lighting fixtures

Abstract

To provide a lighting fixture capable of suppressing leakage light from a plurality of prisms of a light guide body.SOLUTION: A lighting fixture 1 includes: a light emitting module 21; and a columnar or tabular light guide body 30 which has an incident surface 31 where light enters, and an opposing surface 33 for emitting the light which has entered from an emission surface 32, and in which a plurality of prisms 34 is formed for emitting light from the emission surface 32. On the opposing surface 33, the plurality of prisms 34 is formed having a first surface 34a inclined with respect to the optical axis direction of the light emitted by the light emitting module 21, and a second surface 34b opposing to the first surface 34a. In the case of viewing a cross section in which the light guide body 30 is cut at a flat surface which is orthogonal to the opposing surface 33 and which is in parallel with the optical axis direction, a first angle of the first surface 34a with respect to the optical axis direction is defined as θ1, a second angle of the second surface 34b with respect to the optical axis direction is defined as θ2, a distance of adjacent two prisms 34 out of the plurality of prisms 34 is defined as L1, and a width along the optical axis of the plurality of prisms 34 is defined as L2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to lighting fixtures. [Background technology]

[0002] Patent Document 1 discloses a surface light source device including a light source and a light guide plate having an exit surface that receives light emitted from the light source through an end surface and exits the light incident from the end surface. A plurality of prisms with different apex angles are provided on the reflecting surface opposite to the exit surface so as to extend in a direction perpendicular to the end surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-85671 Summary of the Invention [Problem to be solved by the invention]

[0004] In the lighting fixtures using the surface light source device of the above-mentioned prior art, light emitted from a light source is incident on an incident surface, which is an end face, and the light that has entered the incident surface is reflected by multiple prisms formed on the light extraction surface as a reflective surface, and the light is emitted from the exit surface. In this case, simply forming multiple prisms results in a large amount of light leakage from the reflective surface. Therefore, it is necessary to suppress light leakage from the light extraction surface.

[0005] Therefore, an object of the present disclosure is to provide a lighting device that can suppress leakage of light from a plurality of prisms of a light guide. [Means for solving the problem]

[0006] To achieve the above object, a lighting fixture according to one aspect of the present disclosure includes a light source, an incident surface on which light emitted from the light source is incident, and a light extraction surface for extracting the light incident from the incident surface from an emission surface, and includes a columnar or plate-like light guide body on which a plurality of prisms for emitting light from the emission surface are formed. On the light extraction surface, the plurality of prisms having a first surface inclined with respect to the optical axis direction of the light emitted by the light source and a second surface facing the first surface are formed. each of the plurality of prisms is configured with the first surface and the second surface by the first surface and the second surface being directly or substantially connected to each other; When a cross-section of the light guide body cut by a plane orthogonal to the light extraction surface and parallel to the optical axis direction is viewed, a first angle of the first surface with respect to the optical axis direction is θ1, a second angle of the second surface with respect to the optical axis direction is θ2, a distance that is the width of each opening of the plurality of prisms is L1, and among the plurality of prisms, the law of nature if the width of two adjacent prisms is L2, the following formulas (1) to (3) hold. 0 < L2 ≦ 0.5 × L1 Formula (1) 25° ≦ θ1 ≦ 58° Formula (2) 0 < θ1 + 10° < θ2 ≦ 90° Formula (3) The width L2 is 1 / 6 or less of the distance L1 The light guide is supported by a reflector, and emits a first light emitted from the light source without passing through the reflector that supports the light guide, and a second light passing through the reflector, and the first light and the second light have different colors. .

Advantages of the Invention

[0007] The lighting fixture according to the present disclosure can suppress leakage light from a plurality of prisms of the light guide body.

Brief Description of the Drawings

[0008] [Figure 1] FIG. 1 is a perspective view illustrating a lighting fixture according to Embodiment 1. [Figure 2] FIG. 2 is a cross-sectional view illustrating a lighting fixture according to Embodiment 1 and a partially enlarged cross-sectional view showing prisms of a light guide body. [Figure 3] FIG. 3 is a partially enlarged cross-sectional view showing prisms of a light guide body of a lighting fixture according to Embodiment 1 in more detail. [Figure 4]FIG. 4 is a diagram showing the relationship between the prism spacing (mm) and the output efficiency (%) of light emitted from the prism when the second angle θ2 is changed relative to the first angle θ1. [Figure 5] FIG. 5 shows the light distribution curve of light emitted from the light guide when the width L2 is changed relative to the distance L1 when the first angle θ1 is 54° and the second angle θ2 is also 54°. [Figure 6A] FIG. 6A shows the light distribution curve of light emitted from the light guide when the width L2 is changed relative to the distance L1 when the first angle θ1 is 54° and the second angle θ2 is 90°. [Figure 6B] FIG. 6B shows a different light distribution curve of light emitted from the light guide from that shown in FIG. 6A when the width L2 is changed relative to the distance L1 when the first angle θ1 is 54° and the second angle θ2 is 90°. [Figure 7] FIG. 7 is a side view illustrating an illumination device according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view illustrating the lighting fixture taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a perspective view illustrating an example of a lighting device according to the second embodiment in a lit state. [Figure 10] FIG. 10 is a cross-sectional view illustrating an example of an optical path of light emitted by the lighting device according to the third embodiment. [Figure 11] FIG. 11 is a perspective view illustrating an illumination device according to another modification. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components not recited in independent claims will be described as optional components.

[0010] It should be noted that the drawings are schematic diagrams and are not necessarily strict illustrations. In addition, in the drawings, substantially the same components are denoted by the same reference numerals, and redundant explanations will be omitted or simplified.

