JP4711456B2 - Downlight - Google Patents

Description

  The present invention relates to a downlight, and more particularly, includes a light source, a bowl-shaped reflector that reflects light from the light source downward, and a substantially cylindrical cone disposed below the opening of the reflector. The present invention relates to a downlight structure that can be downsized without degrading performance.

  As shown in FIG. 7, for example, the conventional general downlight configuration accommodates a cup-shaped reflector 114 that opens downward in a cup-shaped cover 111 that opens downward. By arranging the lamp 112 as the light source in the light source, the light emitted from the lamp 112 can be reflected downward by the reflector 114 to irradiate the light, and the light is emitted from the opening 151 formed in the ceiling plate 150. The cover 111 is inserted into the cover 111, and the flange-shaped frame 132 formed on the open side edge of the cover 111 is attached in contact with the periphery of the opening 151. It is comprised so that it can attach in the state embedded in the figure etc. (FIG. 1 of patent document 1).

  Here, in such a downlight, when the light of the lamp 112 as a light source or the reflected light from the reflector 114 directly enters the visual field, this light is felt as an unpleasant glare. Therefore, the angle θ ′ (hereinafter referred to as “cut-off angle”) formed by the portion outside the light irradiation range (the hatched portion in FIG. 4) obstructed by the lower edge of the downlight is down. The light blocking characteristic of the light is expressed.

  Here, in the downlight described with reference to FIG. 7, the cut-off angle θ ′ is specified by the inclination of the line connecting the edge of the cover 111 and the light emitting point of the light source, and the shape of the reflector 114 The size of the light source 112 is determined depending on the size of the cover 111 and the reflector 114. Therefore, when changing this, it is necessary to review the design of the entire downlight.

  Therefore, a cylindrical cone 120 attached below the opening 114a of the reflector 114 is provided separately from the downlight body 110 formed by housing the lamp 112 and the reflector 114, which are light sources, in the cover 111 as shown in FIG. It has also been proposed to change the aforementioned cut-off angle θ ′ depending on the length of the cone 120 to be provided and attached. For example, a matte black paint is applied to the inner periphery of the cone 120 to provide a light shielding effect. The angle θ between the line L2 ′ that intersects the center line C ′ of 120 and connects the lower end opening edge 121 of the cone 120 and the inner peripheral edge 114e of the reflector 114 and the horizontal line L1 ′ that passes through the lower end edge 121 of the cone 120 Downlights designed to prevent light from being irradiated in the range of 'have also been proposed.

  Furthermore, as a downlight provided with such a cone, a cup-shaped reflector, a light source, and a socket for mounting the light source are accommodated in the cover, and the luminaire body is formed as an integral unit. There has also been proposed a downlight with a variable cut-off angle θ ′ as described above by making it easy to replace the cone with a different length by attaching a cylindrical cone to the opening edge via an adapter. (Patent Document 2).

Prior art document information of the present invention includes the following.
Japanese Patent Laid-Open No. 2003-45205 JP 2008-34185 A

  The downlight configured as described above is formed on the ceiling plate, inserted into the opening, and embedded in the ceiling. The larger the downlight, the more the opening formed in the ceiling. However, the appearance from the indoor side becomes worse because the presence of downlights installed on the ceiling is conspicuous.

  Therefore, in order to make the presence of the downlight inconspicuous, it is desirable to downsize such a downlight, in particular, downsize the downlight so that the opening formed in the ceiling can be downsized. ing.

  However, if the outer shape of the downlight is reduced, the inner diameters of the reflector and the cone described above are inevitably narrowed, and the accommodation space for the light source formed in the reflector is also narrowed.

  As a result, if the downlight is to be miniaturized, it is necessary to use a small lamp with a low wattage as a light source, and it is difficult to ensure sufficient brightness.

  In particular, when the cut-off angle θ ′ is adjusted with the above-mentioned cone, a cone baffle having a light shielding property, such as by painting the inner peripheral surface of the cone black, is used. Of the light reflected by the reflector and the light reflected by the reflector, the light incident on the cone baffle is not effectively used as illumination, and this also causes a decrease in brightness.

