JP2014116235A - Illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device including a light guide plate in which a light incident part has an inclined part in which, even when chip dislocation occurs in a mounting position of a light emitting element, occurrence of luminance unevenness can be suppressed and uniform surface emission can be expected.SOLUTION: An illumination device 100 is configured in which an LED mounting substrate, a reflection member and a light guide plate are arranged in this order upward. In the reflection member 30, an opening 34 for communicating with a light emitting element in a thickness direction is provided. The light guide plate 40 has a light-incident part 42 in a position of a surface corresponding to the opening 34. The light-incident part 42 includes: an element facing part 420 facing the light emitting element 22; and inclined parts 422A and 422B having inclined surfaces in which an inclination angle with respect to a vertical (Z) direction increases as going further away from the element facing part 420, on a surface opposite to the surface where the element facing part 420 of the light guide plate 40 exists. In a Y direction, the width of the element facing part 420 is set to be larger than the width of the opening 34, and both end parts on the peripheral edge of the opening 34 are positioned further inner side than both end parts of the element facing part 420.

Description

  The present invention relates to an illumination device including a light emitting element such as an LED (Light Emitting Diode) as a light source. The present invention particularly relates to a technique for reducing luminance unevenness in a lighting device that emits light using a light guide plate.

  For example, an illumination device 900 shown in a cross-sectional view of FIG. 16 has been developed as a surface-emitting illumination device using a light guide plate. The lighting device 900 includes a plurality of light emitting elements 922, a reflecting member 945, and a light guide plate 940. Both the reflection member 945 and the light guide plate 940 have a disk shape whose plane direction is a direction perpendicular to the paper surface. The light guide plate 940 has a light incident portion 941 that surrounds each light emitting element 922 from above. The light emitting elements 922 are arranged circumferentially at intervals with the main emission direction directed toward the light guide plate 940. The apparatus 900 includes a power supply unit (not shown) for supplying power to each light emitting element 922. At the time of driving, light emitted from the light emitting element 922 enters the incident surface 944b of the light incident portion 941. Incident light is reflected by the reflecting surface 941 a located on the front side of the light incident portion 941, and includes an inner light guide portion 942 located inside the light incident portion 941, and an outer light guide portion 943 located outside the light incident portion 941. Is guided to. Thereafter, the incident light is emitted to the outside as uniform illumination light from the light emitting surfaces 942a and 943a which are front surfaces of the inner light guide portion 942 and the outer light guide portion 943.

JP 2012-104476 A

In the surface light emission type illumination device, for example, the use of the light guide plate 940X including the light incident portion 946X illustrated in the partial cross-sectional view of the illumination device 910 (FIG. 17A) can be assumed. The light incident portion 946X includes an element facing portion 947X, inclined portions 948X and 949X, and side surface portions 950X and 951X existing on the opposite side of the inclined portions 948X and 949X. The element facing portion 947 </ b> X is disposed to face the emission surface of the light emitting element 922 in the gap between the reflecting members 30 </ b> X existing around the light emitting element 922. The inclined portions 948X and 949X are inclined surfaces arranged such that the inclination angle with respect to the vertical (Z) direction increases on the surface of the light guide plate 940X opposite to the element facing portion 947X, as the distance from the element facing portion 947X increases. Have At the time of driving, emitted light including L _{9 to} L _{12 and the} like is incident on the element facing portion 947X from the light emitting element 922. Thereafter, the emitted light is efficiently regularly reflected in the vicinity of the inclined portions 948X and 949X and guided to the entire light guide plate 940X. The reflection member reflected light is once reflected by 945X side surface portion 950X as light L ₁₃ in FIG. 17 (a), incident 951x.

In order to obtain the above effect with the lighting device 910, strictness is required for the positional relationship between the light emitting element 22 and the light guide plate 940X. However, a misalignment error (hereinafter referred to as “chip misalignment”) in which the mounting position of the light emitting element 922 deviates from the target position may occur.
When the chip is displaced, the relative position between the light emitting element 922 and the light incident portion 946X is also shifted as shown in the partial cross-sectional view in FIG. Accordingly, in the direction in which the chip is displaced (here, the right side), the light is directly incident from the side surface portions 950X and 951X (here, 951X) without being reflected by the reflecting member 945X without passing through the element facing portion 947X. In addition, the light incident on the inclined portion 949X at a relatively large incident angle increases. The incident light is emitted to the outside penetrating the inclined portion 949X, can be a direct light L ₁₄ of high luminance. When the illumination device 910 is viewed from the outside, the luminance in the region where the chip shift has occurred is higher than the luminance in other regions. Therefore the light emitting surface of the illumination apparatus 910, and the output region of the direct light L _14, may occur directly non emitting area of the light L ₁₄ is. The generation | occurrence | production of the subject that a brightness nonuniformity arises for this causes is assumed. There are also lights L ₁₃ and L ₁₅ that are once reflected and diffused by the reflecting member 945X and emitted to the outside (FIGS. 17A and 17B), but these lights are diffused and intensified. Is difficult to cause the above problem.

  The present invention has been made in view of the above problems, and in a lighting device including a light guide plate having a light incident portion having an inclined portion, even when the mounting position of the light emitting element is displaced from the chip, luminance unevenness occurs. An object of the present invention is to provide an illuminating device that can suppress uniform light emission and can expect uniform surface light emission.

  In order to achieve the above object, an illumination device according to an aspect of the present invention includes a mounting substrate on which a plurality of light emitting elements are mounted, a light guide plate that guides light emitted from each of the light emitting elements, and the mounting substrate. A lighting device including a plate-like member sandwiched between the light guide plate and having an opening penetrating in a thickness direction at a position corresponding to each light emitting element, wherein the light guide plate corresponds to the opening. A light incident portion where the light emitted from the light emitting element is incident through the opening, the light incident portion including an element facing portion facing the light emitting element, and the element facing portion of the light guide plate. An inclined surface having an inclined surface whose angle of inclination with respect to a direction perpendicular to the surface of the mounting substrate increases as the distance from the element facing portion increases in a first direction along the surface of the mounting substrate on a surface opposite to the existing surface. The light guide plate in plan view Along the first direction, the width of the opening is configured to both end portions of the peripheral edge of small and the opening than the width of the element facing portion are positioned inside the both end portions of the element facing portion.