[0011] Furthermore, in the following embodiments, expressions such as "approximately parallel" are used. For example, "approximately parallel" does not only mean "parallel," but also means "substantially parallel," that is, including an error of, for example, a few percent. Furthermore, "approximately parallel" means "parallel" within the range in which the effects of the present disclosure can be achieved. The same applies to other expressions using "approximately."

[0012] In the following description, in Fig. 1, the direction parallel to the optical axis direction of the light emitted by the light-emitting module is defined as the X-axis direction, the direction parallel to the longitudinal direction of the prism (the direction perpendicular to the optical axis direction) is defined as the Y-axis direction, and the direction perpendicular to the X-axis and Y-axis directions is defined as the Z-axis direction. The light guide side relative to the housing is defined as the positive X-axis direction, one side of the lengthwise direction of the prism of the light guide is defined as the positive Y-axis direction, and the depth direction of the prism of the light guide is defined as the positive Z-axis direction. The same applies to Fig. 2 and subsequent figures.

[0013] Hereinafter, a lighting fixture according to an embodiment of the present disclosure will be described.

[0014] (Embodiment 1) <Configuration: Lighting fixture 1> FIG. 1 is a perspective view illustrating a lighting device 1 according to the first embodiment.

[0015] As shown in FIG. 1 , the lighting fixture 1 is a lighting fixture that uses a columnar or plate-shaped light guide 30, and is installed on a building material such as a ceiling or a wall. The lighting fixture 1 of this embodiment may also be placed on a table such as a desk. The lighting fixture 1 can illuminate a space by irradiating light onto the surroundings. The lighting fixture 1 of this embodiment illuminates the surroundings by mainly emitting light in a direction intersecting the length direction of the light guide 30. The lighting fixture 1 of this embodiment is an edge-light type light guide 30.

[0016] FIG. 2 is a cross-sectional view illustrating the lighting device 1 according to the first embodiment and a partially enlarged cross-sectional view showing the prism 34 of the light guide 30. As shown in FIG.

[0017] As shown in FIG. 2, the lighting device 1 includes a housing 10, a light-emitting module 21, a light guide 30, and a power supply circuit 40.

[0018] [Case 10] The housing 10 is a container that is long in the Y-axis direction, and houses the light guide 30, the light emitting module 21, and the power supply circuit 40. With the light emitting module 21 and the light guide 30 housed in it, the housing 10 holds the light emitting module 21 and the light guide 30 in a position where light emitted by the light emitting module 21 is incident on the light guide 30 and where light is emitted from the emission surface 32 of the light guide 30.

[0019] The housing 10 is made of a metal material such as aluminum, and therefore has light-blocking properties. The housing 10 may also be made of a material such as resin.

[0020] The housing 10 has an opening at the portion on the positive X-axis direction side. The housing 10 forms a space for accommodating the end of the light guide 30 on the negative X-axis direction side through the opening, and supports the light guide 30 in a position substantially parallel to the XY plane. Specifically, the housing 10 is provided on the negative X-axis direction side of the light guide 30, and supports the light guide 30 with the emission surface 32 and the opposing surface 33 of the light guide 30 exposed.

[0021] [Light-emitting module 21] The light emitting module 21 is housed in and supported by the housing 10. The light emitting module 21 is supported in a position in which it emits light toward the light guide 30. That is, the light emitting module 21 is supported by the housing 10 in a position in which the light emitting surface of the light emitting module 21 faces the light guide 30 and the optical axis of the light emitting module 21 intersects with the light guide 30. In this embodiment, the light emitting module 21 is placed in the housing 10 so that the optical axis substantially coincides with the central axis O of the incident surface 31 of the light guide 30. Here, the optical axis is a straight line that substantially coincides with the emission direction of the main light emitted by the light emitting module 21. The light emitting module 21 is an example of a light source.

[0022] The light emitting module 21 has, for example, an SMD (Surface Mount Device) type LED (Light Emitting Diode) element. That is, the light emitting module 21 has a light emitting element that is an LED chip and a phosphor that emits fluorescence by wavelength conversion of light emitted by each of the light emitting elements. The light emitting element may be a COB (Chip On Board) type light emitting module. The light emitting element may be an example of a light source.

[0023] Each light-emitting element is an LED chip placed in a resin-molded cavity, and emits light that becomes the light emitted by the lighting fixture 1. Each light-emitting element is encapsulated in the cavity with resin containing phosphor. In other words, an SMD-type LED element is a packaged LED element in which each light-emitting element is encapsulated with this resin.

[0024] The light-emitting module 21 may be electrically connected to a power supply circuit 40 and may be supplied with power from the power supply circuit 40. The lighting device 1 may also include the power supply circuit 40. The light-emitting module 21 may be turned on and off under the control of a control unit (not shown) provided in the power supply circuit 40. The light-emitting module 21 may be controlled by a control unit (not shown) provided in the power supply circuit 40 to adjust the brightness and color of the light. For example, the light-emitting module 21 may employ a surface-mounted LED element that emits white light by combining a blue LED chip with a resin containing a yellow phosphor.

[0025] Furthermore, the light-emitting module 21 is mounted on a substrate on which a pair of electrode terminals (a positive electrode terminal and a negative electrode terminal) are formed for externally receiving DC power for emitting light from the light-emitting module 21. In this embodiment, a plurality of light-emitting modules 21 are provided and mounted on the substrate so as to be arranged at equal intervals in the Y-axis direction.

