case where the angle τ is (iii), light in the target shallow direction is more likely to be emitted. The shallow direction is a direction in which the angle β is inclined in the plus direction of the X axis so as to approach the exit surface 12 side.

Further, the light guide plate illumination device 1 according to the present embodiment further includes a reflector 60 provided on the facing surface 13 and reflecting light that guides the light guide plate 10.

According to this, the light that guides the light guide plate 10 and is totally reflected by the light emitting structure 12a and emitted from the facing surface 13 is reflected toward the emitting surface 12 by the reflecting plate 60, and thus is reflected from the facing surface 13. The emitted light can be emitted from the exit surface 12 side. That is, in this light guide plate lighting device 1, it is possible to suppress a decrease in the amount of light emitted from the exit surface 12 as compared with the case where the reflector 60 is not provided on the facing surface 13. In other words, in this light guide plate illumination device 1, light can be efficiently emitted from the emission surface 12.

Further, the light guide plate lighting device 1 according to the present embodiment is further housed in a housing 40 and includes a power supply circuit 70 for controlling lighting of the light source 20. The power supply circuit 70 is arranged vertically above the light source 20.

According to this, by arranging the power supply circuit 70 vertically above the light source 20, the width of the light guide plate illuminating device 1 in the X-axis direction is larger than that in the case where the power supply circuit 70 is arranged on the back surface side of the light source 20. It can be suppressed from becoming.

Further, since the power supply circuit 70 is housed in the housing 40, it becomes difficult to visually recognize the power supply circuit 70 from the outside of the light guide plate lighting device 1. Therefore, the appearance of the light guide plate lighting device 1 is unlikely to deteriorate.

Further, the light guide plate lighting device 1 according to the present embodiment further includes a substrate 30 on which the light source 20 and the power supply circuit 70 are mounted.

According to this, since the light source 20 and the power supply circuit 70 are shared by one substrate 30, it is not necessary to separately provide the substrate 30 of the light source 20 and the substrate 30 of the power supply circuit 70. The light guide plate lighting device 1 can be downsized by this amount.

(Modification 1 of the embodiment)
[Constitution]
The light guide plate lighting device 1 according to this modification will be described with reference to FIG. 7.

FIG. 7 is a cross-sectional view of the light guide plate lighting device 1 according to the first modification of the embodiment.

Unless otherwise specified, the configuration of the light guide plate illumination device 1 of this modification is the same as that of the embodiment, and the same configuration is designated by the same reference numerals and detailed description of the configuration will be omitted.

In this modification, as shown in FIG. 7, when the housing 140 is viewed in the Y-axis direction, the light source 20 is a part of the light-shielding portion 142a of the second accommodating portion 42 in the housing 140. And extends closer to the incident surface 11. That is, the side wall portion 142a1 of the light-shielding portion 142a is curved from the ceiling portion 142b1 of the light-shielding portion 142a so as to cover the power supply circuit 70, and is in the vicinity of the light source 20 and the incident surface 11 so as to approach the light source 20 and the incident surface 11. It is placed over.

When the housing 140 and the light guide plate 10 are viewed from the Z-axis direction, the edge 142a3 of the end portion of the side wall portion 142a1 of the light shielding portion 142a may overlap with the front row of the light extraction structure 12a, and this row may overlap. It does not have to overlap with. That is, in this case, the edge 142a3 of the side wall portion 142a1 may be arranged on the incident surface 11 side or the X-axis plus direction side from this row.

As described above, in the light guide plate lighting device 1 according to the present embodiment, the housing 140 further includes the first accommodating portion 41 accommodating the light guide plate 10 and the substrate 30 in a state of being erected with respect to the exit surface 12. It has a second accommodating portion 42 for accommodating at least a part of the above. Further, the light-shielding portion 142a is formed in the second accommodating portion 42. Then, the light-shielding portion 142a extends so that a part of the light-shielding portion 142a approaches the light source 20 and the incident surface 11.

According to this, the end portion of the light-shielding portion 142a can be arranged in a state of being close to the light source 20 and the incident surface 11. Therefore, it becomes difficult to block the light whose light distribution is controlled to be emitted from the front row of the light extraction structure 12a. Therefore, the light emitted from the exit surface 12 of the light guide plate 10 can be used more effectively as the illumination light. Further, the light-shielding portion 142a can block the leaked light that is not incident on the light guide plate 12 by the light from the light source 20 and make the power supply circuit 70 difficult to see from the outside.

(Modification 2 of the embodiment)
[Constitution]
The light guide plate lighting device 1 according to this modification will be described with reference to FIG.

