JP2018029044A - lighting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide lighting equipment capable of enhancing the utilization efficiency of light from a luminous element.SOLUTION: Lighting equipment 2 comprises a second luminous element 46 and a light guide plate 22 for guiding a light from the second luminous element 46 into a predetermined direction. The light guide plate 22 includes: an incident part 22c, in which a light from the second luminous element 46 is incident; an outgoing radiation part 22d, from which the light incident upon the incident part 22c emanates; and a light guide part 22b extending in a curvature from the incident part 22c to the outgoing radiation part 22d, and having a first reflection plane 70 and a second reflection plane 72 on an outer peripheral surface. The first reflection plane 70 forms a parabola having a focal point F in a section at the time when a light output part 22b is cut in a virtual plane. The second reflection plane 72 is arranged in a section on the side closer to the outgoing radiation part 22d than the first reflection plane 70, and is arranged at a position intersecting the virtual straight lines 76 and 78 extending through the first reflection plane 70 and the focal point F.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a lighting fixture using a light guide plate.

  A lighting fixture using a light guide plate is known (see, for example, Patent Document 1). The light guide plate includes an incident part where light from the light emitting element is incident, an emission part from which light incident on the incident part is emitted, and a light guide part formed between the incident part and the emission part. The light guide portion extends while being curved from the entrance portion to the exit portion. The light incident on the light guide from the incident part is guided toward the emission part while being reflected by the outer peripheral surface (convex surface) of the light guide.

JP 2013-101858 A

  However, in the above-described conventional lighting fixture, a light propagation loss occurs in the light guide unit, which causes a problem that the light use efficiency from the light emitting element is reduced.

  This invention is made | formed in view of such a subject, and it aims at providing the lighting fixture which can improve the utilization efficiency of the light from a light emitting element.

  In order to solve the above-described problem, a lighting fixture according to one embodiment of the present invention includes a light emitting element and a light guide plate for guiding light from the light emitting element in a predetermined direction, and the light guide plate includes the light emitting element. An incident portion where light from the element is incident, an emission portion from which light incident on the incident portion is emitted, and a light guide portion formed between the incident portion and the emission portion, from the incident portion A light guide section that extends while curving to the emission section, and has a first reflection surface and a second reflection surface on the outer peripheral surface for guiding the light incident on the incidence section while reflecting the light toward the emission section; The first reflective surface forms a parabola having a focal point in a cross section when the light guide section is cut along a virtual plane, and the second reflective surface has the first reflective surface in the cross section. The first reflection surface is disposed closer to the emitting portion than the reflection surface of the first reflection surface. They are arranged at positions intersecting the virtual straight line passing through said focal point.

  According to the lighting fixture which concerns on 1 aspect of this invention, the utilization efficiency of the light from a light emitting element can be improved.

It is a perspective view which shows the external appearance by the side of the floor surface of the lighting fixture which concerns on embodiment. It is a perspective view which shows the external appearance of the ceiling side of the lighting fixture which concerns on embodiment. It is a disassembled perspective view which shows the lighting fixture which concerns on embodiment in the state which removed the diffusion cover. It is a disassembled perspective view which shows the lighting fixture which concerns on embodiment in the state which removed the decorative cover, the light-guide plate, and the reflection member. It is a disassembled perspective view which decomposes | disassembles and shows the lighting fixture which concerns on embodiment. It is the VI-VI sectional view taken on the line of FIG. It is sectional drawing which expands and shows a part of FIG. It is a top view which shows the lighting fixture which concerns on embodiment in the state which abbreviate | omitted the decorative cover, the light-guide plate, the reflection member, and the diffusion cover. It is a top view which shows the lighting fixture which concerns on embodiment in the state which further omitted the lens cover from FIG. It is a figure which extracts and shows the light-guide plate which concerns on embodiment. It is the XI-XI sectional view taken on the line of (a) of FIG. It is a cross-sectional perspective view which expands and shows the incident part of the light-guide plate which concerns on embodiment. It is a perspective view which expands and shows a part of light-guide plate which concerns on the modification of embodiment.

  Embodiments of the present invention will be described below. Note that each of the embodiments described below shows a preferred specific example of the present invention. Therefore, numerical values, shapes, materials, components, arrangement positions and connection forms of the components, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. In each figure, substantially the same configuration is denoted by the same reference numeral, and redundant description is omitted or simplified.

(Embodiment)
Hereinafter, the lighting fixture which concerns on embodiment is demonstrated.

[1. Configuration of lighting equipment]
[1-1. Overall configuration of lighting equipment]
First, the whole structure of the lighting fixture 2 which concerns on embodiment is demonstrated, referring FIGS. FIG. 1 is a perspective view showing an external appearance of a floor surface side of a lighting fixture 2 according to an embodiment. FIG. 2 is a perspective view showing an external appearance of the lighting fixture 2 according to the embodiment on the ceiling 4 side. FIG. 3 is an exploded perspective view showing the luminaire 2 according to the embodiment with the diffusion cover 26 removed. FIG. 4 is an exploded perspective view showing the lighting fixture 2 according to the embodiment with the decorative cover 20, the light guide plate 22, and the reflection member 24 removed. FIG. 5 is an exploded perspective view showing the lighting fixture 2 according to the embodiment in an exploded manner.

  The lighting fixture 2 is a ceiling light that is installed on a ceiling 4 (see FIG. 5) of a building such as a house and illuminates a space 6 (see FIG. 6 described later) inside the building. As shown in FIGS. 1 to 5, the lighting fixture 2 includes a fixture body 8, a fixture mounting member 10, a power supply unit 12, a reflective cover 14, a light emitting module 16, a lens cover 18, a decorative cover 20, a light guide plate 22, and a reflective member. 24 and a diffusion cover 26 are provided.