[0026] [Light guide 30] The light guide 30 is columnar or plate-shaped and has a plurality of prisms 34 formed thereon to guide the light emitted from the light-emitting module 21 and emit the light from an emission surface 32. In the present embodiment, the light guide 30 is a light-transmitting light guide plate that is substantially parallel to the XY plane. The light guide 30 is supported by the housing 10 by inserting the end of the light guide 30 on the negative X-axis side into an opening in the housing 10 so as to cover the opening. When supported by the housing 10, the central axis O of the light guide 30 in the longitudinal direction substantially coincides with the optical axis of the light-emitting module 21.

[0027] The light guide 30 has an incident surface 31 , an exit surface 32 , and an opposing surface 33 .

[0028] The incident surface 31 is a surface onto which light emitted from the plurality of light emitting modules 21 enters, and is a surface facing the plurality of light emitting modules 21. The incident surface 31 is a surface connected to an edge of the emission surface 32 and an edge of the facing surface 33, and is a side surface on the negative X-axis direction side of the light guide 30. The incident surface 31 is a plane substantially parallel to the YZ plane, and is a substantially uniform plane.

[0029] The exit surface 32 is a surface that emits light that has entered through the entrance surface 31, i.e., light that has been guided through the light guide 30, and is a light exit surface that irradiates the irradiation surface with light. For example, the exit surface 32 emits light that has been reflected by the opposing surface 33. The exit surface 32 is the surface of the light guide 30 on the positive side of the Z axis. The exit surface 32 is a plane that is approximately parallel to the XY plane and extends along the length of the light guide 30.

[0030] The opposing surface 33 is a light extraction surface for emitting the light incident from the incident surface 31. The opposing surface 33 is a surface that faces the emission surface 32, that is, the surface on the opposite side of the emission surface 32, and reflects the light guided by the light guide 30 toward the emission surface 32. The opposing surface 33 is the surface on the minus Z-axis direction side of the light guide 30. The opposing surface 33 is a surface substantially parallel to the X-Y plane.

[0031] FIG. 3 is a partial enlarged cross-sectional view showing the prism 34 of the light guide 30 of the lighting fixture 1 according to Embodiment 1 in more detail.

[0032] As shown in FIGS. 2 and 3, a plurality of prisms 34 are formed on the opposing surface 33. When looking at the cross-section of the light guide 30 cut in the Z-X plane, the opposing surface 33 is formed in a saw-tooth shape by the plurality of prisms 34.

[0033] Each of the plurality of prisms 34 has a first surface 34a that is inclined with respect to the optical axis direction of the light emitted by the light-emitting module 21, and a second surface 34b that faces the first surface 34a. The first surface 34a is an inclined surface facing the light-emitting module 21 side and intersects the optical axis direction. Also, the second surface 34b is the surface (or the opposing surface) on the opposite side of the first surface 34a in each of the plurality of prisms 34.

[0034] Each of the plurality of prisms 34 is a long groove extending along the Y-axis direction and is orthogonal to the optical axis direction. When looking at the cross-section of the light guide 30 cut by a plane orthogonal to the opposing surface 33 and parallel to the optical axis direction, let the first angle of the first surface 34a with respect to the optical axis direction be θ1, the second angle of the second surface 34b with respect to the optical axis direction be θ2, the distance (the width of the opening of the prism 34) between two adjacent prisms 34 among the plurality of prisms 34 be L_{1}, and the width along the optical axis direction of each of the plurality of prisms 34 (the width between two adjacent prisms 34) be L_{2}, then the following equations (1) to (3) hold.

[0035] 0 < L_{2} ≤ 0.5×L_{1} Equation (1) 25° ≤ θ1 ≤ 58° Equation (2) 0 < θ1 + 10° < θ2 ≤ 9° Equation (3)

[0036] <Power circuit 40> As shown in FIG. 2, the power supply circuit 40 is housed in the housing 10 and performs lighting control to turn on and off the light-emitting modules 21. The power supply circuit 40 is a lighting circuit in which multiple electronic components are mounted on a board. The power supply circuit 40 generates drive power for causing the multiple light-emitting modules 21 to emit light. For example, the power supply circuit 40 includes an AC / DC converter or the like. The power supply circuit 40 converts AC power supplied from a commercial power source into DC power and supplies the converted DC power to the light-emitting modules 21. This causes the light-emitting modules 21 to emit light.

[0037] The power supply circuit 40 is disposed vertically above the light emitting module 21. That is, the power supply circuit 40 is housed in the housing 10 and is disposed on the negative X-axis side of the light guide 30 and the light emitting module 21. The power supply circuit 40 is disposed, for example, near the construction material of the housing 10.

[0038] The power supply circuit 40 may be mounted on the surface of the board opposite to the mounting surface on which the plurality of light emitting modules 21 are mounted.

[0039] <Experimental Results> FIG. 4 is a diagram showing the relationship between the prism spacing (mm) and the output efficiency (%) of light emitted from the prism when the second angle θ2 is changed relative to the first angle θ1.

[0040] 3 and 4, the horizontal axis represents the prism spacing (mm), which is the sum of the distance L1 between two adjacent prisms and the width L2 of the prism along its optical axis, and the vertical axis represents the light output efficiency (%) of light output from the prism. In Fig. 4, the first angle θ1 was set to 54°, and the second angle θ2 was changed to 90°, 85°, 80°, 75°, 70°, 65°, and 54°. In this case, the light output efficiency was lowest when the first angle θ1 was 54° and the second angle θ2 was 90°, and the light output efficiency increased as the second angle θ2 decreased (or as the second angle θ2 approached the first angle θ1).

[0041] For this reason, the second angle θ2 is set to a value larger than the first angle θ1 and equal to or smaller than 90°.

