WO2019008829A1

WO2019008829A1 - Lighting device

Info

Publication number: WO2019008829A1
Application number: PCT/JP2018/009016
Authority: WO
Inventors: 孝夫牛山
Original assignee: 興和株式会社
Priority date: 2017-07-05
Filing date: 2018-03-08
Publication date: 2019-01-10
Also published as: JP6998376B2; JPWO2019008829A1

Abstract

In the present invention, light from a point light-source (LED element (10)) is drawn into a light guide body (20). The light guide body (20) includes: a straight light-guide section (21) that extends along a central axis; a curved light-guide section (22) that switches the path of light towards the outer diameter direction; and an expanding and opening light-guide section (23) that has a flat panel shape and that expands further in the outer diameter direction. The LED element (10) is disposed at a position facing a light incidence surface (24) which is the staring-end surface of the straight light-guide section (21). From a light emission surface (26) formed in the expanding and opening light-guide section (23), light is emitted towards an outer-circumferential space (1) of the straight light-guide section (21).

Description

Lighting device

The present invention relates to a lighting device suitable as a lighting stand disposed on a desk or a floor.

The applicant has previously proposed an innovative lighting device that makes use of the characteristics of a point light source such as an LED light source and a light guide (see Patent Document 1: International Publication No. 2014/080771). Such a luminaire is suitable as a ceiling-embedded luminaire which is mainly embedded in the ceiling of a room. That is, the illumination device disclosed in Patent Document 1 has a configuration in which light of a point light source is taken in from the upper end face of the light guide, and light for illumination is directly emitted downward from the lower surface of the light guide. Therefore, when used as a ceiling-embedded lighting fixture, the wiring for power supply can be drawn in and connected from the ceiling to the point light source provided opposite to the upper end face of the light guide, so the wiring management Is easy.

International Publication No. 2014/080771

However, in order to use the lighting device disclosed in Patent Document 1 as a lighting stand disposed on a desk or a floor surface, the problem of complicating the structure of the wiring arrangement for supplying power to the point light source, etc. I had it. That is, in order to use the lighting device as a lighting stand, for example, the wiring for power supply to the point light source is routed through the hollow portion of the support pole, so the upper end of the support pole is located on the light guide. The end face side needs to be rolled in, which complicates the structure. Moreover, in order to hold the heavy apparatus main body including the point light source and the light guide with the support pole from the upper side, it is necessary to secure sufficient strength in the support structure.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a lighting device suitable as a lighting stand disposed on a desk or a floor surface.

In order to achieve the above object, the present invention has a configuration in which light from a point light source is taken into the inside from the light incident surface of a light guide and emitted from a light emission surface formed in a part of the light guide. Lighting device, and
The light guide has a light incident surface formed downward at the center lower position, and a curved light guiding portion for guiding the light of a point light source taken from below the light incident surface in the direction of the outer diameter, and the curved light guide And a flat-plate-like spread light guiding portion that continuously spreads outward from the end of the light portion, and
A reflective member is provided around the periphery of the light incident surface to the curved light guide, for diffusely reflecting the light transmitted without being totally reflected in the light guide among the light taken into the light guide. And

A light diffusing surface is formed on the upper surface of the spread light guiding portion, and a lower surface facing the upper surface is used as a light emitting surface, and light is emitted from the light emitting surface.

As in this configuration, by disposing the light incident surface to the bottom center position of the light guide, the wiring for power supply to the light incident surface and the oppositely disposed point light source, it Torimawasu from below It is possible to easily realize the application to a lighting stand disposed on a desk or a floor surface.

The present invention may further include a base unit for holding a point light source, and the base unit may be disposed to face the light incident surface formed at the lower central position of the light guide.
With this configuration, it is possible to easily route the power supply wiring to the point light source through the base unit disposed opposite to the central lower position of the light guide, and it can be used on a desk or a floor surface, etc. The application to the arranged lighting stand can be realized more easily.

Here, the present invention preferably includes a support unit, supports the base unit from below by the support unit, and incorporates a wiring for supplying power to the point light source in the support unit. Thereby, the illumination stand can be easily configured.

The reflecting member includes an outer peripheral surface in contact surface of the lightguide, the light transmitted without being totally reflected in the light guide out of the captured light to the light guide member to the inside of the light guide and with constituting a light leakage prevention means for diffusively reflecting at least a portion of the outer peripheral surface, it is preferable to configure the peripheral irradiation means for reflecting to the surrounding part of the light emitted from the light exit surface.

