JP7680665B2 - Light-emitting device - Google Patents

Description

This disclosure relates to a light emitting device.

Light-emitting devices are known that control the distribution of light to the walls and floors of a store or to signs installed in the store in order to create a spatial effect in the store or other facilities. Another light-emitting device disclosed is one that includes multiple LED elements and multiple rods that guide the light emitted by the LED elements, with the emission surfaces of the multiple rods arranged close to each other, in contact with each other, or integrated together (see, for example, Patent Document 1).

JP 2015-088410 A

However, in the device of Patent Document 1, the distance between the light source, such as an LED element, and the light-guiding member, such as a rod, may vary.

The present disclosure aims to suppress fluctuations in the distance between the light source and the light-guiding member.

A light emitting device according to one embodiment of the present disclosure includes a light source that emits light, a light guiding member that guides the light, a defining member that is provided between a mounting surface on which the light source is mounted and a light incident end surface of the light guiding member into which the light is incident and defines the distance between the light source and the light guiding member, and a holding portion that is joined to a surface of the light guiding member that intersects with the light incident end surface and holds an end portion of the light guiding member on the light incident end surface side, the defining member including a first contact portion that contacts the mounting surface and a second contact portion that contacts the holding portion.

According to one embodiment of the present disclosure, fluctuations in the distance between the light source and the light-guiding member can be suppressed.

1A and 1B are diagrams showing an example of the overall configuration of a light emitting device according to an embodiment, in which FIG. 1A is a perspective view seen from the light irradiation direction side, and FIG. 1B is a perspective view seen from the opposite side to the light irradiation direction. 1 is an exploded perspective view showing an example of the overall configuration of a light emitting device according to an embodiment; 11A to 11C are diagrams showing examples of methods for fixing a narrow-angle light-guiding member and a wide-angle light-guiding member to a holder member. 4 is a plan view of an example of the arrangement of a narrow-angle light-guiding member, a wide-angle light-guiding member, and LEDs according to the embodiment. FIG. 4 is an exploded perspective view showing an example of the configuration of the narrow-angle light-guiding member group and its periphery according to the embodiment; FIG. 4 is a cross-sectional view showing an example of the configuration of the periphery of a narrow-angle light-guiding member group according to the embodiment; FIG. 7A and 7B are cross-sectional views showing examples of light guiding by a narrow-angle light-guiding member according to an embodiment, where FIG. 7A is a view of a first example and FIG. 7B is a view of a second example. 1A to 1C are diagrams illustrating an example of light irradiation by a light emitting device according to an embodiment. 9A and 9B are cross-sectional views showing examples of bonding between a narrow-angle light-guiding member and a holder according to modified examples, where FIG. 9A is a view of a first modified example, and FIG. 9B is a view of a second modified example.

Below, a description will be given of an embodiment of the invention with reference to the drawings. In the following description, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components.

The embodiments shown below are illustrative of a light-emitting device for embodying the technical concept of the present invention, and the present invention is not limited to the embodiments shown below. Unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended to be illustrative and not to limit the scope of the present invention. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated for clarity.

In the figures shown below, directions may be indicated by the X-axis, Y-axis, and Z-axis, but the X-direction along the X-axis indicates a specific direction in the array plane in which the multiple light sources provided in the light-emitting device of the embodiment are arranged, the Y-direction along the Y-axis indicates a direction perpendicular to the X-direction in the array plane, and the Z-direction along the Z-axis indicates a direction perpendicular to the array plane.

The direction in which the arrow points in the X direction is denoted as the +X direction, and the opposite direction of the +X direction is denoted as the -X direction, the direction in which the arrow points in the Y direction is denoted as the +Y direction, and the opposite direction of the +Y direction is denoted as the -Y direction, and the direction in which the arrow points in the Z direction is denoted as the +Z direction, and the opposite direction of the +Z direction is denoted as the -Z direction. In the embodiment, the light emitting device irradiates light in the +Z direction, as an example. However, this does not limit the orientation of the light emitting device when in use, and the orientation of the light emitting device is arbitrary.

<Configuration of Light-Emitting Device 1>
First, the configuration of a light emitting device 1 according to an embodiment will be described.

(Overall configuration example)
Figure 1 is a diagram illustrating an example of the overall configuration of a light-emitting device 1, where Figure 1(a) is an oblique view of the light-emitting device 1 viewed from the light irradiation direction (+Z direction), and Figure 1(b) is an oblique view of the light-emitting device 1 viewed from the -Z direction.

As shown in FIG. 1(a), the light-emitting device 1 has an opening 10 on the front side (+Z direction side) through which light passes, and is formed into a roughly cylindrical shape. As shown in FIG. 1(b), the light-emitting device 1 has a connector 21 on the back side (-Z direction side) for electrically connecting to a drive circuit 2. A drive voltage supplied from the drive circuit 2 is applied to a light source housed inside the light-emitting device 1 via the connector 21 and an FPC (Flexible Printed Circuits) 22. The light-emitting device 1 can irradiate light emitted by the application of a drive voltage to the +Z direction side through the opening 10.

The light-emitting device 1 is fixed, for example, to a wall or ceiling of a building and used as a lighting device that illuminates the interior or exterior space of the building. Alternatively, it is fixed to a wall or ceiling of a store facility and used as a downlight, spotlight, indirect lighting, etc. for spatial presentation of the store facility. The light-emitting device 1 can also be mounted on a moving object such as a vehicle and used as a headlight for illuminating the surroundings of the moving object.

Note that, although FIG. 1 illustrates a light-emitting device 1 having an approximately cylindrical outer shape, this is not limited thereto, and the light-emitting device 1 can be formed into any outer shape, such as a rectangular column.

Next, FIG. 2 is an exploded perspective view illustrating an example of the overall configuration of the light-emitting device 1. As shown in FIG. 2, the light-emitting device 1 has a rear substrate 11, a heat dissipation member 12, an LED (Light Emitting Diode) mounting substrate 13, a spacer 14, a holder member 15, a narrow-angle light-guiding member array 16, and a wide-angle light-guiding member array 17.