[0042] The first angle θ1 is set to be equal to or greater than 25° and equal to or less than 58°, but if the first angle θ1 is less than 25°, the distance L1 becomes large, and the guided light is more likely to be reflected by the first surface of the prism and then reflected by the exit surface, and then exit from the first surface. If the first angle θ1 is greater than 58°, the distance L1 becomes small, but the guided light is more likely to travel straight through the prism or be reflected by the second surface, making it more difficult for the first surface to reflect it toward the exit surface.

[0043] In addition, the light distribution emitted by the light guide was measured when the first angle θ1 was 54° and the second angle θ2 was 90°, which resulted in the lowest light output rate, and when the first angle θ1 was 54° and the second angle θ2 was also 54°, which resulted in the highest light output rate.

[0044] FIG. 5 shows the light distribution curve of light emitted from the light guide when the width L2 is changed relative to the distance L1 when the first angle θ1 is 54° and the second angle θ2 is also 54°. FIG. 5a shows the light distribution curve when L1 = 300 μm and L2 = 700 μm, and FIG. 5b shows the light distribution curve when L1 = 300 μm and L2 = 50 μm. In both FIG. 5a and FIG. 5b, there is leakage light equivalent to the amount of control light. However, it was found that the smaller L2 is, the more the leakage light is suppressed.

[0045] Fig. 6A shows a light distribution curve of light emitted from a light guide when the width L2 is changed relative to the distance L1 when the first angle θ1 is 54° and the second angle θ2 is 90°. Fig. 6B shows a light distribution curve of light emitted from a light guide different from that shown in Fig. 6A when the width L2 is changed relative to the distance L1 when the first angle θ1 is 54° and the second angle θ2 is 90°.

[0046] In Fig. 6A, a is the light distribution curve when L1 = 300 (μm) and L2 = 50 (μm), in Fig. 6A, b is the light distribution curve when L1 = 300 (μm) and L2 = 200 (μm), in Fig. 6A, c is the light distribution curve when L1 = 300 (μm) and L2 = 300 (μm), in Fig. 6B, d is the light distribution curve when L1 = 300 (μm) and L2 = 700 (μm), and in Fig. 6B, e is the light distribution curve when L1 = 300 (μm) and L2 = 1700 (μm). It can be seen from a to e in Figs. 6A and 6B that the smaller the width L2, the more the leakage light is suppressed. Also, since leakage light does not appear at a in FIG. 6A but does appear at b in FIG. 6A, the width L2 is set to half or less of the distance L1 between a in FIG. 6A and b in FIG. 6A as the boundary.

[0047] For this reason, it is preferable that the width L2 in the short side direction is 1 / 6 of the distance L1 between two adjacent prisms 34.

[0048] <Operation> In this embodiment, as shown in FIGS. 2 and 3 , light emitted by the light-emitting module 21 enters the incident surface 31 and is guided through the light guide 30. The guided light enters a first prism 34 of the multiple prisms 34 on the opposing surface 33, exits from a first surface 34a, and further enters from a second surface 34b opposite the first surface 34a to be guided through the light guide 30. The guided light enters a second prism 34 adjacent to the first prism 34. The light entering the second prism 34 travels along the optical axis direction of the light-emitting module 21, so it is incident on and reflected by the first surface 34a and is guided to the exit surface 32. The light guided to the exit surface 32 exits from the exit surface 32 as control light whose light distribution has been controlled.

[0049] <Action and effect> Next, the effects of lighting device 1 according to this embodiment will be described.

[0050] As described above, the lighting fixture 1 of the present embodiment includes a light-emitting module 21, an incident surface 31 into which the light emitted by the light-emitting module 21 is incident, and an opposing surface 33 for emitting the light incident from the incident surface 31 from an exit surface 32, and includes a columnar or plate-like light guide 30 on which a plurality of prisms 34 for emitting light from the exit surface 32 are formed. On the opposing surface 33, a plurality of prisms 34 having a first surface 34a inclined with respect to the optical axis direction of the light emitted by the light-emitting module 21 and a second surface 34b facing the first surface 34a are formed. When a cross-section of the light guide 30 is viewed in a plane orthogonal to the opposing surface 33 and parallel to the optical axis direction, the first angle of the first surface 34a with respect to the optical axis direction is θ1, the second angle of the second surface 34b with respect to the optical axis direction is θ2, the distance between two adjacent prisms 34 among the plurality of prisms 34 is L1, and the width along the optical axis direction of the plurality of prisms 34 is L2, the following equations (4) to (6) hold.

[0051] 0 < L2 ≤ 0.5 × L1 Equation (4) 25° ≤ θ1 ≤ 58° Equation (5) 0 < θ1 + 10° < θ2 ≤ 90° Equation (6)

[0052] According to this, when the conditions of equations (4) to (6) are satisfied, even if the light emitted by the light-emitting module 21 is incident on the prism 34 and exits from the first surface 34a, it is likely to be guided to the second surface 34b. The light guided to the second surface 34b and guided through the light guide is likely to be reflected by the first surface 34a and guided to the exit surface 32.

[0053] Therefore, in this lighting fixture 1, it is possible to suppress the leakage light from the plurality of prisms 34 of the light guide 30.

[0054] Also, in the lighting fixture 1 of the present embodiment, the width L2 is 1 / 6 of the distance L1 between two adjacent prisms 34.

[0055] This allows the width L2 to be made smaller, thereby reducing the interval between two adjacent prisms 34. As a result, in this lighting device 1, leakage of light from the multiple prisms 34 of the light guide 30 can be further suppressed.

[0056] In the lighting device 1 of this embodiment, the first surface 34a is an inclined surface facing the light-emitting module 21. The second surface 34b is the surface of the prism 34 opposite to the first surface 34a.