Since the leakage of the light taken into the light guide by the reflection member is prevented, the attenuation of the light can be suppressed and the light can be efficiently emitted from the light emission surface. The light emitted from the light emitting surface of the light guide illuminates brightly the position facing the light emitting surface and the periphery thereof. Furthermore, a part of the light emitted from the light emitting surface is incident on the outer peripheral surface of the reflection member which constitutes the peripheral illumination means, and is diffusely reflected on the outer peripheral surface to illuminate the periphery. Since the amount of light incident on the outer peripheral surface of the reflecting member is smaller than the amount of light irradiated to the position facing the light emitting surface and the periphery thereof, the periphery is dimly illuminated, and a unique illumination effect is generated. You can get it.

Furthermore, a protective cover may be attached to a portion facing the light emitting surface of the light guide and the outer peripheral surface of the reflecting member.
The protective cover transmits much of the light emitted from the light emitting surface, and reflects a part of the light toward the outer peripheral surface of the reflection member constituting the peripheral illumination means by the inner surface of the protective cover.

This configuration can prevent the light emitting surface of the light guide and the outer peripheral surface of the reflecting member from being scratched or soiled. Moreover, the inner surface of the protective cover reflects a part of the light emitted from the light emission surface toward the outer peripheral surface (peripheral irradiation means) of the reflective member, whereby the outer peripheral surface of the reflective member is reflected from the light output surface. Light is incident at an angle different from that of direct incident light. Thus, light can be reflected at various angles from the outer peripheral surface of the reflective member to illuminate the periphery of a wide angle range.

Further, according to the present invention, a light leakage prevention portion for reflecting the light diffused by the light diffusion surface to the inside of the spread light guide portion is provided on the upper side of the light diffusion surface formed in the spread light guide portion of the light guide. It is preferable to set it as follows. With this configuration, the light diffused by the spread light guide can be efficiently emitted from the light emission surface.

Furthermore, the present invention is expanded light guiding portion of the lightguide, a light diffusing surface may be an inclined surface converging to the outer circumferential direction with respect to the light exit surface (hereinafter referred to as "wedge-shaped cross section light guide section") . By setting the light diffusion surface to be an inclined surface as described above, it is possible to efficiently cause most of the light guided from the curved light guide to be incident on the light diffusion surface.

As described above, according to the present invention, by disposing the light incident surface to the bottom center position of the light guide, the wiring for power supply to the light incident surface and the oppositely disposed point source It becomes possible to handle from below, and the application to a lighting stand disposed on a desk or a floor surface can be easily realized.

FIG. 1 is a front cross-sectional view showing the configuration of a lighting device according to an embodiment of the present invention. FIG. 2A is an exploded perspective view of each component of the lighting device according to the embodiment of the present invention. FIG. 2B is a perspective view showing a circuit board on which point light sources are arranged. FIG. 3 is a front cross-sectional view for explaining the lighting operation by the lighting device according to the embodiment of the present invention. FIG. 4 is a perspective view showing a configuration example of a lighting stand by the lighting device according to the embodiment of the present invention. FIG. 5 is a front cross-sectional view showing the configuration of a lighting device according to another embodiment of the present invention. FIG. 6 is an exploded perspective view of each component constituting a lighting device according to another embodiment of the present invention. FIG. 7A is a front cross-sectional view showing the configuration of the illumination device according to the third embodiment of the present invention. FIG. 7B is a front cross-sectional view showing a part of the light guide in an enlarged manner. FIG. 8A and FIG. 8B are exploded perspective views of each part which comprises the illuminating device based on 3rd Embodiment of this invention. FIG. 9: is front sectional drawing which shows the illumination effect by the illuminating device which concerns on 3rd Embodiment of this invention.

10: Point light source (LED element),
20: light guide, 21: straight light guide, 22: curved light guide, 23: spread light guide, 23a: outer peripheral side of spread light guide, 23 ': cross section wedge light guide, 23a': cross section Outer peripheral side surface of ridge-shaped light guide 24: light incident surface 25: light diffusion surface 26: light exit surface 27: inner light guide
30: reflective member, 31: first reflective member, 32: second reflective member, 31a cylindrical wall, 33: light guide facing surface, 34: outer peripheral reflective surface 40: circuit board, 41: wiring cord, 42: wiring pattern ,
50: Substrate, 51: Wiring hole,
60: Protective cover,
70: Reflective sheet (light leakage prevention part),
80: Top cover,
90: first light diffusion transmission cover 91: second light diffusion transmission cover 100: mounting table 101: support pole

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First Embodiment
FIG. 1 is a front cross-sectional view showing the configuration of the illumination device according to the first embodiment of the present invention, and FIG. 2A is an exploded perspective view of each component constituting the device.
In addition, in FIG. 1, the hatching which shows a cut surface is abbreviate | omitted by the light guide 20 mentioned later and the protective cover 60 (the same is said of FIG. 3, FIG. 5, FIG. 7 A and FIG. 9). In FIG. 7B, hatching is performed to clarify the cross section facing in the center direction of the light reflecting surface.