  Hereinafter, each component of the lighting fixture 2 is demonstrated in detail, referring FIGS. 1 to 12, the minus side of the Z axis represents the ceiling 4 side, and the plus side of the Z axis represents the floor (not shown) side. For convenience of explanation, in FIG. 1 and FIGS. 3 to 7, the lighting fixture 2 is illustrated in an upside down posture from the posture during normal use.

[1-2. Instrument body]
The instrument body 8 will be described with reference to FIGS. 2, 5, 6 and 7. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is an enlarged cross-sectional view showing a part of FIG.

  The instrument main body 8 is a housing for supporting the power supply unit 12 and the reflective cover 14. As shown in FIGS. 2, 5, and 6, the instrument body 8 is formed in a ring shape having a circular opening 8a at the center. As shown in FIGS. 5 and 7, a flange portion 8 b for supporting the reflective cover 14 is formed on the outer peripheral portion of the instrument body 8. In addition, the instrument main body 8 is shape | molded in the shape mentioned above by pressing a sheet metal, such as an aluminum plate or a steel plate, for example.

  As shown in FIG. 6, a holder 28 for attaching the instrument body 8 to the instrument mounting member 10 (described later) is fixed to the peripheral edge of the opening 8 a of the instrument body 8. The holder 28 extends from the peripheral edge of the opening 8a of the instrument body 8 to the floor surface side. As will be described later, the instrument mounting member 10 is detachably fitted inside the holder 28.

  Further, as shown in FIGS. 5 and 6, an insulating case 30 for supporting the reflective cover 14 is fixed to one surface (floor surface) of the instrument body 8. The insulating case 30 is formed in a substantially rectangular cylindrical shape, and is disposed at a position surrounding the holder 28. The insulating case 30 is made of an insulating material such as resin.

  Further, as shown in FIGS. 2 and 6, a plurality of cushion members 32 made of urethane or the like are attached to the other side surface (the surface on the ceiling 4 side) of the instrument body 8. The plurality of cushion members 32 are arranged at equal intervals along the circumferential direction of the instrument body 8. When the lighting fixture 2 is installed on the ceiling 4 as will be described later, the plurality of cushion members 32 are sandwiched between the fixture main body 8 and the ceiling 4, thereby suppressing the wobbling of the fixture main body 8.

[1-3. Instrument mounting member]
Next, the instrument mounting member 10 will be described with reference to FIGS. 2, 5, and 6. The instrument attachment member 10 is an adapter for detachably attaching the instrument body 8 to a hooking sealing body 34 (see FIG. 5) installed on the ceiling 4.

  As shown in FIGS. 2, 5, and 6, the instrument mounting member 10 is formed in a substantially cylindrical shape, and is detachably fitted into the holder 28 of the instrument body 8. Moreover, the instrument mounting member 10 is detachably attached to the hooking sealing body 34.

  When installing the lighting fixture 2 on the ceiling 4, the user first hooks the fixture mounting member 10 and attaches it to the ceiling body 34. Thereafter, the user pushes the instrument body 8 toward the ceiling 4 so that the instrument mounting member 10 is inserted into the holder 28 of the instrument body 8, thereby fitting the holder 28 and the instrument mounting member 10 together. . Thereby, the fixture body 8 is attached to the ceiling 4 via the fixture attachment member 10 and the hooking sealing body 34, and the lighting fixture 2 is installed on the ceiling 4.

  The hook ceiling body 34 is electrically connected to a commercial power source (not shown) disposed on the back side of the ceiling 4 via an electric wire (not shown). By installing the luminaire 2 on the ceiling 4, AC power from a commercial power supply is supplied to the luminaire 2 via the electric wire and the hooking sealing body 34.

[1-4. Power supply unit]
Next, the power supply unit 12 will be described with reference to FIG. The power supply unit 12 is a unit for generating electric power for causing the light emitting module 16 to emit light. As shown in FIG. 5, the power supply unit 12 includes a substrate 36 and a plurality of circuit components 38 mounted on the substrate 36.

  The board 36 is a printed wiring board for mounting a plurality of circuit components 38, and is formed in a substantially L shape. The substrate 36 is attached to one surface of the instrument body 8 so that the plurality of circuit components 38 face the floor surface.

  Each of the plurality of circuit components 38 is a power supply circuit component constituting a power supply circuit for generating electric power for causing the light emitting module 16 to emit light. The plurality of circuit components 38 include, for example, a) a capacitive element such as an electrolytic capacitor or a ceramic capacitor, b) a resistive element such as a resistor, c) a rectifier circuit element, d) a coil element, e) a choke coil (choke transformer), f) Noise filter, g) Semiconductor elements such as diodes or integrated circuit elements.

  The plurality of circuit components 38 convert AC power supplied from the commercial power supply described above via electric wires into DC power. When the DC power generated by the plurality of circuit components 38 is supplied to the light emitting module 16, the light emitting module 16 emits light.

  The plurality of circuit components 38 may include not only the above-described power supply circuit components but also circuit components constituting other circuits. For example, the plurality of circuit components 38 may include a driving circuit component that configures a dimming circuit, a booster circuit, or the like, or includes a communication circuit component (communication module) that configures a communication circuit. Also good.

[1-5. Reflective cover]
Next, the reflective cover 14 will be described with reference to FIGS. The reflection cover 14 is a cover for reflecting light from the light emitting module 16. The reflective cover 14 also functions as a heat sink for dissipating heat from the light emitting module 16.

  As shown in FIGS. 4 to 6, the reflection cover 14 is formed in a ring shape having a substantially rectangular opening 14 a at the center. As shown in FIG. 7, a flange portion 14 b is formed on the outer peripheral portion of the reflective cover 14. The reflection cover 14 is formed into the above-described shape by pressing a sheet metal such as an aluminum plate or a steel plate. Note that a white paint is applied or a reflective metal material is deposited on one surface (floor surface) of the reflective cover 14 in order to improve reflectivity and improve light extraction efficiency. .

