JP2020136193A - Illuminating device - Google Patents

Abstract

To provide an illuminating device that can be made thinner, and can improve uniformity of light to be emitted.SOLUTION: An illuminating device 100 comprises: a light source part 20; and a light guide plate 160 for emitting light emitted from the light source part 20 and incident from an end surface (first incident surface 162a), from a front surface 166a directed frontward. The light guide plate 160 comprises an incident part 161 forming the end surface (first incident surface 162a), a front surface part 166 forming the front surface 166a, and an outwardly convex curved part 165 for changing a path of light between the incident part 161 and the front surface part 166. A light extraction part 180 having a concave shape or a convex shape is provided in an outside surface of the curved part 165.SELECTED DRAWING: Figure 7

Description

The present invention relates to a lighting device including a light guide plate.

As one of the lighting devices for illuminating a space, a lighting device mounted on a ceiling is known. For example, the lighting device disclosed in Patent Document 1 is arranged with a fixture main body mounted on a ceiling surface, an LED (Light Emitting Diode) light emitting portion provided on the fixture main body, and an incident end surface facing the LED light emitting portion. It includes a light guide plate and a pair of holding members that are supported by the instrument body and hold the light guide plate in the thickness direction.

Japanese Unexamined Patent Publication No. 2015-204162

In the lighting device disclosed in Patent Document 1, since light is incident on the end surface of the flat plate-shaped light guide plate, the circuit board on which a plurality of LED chips, which are LED light emitting portions, are arranged, is the light emitting surface of the light guide plate. It is arranged in a posture orthogonal to. Simply put, the circuit board is arranged in a vertical position with respect to the flat plate-shaped light guide plate. That is, in the fixture body of the lighting device, the LED light emitting unit is arranged in a state where the circuit board is erected. This is a factor that hinders the thinning of the lighting device used as a ceiling light, for example. In order to avoid such a problem, for example, the circuit board of the LED light emitting portion is laid flat on the instrument main body, and the end face of the light guide plate and the light are arranged so that the end face of the light guide plate faces the LED light emitting portion. It is conceivable to provide a curved portion between the light emitting surface and the front surface. As a result, the light guide plate can emit the light incident on the end face from the horizontally placed LED light emitting portion as illumination light through the wide front surface (spreading in the horizontal direction) directed forward.

However, since the curved portion of the light guide plate is a portion where light is not easily emitted, for example, when the lighting device arranged on the ceiling is looked up from below, the curved portion is observed as a dark portion in the light emitting region of the lighting device. May be done.

The present invention has been made by the inventor of the present application paying new attention to the above problems, and an object of the present invention is to provide a lighting device which can be made thinner and can improve the uniformity of emitted light. To do.

The lighting device according to one aspect of the present invention includes a light source unit and a light guide plate that emits light emitted from the light source unit and incident from the end face from the front surface, and the light guide plate forms the end face. It has an incident portion, a front portion forming the front surface, and an outwardly convex curved portion that changes the course of light between the incident portion and the front surface portion, and is concave on the outer surface of the curved portion. A light extraction portion having a shape or a convex shape is provided.

According to the present invention, it is possible to provide a lighting device that can be made thinner and can improve the uniformity of emitted light.

It is a perspective view which shows the appearance of the lighting apparatus which concerns on embodiment. It is an exploded perspective view of the lighting apparatus which concerns on embodiment. It is sectional drawing which shows the structural outline of the lighting apparatus which concerns on embodiment. It is an enlarged sectional view for demonstrating the details of the incident part and the front part of the light guide plate which concerns on embodiment. It is an exploded perspective view which shows the arrangement example of the light diffusing part in the light guide plate which concerns on embodiment. It is a top view which shows the arrangement example of the light extraction part in the light guide plate which concerns on embodiment. It is sectional drawing which shows an example of the shape of the light extraction part which concerns on embodiment. It is sectional drawing which shows another example of the shape of the light extraction part which concerns on embodiment.

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

It should be noted that each figure is a schematic view and is not necessarily exactly illustrated. Further, in each figure, substantially the same configuration is designated by the same reference numerals, and duplicate description may be omitted or simplified.

Further, in the following embodiments and claims, expressions indicating relative directions or postures such as parallel and orthogonal may be used, but these expressions are strictly speaking the directions or postures. Including cases where it is not. For example, the fact that two directions are orthogonal not only means that the angles formed by the two directions are exactly 90 °, but also that they are substantially orthogonal, that is, a difference of, for example, about several percent. It also means to include. Further, "forward" indicates the main light emission direction of the lighting device, and in the present embodiment, it is the direction on the Z-axis plus side. For example, when the lighting device is arranged on the ceiling so as to illuminate the floor surface in the room, the front side of the lighting device is the direction toward the floor surface side.