FIG. 8 is a cross-sectional view of the light guide plate lighting device 1 according to the second modification of the embodiment.

Unless otherwise specified, the configuration of the light guide plate illumination device 1 of this modification is the same as that of the embodiment, and the same configuration is designated by the same reference numerals and detailed description of the configuration will be omitted.

As shown in FIG. 8, the light guide plate 10 used in the light guide plate illumination device 1 of this modification has a light guide plate 10 that becomes thinner as the distance from the incident surface 11 increases. That is, the thickness of the light guide plate 10 becomes thinner from the incident surface 11 toward the plus direction of the X-axis. Therefore, the edge of the light guide plate 10 on the plus direction side of the X axis is tapered. When the light guide plate lighting device 1 is viewed in the minus direction of the X axis, the edge of the light guide plate 10 on the plus direction of the X axis overlaps with the first accommodating portion 41. Therefore, the first accommodating portion 41 suppresses the emission of light that becomes glare from the edge of the light guide plate 10 on the plus direction side of the X axis.

As described above, in the light guide plate lighting device 1 according to the present embodiment, the thickness of the light guide plate 10 becomes thinner as the distance from the incident surface 11 increases.

For example, the amount of light emitted from the exit surface of the light guide plate tends to decrease as the distance from the incident surface increases.

However, according to the present embodiment, as the distance from the incident surface 11 increases, light is emitted from the exit surface 12 and the facing surface 13 at a "shallow angle" due to the angle formed by the exit surface 12 and the facing surface 13 of the light guide plate 10. Exit. The "shallow angle" is an angle between the main direction and the exit surface 12 when the angle β is tilted in the plus direction of the X axis so as to approach the exit surface 12. The light incident from the incident surface 11 toward the exit surface 12 becomes light at a "shallow angle" toward the main direction and is emitted from the exit surface 12. Further, the light emitted from the facing surface 13 by the light guiding the light guide plate 10 is reflected by the reflector 60 and becomes light having a "shallow angle" toward the main direction and is emitted from the exit surface 12. Therefore, as compared with the case of the light guide plate 10 in which the exit surface 12 and the facing surface 13 are parallel to each other, light at a “shallow angle” can be easily extracted from the light guide plate 10. That is, as compared with the case of the light guide plate 10 in which the exit surface 12 and the facing surface 13 are parallel to each other, it becomes easier to emit light in the main direction or at a "shallow angle". Therefore, the light guide plate illumination device 1 can irradiate light to an irradiation surface farther away.

(Modification 3 of the embodiment)
[Constitution]
The light guide plate lighting device 1 according to this modification will be described with reference to FIG.

FIG. 9 is a cross-sectional view of the light guide plate lighting device 1 according to the third modification of the embodiment.

Unless otherwise specified, the configuration of the light guide plate illumination device 1 of this modification is the same as that of the embodiment, and the same configuration is designated by the same reference numerals and detailed description of the configuration will be omitted.

In this modification, for convenience, a configuration in which a light guide plate 10, a plurality of light sources 20, a substrate 30, a housing 140, a heat radiating portion 50, a reflector 60, and a power supply circuit 70 are integrated is referred to as a luminaire main body. In this modification, as shown in FIG. 9, the luminaire main body is housed in the housing 140. In the luminaire body, the exit surface 12 of the light guide plate 10 is inclined with respect to the XY plane, and the mounting surface of the substrate 30 is inclined with respect to the YY plane, that is, the optical axis emitted by the light source 20 is It is held in the housing 140 in a state of being housed in the housing 140 so as to be inclined with respect to the X-axis direction. Here, the mounting surface of the substrate 30 is the surface on the positive side of the X-axis, and is the surface on which the light source 20 and the power supply circuit 70 are mounted.

In this modification, the facing surface 13 is inclined with respect to the XY plane. Therefore, the reflector 60 is also inclined with respect to the XY plane.

The exit surface 12, the facing surface 13, and the reflector 60 are inclined downward toward the opposite side (X-axis plus direction) of the light guide plate 10 from the incident surface 11.

As described above, in the light guide plate lighting device 1 according to the present embodiment, the light guide plate 10 is supported by the housing 140 in an inclined posture with respect to the irradiation surface irradiated with the light emitted from the emission surface 12. To.

According to this, since the exit surface 12 of the light guide plate 10 is inclined with respect to the irradiation surface, the light guide plate illumination device 1 can irradiate light to a farther irradiation surface.

(Other variants)
The light guide plate lighting device according to the present disclosure has been described above based on the embodiments and the modifications 1 to 3 of the embodiments. However, the present disclosure describes the above-described embodiments and modifications 1 of the embodiments. It is not limited to ~ 3.