  On the other hand, if an attempt is made to accommodate a large lamp as a light source in the space inside the downlight body, which is narrowed due to miniaturization, the distance between the lamp and the reflector is reduced, resulting in a decrease in heat dissipation and the lamp bursting due to overheating. There is a risk of damage.

  In addition, as described above, a sufficient distance cannot be secured between the lamp and the reflector, so the light reflected by the reflector is blocked by the lamp and the brightness is lowered. As a result, the necessary brightness can be secured. Disappear.

  Therefore, in order to correct the adverse effect caused by such a narrow interval between the lamp and the reflector, the position of the lamp as the light source may be moved downward so that it is separated from the reflector.

  However, when the lamp as the light source is moved downward, the lamp approaches the indoor side, and the cut-off angle θ ′ described above is narrowed, and the light shielding performance of the downlight is lowered. If the length of the cone is extended in order to prevent this, the entire downlight is enlarged, and the brightness is lowered because the extended range of the cone increases the area covered by the cone.

  In order to reduce the loss of brightness due to the light being blocked by the cone in this way, the light incident on the inner peripheral surface of the cone can also be reduced by making the inner peripheral surface of the cone a mirror surface or painting it in white. It is also conceivable to reflect the light downward and use it for illumination.

  However, simply by setting the inner peripheral surface of the cone as a mirror surface or the like, the diffusion range of the light reflected by the cone cannot be controlled, and therefore the above-described cutoff angle θ ′ cannot be determined.

  Therefore, the present invention has been made to eliminate the drawbacks of the prior art described above, and without reflecting the position of the light source downward, and thus closer to the indoor side, the reflection of light by the reflector and the light of the cone. By controlling the light irradiation range in combination with reflection, the light from the lamp can be used effectively without causing any loss. It is an object of the present invention to provide a downlight that can ensure the safety.

In order to achieve the above object, the downlight 1 of the present invention includes a light source 12, a bowl-shaped reflector 14 that reflects light from the light source 12 downward, and the reflector 14 below the opening 14 a of the reflector 14. In a downlight with a substantially cylindrical cone arranged coaxially with 14,
The cone is formed as a cone reflector 20 having an inner peripheral surface as a reflection surface,
An inner peripheral surface of the reflector 14 is formed by a spheroidal surface obtained by rotating about the major axis of the ellipse, and the first focal point F1 of the reflector 14 is in a space surrounded by the inner peripheral surface of the reflector 14 And the second focal point F2 is disposed on the cone reflector 20,
Assuming a reference line L2 that intersects the center line C of the cone reflector 20 and connects the lower end opening edge 21 of the cone reflector 20 and the inner peripheral edge 14e of the opening of the reflector 14, the inclination angle of the reference line L2 is The reflector 14 and the cone reflector 20 are formed to have a predetermined angle θ, and the second focal point F2 of the reflector 14 overlaps with the intersection of the reference line L2 and the center line C of the cone reflector 20, or Placed below the intersection,
The light emitting point 12a of the light source 12 is disposed at the first focal point F1 of the reflector 14, and the incident light from the light emitting point 12a of the light source 12 is reflected on the inner peripheral surface of the cone reflector 20 to produce the angle θ. A rotating surface is obtained by rotating a part of a parabola that generates reflected light having a larger inclination angle.

  In the downlight 1 having the above-described configuration, the reflection of the inner peripheral surface on the opening 14a side of the reflector 14 can be more diffused than other portions (Claim 2). The inner peripheral surface of the reflector 14 on the opening 14a side may be frosted (Claim 3).

  Further, the dimple 16 may be formed on the inner peripheral surface of the reflector 14 (Claim 4), and the diameter of the dimple 16b formed in the predetermined range D on the opening 14a side of the reflector 14 is set to another portion. It may be formed smaller than the diameter of the dimples 16a formed in the above (claim 5).

  In addition, the dimples 16b formed on the opening 14a side of the reflector 14 can be randomly formed without any gaps (Claim 6).

  With the configuration of the present invention described above, according to the downlight 1 of the present invention, the following remarkable effects can be obtained.