(Embodiment)
[1. Basic configuration of lighting equipment]
First, the basic configuration of the lighting device 100 according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing the appearance of the lighting device 100 according to the embodiment. FIG. 2 is an exploded perspective view of the lighting device 100 according to the embodiment. FIG. 3 is a cross-sectional view showing an outline of the configuration of the lighting device 100 according to the embodiment. Specifically, FIG. 3 simply illustrates a cross section of the illuminating device 100 in the YZ plane passing through lines III-III of FIG. Further, in FIG. 3, as for the light emitting element 21, only one light emitting element 21 arranged at the position of the line III-III is shown on the side surface.

As shown in FIG. 1, the illuminating device 100 of the present embodiment is a illuminating device mounted on a ceiling, for example, a ceiling light. The lower direction (Z-axis minus direction) in FIG. 1 is the direction in which the ceiling exists. That is, in FIGS. 1 and the following figures (excluding FIG. 6), the lighting device 100 is shown in an upside-down posture as opposed to normal use.

The lighting device 100 according to the present embodiment includes a main body 110, a light source 20 attached to the main body 110, a light source 160 arranged in front of the light source 20, a light source 20, and a light guide 160. A diffusion cover 140 for covering is provided.

The light source unit 20 has a substrate 25 and a plurality of light emitting elements 21 arranged on the front surface of the substrate 25. The light guide plate 160 has an incident portion 161 that forms an end surface on which light is incident from the light source unit 20, and a front surface portion 166 that forms a front surface 166a that emits light incident from the incident portion 161. The diffusion cover 140 covers the light source unit 20 and the light guide plate 160, and diffuses the light emitted from the light guide plate 160 and emits it to the outside.

In the present embodiment, the circuit accommodating portion 101 is arranged on the back side of the main body portion 110, and the circuit board 50 is arranged on the circuit accommodating portion 101. The circuit board 50 is a board having a power supply circuit and a control circuit composed of a plurality of circuit components 60, and supplies power to the light source unit 20 via electric wires (not shown), and turns on, off, dimming, and toning. To control. A cylinder 70 in which a nightlight and a light receiving portion are arranged inside is arranged in a part of the circuit board 50. The light receiving unit is a device that receives infrared light for controlling the lighting device 100.

In the central portion of the circuit accommodating portion 101, a support portion 102 that supports an attachment 30 for attaching the lighting device 100 to a socket provided on the ceiling is arranged. The circuit accommodating portion 101 is fixed to the back surface of the main body portion 110 with a plurality of screws (not shown).

An opening 113 of the main body 110 and an opening 168 of the light guide plate 160 are arranged in front of the support 102. Therefore, the user can access the attachment 30 through the opening 168 and the opening 113 by removing the diffusion cover 140 detachably attached to the main body 110. This allows the user to attach and detach the luminaire 100 into and out of a socket located on the ceiling.

An opening 114 of the main body 110 is arranged in front of the cylinder 70, and the light receiving unit can receive infrared light transmitted from the remote controller without being blocked by the main body 110.

[2. Body]
As shown in FIG. 1, the main body 110 is formed in a disk shape, and is a member manufactured by using a sheet metal such as an aluminum plate or a steel plate. For example, a white paint having high light reflectance is applied or a reflective metal material is vapor-deposited on the surface of the main body 110 on the side where the light source portion 20 and the like are arranged.

A circular opening 113 is formed in the central portion of the main body 110, and a substantially cylindrical support portion 102 is exposed from the opening 113. Further, on the side of the opening 113, an opening 114 into which the tip of the tubular body 70 arranged on the back surface side of the main body 110 is inserted is formed. A reflection surface portion 112 is formed around the opening 113 so as to contact or approach the back surface of the light guide plate 160 and re-enter the light leaked from the light guide plate 160 into the light guide plate 160.

An outer peripheral portion 115 recessed behind the reflective surface portion 112 is formed around the reflective surface portion 112, and the light source portion 20 is fixed to the outer peripheral portion 115 by, for example, a plurality of screws (not shown). Further, a plurality of attachment members 111a for detachably attaching the diffusion cover 140 to the main body 110 are arranged on the outer peripheral portion 115.

As described above, the circuit accommodating portion 101 is fixed to the back surface of the main body portion 110. The circuit accommodating portion 101 is a member manufactured by using a sheet metal such as an aluminum plate or a steel plate like the main body portion 110. In the present embodiment, the outer shell of the lighting device 100 is formed by the diffusion cover 140, the main body 110, and the circuit accommodating 101.

[3. Light source]
As shown in FIGS. 1 to 3, the light source unit 20 includes a substrate 25 and a plurality of light emitting elements 21 arranged on the substrate 25. In the present embodiment, the substrate 25 is configured by electrically connecting four separate substrates that are arranged in an annular shape, but for convenience of explanation, these four substrates are connected. Are treated as one substrate 25.

The substrate 25 has an annular outer shape when viewed from the front, and the plurality of light emitting elements 21 are arranged in an annular shape along the shape of the substrate 25. The substrate 25 is a printed circuit board provided with a conductor pattern (metal wiring). As such a substrate 25, for example, a glass composite substrate such as a CEM3 (Composite epixy material-3) substrate, a resin substrate, a ceramic substrate, a paper phenol substrate, a metal base substrate, or the like is adopted.

