JP2014086405A - Lighting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide lighting equipment which improves the amount of emission light from light guide plate periphery and, thereby, can expect the superior efficiency of utilizing light.SOLUTION: A light reflection layer 9 is disposed on the surface of a peripheral part 81 with respect to a light guide plate 8 having a principal plane part 80 and the peripheral part 81 of a semi-parabolic cross-section of which the thickness decreases toward the marginal edge. A light emission element 61 of an LED mounting substrate 6 is arranged just under the peripheral part 81. Emission light of the light emission element 61 which transmits the peripheral part 81 is reflected on the light reflection layer 9 to the light guide plate 8 with a high reflectance upon the driving.

Description

  The present invention relates to an illumination device using an LED as a light source. The present invention particularly relates to a technique for improving light utilization efficiency.

In recent years, LED lighting devices using light emitting elements such as LED elements as a light source for illumination have become widespread.
FIG. 7 is an external configuration diagram showing a configuration example of a conventional desk stand type LED lighting device 1x. The LED lighting device 1x includes a pedestal portion 2x, an arm portion 3x erected on the pedestal portion 2x, and an illumination portion 4x attached to one end of the arm portion 3x. The illumination unit 4x incorporates an LED mounting board (not shown) formed by mounting LED elements of a plurality of light emitting elements on the surface.

  Moreover, the structure which arrange | positions a light-guide plate in the front surface of a LED mounting board is known as a backlight apparatus. There are a plurality of positions for arranging the light emitting elements with respect to the light guide plate. As an example, a configuration has been developed in which a light guide plate is disposed on an LED mounting substrate and light emitted from the LED element is emitted forward through the light guide plate (see, for example, Patent Documents 1 to 3).

JP 2004-31180 A JP 2004-31064 A JP 2004-319164 A

In the LED lighting device, it is required to improve the light use efficiency of the light emitting element. However, the conventional LED lighting device has a problem in terms of light utilization efficiency.
For example, as described above, when the light guide plate is disposed on the LED mounting substrate, the light use efficiency of light emission of the light emitting element guided from the periphery of the light guide plate is the light emitting element guided from other regions of the light guide plate. It may not be superior to the light utilization efficiency of light emission.

  An object of this invention is to provide the illuminating device which can anticipate the outstanding light utilization efficiency by improving the emitted light quantity radiate | emitted from the periphery of a light-guide plate.

  In order to solve the above-described problems, an illumination device according to one embodiment of the present invention includes a mounting substrate having a light-emitting element mounted on a surface thereof, and a light guide that is disposed on the mounting substrate and guides light emitted from the light-emitting element. The light guide plate includes an optical plate, and the light guide plate has a peripheral portion having a cross-sectional shape in which a thickness decreases toward an edge on a surface opposite to the surface facing the mounting substrate of the light guide plate. When the light guide plate and the mounting substrate are viewed in plan, the light emitting element is disposed at a position overlapping the peripheral edge, and the peripheral edge is transmitted to at least a part of the area facing the surface of the peripheral edge. The light-emitting element is configured to have a light reflecting portion that reflects light emitted from the light-emitting element toward the light guide plate.

Here, in another aspect of the present invention, the mounting substrate and the light guide plate are both disk-shaped, the peripheral edge is present over the entire circumference of the light guide plate and has a semiparabolic cross-sectional shape, A plurality of the light emitting elements may be mounted at a predetermined interval.
As another aspect of the present invention, the light reflecting portion may be a light reflecting layer deposited on the surface of the peripheral edge.

As another aspect of the present invention, the light reflecting layer may be a vapor deposition film containing titania.
As another aspect of the present invention, a configuration may be adopted in which a cover that covers the light reflection layer is provided above the light reflection layer.
Moreover, as another aspect of the present invention, a cover that covers the surface of the peripheral portion may be provided, and the light reflecting portion may be disposed on the surface of the cover that faces the surface of the peripheral portion. it can.