  As shown in FIGS. 6 and 7, the reflective cover 14 is disposed so as to cover one surface of the instrument body 8. The flange portion 14 b of the reflective cover 14 is attached to the flange portion 8 b of the instrument body 8 with a plurality of screws 40. Further, the peripheral edge of the opening 14 a of the reflective cover 14 is supported by the tip of the insulating case 30.

[1-6. Light emitting module]
Next, the light emitting module 16 will be described with reference to FIGS. FIG. 8 is a plan view showing the luminaire 2 according to the embodiment in a state in which the decorative cover 20, the light guide plate 22, the reflection member 24, and the diffusion cover 26 are omitted. FIG. 9 is a plan view showing the luminaire 2 according to the embodiment in a state in which the lens cover 18 is further omitted from FIG.

  The light emitting module 16 is a light source for emitting white light, for example. As shown in FIGS. 4 to 9, the light emitting module 16 includes a plurality of substrates 42, a plurality of first light emitting elements 44 and a plurality of second light emitting elements 46 (light emitting elements) mounted on each of the plurality of substrates 42. An example of an element).

  As shown in FIG. 9, the substrate 42 is a printed wiring board for mounting the plurality of first light emitting elements 44 and the plurality of second light emitting elements 46, and is formed in an arc shape. Each of the plurality of substrates 42 is attached to one surface of the reflective cover 14 with a screw 48 so as to surround the opening 14 a of the reflective cover 14. Thereby, the some board | substrate 42 is arrange | positioned along with the ring shape along the circumferential direction of the light-guide plate 22 (after-mentioned).

  As shown in FIG. 9, a pair of connectors 50 are mounted on both ends of the substrate 42 in the circumferential direction. A pair of opposing connectors 50 of a pair of adjacent substrates 42 are electrically connected to each other via lead wires 52. In addition, a pair of opposing connectors 50 of another pair of adjacent substrates 42 are electrically connected to the substrate 36 of the power supply unit 12 via lead wires 54.

  As the substrate 42, for example, a resin substrate, a metal base substrate, a ceramic substrate, a glass substrate, or the like can be used. Further, the substrate 42 is not limited to a rigid substrate, and may be a flexible substrate.

  The plurality of first light emitting elements 44 are mounted on the inner peripheral portion of the substrate 42. Specifically, the plurality of first light emitting elements 44 are arranged, for example, in three rows in the radial direction of the substrate 42 in the inner peripheral portion of the substrate 42. In each row, the plurality of first light emitting elements 44 are arranged at intervals in the circumferential direction of the substrate 42. Thereby, as the whole light emitting module 16, the plurality of first light emitting elements 44 are arranged in a ring shape.

  The plurality of second light emitting elements 46 are mounted on the outer peripheral portion of the substrate 42. Specifically, the plurality of second light emitting elements 46 are arranged, for example, in one row at intervals in the circumferential direction of the substrate 42 at the outer peripheral portion of the substrate 42. Thereby, as the whole light emitting module 16, the plurality of second light emitting elements 46 are arranged in a ring shape.

  Each of the first light emitting element 44 and the second light emitting element 46 is, for example, a packaged surface mount device (SMD) type white LED (Light Emitting Diode) element. That is, each of the first light-emitting element 44 and the second light-emitting element 46 includes a white resin package (container) having a recess, an LED chip primarily mounted on the bottom surface of the recess of the package, and a recess in the package. And a sealing member sealed in the container. The LED chip is, for example, a blue LED chip that emits blue light. The sealing member contains a yellow phosphor such as YAG (yttrium, aluminum, garnet) that emits fluorescence using blue light from a blue LED chip as excitation light.

  Thus, each of the 1st light emitting element 44 and the 2nd light emitting element 46 is a white LED element of the BY type comprised by the blue LED chip and the yellow fluorescent substance. Specifically, the yellow phosphor contained in the sealing member is excited by absorbing a part of the blue light from the blue LED chip and emits yellow light. The emitted yellow light and the blue light that is not absorbed by the yellow phosphor are mixed to generate white light. In this way, white light is emitted from each of the first light emitting element 44 and the second light emitting element 46.

  In the present embodiment, both the first light emitting element 44 and the second light emitting element 46 emit white light, but may emit light of different colors (wavelengths). For example, the first light emitting element 44 may emit white light and the second light emitting element 46 may emit light bulb color light.

[1-7. Lens cover]
Next, the lens cover 18 will be described with reference to FIGS. The lens cover 18 is an optical member for expanding the light distribution angle of light from each of the plurality of first light emitting elements 44.

  As shown in FIGS. 3 to 8, the lens cover 18 is formed in a ring shape and is made of a light-transmitting material (for example, a transparent acrylic resin). As shown in FIG. 8, the lens cover 18 is attached to one surface of the reflective cover 14 with screws 56 so as to cover the inner peripheral portions of the plurality of substrates 42. At this time, the lens cover 18 covers the plurality of first light emitting elements 44 of each of the plurality of substrates 42 and does not cover the plurality of second light emitting elements 46 of each of the plurality of substrates 42.

  The lens cover 18 has a plurality of lens portions 18 a corresponding to the plurality of first light emitting elements 44. Light from each of the plurality of first light emitting elements 44 passes through the corresponding lens portion 18a. At this time, each of the plurality of lens portions 18a expands the light distribution angle of the transmitted light.

[1-8. Cosmetic cover]
Next, the decorative cover 20 will be described with reference to FIGS. The decorative cover 20 is a cover for covering the reflective cover 14 and the instrument body 8 from the side to make up.