Illumination apparatus according to this embodiment takes in light from the point light source 10 from the light incident surface 24 of the light guide 20 therein, and emitted from the light emitting surface 26 formed on a part of the light guide member 20 It is a basic structure to illuminate. A reflective member 30 is provided around the light incident surface 24 of the light guide 20 from the light incident surface 24 to a certain range, and light transmitted through the light guide 20 is transmitted without being totally reflected in the light guide 20. The light is diffused and reflected to prevent leakage of the light to the outside.

For the point light source 10, for example, an LED (light emitting diode) element can be used. In the present embodiment, an LED element is used as the point light source 10, and the same reference numerals are given to proceed with the following description.
As shown in FIG. 2B, a plurality of LED elements 10 are arranged and soldered in the circumferential direction on the upper surface of the circuit board 40. The arrangement of the LED elements 10 corresponds to the shape of the light incident surface 24 of the light guide 20 described later, and each LED element 10 is positioned to face the light incident surface 24 of the light guide 20 .

The conductor of the wiring cord 41 is attached to the circuit board 40 by means such as soldering. Each LED element 10 is electrically connected to the conductor of the wiring cord 41 via the wiring pattern 42 formed on the circuit board 40 in advance.
The wiring cord 41 supplies the power transmitted from the power supply circuit (not shown) to each of the LED elements 10. Each of the LED elements 10 emits light with the supplied power.

The light guide 20 repeats the total reflection internally with minimal attenuation with respect to the light taken in from the light incident surface 24, and the light incident on the light diffusion surface 25 is diffusely reflected to the light emitting surface 26. And an optical member having a function of emitting the light from the light emitting surface 26 to the outside. The light guide 20 can be formed of, for example, a transparent resin material such as an acrylic resin.

In the present embodiment, the light guide 20 is formed in a shape as shown in FIG. 2A, and as shown in FIG. 1, the respective components of the rectilinear light guide 21, the curved light guide 22 and the spread light guide 23 are These parts are integrally molded.
As shown in FIG. 2A, the rectilinear light guiding portion 21 is formed in a cylindrical shape extending along the central axis O, and its starting end face (lower end face in the figure) is a light incident surface 24 for taking in light. . The light incident surface 24 is located at the lower center of the light guide 20. In the present embodiment, the light incident surface 24 is formed in an annular shape, and as described above, the plurality of LED elements 10 are disposed to face the light incident surface 24.

The curved light guide portion 22 is a portion which curves from the end of the rectilinear light guide portion 21 extending along the central axis O to change the path of light in the outer diameter direction. The spread light guide portion 23 is a portion that further spreads in the outer diameter direction from the end of the curved light guide portion 22. The spread light guide portion 23 is formed in a flat plate shape having the same thickness, and the outer peripheral edge is formed in a circular shape.

Furthermore, the upper flat surface of the spread light guide portion 23 forms a light diffusion surface 25. The light diffusion surface 25 is a surface for diffusing and reflecting the light guided to the spread light guiding portion 23. The light diffusion surface 25 is, for example, a paint that processes the upper surface of the spread light guide portion 23 into a rough surface or a fine uneven surface by a processing method such as embossing, sand blasting, silk printing, or irregularly reflects light. It can form by apply | coating to.
In the present embodiment, the light diffusion surface 25 is formed in the same manner on the outer peripheral side 23 a of the spread light guide 23 as well. That is, in FIGS. 1 and 3, the region indicated by a thick line forms the light diffusion surface 25.

The lower flat surface of the spread light guide portion 23 forms a light emitting surface 26. The light emitting surface 26 faces the upper surface on which the light diffusing surface 25 is formed as described above, and the light diffused and reflected by the light diffusing surface 25 is emitted from the light emitting surface 26 to the outside. (See a in FIG. 3). The external space from which light is emitted in this way is a space existing on the outer periphery of the rectilinear light guide 21 as shown in FIG. 1, and light is emitted mainly downward through this outer peripheral space. Ru.

Next, as shown in FIG. 1, the reflection member 30 is provided around the area extending from the rectilinear light guide 21 (specifically, the peripheral portion of the light incident surface 24) to the curved light guide 22, and in this region The light transmitted without being totally reflected in the two light guide portions is diffused and reflected to the inside of the light guide 20 to prevent the light from leaking to the outside. In the present embodiment, as shown in FIG. 1 and FIG. 2A, the reflecting member 30 is configured by the first reflecting member 31 and the second reflecting member 32. The first reflection member 31 is fitted below the light guide 20, and the second reflection member 32 is fitted above the light guide 20.