[0057] This makes it easier for light guided through the light guide 30 along the optical axis direction to exit from the first surface 34a of the first prism 34 and enter the second surface 34b. This makes it easier for the light to pass through the second surface 34b of the first prism 34 and be reflected by the first surface 34a of the second prism 34 adjacent to the first prism 34. This makes it possible to more reliably suppress light leakage from the multiple prisms 34 of the light guide 30 in this lighting device 1.

[0058] In lighting device 1 of the present embodiment, each of the prisms 34 is a long groove extending in a direction perpendicular to the optical axis direction.

[0059] This allows light incident on the incident surface 31 of the light guide 30 to be efficiently guided to the exit surface 32, so that the lighting device 1 can perform the desired light distribution control and more reliably suppress leakage light from the multiple prisms 34 of the light guide 30.

[0060] (Embodiment 2) <Configuration: Lighting fixture 1a> FIG. 7 is a side view illustrating a lighting device 1a according to the second embodiment.

[0061] The lighting fixture of this embodiment differs from that of embodiment 1 in that a rectangular prism-shaped light guide 100 is used instead of a plate-shaped light guide. Unless otherwise specified, the other configurations of this embodiment are the same as those of embodiment 1, and the same components are denoted by the same reference numerals and detailed description of the configurations will be omitted.

[0062] As shown in FIG. 7, the lighting device 1a includes a light emitting module 121 and a light guide 100, as well as a reflector 150 and a wavelength control member 160 shown in FIG.

[0063] [Reflector 150] Fig. 8 is a cross-sectional view illustrating lighting device 1a taken along line VIII-VIII in Fig. 7. Fig. 8(a) is a cross-sectional view illustrating lighting device 1a before the distance from light-emitting module 121 is changed, and Fig. 8(b) is a cross-sectional view illustrating lighting device 1a after the distance from light-emitting module 121 is changed.

[0064] 7 and 8, reflector 150 is disposed at an end of light guide 100 and has a cylindrical shape that can guide light emitted by light emitting module 121 to incident surface 131. Specifically, reflector 150 has a cylindrical shape with a bottom, and accommodates wavelength control member 160 and light emitting module 121 in internal space K. Reflector 150 has an open edge on the positive Z-axis direction side at one end and a closed edge on the negative Z-axis direction side at the other end.

[0065] The inner surface of the reflector 150 is a reflective surface that reflects the light emitted by the light-emitting module 121. That is, the reflector 150 is mirror-finished so that the light emitted by the light-emitting module 121 can be efficiently incident on the light guide 100. The reflector 150 may be made of, for example, a metal such as aluminum, or a white resin.

[0066] The reflector 150 supports the light emitting module 121, which is located at the bottom, which is the edge on the negative side of the Z axis, so as to face the light guide 100. The reflector 150 also supports the light guide 100 in a position where the incident surface 131 of the light guide 100 faces the light emitting module 121. The light guide 100 is inserted into an opening 153 on the positive side of the Z axis at one end of the reflector 150, and the reflector 150 supports the light guide 100 in an upright position.

[0067] In this embodiment, a step 152 is formed on the inner surface of the reflector 150 to support the light guide 100 inserted into the opening 153. The step 152 is an annular groove that abuts against the end face of the light guide 100 on the incident surface 131 side, thereby supporting the light guide 100 in an upright position. In other words, the step 152 serves to align the incident surface 131 of the light guide 100 with the optical axis of the light-emitting module 121 and to maintain the position of the light guide 100. Furthermore, by arranging a ring-shaped spacer 45 in the step 152, the distance between the light-emitting surface of the light-emitting module 121 and the incident surface 131 of the light guide 100 can be changed.

[0068] The light guide 100 may be fixed to the reflector 150 by screws or the like attached to the periphery of the reflector 150, and the means for maintaining the position of the light guide 100 relative to the reflector 150 is not limited to this embodiment. In this case, too, the distance between the light-emitting surface of the light-emitting module 121 and the incident surface 131 of the light guide 100 can be changed by tightening the screws.

[0069] In addition, although the reflector 150 has a rectangular cylindrical shape in this embodiment, it may have a polygonal cylindrical shape, a cylindrical shape, a semi-cylindrical shape, etc. The shape of the reflector 150 may be appropriately set according to the shape of the light guide 100, i.e., the cross-sectional shape of the light guide 100 in the longitudinal direction.

[0070] [Light-emitting module 121] The light-emitting module 121 is housed in the reflector 150 and is disposed at the bottom of the reflector 150. The light-emitting module 121 is held at the bottom of the reflector 150 in a position in which it emits light toward the light guide 100. That is, the light-emitting module 121 is held by the reflector 150 in a position in which the light-emitting surface of the light-emitting module 121 faces the light guide 100 and the optical axis of the light-emitting module 121 intersects with the light guide 100. In this embodiment, the light-emitting module 121 is disposed inside the reflector 150 so that the optical axis substantially coincides with the central axis O of the reflector 150. Here, the optical axis is a straight line that substantially coincides with the emission direction of the main light emitted by the light-emitting module 121.

[0071] A portion of the first color light emitted by light emitting module 121 is incident on incident surface 131 without passing through wavelength control member 160. Another portion of the first color light emitted by light emitting module 121 is wavelength-controlled to the second color light via wavelength control member 160 and is then incident on incident surface 131.

