Lighting fixture

Abstract

To provide a downlight capable of greatly suppressing both indirect glare inside a fixture and unintended internal reflection light such as a ring, at low cost.SOLUTION: A lighting fixture has a spotlight-type downlight shape, has a structure such that inside a cylindrical body of the spotlight shape, an inner cylinder is stacked in two layers, where the inside of a root side closest to a light source is made into a matte black diffusion surface, and the inside of a side closer to an end is made into a black mirror reflective surface, so that it is possible to suppress appearance of a visible light-emitting part and an unexpected light-emitting part other than a design irradiation surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lighting fixture in which the light source part is formed in a cylindrical shape, and in particular to a spotlight-shaped downlight. [Background technology]

[0002] With downlights, it is important to reduce glare at the edge where the light comes out. Recently, the desired quality of glare has been changing, and there is a trend to dislike large areas of light, even if they are acceptable according to rating indexes such as UGR (Unified Glare Rating). To cope with this, cylindrical spotlight-shaped downlights have been developed, and in cases where glare is desired, a light-shielding hood used with spotlights may be attached. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-4545 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, even if these types of hoods are used to minimize light reflection, there are few that can completely absorb light, and most have black diffusing surfaces that increase the degree of diffusion. Therefore, when light hits them, they emit a faint, even light. On the other hand, a method of preventing glare using a black mirror finish is known. In this case, strong reflected glare is caused, but it is limited to a small area, so it does not cause unpleasant glare that shines over a wide area as when a diffusing surface is used. However, because it is a reflective surface, unintended refracted light occurs, resulting in high brightness areas such as unnecessary ring-shaped light around the desired spot light. [Means for solving the problem]

[0005] The inner tube of the cylindrical spotlight is structured by stacking tubes in two stages, with the inside of the base side close to the light source being a black matte diffusing surface, and the inside of the side close to the tip being a black mirror reflective surface. Effect of the Invention

[0006] To provide a downlight that significantly suppresses both indirect glare inside a fixture and unintended internal reflected light such as a ring at an affordable price. [Brief description of the drawings]

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

[0008] Thus, there are two challenges to be overcome in designing a better downlight: avoiding glare and avoiding the generation of unnecessary ring-shaped light caused by unintended refracted light. To avoid these problems, strict optical design is required to prevent unintended refracted light, and a complete redesign is required. Therefore, it was difficult to achieve both narrow glare and an illuminated surface without light leakage.

[0009] The lighting fixture of the present invention incorporates the advantages of both of these approaches.

[0010] FIG. 1 is a diagram showing a simplified structure of a lighting fixture according to the present invention. In this embodiment, an LED is used for the light source. LED 102, which serves as the light-emitting part, is installed in base 101, and lens 103 corresponding to LED 102 is attached. Two inner cylinders are installed inside outer cylinder 104, which serves as the exterior part of the downlight, so that they are stacked in two stages. The inner surface of inner cylinder 105, which is the side closest to the light source, is a matte black diffusing surface. The inner surface of inner cylinder 106, which is the end side and farthest from the light source, is a mirror black reflective surface.

[0011] For the sake of explanation, the state of light when the inner surfaces of the cylindrical body are all diffusing surfaces and when they are all reflective surfaces will be described.

[0012] Figure 2 is a conceptual diagram of how light behaves when all the inner surfaces are diffusing surfaces. Of the light emitted by the LED, all that hits the inner surface of the cylinder is diffused by the inner surface. This allows the inside of the cylinder to emit light evenly, and the inside of the cylinder can be visually recognized as a large light-emitting surface.

[0013] FIG. 3 is a conceptual diagram of the behavior of light when all the inner surfaces are reflective surfaces. All of the light emitted by the LED that hits the inner surface of the cylinder is reflected by the inner surface. In this case, if there is a small amount of light concentrated on the mirror surface or part of the lens, the light will be concentrated and appear as a ring-shaped irradiation area as shown in the figure, and it is not realistic to completely eliminate this.

[0014] FIG. 4 is a conceptual diagram showing the behavior of light from a lighting fixture of the present invention. The portion above the dashed line is inner cylinder 105 shown in FIG. The light emitted from the LED is diffused by the inner surface of inner tube 105, which is closest to the light source, and is reflected by the inner surface of inner tube 106, which is closest to the end. At this time, the part that is diffused and becomes the light-emitting surface near the light source is limited to only the recessed part of the cylinder, so it is not directly visible. Also, since the reflecting surface is limited to the vicinity of the end, the direct light is almost homogeneous, consisting only of light in the forward direction, which is likely to be homogeneous due to the lens design, and fine diffused light from the light-emitting surface inside the cylinder mentioned above.

[0015] This structure makes it possible to simultaneously adopt the advantages of two glare countermeasure methods without having to fundamentally revise the optical design.

[0016] In the lighting fixture of this embodiment, taking into consideration ease of manufacture, the matte black diffusing surface of the inner tube 1 is finished with a low-temperature black chrome finish, the mirror black reflective surface of the inner tube 2 is finished with a glossy urethane paint. The inner diameter of the inner cylinder was designed to be 9 mm, and the length of the inner cylinder 2 was also designed to be 9 mm.

[0017] If the length of the inner tube 2 is short, it directly affects the glare angle at which the light-emitting surface is visible, so it is desirable to make it as long as possible, but it is difficult to paint a length deeper than the inner diameter with a uniform mirror finish in the general painting process. If it is the same value as the inner diameter, the angle at which the light-emitting surface is visible is 45°, so it can be said to have sufficient glare-cutting performance. [Industrial Applicability]

[0018] In this way, a downlight with high glare reduction performance can be obtained with a simple and feasible configuration. Any combination of the above components and expressions converted into devices, methods, systems, etc. are also effective as aspects of the present invention.

[0019] In addition, modifications such as changing the base to a duct rail type are possible, and the color of the inside of the tube does not have to be black, but can be a similar color, or even white, gray, silver, or another color scheme that balances the effect with the design. [Explanation of symbols]

[0020] 101 Lighting fixture base 102 LED 103 Lens 104 Outer cylinder 105 Inner tube close to the light source 106 Inner cylinder near the end

Claims

1. This lighting device has a base and a cylindrical light source unit with a built-in light source, the cylindrical light source unit having a light source on a side closer to the base, a first cylinder whose inner surface is a diffusing surface inside the cylindrical light source unit on a side closer to the light source, and a second cylinder whose inner surface is a reflective surface inside the cylindrical light source unit on an end side farther from the light source.

2. 2. The lighting device according to claim 1, wherein the inner surface of said first cylinder is a light-absorbing surface that is black in color.

3. 3. The lighting fixture of claim 1, wherein the base is a ceiling recessed type.

4. 4. A lighting fixture as claimed in any one of claims 1 to 3, wherein the inside of the first barrel is a low temperature black chrome finish.

5. 5. The lighting fixture according to claim 1, wherein the inside of the second cylinder is finished with a paint.

6. The lighting device of claim 5 , wherein the length of the second cylinder is within the inner diameter.

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