The reflecting member 30 is made of, for example, a resin material that does not transmit light, and the light guide surface of the light guide facing surface (a light guide facing surface 33) facing the outer surface of the light guide 20 The light leak preventing means is configured to diffuse and reflect the light transmitted without totally reflecting inside the body 20 to the inside of the light guide 20. The light guide facing surface 33 is disposed on the surface of the light guide 20 via an air layer, and the light emitted from the inside of the light guide 20 without being totally reflected is inside the light guide 20. Any arrangement that can reflect light can be used. Such light guide facing surface 33 is preferably formed on the diffuse reflection surface for diffusing reflected almost all of the light absorption of the light is incident very small, but is not limited thereto.

Further, in the reflection member 30 (in the present embodiment, the first reflection member 31), the outer peripheral surface (the outer peripheral reflection surface 34) exposed to the outer peripheral space 1 of the rectilinear light guide 21 is the light emitted from the light emission surface 26. The peripheral illumination means is configured to reflect part of the light to the periphery. Part of the light emitted from the light emitting surface 26 is incident on the outer peripheral reflecting surface 34, and is reflected by the outer peripheral reflecting surface 34 to illuminate the periphery thereof (see symbol b in FIG. 3).

Here, the brightness for illuminating the surroundings can be arbitrarily adjusted in accordance with the degree of reflection and absorption of light at the outer peripheral reflection surface 34. For example, when the outer peripheral reflection surface 34 is formed as a diffuse reflection surface, absorption of incident light can be suppressed and diffuse reflection can be performed, so that the surroundings can be brightly illuminated. However, even in such a case, the amount of light incident on the outer peripheral reflection surface 34 is smaller than the amount of light irradiated to the position facing the light emission surface 26 and the periphery thereof, so the periphery is slightly illuminated. It is possible to
In addition, when the outer peripheral reflection surface 34 is formed in a color that absorbs a part of incident light, such as matte black, the amount of reflected light in the direction of the user's eyes decreases, and a lighting effect with more reduced glare can be obtained. it can.

Further, in the present embodiment, as shown in FIG. 1, the leading edge of the reflection member 30 is disposed so as to surround the LED element 10 disposed on the circuit board 40. Thereby, almost all the light emitted from the LED element 10 can be taken into the inside from the light incident surface 24 of the light guide 20 without leaking to the outside.

As shown in FIG. 1 and FIG. 2A, the circuit board 40 to which the LED element 10 is soldered is held on the upper surface of the base 50. By forming the base 50 as a metal part, it can also serve as a heat sink for dissipating heat generated by the LED element. The circuit board 40 and the base 50 constitute a base unit for holding the LED element 10. The substrate 50 is arranged opposite to the light incident surface 24 formed on the bottom center position of the light guide body 20, circuit board 40, the components of the light guide body 20 and the reflecting member 30 is supported at the lower center position . Furthermore, wiring holes 51 are formed in the base 50 along the central axis O. The wiring cord 41 for supplying power to the LED element 10 can be routed downward through the wiring hole 51.

Further, the outer peripheral surface opposite to the site of the light emitting surface 26 and the reflecting member 30 of the light guide 20, at a periphery space 1 of the straight light guide section 21, protective cover 60 are mounted. The protective cover 60 can be made of a transparent or translucent material that has the function of transmitting most of the incident light and reflecting part of it. The protective cover 60 can prevent the light emitting surface 26 of the light guide 20 and the outer peripheral surface of the reflecting member 30 from being scratched or soiled.

The protective cover 60 transmits most of the light emitted from the light emission surface 26 toward the outer peripheral space 1 of the rectilinear light guide 21. Further, the protective cover 60 has a function of a part of the light emitted toward the outer peripheral space 1 of the light emitting surface 26 from the straight light guide section 21, it is reflected toward the outer peripheral reflecting surface 34 of the reflecting member 30 ing. The protective cover 60, reflection toward the outer circumferential reflection surface 34 of the member 30 by reflecting the light, the light is incident at an angle different from that of the light entering directly from the light exit surface 26 on the outer circumferential reflection surface 34 of the reflecting member 30 (See the symbol c in FIG. 3). Thus, light can be reflected at various angles from the outer peripheral surface of the reflective member 30 to illuminate the periphery of a wide angle range.