As another aspect of the present invention, the light reflecting portion may be a light reflecting film formed on the surface of the cover.
As another aspect of the present invention, the light reflecting film may be a coating film containing a white pigment.
As another aspect of the present invention, the cover and the peripheral edge of the light guide plate may be in close contact with each other or close to each other at a distance of 0.5 mm or less.

As another aspect of the present invention, the light guide plate may include a diffusion plate that is laminated on the opposite surface and diffuses light emitted from the light emitting element.
As another aspect of the present invention, when the light guide plate and the mounting substrate are viewed in plan view,
The periphery of the light guide plate may be positioned immediately above the light emitting element.

  Also, as another aspect of the present invention, a covering member that houses the mounting substrate and the light guide plate in a state in which light emitted from the light guide plate can be extracted outside, a pedestal portion, It can also be set as the structure which has an arm part which supports a coating | coated member.

  In the lighting device according to one embodiment of the present invention having the above structure, a light guide plate having a peripheral edge portion having a cross-sectional shape whose thickness decreases toward the edge is used. A light reflecting portion is provided in at least a part of the region facing the peripheral surface. When the lighting device is driven, light emitted from the light-emitting element that has passed through the peripheral portion is reflected by the light reflecting portion toward the light guide plate with high efficiency. Thereby, the light emission of the light emitting element incident on the peripheral portion can be emitted to the outside through the light guide plate and contribute to the illumination light. Therefore, it is possible to provide an illumination device that can improve the amount of light emitted from the periphery of the light guide plate and can expect excellent light utilization efficiency.

1 is an external configuration diagram of an LED lighting device 1 according to Embodiment 1. FIG. FIG. 4 is a development view showing an internal configuration of the illumination unit 4. FIG. 4 is a development view showing an internal configuration of the illumination unit 45. It is sectional drawing (AA sectional view taken on the line of FIG. 1) which shows the internal structure of the illumination part 4. FIG. It is an expanded sectional view of the periphery part 81 periphery. It is an expanded sectional view of the periphery part 81 of light guide plate 8A in the illumination part of the LED illumination device according to Embodiment 2. It is an external appearance block diagram of the conventional LED lighting apparatus 1x.

Hereinafter, each embodiment of the present invention will be described.
<Embodiment 1>
The LED lighting device 1 according to the first embodiment (hereinafter referred to as “device 1”) will be described with reference to FIGS. FIG. 1 is an external configuration diagram of the apparatus 1. FIG. 2 is a development view of the illumination unit 4. FIG. 3 is a development view showing the internal configuration of the illumination unit 45. FIG. 4 is a cross-sectional view (a cross-sectional view taken along the line AA in FIG. 1) illustrating the internal configuration of the illumination unit 4. FIG. 5 is an enlarged cross-sectional view of the periphery of the light guide plate peripheral portion 81 of the illumination unit 4.

As shown in FIG. 1, the device 1 includes a pedestal part 2, an arm part 3, and an illumination part 4.
Next, each component of the apparatus 1 will be described.
[Pedestal part 2]
The pedestal 2 is used as means for stably placing the device 1 on a desk or the like. Here, the pedestal portion 2 is configured as an annular appearance. The exterior of the pedestal portion 2 is made of a resin injection molded product. A necessary and sufficient amount of weight is incorporated in the pedestal portion 2 in order to ensure stability when the device 1 is placed.
[Arm part 3]
The arm part 3 is used as means for supporting the covering members (the first covering member 40 and the second covering member 41) of the illumination part 4 (FIGS. 1 and 2). It is also used as a means for adjusting the position of the illumination unit 4. The arm part 3 is erected on the base part 2. The arm part 3 includes a first arm member 3a and a second arm member 3b from the base part 2 side. Moreover, the arm part 3 is provided with the connection parts 3d, 3e, and 3f. The arm portion 3 is formed of a resin injection-molded product, like the pedestal portion 2, in the exterior of the pedestal portion 2.