The rear substrate 11, heat dissipation member 12, LED mounting substrate 13, spacer 14 and holder member 15 are stacked in this order along the Z direction and fixed by screwing the fixing screw 19 into the female threaded hole provided in the holder member 15.

The narrow-angle light-guiding member array 16 is inserted into the narrow-angle through-hole 151 from the +Z direction side and fixed by fitting or the like, and the wide-angle light-guiding member array 17 is inserted into the wide-angle through-hole 152 from the -Z direction side and fixed by fitting or the like. Note that the method is not limited to fitting, and fixing may also be done with an adhesive or the like.

The rear substrate 11 is a plate-like member having a roughly circular outer shape, and is a substrate equipped with wiring on which various electrical elements can be mounted. The rear substrate 11 has a connector 21 on the surface facing in the -Z direction, allowing connection to the drive circuit 2 via an electrical cable or the like. The rear substrate 11 can be, for example, a two-layer printed circuit board based on a metal such as aluminum or copper. Substrates other than a metal base, such as a paper epoxy board or a glass epoxy board, can also be used, but a metal-based board is preferable in terms of heat dissipation.

The heat dissipation member 12 is a cylindrical member having a roughly circular outer shape. The heat dissipation member 12 is made of a material with good heat dissipation properties, such as aluminum. The heat dissipation member 12 is provided in contact with the LED mounting board 13, and heat generated by driving the LEDs 131 on the LED mounting board 13 is dissipated through the heat dissipation member 12.

The LED mounting board 13 is a substantially circular plate-like member that is equipped with wiring on which light sources such as LEDs and various electrical elements can be mounted. The material of the LED mounting board 13 is the same as that of the rear board 11, so a duplicated description will be omitted.

The LED mounting board 13 is electrically connected to the rear substrate 11 via a connector provided on the LED mounting board 13 and an FPC 22. The LED mounting board 13 also includes multiple LEDs 131. Note that LED 131 is a general term for multiple LEDs.

Each LED 131 is an example of a light source that emits light, and is mounted on the mounting surface 132, which is the surface on the +Z direction side of the LED mounting board 13. Each LED 131 is electrically connected to the drive circuit 2 via the LED mounting board 13 and the FPC 22, etc., and emits light in response to a drive voltage applied from the drive circuit 2.

The LED 131 emits, for example, white light, but is not limited to this and may emit monochromatic light, and among the white light, various colors such as incandescent white, neutral white, and daylight white can be selected.

For example, LED 131 may be manufactured by Nichia Corporation under the product number NFSWE11A. From the viewpoint of the efficiency of light incidence on each of the narrow-angle light-guiding member array 16 and the wide-angle light-guiding member array 17, it is preferable to reduce the amount of light directed from LED 131 in the lateral direction.

The spacer 14 is an example of a determining member that is provided between the light incident end face 161i and the light incident end face 171i and the mounting surface 132 on which the LED 131 is placed, and determines the distance between the narrow-angle light-guiding member 161 and the wide-angle light-guiding member 171 and the LED 131.

Here, the light incident end surface 161i is an end surface included in the narrow-angle light-guiding member 161 of the narrow-angle light-guiding member array 16, and is arranged opposite the LED 131, and is an end surface through which light emitted by the LED 131 enters the narrow-angle light-guiding member 161. Note that the narrow-angle light-guiding member 161 is a general term for the multiple narrow-angle light-guiding members included in the narrow-angle light-guiding member array 16. The light incident end surface 161i is a general term for each of the light incident end surfaces of the multiple narrow-angle light-guiding members 161. The configuration of the narrow-angle light-guiding member 161 will be described separately with reference to Figures 5 and 6.

The light incident end surface 171i is an end surface included in the wide-angle light-guiding member 171 of the wide-angle light-guiding member array 17, and is disposed opposite the LED 131, and is an end surface through which light emitted by the LED 131 enters the wide-angle light-guiding member 171. Note that the wide-angle light-guiding member 171 is a general term for the multiple wide-angle light-guiding members included in the wide-angle light-guiding member array 17. The light incident end surface 171i is a general term for each of the light incident end surfaces of the multiple wide-angle light-guiding members 171.

The spacer 14 is a substantially circular plate-like member, and has a number of rectangular spacer through-holes 141 at positions that correspond one-to-one to each of the LEDs 131 mounted on the LED mounting substrate 13 when the spacer 14 is overlaid on the LED mounting substrate 13. Note that the spacer through-holes 141 are a collective term for the multiple spacer through-holes.

The spacer 14 can be manufactured by forming spacer through-holes 141 in a plate-shaped member using a laser processing method or the like. There are no particular restrictions on the material of the spacer 14, but aluminum is preferable because it has sufficient strength to prevent the gap from fluctuating over time and has high heat dissipation properties against heat generated by the LED 131. It is also more preferable to subject the spacer 14 to a surface treatment such as blackening in order to reduce flare light or ghost light.

The -Z side of the planar area of the spacer 14 other than the area where the spacer through-holes 141 are formed contacts the surface of the LED mounting board 13 on which the LEDs 131 are placed, and the +Z side of the planar area contacts the holding portion 162 included in the narrow-angle light-guiding member array 16. In this state, the rear substrate 11, heat dissipation member 12, LED mounting board 13, and spacer 14 are stacked and fixed to the holder member 15. The holding portion 162 is a member that holds each of the narrow-angle light-guiding member 161 and the wide-angle light-guiding member 171, and is a general term for multiple holding portions.

This defines a predetermined distance between the light emitting surface of the LED 131, which faces the spacer through hole 141, and the light incident end surface 161i of the narrow-angle light-guiding member array 16.

