JP2005310693A - Louver for lighting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a louver for lighting easy to manufacture and of low cost, with illumination efficiency heightened by converting all light source light irradiated into light of an angle free from glare. <P>SOLUTION: A light-shielding plate is formed of a transparent material so as to heighten illumination efficiency and to avoid absorption of light, and the directions of light beam is converted by refraction and total reflection of light so as not to dissipate the light by scattering. Since it can be integrally molded in a sheet shape, it can be simple and manufactured at low cost. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement of a louver used for a light source such as a ceiling lighting in order to prevent glare of the light source.

In order to prevent glare from the light source, a louver is formed by covering the light source with a translucent cover to scatter and soften direct light, or by arranging a number of elongated light-shielding plates made of metal plates or opaque resin plates in a grid pattern The method of blocking direct light is widely used. However, the method of covering the semi-transparent cover has the disadvantage that the illumination efficiency is low because the light transmittance of the material is low and the light scattered in the direction opposite to the direction to be illuminated can be generated. In addition, in conventional louvers, if the surface of the light shielding plate is made highly reflective like a mirror, the reflected light will be dazzling and will not function as a louver. As a result, there is a disadvantage that the illumination efficiency is lowered. In order to solve these disadvantages, the following method has been proposed.
JP 05-181425 A In these methods, beads made of materials having different refractive indexes are scattered in the constituent material of the translucent cover to scatter light, or a transparent material is provided between the light shielding plate and the light shielding plate of the louver. Although it is designed to reduce the size by filling, all of these methods scatter direct light and reduce glare, so that the light is absorbed by the opaque member or dissipated by scattering, and the purpose is to improve the lighting efficiency That wasn't enough.

For this reason, the following method has been proposed. This proposal is a rectification unit using transparent glass or resin, and can rectify the traveling direction of light rays to a limited range, so it can be applied to lighting louvers, but a transparent light shielding plate with an acute triangular cross section is closely connected in parallel. Since the louver was made, there was an inconvenience that it was difficult to manufacture from the shape surface.
Japanese Patent Application No. 2003-270574

  In view of the above-mentioned reason, the present invention is to provide an illumination louver that converts almost all of the light source light rays into light rays having an angle that does not feel dazzling, has high illumination efficiency, is easy to manufacture, and is inexpensive.

  The lighting louver of the present invention is formed with a light shielding plate made of a transparent material so as not to absorb light rays in order to increase the illumination efficiency. The said subject is solved by changing the direction of a light ray by reflection.

  Since the illumination louver of the present invention is made of a transparent material, light is not absorbed by the member, and light source light is not lost due to scattering, so almost all light source light is illuminated. It is possible to irradiate the surface, and it has the advantage that the illumination efficiency is extremely high. In addition, since the cross-sectional shape can be reduced and enlarged in a similar manner, a louver adapted to the lighting fixture and the indoor atmosphere can be easily and inexpensively formed by integral molding of resin.

  The lighting louver of the present invention is used in the middle of a light source and a surface to be illuminated, integrated with a lighting fixture, or incorporated in a ceiling of a building. A transparent material such as glass or plastic resin is suitable for the light shielding plate of the louver, and a material having high transparency and a high refractive index is desirable. In addition, if a louver is formed by assembling a plurality of light shielding plates vertically and horizontally, the louver can be formed into a single plate by injection molding or press molding, so it can be suspended not only for embedded ceiling lighting louvers. It is also suitable as a cover for indoor lighting fixtures.

  In the following description, the light from the light source is the light source light, the traveling direction is the light source angle, the light traveling in the light shielding plate is the transmitted light, the traveling direction is the transmission angle, the light reaching the illuminated surface is the illumination light, The angle is referred to as an illumination angle. A light beam passing through a gap between the light shielding plate and the light shielding plate is referred to as passing light, and an angle thereof is referred to as a passing angle. The light source light entering the light shielding plate is referred to as incident, exiting, transmitting, and illuminating the illuminated surface is referred to as illumination. Further, of the transmitted light, a light beam that is inverted by total reflection or the like and returns to the light source side is referred to as lost light, and an angle thereof is referred to as a loss angle. Further, the minimum illumination angle to be blocked is referred to as a blocking angle, the illumination light that reaches the surface to be illuminated beyond the blocking angle is referred to as a leakage ray, and the angle is referred to as a leakage angle. The angle of the light beam is expressed on the assumption that ceiling illumination is used and the axis perpendicular to the floor is 0 degrees and the horizontal direction is 180 degrees.