Here, in another aspect of the present invention, the plate-like member has a recessed portion having a recessed surface, the opening is present inside the recessed portion, and the light incident portion is in the recessed portion. It can also be set as the structure inserted.
In another aspect of the present invention, the light incident portion has the inclined portion at each position corresponding to the both end portions of the element facing portion along the first direction, and the inclined portion It is also possible to adopt a configuration in which the inclination of the surface gradually decreases as the distance from the element facing portion increases.

In another aspect of the present invention, the opening has a first opening existing at a position corresponding to the light emitting element, a diameter communicating with the first opening, and larger than a maximum diameter of the first opening. It is also possible to adopt a configuration in which the light incident portion is disposed close to a position corresponding to the first opening.
In another aspect of the present invention, the plate member may be a reflecting member that reflects the emitted light of the light emitting element.

In another aspect of the present invention, the reflecting member has side walls on both sides of the first opening in the recessed portion along the first direction, and each side wall has the first opening. It can also be set as the structure arrange | positioned on the straight line which ties any one of the both ends of the said periphery of a part, and either one of the said both ends of the said periphery of the said light-incidence part which adjoins this.
In another aspect of the present invention, the pair of side walls may be present outside the both ends of the peripheral edge of the first opening along the one direction.

In another aspect of the present invention, a pair of the second openings may be in communication with each other on both sides of the first opening in a second direction orthogonal to the first direction. it can.
According to another aspect of the present invention, the plurality of light emitting elements are mounted with a space therebetween, and the second opening is located at a position corresponding to a position between adjacent mounting positions of the light emitting elements. You can also.

In another aspect of the present invention, the plurality of light emitting elements are mounted on the surface of the mounting board in a circumferential shape, and the light incident portion of the light guide plate is mounted on each mounting element on the mounting board. It can also be set as the structure currently formed so that may be tied.
Moreover, in another aspect of the present invention, the light guide plate has a disk shape, and includes a first light guide portion located inside the light entrance portion and a second light guide portion located outside the light entrance portion. And the first direction may be a direction passing through the diameter of the light guide plate.

In another aspect of the present invention, the outer surfaces of the first light guide and the second light guide are the same height, and the first light guide and the second light guide have the same thickness. It can also be set as the structure which is.
In another aspect of the present invention, the plate member and the light guide plate may be formed by injection molding.
In another aspect of the present invention, the light emitting element may be an LED element.

  In another embodiment of the present invention, a power supply device for supplying power to the light emitting element may be provided.

In the lighting device according to one embodiment of the present invention, when the light emitted from the light emitting element passes through the opening of the plate-like member during driving, the lighting apparatus has a width narrower than the width of the element facing portion of the light incident portion along the first direction. The emitted light is partially shielded at both ends of the periphery of the opening.
As a result, even if the light emitting element has a chip shift in the first direction with respect to the light incident part, the light emitted from the light emitting element having a high intensity incident on the light guide plate has an inclined part with a large inclination angle with respect to the vertical direction. It can be prevented from penetrating and being emitted to the outside as direct light with high luminance.

  As a result, in an illuminating device including a light guide plate having a light incident portion having an inclined portion, even when the mounting position of the light emitting element is displaced from the chip, it is possible to expect uniform surface light emission while suppressing occurrence of luminance unevenness. A possible lighting device can be provided.

It is a partial cross section figure which shows the structure and installation example of the illuminating device 100 which concern on Embodiment 1. FIG. It is a figure which shows the external appearance structure and internal structure of the lighting fixture 1. FIG. It is an exploded view (combination drawing) which shows the internal structure of the lighting fixture 1. FIG. 2 is a partial cross-sectional perspective view showing the internal configuration of the lighting fixture 1. FIG. 4 is a partial cross-sectional perspective view showing a configuration of a reflecting member 30. FIG. FIG. 3 is a diagram showing a configuration of a reflecting member 30. (A) is the front view seen from the diffusion cover 50 side (upper surface side), (b) is the front view seen from the base 10 side (lower surface side). FIG. 4 is a partial cross-sectional view showing a configuration around a light incident portion 42. FIG. 6 is a partial cross-sectional view around a light incident part 42 showing light emitted from the light emitting element 22 in which chip displacement has occurred. FIG. 4A is a partial cross-sectional view around a light incident part 42 showing light emitted from a normal light emitting element 22 (no chip displacement). (B) is a partial sectional view showing the emission angle theta ₁ of the emitted light L _1, L _2, an exit angle theta ₂ of the outgoing light L _2, L _4. This is data showing a luminance unevenness pattern and an illuminance distribution when a chip shift occurs in the comparative example. This is data showing a luminance unevenness pattern and an illuminance distribution when a chip shift occurs in the embodiment. It is the photograph (b) which shows the brightness | luminance pattern (a) which produced the brightness nonuniformity in the comparative example, and the mode of actual light emission. It is the photograph (b) which shows the typical brightness | luminance pattern (a) in an Example, and the mode of actual light emission. It is a figure which shows the structure of each opening which concerns on Embodiment 2-5 of this invention. It is a fragmentary sectional view around 42 A of light incident parts which shows the structure of 42 A of light incident parts which concern on Embodiment 6 of this invention. It is sectional drawing which shows the structure of the conventional illuminating device 900. FIG. They are a partial sectional view (a) around the light incident portion 946X in the lighting device 910 and a partial sectional view (b) around the light incident portion 946X showing the problem of the lighting device 910.

Hereinafter, lighting devices according to aspects of the present invention will be described with reference to the drawings.
<Embodiment 1>
(Configuration of LED lighting device 100)
As shown in the partial cross-sectional view (FIG. 1) showing the configuration and installation example of the LED lighting device 100, the LED lighting device 100 (hereinafter simply referred to as “device 100”) includes the LED lighting device 1 and a leaf spring shape. , And a power supply unit 4 for lighting the lighting fixture 1. The luminaire 1 is electrically connected to the power supply unit 4 by wiring 23. The latch member 3 is attached to the base 10 on the back side of the lighting fixture 1. In the first embodiment, the device 100 is a downlight embedded in the ceiling.