  The 1st arm member 3a is connected with the base part 2 in the state supported by the connection part 3d provided in the lower one end side. Further, the first arm member 3a is coupled to the second arm member 3b while being pivotally supported by a coupling portion 3e provided at the other end. Each of the connecting portions 3d and 3e has a hinge structure that opens and closes with a constant torque. Therefore, for example, when the user pulls the second arm member 3b closer, the angle between the first arm member 3a and the second arm member 3b opens accordingly. Furthermore, the angle between the base 2 and the first arm member 3a is opened. Thereby, the arm part 3 is extended to the user side.

An operation portion 3c is disposed on the front side of the first arm member 3a. The operation unit 3c operates, for example, by a capacitive method. Each time the user touches the operation unit 3c, the illumination unit 4 can be turned on / off. In addition, the user can perform light control of the illumination unit 4 by sliding a finger on the operation unit 3c.
Although not shown, a cable (not shown) is connected to the operation unit 3c from the outside. Power is supplied from the commercial power source to the operation unit 3c and the illumination unit 4 via this cable.

The connecting portion 3f is provided on the lower surface side of the second arm member 3b (FIG. 4). The connecting portion 3f has a ball joint structure. The connecting part 3f is used as means for hanging the illumination part 4 from the second arm member 3b (FIG. 4). By adopting the connecting part 3f having a ball joint (ball joint) structure, when the user operates the illumination part 4, the angle of the illumination part 4 can be adjusted in all directions intersecting the horizontal (XY plane) direction.
[Lighting unit 4]
The illumination unit 4 functions as a light emitting unit in the device 1. As shown in FIG. 2, the illuminating unit 4 includes a pair of covering members (a first covering member 40 and a second covering member 41), and an illumination unit 45 disposed between them, as shown in FIG. In the apparatus 1, the illumination unit 4 is configured in a disk shape as an example.

The first covering member 40 and the second covering member 41 are each configured as an injection molded product using a resin material such as ABS (acrylonitrile butadiene styrene copolymer) resin.
On the inner surface of the first covering member 40, a fixing plate 43 for holding the connecting portion 3f with a predetermined rotational torque and a plurality of ribs 44 for aligning the illumination unit 45 are provided.
The second covering member 41 is formed in an umbrella shape as a whole. In the center of the second covering member 41, an opening 42 that matches the diameter of the diffusion plate 10 of the illumination unit 45 is provided.

The illumination unit 45 has a heat sink 5 and an annular front cover 11 that are stacked on each other in appearance. The diffusion plate 10 is exposed from the opening 112 of the front cover 11. The diffusion plate 10 is exposed to the outside through the opening 42 of the second covering member 41.
As shown in FIG. 3, the illumination unit 45 includes a heat sink 5, an LED mounting substrate 6, a diffuse reflection sheet 7, a light guide plate 8, a light reflection layer 9, a diffuser plate 10, and a front surface. And a cover 11. The illumination unit 45 is configured by stacking these components in the same order and screwing a plurality of male screws B1 to B8 into the female screws 52A to 52H of the heat sink 5 from above the front cover 11, respectively.
(I) Heat sink 5
The heat radiating plate 5 is disposed as a means for radiating driving heat of the light emitting element 61. The heat sink 5 is configured using a metal material having excellent heat capacity such as iron or aluminum. As an external configuration of the heat sink 5, the heat sink 5 includes a convex portion 51 disposed in the center of one surface and a flat portion 50 disposed around the convex portion 51. The convex portion 51 is used for inserting the LED mounting substrate 6 and placing the diffuse reflection sheet 7 thereon. The flat part 50 is used for mounting the LED mounting substrate 6. Incidentally, female screws 52A to 52H are formed around the flat portion 50 (FIG. 3).
(Ii) LED mounting board 6
The LED mounting substrate 6 includes an annular substrate body 60, a light emitting element 61, a wiring 63, and a connector 62 for electrically connecting each light emitting element 61 and the wiring 63 (FIG. 3).

As an example, the substrate body 60 is configured mainly using a glass composite material. The substrate body 60 has a wiring pattern for electrically connecting the light emitting element 61 on at least the upper surface. The lower surface of the substrate body 60 is disposed so as to be thermally coupled to the surface of the flat portion 50 of the heat sink 5 (FIGS. 3 and 4).
The substrate body 60 can also be configured using a known flexible substrate.

