Elongated LED lighting device

Abstract

To prevent a bright portion of lighting and a dark portion of lighting from generating alternately in a lighting device formed by arraying a plurality of LED light-emitting devices inside an elongated housing.SOLUTION: In a lighting device 10 formed by arraying a plurality of LED light-emitting devices 13 inside an elongated housing 12, a shade 14 comprising a light diffusion member 14a and a transparent member 14b mutually continuing inside a width direction orthogonal to an arrayed direction of the light-emitting devices 13 is provided inside the housing 12. The shade 14 is in proximity to a light-emitting surfaces 13a of the LED light-emitting devices 13 and brings light emitted from the light-emitting surfaces 13a into a state of incident on the light diffusion member 14a and the transparent member 14b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an LED lighting device, in particular a long LED lighting device consisting of a long, narrow housing and a number of LED light-emitting elements arranged in a straight line inside the housing, and more specifically to an improvement to a lighting device for indirect lighting that uses a long lighting device in which a number of LED light-emitting elements are arranged in series at regular intervals to project light onto a wall surface. [Background technology]

[0002] Conventionally, as shown in Patent Documents 1, 2, and 3, long LED lighting devices have been known, each of which comprises a long, narrow housing (sometimes called a case or duct) and a plurality of LED light-emitting elements arranged in a row at intervals along the length of the housing. This type of lighting device is used for various lighting applications, including indirect lighting for buildings, homes, and other structures. For example, a long LED lighting device is installed horizontally along a wall near a ceiling-covered space, projecting light downward from behind a hanging screen. The LED light is then emitted approximately downward along the wall, brightly illuminating only the wall illuminated by the LED light. Another known example of indirect lighting is an outdoor LED lighting device that projects light from a long LED lighting device along the exterior wall of a building from below, providing indirect lighting by illuminating only the illuminated wall without directly exposing the light source to the human eye. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-033726 [Patent Document 2] Japanese Patent Application Publication No. 2023-000454 [Patent Document 3] Publication No. 3217460 Summary of the Invention [Problem to be solved by the invention]

[0004] In indirect lighting using these long LED lighting devices, the LED light-emitting elements are arranged in a row at intervals along the length, so bright and dark areas on the illuminated wall surface alternate at these intervals, resulting in uneven lighting brightness and making it difficult to achieve uniform brightness.

[0005] This problem will be explained below with reference to Figures 5 and 6. Figures 5 and 6 show an example of downward illumination from the ceiling, but for convenience of illustration, the ceiling surface is shown at the bottom, and the actual up-down direction is shown opposite. Therefore, to avoid misunderstanding, the actual up-down direction is written in both figures.

[0006] 5 and 6 respectively show an oblique view and a side view of a portion of a conventional lighting device 100 in which a plurality of LED light-emitting elements 20 are arranged in a row. Reference numeral 21 in the figures denotes a thin, elongated housing having a concave cross-section. In FIG. 5, a portion of a front side wall 22 of the housing 21 is shown cut away, while in FIG. 6, the entire side wall 22 is omitted, showing only a rear housing side wall 23. In this example, the bottom wall 24 of the housing 21 is attached to the ceiling surface 30 as described above.

[0007] FIG. 5 shows the relative positions of the circular light-emitting surface 20a of the LED light-emitting element 20, from which illumination light is emitted. As shown in FIG. 6, illumination light 40 emitted from this light-emitting surface 20a propagates downward, expanding to form a partial cone. Thus, when illumination light 40 travels downward to a certain point (the point indicated by the dashed-dotted line L in FIG. 6), the light from adjacent light-emitting elements 20 mixes with each other, brightening the overall illumination. The expanded light reaches the wall surface 31, brightly illuminating it. However, at positions above this point, i.e., near the light-emitting surface 20a, there are spaced apart areas where illumination light 40 does not reach directly or is very weak. Thus, bright and dark areas alternate. In FIG. 6, these dark areas are indicated by dotted areas.

[0008] In Figures 5 and 6, the LED light-emitting element 20 is shown as a so-called bullet-shaped element, and the circular light-emitting surface 20a is the surface of a condenser lens attached to the LED chip. However, even if a chip-on-board or surface-mounted LED light-emitting element is used instead of the bullet-shaped LED light-emitting element, the situation in which bright and dark areas are created is the same.