In the present embodiment, each of the plurality of light emitting elements 21 is, for example, an LED element in which an LED chip is packaged. That is, the mounting structure of the light source unit 20 is an SMD (Surface Mount Device) structure in which an LED element in which an LED chip is packaged is mounted on a substrate 25. The plurality of light emitting elements 21 included in the light source unit 20 include, for example, two types of light emitting elements 21 having different color temperatures. For example, even if the plurality of light emitting elements 21 included in the light source unit 20 are composed of a group of light emitting elements 21 having a high color temperature (first group) and a group of light emitting elements 21 having a low color temperature (second group). Good. In this case, by adjusting the brightness of each of the light emitting element 21 of the first group and the light emitting element 21 of the second group, that is, by controlling the dimming, the color of the light emitted by the light source unit 20 is adjusted, that is, toning. Control may be performed.

In the light source unit 20 configured in this way, since the substrate 25 is arranged in a state of being in contact with the outer peripheral portion 115 of the main body portion 110, the heat generated by the plurality of light emitting elements 21 is efficiently externalized by the main body portion 110. Is dissipated to.

[4. Diffusion cover]
The diffusion cover 140 is a member that covers the light source unit 20 and the light guide plate 160, and is made of a translucent resin. The diffusion cover 140 is, for example, milky white and can be produced by injection molding a resin material in which light diffusion particles are dispersed. The diffusion cover 140 can diffuse the light from each light emitting element 21 and emit it to the outside. Further, the diffusion cover 140 may have a light diffusion function by forming a milky white light diffusion layer or a plurality of light diffusion dots or minute irregularities (textures) on the inner surface or the outer surface. As described above, the diffusion cover 140 is detachably attached to the attachment member 111a of the main body 110.

In the present embodiment, the diffusion cover 140 has a feature that it is circular when viewed from the front (hereinafter, also referred to as a plan view) and the width (thickness) in the Z-axis direction is relatively thin. are doing.

Specifically, in the present embodiment, the light emitted by each of the plurality of light emitting elements 21 does not reach the diffusion cover 140 directly or through the lenses arranged in each light emitting element 21. The light from the surface light source reaches the diffusion cover 140 via the light guide plate 160. That is, the light emitted by each of the plurality of light emitting elements 21 reaches the diffusion cover 140 as light from a pseudo surface light source by the light guide plate 160. Therefore, in FIG. 3, when the maximum distance between the front surface portion 166 of the light guide plate 160 and the diffusion cover 140 is Ha, and the distance between the light source unit 20 and the front surface portion 166 of the light guide plate 160 is Hb, for example. , Ha <Hb. That is, by reducing the distance between the inner surface of the diffusion cover 140 and the front surface portion 166 of the light guide plate 160, the width of the diffusion cover 140 in the Z-axis direction can be reduced. Even in this case, since the light from the pseudo surface light source formed on the light guide plate 160 is mainly incident on the diffusion cover 140, it is formed on each of the plurality of light emitting elements 21 via the diffusion cover 140. It is substantially prevented that the bright spots to be seen are visible.

[5. Light guide plate]
The light guide plate 160 is an optical member for guiding the light from each of the plurality of light emitting elements 21 of the light source unit 20 to the space in front of the lighting device 100 (direction on the plus side of the Z axis), and provides translucency. It is made of a material (for example, a transparent acrylic resin). As shown in FIGS. 2 and 3, the light guide plate 160 has an incident portion 161 into which the light emitted by the light source unit 20 is incident, and a front surface portion 166 in which the light incident from the incident portion 161 is emitted. .. The light guide plate 160 further has an outwardly convex curved portion 165 that diverts the path of light between the incident portion 161 and the front surface portion 166. The incident unit 161 has a first incident surface 162a, which is an end surface on which the light emitted by the light source unit 20 is incident. The front surface portion 166 is a planar portion orthogonal to the light emitting direction (Z-axis plus side direction) from the light source unit 20. The front surface portion 166 has a front surface 166a which is a light emitting surface and a back surface 166b which is a surface opposite to the front surface 166a. The incident portion 161 is formed in an annular shape surrounding the front surface portion 166 when the light guide plate 160 is viewed from the front surface 166a side, and a plurality of light emitting elements 21 are arranged side by side at positions facing the incident portion 161. There is.

Here, in the toning control of the lighting device 100, for example, when emitting warm-colored illumination light, only the light emitting element 21 of the group (second group) of the light emitting element 21 having a substantially low color temperature is lit. Conditions can also occur. Even in this case, if the light emitting elements 21 of the second group are arranged at substantially equal intervals in the row of the light emitting elements 21 arranged in an annular shape, the illumination light emitted from the light guide plate 160 is the first. Luminance unevenness due to lighting of only two groups of light emitting elements 21 is suppressed. That is, according to the pseudo surface light source formed by the light guide plate 160, the brightness unevenness due to the scattered light emitting elements 21 as the light source is unlikely to occur, and the light emitting elements 21 each of which is a point light source are bright spots. Hard to be observed as. Further, according to the light guide plate 160, since a surface light source can be artificially created with a relatively small number of light emitting elements 21, the manufacturing cost can be suppressed or the manufacturing process can be simplified.