  In ceiling lighting or the like, it is said that it is desirable to set the blocking angle to 120 degrees or less in order not to make the light source feel dazzling. Therefore, in the following description, description will be made assuming that the blocking angle of illumination light is 120 degrees. In addition, normal light sources illuminate all directions, but light rays that illuminate in the opposite direction with respect to the illuminated surface are inverted by another method such as a reflector and travel toward the illuminated surface. Among them, the illumination louver is required to have a function of converting or blocking a light beam exceeding the cutoff angle into illumination light having a cutoff angle or less.

  FIG. 1 shows a cross section of a louver serving as a basic form for explaining the principle, and shows a case where a light source 1 is provided on a ceiling. 2 is a louver body, and 3 is a light shielding plate made of a transparent material elongated in the depth direction of the paper surface. A plurality of louvers are arranged in parallel at a predetermined interval to form a louver. Further, the front inclined surface 4 on the light source side of the light shielding plate 3 is sharpened at the front end angle α, and the rear inclined surface 5 on the illuminated surface side of the light shielding plate is also sharpened at the rear end angle β. The cross-section of is substantially a hexagonal streamline.

  The light path will be described with reference to FIG. 1. The passing light a1 having a small inclination passes through the gap 8 between the light shielding plate 3 and the light shielding plate and becomes illumination light. The light source lights a2 and a3 having a larger inclination enter the light shielding plate 3 as transmitted light and are refracted, and are transmitted after being totally reflected to become illumination light. The refraction angle of the transmitted light and the transmission angle for total reflection can be calculated from the incident angle when entering the light shielding plate 3 and the refractive index of the light shielding plate material. Further, the light source light a4 exceeding the cut-off angle is refracted from the front inclined surface 4 of the light shielding plate 3 and then transmitted across the light shielding plate and becomes illumination light after entering the adjacent light shielding plate. The tip angle α and the rear end angle β can be adjusted as fine as possible to finely adjust the direction of the light beam. However, since the thickness of the entire louver 2 is increased, the cut-off angle and the refractive index of the member are taken into account. You may choose.

  If the interval between the light shielding plates 3 is appropriately selected, the light source light having a large light source angle hits only the front slope 4 of the light shielding plate, so that these light beams do not pass through as passing light. Further, since the light source light is refracted when entering the front slope 4, the transmission angle becomes smaller than the original light source angle and can be converted into illumination light having an appropriate illumination angle equal to or smaller than the cutoff angle.

  Like the light source light a5 having a large light source angle irradiated almost in the horizontal direction, illumination light may be emitted from the rear inclined surface 5 through the second and third stages of the adjacent light shielding plates 3. That is, the light source light with a small light source angle becomes the illumination light after repeating total reflection as transmitted light or reaches the illuminated surface as the passing light, whereas the light source light with a large light source angle is the front slope of the light shielding plate 3. Since the ratio of refraction at 4 is small, the light is transmitted without undergoing total reflection only by changing the angle, and is incident on the adjacent light shielding plates one after another, reaches the rear slope 5 and is refracted and converted into illumination light.

  As described above, the front end angle α of the front inclined surface 4 and the rear end angle β of the rear inclined surface 5 play an important role for converting the light source light into illumination light having a cutoff angle or less. Further, some of the light source light is reflected on the surface of the light shielding plate 3, but most of the surface reflected light is reflected in the direction of the surface to be illuminated by the inclined front slope 4, so that it is not lost light.

  If the front end angle α and the rear end angle β are 180 degrees, that is, the front inclined surface 4 and the rear inclined surface 5 are flat and the light shielding plate 3 has a rectangular cross section as shown in FIG. In the case of the light source light b2 having a large light source angle, the light is transmitted in the same manner as in FIG. 1, but it is transmitted at the same angle even if the direction is changed by 180 degrees, and the leaked light beam exceeds the cutoff angle. It becomes. Further, a light beam that is totally reflected and inverted by the rear inclined surface 5 and becomes lost light is generated as a light beam b3.

  In addition, when the front slope 4 is flattened and only the rear slope 5 is sharpened, the illumination angle can be changed on the rear slope, but the illumination angle is larger than the original light source angle as the light beam b4 in FIG. Or the transmitted light enters the rear slope 4 of the adjacent light shielding plate like the light beam b5 and becomes a leaked light beam having a larger transmission angle. Further, when the gap 8 is widened so that it does not enter the rear slope 5 of the adjacent light shielding plate, the light source light b6 that directly enters the rear slope 5 through the gap 8 is transmitted across the rear slope 5 so as to have a larger angle. It becomes a leaking light beam.