  The reflector 14 and the cone reflector 20 are formed as described above, and the light source 12, the reflector 14 and the cone reflector 20 are arranged so as to have the above-described relationship, so that the light reflected by the inner peripheral surface of the cone reflector 20 is reflected. Also, the lower portion of the cone reflector 20 does not irradiate the range of the angle θ formed between the orthogonal line L1 with the center line C passing through the lower end of the opening of the cone reflector 20 and the reference line L2 (the hatched portion in FIG. 2). We were able to irradiate towards.

  As a result, not only the direct light from the light source 12 or the light from the light source reflected by the reflector 14 but also the light incident on the inner peripheral surface of the cone reflector 20 can be effectively used for illumination.

  As described above, since the light reflected by the cone reflector 20 can be effectively used for illumination, the downlight can be reduced in size compared to the conventional one without sacrificing the light shielding property. Even if it exists, the brightness which is equivalent or more can be obtained, the opening 51 formed in the ceiling board 50 can be made small, and the downlight with the good appearance when viewed from the indoor side can be provided.

  Further, in the configuration in which the dimple 16 is formed on the inner peripheral surface of the reflector 14 by diffusing the reflection of the inner peripheral surface on the opening 14a side of the reflector 14, the light is evenly distributed within the irradiation range. By being diffused, it was possible to provide the downlight 1 capable of emitting beautiful light without scallops or the like.

  Such diffusion of reflection can be obtained by frosting the opening side of the reflector 14, and this frosting can be performed together with the formation of the dimples 16 to make the light diffusion even more uniform. .

  Further, even if the dimples formed on the inner surface of the reflector 14 have a smaller diameter on the opening 14a side of the reflector 14 than the other parts, the light can be equally diffused in the same manner.

  With respect to the small-diameter dimple 16b formed on the opening 14a side, a uniform light diffusion can be obtained by forming the dimple 16b at random using a punch or the like without any gaps.

The schematic sectional drawing which shows the attachment state of the downlight of this invention. Explanatory drawing which showed the positional relationship of a reflector, a cone reflector, and a light source. It is explanatory drawing of the rotation surface shape formed in the internal peripheral surface of a cone reflector, and this rotation surface shape inclines the symmetrical axis of the parabola of (A) by angle (theta) as shown in (B), (C ), Which is obtained by rotating around the rotation axis X as shown in FIG. Explanatory drawing which shows the irradiation range of the light reflected with the reflector among the lights from a light source. Explanatory drawing which shows the irradiation range of the light which is not reflected by a reflector and a cone reflector among the lights from a light source. Explanatory drawing which shows the irradiation range of the light reflected with the cone reflector among the lights from a light source. Sectional drawing of the principal part of the conventional downlight. Sectional drawing of the principal part of the conventional downlight (thing provided with the cone).

  Next, the downlight of the present invention will be described with reference to the accompanying drawings.

  In FIG. 1, reference numeral 1 denotes a downlight according to the present invention. The downlight 1 is fitted and fixed in an opening 51 formed in a ceiling board 50 via a ring-shaped fixture 30.

  The fixture 30 includes a cylindrical portion 31 that is formed in a substantially cylindrical shape, and a flange portion 32 that protrudes from the opening edge of the cylindrical portion 31 in the outer peripheral direction. The cylindrical portion 31 of the fixture 30 is attached to the ceiling. When the flange portion 32 is inserted into the opening 51 formed in the plate from the indoor side until it hits the ceiling plate 50, the support leg 33 formed by a leaf spring or the like is locked to the periphery of the opening 51 on the back side of the ceiling plate 50. The fixture 30 is fixed in the opening 51 formed in the ceiling plate 50 by, for example, screwing the fixture 30 to the ceiling plate 50 by the support leg 33 or in addition to the support leg 33.

  A cylindrical portion 31 of the fixture 30 is formed to have an inner diameter into which the downlight 1 can be inserted. When the downlight 1 is inserted from the indoor side, a later-described cone reflector 20 provided in the downlight 1 is provided. The outer periphery is locked and the downlight 1 can be supported in the cylindrical portion 31.