When the apparatus 100 is installed, the power supply unit 4 is placed on the back surface 2 b of the ceiling 2 through the through hole 2 a provided in the ceiling 2. The lighting fixture 1 is arrange | positioned with respect to the through-hole 2a so that the base 10 may be accommodated. At this time, the latch member 3 is latched around the periphery of the through hole 2a. Thereby, the apparatus 100 can be installed on the ceiling 2.
As shown in a diagram (FIG. 2) showing an external configuration and an internal configuration of the LED lighting device 1, the external configuration of the LED lighting device 1 is roughly composed of a base 10 and a diffusion cover 50. A wiring 23 is extended from the notch 16 of the base 10 to the outside.

Note that the dotted lines in FIG. 2 indicate the positions of the built-in LED mounting substrate 20, the light emitting element 22, and the substrate body 21.
(Configuration of LED lighting apparatus 1)
As shown in an exploded view (FIG. 3) showing the internal configuration of the lighting fixture 1, the LED lighting fixture 1 (hereinafter simply referred to as “the fixture 1”) includes a base 10, an LED mounting substrate 20, and a reflecting member 30. And a light guide plate 40 and a diffusion cover 50. The instrument 1 has a disk-like overall shape. Each outer peripheral shape of the base 10, the LED mounting substrate 20, the reflecting member 30, the light guide plate 40, and the diffusion cover 50 is formed in a circle according to the overall shape of the lighting fixture 1.
[Base 10]
The base 10 is made of a material having excellent heat dissipation characteristics, for example, a metal material such as an aluminum die-cast material. The base 10 has a main body part 11 having a two-step bottom structure with a deep center side and a shallow peripheral edge side, and a flange part 12 erected around the main body part 11 (FIG. 3). The flange portion 12 has a notch portion 16.

The main body 11 has a disk-shaped inner bottom 13 with a deep bottom, an inner bottom 13 with a shallow bottom, a side wall 14 erected on the periphery of the inner bottom 13, And an annular outer bottom portion 15 disposed around the portion 14.
The LED mounting substrate 20 and the reflecting member 30 are sequentially stacked on the inner bottom portion 13. The outer light guide 43 of the light guide plate 40 is placed on the outer bottom 15.

The flange portion 12 is joined to the side wall portion 52 of the diffusion cover 50 using, for example, an adhesive or a seal member, in the vicinity of the top portion in the Z direction.
[LED mounting board 20]
The LED mounting substrate 20 includes an annular substrate body 21, a plurality of light emitting elements 22 mounted on the surface of the substrate body 21 (an upper surface facing the reflecting member 30 in FIG. 3), and wirings 23.

The substrate body 21 has, for example, a two-layer structure in which an insulating layer made of a ceramic material or a heat conductive resin and a metal layer made of aluminum or the like are laminated. A wiring pattern (not shown) for electrically connecting the light emitting element 22 and the wiring 23 is formed on the surface of the substrate body 21. The outer diameter of the substrate body 21 is substantially matched with the inner diameter of the side wall portion 14.
The light emitting element 22 uses an LED element as an example. As shown in a partial sectional view (FIG. 7) showing the configuration around the light incident portion 42, as a specific configuration, the light emitting element 22 includes an element main body 220 and an element housing 221 that houses the element main body 220. The light-emitting elements 22 are mounted circumferentially at a constant interval so that the main emission direction faces the vertical (Z) direction with respect to the upper surface of the substrate body 21. In the LED mounting substrate 20, for example, a total of 18 light emitting elements 22 are mounted face-up on a wiring pattern using a COB (Chip on Board) technique.

The upper surface of the substrate body 21 is a reflecting surface for efficiently reflecting the emitted light of the light emitting element 22 toward the light guide plate 40 side.
The wiring 23 is used to supply power to the light emitting element 22 from the power supply unit 4 side. Both ends of the wiring 23 are electrically connected to the wiring pattern of the substrate body 21 and the power supply unit 4.
[Reflection member 30]
The reflection member 30 is a plate-like member that is disposed for the purpose of efficiently reflecting the light emitted from the light emitting element 22 and the light leaking from the light guide plate 40 toward the light guide plate 40. In the instrument 1, the reflective member 30 is sandwiched between the LED mounting substrate 20 and the light guide plate 40. The reflection member 30 is configured using a material having high reflection characteristics, for example, a high light reflection polybutylene terephthalate (PBT) resin, a high reflection polycarbonate (PC) resin, a high light reflection nylon resin, a high light reflection foamed resin, or the like. . By reflecting and molding the reflecting member 30 using these resin materials, the reflecting member 30 can be configured with high accuracy. The reflection member 30 should just have a reflective characteristic in the surface at least.

  Partial perspective sectional view of the instrument 1 (FIG. 4), partial perspective sectional view of the reflecting member 30 (FIG. 5), a top view of the reflecting member 30 (FIG. 6A) and a bottom view (FIG. 6B) As shown in FIG. 6, the reflecting member 30 includes an inner reflecting portion 31, a recessed portion 32, and an outer reflecting portion 33 from the center side toward the outer side. The outer diameter of the reflecting member 30 is substantially matched with the inner diameter of the side wall portion 14. The inner reflection part 31 and the outer reflection part 33 have upper surfaces 310 and 320, respectively (FIG. 5).

The inner reflection part 31 (outer reflection part 33) is provided corresponding to a position on the inner side (outer side) than the mounting position of the light emitting element 22 of the LED mounting substrate 20 (FIG. 4). The inner reflection part 31 (outer reflection part 33) is a part for reflecting light leaking from the light guide plate 40 to the light guide plate 40 side again on the upper surface 310 (320).
The recessed portion 32 is provided in a region corresponding to the position immediately above the mounting position of each light emitting element 22 on the LED mounting substrate 20. When the reflecting member 30 is viewed in plan, the recessed portion 32 is formed by recessed a circumferential region having a constant radius on the upper surface of the reflecting member 30 (the surface facing the light guide plate 40) in the thickness (Z) direction (FIG. 5). ).

  As shown in FIGS. 5, 6 (a), and 6 (b), a plurality of openings 34 penetrating in the thickness direction of the reflecting member 30 are arranged along the circumferential direction inside the recessed portion 32. Exist. The opening 34 has a first opening 340 and a pair of second openings 341 communicating with the first opening 340. In one opening 34, the first opening 340 and the pair of second openings 341 intersect a second direction (for example, the Y direction) that intersects a first direction (for example, the Y direction) passing through the diameter of the reflecting member 30. (X direction orthogonal to each other).