The light guide plate 160 configured in this way will be further described with reference to FIGS. 4 to 8 in addition to FIGS. 1 to 3. First, the basic configuration of the light guide plate 160 will be specifically described with reference to FIGS. 4 and 5. FIG. 4 is an enlarged cross-sectional view for explaining the details of the incident portion 161 and the front surface portion 166 of the light guide plate 160 according to the embodiment. The position of the cross section in FIG. 4 conforms to the position of the cross section in FIG. FIG. 5 is an exploded perspective view showing an arrangement example of the light diffusing portion 164 in the light guide plate 160 according to the embodiment. Note that in FIGS. 4 and 5, the diffusion cover 140 is not shown. In FIG. 5, the approximate boundary between the front surface portion 166 and the curved portion 165 is represented by a alternate long and short dash line. This also applies to FIG. 6 described later.

As shown in FIG. 5, the incident portion 161 of the light guide plate 160 has a first incident surface 162a and a second incident surface 163a. The first incident surface 162a is an end surface on which a part of the light emitted by the light emitting element 21 is incident, and is an end surface for directing the incident light toward the front surface portion 166 of the light guide plate 160. The second incident surface 163a is an end surface on which a part of the light emitted by the light emitting element 21 is incident, and is an end surface in which the incident light is diffused by the incident portion 161 and emitted to the outside.

That is, the incident portion 161 according to the present embodiment functions as a light incident surface that directs the incident light toward the front portion 166, which is the main emission region of the illumination light, and is outward and lateral (in FIG. 4). It has a function as a diffuser lens that diffuses and emits light on the positive side of the Y-axis).

More specifically, the incident portion 161 has a first incident portion 162 having a first incident surface 162a and a second incident portion 163 having a second incident surface 163a, as shown in FIG. In the present embodiment, the first incident portion 162 and the second incident portion 163 are integrated. That is, when the light guide plate 160 is manufactured by, for example, injection molding a resin material, the incident portion 161 in which the first incident portion 162 and the second incident portion 163 are integrated is molded by the mold used for injection molding. can do.

In the incident portion 161 configured in this way, the light emitting element 21 is arranged at a position where, for example, the optical axis La passes through the first incident surface 162a. In other words, the incident portion 161 is arranged at a position where the first incident surface 162a and the optical axis La of the light emitting element 21 intersect. That is, the light emitted from the light emitting element 21 is mainly incident on the first incident surface 162a and is used as the illumination light emitted from the front surface portion 166. Further, in FIG. 4, the light emitted from the light emitting element 21 and heading to the right is incident on the second incident surface 163a, diffused by the second incident portion 163, and emitted. As a result, light can be emitted toward the end of the diffusion cover 140 that does not face the light guide plate 160 (see FIG. 3), and as a result, the end of the diffusion cover 140 can also be illuminated in appearance. This contributes to the improvement of the uniformity of the light emitted by the lighting device 100.

When it is desired to collect light from the outer peripheral portion of the diffusion cover 140, the light emitted from the light emitting element 21 may be mainly incident on the second incident surface 163a. That is, one of the first incident surface 162a and the second incident surface 163a has a position or shape in which the proportion of the light emitted from the light emitting element 21 incident on one of them is higher than the proportion incident on the other. It may be formed in. As a result, in plan view, the balance between the brightness of the illumination light emitted from the central portion of the illumination device 100 and the brightness of the illumination light emitted from the outer peripheral portion of the illumination device 100 is, for example, the specifications required for the illumination device 100. It can be adjusted according to.

Further, it is not essential that the first incident portion 162 and the second incident portion 163 are integrated, and the first incident portion 162 and the second incident portion 163 may be separate bodies. For example, by connecting the second incident portion 163 formed in an annular shape to the outer circumference of the light guide plate 160 having the first incident portion 162 by fitting, bonding, welding, or the like, the first incident portion 162 and the second incident portion 162 are secondly incident. An incident portion 161 having a portion 163 may be formed.

Further, in the present embodiment, the light guide plate 160 has an opening 168 provided in the front surface portion 166, and a tapered surface 168a is formed on the peripheral edge of the opening 168 as shown in FIG. .. The tapered surface 168a is formed so as to be inclined toward the center of the opening 168 as it approaches the diffusion cover 140.

The opening 168 is a portion necessary for accessing the attachment 30 arranged in the central portion of the lighting device 100 from the outside of the lighting device 100, but since it is a non-light emitting region in the light guide plate 160, it is a dark portion in a plan view. May be observed as. Therefore, in the present embodiment, by providing the tapered surface 168a on the peripheral edge of the opening 168, light is emitted from the tapered surface 168a toward the center and the front of the lighting device 100. As a result, the possibility that the central portion of the lighting device 100 is observed as a dark portion is reduced.