[0072] [Wavelength control member 160] Wavelength control member 160 may be a wavelength conversion member that converts the wavelength of light emitted by light emitting module 121, thereby converting light of a first color into light of a second color. Wavelength control member 160 includes a phosphor that emits wavelength-converted light when irradiated with light, and the phosphor is dispersed and held in a binder, which is a transparent material made of ceramic such as glass, silicone resin, or the like. Wavelength control member 160 is, for example, a YAG (Yttrium Aluminum Garnet)-based phosphor, a CAZIN-based phosphor, an ESCOZIN-based phosphor, or a BAM (Ba, Mg, Al)-based phosphor, and can be appropriately selected depending on the color of light to be emitted from exit surface 132 of light guide 100.

[0073] Wavelength controlling member 160 may also be an optical thin film (color filter) using a dielectric multilayer film. Wavelength controlling member 160 absorbs a portion of the light emitted by light emitting module 121 and reflects the remaining light. Wavelength controlling member 160 can be appropriately selected depending on the color of light to be emitted from emission surface 132 of light guide 100, in order to reflect light of a predetermined wavelength among the light emitted by light emitting module 121.

[0074] Wavelength control member 160 is disposed along the inner surface of reflector 150. Specifically, wavelength control member 160 is laminated on the inner surface of reflector 150 and covers the inner surface of reflector 150. Wavelength control member 160 is disposed in the shape of a square tube within reflector 150, and forms space K between light emitting module 121 and incident surface 131, through which the light emitted from light emitting module 121 passes. As a result, wavelength control member 160 emits light of a predetermined color according to the properties of wavelength control member 160 when reflecting a portion of the light emitted from light emitting module 121.

[0075] [Light guide 100] The light guide 100 is in the shape of a column or a plate and has a plurality of prisms 134 formed thereon for guiding the light emitted from the light emitting module 121 and emitting the light from an emission surface 132. In this embodiment, the light guide 100 is a light-transmitting member having a rectangular column shape that is elongated in the Z-axis direction. The light guide 100 may also be in the shape of a polygonal column, a cylinder, a semi-cylinder, or the like.

[0076] The light guide 100 is supported by the reflector 150 by inserting the end portion on the negative Z-axis side into the opening 153 of the reflector 150 so as to cover the opening 153 of the reflector 150. When supported by the reflector 150, the central axis O of the light guide 100 in the length direction substantially coincides with the optical axis of the light-emitting module 121.

[0077] The light guide 100 has an incident surface 131 , an exit surface 132 , and an opposing surface 133 .

[0078] The incident surface 131 is a surface onto which light emitted by the light emitting module 121 enters, and is a surface opposite to the light emitting surface of the light emitting module 121. In other words, the incident surface 131 is an end surface on the negative Z-axis side of the light guide 100. The normal to the center of the incident surface 131 substantially coincides with the optical axis of the light emitting module 121.

[0079] Light of the first color and light of the second color are incident on the incident surface 131.

[0080] The first color light is light emitted by light-emitting module 121 and is incident on incident surface 131 without passing through reflector 150. The light incident on incident surface 131 without passing through reflector 150 is light emitted by light-emitting module 121 that is directly incident on incident surface 131 without being reflected by wavelength control member 160 of reflector 150. The second color light is light emitted by light-emitting module 121 and is different from the first color light that is incident on incident surface 131 via reflector 150. The second color is a color different from the first color. In other words, the wavelength of the second color light is different from the wavelength of the first color light. The light that is incident on incident surface 131 via reflector 150 is light that is emitted by light-emitting module 121 and is reflected by wavelength control member 160 of reflector 150, thereby controlling the wavelength from the first color to the second color, and then indirectly incident on incident surface 131.

[0081] The light exit surface 132 is a surface that emits light that has entered through the light entrance surface 131 , and is the surface opposite to the opposing surface 133 .

[0082] On the opposing surface 133, a plurality of prisms 134 for emitting light are formed.

[0083] The multiple prisms 134 are formed on the opposing surface 133 along the length direction of the light guide 100, and are not formed on a surface (opposing surface) on the opposite side that is line-symmetrical in the length direction (Z-axis direction) to the opposing surface 133. More specifically, the multiple prisms 134 are not formed on a surface (emission surface 132 in this embodiment) that is parallel to the opposing surface 133 and plane-symmetrical with respect to a plane that includes the central axis O.

[0084] Light incident on prisms 134 formed on opposing surface 133 is guided through prisms 134 to exit surface 132 on the opposite side, and exits from exit surface 132. Each of the plurality of prisms 134 is a cone-shaped, frustum-shaped, or long-groove-shaped convex or concave portion. In this embodiment, each of the plurality of prisms 134 is a long groove formed along the length direction of light guide 100, but may also be, for example, a conical concave portion.

[0085] A plurality of prisms 134 may also be formed on the side surface of the light guide 100 along the Z-axis direction (the surface between the emission surface 132 and the opposing surface 133).

[0086] Fig. 9 is a perspective view illustrating a lighting state of lighting fixture 1a according to embodiment 2. Fig. 9a is a perspective view illustrating a lighting state of lighting fixture 1a before the distance from light-emitting module 121 is changed, and Fig. 9b is a perspective view illustrating a lighting state of lighting fixture 1a after the distance from light-emitting module 121 is changed.

[0087] 9, the light exit surface 132 emits light of a first color from a first region R1 and emits light of a second color from a second region R2 different from the first region R1. The sizes of the first region R1 and the second region R2 vary depending on the distance between the light-emitting surface of the light-emitting module 121 and the incident surface 131. For example, if the incident surface 131 is brought closer to the light-emitting module 121, the first region R1 gradually moves in the positive direction of the Z axis, and the second region R2 also moves in the positive direction of the Z axis. On the other hand, if the incident surface 131 is moved away from the light-emitting module 121, the first region R1 gradually moves in the negative direction of the Z axis, and the second region R2 also moves in the negative direction of the Z axis.