  The light emitting element 61 is a light source for illumination in the apparatus 1. The light emitting element 61 is specifically an LED element (LED package). That is, the LED element as the light emitting element 61 is formed by, for example, covering an LED chip mounted on a substrate with a sealing resin. A plurality of light emitting elements 61 (18 in this case) are mounted on the upper surface of the substrate body 60 at regular intervals. When the LED mounting substrate 6 is viewed in plan along the Z direction, each mounting position of the light emitting element 61 is adjusted to a position overlapping the peripheral edge 81 of the light guide plate 8 (FIG. 4). Although not shown in FIG. 3, other electric elements such as a resistance element are also mounted on the surface of the substrate body 60.

The connector 62 is formed of an injection molded product using a resin material such as PP (polypropylene) or PE (polyethylene). The connector 62 incorporates a conductive member (not shown) inside. The connector 62 is a conductive member and is used to electrically connect the wiring 63 and the wiring pattern of the board body 60.
The wiring 63 is configured by covering an axial lead wire with an insulating member. The wiring 63 is electrically connected to the wiring pattern of the substrate body 60. Furthermore, the wiring 63 is electrically connected to the operation portion 3c in a state where the wiring 63 is inserted into each of the connecting portion 3f and the first arm member 3a.

The connector 62 is not essential. The wiring 63 can also be electrically connected directly to the wiring pattern.
(Iii) Diffuse reflection sheet 7
The diffuse reflection sheet 7 is used as a means for reflecting light emitted from the light emitting element 61 irregularly reflected on the back surface of the light guide plate 8 to the outside through the opening 112 of the front cover 11. The diffuse reflection sheet 7 is configured by mixing a white pigment with a resin material such as PET (polyethylene terephthalate) and forming it into a sheet shape. As an external structure, it has the flat-plate-shaped main-body part 70, the hole 71 formed according to the position of the light emitting element 61, and the notch part 72 formed according to the position of the connector 62 (FIG. 3). The light emitting element 61 is inserted through the hole 71 of the diffuse reflection sheet 7.

In order to prevent the light use efficiency of the light emitting element 61 from being lowered, care should be taken that the thickness of the diffuse reflection sheet 7 is not higher than the height of the light emitting element 61 on the substrate body 60 (the height in the Z direction).
In addition, a hole other than the hole 71 can be provided in the diffuse reflection sheet 7 so that an electric element other than the light emitting element 61 mounted on the LED mounting substrate 6 can be inserted therethrough.
(Iv) Light guide plate 8
The light guide plate 8 is used as a means for diffusing the light emitted from the light emitting element 61 during driving and emitting the light efficiently to the outside. The light guide plate 8 is configured by dispersing a diffusing material in a resin material having a constant refractive index, for example, an acrylic resin such as PC (polycarbonate) or PMMA (polymethyl methacrylate) resin. As an external appearance configuration, it has a flat main surface portion 80, a peripheral edge portion 81 surrounding the main surface portion 80, and a light reflecting layer 9 provided on the surface of the peripheral edge portion 81 (FIGS. 3 and 4). The light guide plate 8 is disposed along the surface of the LED mounting substrate 6 via the diffuse reflection sheet 7.

  When viewed macroscopically, the lower surface of the main surface portion 80 (the surface facing the diffuse reflection sheet 7) is formed uniformly and flat. On the other hand, when the lower surface of the main surface portion 80 is viewed microscopically, fine unevenness processing is performed based on, for example, a printing method. Thereby, an uneven surface is formed on the lower surface of the main surface portion 80. The uneven surface of the main surface portion 80 diffuses diffused light emitted from the light emitting element 61 widely. And it is used as a means to reflect this diffused diffused light to the diffuse reflection sheet 7 side.