Further, in the present embodiment, as shown in FIG. 4, an optical control unit 167 formed by arranging a plurality of recesses 167a is provided on the back surface 166b of the front surface portion 166 of the light guide plate 160. That is, the optical control unit 167 can direct a part of the direction of the light that has reached the back surface 166b inside the light guide plate 160 toward the front surface 166a by the recess 167a. As a result, the efficiency of extracting light from the front surface 166a of the light guide plate 160 is improved. Specifically, in the present embodiment, the optical control unit 167 is provided in substantially the entire area of the back surface 166b of the front surface portion 166. The plurality of recesses 167a are formed, for example, by irradiating the back surface 166b with a laser beam. Further, a plurality of recesses 167a may be formed by the mold used for manufacturing the light guide plate 160. Further, instead of the plurality of concave portions 167a, the optical control unit 167 formed by arranging the plurality of convex portions may be provided on the back surface 166b.

Further, in the present embodiment, the reflective surface portion 112 of the main body portion 110 is arranged at a position facing substantially the entire back surface 166b of the front surface portion 166 (see FIG. 2). Therefore, the light leaking to the outside from the back surface 166b of the front surface portion 166 can be re-entered into the front surface portion 166 by the reflecting surface portion 112. This also makes it possible to improve the efficiency of extracting light from the front surface 166a of the light guide plate 160.

Here, when the light control unit 167 is provided on the back surface 166b, when the nightlight 71 (see FIG. 5) located directly below the back surface 166b (directly above in normal use) is lit, the light control unit 167 forms a dot shape. Shadows may be formed on the diffusion cover 140. The nightlight 71 is an example of a second light source unit when the light source unit 20 is the first light source unit.

Specifically, when the nightlight 71 is turned on, the light source unit 20 is turned off, so that the light incident on the light guide plate 160 is only the light emitted by the nightlight 71. Further, as described above, in the lighting device 100 according to the present embodiment, the distance between the inner surface of the diffusion cover 140 and the light guide plate 160 can be reduced, so that the diffusion cover 140 is the front surface portion of the light guide plate 160. It is located relatively close to 166. When the nightlight 71 is turned on in this state, the light of the nightlight 71 enters the light control unit 167 provided on the back surface 166b from the outside, passes through the front surface 166a, and reaches the diffusion cover 140. At this time, since the optical control unit 167 is provided with a plurality of concave portions 167a (or convex portions) side by side, the uneven shape is easily noticeable. Specifically, dot-shaped shadows corresponding to the uneven shape are likely to occur on the diffusion cover 140. Therefore, in the present embodiment, the light diffusing unit 164 is provided at a position of the light guide plate 160 facing the nightlight 71. That is, when the light guide plate 160 is viewed from the front surface 166a side, the light diffusing portion 164 is provided at a position overlapping the nightlight 71. In the present embodiment, the light diffusing portion 164 is formed by embossing a part of the front surface 166a of the light guide plate 160. As a result, the light that has passed through the light control unit 167 is diffused by the light diffusion unit 164, and as a result, the dot-shaped shadow caused by the light emitted by the nightlight 71 is less likely to occur in the diffusion cover 140. Further, since the light source unit 20 is arranged to face the incident portion 161 of the light guide plate 160, the degree of freedom in the arrangement position of the nightlight 71 arranged to face the back surface 166b of the light guide plate 160 is high.

In the present embodiment, the nightlight 71 is arranged inside the cylinder 70 as shown in FIG. 5, and the light guide plate 160 has a light diffusing portion in a region facing the upper opening of the cylinder 70. 164 is provided. The light diffusing unit 164 is inconspicuous when the lighting device 100 is normally lit (that is, the light source unit 20 is emitting light), and is covered with the diffusing cover 140. Therefore, there is no problem in appearance. Substantially does not occur. Further, the light diffusing portion 164 does not need to be formed of minute irregularities formed on the back surface 166b. For example, the light diffusing portion may be formed by arranging the light diffusing layer, which is a resin layer containing the light diffusing particles, at a position facing the nightlight 71 on the back surface 166b.

Further, the problem of dot-shaped shadows when the nightlight 71 is lit can be solved by increasing the distance between the diffusion cover 140 and the light guide plate 160, for example, but in this case, the thickness of the lighting device 100 increases. , Not a preferred solution. Further, by providing the light guide plate 160 with an opening (through hole) for passing the light of the nightlight 71, it is possible to prevent the diffusion cover 140 from having a dot-shaped shadow. However, in this case, since the opening (through hole) is a non-light emitting region of the light guide plate 160 during normal lighting of the lighting device 100, the opening (through hole) is visually observed as a dark part. .. Therefore, this method cannot be practically adopted either. From such a viewpoint, it can be said that the above-mentioned method of making the dot-shaped shadows less likely to be generated by the light diffusing portion 164 is highly effective and useful.