  The downlight 1 of the present invention attached to the opening 51 formed in the ceiling board 50 by the fixture 30 described above is composed of a downlight body 10 and a cone reflector 20 attached to the lower end of the downlight body 10. Yes.

  The downlight body 10 houses a socket 13 to which a lamp 12 as a light source is attached and a reflector 14 that reflects light emitted from the light source 12 in a cover 11 that forms an outer shell of the downlight body 10. In the opening provided on the lower end side of the cover 10, the opening 14 a of the reflector is opened and accommodated, and the socket 13 to which the lamp 12 is attached is inserted from the upper end side of the cover 11. Thus, the lamp 12 is configured to be inserted into the reflector 14 through an insertion hole 14 b formed at the rear end of the reflector 14.

  The reflector 14 is an elliptical reflector whose inner peripheral surface is formed by the shape of a rotating surface obtained when the ellipse is rotated about the major axis of the ellipse. By processing the inner peripheral surface into a reflecting surface, The light from the lamp 12 can be reflected toward the indoor side.

  The inner peripheral surface of the reflector 14 may be formed as a mirror surface by, for example, chrome plating, or may be formed as a surface that diffuses reflection compared to the mirror surface by an aluminum base or the like. The dimple 16 may be formed on the entire inner peripheral surface.

  Preferably, the reflection on the inner surface of the reflector 14 within a predetermined depth range D (see FIG. 4) from the side of the opening 14a is more diffused than other portions. The light is evenly dissipated so that there is no bias in the illumination range of the light, so that, for example, light is shaded within the contour of the irradiated light projected on the floor surface, or the outer periphery of the contour By preventing the occurrence of unnecessary brightness that occurs on the side, the occurrence of scallops is prevented, and a beautiful light irradiation range in which the light irradiated in the contour has a substantially uniform brightness in any part of the contour is provided. So that it can be produced.

  Such diffusion of reflection may be performed by diffusing the reflection to other parts formed on the mirror surface, for example, by frosting the inner surface of the range D described above, In addition to forming dimples having the same diameter on the entire surface, frost processing may be performed on the aforementioned portion D in addition to forming dimples.

  Further, when the dimple 16 is formed on the inner peripheral surface of the reflector 14, as shown in FIG. 4, a dimple is formed on the entire inner peripheral surface of the reflector 14, and the diameter and depth of the dimple are set on the opening 14a side. The dimples 16b having a smaller diameter than the dimples 16a formed in other portions in the predetermined range D may be formed.

  Such dimples 16 (16a, 16b) can be formed, for example, by punching. For example, the dimples 16b on the small diameter side are randomly and preferably free of gaps by hand punching using a punch or the like. Can be formed.

  As an example, in the illustrated embodiment, the shape of the large-diameter dimple 16a is R8 mm and φ3 mm, and the shape of the small-diameter dimple 16b is R8 mm and φ1.5 mm.

  The range D in which the reflection surface that causes the reflection diffusion and / or the small-diameter dimple 16b is formed can be changed according to the characteristics of the individual downlights such as the size of the light source 12 and the reflector 14 to be used. However, in the illustrated embodiment, it is formed in a slightly larger range than 1/2 of the depth of the reflector 14 (the distance between the opening 14a and the lower end of the insertion hole 14b).

  A cone reflector 20 formed in a substantially cylindrical shape is attached below the downlight main body 10 configured as described above.

  The cone reflector 20 is formed in a substantially cylindrical shape having an upper end opening substantially the same diameter as or slightly smaller than the opening 14 a of the reflector 14, and a lower end opening edge 21 of the cone reflector 20 is formed. The shape and arrangement are specified so that the reference line L2 that intersects the center line C of the cone reflector 20 and reaches the opening edge 14e of the reflector 14 has a predetermined angle θ.

  The inner surface of the cone reflector 20 reflects the reflected light from the reflector 14 and reflects the reflected light below the downlight 1 except for the range of the cut-off angle θ indicated by the hatched portion in FIG. It is processed to have a relatively high reflectivity by a mirror surface or a white paint coating surface so that it can be diffused within the range between the lines L2 and L2, and the inner peripheral surface shape of the parabola It is formed by a rotating surface obtained by rotating a part.