  The peripheral edge 81 exists over the entire circumference of the light guide plate 8. On the upper surface side of the light guide plate 8, the peripheral edge 81 has a parabolic cross-sectional shape whose thickness decreases toward the edge (FIGS. 3 and 4). Thereby, the peripheral part 81 has a lens structure. When the light guide plate 8 is viewed in plan, the light emitting element 61 is disposed at a position overlapping the peripheral edge 81. By disposing the peripheral portion 81 above the light emitting element 61, the mounting position of the light emitting element 61 becomes difficult to visually recognize due to the lens effect of the peripheral portion 81 when the light guide plate 8 is viewed in plan. As a result, when the device 1 is driven, it is possible to suppress luminance unevenness in which high-luminance light emission occurs at the mounting position of the light emitting element 61.

The “semi-parabolic shape” mentioned here does not refer to only a mathematically exact shape. The “semi-parabolic shape” mentioned here includes a curved surface shape whose thickness decreases toward the edge.
In addition, when the thickness of the light guide plate 8 is increased, the curvature of the peripheral portion 81 can be reduced. However, it should be noted that sinks may occur when the light guide plate 8 is formed by injection molding using a resin material.
(V) Light reflecting layer 9
The light reflecting layer 9 is one of the characteristic parts of the device 1. The light reflecting layer 9 is provided on the surface of the peripheral edge portion 81. Specifically, the light reflection layer 9 is a vapor deposition film containing titania (TiO ₂ ) deposited on the surface of the peripheral portion 81. The light reflection layer 9 is a white layer in appearance. The light reflecting layer 9 is used as a light reflecting portion for efficiently reflecting incident light of the light emitting element 61 transmitted through the peripheral edge portion 81 toward the main surface portion 80 side and using it for outgoing light to the outside.
(Vi) Diffuser 10
The diffusing plate 10 is disposed in order to further uniformly diffuse the light emitted from the light emitting element 61 that is incident from the light guide plate 8 side to obtain surface light emission. The diffusion plate 10 is made of a resin material such as PC. The diffusion plate 10 is colored, for example, blue for the purpose of adjusting the emission color of the light emitting element 61. Thereby, the yellow component is removed from the light emitting component of the light emitting element 61.
(Vii) Front cover 11
The front cover 11 is used as a means for holding the LED mounting substrate 6, the diffuse reflection sheet 7, the light guide plate 8, and the diffusion plate 10 in the same order stacked with the heat sink 5. The front cover 11 covers the peripheral edge 81 of the light guide plate 8. Thereby, the light emitting element 61 directly under the peripheral part 81 is adjusted so that it cannot be visually recognized from the outside (FIG. 4). The front cover 11 has an annular flat plate portion 110 and an opening 112 existing inside thereof as an external configuration. Screw holes 111A to 111H through which male screws B1 to B8 are inserted are provided on the surface of the flat plate portion 110 (FIG. 3).
(About the effect of the device 1)
The device 1 having the above configuration includes the light reflecting layer 9 as a light reflecting portion at a position facing the surface of the peripheral edge portion 81 of the light guide plate 8. As a result, as shown in FIG. 5, when the device 1 is driven, incident light incident on the peripheral portion 81 at any incident angle from the light emitting element 61 is reflected with high efficiency on the light guide plate 8 side in the light reflecting layer 9. be able to.

Specifically, the incident light of the light emitting element 61 that is incident on the peripheral edge 81 is emitted to the outside from the light guide plate 8 and becomes emitted light L _{1 to} L ₃ . These outgoing lights L _{1 to} L ₃ are derived from the outgoing light reflected with high efficiency in the light reflection layer 9. Accordingly, the emitted lights L _{1 to} L ₃ have a sufficient amount of light. Therefore, the outgoing lights L _{1 to} L ₃ can contribute well to the illumination light together with the other outgoing lights L ₄ and L _{5 of the} light emitting element 61. As a result, the device 1 can be expected to exhibit excellent light utilization efficiency.

Hereinafter, another embodiment of the present invention will be described focusing on differences from the first embodiment.
<Embodiment 2>
FIG. 6 is an enlarged cross-sectional view around the periphery of the light guide plate in the illumination unit of the LED illumination apparatus according to Embodiment 2. As a different point from the first embodiment, the light reflecting layer 9 is not provided at a position facing the surface of the peripheral edge 81 of the light guide plate 8A. On the other hand, the light reflection film 114 is provided on the inner surface 113 of the front cover 11 </ b> A at a position facing the peripheral edge 81. For example, the light reflecting film 114 is a white coating film containing a white pigment and a resin binder.