Further, in the present embodiment, when the light guide plate 160 is viewed from the front surface 166a side, a light receiving unit that receives light transmitted from an external device for operating the lighting device 100 at a position overlapping the light diffusing unit 164. 75 are arranged. The light receiving unit 75 receives, for example, infrared light transmitted from a dedicated remote controller for operating the lighting device 100. The light receiving unit 75 transmits a signal corresponding to the received infrared light to the circuit board 50 (see FIG. 5), and the circuit board 50 turns on, turns off, dimming, and toning the light source unit 20 according to the signal. To control. Since the light receiving portion 75 is present on the back side of the light diffusing portion 164 of the light guide plate 160, the light receiving portion 75 can easily receive infrared light. Specifically, the infrared light transmitted from the outside of the lighting device 100 and passing through the diffusion cover 140 is diffused by the light diffusion unit 164 to improve the reachability to the light receiving unit 75. That is, the possibility that the infrared light transmitted from the outside is totally reflected by the light guide plate 160 is reduced. Therefore, when the light receiving unit 75 is arranged on the back side of the light guide plate 160, the light receiving unit 75 can be ensured to receive light by arranging the light receiving unit 75 at a position overlapping the light diffusing unit 164 in the front view. ..

The positions of the light control unit 167 and the light diffusion unit 164 on the front surface portion 166 of the light guide plate 160 may be reversed. That is, the light control unit 167 may be provided on the front surface 166a of the front surface portion 166, and the light diffusion unit 164 may be provided on the back surface 166b of the front surface portion 166. Even in this case, since the light emitted from the nightlight 71 is diffused by the light diffusing unit 164, the generation of dot-shaped shadows when the nightlight 71 is turned on is suppressed. Further, in this case, the light control unit 167 can function as a light extraction unit for improving the light extraction efficiency to the outside by having a plurality of concave portions or convex portions.

Here, the light guide plate 160 has a curved portion 165 that connects the incident portion 161 and the front surface portion 166, so that the light from the light source portion 20 placed flat on the main body portion 110 is arranged toward the front. It can be discharged to the outside from the front portion 166 (the normal direction is made parallel to the front-rear direction). However, since the curved portion 165 is a portion where light is not easily emitted, when the lighting device 100 arranged on the ceiling is looked up from below, the curved portion 165 is recognized as a dark portion in the illumination light emitting region of the lighting device 100. May be done.

Therefore, the light guide plate 160 can be provided with a light extraction unit for eliminating the dark portion. This light extraction unit will be described with reference to FIGS. 6 to 8.

FIG. 6 is a plan view showing an arrangement example of the light extraction unit 180 in the light guide plate 160 according to the embodiment. FIG. 7 is a cross-sectional view showing an example of the shape of the light extraction unit 180 according to the embodiment, and FIG. 8 is a cross-sectional view showing another example of the shape of the light extraction unit 180 according to the embodiment.

As shown in FIGS. 6 to 8, a convex (FIG. 7) or concave (FIG. 8) light extraction portion 180 can be provided on the outer surface of the curved portion 165 of the light guide plate 160.

Specifically, as shown in FIGS. 6 to 8, the light extraction unit 180 extends the incident portion 161 at a position opposite to the plurality of light emitting elements 21 with the incident portion 161 of the light guide plate 160 interposed therebetween. It is provided continuously in the direction. In the present embodiment, the incident portion 161 is arranged in an annular shape corresponding to the plurality of light emitting elements 21 arranged in an annular shape, and the light extraction unit 180 also sees the light guide plate 160 from the front surface 166a side. In the case (that is, in a plan view), the light guide plate 160 is provided in an annular shape.

More specifically, as shown in FIG. 7, the light extraction portion 180 can be realized as an annular convex portion 181 having a convex shape from the outer surface of the curved portion 165 of the light guide plate 160. The annular convex portion 181 has an optical axis of the light source unit 20, that is, a flat surface portion 181a orthogonal to the optical axis La of the light emitting element 21. As a result, of the light that is about to pass through the curved portion 165, at least a part of the light that has reached the light extraction portion 180 (annular convex portion 181) is emitted from the flat surface portion 181a toward the front. As a result, the possibility that the curved portion 165 is visually recognized as a dark portion is reduced.

Further, as shown in FIG. 8, the light extraction portion 180 can be realized as a concave annular recess 182 from the outer surface of the curved portion 165 of the light guide plate 160. The annular recess 182 has an optical axis of the light source unit 20, that is, a flat surface portion 182a orthogonal to the optical axis La of the light emitting element 21. As a result, of the light that is about to pass through the curved portion 165, at least a part of the light that has reached the light extraction portion 180 (annular recess 182) is emitted from the flat surface portion 182a toward the front. As a result, the possibility that the curved portion 165 is visually recognized as a dark portion is reduced.

The cross-sectional shape of the light extraction unit 180 is not limited to the shapes shown in FIGS. 7 and 8. For example, the light extraction portion 180 can be realized by a convex portion or a concave portion having various cross-sectional shapes such as a semicircular convex portion or a concave portion or a V-shaped convex portion or a concave portion.