  As shown in FIGS. 5 to 7, the decorative cover 20 is formed in a ring shape. Specifically, the decorative cover 20 extends in a trumpet shape from one end (the end on the floor surface side) to the other end (the end on the ceiling 4 side). It is arranged so as to cover from the side. The decorative cover 20 is made of, for example, white polystyrene resin.

  As shown in FIGS. 6 and 7, a ring-shaped support portion 20 a that extends while curving toward the radially inner side of the decorative cover 20 and the other end portion of the decorative cover 20 is formed at one end portion of the decorative cover 20. ing. The support portion 20a supports an inner peripheral surface of a light guide portion 22b (described later) of the light guide plate 22.

  On the inner surface of the decorative cover 20, a ring-shaped protrusion 20 b extending over the entire circumference of the decorative cover 20 is formed. The protrusion 20 b is in contact with the flange portion 14 b of the reflective cover 14. Thereby, the decorative cover 20 is positioned with respect to the reflective cover 14.

[1-9. Light guide plate]
Next, the light guide plate 22 will be described with reference to FIGS. 1 to 7 and 10. FIG. 10 is a diagram showing the light guide plate 22 extracted from the embodiment. FIG. 10A is a perspective view showing the light guide plate 22, and FIG. 10B is a cross-sectional perspective view taken along line XX of FIG.

  The light guide plate 22 is an optical member for guiding incident light from each of the plurality of second light emitting elements 46 in a predetermined direction (direction toward the space 6). As shown in FIGS. 1 to 7 and FIG. 10A, the overall shape of the light guide plate 22 is formed in a ring shape (doughnut shape) having a substantially circular opening 22a at the center. The light guide plate 22 includes a light guide part 22b, an incident part 22c, an emission part 22d, and a plurality of branch light guide parts 22e. The light guide plate 22 is formed of a light-transmitting material (for example, a transparent acrylic resin).

  A prism shape 60 (an example of a fine structure portion) in which a number of fine conical concave prisms are arranged in the circumferential direction is formed on a part or all of the surface forming the emission portion 22d. Note that the shape of the prism is not limited to a concave shape, and may be a convex shape. That is, the prism shape 60 is formed of a prism surface through which light is transmitted and reflected by at least one plane or curved surface having a concave shape or a convex shape. Further, the shape of the prism is not limited to the conical shape in any of the concave shape and the convex shape, and may be, for example, a quadrangular pyramid shape, or a conical shape, a quadrangular pyramid shape or a ring having an asymmetric concave portion. The shape etc. may have a shape in which a part of the slope has functions of transmission and reflection. In addition, the prism shape 60 may be a printed matter formed by a method such as screen printing using an ink containing fine particles having a scattering property or a pigment, particularly when the prism is formed in a convex shape. . Alternatively, the prism shape 60 may be a rough surface formed by embossing or the like. As for the arrangement of the prisms, they may be arranged at regular intervals along a specific direction or may be arranged randomly. In addition, it is not necessary to arrange the prisms on all of the surfaces forming the emission part 22d, and the prisms may be arranged on only a part of the surfaces.

  As shown in FIGS. 6 and 7, the light guide portion 22b is formed between the incident portion 22c and the emission portion 22d, and from one end portion (end portion on the ceiling 4 side) to the other end portion (end on the floor surface side). Part). That is, the above-described opening 22a is formed on the radially inner side of the light guide 22b, and the plurality of first light emitting elements 44 and the lens cover 18 are arranged at positions facing the opening 22a. The light guide 22b guides light from one end to the other end. The inner peripheral surface (concave surface) of the light guide portion 22 b is supported by the support portion 20 a of the decorative cover 20. The outer peripheral surface (convex surface) of the light guide portion 22b is covered with a reflection portion 24a (described later) of the reflection member 24. That is, the light guide part 22 b is sandwiched between the support part 20 a of the decorative cover 20 and the reflection part 24 a of the reflection member 24.

  The incident portion 22c is formed in a ring shape over the entire circumference of one end portion of the light guide portion 22b, and is approximately from the one end portion of the light guide portion 22b to the central axis 58 (Z-axis direction) of the opening portion 22a. It extends in parallel. The incident portion 22 c is disposed at a position facing and close to the plurality of second light emitting elements 46.

  The emitting portion 22d extends in a ring shape outward from the entire circumference of the other end portion of the light guide portion 22b in the radial direction of the light guide plate 22. The emitting portion 22d protrudes outward in the radial direction of the light guide plate 22 from one end portion of the decorative cover 20, and is arranged in a substantially horizontal posture (that is, in a posture substantially parallel to the ceiling 4). The one surface (floor surface) of the emitting portion 22d is a surface from which light is emitted. As shown in FIG. 7, the prism shape 60 described above is formed on the other side surface (the surface on the ceiling 4 side) of the emitting portion 22d.

  As shown in FIGS. 5 to 7, the plurality of branched light guide portions 22 e branch and extend from the incident portion 22 c to the radially inner side of the light guide plate 22 (that is, a direction different from the direction in which the light guide portion 22 b extends). Yes. The plurality of branch light guide portions 22e are arranged at intervals in the circumferential direction of the incident portion 22c corresponding to the plurality of substrates 42. Each of the plurality of branch light guides 22e has a screw 48 (see FIG. 8) in a predetermined region of the corresponding substrate 42 (a region between the plurality of first light emitting elements 44 and the plurality of second light emitting elements 46). ).

  Here, the characteristic configuration of the light guide plate 22 will be described in more detail with reference to FIGS. 11 is a cross-sectional view taken along line XI-XI in FIG. FIG. 12 is an enlarged cross-sectional perspective view showing the incident portion 22c of the light guide plate 22 according to the embodiment. For convenience of explanation, in FIG. 11, hatching representing a cross section is not shown.