  A part of the parabola that constitutes the rotating surface is light at any position in a part of the parabola when light from the light emitting point 12a of the light source 12 disposed at the first focal point F1 of the reflector 14 is received. Is reflected, it can be reflected to generate reflected light having an inclination angle equal to or greater than the aforementioned angle θ.

  In order to explain this rotating surface shape in an easy-to-understand manner, an example thereof will be described with reference to FIG. 3. The rotating surface shape which is the inner peripheral surface shape of the cone reflector 20 provided in the downlight 1 of the present invention is as follows. It is not limited to the shape to be described, and the light from the light source can be reflected to generate reflected light having an inclination angle greater than or equal to the inclination angle θ regardless of the position of the paraboloid. If it is, it will not be limited to the example of illustration.

  In the illustrated example, first, a predetermined parabola corresponding to the size and the like of the cone reflector 20 to be formed is created [FIG. 3 (A)].

  Next, a state is assumed in which the axis of symmetry of the parabola is inclined at an angle that should be set as the predetermined angle θ described above (FIG. 3B).

  Of the parabola whose symmetry axis is inclined as described above, when receiving light from the first focal point F1 of the reflector 14 where the light emitting point 12a of the light source 12 is received, an inclination angle equal to or greater than the inclination angle θ is obtained. Of the range in which the reflected light can be generated (in FIG. 3C, the lower range in the figure with respect to the intersection of the parabola with the straight line passing through the parabola focal point Fp and the first focal point F1 of the reflector 14). A rotation center axis X (same as the center axis C of the cone reflector 20) that intersects a part (for example, between points a and b in FIG. 3C) at an angle of 90-θ with respect to the inclined symmetry axis. The inner peripheral surface of the cone reflector 20 is formed by a rotating surface shape (FIG. 3C) obtained by rotating around the center.

  In the downlight 1 of the present invention having the downlight main body 10 and the cone reflector 20 configured as described above, the lamp 12 as the light source has a light emitting point 12a in the reflector 14 as shown in FIG. The center line of the reflector 14 and the center line C of the cone reflector 20 are arranged so as to be concentric with each other.

  Therefore, in the above configuration in which the light emitting point 12a of the lamp 12 as the light source is arranged at the first focal point of the reflector 14, the light from the light source 12 reflected by the reflector 14 is focused on the second focal point F2. Will be reflected downward.

  When the second focal point F2 of the reflector 14 is positioned below the intersection Z, the light reflected by the reflector 14 and spreading downward through the focal point F2 is not incident on the inner surface of the cone reflector 20. , And irradiated downward from the lower end opening of the cone reflector 20 (see FIG. 4).

  In FIG. 4, straight lines R1 and R1 passing through the inner peripheral edge 14e of the opening 14a of the reflector 14 and the second focal point F2 of the reflector 14 are lines representing the maximum irradiation range of the reflected light by the reflector 14, but also from FIG. As is clear, the reflected light of the reflector 14 is not incident on the inner peripheral surface of the cone reflector 20 and is irradiated within a range of an angle θ (30 ° in the present embodiment) indicated by hatching in the drawing. Irrespectively, it is irradiated to the indoor side through the lower end opening of the cone reflector 20.

  On the other hand, when the second focal point F2 is at a position where it intersects with the intersection Z between the reference line L2 and the center line C, the straight lines R1 and R1 overlap with the reference line L2, and the reflected light of the reflector 14 is similarly reflected by the cone reflector 20. Through the lower end opening of the cone reflector 20 without being incident on the inner peripheral surface of the cone reflector 20 and without being irradiated within the range of the angle θ (30 ° in the present embodiment) indicated by hatching in the figure. Irradiated indoors.

  The light irradiated in this way is within the range of the reference lines L2 and L2, and does not diffuse within the range of the angle θ set in advance, so that the light shielding characteristic of the downlight 1 is maintained at a certain value or more. be able to.