The rear substrate 11, heat dissipation member 12, LED mounting substrate 13, and spacer 14 are overlapped with positioning pins 18 inserted into positioning through holes provided at predetermined positions on each component. These positioning pins 18 are then fitted into positioning recesses provided on the holder component 15. This aligns the positions of the rear substrate 11, heat dissipation member 12, LED mounting substrate 13, and spacer 14, and the narrow-angle light-guiding component array 16 and wide-angle light-guiding component array 17 fixed to the holder component 15 in a predetermined state within the respective array planes.

The holder member 15 is a cylindrical member having twelve narrow-angle through holes 151 and four wide-angle through holes 152. The narrow-angle light-guiding member 161 is inserted into and fixed in the narrow-angle through holes 151, and the wide-angle light-guiding member 171 is inserted into and fixed in the wide-angle through holes 152. Here, FIG. 3 is a diagram illustrating an example of a method for fixing the narrow-angle light-guiding member 161 and the wide-angle light-guiding member 171 to the holder member 15.

As shown in FIG. 3, the narrow-angle light-guiding member 161 is inserted into the narrow-angle through-hole 151 from the +Z direction side along the direction indicated by the arrow 31, and after the holding portion 162 passes through the narrow-angle through-hole 151, it is abutted against the spacer 14 arranged on the -Z direction side of the holder member 15. Then, the stopper member 163, which is a sheet metal plate formed into an approximately U-shape, is inserted between the holding portion 162 and the bottom surface 153 of the holder member 15, and the narrow-angle light-guiding member 161 is fixed by sandwiching the holding portion 162 between the stopper member 163 and the spacer 14.

On the other hand, the wide-angle light-guiding member 171 is inserted into the wide-angle through-hole 152 from the -Z direction side along the direction indicated by the arrow 32, and is fixed in place by abutting the +Z direction surface of the holding portion 162 against the abutment portion 154 included in the holder member 15.

Returning to FIG. 2, the explanation will continue. Light exit end face 171o is an end face included in wide-angle light-guiding member 171, and is an end face from which guided light is emitted from inside wide-angle light-guiding member 171 to the outside. Light exit end face 161o is an end face included in narrow-angle light-guiding member 161, and is an end face from which guided light is emitted from inside narrow-angle light-guiding member 161 to the outside. Note that light exit end face 171o is a collective notation for the light exit end faces of each of the multiple wide-angle light-guiding members 171, and light exit end face 161o is a collective notation for the light exit end faces of each of the multiple narrow-angle light-guiding members 161.

The holder member 15 is manufactured, for example, by injection molding a resin material. In order to prevent the light emitted by the LED 131 from leaking out of the light emitting device 1 to the outside, and to prevent visible light such as sunlight from entering the inside of the light emitting device 1 from the outside, it is preferable that the resin material of the holder member 15 is not transparent to the light emitted by the LED 131 and visible light.

For example, the resin material may be a thermoplastic resin such as polyphenylene sulfide (PPS) resin, polycarbonate (PC) resin, polymethyl methacrylate (PMMA) resin, acrylonitrile butadiene styrene (ABS) resin, or polyether ether ketone (PEEK) resin. However, the material is not limited to resin, and the holder member 15 may be made of a metal material such as an aluminum alloy.

The narrow-angle light-guiding member array 16 has 12 narrow-angle light-guiding member groups 16A arranged in a two-dimensional array on the array plane, and each narrow-angle light-guiding member group 16A has nine narrow-angle light-guiding members 161. Therefore, the narrow-angle light-guiding member array 16 has a total of 108 narrow-angle light-guiding members 161. Note that the narrow-angle light-guiding member group 16A is a general term for the 12 narrow-angle light-guiding member groups. The arrangement of the narrow-angle light-guiding members 161 will be described separately with reference to FIG. 4.

Each narrow-angle light-guiding member 161 has a tapered shape that becomes thinner as it approaches the light-incident end face 161i, and the cross section of the narrow-angle light-guiding member 161 that intersects with the light-guiding direction is formed in a square shape.

Note that a tapered shape refers to a shape in which the diameter, width, thickness, etc. of a thin and long member tapers off. Here, in this embodiment, as long as the shape becomes thinner as it approaches the light incident end face 161i, it is called a taper even if the inclination of the side portion of each narrow-angle light-guiding member 161 is not symmetrical with respect to the central axis of the narrow-angle light-guiding member 161. In this embodiment, the cross section intersecting the central axis of each narrow-angle light-guiding member 161 is formed in a rectangular shape, but is not limited to a rectangular shape and may be another shape such as a circular shape. This is also true for the wide-angle light-guiding member 171.

The wide-angle light-guiding member array 17 has four wide-angle light-guiding member groups 17A arranged in the array plane, and each wide-angle light-guiding member group 17A has nine wide-angle light-guiding members 171. Therefore, the wide-angle light-guiding member array 17 has a total of 36 wide-angle light-guiding members 171. Note that the wide-angle light-guiding member group 17A is a general term for the four wide-angle light-guiding member groups. The arrangement of the wide-angle light-guiding members 171 will be described separately with reference to FIG. 4.

Each wide-angle light-guiding member 171 has a tapered shape that becomes thinner as it approaches the light-incident end face 171i, and the cross section of the wide-angle light-guiding member 171 that intersects with the light-guiding direction is formed in a square shape.

On the light emitting end face 161o side, adjacent narrow-angle light guiding members 161 are connected to each other. Similarly, on the light emitting end face 171o side, adjacent wide-angle light guiding members 171 are connected to each other. The 108 light emitting end faces 161o and 36 light emitting end faces 171o are arranged in the array plane, and form an opening 10 that functions as an opening through which light in the light emitting device 1 exits.

On the light incident end face 161i side of the narrow-angle light-guiding member array 16, adjacent narrow-angle light-guiding members 161 are separated from each other, and the distance between the side faces of adjacent narrow-angle light-guiding members 161 becomes wider as they approach the light incident end face 161i. Similarly, on the light incident end face 171i side of the wide-angle light-guiding member array 17, the distance between the side faces of adjacent wide-angle light-guiding members 171 becomes wider as they approach the light incident end face 171i.