[0088] <Operation> In this embodiment, as shown in FIGS. 8 and 9 , a wavelength conversion member having a red phosphor is used as wavelength control member 160. Wavelength control member 160 converts white light emitted by light emitting module 121 into red light. In such lighting device 1a, as shown in FIG. 9 , when light emitting module 121 emits white light, some of the white light is incident on incident surface 131 of light guide 100 without passing through wavelength control member 160, and is guided through light guide 100. Because the angle of the white light with respect to the optical axis of the light emitted by light emitting module 121 is small, the white light reaches the end of light guide 100 on the positive side of the Z axis. As a result, the white light is emitted from first region R1 of exit surface 132 of light guide 100.

[0089] Another portion of the white light is incident on wavelength control member 160, whereby it is wavelength-converted to red light, and the red light is reflected. The wavelength-converted red light then enters incident surface 131 of light guide 100 and is guided through light guide 100. Because the angle of the red light with respect to the optical axis of the light emitted from light-emitting module 121 is larger than that of the white light, the light ends up being emitted from the end of light guide 100 on the negative Z-axis side before reaching the end of light guide 100 on the positive Z-axis side. As a result, the red light is emitted from second region R2 of exit surface 132 of light guide 100.

[0090] <Action and effect> Next, the effects of lighting fixture 1a according to this embodiment will be described.

[0091] As described above, in lighting device 1a of the present embodiment, light guide 100 is columnar. The prisms 134 are formed on opposing surface 133 along the length direction of light guide 100, but are not formed on the surface that is line-symmetrical with respect to opposing surface 133 in the length direction (Z-axis direction).

[0092] This makes it possible to prevent light reflected by the plurality of prisms 134 from being reflected by the plurality of prisms 134 arranged on the opposite side. Therefore, in lighting device 1a, light reflected by the plurality of prisms 134 can be reliably emitted from light exit surface 32.

[0093] This embodiment also provides the same effects as those of the first embodiment.

[0094] (Embodiment 3) The lighting fixture 1b of this embodiment will now be described.

[0095] The present embodiment differs from the lighting fixture of embodiment 1 in that light-emitting modules 121 include first light-emitting module 121a, second light-emitting module 121b, and third light-emitting module 121c. The present embodiment also differs from the lighting fixture of embodiment 1 in that a plurality of prisms 134 are formed on both sides of light guide 101. Unless otherwise specified, the other configurations of the present embodiment are the same as those of embodiment 1, etc., and the same configurations are denoted by the same reference numerals and detailed description of the configurations will be omitted.

[0096] FIG. 10 is a cross-sectional view illustrating an example of the optical path of light emitted by lighting device 1b according to the third embodiment.

[0097] In this embodiment, as shown in FIG. 10, the reflector 150 accommodates one or more first light emitting modules 121a, one or more second light emitting modules 121b, and one or more third light emitting modules 121c.

[0098] [Light-emitting module 121] The light emitting modules 121 include one or more first light emitting modules 121a that emit light of a first color, one or more second light emitting modules 121b that emit light of a second color, and one or more third light emitting modules 121c that emit light of a third color.

[0099] Specifically, the one or more first light emitting modules 121a are arranged on or near the central axis O of the reflector 150, the one or more second light emitting modules 121b are arranged so as to surround the periphery of the one or more first light emitting modules 121a, and the one or more third light emitting modules 121c are arranged so as to surround the outer periphery of the one or more second light emitting modules 121b. In other words, the one or more second light emitting modules 121b and the one or more third light emitting modules 121c are arranged concentrically around the set of one or more first light emitting modules 121a.

[0100] The first light emitting module 121a has a first lens 121c1 that covers the cavity. The first lens 121c1 controls the light distribution so that the light emitted by the first light emitting module 121a is incident on the incident surface 131 of the light guide 101 without passing through the reflector 150. In other words, the optical axis of the light emitted by the first light emitting module 121a intersects with the incident surface 131.

[0101] The second light emitting module 121b has a second lens 121c2 that covers the cavity. The second lens 121c2 controls the light distribution so that the light emitted from the second light emitting module 121b is incident on the incident surface 131 of the light guide 101 via the reflector 150. The optical axis of the light emitted by the second light emitting module 121b intersects with the inner surface of the reflector 150.

[0102] The third light-emitting module 121c has a third lens 121c3 that covers the cavity. The third lens 121c3 controls the light distribution so that the light emitted by the third light-emitting module 121c is incident on the incident surface 131 of the light guide 101 via the reflector 150. The optical axis of the light emitted by the third light-emitting module 121c intersects with the inner surface of the reflector 150. The intersection point where the optical axis of the third color light emitted by the third light-emitting module 121c intersects with the inner surface of the reflector 150 is located closer to the light-emitting module 121 than the intersection point where the optical axis of the second color light emitted by the second light-emitting module 121b intersects with the inner surface of the reflector 150.

[0103] [Light guide 101] The light guide 101 has an incident surface 131 , one surface 141 , and another surface 142 .

[0104] The incident surface 131 is an end surface on the negative Z-axis direction side between the one surface 141 and the other surface 142 , and is a surface facing the light emitting surface of the light emitting module 121 .

[0105] One surface 141 is a surface that emits light that has entered through incident surface 131, and is the surface opposite to other surface 142. One surface 141 is a surface that extends along the Z-axis direction. In this embodiment, since light guide 101 has a quadrangular prism shape, one surface 141 is a flat surface, but it may be an arc-shaped curved surface depending on the shape of light guide 101.

