Lighting device

Abstract

To provide a lighting device capable of emitting clear light.SOLUTION: A lighting device 10 emits light in a third direction different from a first direction and a second direction in order to emit elongate light having a length along the first direction and a width along the second direction orthogonal to the first direction. The lighting device 10 comprises: a light source substrate 20 including a substrate 21, and a plurality of light sources 22 that are disposed on the substrate 21 and arranged along the first direction, and emit light along the second direction; a reflector 40 that reflects, in the third direction, light emitted from the plurality of light sources 22; a housing 50 that accommodates the plurality of light sources 22 and the reflector 40, and has an opening 51 through which light reflected by the reflector 40 is emitted; and a cover member 60 that covers the opening 51, is disposed so as to be inclined at a predetermined angle with respect to a symmetry axis of light emitted from the opening 51, transmits a part L3 of the light, and reflects another part L4 of the light.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an illumination device that provides illumination with a long projected image. [Background technology]

[0002] BACKGROUND ART Conventionally, there has been known an elongated interior lighting device in which a plurality of light sources are arranged in a row along the longitudinal direction and which is attached to a mounting surface such as a ceiling or wall of a vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-149134 Summary of the Invention [Problem to be solved by the invention]

[0004] Long lighting devices may be used, for example, to illuminate objects with a significant shape to draw attention, etc. In such cases, it is necessary to illuminate with clear light, but it is also necessary to prevent the light from being unintentionally reflected by components of the lighting device itself located in the light path, resulting in stray light being emitted.

[0005] The present disclosure has been made in consideration of the above circumstances, and has an object to provide an illumination device capable of emitting clear light. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the lighting device of the present disclosure is a lighting device that emits light in a third direction different from the first direction and the second direction, in order to illuminate a long piece of light having a length along a first direction and a width along a second direction perpendicular to the first direction, and includes: a substrate; a light source substrate having a plurality of light sources arranged on the substrate 21 along the first direction and emitting light along the second direction; a reflector that reflects the light emitted from the plurality of light sources in the third direction; a housing that houses the plurality of light sources and the reflector and has an opening through which the light reflected by the reflector is emitted; and a cover member that covers the opening and is arranged at a predetermined angle with respect to the axis of symmetry of the light emitted from the opening, and that transmits a portion of the light and reflects another portion of the light. [Effects of the Invention]

[0007] The lighting device of the present disclosure can emit clear light. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an explanatory diagram showing a rear view of a truck bed on which a lighting device according to an embodiment of the present invention is mounted on the ceiling. [Figure 2] FIG. 10 is an explanatory diagram showing an example of the arrangement of lighting devices. [Figure 3] FIG. 2 is a cross-sectional view of the lighting device taken along a vertical plane. [Figure 4] FIG. 2 is a partial cross-sectional view of the lighting device taken along a horizontal plane. [Figure 5] 3A and 3B are diagrams illustrating the illumination range of the lighting device when viewed from the front and rear directions and the left and right directions. [Figure 6] FIG. 2 is a cross-sectional view of the lighting device taken along a vertical plane. [Figure 7] FIG. 2 is a partial cross-sectional view of the lighting device taken along a horizontal plane. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the lighting device of the present disclosure will be described with reference to the accompanying drawings. The lighting device of the present disclosure is arranged on a ceiling or wall surface and illuminates an illumination target with a long (linear) projected image. The lighting device can be arranged and used on the ceiling of a vehicle bed such as a truck, or on the ceiling of a building. In this embodiment, an example will be described in which the lighting device of the present disclosure is attached to the ceiling of a truck bed, and a long (linear) projected image is illuminated on the floor and wall surface to alert workers to prevent them from falling from the truck bed when the rear door is open.

[0010] [First embodiment] FIG. 1 is an explanatory diagram showing a rear view of a bed 2 of a truck 1 on which a lighting device 10 according to this embodiment is mounted on a ceiling 3. As shown in FIG. FIG. 2 is an explanatory diagram showing an example of the arrangement of the lighting device 10. As shown in FIG. FIG. 3 is a cross-sectional view of the lighting device 10 taken along a vertical plane. FIG. 4 is a partial cross-sectional view of the lighting device 10 taken along a horizontal plane. FIG. 5 is a diagram illustrating illumination ranges 12 and 13 of the illumination device 10 when viewed from the front-rear direction and the left-right direction.

[0011] In the following explanation, "front," "rear," "up," "down," "right," and "left" follow the definitions of "Fr.", "Re.", "To.", "Bo.", "R," and "L" in Figures 1 to 7. A horizontal plane is a plane that follows the front-to-back, left-to-right, and vertical directions.