Here, when the reflecting member 30 is viewed in plan, the maximum diameter of the first opening 340 is smaller than the minimum diameter of the second opening (FIG. 5A). Therefore, the opening 34 has a so-called bowl-shaped peripheral shape in which the first opening 340 has a small diameter and the pair of second openings 341 has a large diameter.
The first opening 340 exists immediately above the mounting position of the light emitting element 22 of the LED mounting substrate 20. In the first opening 340, along the Y direction, the peripheral edge 342A, 343A are close to each other at a relatively narrow opening width W ₂ (Figure 7). This is set so as to guide the light to the light guide plate 40 side in the first opening 340 appropriately controlled so that the amount of light emitted from the light emitting element 22 does not become excessive. On both sides of the first opening 340 along the Y direction, there are a pair of side walls 342 and 343 that reflect the emitted light of the light emitting element 22. As shown in FIG. 7, the side walls 342 and 343 exist outside the peripheral edge portions 342A and 343A of the first opening 340 along the Y direction. Thereby, the space of the recessed portion 32 is ensured between the light incident portion 42 of the light guide plate 40 and the side walls 342 and 343. The peripheral edge portions 342A and 343A are formed to have a curved cross-sectional shape with a cross-sectional shape in the YZ direction of about R = 0.2, for example.

The second opening 341 is present in order to efficiently diffuse the light emitted from the light emitting element 22 to a region far from the light emitting element 22. When the reflecting member 30 is viewed in plan, the width of the second opening 341 is set to increase as the distance from the first opening 340 increases in the direction intersecting the direction of communication with the first opening 340 (see FIG. 5 (a)).
As shown in FIG. 6B, the back surface of the reflecting member 30 is a flat surface that matches the surface shape of the substrate body 21 of the LED mounting substrate 20.
[Light guide plate 40]
The light guide plate 40 is used to guide light emitted from the light emitting element 22 mainly in the XY plane direction and to emit light to the diffusion cover 50 (Z direction) side. The light guide plate 40 is disposed on the opposite side of the reflecting member 30 from the side facing the LED mounting substrate 20. Examples of the material of the light guide plate 40 include materials having excellent translucency, such as acrylic resin, polycarbonate resin, polystyrene resin, and glass. By injection-molding the light guide plate 40 using these materials, the light guide plate 40 can be configured with high accuracy in the same manner as the reflecting member 30. Accordingly, the positional relationship between the reflecting member 30 and the light guide plate 40 can be reduced to such an extent that the misalignment error can be ignored. The light guide plate 40 includes an inner light guide part 41, a light incident part 42, and an outer light guide part 43 from the center side toward the outer side (FIG. 3). The outer diameter of the light guide plate 40 is substantially matched with the inner diameter of the side wall portion 14. In the light guide plate 40, as an example, the outer surfaces of the inner light guide part 41 and the outer light guide part 43 are set to the same height (FIG. 4). The thicknesses of the inner light guide 41 and the outer light guide 43 are also set to be the same.

The inner light guide 41 (outer light guide 43) guides the light of the light emitting element 22 that has entered the light guide plate 40 from the light incident part 42 to the inner side (outer side) of the mounting position of the light emitting element 22. It is a site to diffuse.
The light incident part 42 is a part that guides the emitted light of the light emitting element 22 to the light guide plate 40 side. In the instrument 1, the light incident portion 42 is inserted into the recessed portion 32 of the reflecting member 30 (FIG. 4). Thereby, the light incident part 42 is continuously formed so as to connect the mounting positions of the light emitting elements 22 on the LED mounting substrate 20. As a specific configuration, as shown in FIG. 7, the light incident portion 42 includes an element facing portion 420, a pair of inclined portions 422A and 422B, and a boundary portion 423 existing between the pair of inclined portions 422A and 422B. . As shown in FIGS. 4 and 7, the light incident portion 42 has a substantially V-shaped cross-sectional shape having a certain thickness as shown in FIGS. 4 and 7. Side surfaces 424A and 424B having inclined surfaces similar to the inclined portions 422A and 422B exist on the opposite sides of the inclined portions 422A and 422B on both sides of the light incident portion 420 along the Y direction (FIG. 7).

The element facing portion 420 is a part that is disposed in proximity to the light emitting element 22 and is disposed to face the emission surface of the light emitting element 22. The surface shape of the element facing portion 420 facing the light emitting element 22 is a flat surface as an example here. Accordingly element facing portion 420 along the Y direction, having an end positioned on both sides of the width W ₁ (light input end 420A, 420B) (Fig. 7).
The pair of inclined portions 422A and 422B are disposed on the surface of the light guide plate 40 opposite to the surface on which the element facing portion 420 is formed (upper surface in FIG. 7). Specifically, the inclined portions 422A and 422B have inclined surfaces in which the inclination angle smoothly increases with increasing distance from the element facing portion 420 in the vertical (Z) direction. Further, the inclined portions 422A and 422B have shapes that are substantially line symmetrical with respect to the vertical (Z) direction. The inclined portions 422A and 422B have the inclined surfaces as described above, so that incident light incident along the (Z) direction directly above the element facing portion 420 is regularly reflected on the surface thereof and efficiently guided into the light guide plate 40. Can be lighted.

The boundary portion 423 is a minute region that exists between the inclined portions 422A and 422B in correspondence with the mounting position of the light emitting element 22. In the light guide plate 40, the size of the boundary portion 423 is made as small as possible. Thus, the light emitted from the light emitting element 22 is adjusted so as not to directly pass through the boundary portion 423 when the device 100 is driven.
Here, as a feature of the device 100, when the light guide plate 40 is viewed in plan, both end portions (light incident end portions 420A and 420B) of the element facing portion 420 in the first (Y) direction along the surface of the LED mounting substrate 20 are used. The width W ₁ between them is set larger than the opening width W _{2 of the} opening 34 (FIG. 7). Further, in the first (Y) direction, the peripheral edge portions 342A and 343A of the opening 34 are located inside the light incident end portions 420A and 420B. That is, in the instrument 1, when the light guide plate 40 and the reflection member 30 are viewed from the vertical (Z) direction, the first opening 340 is completely covered with the element facing portion 420.