[0106] The other surface 142 is a surface that emits light that has entered through the incident surface 131, and is the surface opposite to the one surface 142. The other surface 142 is a surface that extends along the Z-axis direction. In this embodiment, since the light guide 101 has a quadrangular prism shape, the other surface 142 is a flat surface, but it may be an arc-shaped curved surface depending on the shape of the light guide 101.

[0107] One surface 141 has a light extraction surface 141a on which a plurality of prisms 134 are formed, and one or more emission surfaces 141b adjacent to the light extraction surface 141a. The other surface 142 has a light extraction surface 142a formed on the surface opposite to the emission surface 141b of the one surface 141, and an emission surface 142b formed on the surface opposite to the light extraction surface 141a of the one surface 141. That is, when viewed in cross section of the light guide 101 in FIG. 10 , the light extraction surface 141a and the emission surface 142b are arranged line-symmetrically with respect to the central axis O, and the emission surface 141b and the light extraction surface 142a are arranged line-symmetrically with respect to the central axis O.

[0108] A plurality of light extraction surfaces 141a and emission surfaces 141b may be formed on one surface 141. Also, a plurality of light extraction surfaces 142a and emission surfaces 142b may be formed on the other surface 142.

[0109] The present embodiment provides the same effects as those of the first embodiment and the like.

[0110] (Other variations) Although the lighting fixture according to the present disclosure has been described above based on the first to third embodiments, the present disclosure is not limited to the first to third embodiments described above.

[0111] For example, in the lighting fixture according to the third embodiment, the reflector does not necessarily need to be provided with a wavelength converting member.

[0112] Furthermore, the light guide of the lighting fixture according to the third embodiment may be applied to the other first and second embodiments, and the light guide of the first and second embodiments may be applied to the light guide of the third embodiment.

[0113] Furthermore, in the lighting fixture 1c according to the third embodiment, as shown in Fig. 11, the plurality of prisms 134 may also be formed on all side surfaces 160 of the light guide 102 along the Z-axis direction (i.e., on the four side surfaces that are the outer peripheral surfaces in the circumferential direction of the central axis O of the light guide). Furthermore, on the side surfaces 160 of the light guide 102, the area (or width in the Z-axis direction) of the light extraction surfaces 161 on which the plurality of prisms 134 are formed increases with increasing distance from the light-emitting module 121 (reflector 150), and the area (or width in the Z-axis direction) of the emission surfaces 162 decreases. Fig. 11 is a perspective view illustrating a lighting fixture 1c according to another modified example.

[0114] Furthermore, in the lighting fixtures according to the second and third embodiments, the first color light may be light having a different color temperature from the second color light. In this case, the first color light may be light having a lower color temperature than the second color light, or light having a higher color temperature. In this case, if there is only one light source, the concentration or type of phosphor in the cavity may be made different. For example, the concentration or type of phosphor in the cavity between the light-emitting element and the reflector may be made different from the concentration or type of phosphor in the cavity between the light-guiding body and the light-emitting element.

[0115] In the lighting fixture according to the first embodiment, the prisms may be formed on the light exit surface. In this case, the prisms formed on the light exit surface may emit light from an opposite surface, which may also serve as the light exit surface, and the light exit surface on which the prisms are formed may also serve as a light extraction surface.

[0116] In addition, this disclosure also includes forms obtained by making various modifications to the above-mentioned embodiments 1 to 3 that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions of each of embodiments 1 to 3 within the scope of the present disclosure. [Explanation of symbols]

[0117] 1, 1a, 1b, 1c Lighting fixtures 21, 121a, 121b, 121c Light-emitting module (light source) 30, 100, 101, 102 Light guide 31, 131 entrance plane 32, 132 exit surface 33, 133 Opposite surface (light extraction surface) 34, 134 Prism 34a 1st page 34b 2nd side 132, 162 exit surface 161 Light extraction surface

Claims

1. A light source and a columnar or plate-shaped light guide having an incident surface into which light emitted from the light source is incident and a light extraction surface for emitting the light incident from the incident surface from an emission surface, and on which a plurality of prisms for emitting the light from the emission surface are formed, the plurality of prisms are formed on the light extraction surface, each having a first surface inclined with respect to the optical axis direction of the light emitted from the light source and a second surface facing the first surface; each of the plurality of prisms is configured with the first surface and the second surface by the first surface and the second surface being directly or substantially connected to each other; When viewing a cross section of the light guide taken along a plane perpendicular to the light extraction surface and parallel to the optical axis direction, the following formulas (1) to (3) are established, where θ1 is a first angle of the first surface with respect to the optical axis direction, θ2 is a second angle of the second surface with respect to the optical axis direction, L1 is a distance that is a width of each opening of the plurality of prisms, and L2 is a width between two adjacent prisms among the plurality of prisms: 0<L2≦0.5×L1 Formula (1) 25°≦θ1≦58° Formula (2) 0<θ1+10°<θ2≦90° Formula (3) The width L2 is equal to or less than 1 / 6 of the distance L1, The light guide is Supported by a reflector, a first light emitted from the light source without passing through a reflector supporting the light guide, and a second light passing through the reflector; The first light and the second light have different colors. Lighting fixtures.

2. the first surface is an inclined surface facing the light source side, The second surface is a surface of the prism opposite to the first surface.

10. The lighting fixture of claim 1.

3. Each of the plurality of prisms is a long groove extending in a direction perpendicular to the optical axis direction.

3. A lighting fixture according to claim 1 or 2.

4. The light guide is columnar, The plurality of prisms are formed on the light extraction surface along the length direction of the light guide, and are not formed on the surface on the opposite side of the light extraction surface that is line-symmetrical with respect to the length direction. The lighting fixture according to any one of claims 1 to 3.

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