[0009] The present invention was made in consideration of the above circumstances, and aims to prevent the problem of uneven lighting, where bright and dark areas alternate, in a lighting device consisting of a plurality of LED light-emitting elements arranged in a row inside a long, narrow housing. [Means for solving the problem]

[0010] The lighting device according to the present invention comprises: a housing extending in one direction and having a concave cross-sectional shape in a plane perpendicular to the one direction; In this lighting device, a plurality of LED light-emitting elements are arranged in the housing with a distance between them and in the same direction, with their light-emitting surfaces facing the concave-shaped opening, The open portion is provided with a means consisting of a light diffusion portion and a transparent portion extending along the one direction and sequentially continuing in a width direction perpendicular to the one direction, and the light diffusion portion is attached to the housing so that it is close to the light-emitting surfaces of the plurality of LED light-emitting elements and so that a portion of the illumination light emitted from the light-emitting surfaces is diffused by the light diffusion member and the other portion of the illumination light passes through the transparent portion.

[0011] The lighting device according to the present invention comprises: For buildings having a ceiling surface and a wall surface extending downward from the ceiling surface approximately perpendicular to the ceiling surface, it is preferable to use the housing by bringing the outer surface of the housing on which the transparent part of the concave portion is located close to the wall surface, and attaching the surface behind the surface on which the multiple LED light-emitting elements are arranged to the ceiling surface.

[0012] The lighting device of the present invention can also be used upside down. That is, in a building having a floor and a wall extending upward from the floor substantially perpendicular to the floor, the outer surface of the housing on which the transparent portion of the concave portion is located can be placed close to the wall, and the surface behind the surface on which the LED light-emitting elements are arranged can be attached to the floor.

[0013] In the lighting device according to the present invention, the LED light emitting element preferably comprises the LED chip and a condenser lens that condenses light emitted from the LED chip and emits the light outside the element. [Effects of the Invention]

[0014] According to the lighting device of the present invention having the above-mentioned configuration, a means consisting of a light diffusion section and a transparent section as described above is attached to the housing, so that the illumination light emitted from the light-emitting surfaces of the multiple LED light-emitting elements passes through the transparent section, ensuring a sufficient amount of illumination light, while part of the illumination light is diffused by the light diffusion section and becomes omnidirectional, and becomes illumination light that is mixed with the light that passed through the transparent member, thereby preventing the problem of uneven illumination described above. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a partial cross-sectional front view showing an illumination device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view showing the vicinity of an end portion of the lighting device of FIG. 1; [Figure 3] FIG. 2 is a perspective view showing an LED light emitting element used in the lighting device of FIG. 1. [Figure 4] Schematic diagram illustrating the action of the lighting device of FIG. 1. [Figure 5] FIG. 1 is a partially cutaway perspective view showing a conventional lighting device. [Figure 6] Schematic diagram illustrating the problems with conventional lighting devices DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 respectively show a front view (partial cross section) and a perspective view of the main components of a lighting device 10 according to one embodiment of the present invention. FIG. 1 shows the lighting device 10 attached to a ceiling surface 30 during use, and also shows a wall surface 31 extending downward from the ceiling surface 30, a floor surface 32 against which the wall surface 31 abuts, and a privacy wall 33 for indirect lighting. FIG. 2 shows the lighting device 10 alone, with the vicinity of the end surface opposite the end surface of the lighting device shown in FIG. 1 shown upside down. As with the previously described FIGS. 5 and 6, these figures show the actual up-down direction during use.

[0017] The lighting device 10 includes an elongated housing 12 extending in one direction (perpendicular to the display surface in FIG. 1 ) and having a concave cross-section within the display surface. The housing 12 also includes a plurality of LED light-emitting elements 13 spaced apart in a line. The LED light-emitting elements 13 are aligned with a distance between them, with their light-emitting surfaces 13a facing the open end of the concave shape. The housing 12 has end caps on both ends of its length, but these are omitted in FIGS. 1 and 2 . Each LED light-emitting element 13 is, for example, bullet-shaped. As shown in detail in FIG. 3 , each LED light-emitting element 13 includes a roughly cylindrical holder 13b, a conical condenser lens 13c disposed within the holder, an LED chip 13d positioned near the apex of the cone of the condenser lens 13c, and a synthetic resin filter 13e that closes the opening of the holder 13b. Therefore, the light-emitting surface 13a is the outer surface of the filter 13e. More specifically, a cylindrical depression coaxial with the cone is provided at the apex of the condenser lens 13c as the entrance surface of the condenser lens 13c.

[0018] The filter 13e has a pair of protrusions 13f, 13f that fit into a pair of horizontal slits 13h, 13h spaced 180° apart on the cylindrical wall surface of the holder 13b, and notches 13g, 13g that engage with a pair of hooks 13i, 13i located 90° apart from the slits 13h, 13h of the holder 13b, so that the filter 13e can be attached to the holder.

[0019] Each LED light emitting element 13 is held by a plate-shaped holding member 17 with fasteners 16 at four locations around the circumference of the holder 13b. The multiple holders 13b are held by the holding member 17 at intervals in the longitudinal direction of the housing, and this holding member 17 is fixed to the housing 12. In this way, inside the housing 12, the multiple LED light emitting elements 13 are arranged in a row at intervals in the longitudinal direction of the housing.