  As shown in FIGS. 11 and 12, the incident portion 22c has a prism structure 62 that converts part of the diverging light from the second light emitting element 46 into light parallel to a predetermined direction. In the cross section (cross section shown in FIGS. 11 and 12) in which the light guide 22b is cut along a virtual plane including the central axis 58 of the opening 22a, the central axis 64 of the prism structure 62 is in the vertical direction (Z-axis direction). On the other hand, it extends substantially in parallel.

  As shown in FIG. 12, the prism structure 62 is formed asymmetrically with respect to the central axis 64 in the cross section. That is, in the cross section, the curvature of the convex surface 62 a on one side of the prism axis 62 of the prism structure 62 is different from the curvature of the convex surface 62 b on the other side of the prism axis 62 of the prism structure 62.

  As shown in FIG. 11, the light guide part 22 b includes an inclined part 66 and a curved part 68.

  As shown in FIGS. 11 and 12, the inclined portion 66 extends from the incident portion 22c while being inclined in a direction approaching the emission portion 22d with respect to the central axis 64 of the prism structure 62. Note that the inclination angle θ of the inclined portion 66 with respect to the central axis 64 is, for example, about 10 °.

  As shown in FIG. 11, the bending portion 68 extends while being curved from the inclined portion 66 to the emitting portion 22d. On the outer peripheral surface (convex surface) of the curved portion 68, the first reflection surface 70, the second reflection surface 72, and the third reflection for guiding the light incident on the incident portion 22c while reflecting the light toward the emitting portion 22d. A surface 74 is formed.

  The first reflecting surface 70 forms a parabola having a focal point F in the cross section. The first reflecting surface 70 is formed over a range from the boundary position between the curved portion 68 and the inclined portion 66 to a position closer to the incident portion 22c than the focal point F.

  The second reflecting surface 72 forms a curve such as a parabola or an arc in the cross section. The second reflecting surface 72 is formed over a range from the boundary position between the curved portion 68 and the emitting portion 22d to a position closer to the emitting portion 22d than the focal point F. That is, the second reflecting surface 72 is disposed on the side closer to the emitting portion 22d than the first reflecting surface 70 in the cross section.

  More specifically, the second reflecting surface 72 is disposed at a position intersecting with an imaginary straight line (indicated by a one-dot chain line in FIG. 11) passing through the first reflecting surface 70 and the focal point F in the cross section. . In other words, in the cross section, the second reflecting surface 72 has an imaginary straight line 76 passing through one end on the incident portion 22c side of the first reflecting surface 70 and the focal point F, and the emitting portion 22d side of the first reflecting surface 70. Is formed in a region sandwiched by an imaginary straight line 78 passing through the other end of the lens and the focal point F.

  As shown in FIGS. 10A and 10B, a rough surface 80 is formed on the convex surface side of the second reflecting surface 72 by an uneven processing. At this time, the rough surface 80 may be formed over the entire area of the second reflecting surface 72, or may be formed only on a part of the second reflecting surface 72. Further, the rough surface 80 may be formed by subjecting the second reflecting surface 72 to a random roughening process such as a graining process or a sandblasting process instead of the uneven process described above.

  The third reflecting surface 74 forms a curve such as a parabola or an arc in the cross section. The third reflecting surface 74 is formed between the first reflecting surface 70 and the second reflecting surface 72. In addition, the 1st reflective surface 70, the 2nd reflective surface 72, and the 3rd reflective surface 74 form the smooth curve as a whole in the said cross section.

  As shown in FIG. 11, a concave portion 82 is formed between the light guide portion 22b and the emission portion 22d on the inner peripheral surface side of the light guide portion 22b. The concave portion 82 is formed in a ring shape over the entire circumference of the other end portion of the light guide portion 22b. The thickness (size in the Z-axis direction) in the region where the recess 82 of the emission part 22d is formed is smaller than the thickness in the region where the recess 82 of the emission part 22d is not formed.

[1-10. Reflective member]
Next, the reflecting member 24 will be described with reference to FIGS. The reflection member 24 is a member for reflecting the light guided inside the light guide portion 22 b of the light guide plate 22.

  As shown in FIGS. 4-7, the reflection member 24 is formed in the ring shape. Specifically, the reflecting member 24 has a reflecting portion 24a and a pressing portion 24b. The reflecting member 24 is made of, for example, polycarbonate resin.

  The reflecting portion 24a extends in a trumpet shape from one end (the end on the ceiling 4 side) to the other end (the end on the floor side). A reflecting surface is formed on the concave side of the reflecting portion 24a. The concave surface side of the reflecting portion 24 a covers the outer peripheral surface of the light guide portion 22 b of the light guide plate 22.

  The pressing portion 24b extends in a ring shape from the entire circumference of one end of the reflecting portion 24a to the radially inner side of the reflecting member 24. The pressing portion 24b is attached to a predetermined region of each of the plurality of substrates 42 with screws 48 together with the plurality of branch light guide portions 22e. As a result, as shown in FIGS. 6 and 7, the tip of the pressing portion 24 b presses the outer peripheral portion of the lens cover 18 toward the plurality of substrates 42.

[1-11. Diffusion cover]
Next, the diffusion cover 26 will be described with reference to FIGS. 1 and 3 to 7. The diffusion cover 26 is a cover for diffusing light from each of the plurality of first light emitting elements 44.

  As shown in FIGS. 1 and 3 to 7, the diffusion cover 26 is detachably attached to the reflection member 24 and is disposed so as to cover the opening 22 a of the light guide plate 22. As shown in FIG. 3, the lens cover 18 is exposed from the opening 22 a of the light guide plate 22 by removing the diffusion cover 26 from the reflecting member 24. As shown in FIGS. 6 and 7, the diffusion cover 26 includes a diffusion portion 26a and an attachment portion 26b.