In the second embodiment, the light reflecting film 114 functions as a light reflecting portion for light emission of the light emitting element 61.
Also in the second embodiment having the above configuration, the same effect as in the first embodiment can be expected. That is, as shown in FIG. 6, the light emitted from the light emitting element 61 that has passed through the peripheral portion 81 is reflected with high efficiency by the light reflecting film 114 and is incident on the main surface portion 80 side of the light guide plate 8A. Incident light becomes outgoing light L ₁ ~L ₃ is emitted to the outside from the light guide plate 8A. The outgoing lights L _{1 to} L ₃ can contribute well as illumination light together with the other outgoing lights L ₄ and L ₅ .

In the second embodiment, the light reflecting film 114 can be disposed using a coating method. Therefore, the manufacturing process for providing the light reflecting film 114 is easy, and high feasibility can be expected.
<Other matters>
In each of the above embodiments, the disk-shaped illumination unit 4 is shown. However, the illumination unit 4 is not limited to a disk shape, and may be, for example, a rectangular shape (rectangular shape), a polygonal shape, or an elliptical shape. In this case, the shape of the light guide plate 8 is not limited to a disk shape, and may be a rectangular shape or a polygonal shape according to the shape of the illumination unit 4. Further, the shape of the base portion 2 is not limited, and may be any one of an irregular shape such as a cylindrical shape, a polygonal cylindrical shape, a columnar shape, a polygonal columnar shape, a conical shape, a polygonal pyramid shape, a dome shape, or a heart side Good.

When the light reflecting layer 9 is disposed on the peripheral edge 81 of the light guide plate 8, the light reflecting layer 9 is not limited to the vapor deposition film. In addition, it can also arrange | position as a coating film containing a white pigment.
Moreover, in the LED irradiation apparatus of this invention, the light reflection layer 9 and the light reflection film 114 can also be arrange | positioned simultaneously.
When the light reflecting layer 9 is configured as a vapor deposition film, a material other than titania may be used as the reflecting material. For example, metal compounds such as silicon dioxide, zirconium oxide, magnesium fluoride, and magnesium oxide, or metal materials such as nickel, chromium, and aluminum can be used.

The light reflection layer 9 is not limited to being configured as a vapor deposition film. The light reflecting layer 9 may be composed of, for example, a sputtering film, a plating film, or a coating film. In the case of a coating film, it can be set as the structure containing microparticles | fine-particles, such as a titania particle, a silicon dioxide, a zirconium oxide, a magnesium fluoride, a ceramic, and aluminum.
The light reflecting film 114 is not limited to a structure containing a white pigment. For example, it is good also as a structure containing the metal particle of high light reflectivity. Moreover, you may comprise with a highly light reflective metal plating film. Alternatively, the light reflecting film 114 may be composed of a light reflecting member such as a hard metal member.

The light reflecting film 114 can also be formed over the entire back surface of the front cover 11A.
The light reflecting layer 9 or the light reflecting film 114 is not limited to the structure provided over the entire region of the peripheral edge 81 surrounding the edge of the light guide plates 8 and 8A. For example, it can also be provided in at least a partial region facing the surface of the peripheral edge 81 located immediately above the mounting position of each light emitting element 61.
The arm part 3 is not limited to the structure using the connection parts 3d, 3e, and 3f shown in FIG. For example, the arm portion 3 may be configured by a single columnar or shaft-like member like the arm portion 3X of FIG.

  In the second embodiment, it is most desirable that the peripheral portion 81 and the light reflecting film 114 are in close contact with each other. In the actual manufacturing process, there may be a tolerance gap between the light reflecting layer 9 and the front cover 11. If the tolerance gap is considerably large, the light transmitted through the peripheral portion 81 may be attenuated or scattered and lost. This makes it difficult to effectively use the incident light on the peripheral portion 81 as illumination light. Therefore, in the illuminating device of the present invention, it is desirable that the peripheral edge 81 of the light guide plate 8 and the front cover 11 are close to each other within a distance of within 0.5 mm (particularly within 0.3 mm).