  Conversely, when the rear slope 5 is flattened and only the front slope 4 is sharpened, the illumination angle can be changed when the light source light having a large light source angle is transmitted through the front slope 4. Like b7 and b8, the light is inverted at the rear slope 5 to become lost light, or a light beam that is largely refracted and becomes a leaked light beam during transmission is generated.

  If the length 7 of the plane 6 in FIG. 1 is set longer, the light source angle of the light source light that directly enters the rear slope 5 through the gap 8 can be reduced to a light source light having a smaller angle. Lost light can be minimized. However, the thickness of the entire louver 2 increases, making it difficult to manufacture. Therefore, it is desirable to set the length 7 of the plane 6 to the minimum necessary length. The plane 6 may be parallel on both sides, but if the surface 6 is slightly inclined in accordance with the direction of inclination of the front slope 3, the light shielding plate 3 can be easily molded, and the front slope can be helped. Even if the boundary between the front slope 4 and the plane 6 and the rear slope 5 is gently curved to form a continuous streamlined curved surface, the essential function is not lost.

  FIG. 5 shows a cross section of a practical louver using an acrylic resin with a blocking angle of 120 degrees. Like in the case of FIG. 1, a plurality of transparent light shielding plates 3 are arranged in parallel while maintaining a predetermined gap. The two cross-sectional louvers are combined by rotating 90 degrees in the depth direction of the paper so as to intersect, and the plan view is integrally formed as a louver 2 as shown in FIG. Yes. By combining the two sets of louvers in this way, not only the light source light in the horizontal direction of the paper surface described in FIG. 1 but also the light source light incident at an angle greater than the cut-off angle for the light source light in the depth direction of the paper surface is blocked. It can be converted into effective illumination light below the corner. If the number of overlapping louvers is multiple, each is rotated in equal divisions in the depth direction of the paper surface, and superimposed into a lattice shape and molded integrally, the light beam can be converted finely in more directions. It will be possible. Visually, if it is 2 sets, it becomes a square, and if it is 3 sets, it becomes a hexagonal lattice pattern louver.

  Reference numeral 9 denotes a flat plate that connects between the light shielding plate 3 and the light shielding plate, and can be easily formed by being provided at the joint of the mold. Although it helps to prevent insects and dust from entering the interior of the luminaire, it does not have a functional action as a louver, so it should be as thin as possible.

  As described above, the lighting louver of the present invention is formed by arranging a plurality of streamlined transparent light-shielding plates having a front slope and a rear slope having an acute cross section in parallel while holding a predetermined gap. Because incident light source light is converted into illumination light below the cut-off angle by refraction and total reflection, it is illuminated, so there is no light scattering or absorption as with illumination louvers and illumination covers using opaque shading plates. There are very few advantages. Further, since the structure is simpler and can be integrally molded as compared with the conventional louver, there is an advantage that it can be manufactured at low cost. In addition, since the illumination louver of the present invention is similar in shape and does not change its function even if it is reduced, the louver can be formed into an extremely thin sheet, and the entire lighting fixture can be miniaturized.

  Not only for ceiling luminaires, but also for hanging light fixtures and louvers for narrowing the illumination range of projectors. it can.

It is sectional drawing of the basic form louver for demonstrating a principle. It is explanatory drawing of a rectangular light-shielding plate. It is explanatory drawing of a pentagonal light-shielding plate. It is explanatory drawing of an inverted pentagonal light-shielding plate. It is sectional drawing of the Example of the louver for illumination. It is a top view of the louver of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Louver body 3 Light-shielding plate 4 Front slope 5 Rear slope 6 Plane 7 Plane length 8 Gap 9 Flat plate α Tip angle β Trailing end angle a1 to a5 Ray path b1 to b8 Ray path

Claims (2)

  A streamlined transparent light-shielding plate having a front slope and a rear slope with an acute cross section, and a lighting louver formed by arranging a plurality of parallel light-shielding plates while maintaining a predetermined gap. An illumination louver, which is set so as to be illuminated by being converted into illumination light having a predetermined cutoff angle or less by total reflection.   An illumination louver, wherein a plurality of sets of the illumination louvers according to claim 1 are rotated in equal divisions in the depth direction of the paper surface and overlapped in a lattice shape and formed integrally.

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