Here, the narrow-angle light-guiding member 161 and the wide-angle light-guiding member 171 are each an example of a light-guiding member.

Light emitted by the LED 131 enters the narrow-angle light-guiding member 161 through the light-incident end face 161i. The incident light is guided through the narrow-angle light-guiding member 161 while repeatedly undergoing total reflection at the tapered side faces of the narrow-angle light-guiding member 161, and is emitted through the light-exiting end face 161o. The taper angle of the narrow-angle light-guiding member 161 is approximately 5.7 degrees, and the spread angle of the emitted light by the narrow-angle light-guiding member 161 is approximately 12.5 degrees. The numerical value of the spread angle represents the half-value half-angle. This also applies below.

The light emitted by the LED 131 enters the wide-angle light-guiding member 171 through the light incident end face 171i. The incident light is guided through the wide-angle light-guiding member 171 while repeatedly undergoing total reflection at the tapered side faces of the wide-angle light-guiding member 171, and exits through the light exit end face 171o. The taper angle of the wide-angle light-guiding member 171 is approximately 1.9 degrees, and the spread angle of the exiting light from the wide-angle light-guiding member 171 is approximately 30.0 degrees.

The narrow-angle light-guiding member array 16 is manufactured by injection molding a resin material that is transparent to the light emitted by the LEDs 131, integrating nine narrow-angle light-guiding members 161. There are 12 narrow-angle light-guiding member groups 16A, each of which is a set of nine narrow-angle light-guiding members 161, and the narrow-angle light-guiding member array 16 is made up of a total of 108 narrow-angle light-guiding members 161. Similarly, the wide-angle light-guiding member array 17 is manufactured by injection molding a resin material that is transparent to the light emitted by the LEDs 131, integrating nine wide-angle light-guiding members 171 for each of four wide-angle light-guiding member groups 17A. Silicone resin, polycarbonate resin, acrylic resin, etc. can be used as the resin material for each of the narrow-angle light-guiding member array 16 and the wide-angle light-guiding member array 17.

The number or arrangement of the LEDs 131, spacer through holes 141, narrow-angle light-guiding members 161, and wide-angle light-guiding members 171 shown in FIG. 2, as well as the external shapes of each member, are merely examples, and can be selected as appropriate depending on the purpose of the light-emitting device 1.

In addition, the "wide angle" in the wide-angle light-guiding member array 17 means that the spread angle of the emitted light is relatively wide compared to the narrow-angle light-guiding member array 16, and is not limited to angles generally called "wide angles." Similarly, the "narrow angle" in the narrow-angle light-guiding member array 16 means that the spread angle of the emitted light is relatively narrow compared to the wide-angle light-guiding member array 17, and is not limited to angles generally called "narrow angles."

In other words, the spread angle of the light emitted from the narrow-angle light-guiding member array 16 should be narrower than the spread angle of the light emitted from the wide-angle light-guiding member array 17.

The taper angle, number, and number of sets of light-guiding members of each light-guiding member in the narrow-angle light-guiding member array 16 and the wide-angle light-guiding member array 17 are not limited to those described above, and can be appropriately selected according to the purpose. In addition, in this embodiment, an example is shown in which light propagates through the light-guiding member by being totally reflected on the side surface of the light-guiding member, but this is not limited to this. It is also possible to provide a deflecting surface such as a reflective surface on the side surface of the light-guiding member, so that the light can propagate through the light-guiding member by being deflected by the side surface of the light-guiding member.

<Example of Arrangement of Narrow-Angle Light-Guiding Member 161, Wide-Angle Light-Guiding Member 171, and LED 131>
Next, Fig. 4 is a plan view illustrating an example of the arrangement of the narrow-angle light-guiding member 161, the wide-angle light-guiding member 171, and the LEDs 131. Fig. 4 shows the light-emitting device 1 as viewed from the +Z direction side.

However, in order to make it easier to understand the arrangement of the narrow-angle light-guiding member 161, the wide-angle light-guiding member 171, and the LEDs 131, FIG. 4 shows only the narrow-angle light-guiding member array 16, the wide-angle light-guiding member array 17, and the LED mounting board 13 including the LEDs 131, among the components of the light-emitting device 1.

As shown in FIG. 4, the narrow-angle light-guiding member array 16 has a total of 12 narrow-angle light-guiding member groups 16A, including two at both ends in the X direction arranged in the Y direction, two at both ends in the Y direction arranged in the X direction, and four narrow-angle light-guiding members arranged in a 2 x 2 arrangement in the center. Each narrow-angle light-guiding member group 16A also has nine narrow-angle light-guiding members 161 arranged in a 3 x 3 arrangement. In FIG. 4, the narrow-angle light-guiding members 161 are shown as thin-lined rectangles, and the narrow-angle light-guiding member group 16A including the 3 x 3 narrow-angle light-guiding members 161 is shown as a thick-lined rectangle.

The wide-angle light-guiding member array 17 also has four wide-angle light-guiding member groups 17A surrounding the narrow-angle light-guiding member array 16 from four diagonal directions. Each wide-angle light-guiding member group 17A also has nine wide-angle light-guiding members 171 in a 3 x 3 arrangement. In FIG. 4, the wide-angle light-guiding members 171 are displayed as thin-lined rectangles that are smaller than the thin-lined rectangles representing the narrow-angle light-guiding members 161. The wide-angle light-guiding member group 17A, which includes 3 x 3 wide-angle light-guiding members 171, is displayed as a thick-lined rectangle.

As shown in FIG. 4, each of the narrow-angle light-guiding member 161 and the wide-angle light-guiding member 171 has a square shape in the array plane, and the area of the narrow-angle light-guiding member 161 is larger than the area of the wide-angle light-guiding member 171.