[0012] 1 and 2, the lighting device 10 is disposed in a ceiling 3 in a loading platform 2 of a truck 1, which is surrounded on six sides, so that the ceiling 3 and a cover member 60 (described later) are flush with each other, or is attached to the ceiling 3. The lighting device 10 has a light source substrate 20, an optical member 30, a reflecting mirror 40, a housing 50, and a cover member 60.

[0013] The light source board 20 has a board 21, which is a well-known circuit board, a plurality of light sources 22, and a low-reflection portion 23. The plurality of light sources 22 are arranged at equal intervals on one board 21 along the left-right direction (first direction), as shown in FIG. 4, for example. The plurality of light sources 22 emit light L1 (a conceptual illumination range is indicated by a dotted line in the figure) toward the rear along the front-rear direction (second direction perpendicular to the first direction). The plurality of light sources 22 are, for example, three LEDs (Light-Emitting Diodes), and may be LEDs capable of emitting monochromatic light or three-color LEDs capable of emitting light of each color.

[0014] The low-reflection portion 23 is a region on the substrate 21 where the reflectance of light incident on the substrate 21 is lower than that of other regions on the substrate 21. The low-reflection portion 23 may be any material that can absorb light, such as black paint applied to the surface, ink, nonwoven fabric, vinyl tape, or silk screen printing. The low-reflection portion 23 is a region around the light source 22 into which reflected light L4 of the light incident on the cover member 60 is incident, and specifically, is arranged around the lower part of the light source 22 on the same surface as the surface on which the light source 22 is arranged.

[0015] The optical member 30 is made of a transparent resin such as polycarbonate. The optical member 30 receives light L1 emitted from the plurality of light sources 22, shapes the light into a desired light, and emits the formed light L2 to the reflecting mirror 40. The optical member 30 has an incident surface 31 and an exit surface 32 for the light L1 from each light source 22.

[0016] The shape of the optical member 30 is determined so as to convert the light L1 from the light source 22 into light corresponding to the length and width of the projected image 11 (elongated light). That is, the shape of the horizontal cross section (surface consisting of the front, back, left, and right directions) of the optical member 30 in FIG. 4 is determined by the curvatures of the incident surface 31 and the exit surface 32 so that the light L1 from the light source 22 is diffused in the left and right directions. The shape of the vertical cross section (surface consisting of the front, back, top, bottom) of the optical member 30 in FIG. 3 is determined according to the shape (width) of the projected image 11 illuminated on the illumination target. For example, as shown in FIG. 4, the incident surface 31 has a concave shape that matches the side shape of a semi-cylinder having a central axis along the up-down direction. As shown in FIGS. 3 and 4, the exit surface 32 has a convex shape consisting of a toroidal surface with different radii of curvature in the horizontal and vertical cross sections.

[0017] The reflecting mirror 40 is a plane mirror formed, for example, by depositing aluminum on a glass plate, and has a flat reflective surface. The reflecting mirror 40 reflects light L2 emitted from the multiple light sources 22 and further formed and emitted by the optical member 30 downward along the vertical direction (a third direction different from the first direction and the second direction and substantially perpendicular to both directions). Note that Fig. 4 shows the reflecting mirror 40 as viewed from above.

[0018] The housing 50 is a box-like member that has a shape corresponding to the shapes and arrangement of the multiple light sources 22 (light source substrate 20), the optical member 30, and the reflecting mirror 40, and houses these items. The housing 50 is made of a material (e.g., aluminum) that has excellent heat dissipation properties against the heat of the light sources 22. The housing 50 has an opening 51 on the surface facing downward. The opening 51 allows the light L3 reflected by the reflecting mirror 40 to be emitted to the illumination target.

[0019] The cover member 60 is made of, for example, a substantially transparent polycarbonate sheet, is formed into a substantially flat shape, and covers the opening 51 of the housing 50. The cover member 60 prevents dust and other particles from entering the housing 50. The cover member 60 is disposed at a predetermined angle with respect to the axis of symmetry (optical axis) of light L3 emitted from the opening 51. For example, as shown in FIG. 3, when light L3 is emitted in the same direction as the up-down direction, the cover member 60 is disposed with the front side lower than the rear side, so that it is disposed at an angle with respect to light L3. As a result, the cover member 60 transmits a portion of the incident light (main light) as light L3. From the viewpoint of obtaining a clear projection image 11, it is preferable that the cover member 60 transmits the light L3 emitted from the opening 51 without diffusing it. Furthermore, the cover member 60 reflects the remaining portion of the light (light less than the main light) as light L4. The predetermined angle at which the cover member 60 is tilted is set to an angle at which the light L4 reflected by the cover member 60 and then by the reflecting mirror 40 is incident on the low-reflection portion 23. In particular, the cover member 60 is set so that the light source 22 is not irradiated with the light L4.