Further, the side walls 342 and 343 are arranged along the Y direction with one of the peripheral edge portions 342A and 343A of the first opening 340 and one of the light incident end portions 420A and 420B adjacent thereto. (See the outgoing lights L ₂ and L ₄ in FIG. 9A).
[Diffusion cover 50]
The diffusion cover 50 is disposed for the purpose of obtaining surface light emission with a uniform luminance distribution by further scattering the light emitted from the light guide plate 40. The diffusion cover 50 is configured using a translucent material such as a silicone resin, an acrylic resin, a polycarbonate resin, or glass.

As a specific configuration, the diffusion cover 50 includes a main body 51 that covers the light guide plate 40 and a side wall 52 that is disposed on the periphery of the main body 51 (FIG. 3).
The main body 51 is subjected to a light scattering process, and is adjusted so as to efficiently scatter the light emitted from the light guide plate 40. As the light scattering treatment, for example, the surface of the main body 51 that faces the light guide plate 40 is subjected to fine uneven processing.
(Operation of apparatus 100)
When the user uses the apparatus 100 having the above configuration, the apparatus 100 is powered on. In the apparatus 100, power is supplied to each light emitting element 22 through the wiring 23 from the power supply unit 4 connected to a commercial power supply. Thereby, outgoing light is generated from each light emitting element 22.

The light emitted from the light emitting element 22 enters the light guide plate 40 from the light incident portion 42 through the first opening 340 and the second opening 341 of the reflecting member 30. Incident light repeats regular reflection inside the light guide plate 40 and diffuses into both the inner light guide 41 and the outer light guide 43. Further, the light leaking downward from the light guide plate 40 is reflected on the upper surfaces 310 and 320 (FIG. 5) of the reflecting member 30 and is incident on the light guide plate 40 side again. The light emitted from the light emitting element 22 diffused by the light guide plate 40 is emitted from the upper surface side of the light guide plate 40 and enters the diffusion cover 50. Incident light is further diffused by the main body 51 of the diffusion cover 50 that has been subjected to light scattering treatment, and finally emitted as illumination light to the outside.
(Effects produced by the apparatus 100)
When the apparatus 100 is driven, the following effects can be expected.
[1] Effect on Chip Deviation of Light-Emitting Element 22 (i) Specific Effect FIG. 8 is a diagram for explaining an effect exhibited when the mounting position of the light-emitting element 22 occurs in the Y direction in the apparatus 100. It is sectional drawing.

Usually, when the light emitting element 22 is mounted on the substrate body 21 in the LED mounting substrate 20, chip displacement may occur. At present, when the total length of the light emitting element 22 in the Y direction is about 1.5 mm, a chip shift in a range of about ± 0.4 mm can occur.
When the chip shift occurs, the relative position of the light emitting element 22 with respect to the light incident portion 42 also shifts in the direction of the slip. Therefore, the light does not pass through the light incident portion 42 and is not reflected by the side walls 342 and 343 toward the inclined portions 422A and 422B in the regions where the inclination angle with respect to the vertical (Z) direction is relatively low (region far from the element facing portion 420). As a result, the light emitted from the high-intensity light-emitting element 22 entering the light guide plate 42 increases. FIG. 8 shows a state in which emitted light (dotted line) is emitted toward the inclined portion 422B from the light emitting element 22 in which the chip is displaced in the Y direction.

If the high-intensity outgoing light L ₈ is incident on the inclined portion 422B along the dotted line shown in FIG. 8 without passing through the light incident portion 42 and not reflected by the side walls 342 and 343, the inclined portion due to the large angle of incidence on 422B, the outgoing light L ₈ will direct high-luminance light penetrating the inclined portion 422B, which may be emitted to the outside. Therefore, it is assumed that brightness unevenness is caused on the light emitting surface of the instrument 1.

On the other hand, in the instrument 1, the emitted light L ₈ emitted from the light emitting element 22 in the vertical (Z) direction has a first opening portion having an opening width W ₂ narrower than the width W ₁ between the light incident end portions 420A and 420B. It is shielded by the peripheral edge 343A of 340 (FIGS. 7 and 8). As a result, even if the light emitting element 22 is displaced in the Y direction, the high-intensity outgoing light L ₈ that does not pass through the light incident part 42 and is not reflected by the side walls 342 and 343 reaches the inclined part 422B. Is suppressed. Therefore, it is possible to prevent the emitted light L ₈ from penetrating the inclined portion 422B and being emitted to the outside as high-intensity direct light.

Although not shown in FIG. 8, even when a chip shift occurs in the reverse Y direction, the emitted light emitted from the light emitting element 22 to the outside of the light incident part 420 is shielded by the peripheral edge part 342A. Thereby, there exists an effect similar to the above.
As described above, in the instrument 1, even when the mounting position of the light emitting element 22 is displaced along the Y direction or the reverse Y direction, the high-luminance direct light emitted through the inclined portions 422A and 422B is emitted to the outside. Occurrence can be prevented.

Although not shown in FIG. 8, the reflected light reflected by the side walls 342 and 343 may enter the light guide plate 40 from a region other than the light incident portion 420 and may pass through the light guide plate 40 and be emitted to the outside ( (See the light L ₁₃ in FIG. 17A and the light L ₁₅ in FIG. 17B). However, since such light is diffused when reflected by the side walls 342 and 343, the intensity is weak. Therefore, it is difficult to cause uneven brightness.

Even when the chip is displaced, the emitted light (including L ₅ , L ₆ , and L ₇ in FIG. 8) from the light emitting element 22 that is not shielded by the peripheral edge portions 342A and 343A passes through the first opening 340. Then, the light is appropriately incident on the light guide plate 40 from the periphery of the light incident portion 42, and is guided to the inner light guide portion 41 and the outer light guide portion 43 to contribute to light emission. As a result, it is possible to realize the illumination device 100 that can suppress the occurrence of uneven brightness and can expect uniform surface light emission.
(Ii) Performance Confirmation Test The apparatus 100 was actually manufactured as an example, and a performance confirmation test was performed with respect to a pattern of luminance unevenness generated when a chip shift was intentionally generated at a constant interval and an illuminance distribution at that time. .