LEDs 131 are provided in one-to-one correspondence with a total of 108 narrow-angle light-guiding members 161, as shown by blackened rectangles in Figure 4. For each narrow-angle light-guiding member group 16A, the LEDs 131 are arranged in the center so that their centers approximately coincide with the center of the narrow-angle light-guiding member 161, and the LEDs 131 are arranged on the periphery so that their centers are eccentric with respect to the center of the narrow-angle light-guiding member 161. On the periphery of the narrow-angle light-guiding member group 16A, the LEDs 131 are arranged eccentrically with respect to the center of the narrow-angle light-guiding member 161 so that their centers are closer to the center of the narrow-angle light-guiding member group 16A.

For example, the center of the narrow-angle light-guiding member 161c and the center of the LED 131c are approximately aligned. On the other hand, the center of the LED 131f is eccentric to the center of the narrow-angle light-guiding member 161f so as to be closer to the center of the narrow-angle light-guiding member group 16A.

A total of 36 LEDs 131 are provided in one-to-one correspondence with the wide-angle light-guiding members 171. The centers of the wide-angle light-guiding members 171 and the centers of the LEDs 131 that correspond one-to-one to the wide-angle light-guiding members 171 are arranged so that they approximately coincide with each other.

In this embodiment, the LED 131 corresponding to the narrow-angle light-guiding member 161 and the LED 131 corresponding to the wide-angle light-guiding member 171 are both LEDs that emit white light, but this is not limited to the above. For example, the LED corresponding to the narrow-angle light-guiding member 161 may emit white light, and the LED corresponding to the wide-angle light-guiding member 171 may emit light of a light bulb color.

<Example of the configuration around the narrow-angle light-guiding member group 16A>
Next, the configuration of the narrow-angle light-guiding member group 16A will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is an exploded perspective view illustrating an example of the configuration of the narrow-angle light-guiding member group 16A. Fig. 6 is a cross-sectional view illustrating an example of the configuration of the narrow-angle light-guiding member group 16A. Note that Fig. 5 and Fig. 6 show only a portion of the narrow-angle light-guiding member group 16A, the spacer 14, and the LED mounting board 13 that correspond to the narrow-angle light-guiding member group 16A.

As shown in Figures 5 and 6, the narrow-angle light-guiding member group 16A includes a narrow-angle light-guiding member 161 and a holding portion 162. The holding portion 162 is a member that is made of silicone resin containing light-reflective particles and is manufactured by injection molding or the like. The holding portion 162 is a separate member from the narrow-angle light-guiding member array 16.

The holding portion 162 is joined to a surface that intersects with the light incident end face 161i of each narrow-angle light-guiding member 161, and holds the end portion of the narrow-angle light-guiding member 161 on the light incident end face 161i side. In other words, the surface that intersects with the light incident end face 161i of each narrow-angle light-guiding member 161 is a tapered surface on the side of the narrow-angle light-guiding member 161, and the holding portion 162 holds the vicinity of the end portion of the tapered surface on the light incident end face 161i side.

The light-reflective particles are particles that are reflective to the light emitted by the LED 131, such as white titanium oxide particles, glass beads, calcium carbonate particles, aluminum powder, mica particles, etc. The holding portion 162 contains light-reflective particles and is colored white, etc., so that it has low light transmittance. In contrast, the narrow-angle light-guiding member 161 differs in characteristics in that it does not contain light-reflective particles and has high light transmittance. However, the holding portion 162 and the narrow-angle light-guiding member 161 can be formed containing the same material (e.g., silicone resin, polycarbonate resin, or acrylic resin), and the linear expansion coefficients can be made approximately equal, and the amount of deformation due to temperature changes, etc., is approximately equal. The linear expansion coefficient can also be called the linear expansion coefficient, thermal expansion coefficient, or thermal expansion coefficient.

As shown in FIG. 6, the holding portion 162 is joined to the side surface of the narrow-angle light-guiding member 161 that intersects with the light-incident end surface 161i via an adhesive member 20. The adhesive member 20 is made of a resin that contains light-reflective particles and functions as an adhesive. The light-reflective particles are, for example, white titanium oxide particles, glass beads, calcium carbonate particles, aluminum powder, mica particles, etc. Therefore, the adhesive member 20 is colored white, etc., and has low light transmittance.

The holding portion 162 has a low light transmittance, but because it is joined to the side surface that intersects with the light incident end surface 161i of the narrow-angle light-guiding member 161, it does not impede the incidence of light from the LED 131 through the light incident end surface 161i of the narrow-angle light-guiding member 161.

The spacer 14, which is disposed on the -Z side of the holding portion 162, contacts the surface of the holding portion 162 on the -Z side with its surface 14a on the +Z side. The spacer 14 also contacts the mounting surface 132 of the LED mounting board 13 with its back surface 14b on the -Z side. In this state, the narrow-angle light-guiding member array 16 including the narrow-angle light-guiding member 161, the spacer 14, and the LED mounting board 13 are fixed to the holder member 15. Here, the surface 14a of the spacer 14 is an example of a second contact portion that contacts the holding portion 162, and the back surface 14b of the spacer 14 is an example of a first contact portion that contacts the mounting surface 132.

The narrow-angle light-guiding member 161 is joined to the holding portion 162, and the holding portion 162 is in contact with the surface 14a of the spacer 14. Therefore, even if the narrow-angle light-guiding member 161 expands along the light irradiation direction (Z direction) due to thermal expansion or the like, the movement of the light-incident end face 161i toward the LED 131 is suppressed. In other words, the fluctuation in the distance between the light source and the light-guiding member can be suppressed. Note that the narrow-angle light-guiding member 161 thermally expands in the +Z direction based on the surface 14a of the spacer 14, but in the configuration of FIG. 6, no restricting member such as a glass plate for suppressing thermal expansion on the +Z direction side of the narrow-angle light-guiding member 161 is provided, and the light-emitting end face 161o is free to move along the Z direction.