[0020] In this lighting device 10, light L1 from the multiple light sources 22 is diffused and formed by the optical member 30 in accordance with the projected image 11, and is then reflected by the reflecting mirror 40 toward the target to be illuminated, thereby illuminating the target with the projected image 11 corresponding to the light L3. In other words, the lighting device 10 can form a long projected image 11 by using a small number of light sources 22 and optical member 30 in an optimal manner.

[0021] Specifically, the lighting device 10 emits downward an elongated light beam L3 having a length in the left-right direction and a width in the front-to-rear direction, as shown in Fig. 5. This allows the lighting device 10 to illuminate a projected image 11 made up of an illumination range 12 that is emitted (extends) over a wide range in the left-to-right direction toward the illumination target 9, and an illumination range 13 that is emitted over a predetermined width in the front-to-rear direction.

[0022] When the lighting device 10 is mounted on the bed 2 of the truck 1, as shown in Fig. 1, a projected image 11 is projected and illuminated at any timing onto the floor 5 and left and right wall surfaces 6 near the area where cargo is loaded and unloaded on the truck 1 (the area just before the boundary between the bed 2 and the outside of the vehicle). For example, by turning on the lighting device 10 in red at a timing when it is necessary to alert a worker working in the bed 2 with the rear door (not shown) open to prevent them from falling, the projected image 11 can form a line at the required timing without adding (permanently installing) a line to the floor 5 or wall surfaces 6 of the truck 1 themselves to alert them to the risk of falling. In other words, the lighting device 10 can emit light L3 in a meaningful shape to alert them to the risk of falling.

[0023] At this time, the cover member 60 is placed in the opening 51 at a tilt angle set with respect to the axis of symmetry of the light L3 of the cover member 60 so that the light L4 that is incident on the cover member 60 and reflected is directed toward the low-reflection portion 23. By controlling the reflection direction of the reflected light L4 of the light that is incident on the cover member 60 and directing it toward the low-reflection portion 23, it is possible to suppress re-reflection at the low-reflection portion 23 and suitably reduce stray light due to the light L4 reflected on the substrate 21. It is also possible to prevent deterioration of the light source 22 due to the light L4.

[0024] Furthermore, in the lighting device 10, the light L1 from the light source 22 passes through the optical member 30 and is then reflected downward by the reflecting mirror 40. This allows the vertical dimension to be smaller than when the light source 22 and the optical member 30 are arranged in the vertical direction and the light L1 from the light source 22 is emitted directly downward. Therefore, the lighting device 10 in this embodiment can be made smaller and at a lower cost.

[0025] Furthermore, the lighting device 10 forms and emits light L1 from the light source 22 using the optical member 30 described above. The lighting device 10 can also control the reflection direction of unintentionally reflected light to effectively suppress stray light. This allows the projection image 11 to be clearly formed as a long, linear image. Therefore, the lighting device 10 can effectively form a boundary line to alert the user to prevent falling from the bed 2 of the truck 1, as in the example of this embodiment, and can clearly be recognized by the user.

[0026] Furthermore, as a result of the miniaturization of the lighting device 10, it becomes possible to embed the lighting device 10 in the ceiling 3 of the truck 1 as shown in FIG. 2, thereby improving the degree of freedom in placement.

[0027] [Second embodiment] FIG. 6 is a cross-sectional view of the lighting device 110 taken along a vertical plane.

[0028] FIG. 7 is a partial cross-sectional view of the lighting device 110 taken along a horizontal plane.

[0029] In the lighting device 110 of the second embodiment, the same components and parts as those of the lighting device 10 of the first embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0030] The lighting device 110 has a light source substrate 20, an aperture plate 130, a reflector 140, a housing 50, and a cover member 60. The light source substrate 20, the housing 50, and the cover member 60 have substantially the same configuration as the lighting device 10, and therefore detailed description thereof will be omitted.

[0031] The aperture plate 130 is disposed between the light source 22 and the reflecting mirror 140, and is made of a thin light-blocking plate such as black ABS. The aperture plate 130 has a plurality of apertures 131 corresponding to the number and positions of the light sources 22. The apertures 131 allow some of the light L1 from the plurality of light sources 22 to pass through toward the reflecting mirror 140, and block the remaining part of the light L1. The shape of the apertures 131 can be selected as appropriate, such as a circle, an ellipse, a rectangle, a slit-like slot, or the like.