In addition, a reflective sheet 70 is disposed on the upper side of the light diffusion surface 25 formed in the spread light guide portion 23 of the light guide 20. The reflection sheet 70 constitutes a light leakage prevention unit that reflects the light diffused and transmitted by the light diffusion surface 25 to the inside of the spread light guiding unit 23. That is, the surface of the reflective sheet 70 facing the light diffusion surface 25 is finished to be a diffuse reflection surface that does not transmit or absorb light, and almost all the light incident from the inside of the light guide 20 is It has a function to reflect inside. Note that, instead of the reflective sheet 70, a paint of a color that transmits and does not absorb light but reflects substantially all of the incident light is applied to the upper side of the light diffusion surface 25 to form a light leakage prevention portion May be An upper cover 80 is mounted on the upper side of the reflective sheet 70.

The lighting apparatus having the above-described configuration can be assembled in the following procedure.
The conductors of the LED element 10 and the wiring cord 41 are soldered to the circuit board 40 in advance. The lower end edge of the protective cover 60 is disposed in advance and combined with the upper end edge of the base 50. Then, in a state where the wiring cord 41 passes through the wiring hole 51, the circuit board 40 is disposed on the upper surface of the base 50.
Subsequently, these components are assembled in the order of the first reflection member 31, the light guide 20, and the second reflection member 32 on the top of the circuit board 40, and the reflection sheet 70 is disposed on the upper surface thereof.
Thereafter, the upper surface opening of the device is covered with the upper cover 80, and the lower end peripheral portion of the upper cover 80 is fitted into the upper end edge of the protective cover 60 to complete the lighting device shown in FIG.

The base 50 and the circuit board 40 may be bonded with an adhesive or fixed with a fastener such as a screw. The protective cover 60 and the base 50 may be bonded in advance with an adhesive. Between the protective cover 60 and the upper cover 80 may be locking claw and previously formed the engagement portion, and configured to hold a state fitted with their engagement. Also, the protective cover 60 and the upper cover 80 may be bonded with an adhesive or fixed with a fastener such as a screw.

The respective components of the first reflection member 31, the light guide 20 and the second reflection member 32 are held between the base 50 and the upper cover 80 without rattling and supported by the base 50. In addition, preferably, an elastic buffer member may be disposed between the circuit board 40 and the base 50, or between the reflective sheet 70 and the upper cover 80 to prevent rattling more appropriately. .

Next, with reference to FIG. 3, the lighting operation of the lighting apparatus according to the present embodiment will be described.
The light emitted from the LED element 10 is taken into the inside from the light incident surface 24 of the light guide 20. As for the light taken into the light guide 20, the light whose incident angle on each surface exceeds the critical angle repeats total reflection and travels from the rectilinear light guide 21 to the curved light guide 22 and spreads the light However, the light emitted without being totally reflected at the portion 23 is diffused and reflected by the reflection member 30 and returned to the inside of the light guide, thereby advancing from the rectilinear light guiding portion 21 to the curved light guiding portion 22 and expanding The light guide portion 23 is reached. As described above, since the light taken into the light guide 20 is prevented from leaking to the outside by the reflecting member 30, attenuation of the light can be suppressed and the light can be efficiently guided to the spread light guide 23.

Most of the light guided to the spread light guide portion 23 is diffused by the light diffusion surface 25 and emitted from the facing light emitting surface 26 to the outer peripheral space 1 of the rectilinear light guide portion 21. Of the light diffused by the light diffusion surface 25, the diffuse transmission light is diffusely reflected by the reflection sheet 70 and returned to the inside of the light guide 20. Since the light returned in this manner is also emitted from the light emission surface 26, the light diffused by the spread light guiding portion 23 can be efficiently emitted from the light emission surface 26. The light guided to the spread light guide portion 23 is light which is incident on the light diffusion surface 25 and diffusely reflected or diffusely transmitted, or is totally reflected again by the light emitting surface 26 and further spread at the spread light guide portion 23. The light to be guided and the light whose incident angle at the light exit surface 26 is less than the critical angle may exit from the light exit surface 26 as it is.
Most of the light emitted from the light emission surface 26 of the light guide 20 passes through the outer peripheral space 1 of the rectilinear light guide portion 21, passes through the protective cover 60, and a position facing the light emission surface 26 and the periphery thereof In the present embodiment, the lower area of the lighting device is illuminated brightly.

Furthermore, part of the light emitted from the light emitting surface 26 is incident on the outer circumferential reflection surface 34 of the reflecting member 30, at its periphery (in this embodiment is reflected in the outer peripheral reflecting surface 34, the side of the illumination device Illuminate the area). Since the amount of light incident on the outer peripheral reflecting surface 34 of the reflecting member 30 is smaller than the amount of light irradiated to the position facing the light emitting surface 26 and the periphery thereof, the periphery is slightly illuminated and unique A lighting effect can be obtained.