  The diffusion part 26 a is formed in a disk shape and is disposed so as to cover the opening 22 a of the light guide plate 22. The diffusion portion 26a is formed of a light-transmitting material (for example, milky white acrylic resin).

  The attachment portion 26b extends in a trumpet shape from the entire circumference of the outer peripheral portion of the diffusion portion 26a in the axial direction (Z-axis direction) of the diffusion portion 26a. The attachment portion 26b is detachably attached to the convex surface side of the reflection portion 24a of the reflection member 24.

[1-12. Lighting method]
Next, the lighting method by the lighting fixture 2 mentioned above is demonstrated, referring FIG.6, FIG7 and FIG.11. By supplying DC power from the power supply unit 12 to the light emitting module 16, each of the plurality of first light emitting elements 44 and the plurality of second light emitting elements 46 emits light.

  As shown in FIGS. 6 and 7, the light from each of the plurality of first light emitting elements 44 passes through the corresponding lens portion 18 a of the lens cover 18 and then passes through the opening 22 a of the light guide plate 22 to diffuse the cover 26. Is incident on. The light incident on the diffusion cover 26 is emitted from the diffusion cover 26 while being diffused, and then irradiates the space 6. That is, the light from each of the plurality of first light emitting elements 44 directly irradiates the space 6 without entering the light guide plate 22.

  As shown in FIG. 7, a part of the light from each of the plurality of first light emitting elements 44 is reflected by the reflecting member 24 and the like and then reflected by one surface of the reflecting cover 14. The multiple reflected light enters the diffusion cover 26 as described above. Thereby, the light extraction efficiency can be increased.

  On the other hand, as shown in FIGS. 7 and 11, light (diverged light) from each of the plurality of second light emitting elements 46 is incident on the incident portion 22 c of the light guide plate 22 by the prism structure 62. A part is converted into light parallel to the light guide direction. The parallel light incident on the incident portion 22c is reflected by the first reflecting surface 70, the second reflecting surface 72, and the third reflecting surface 74 inside the light guide portion 22b (and also the reflecting portion of the reflecting member 24). The light is guided from the incident portion 22c toward the emission portion 22d (while being reflected by 24a).

  As shown in FIG. 11, the light guided to the inside of the light guide portion 22b first enters the concave surface side of the first reflecting surface 70 at an incident angle larger than the critical angle, whereby the first reflecting surface. Total reflection occurs at 70. At this time, it is preferable that the first reflecting surface 70 is disposed in a region where most of the parallel light incident on the incident portion 22c can be totally reflected. The light totally reflected by the first reflecting surface 70 travels while converging inside the light guide 22b toward the focal point F, and after being condensed at the focal point F, enters the second reflecting surface 72 while diverging. To do.

  The light from the first reflecting surface 70 is totally reflected by the second reflecting surface 72 by being incident on the concave surface side of the second reflecting surface 72 at an incident angle larger than the critical angle. The light totally reflected by the second reflecting surface 72 is guided to the inside of the emitting portion 22d and reflected by the prism shape 60 formed on the other surface of the emitting portion 22d, so that the light on one side of the emitting portion 22d is reflected. Emits from the surface.

  At this time, the light from the second light emitting element 46 is converted into parallel light by the prism structure 62, and then condensed at the focal point F due to the parabolic shape characteristic of the first reflecting surface 70. Therefore, if the convex side of the second reflecting surface 72 is a smooth surface, the light totally reflected by the second reflecting surface 72 is guided to the inside of the emitting portion 22d as the condensed light beam. A striped pattern resulting from the density distribution of the condensed light flux is generated on one surface of the emitting portion 22d. On the other hand, in the present embodiment, since the rough surface 80 is formed on the second reflecting surface 72, the light totally reflected by the second reflecting surface 72 is diffused inside the emitting portion 22d. Led to. Thereby, it can suppress that the striped pattern mentioned above generate | occur | produces on the surface of the one side of the output part 22d.

  A part of the light guided to the inside of the light guide unit 22b is reflected on the concave surface side of the third reflecting surface 74 and then guided to the inside of the emitting unit 22d.

  Further, a part of the light (returned light) reflected many times by the prism shape 60 tends to return to the light guide portion 22b. However, as shown in FIG. 11, the return light is reflected by the recess 82 formed in the light guide plate 22, and is guided again to the inside of the emission part 22 d without returning to the light guide part 22 b.

  As shown in FIG. 11, out of the light incident on the incident portion 22 c of the light guide plate 22, a part of the light that has not been converted into parallel light by the prism structure 62 is incident on the branch light guide portion 22 e. At this time, by forming the pressing portion 24b of the reflection member 24 with, for example, a transparent resin, the light incident on the branch light guide portion 22e is transmitted through the pressing portion 24b and enters the diffusion cover 26. Alternatively, the light incident on the branch light guide 22e can be made incident on the diffusion cover 26 by omitting the pressing portion 24b of the reflecting member 24. Further, when the second reflecting surface 72 is subjected to a roughening process such as embossing, a part of the guided light can be incident on the diffusion cover 26, and the diffusion cover 26 emits light uniformly during light emission. Therefore, the appearance quality as illumination can be improved.

  As described above, the space 6 can be directly illuminated by the light from the diffusion cover 26, and the light can be illuminated from the space 6 by the light from the emitting portion 22 d of the light guide plate 22. Thereby, the space 6 directly under the lighting fixture 2 is relatively brightly directly illuminated by the light from the diffusion cover 26, so that it is possible to ensure the illuminance necessary for reading or manual work, for example. On the other hand, the space 6 around the luminaire 2 is light-guided and illuminated by the light from the light emitting portion 22d of the light guide plate 22 as if it is indirect illumination, so that a feeling of relaxation can be produced.