Further, when the light guide plate 160 is manufactured by injection molding a resin material, for example, the light guide plate 160 including the light extraction portion 180 integrally can be manufactured by the mold used for the injection molding. The light extraction unit 180 does not need to be integrally formed with the light guide plate 160. For example, the light extraction unit 180 manufactured as a separate member is attached to the light guide plate 160 by fitting, bonding, welding, or the like. You may.

[6. Effect, etc.]
As described above, in the lighting device 100 according to the present embodiment, the light source unit 20 and the light emitted from the light source unit 20 and incident from the end surface (first incident surface 162a) are directed to the front surface. It includes a light source plate 160 that emits light from 166a. The light guide plate 160 is outwardly oriented so as to change the course of light between the incident portion 161 forming the end surface (first incident surface 162a), the front portion 166 forming the front surface 166a, and the incident portion 161 and the front surface portion 166. It has a convex curved portion 165. A concave or convex light extraction portion 180 is provided on the outer surface of the curved portion 165.

According to this configuration, the light guide plate 160 can emit the light incident from the incident portion 161 provided at the end portion from the front surface 166a directed to the front. That is, in a state where the substrate 25 (see FIG. 3) of the light source unit 20 is placed flat on the main body unit 110, light can be emitted forward from the front surface 166a, which is a portion of the light guide plate 160 having a large area. Therefore, the lighting device 100 can be made thinner. Further, the curved portion 165 of the light guide plate 160 is a portion that is easily observed as a dark portion, but the occurrence of the dark portion is suppressed by providing the light extraction portion 180 in the curved portion 165. As a result, the light emitted by the lighting device 100 is made uniform. As described above, the lighting device 100 according to the present embodiment can be made thinner and the uniformity of the emitted light can be improved.

Further, in the present embodiment, the light source unit 20 has a plurality of light emitting elements 21 arranged side by side in the extending direction of the incident unit 161 at a position facing the incident unit 161 of the light guide plate 160. The light extraction unit 180 is provided continuously in the extending direction of the incident portion 161 at positions opposite to the plurality of light emitting elements 21 with the incident portion 161 of the light guide plate 160 interposed therebetween.

According to this configuration, the light guide plate 160 is continuously provided with the light extraction unit 180 along the row of the light emitting elements 21 formed in the light source unit 20. As a result, the dark portion in the curved portion 165 can be eliminated in substantially the entire area where the light source portion 20 is emitting light.

Further, in the present embodiment, the incident portion 161 and the light extraction portion 180 are formed in an annular shape surrounding the front surface portion 166 when the light guide plate 160 is viewed from the front surface 166a side.

According to this configuration, the lighting device 100 can be realized as a lighting device called, for example, a ceiling light as shown in FIGS. 1 and 2. In the present embodiment, the plurality of light emitting elements 21, the incident portion 161 and the light extraction portion 180 are arranged in an annular shape, but these components are formed in a polygonal annular shape such as a square annular shape. It may be arranged. Further, the shape of the annular shape does not have to be completely continuous all around, for example, the incident portion 161 is recognized as an annular shape as a whole by arranging the portions separated from each other at intervals. It may be arranged in a layout. In this case, the plurality of light emitting elements 21 and the light extraction unit 180 may be configured by an array of portions separated from each other corresponding to the incident unit 161 arranged separately.

Further, in the present embodiment, as shown in FIGS. 7 and 8, the light extraction unit 180 has a flat surface portion 181a or 180a orthogonal to the optical axis of the light source unit 20.

According to this configuration, the light incident from the incident unit 161 and reaching the light extraction unit 180 is efficiently emitted from the flat surface unit 181a (182a) toward the front (direction of the optical axis of the light source unit 20). Can be done. That is, the generation of the dark portion in the curved portion 165 can be suppressed more reliably.

Further, in the present embodiment, the lighting device 100 includes a diffusion cover 140 that covers the light source unit 20 and the light guide plate 160 and diffuses and emits the incident light.

According to this configuration, the light emitted from the pseudo surface light source formed on the light guide plate 160 by the light from the light source unit 20 can be further diffused and emitted by the diffusion cover 140.

As a result, for example, even if there is a difference between the light emitted from the front surface 166a of the light guide plate 160 and the light emitted from the light extraction portion 180 of the curved portion 165, the difference is conspicuous by the diffusion cover 140. Can be avoided. That is, according to the diffusion cover 140, the uniformity of the light emitted by the lighting device 100 can be further improved.

(Other embodiments)
The lighting device according to the present invention has been described above based on the embodiment, but the present invention is not limited to the above embodiment.

For example, the lighting device 100 according to the embodiment has a circular shape in a plan view, but the shape of the lighting device 100 is not particularly limited. For example, the lighting device 100 may have a polygonal shape such as a rectangle, a cross shape, or a star shape in a plan view, or may have a shape in which a straight line and a curved line are combined. For example, when the shape of the lighting device 100 in a plan view is rectangular, the arrangement shape of the plurality of light emitting elements 21 and the outer shape of the light guide plate 160 are also rectangular or a shape close to a rectangle, so that a wide range of the rectangular diffusion cover 140 can be obtained. Can emit light from.