If the light guide plate 8 is in close contact with the front cover 11 (11A) at the peripheral portion 81, the light emitted from the light emitting element 61 can be efficiently guided without using the light reflecting layer or the light reflecting film 114. . In this case, in the lighting device, the front surface of the peripheral portion 81 and the back surface (113) of the front cover 11 function as a light reflecting portion.
In each of the above embodiments, a desk stand type LED lighting apparatus has been shown. However, the LED lighting device of each aspect of the present invention is not limited to the desk stand type. For example, a LED lighting device such as a ceiling type or a downlight type may be used.

  The light emitting element used in the present invention is not limited to the LED element. As the light emitting element of the present invention, other light emitting elements can be used. For example, a fluorescent lamp, an incandescent lamp, an organic EL (Electro-Luminescence) element, an LD (Laser Diode) or the like may be used alone or in combination.

L _{1 to} L ₅ emitted light _1, 1x LED illumination device 2, 2x pedestal part 3, 3x arm part 4, 4x illumination part 5 heat sink 6 LED mounting substrate 7 diffuse reflection sheet 8, 8A light guide plate 9 light reflection layer 10 diffusion Plate 11, 11A Front cover 40 First covering member 41 Second covering member 42 Opening 45 Lighting unit 50 Flat part 51 Convex part 60 Substrate body 61 Light emitting element (LED element)
62 Connector 71 Hole 80 Main surface portion 81 Peripheral portion 113 Inner surface 114 Light reflecting film

Claims (12)

A lighting device comprising: a mounting substrate having a light emitting element mounted on a surface; and a light guide plate that is disposed on the mounting substrate and guides light emitted from the light emitting element,
The light guide plate has a peripheral portion of a cross-sectional shape in which the thickness decreases toward the edge on the surface opposite to the surface facing the mounting substrate of the light guide plate,
When the light guide plate and the mounting substrate are viewed in plan, the light emitting element is disposed at a position overlapping the peripheral portion,
An illumination apparatus, comprising: a light reflecting portion that reflects light emitted from the light emitting element that has passed through the peripheral edge toward the light guide plate, in a part or more of the region facing the surface of the peripheral edge. Both the mounting substrate and the light guide plate are disk-shaped,
The peripheral portion exists over the entire circumference of the light guide plate and has a semi-parabolic cross-sectional shape,
The lighting device according to claim 1, wherein a plurality of the light emitting elements are mounted at regular intervals. The lighting device according to claim 1, wherein the light reflecting portion is a light reflecting layer that is attached to a surface of the peripheral edge portion. The lighting device according to claim 3, wherein the light reflection layer is a vapor deposition film containing titania. The lighting device according to claim 3, further comprising a cover that covers the light reflection layer above the light reflection layer. A cover that covers the surface of the peripheral edge;
The lighting device according to claim 1, wherein the light reflecting portion is disposed on a surface of the cover facing a surface of the peripheral edge portion. The lighting device according to claim 6, wherein the light reflecting portion is a light reflecting film formed on a surface of the cover. The lighting device according to claim 7, wherein the light reflecting film is a coating film containing a white pigment. The lighting device according to any one of claims 6 to 8, wherein the cover and the peripheral edge portion of the light guide plate are in close contact with each other or close to each other at a distance of 0.5 mm or less. The lighting device according to claim 1, further comprising a diffusion plate that is laminated on the opposite surface of the light guide plate and diffuses light emitted from the light emitting element. When viewing the light guide plate and the mounting substrate in plan view,
The lighting device according to claim 1, wherein the peripheral edge portion of the light guide plate is located immediately above the light emitting element. A covering member that accommodates the mounting substrate and the light guide plate in a state in which the light emitted from the light guide plate can be extracted outside;
A pedestal,
The lighting device according to any one of claims 1 to 11, further comprising an arm portion that stands on the pedestal portion and supports the covering member.

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