  Note that in this embodiment, the case where the plurality of first light-emitting elements 44 and the plurality of second light-emitting elements 46 are turned on has been described. However, for example, the plurality of first light-emitting elements depending on the indoor atmosphere. Only 44 may be lit, or only a plurality of second light emitting elements 46 may be lit.

[2. effect]
The lighting fixture 2 of this Embodiment is provided with the 2nd light emitting element 46 and the light-guide plate 22 for guide | inducing the light from the 2nd light emitting element 46 to a predetermined direction. The light guide plate 22 is formed between the incident portion 22c where the light from the second light emitting element 46 is incident, the emission portion 22d where the light incident on the incident portion 22c is emitted, and the incident portion 22c and the emission portion 22d. The first light-reflecting portion 22b, which extends while curving from the incident portion 22c to the emitting portion 22d, and guides the light incident on the incident portion 22c while reflecting it toward the emitting portion 22d. And a light guide 22b having two reflecting surfaces 72 on the outer peripheral surface. The first reflecting surface 70 forms a parabola having a focal point F in a cross section when the light guide 22b is cut along a virtual plane. The second reflecting surface 72 is arranged on the side closer to the emitting portion 22d than the first reflecting surface 70 in the cross section, and at a position intersecting with an imaginary straight line passing through the first reflecting surface 70 and the focal point F. Has been placed.

  According to this, since the first reflecting surface 70 forms a parabola having a focal point F in the cross section, the light reflected by the first reflecting surface 70 among the light guided into the light guide portion 22b is The light guide unit 22b advances while converging toward the focal point F, and after being focused at the focal point F, the light enters the second reflecting surface 72 while diverging. Further, the light reflected by the second reflecting surface 72 is guided to the inside of the emitting part 22d and is emitted toward the space 6 from the emitting part 22d. Thereby, since the light reflected by the 1st reflective surface 70 can be efficiently entered in the 2nd reflective surface 72, generation | occurrence | production of the propagation loss of the light in the light guide part 22b can be suppressed, 2nd The utilization efficiency of light from the light emitting element 46 can be increased.

  Further, the incident portion 22c has a prism structure 62 that converts part of the light from the second light emitting element 46 into light parallel to the light guide direction.

  According to this, since the light from the second light emitting element 46 can be efficiently reflected by the first reflecting surface 70, the utilization efficiency of the light from the second light emitting element 46 can be further enhanced. .

  Further, the prism structure 62 is formed asymmetrically with respect to the central axis 64 of the prism structure 62 in cross section.

  According to this, since the optical axis of the parallel light beam from the prism structure 62 is inclined with respect to the central axis 64 of the prism structure 62, the parallel light beam from the prism structure 62 is larger than the critical angle on the first reflecting surface 70. It can be made incident at an incident angle. As a result, the light incident on the first reflecting surface 70 is totally reflected by the first reflecting surface 70, so that the light use efficiency from the second light emitting element 46 can be further enhanced.

  Further, the light guide part 22b extends from the incident part 22c while being inclined from the incident part 22c in a direction approaching the emission part 22d with respect to the central axis 64 of the prism structure 62, and from the inclined part 66 to the emission part 22d. And a curved portion 68 in which a first reflecting surface 70 and a second reflecting surface 72 are formed.

  According to this, the parallel light flux from the prism structure 62 can be efficiently guided into the inclined portion 66.

  Furthermore, a rough surface 80 is formed on at least a part of the second reflecting surface 72.

  According to this, the light reflected by the second reflecting surface 72 is guided to the inside of the emitting portion 22 d while being diffused by the rough surface 80. Thereby, it is possible to suppress the occurrence of a striped pattern due to the density distribution of the collected light flux in the emitting portion 22d.

  Further, the second reflecting surface 72 forms a curve in the cross section.

  According to this, the light reflected by the 2nd reflective surface 72 can be efficiently guide | induced to the inside of the output part 22d.

  Further, on the inner peripheral surface side of the light guide portion 22b, a recess 82 is formed between the light guide portion 22b and the emission portion 22d.

  According to this, the return light which is going to travel in the direction returning from the emitting part 22d to the light guiding part 22b is reflected again by the concave part 82, and is guided again to the inside of the emitting part 22d without returning to the light guiding part 22b. It is burned. As a result, the utilization efficiency of light from the second light emitting element 46 can be further enhanced.

  Furthermore, the light guide plate 22 has a branched light guide part 22e that branches and extends in a direction different from the light guide part 22b from the incident part 22c.

  According to this, the light which was not guide | induced to the inside of the light guide part 22b among the light which injected into the incident part 22c can be entered into the branch light guide part 22e. As a result, the light incident on the branch light guide part 22e can be contributed to the direct illumination of the space 6, and the utilization efficiency of the light from the second light emitting element 46 can be further enhanced.

  Furthermore, a prism shape 60 for emitting light from the emitting portion 22d is formed on at least a part of the emitting portion 22d.

  According to this, the light guided to the inside of the emission part 22d is emitted from the emission part 22d by being reflected by the prism shape 60. As a result, light can be efficiently emitted from the emission part 22d.

  Furthermore, the light guide plate 22 is formed in a ring shape having an opening 22a. The light guide part 22b has an opening part 22a and spreads in a trumpet shape from the incident part 22c toward the emission part 22d. The incident part 22c extends substantially parallel to the central axis 58 of the opening 22a from one end of the light guide part 22b. The emitting portion 22d extends from the other end portion of the light guide portion 22b to the outside in the radial direction of the light guide portion 22b. The virtual plane is a plane including the central axis 58 of the opening 22a.