For comparison with the embodiment, as shown in the illumination device 910 in FIG. 17A, the light incident portion 946X and the light emitting element 922 are arranged to face each other without the opening 34. A device similar to the example was prepared as a comparative example.
The chip deviation between the example and the comparative example is any deviation of -0.1 mm, -0.3 mm, or -0.5 mm when the LED mounting substrate is viewed in plan, with the mounting position of the light emitting element inward from the reference position. It was set when shifting by the amount and when shifting by any of +0.1 mm, +0.3 mm, and +0.5 mm outside the reference position. The positional deviation at each numerical value was set for all the light emitting elements on the LED mounting substrate. The devices of the example and the comparative example were driven under the same conditions. The confirmation test results are shown in FIGS.

FIG. 10 and FIG. 11 show the luminance unevenness pattern and the illuminance distribution at that time when chip displacement occurs in the comparative example and the example in the same order. Each of the uneven brightness patterns in each figure is shown by a photograph taken from the front of the light emitting surface of the apparatus. The illuminance distribution indicates the relative intensity distribution in the radial direction of the light emitting surface.
Looking at the test results, in the comparative example, as shown in FIG. 10, the illuminance distribution becomes more uneven as the amount of deviation increases even if the chip deviation occurs in either the inside or outside direction of the LED mounting substrate with respect to the reference position. Became. When the illuminance distribution becomes non-uniform, it means that uneven brightness in surface light emission can occur. Further, there was a tendency that as the deviation amount was larger, an unnecessary high-brightness peak was generated in the illuminance distribution (for example, refer to data with a chip deviation of −0.5 mm and +0.5 mm). In addition, when the light emitting surface of the device of the comparative example was viewed from the front, the light emitting region changed greatly when chip displacement occurred. It was confirmed that the central area of the light emitting surface was reduced and the luminance was insufficient as the amount of deviation increased. Furthermore, it was confirmed that a ring-shaped high luminance region was generated at the periphery of the light emitting surface as the deviation amount increased, and luminance unevenness became remarkable. Note that the position of the high luminance unevenness on the light emitting surface and the position of the peak of the illuminance distribution coincide with each other.

  On the other hand, in the embodiment, as shown in FIG. 11, the luminance unevenness generated in the illuminance distribution is larger than that in the comparative example even when the chip shift occurs in any direction inside or outside the LED mounting substrate with respect to the reference position. It was confirmed to be small. When the light emitting surface of the device is viewed from the front, the change in the light emitting region due to the amount of deviation is appropriately suppressed. It should be noted that when the chip deviation is greatly increased, a slight luminance unevenness is observed, but it has been found that, as a whole, much more uniform surface light emission is realized as compared with the comparative example.

From the above results, the superiority of the example over the comparative example could be confirmed.
[2] In effect device 100 according to the first opening 340, when the light emitted from the light emitting element 22 passes through the first opening 340, the peripheral edge of the first opening 340 342A having a width W _2, in 343A The emitted light is partially blocked (FIG. 7). Thereby, the emitted light quantity which passes the 1st opening part 340 from the mounting position of the light emitting element 22 is controlled so that it may not become excessive.

Therefore, when the instrument 1 is viewed from the front, the amount of emitted light is appropriately regulated from the mounting position of the light emitting element 22. As a result, the luminance distribution unevenness in the region corresponding to the mounting position of the light emitting element 22 and the region corresponding to the other position on the outer surface of the diffusion cover 50 is suppressed, which can contribute to the realization of good surface light emission. .
[3] Effects of the side walls 342 and 343, the peripheral edge portions 342A and 343A, and the light incident end portions 420A and 420B The apparatus 100 passes between the light incident end portion 420A (420B) and the peripheral edge portion 342A (343A). The light emitted from the light emitting element 22 (hereinafter referred to as “passing light”) is all reflected by the surfaces of the side walls 342 and 343 of the reflecting member 30 and then enters the light incident portion 42 of the light guide plate 40 ( FIG. 9A). The effect exhibited at this time will be described with reference to a partial sectional view around the light incident portion 42 (FIG. 9A) and an enlarged sectional view of the light emitting element 22 (FIG. 9B).

The exit angle θ ₁ shown in FIG. 9B is emitted from the position of the light emitting element 22 farthest from the light incident end 420A (420B) along the Y direction, and is in contact with the light incident end 420A (420B). This is the emission angle of the incident light L ₁ (L ₃ ). The emission angle θ ₂ is an emission angle of the outgoing light L ₂ (L ₄ ) in contact with the peripheral edge portion 342A (343A) and the light incident end portion 420A (420B) along the Y direction. Instrument 1, the peripheral edge 342A, 343A and the light incident end 420A, by adjusting the positional relationship between 420B, the passing light having the emission angle theta ₁ or θ2 less. The emission angle between θ _{1 and} θ ₂ can be set as appropriate. For example, θ1 is 25 ° and θ2 is 50 °.

Thereby, the passing light strikes the surfaces of the side walls 342 and 343 and enters the light guide plate 40 as reflected light. The outgoing light reflected by the side walls 342 and 343 is incident at a sufficiently small incident angle on the vicinity of the inclined portions 422A and 422B (FIG. 9A). The outgoing lights L _{1 to} L ₄ are specularly reflected in the vicinity of the inclined portions 422A and 422B, and are guided well over the entire interior of the light guide plate 40.

By such a device, it is possible to prevent the passing light from passing through the vicinity of the inclined portions 422A and 422B to become direct light with a large amount of light and to be emitted to the outside.
As shown in FIG. 8, even if the mounting position of the light emitting element 22 is slightly displaced, the passing light is inclined part 422A as in the case of the emitted light L ₅ , L ₆ , L _7. The incident angle is sufficiently small with respect to 422B. Therefore, the above-described effect can be expected even when a chip shift occurs.
[4] Effect of Combined Use of First Opening 340 and Second Opening 341 In the device 100, when the light emitted from the light emitting element 22 passes through the second opening 341, the second opening 341 is the first opening. By having a diameter larger than the maximum diameter of the portion 340, it is possible to allow the second opening 341 to pass light having an abundance of emitted light that is relatively richer than the amount of emitted light that passes through the first opening 340.