Moreover, the protective cover 60 reflects part of the light emitted from the light emission surface 26 toward the outer peripheral reflection surface 34 of the reflection member 30. Therefore, light is incident on the outer peripheral reflection surface 34 of the reflection member 30 at an angle different from that of light directly incident from the light emission surface 26. Thus, light can be reflected at various angles from the outer peripheral reflection surface 34 of the reflection member 30 to illuminate the periphery of a wide angle range.

The illuminating device which concerns on this embodiment becomes a preferable structure for the application to an illumination stand.
FIG. 4 shows a configuration example in which the lighting device according to the embodiment is applied to a lighting stand. For example, as shown in the drawing, the illumination stand can be configured by extending the support pole 101 obliquely upward from the mounting table 100 and connecting the upper end of the support pole 101 to the base 50. The support pole 101 may be configured to be rotatable at a predetermined angle with a line extending vertically from the fulcrum as a fulcrum, with the connecting portion with the mounting table 100 as a fulcrum.

The wiring cord 41 for supplying power to the LED element 10 can be routed from the wiring hole 51 of the base 50 through the inside of the hollow portion of the support pole 101. Therefore, application to a lighting stand disposed on a desk or a floor can be easily realized.
The mounting table 100 and the support pole 101 form a support unit that supports the circuit board 40 and the base 50 (base unit) from below and incorporates the wiring cord 41 for supplying power to the LED element 10.

Second Embodiment
Next, a lighting apparatus according to a second embodiment of the present invention will be described with reference to the drawings.
FIG. 5 is a front cross-sectional view showing the configuration of a lighting device according to a second embodiment of the present invention, and FIG. 6 is an exploded perspective view of each component constituting the device. In the illumination device according to the second embodiment shown in these figures, the same parts as or corresponding parts to the illumination device according to the first embodiment shown in FIGS. 1 to 3 are given the same reference numerals. The detailed description of the part is omitted.

In the illumination device shown in FIG. 5 and FIG. 6, the rectilinear light guide portion 21 of the light guide 20 is formed in a cylindrical shape, and the light incident surface 24 is formed on the front end face thereof. Then, at a position facing the light incident surface 24, one or a small number of LED elements 10 are arranged, it is constituted to capture light emitted from the LED element 10 from the light incident surface 24 into the interior of the light guide 20 .

Since the illumination device having such a configuration can reduce the dimension in the outer diameter direction of the light guide 20 as compared with the illumination device according to the first embodiment (see FIGS. 1 to 3), miniaturization is achieved. There are advantages above.

Third Embodiment
Next, a lighting apparatus according to a third embodiment of the present invention will be described with reference to the drawings.
FIG. 7A is a front cross-sectional view showing the configuration of the illumination device according to the third embodiment of the present invention. 8A and 8B are exploded perspective views of parts constituting the apparatus, FIG. 8A is an exploded perspective view of the parts viewed obliquely from below, and FIG. 8B is an exploded perspective view of the parts viewed obliquely from above FIG. FIG. 9: is front sectional drawing which shows the illumination effect by the illuminating device which concerns on 3rd Embodiment of this invention.

In the lighting apparatus according to the third embodiment shown in these figures, the same parts as or parts corresponding to the lighting apparatus according to the first embodiment shown in FIGS. 1 to 3 are given the same reference numerals. It is The detailed description of the configuration and the operation common to the first embodiment will be partially omitted.

Similarly to the illumination device according to the first embodiment described above, the illumination device according to the present embodiment also takes in the light from the point light source 10 from the light incident surface 24 of the light guide 20 into the light guide 20 and The basic structure is to emit light from the light emission surface 26 formed in a part of
A reflective member 30 is provided around the light incident surface 24 of the light guide 20 from the light incident surface 24 to a certain range, and light transmitted through the light guide 20 is transmitted without being totally reflected in the light guide 20. The light is diffused and reflected to prevent leakage of the light to the outside.

Also in the present embodiment, as shown in FIG. 8B, a plurality of LED elements 10 as point light sources are arranged and soldered in the circumferential direction on the upper surface of the circuit board 40. These LED elements 10 are supplied with power through the wiring cords 41 to emit light and emit light.

Placement of the LED element 10 is located as an arrangement corresponding to the shape of the light incident surface 24 of the light guide 20 to be described later, each LED element 10 is positioned to face the light incident surface 24 of the light guide 20 .