In addition, when the holding portion 162 and the narrow-angle light-guiding member 161 contain the same material, the deformation amounts of the narrow-angle light-guiding member 161 and the holding portion 162 due to temperature changes are approximately equal, so that the shear stress applied to the joint between the narrow-angle light-guiding member 161 and the holding portion 162 due to the difference in the deformation amounts of the two is suppressed. As a result, even if the narrow-angle light-guiding member 161 deforms due to temperature changes, damage such as peeling between the narrow-angle light-guiding member 161 and the holding portion 162 is suppressed.

The narrow-angle light-guiding member 161 can expand and contract in a direction in which the end portion on the light-emitting end face 161o side intersects with the light-emitting end face 161o. The direction intersecting with the light-emitting end face 161o is, for example, a direction along the Z direction. Therefore, when the narrow-angle light-guiding member 161 expands along the light irradiation direction (Z direction) due to thermal expansion or the like, the light-emitting end face 161o is likely to move in the +Z direction.

In addition, if some of the light emitted by the LED 131 propagates in the lateral direction of the LED 131, the efficiency of the light entering the narrow-angle light-guiding member 161 may decrease. However, the holding portion 162 is provided on the side where the radiation angle of the light emitted by the LED 131 is large (±90 degrees), and contains light-reflective particles.

Therefore, by reflecting the light propagating in the lateral direction of the LED 131 and directing it to the light incident end surface 161i, it is possible to suppress a decrease in the efficiency of light incidence into the narrow-angle light-guiding member 161. Here, the propagating light 25 shown in FIG. 6 indicates the light that is reflected by the holding portion 162 and directed to the light incident end surface 161i.

In addition, the adhesive member 20 also contains light-reflective particles, so that the light propagating in the lateral direction of the LED 131 can be reflected and guided to the light incident end surface 161i, thereby acting to suppress a decrease in the efficiency of light incidence into the narrow-angle light-guiding member 161.

Note that, although the configuration around the narrow-angle light-guiding member group 16A has been described in Figures 5 and 6, the wide-angle light-guiding member group 17A can also be provided with a holding portion similar to the holding portion 162 and an adhesive member similar to the adhesive member 20, and can achieve the same effect as the holding portion 162 and the adhesive member 20.

The narrow-angle light-guiding member 161c of the narrow-angle light-guiding member 161 has a light incident end face 161ci and a light emitting end face 161co. The narrow-angle light-guiding member 161c is an example of a first light-guiding member. The central axis 161cc of the narrow-angle light-guiding member 161c is an axis that passes through both the center of the light incident end face 161ci and the center of the light emitting end face 161co.

The narrow-angle light-guiding member 161f of the narrow-angle light-guiding member 161 has a light incident end face 161fi and a light emitting end face 161fo. The narrow-angle light-guiding member 161f is an example of a second light-guiding member. The central axis 161fc of the narrow-angle light-guiding member 161f is an axis that passes through both the center of the light incident end face 161fi and the center of the light emitting end face 161fo.

The central axis 161fc is inclined at an inclination angle θ with respect to the Z direction. The central axis 161cc is not inclined with respect to the Z direction. Therefore, the central axis 161fc and the central axis 161cc are inclined at an inclination angle θ.

The axial distance di is the axial distance between the central axis 161fc and the central axis 161cc on the light incident end face 161i side. The axial distance do is the axial distance between the central axis 161fc and the central axis 161cc on the light emitting end face 161o side. The axial distance do is longer than the axial distance di. In other words, the axial distance between the central axis 161fc and the central axis 161cc is larger on the emission side than on the incidence side.

With this configuration, the light emitting device 1 having the narrow-angle light-guiding member array 16 can emit light whose direction changes as it travels in the +Z direction. Note that the wide-angle light-guiding member array 17 has a different spread angle of the emitted light compared to the narrow-angle light-guiding member array 16, but can emit divergent light that spreads as it travels in the +Z direction, just like the narrow-angle light-guiding member array 16.

<Example of Light Guidance by Narrow-Angle Light-Guiding Member 161>
Next, light guiding by the narrow-angle light-guiding member 161 will be described with reference to Fig. 7. Fig. 7 is a cross-sectional view illustrating an example of light guiding by the narrow-angle light-guiding member 161, Fig. 7(a) is a diagram showing a first example, and Fig. 7(b) is a diagram showing a second example.

As shown in FIG. 7(a), the light emitted by the LED 131c passes through the light incident end surface 161ci and enters the narrow-angle light-guiding member 161c. After being guided through the narrow-angle light-guiding member 161c, the light exits through the light exit end surface 161co.

The irradiation light 30c indicated by the dashed line represents the light guided within the narrow-angle light-guiding member 161c. The irradiation light 30c emitted from the light-emitting end surface 161co irradiates the narrow-angle irradiated area 41c on the irradiated surface 40. The irradiated surface 40 is, for example, a wall surface inside a room.

Also, as shown in FIG. 7(b), the light emitted by the LED 131f enters the narrow-angle light-guiding member 161f through the light-incident end face 161fi, is guided through the narrow-angle light-guiding member 161f, and then exits through the light-exiting end face 161fo.

The irradiation light 30f shown by the dashed line represents the light guided within the narrow-angle light-guiding member 161f. The irradiation light 30f emitted from the light-emitting end surface 161fo irradiates the narrow-angle irradiated region 41f on the irradiated surface 40.

<Example of Light Irradiation by Light Emitting Device 1>
Next, light irradiation by the light emitting device 1 will be described with reference to Fig. 8. Fig. 8 is a diagram for explaining an example of light irradiation by the light emitting device 1.

Figure 8 shows nine narrow-angle irradiated areas 41 and one wide-angle irradiated area 42 on an irradiated surface 40. The nine narrow-angle irradiated areas 41 are areas irradiated with light emitted from each of the nine narrow-angle light-guiding members 161 included in the narrow-angle light-guiding member group 16A of the narrow-angle light-guiding member array 16. In each of the twelve narrow-angle light-guiding member groups 16A, the emitted light from each of the nine narrow-angle light-guiding members 161 irradiates each narrow-angle irradiated area 41, and the twelve irradiated lights overlap at each position of the narrow-angle irradiated area 41.