  As a result, the light emitted from each light emitting element 22 is uniformly dispersed along the circumferential recess 32. When the diffusion cover 50 of the instrument 1 is viewed from the outside, a high-luminance light-emitting area corresponding to the mounting position of the light-emitting element 22 and a low-luminance light-emitting area corresponding to the position where the light-emitting element 22 is not mounted are mixed. Are prevented from occurring. Therefore, it is possible to expect uniform surface light emission while suppressing occurrence of luminance unevenness.

Here, FIG. 12A shows a surface emitting illumination device 910 of a comparative example in which the reflecting member does not have the opening 34 (the same as the illumination device 910 shown in FIGS. 17A and 17B). It is a typical front view at the time of driving. FIG. 12B is a photograph taken from the front of the state of the light emitting surface when the lighting device 910 is driven.
As shown in FIG. 12A, the amount of light emitted from the light emitting element 922 is relatively large in the vicinity of the mounting position of the light emitting element 922 between the inner reflecting portion 945b and the outer reflecting portion 945a of the reflecting member 945. For this reason, as shown in the enlarged view of FIG. 12A, a light emitting region D ₂ having a relatively high luminance exists in the vicinity of the mounting position of the light emitting element 922. On the other hand, in the vicinity of the light emitting region D ₂ due to the lack of amount of light emitted from the light emitting element 922, a relatively low-luminance light emission region D _1, D ₃ is present. Since a plurality of light emitting elements 922 circumferentially in the lighting apparatus 910 is mounted at a distance, the light emitting region D ₁ to D ₃ are combined in mounting positions of the light emitting element 922, the circumferential outside surface of the diffusion cover 50X Appear repeatedly. Therefore, when the illumination device 910 is driven, as shown in FIG. 12B, luminance unevenness may occur in a circumferential shape on the light emitting surface.

On the other hand, FIG. 13A is a schematic front view when the apparatus 100 is driven. FIG. 13B is a photograph taken from the front of the state of the light emitting surface when the device 100 is driven.
As shown in FIG. 13A, at the mounting position of the light emitting element 22 existing correspondingly between the inner light guide part 41 and the outer light guide part 43 of the light guide plate 40, the emitted light quantity is narrow and the first. It is regulated by the opening 340. On the other hand, the wide second opening 341 communicating with the first opening 340 has a diameter larger than the maximum diameter of the first opening 340, and thus the emitted light from the light emitting element 22 passes abundantly. Therefore, on the outer surface of the diffusion cover 50, as shown in the enlarged view of FIG. 13A, the light emitting region C ₂ corresponding to the first opening 340 and the light emitting region C ₁ corresponding to the second opening 341, luminance distribution in C ₃ Metropolitan is uniform. Therefore, when the device 100 is actually driven, as shown in FIG. 13B, substantially uniform surface light emission can be obtained on the light emitting surface.
<Other embodiments>
Another embodiment of the present invention will be described with reference to FIGS. 14A to 14D focusing on differences from the first embodiment.

FIG. 14A is a diagram showing the shape of the opening 34A provided in the reflecting member according to the second embodiment. The opening 34A has the basic structure of the opening 34 of the first embodiment, and the peripheral edge of the pair of second openings 341A communicating with the first opening 340A in one direction (left and right direction on the paper surface) is formed at an acute angle. It has the characteristic which is.
The effect similar to that of the opening 34 of the reflecting member 30 of the first embodiment can be expected also by the opening 34A according to the second embodiment. In addition, since the opening 34A has a configuration in which the width of the second opening 341A gradually increases as the distance from the first opening 340A increases, more emitted light is secured in the region of the second opening 341A that is far from the first opening 340A. And it can be made to emit smoothly.

FIG. 14B is a diagram illustrating the shape of the opening 34 </ b> B provided in the reflecting member according to the third embodiment. The opening 34 </ b> B has a pair of peripheral edges in which the first opening 340 </ b> B is parallel to one direction (left and right direction in the drawing). Further, the opening 34B has a pair of rectangular second openings 341B communicating with the first opening 340B.
The same effect as in the first embodiment can also be expected by the opening 34B according to the third embodiment. Further, in the opening 34B, the width of the second opening 341B is rapidly increased as the distance from the first opening 340B increases. For this reason, a relatively large ratio of the amount of light emitted from the second opening 341B to the first opening 340B can be ensured.

FIG. 14C shows the shape of the opening 34 </ b> C provided in the reflecting member according to the fourth embodiment. The opening 34C has a basic configuration according to the third embodiment, and has a pair of second openings 341C communicating with the first opening 340C in a circular shape.
The effect similar to that of the third embodiment can also be expected by the opening 34C according to the fourth embodiment. In addition, since there is no corner on the periphery of the second opening 341C, the emitted light from the second opening 341C has excellent uniformity.

FIG. 14D shows the shape of the opening 34 </ b> D provided in the reflecting member according to the fifth embodiment. The opening 34D has a basic configuration according to the third embodiment, and has a shape in which the peripheral edges of the pair of second openings 341D communicating with the first opening 340D are enlarged in a step shape as the distance from the first opening 340D increases. It is.
The same effect as in the third embodiment can also be expected by the opening 34D according to the fifth embodiment. Furthermore, the amount of light emitted from the second opening 341D can be precisely adjusted by appropriately adjusting the width of the second opening 341D in steps.

14 (a) to 14 (d) show only one opening, it goes without saying that a plurality of these openings can exist in the reflecting member of each embodiment.
FIG. 15 is a partial cross-sectional view around the light incident portion 42 showing the configuration of the light incident portion 42A in the instrument 1A according to the sixth embodiment. The difference between the instrument 1A and the instrument 1 is that, in the light guide plate 40A, the shape of the element facing portion 420C is a gentle curved surface along the YZ cross section.

Even in the instrument 1A having such a configuration, the same effect as in the first embodiment can be expected. Further, since the cross-sectional shape of the element facing portion 420C is a curved surface, the incident angle when the emitted light from the light emitting element 22 strikes the element facing portion 420C can be reduced. As a result, the reflected light generated at the element facing portion 420C increases, and the amount of incident light that is reflected by the side walls 342 and 343 and incident on the light guide plate 40 increases. As a result, it is possible to increase the amount of light guided to the entire light guide plate 40A.
<Other matters>
The lighting device according to the present invention is not limited to a ceiling light embedded in a ceiling. In addition to ceiling lights installed by other installation methods, it can be widely used for lighting applications such as downlights and backlights.