In the present embodiment, as shown in FIG. 7A, the light guide 20 includes the respective portions of the curved light guide 22 and the cross-sectional ridge-like light guide 23 ′, which are integrally formed. A surface (lower end surface in the figure) is a light incident surface 24 for receiving light. The light incident surface 24 is located at the lower center of the light guide 20. Also in the present embodiment, the light incident surface 24 is formed in an annular shape, and as described above, the plurality of LED elements 10 are disposed to face the light incident surface 24.

The curved light guide portion 22 is a portion that bends from the peripheral portion of the light incident surface 24 to change the path of light in the outer diameter direction. The cross-sectional ridge-shaped light guide 23 ′ is a portion that further extends in the outer diameter direction from the end of the curved light guide 22. As the name suggests, the cross-sectional ridge-shaped light guide 23 'is formed to have a wedge-shaped cross section, and the thickness is reduced toward the outer periphery, and the outer peripheral edge is formed in a circular shape.

Also in the present embodiment, as in the first embodiment, the upper flat surface of the cross-sectional ridge-shaped light guide 23 ′ forms the light diffusion surface 25. On the other hand, the lower plane of the cross-sectional ridge-shaped light guide 23 ′ forms a light emitting surface 26. Then, the light diffused and reflected by the light diffusion surface 25 is emitted from the light emission surface 26 toward the outside (see a symbol a in FIG. 9).

Here, as shown in FIG. 7B, the cross-sectional wedge-shaped light guide portion 23 ′ of the light guide 20 has an inclination angle at which the light diffusion surface 25 (upper surface) converges in the outer peripheral direction with respect to the light emission surface 26 (lower surface). It is an inclined surface of θ. That is, the light diffusion surface 25 (upper surface) approaches the light emission surface 26 (lower surface) in the outer peripheral direction. By setting the light diffusion surface 25 to be an inclined surface as described above, it is possible to make the light guided from the curved light guide 22 more incident on the light diffusion surface 25. Even the light guided from the curved light guide 22 and traveling parallel to the light emitting surface 26 is diffused because the light diffusing surface 25 is an inclined surface (in the first and second embodiments, the light emitting surface 26 Light traveling in parallel with the light will leak light).
Therefore, light can be efficiently incident on the light diffusion surface 25 and diffused by the light diffusion surface 25 to be emitted from the light emission surface 26, the amount of light emitted from the light emission surface 26 is increased, and improvement in illuminance is realized. can do.

The reflection member 30 is comprised by the 1st reflection member 31 and the 2nd reflection member 32, as shown to FIG. 7A, FIG. 8A and FIG. 8B. The first reflection member 31 is fitted below the light guide 20, and the second reflection member 32 is fitted above the light guide 20.

In the present embodiment, the first reflection member 31 is disposed along the lower surface of the curved light guide portion 22 of the light guide 20. In addition, the second reflection member 32 is disposed along the upper surface from the curved light guide portion 22 of the light guide 20 to the spread light guide portion 23.

Here, in the first reflection member 31, a light guide surface of the light guide 20 facing the inner surface of the curved light guide portion 22 (light guide facing surface 33) is a light guide among the light taken into the light guide 20. The light leak preventing means is configured to diffuse and reflect the light transmitted without totally reflecting inside the body 20 to the inside of the light guide 20. Similarly, in the second reflection member 32, a light guide surface of the light guide 20 facing the outer surface of the curved light guide 22 (light guide facing surface 33) is a light guide among the light taken into the light guide 20. The light leak preventing means is configured to diffuse and reflect the light transmitted without totally reflecting inside the body 20 to the inside of the light guide 20.
The light guide facing surface 33 is installed on the surface of the light guide 20 via an air layer, and light emitted from the inside of the light guide 20 without being totally reflected is introduced into the inside of the light guide 20. It can be reflected.

In the present embodiment, a disk-shaped reflection sheet 70 is disposed between the second reflection member 32 and the outer surface of the cross-sectional ridge-shaped light guide 23 ′ in the light guide 20. Therefore, the area where the reflective sheet 70 is disposed can efficiently reflect the light downward, and the illuminance of the light emitted from the emission surface 26 can be improved.

The reflection sheet 70 constitutes a light leakage prevention unit that reflects the light diffused by the light diffusion surface 25 to the inside of the cross-sectional ridged light guide 23 ′. That is, the surface of the reflective sheet 70 facing the light diffusion surface 25 is finished to be a diffuse reflection surface that does not transmit or absorb light, and almost all the light incident from the inside of the light guide 20 is It has a function to reflect inside. Note that, instead of the reflective sheet 70, a paint of a color that transmits and does not absorb light but reflects substantially all of the incident light is applied to the upper side of the light diffusion surface 25 to form a light leakage prevention portion May be

The first reflection member 31 has a cylindrical wall 31a whose outermost part extends in parallel with the central axis, and the outer peripheral surface (the outer peripheral reflection surface 34) of the cylindrical wall 31a is emitted from the light emission surface 26. The ambient illumination means is configured to reflect part of the light to the ambient. A part of the light emitted from the light emitting surface 26 is incident on the outer peripheral reflecting surface 34 and is reflected by the outer peripheral reflecting surface 34 to illuminate the periphery thereof (see symbol b in FIG. 9).