A single wide-angle illuminated area 42 is an area illuminated with light emitted from each of the 36 wide-angle light-guiding members 171 included in the wide-angle light-guiding member array 17. The emitted light from each of the 36 wide-angle light-guiding members 171 illuminates a single wide-angle illuminated area 42, and the 36 illuminated lights overlap in the wide-angle illuminated area 42.

The light irradiation example shown in FIG. 8 is just one example, and the light irradiation pattern by each of the narrow-angle light-guiding member array 16 and the wide-angle light-guiding member array 17 can be appropriately selected depending on the purpose. In addition, the light emission of the multiple LEDs 131 can be individually controlled to freely change the light irradiation position, light irradiation direction, light irradiation range, etc. by the light-emitting device 1.

<Effects of Light-Emitting Device 1>
As described above, in this embodiment, the distance between the light incident end face 161i and the LED 131 is determined by the spacer 14 (determining member) provided between the light incident end face 161i of the narrow-angle light-guiding member array 16 and the mounting surface 132 on which the LED 131 (light source) is placed.

A holding portion 162 is provided that is joined to a surface that intersects with the light incident end surface 161i and holds the end portion of the narrow-angle light-guiding member 161 on the light incident end surface 161i side, and the spacer 14 includes a back surface 14b (first contact portion) that contacts the mounting surface 132 and a front surface 14a (second contact portion) that contacts the holding portion 162.

The narrow-angle light-guiding member 161 is joined to the holding portion 162, and the holding portion 162 is in contact with the surface 14a of the spacer 14. Therefore, even if the narrow-angle light-guiding member 161 expands in the light irradiation direction due to thermal expansion or the like, the movement of the light incident end surface 161i in the direction approaching the LED 131 is suppressed.

This makes it possible to suppress fluctuations in the distance between the LED 131 and the narrow-angle light-guiding member 161, and to suppress changes in the characteristics of the light emitted by the light-emitting device 1, such as the color of the light.

In addition, because the narrow-angle light-guiding member 161 contains a soft silicone resin, the thin portion on the light-incident end face 161i side is easily moved by shock, etc. If this thin portion moves, the light-guiding state of the light guided through the narrow-angle light-guiding member 161 may change. Similarly, because the wide-angle light-guiding member 171 contains a soft silicone resin, the thin portion on the light-incident end face 171i side is easily moved by shock, etc. If this thin portion moves, the light-guiding state of the light guided through the wide-angle light-guiding member 171 may change.

In this embodiment, the holding portion 162 holds the end of the narrow-angle light-guiding member 161 on the light incident end face 161i side, so that the positional fluctuation in the X, Y, and Z directions of the narrow portion of the narrow-angle light-guiding member 161 on the light incident end face 161i side can be suppressed. Similarly, the holding portion 162 holds the end of the wide-angle light-guiding member 171 on the light incident end face 171i side, so that the positional fluctuation in the X, Y, and Z directions of the narrow portion of the wide-angle light-guiding member 171 on the light incident end face 171i side can be suppressed.

In addition, in this embodiment, the narrow-angle light-guiding member 161 and the holding portion 162 contain the same material and have approximately the same linear expansion coefficient, so the deformation amounts of the narrow-angle light-guiding member 161 and the holding portion 162 due to temperature changes are approximately the same. This suppresses the shear stress applied to the joint between the narrow-angle light-guiding member 161 and the holding portion 162 due to the difference in the deformation amount between the two. Even if the narrow-angle light-guiding member 161 deforms due to temperature changes, damage such as peeling between the narrow-angle light-guiding member 161 and the holding portion 162 can be suppressed.

In this embodiment, the holding portion 162 contains a resin containing light-reflective particles, and reflects light emitted by the LED 131 that propagates in a direction in which the radiation angle of the light emitted by the LED 131 is large (±90 degrees) and guides it to the light incident end surface 161i. This allows the light propagating in that direction to be incident on the narrow-angle light-guiding member 161, and suppresses a decrease in the light incidence efficiency.

In addition, in this embodiment, the narrow-angle light-guiding member 161 has an end portion on the light-emitting end face 161o side that can expand and contract in a direction intersecting with the light-emitting end face 161o. The direction intersecting with the light-emitting end face 161o is, for example, the light irradiation direction. Therefore, when the narrow-angle light-guiding member 161 expands along the light irradiation direction due to thermal expansion or the like, the light-emitting end face 161o is more likely to move in the light irradiation direction. This makes it possible to suppress the movement of the light-incident end face 161i and suppress fluctuations in the distance between the LED 131 and the narrow-angle light-guiding member 161.

In this embodiment, the narrow-angle light-guiding member 161 has a tapered shape that becomes thinner as it approaches the light-incident end face 161i.

The narrow-angle light-guiding member 161 also includes a narrow-angle light-guiding member 161c (first light-guiding member) and a narrow-angle light-guiding member 161f (second light-guiding member) in an array plane along the light incident end face 161i, and the central axis 161fc of the narrow-angle light-guiding member 161f is inclined with respect to the central axis 161cc of the narrow-angle light-guiding member 161c.

The distance between the central axis 161cc of the narrow-angle light-guiding member 161c and the central axis 161fc of the narrow-angle light-guiding member 161f is greater on the exit side than on the entrance side.

These configurations allow the light emitted by the light-emitting device 1 to be emitted in the desired direction.

Note that, although the effects of the light-emitting device 1 have been explained using the narrow-angle light-guiding member 161 as an example, the same effects can be obtained with the wide-angle light-guiding member 171.