  According to this, the luminaire 2 can be applied as, for example, a circular ceiling light by forming the light guide plate 22 in a ring shape.

(Modification)
Next, a light guide plate 22A according to a modification of the embodiment will be described with reference to FIG. FIG. 13 is an enlarged perspective view showing a part of a light guide plate 22A according to a modification of the embodiment.

  As shown in FIG. 13, a rough surface 80A is formed on the second reflecting surface 72A of the light guide plate 22A according to the modification by a prism shape. Even with such a configuration, as described in the above embodiment, it is possible to suppress the occurrence of a striped pattern caused by the density distribution of the light beam condensed on the emitting portion 22d.

  Instead of the prism shape described above, the rough surface 80A may be formed by forming, for example, a microlens array shape on the second reflecting surface 72A.

(Other variations)
As described above, the present invention has been described based on the embodiment and the modification. However, the present invention is not limited to the embodiment and the modification.

  In the above embodiment and the like, the lighting fixture 2 is a ceiling light, but is not limited to this, and may be a chandelier, a pendant light, a bracket light, a bathroom light, a kitchen light, or the like. Or it is good also considering the lighting fixture 2 as a backlight etc. which are mounted, for example in a liquid crystal display device.

  In the above-described embodiment and the like, the prism structure is the prism structure 62 that converts the divergent light from the second light emitting element 46 into parallel light. However, the present invention is not limited to this. For example, from the second light emitting element 46 It is good also as a condensing lens structure which converts the divergent light into convergent light.

  Moreover, in the said embodiment etc., although the light-guide plate 22 (22A) was formed in the ring shape, it is not limited to this, For example, you may form in a rectangular shape.

  Moreover, in the said embodiment etc., although the 2nd reflective surface 72 formed the curve in the said cross section, it is not limited to this, The 2nd reflective surface 72 forms a straight line in the said cross section, for example. It may be.

  In the above-described embodiment and the like, each mounting structure of the first light emitting element 44 and the second light emitting element 46 is an SMD structure, but the present invention is not limited to this. For example, a COB in which an LED chip is directly mounted on the substrate 42. (Chip On Board) structure may be sufficient. In this case, the plurality of LED chips mounted on the substrate 42 may be collectively sealed by the sealing member, or may be individually sealed. The sealing member may contain a wavelength conversion material such as the yellow phosphor described above.

  Moreover, in the said embodiment etc., although LED was illustrated as the 1st light emitting element 44 and the 2nd light emitting element 46, it is not limited to this, For example, semiconductor light emitting elements, such as a semiconductor laser, organic EL (Electro Luminescence) Alternatively, other solid light emitting elements such as inorganic EL may be used.

  In addition, it is realized by arbitrarily combining the components and functions in each embodiment without departing from the scope of the present invention, or the form obtained by making various modifications conceived by those skilled in the art to the above-described embodiment. This form is also included in the present invention.

2 lighting fixtures 22 and 22A light guide plate 22a opening 22b light guide 22c entrance 22d exit 22e branch light guide 46 second light emitting element (light emitting element)
58, 64 Center axis 60 Prism shape (fine structure)
62 Prism structure 66 Inclined portion 68 Curved portion 70 First reflecting surface 72, 72A Second reflecting surface 76, 78 Virtual straight line 80, 80A Rough surface 82 Concave portion F Focus

Claims (10)

A light emitting element;
A light guide plate for guiding light from the light emitting element in a predetermined direction,
The light guide plate is
An incident part into which light from the light emitting element is incident;
An emission part from which light incident on the incident part is emitted; and
A light guide unit formed between the incident unit and the output unit, extending from the incident unit to the output unit while curving, and reflecting light incident on the incident unit toward the output unit. And a light guide unit having a first reflection surface and a second reflection surface on the outer peripheral surface for guiding,
The first reflecting surface forms a parabola having a focal point in a cross section when the light guide section is cut along a virtual plane;
The second reflecting surface is disposed on the side closer to the emitting part than the first reflecting surface in the cross section, and intersects a virtual straight line passing through the first reflecting surface and the focal point. Located in the luminaire. The lighting apparatus according to claim 1, wherein the incident portion has a prism structure that converts light from the light emitting element into parallel light or convergent light. The lighting fixture according to claim 2, wherein the prism structure is formed asymmetrically with respect to a central axis of the prism structure in the cross section. The light guide is
An inclined part extending from the incident part while being inclined in a direction approaching the emission part with respect to a central axis of the prism structure;
The lighting apparatus according to claim 3, further comprising a curved portion that extends while being curved from the inclined portion to the emitting portion, and in which the first reflective surface and the second reflective surface are formed. The lighting fixture according to any one of claims 1 to 4, wherein a rough surface is formed on at least a part of the second reflecting surface. The lighting apparatus according to claim 1, wherein the second reflecting surface forms a curve in the cross section. The lighting fixture of any one of Claims 1-6 in which the recessed part is formed between the said light guide part and the said output part in the inner peripheral surface side of the said light guide part. The lighting apparatus according to any one of claims 1 to 7, wherein the light guide plate further includes a branched light guide portion that branches and extends from the incident portion in a direction different from the light guide portion. The lighting fixture according to any one of claims 1 to 8, wherein a fine structure portion for emitting light from the emission portion is formed on at least a part of the emission portion. The light guide plate is formed in a ring shape having an opening,
The light guide portion has the opening, and spreads in a trumpet shape from the incident portion toward the emission portion,
The incident part extends substantially parallel to the central axis of the opening from one end of the light guide part,
The emitting part extends from the other end of the light guide part to the radially outer side of the light guide part,
The lighting fixture according to claim 1, wherein the virtual plane is a plane including the central axis of the opening.

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