Further, in the present embodiment, the central portion of the upper cover 80 is open, and the first light diffuse transmission cover 90 is fitted into the opening. Furthermore, the second light diffusion transmission cover 91 is fitted in the central opening of the light guide 20 as well. Each of the light diffusion transmission covers is formed of a synthetic resin or the like having a function of diffusing and transmitting incident light.
In the present embodiment, the inner light guide portion 27 is continuously formed on the central lower portion inner circumferential side (inner circumferential side than the light incident surface 24) of the light guide 20.

Then, the light emitted from the LED element 10 mounted on the circuit board 40 is reflected in the inner light guide portion 27 of the light guide 20 and is incident on the second light diffusion transmission cover 91. The second light diffusion transmission cover 91 diffuses and transmits incident light. Thus, the diffused light transmitted through the second light diffusing and transmitting cover 91 subsequently enters the first light diffusing and transmitting cover 90, is also diffused here, and is emitted from the upper surface of the cover 90 to the outside (reference numeral in FIG. 9) d)).
The lighting apparatus according to the present embodiment has a function to lightly illuminate the external space above the upper cover 80 with the kind of diffused light with eyes, with such an action.

The inner light guide 27 also has the following effects. Since white LEDs are combined with blue light LEDs and phosphors that emit yellow light that is excited by blue light to emit its complementary color, yellow light may be noticeable in the periphery. In that case, ambient light that did not enter the light incident surface 24 appeared as yellow leaked light, but by providing the inner light guide 27, white light that is not only ambient light will be mixed So yellow is less noticeable. In the third embodiment, in particular, this light illuminates the upper side through the second light diffusion transmission cover 91 and the first light diffusion transmission cover 90, which is an important effect.

The present invention is not limited to the above-described embodiments, and it goes without saying that various modifications and applications can be made without departing from the scope of the invention described in the claims. is there.

Claims

An illumination device having a configuration in which light from a point light source is taken in from the light incident surface of a light guide and emitted from a light emission surface formed in a part of the light guide,
The light guide has the light incident surface formed downward at a central lower position, and a curved light guide which guides the light of the point light source taken from below the light incident surface by changing the path in the outer diameter direction; And a flat-plate-like spread light guide which continuously spreads outward from the end of the curved light guide.
Diffusely reflects light transmitted without being totally reflected inside the light guide among the light taken into the inside of the light guide around the periphery of the light incident surface to the curved light guide. A reflective member is provided,
An illumination apparatus comprising: a light diffusion surface formed on an upper surface of the spread light guide portion; a lower surface facing the upper surface being the light emission surface; and light is emitted from the light emission surface.
A base unit for holding the point light source is provided, and the base unit is disposed to be opposed to the light incident surface formed at the center lower position of the light guide. Lighting equipment.
The lighting device according to claim 2, further comprising: a support unit supporting the base unit from below and incorporating a wire for supplying power to the point light source.
The reflecting member has a surface in contact with the outer peripheral surface of the light guide, of the light taken into the inside of the light guide, the light transmitted without being totally reflected inside the light guide is A light leakage preventing means for diffusely reflecting the inside is constituted, and at least a part of the outer peripheral surface constitutes a peripheral irradiation means for reflecting a part of the light emitted from the light emitting surface to the surroundings. The lighting device according to any one of claims 1 to 3.
A protective cover is attached to a portion facing the light emitting surface of the light guide and the outer peripheral surface of the reflecting member,
The protective cover is configured to transmit most of the light emitted from the light emission surface, and to reflect a part of the light toward the outer peripheral surface of the reflection member that constitutes the peripheral irradiation means. The lighting device according to claim 4.
A light leakage prevention portion for reflecting the light diffused by the light diffusion surface to the inside of the spread light guide portion is provided above the light diffusion surface formed in the spread light guide portion of the light guide. The lighting device according to any one of claims 1 to 5, wherein
Expanding the light guide portion of the light guide body, the light diffusing surface, any one of claims 1 to 6, characterized in that forming the inclined surfaces converging to the outer circumferential direction with respect to the light emitting surface A lighting device according to item 5.