Further, it is not essential that the lighting device 100 includes the diffusion cover 140. The light guide plate 160 has a portion in which the front surface portion 166 functions as a pseudo surface light source and further functions as another pseudo light source such as the second incident portion 163. Therefore, the light emitted from the light guide plate 160 can be used as it is as the illumination light. In this case, by not providing the diffusion cover 140, the total luminous flux of the light emitted by the lighting device 100 can be improved.

Further, the light source unit 20 may have a row of double annular light emitting elements 21. In this case, the row of light emitting elements 21 on the inner peripheral side is arranged at a position facing the first incident surface 162a (see FIG. 4), and the row of light emitting elements 21 on the outer peripheral side is arranged on the second incident surface 163a (FIG. 4). It may be arranged at a position opposite to (see). Thereby, for example, a larger amount of light can be emitted from the light guide plate 160 to a wider range of the diffusion cover 140, and as a result, the uniformity of the light emitted by the illuminating device 100 is improved and the total luminous flux is increased. Improvement is planned.

Further, the plurality of light emitting elements 21 included in the light source unit 20 do not need to be arranged in a ring shape. The plurality of light emitting elements 21 may be arranged along only one non-annular straight line or curve. For example, when a plurality of light emitting elements 21 are arranged in a straight line, an incident portion provided along one side of a rectangular light guide plate may be arranged so as to face the plurality of light emitting elements 21. In this case, in appearance, a long lighting device may be configured in the direction in which the plurality of light emitting elements 21 are arranged.

Further, in the present embodiment, the light guide plate 160 is formed so that a pseudo surface light source is formed in the central portion of the lighting device 100 in a plan view by the light from the plurality of light emitting elements 21. However, the light guide plate may be formed so that a pseudo surface light source is formed on the outer peripheral side of the lighting device in a plan view. For example, a light guide plate having an end face facing a plurality of light emitting elements 21 arranged in an annular shape and a front surface located outside the plurality of light emitting elements 21 in a plan view and facing forward is adopted in the lighting device. You may. Even in this case, since the curved portion is provided between the end face and the front surface, the generation of the dark portion in the curved portion is suppressed by providing the light extraction portion in the curved portion.

Further, the light emitting element 21 is an SMD type LED element, but the present invention is not limited to this. For example, the light source unit 20 may have a COB (Chip On Board) structure in which an LED chip as a light emitting element 21 is directly mounted on a substrate 25. In this case, a plurality of LED chips mounted on the substrate 25 are collectively sealed by a sealing member containing a wavelength conversion material, or individually sealed to obtain illumination light having a predetermined color temperature. be able to.

Further, a semiconductor light emitting device such as a semiconductor laser, or another type of solid light emitting element such as an EL element such as an organic EL (Electroluminescence) or an inorganic EL may be adopted as the light emitting element 21.

In addition, a form obtained by applying various modifications to the above-described embodiment and its modification, and components and functions in each embodiment and its modification without departing from the spirit of the present invention. The present invention also includes a form realized by arbitrarily combining the above.

20 Light source 21 Light emitting element 25 Board 71 Nightlight 75 Light receiving part 100 Lighting device 110 Main body 140 Diffuse cover 160 Light guide plate 161 Incident part 162 First incident part 162a First incident surface 163 Second incident part 163a Second incident surface 164 Light Diffusing part 165 Curved part 166 Front part 166a Front part 166b Back side 167 Light control part 167a Recessed part 168a Tapered surface 180 Light extraction part 181 Circular convex part 181a, 182a Flat part 182 Circular concave part

Claims (5)

Light source and
It is provided with a light guide plate that emits light emitted from the light source unit and incident from the end face from the front surface facing forward.
The light guide plate has an incident portion forming the end face, a front surface portion forming the front surface, and an outwardly convex curved portion that changes the course of light between the incident portion and the front surface portion. ,
A lighting device provided with a concave or convex light extraction portion on the outer surface of the curved portion. The light source unit has a plurality of light emitting elements arranged side by side in the extending direction of the incident portion at a position facing the incident portion of the light guide plate.
The light extraction portion is provided continuously in the extending direction of the incident portion at a position opposite to the plurality of light emitting elements with the incident portion of the light guide plate interposed therebetween.
The lighting device according to claim 1. The incident portion and the light extraction portion are formed in an annular shape surrounding the front surface portion when the light guide plate is viewed from the front surface side.
The lighting device according to claim 1 or 2. The lighting device according to any one of claims 1 to 3, wherein the light extraction unit has a flat surface portion orthogonal to the optical axis of the light source unit. Further, a diffusion cover that covers the light source unit and the light guide plate and diffuses and emits the incident light is provided.
The lighting device according to any one of claims 1 to 4.

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