For example, in the light guide plate lighting devices according to the above-described embodiments and modifications 1 to 3 of the embodiments, the density per unit area of the light extraction structure formed on at least one of the exit surface and the facing surface is determined. It may become higher as the distance from the light guide control surface increases.

It should be noted that the above-described embodiments and modifications 1 to 3 of the embodiments can be obtained by performing various modifications that can be conceived by those skilled in the art, and the embodiments and embodiments within the scope of the present disclosure. The present disclosure also includes a form realized by arbitrarily combining the components and functions in the first to third modifications of the form.

1 Light guide plate lighting device 10 Light guide plate 11 Incident surface 12 Exit surface 12a Light extraction structure 13 Facing surface (back surface)
20 Light source 21 Light emitting element 22 Fluorescent material 30 Substrate 40, 140 Housing 41 First accommodating portion 42 Second accommodating portion 42a, 142a Light-shielding portion 60 Reflector 70 Power supply circuit P1 Corner

Claims (12)

A light source having a light emitting element and a phosphor,
A light guide plate having an incident surface on which the light emitted by the light source is incident, an exit surface on which the incident light is emitted from the incident surface, and a back surface which is a surface opposite to the exit surface.
A housing for accommodating the light source and the light guide plate is provided.
The light guide plate is formed on at least one of the exit surface and the back surface, and has a plurality of light extraction structures for emitting light from the emission surface.
The acute angle α formed by the straight line passing through the corner portion of the light guide plate defined by the incident surface and the exit surface and the light source and the virtual surface extending the light emitting surface of the light source is as follows (Equation). Represented by 1)

t is the thickness of the light guide plate, and is
w is the width of the light source parallel to the thickness direction of the light guide plate.
z is the distance from the light source to the incident surface.
A light guide plate illuminating device having a part of the housing provided on the exit surface side of the straight line and having a light-shielding portion that blocks light emitted from the range of the angle α. The distance x1 from the incident surface to the specified position on the exit surface, and the distance x2 to one or more light extraction structures arranged at positions closest to the incident surface among the plurality of light extraction structures. At any of these distances, the angle β of the sharp angle formed by the emission direction of the light emitted from the emission surface and the emission surface, starting from the distance far from the entrance surface, is as follows (Equation). Represented by 2)

τ is an acute-angled angle formed by an extension line of an arbitrary surface constituting the one or more light extraction structures and the emission surface.
λ is the normal direction of any surface constituting the one or more light extraction structures and the maximum angle light emission direction in which the light emitted by the one or more light extraction structures has the maximum angle with respect to the emission surface. It is an acute-angled angle
The distance x1 is represented by the following (Equation 3).

The light guide plate lighting device according to claim 1, wherein the light-shielding portion is provided on the incident surface side of the light emitting direction emitted from the emitting surface at a position serving as a starting point of the angle β. The light guide plate lighting device according to claim 2, wherein x1 ≈ 1.35 t. The light guide plate lighting device according to claim 2 or 3, wherein β≈16 °. The light guide plate lighting device according to any one of claims 1 to 4, wherein the plurality of light extraction structures are formed on the exit surface. The plurality of light extraction structures are prisms formed by concave portions or convex portions.
The induction according to any one of claims 1 to 5, wherein the acute angle τ formed by the extension line of an arbitrary surface constituting the plurality of light extraction structures and the emission surface is 15 ° or more and 55 ° or less. Light plate lighting device. The light guide plate lighting device according to any one of claims 1 to 6, wherein the thickness of the light guide plate becomes thinner as the distance from the incident surface increases. The light guide plate illumination according to any one of claims 1 to 7, wherein the light guide plate is in an inclined posture with respect to an irradiation surface irradiated with light emitted from the emission surface, and is supported by the housing. apparatus. The light guide plate lighting device according to any one of claims 1 to 8, further comprising a reflector provided on the back surface and reflecting light that guides the light guide plate. Further, it is housed in the housing and includes a power supply circuit for controlling the lighting of the light source.
The light guide plate lighting device according to any one of claims 1 to 9, wherein the power supply circuit is arranged vertically above the light source. The light guide plate lighting device according to claim 10, further comprising a substrate on which the light source is mounted and the power supply circuit is mounted. The housing further includes a first accommodating portion for accommodating the light guide plate and a second accommodating portion for accommodating the power supply circuit.
The light-shielding portion
Formed in the second accommodating portion
The light guide plate lighting device according to claim 10 or 11, wherein a part of the light-shielding portion extends so as to approach the light source and the incident surface.

Images