[0032] The reflecting mirror 140 is a curved mirror with a concave reflective surface, formed by, for example, depositing aluminum on polycarbonate. The reflecting mirror 140 shapes the light L2 emitted from each opening 131 into light corresponding to the length and width of the projected image 11 (elongated light) and reflects it downward. Note that Fig. 7 shows the reflecting mirror 140 viewed from above.

[0033] Specifically, reflecting mirror 140 has a focal point that coincides with the center point of light source 22 in a vertical cross section passing through the center of each light source 22. As a result, light L2 incident on reflecting mirror 140 becomes approximately parallel reflected light L3. Furthermore, reflecting mirror 140 does not have a curvature with respect to light L2 emitted from light source 22 (aperture plate 130) in a horizontal cross section. As a result, light L2 incident on reflecting mirror 140 is reflected directly according to the angle of incidence. Light L3 reflected by reflecting mirror 140 is emitted downward from opening 51, similar to lighting device 10, and illuminates the illumination target with projected image 11.

[0034] At this time, the cover member 60 is placed in the opening 51 at a tilt angle set with respect to the axis of symmetry of the light of the cover member 60 so that the light L4 that is incident on the cover member 60 and reflected is directed toward the low-reflection portion 23. By controlling the reflection direction of the reflected light L4 out of the light that is incident on the cover member 60 and directing it toward the low-reflection portion 23, it is possible to suppress re-reflection at the low-reflection portion 23 and suitably reduce stray light due to the light L4 reflected on the substrate 21. It is also possible to prevent deterioration of the light source 22 due to the light L4.

[0035] Because the illumination device 110 forms the projected image 11 using the aperture plate 130 and the reflector 140, it is possible to reduce at least the dimension in the front-to-rear direction compared to the illumination device 10 of the first embodiment, which forms the projected image 11 using the optical member 30. As a result, the dimension in the front-to-rear direction of the housing 50 of the illumination device 110 can be made smaller than the dimension in the front-to-rear direction of the housing 50 of the illumination device 10, thereby achieving even greater miniaturization.

[0036] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0037] For example, although the third direction (direction of the optical axis) in which lighting device 10 emits light is downward, this is not limiting, and the optical axis may be inclined with respect to the vertical direction. Furthermore, as long as the emission direction of lighting device 10 differs from the emission direction of light source 22, reflecting mirror 40 of lighting device 10 may be a curved mirror. Furthermore, cover member 60 may be arranged with the rear side positioned lower than the front side, so that it is inclined with respect to light L3, and accordingly low-reflectivity portion 23 may be arranged around the upper part of light source 22. [Explanation of symbols]

[0038] 1 truck (vehicle) 2 Cargo bed 3. Ceiling 5 beds 6 Left and right walls (walls) 10, 110 Lighting equipment 11 Projection image L1, L2, L3, L4 light 20 Light source board 21 PCB 22 Light source 23 Low reflection section 30 Optical Components 31 Incidence plane 32 Exit surface 40, 140 reflector 50 cabinets 51 Aperture 60 Cover member 130 Aperture plate 131 Aperture

Claims

1. An illumination device that emits light in a third direction different from the first direction and the second direction to illuminate an elongated light having a length along a first direction and a width along a second direction perpendicular to the first direction, a light source substrate including a substrate and a plurality of light sources arranged on the substrate along the first direction and emitting light along the second direction; a reflecting mirror that reflects the light emitted from the plurality of light sources in the third direction; a housing that houses the plurality of light sources and the reflecting mirror and has an opening through which the light reflected by the reflecting mirror exits; a cover member that covers the opening, is inclined at a predetermined angle with respect to the axis of symmetry of the light emitted from the opening, and transmits a portion of the light and reflects another portion of the light.

2. the light source substrate further includes a low-reflection portion, which is a region on the substrate having a lower reflectance of light incident on the substrate than other regions on the substrate; 2. The lighting device according to claim 1, wherein the predetermined angle is an angle at which the remaining portion of the light reflected by the cover member and then by the reflecting mirror is incident on the low-reflection portion.

3. an optical member that receives the light from the plurality of light sources, forms light according to the length and width of the elongated light, and emits the formed light to the reflecting mirror; The lighting device according to claim 1 , wherein the reflecting mirror is a plane mirror that reflects the formed light in the third direction.

4. an aperture plate having a plurality of apertures that transmit a portion of the light from each of the plurality of light sources toward the reflecting mirror and block the remaining portion; 2. The lighting device according to claim 1, wherein the reflecting mirror is a curved mirror that reflects incident light emitted from each of the openings of the aperture plate in the third direction, forming the light into light corresponding to the length and width of the elongated light.

5. 2. The lighting device according to claim 1, which is disposed on a ceiling of a vehicle loading platform and emits the light onto a floor and a wall of the loading platform.

Images