[0020] Returning to Figures 1 and 2, the explanation continues. A shade 14 is attached to the housing 12, extending in the aforementioned direction, i.e., the longitudinal direction of the housing 12, thereby protecting the LED light-emitting elements 13 inside. The shade 14 is composed of a light-diffusing member 14a and a transparent member 14b, each extending in the longitudinal direction of the housing 12 and continuing with each other in the width direction perpendicular to the longitudinal direction. The shade 14 is attached to the housing 12 in close proximity to the light-emitting surfaces 13a of the LED light-emitting elements 13, so that light emitted from the light-emitting surfaces 13a is incident on the light-diffusing member 14a and the transparent member 14b. The light-diffusing member 14a and the transparent member 14b may be integrally molded in two colors, or may be separately molded and placed adjacent to each other. The transparent member 14b may also be eliminated and replaced with a space that simply allows light to pass through. A mounting member 18 is fixed to the ceiling surface 30, and a rail member 19 is lowered from the mounting member 18. The housing 12, and thus the lighting device 10, is attached to the ceiling surface 30 by sliding the rail gripping portion 12a of the housing 12, for example, from the front side to the back side in FIG.

[0021] With the shade 14 attached to the housing 12 in the above-described state, a portion of the illumination light emitted from the LED light-emitting elements 13 passes through the transparent member 14b, while the remaining illumination light enters the light-diffusing member 14a and is diffused there. Therefore, even if there is a wall 31 extending downward from the ceiling surface 30 as shown in FIG. 1 and the lighting device 10 is attached close to the wall 31, the wall 31 is irradiated with diffused light. In other words, no dark areas due to the discrete presence of multiple LED light-emitting elements 13 are created, thereby preventing the aforementioned problem of uneven illumination. Furthermore, the space below the ceiling surface 30, including the wall 31, is irradiated with not only the diffused light but also light that passes through the transparent member 14b, ensuring a sufficient overall illumination intensity.

[0022] Here, Fig. 4 schematically shows what has been explained above, with the lighting device 10 viewed from the same direction as in Fig. 1. In Fig. 4, the dotted area Q represents the light distribution curve of the light diffused by the light diffusing member 14a, and the hatched area R represents the range of the light transmitted through the transparent member 14b.

[0023] It should be noted that the "concave" cross-sectional shape of the housing 12 does not have to be a strictly angular concave shape; it could be, for example, a U-shape, or any other shape in which one of the four sides is open.

[0024] Furthermore, although the lighting device 10 of the embodiment shown above is a ceiling-mounted type that illuminates the space generally below it, the lighting device of the present invention can also be attached to, for example, a floor surface and used to illuminate the space generally above the installation position. Specifically, referring to Figure 1, it can also be attached to a wall surface 31 extending upward from a floor surface 32 and used to illuminate the space generally above the installation position. [Explanation of symbols]

[0025] 10. Lighting equipment 12 Housing 12a Housing rail grip 13 LED light emitting element 13a Light-emitting surface of LED light-emitting element 13e filter 14 Saed 14a Light diffusion member for shade 14b Transparent part of the shade 18 Mounting material 19 Rail components 30 Ceiling surface 31 Wall 32 Floor

Claims

1. a housing extending in one direction and having a concave cross-sectional shape in a plane perpendicular to the one direction; In this lighting device, a plurality of LED light-emitting elements are arranged in the housing with a distance between them and in the same direction, with their light-emitting surfaces facing the concave-shaped opening, a light diffusing means for diffusing light emitted from the light emitting surfaces of the LED light-emitting elements and a transparent means for diffusing the light emitted from the light emitting surfaces of the LED light-emitting elements; a light diffusing means for diffusing the light emitted from the light emitting surfaces of the LED light-emitting elements; and a light diffusing means for diffusing the light emitted from the light emitting surfaces of the LED light-emitting elements.

2. The lighting device described in claim 1 is used in a building having a ceiling surface and a wall surface extending downward from the ceiling surface approximately perpendicular to the ceiling surface, with the outer surface of the housing on which the transparent part of the concave portion is located close to the wall surface, and the surface behind the surface on which the multiple LED light-emitting elements are arranged attached to the ceiling surface.

3. 2. The lighting device according to claim 1, wherein the lighting device is used in a building having a floor and a wall extending upward from the floor, generally perpendicular to the floor, with the outer surface of the housing on which the transparent portion of the concave portion is located close to the wall, and the surface behind the surface on which the plurality of LED light-emitting elements are arranged attached to the floor.

4. 4. The lighting device according to claim 1, wherein the LED light-emitting element comprises an LED chip and a condenser lens that condenses light emitted from the LED chip and emits the light outside the element.

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