In the present invention, the latch member 3 is not essential. The luminaire 1 may be fixed to the ceiling using screws, rivets, adhesion, or the like.
In the apparatus 100, although the power supply unit 4 and the lighting fixture 1 were comprised separately, this invention is not limited to this structure. That is, the illuminating device of the present invention may be configured such that the luminaire 1 includes the power supply unit 4 therein.

The light emitting element according to the present invention may be, for example, an LD (laser diode) or an EL element (electric luminescence element). The light emitting device according to the present invention may be an SMD (Surface Mount Device) type.
In the lighting device according to the present invention, the diffusion cover is not essential.
In the above embodiment, the reflecting member 30 is configured as an integral type. However, in the present invention, adjacent openings 34 may communicate with each other. In this case, the reflecting member 30 can be composed of two members, an inner reflecting portion 31 and an outer reflecting portion 33.

In the reflecting member of the present invention, the recessed portion is not essential. What is necessary is just to arrange | position a light-incidence part in the position corresponding to opening of a reflection member. However, the total thickness of the reflection member and the light guide plate can be reduced by inserting the light incident portion into the recessed portion. Therefore, it can contribute to the downsizing of the instrument.
The light guide plate may have a flat surface facing the reflection member, but a plurality of minute lenses may be provided to change the reflection characteristics of light passing through the light guide plate. Thereby, the light guide effect of the light guide plate can be improved.

In each said embodiment, the reflection member 30 was illustrated as a plate-shaped member provided above the LED mounting substrate 20. FIG. However, in the present invention, the configuration of the plate member is not limited to the reflecting member. That is, the plate-like member can be configured not to have reflectivity.
In each said embodiment, although the instrument is disk shape, an instrument is not limited to this shape. For example, the LED mounting substrate may be configured by arranging a plurality of light emitting elements on a long substrate body. In this case, the base, the reflection member, the light guide plate, and the light guide cover are configured to be long like the LED mounting substrate. Thereby, an instrument can also be made long.

DESCRIPTION OF SYMBOLS 1, 1A LED lighting fixture 2 Ceiling 4 Circuit unit 10 Base 20 LED mounting board 21 Substrate body 22 Light emitting element 30, 945X Reflective member 31 Inner reflection part 32 Recessed part 33 Outer reflection part 34, 34A-34D Opening 40, 40A, 940X Light guide plate 41 Inner light guide part 42, 42A, 946X Light incident part 43 Outer light guide part 50 Diffusion cover 51 Main body part 100, 900, 910 LED lighting device 220 Element main body 221 Element housing 310, 320 Upper surface 340 of reflecting member 340A to 340D First opening portion 341, 341A to 341D Second opening portion 342, 343 Side wall 342A, 343A First opening peripheral edge portion 420, 420C, 947X Element facing portion 420A, 420B Light incident end portion 422A, 422B, 948X, 949X inclined part 423 boundary part 4 4A, 424B, 950X, 951X side portions

Claims (15)

A mounting board on which a plurality of light emitting elements are mounted, a light guide plate that guides light emitted from each light emitting element, and a position that is sandwiched between the mounting board and the light guide plate and corresponds to each light emitting element And a plate-like member having an opening penetrating in the thickness direction.
The light guide plate has a light incident portion where light emitted from the light emitting element is incident through the opening at a position corresponding to the opening.
The light incident portion is opposed to the element in a first direction along the surface of the mounting substrate on an element facing portion facing the light emitting element and on a surface opposite to a surface where the element facing portion of the light guide plate exists. An inclined portion with an inclined surface that increases in inclination angle with respect to a direction perpendicular to the surface of the mounting substrate as it is further from the portion;
When the light guide plate is viewed in plan, the width of the opening is smaller than the width of the element facing portion along the first direction, and both end portions of the periphery of the opening are inside of both end portions of the element facing portion. Located in the lighting device. The plate-like member has a recessed portion formed by recessed the surface, and the opening exists inside the recessed portion,
The lighting device according to claim 1, wherein the light incident portion is inserted into the recessed portion. Along the first direction, the light incident portion has the inclined portion at each position corresponding to the both end portions of the element facing portion, and the inclination of the surface of each inclined portion is greater than that of the element facing portion. The lighting device according to claim 1, wherein the lighting device gradually decreases as the distance increases. The opening has a first opening that exists at a position corresponding to the light emitting element, and a second opening that communicates with the first opening and has a diameter larger than the maximum diameter of the first opening. ,
The illuminating device according to any one of claims 1 to 3, wherein the light incident portion is disposed close to a position corresponding to the first opening. The lighting device according to any one of claims 1 to 4, wherein the plate-like member is a reflecting member that reflects light emitted from the light emitting element. Along the first direction, the reflecting member has side walls on both sides sandwiching the first opening inside the recessed portion, and each of the side walls is one of both end portions of the peripheral edge of the first opening. The illuminating device according to claim 5, wherein the illumination device is disposed on a straight line that connects either one of the two ends of the peripheral edge of the light incident portion adjacent thereto. The lighting device according to claim 6, wherein the pair of side walls exist outside the both ends of the peripheral edge of the first opening along the one direction. The lighting device according to any one of claims 4 to 7, wherein in a second direction orthogonal to the first direction, a pair of the second openings are provided on both sides of the first opening so as to communicate with each other. The plurality of light emitting elements are mounted at intervals from each other,
The lighting device according to claim 4, wherein the second opening is present at a position corresponding to a position between mounting positions of the adjacent light emitting elements. The plurality of light emitting elements are mounted on the surface of the mounting substrate in a circumferential shape,
The lighting device according to claim 1, wherein the light incident portion of the light guide plate is continuously formed so as to connect the mounting positions of the light emitting elements on the mounting substrate. The light guide plate has a disc shape, and has a first light guide part located inside the light incident part, and a second light guide part located outside the light incident part,
The lighting device according to claim 10, wherein the first direction is a direction passing through a diameter of the light guide plate. The outer surfaces of the first light guide and the second light guide are the same height,
The lighting device according to claim 11, wherein the first light guide unit and the second light guide unit have the same thickness. The lighting device according to claim 1, wherein the plate member and the light guide plate are injection-molded. The lighting device according to claim 1, wherein the light emitting element is an LED element. The lighting device according to claim 1, further comprising a power supply device for supplying power to the light emitting element.