<Modification>
In the above-described embodiment, a narrow-angle light-guiding member array 16 in which the holding portion 162 and the narrow-angle light-guiding member 161 are joined by an adhesive member 20 is exemplified, but the joining between the holding portion 162 and the narrow-angle light-guiding member 161 is not limited to this, and various modifications are possible.

Figure 9 is a cross-sectional view illustrating an example of the bonding between a narrow-angle light-guiding member and a holding portion according to a modified example. Figure 9(a) shows a first modified example, and Figure 9(b) shows a second modified example.

In the narrow-angle light-guiding member array 16a shown in FIG. 9(a), the narrow-angle light-guiding member 161a and the holding portion 162a are joined together by injection molding them together using a two-color molding method. Here, the two-color molding method refers to a method of molding resins with different properties into a single part.

The holding portion 162a contains a silicone resin that contains light-reflective particles. On the other hand, the narrow-angle light-guiding member 161a contains a silicone resin that does not contain light-reflective particles.

The silicone resin of the holding portion 162a contains light-reflective particles, so the light transmittance of the holding portion 162a is low. On the other hand, the silicone resin of the narrow-angle light-guiding member 161a does not contain light-reflective particles, so the light transmittance is high. In this respect, the silicone resin of the narrow-angle light-guiding member 161a and the silicone resin of the holding portion 162a are resins with different characteristics.

Here, when an adhesive material is used to join the narrow-angle light-guiding member 161a and the holding portion 162a, the linear expansion coefficients of the narrow-angle light-guiding member 161a and the holding portion 162a may differ from that of the adhesive material. Therefore, when the narrow-angle light-guiding member array 16a expands or contracts due to temperature changes or the like, the narrow-angle light-guiding member 161a and the holding portion 162a may expand or contract by different amounts from the adhesive material, causing the narrow-angle light-guiding member 161a and the holding portion 162a to peel off from the adhesive material, and as a result, the narrow-angle light-guiding member 161a may peel off from the holding portion 162a.

In contrast, in the first modified example, the narrow-angle light-guiding member 161a and the holding portion 162a are integrally molded and no adhesive is used for joining them, so peeling between the narrow-angle light-guiding member 161a and the holding portion 162a can be prevented.

The effect of the holding portion 162a containing light-reflective particles is the same as that of the holding portion 162.

In the narrow-angle light-guiding member array 16b shown in FIG. 9(b), the narrow-angle light-guiding member 161b containing silicone resin and the holding portion 162b containing a metal such as aluminum or stainless steel are integrally molded by insert molding to join the two. Here, the insert molding method refers to a method in which resin is injected around a metal part inserted in a molding die, and the resin is molded integrally with the metal part.

A light emitting device can also be constructed using the narrow-angle light-guiding member array 16b produced by this type of insert molding method.

Note that in the above-mentioned modified example, a narrow-angle light-guiding member array is described, but the same applies to a wide-angle light-guiding member array.

Although the preferred embodiments have been described above in detail, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

For example, in the above-described embodiment, a light-emitting device having a narrow-angle light-guiding member array and a wide-angle light-guiding member array with different spread angles of emitted light has been exemplified, but the present invention is not limited to this. A light-emitting device may be configured using one type of light-guiding member array with the same spread angle of emitted light, or a light-emitting device may be configured using three or more types of light-guiding member arrays with different spread angles of emitted light. A light-emitting device may also be configured using multiple types of light-guiding member arrays with different light-guiding characteristics other than the spread angle of emitted light.

1 Light emitting device 10 Opening 11 Rear substrate 12 Heat dissipation member 13 LED mounting substrate 131 LED (light source)
132 Placement surface 14 Spacer (an example of a regulating member)
141 Spacer through hole 15 Holder member 151 Narrow angle through hole 152 Wide angle through hole 16 Narrow angle light guide member array (an example of a light guide member)
16A Narrow-angle light-guiding member group 161 Narrow-angle light-guiding member 161i Light incident end surface 161o Light emitting end surface 162 Holder 17 Wide-angle light-guiding member array (an example of a light-guiding member)
17A: wide-angle light-guiding member group 171; wide-angle light-guiding member 171i: light-incident end surface 171o: light-emitting end surface 18: positioning pin 19: fixing screw 2: driving circuit 20: adhesive member 21: connector 22: FPC
25 Propagating light 40 Irradiated surface 41 Narrow-angle irradiated area 42 Wide-angle irradiated area θ Tilt angles di, do Axial distance

Claims (8)

A light source that emits light;
A light guide member that guides the light;
a defining member provided between a mounting surface on which the light source is mounted and a light incident end surface of the light guiding member into which the light is incident, the defining member defining a distance between the light source and the light guiding member;
a holding portion that is joined to a surface of the light guiding member that intersects with the light incident end surface and holds an end portion of the light guiding member on the light incident end surface side,
the defining member includes a first contact portion that contacts the placement surface and a second contact portion that contacts the holding portion,
A light emitting device , comprising: a gap provided between the light source and the light incident end surface of the light guiding member . The light-emitting device according to claim 1, wherein the light-guiding member and the holding part contain the same material. The light-emitting device according to claim 1 or 2, wherein the holding portion includes a resin containing light-reflective particles. The light-emitting device according to any one of claims 1 to 3, wherein the light-guiding member and the holding portion are integrally formed. The light-emitting device according to any one of claims 1 to 4, wherein the end of the light-guiding member on the side of the light-emitting end face from which the light is emitted is expandable in a direction intersecting the light-emitting end face. The light emitting device according to claim 1 , wherein the light guiding member has a tapered shape that becomes thinner as it approaches the light incident end surface. the light guide member includes a first light guide member and a second light guide member in a plane along the light incident end surface,
The light emitting device according to claim 1 , wherein a central axis of the first light guiding member is inclined with respect to a central axis of the second light guiding member. The light emitting device according to claim 7, wherein the axial distance between the central axis of the first light guiding member and the central axis of the second light guiding member is greater on the exit side than on the entrance side.

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