  Further, as shown in FIG. 5, a part of the light irradiated directly downward from the lamp 12 that is a light source without being reflected by the reflector 14 does not collide with the inner peripheral surface of the cone reflector 20. Directly passes through the lower end opening of the cone reflector 20 and is irradiated downward. Here, because the light emitting point 12a of the light source 12 is disposed above the intersection Z due to the arrangement of the respective parts described above, this irradiation light has a preset range of a predetermined angle θ (the hatched portion in FIG. 5). ) Will not spread.

  Further, of the light emitted from the light source 12 as shown in FIG. 6, the light incident on the inner peripheral surface of the cone reflector 20 formed as the reflecting surface is reflected and irradiated on the inner peripheral surface. However, the reflected light reflected by the inner peripheral surface of the reflector 20 on the cone formed by a parabola as shown in the cross section shown in FIG. 2 is reflected by any position on the inner peripheral surface of the cone reflector 20. However, it is reflected toward the lower end opening of the cone reflector 20 at an inclination angle larger than the inclination θ of the parabolic symmetry axis.

  As a result, it is possible to control the reflected light by the inner surface of the cone reflector 20 while preventing the reflected light from being irradiated in the range of the angle θ set in advance, and the reflected light is reflected by the inner peripheral surface of the cone reflector. Since light can also be emitted toward the indoor side and used effectively for illumination, the light from the light source can be used efficiently, and the necessary brightness can be ensured regardless of downsizing the downlight.

1 Downlight 10 Downlight body 11 Cover 12 Light source (lamp)
12a Light emitting point 13 Socket 14 Reflector 14a Opening 14b Insertion hole 14e Opening inner peripheral edge 16 Dimple 16a Dimple (large diameter)
16b Dimple (small diameter)
20 Corn reflector (corn)
21 Lower end opening edge 30 Mounting tool 31 Cylindrical portion 32 Flange portion 33 Support leg 50 Ceiling plate 51 Opening C, C 'Cone reflector center line L1 orthogonal line L2, L2' reference line R1 straight line Z center line C and reference line 2 X of the center of rotation (of the rotating surface that is the inner peripheral surface of the cone reflector)
F1 first focus (of the cone reflector)
F2 second focus (of the cone reflector)
Fp Focus of parabola θ Cut off angle 110 Downlight body 111 Cover 112 Light source (lamp)
113 socket 114 reflector 114a opening (of reflector)
132 Frame 150 Ceiling panel 151 Opening

Claims (6)

In a downlight comprising a light source, a bowl-shaped reflector that reflects light from the light source downward, and a substantially cylindrical cone disposed coaxially with the reflector below the reflector opening,
The cone is formed as a cone reflector having an inner peripheral surface as a reflection surface,
The inner peripheral surface of the reflector is formed by a spheroidal surface obtained by rotating the ellipse around the major axis of the ellipse, and the first focal point of the reflector is disposed in a space surrounded by the inner peripheral surface of the reflector. , Placing the second focal point in the cone reflector;
The reflector and the cone reflector are formed such that a reference line intersects the center line of the cone reflector and a reference line connecting a lower end opening edge of the cone reflector and an inner peripheral edge of the opening of the reflector has a predetermined angle. , The second focal point of the reflector is disposed at a position overlapping the intersection of the reference line and the center line of the cone reflector, or below the intersection,
The light emitting point of the light source is disposed at the first focal point of the reflector, and the inner peripheral surface of the cone reflector reflects incident light from the light emitting point of the light source and has an inclination angle larger than the predetermined angle. A downlight characterized by having a rotating surface obtained by rotating a part of a parabola that generates reflected light.   2. The downlight according to claim 1, wherein reflection of the inner peripheral surface on the opening side of the reflector is diffused as compared with other portions.   The downlight according to claim 2, wherein an inner peripheral surface on the opening side of the reflector is frosted.   3. The downlight according to claim 1, wherein dimples are formed on an inner peripheral surface of the reflector.   The downlight according to claim 4, wherein a diameter of a dimple formed in a predetermined range on the opening side of the reflector is smaller than a diameter of a dimple formed in another portion.   6. The downlight according to claim 5, wherein the dimples formed within a predetermined range on the opening side of the reflector are randomly formed without a gap.

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