JP2016091855A - Luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminaire using a LED as a light source for developing high floor surface illuminance when installed on a ceiling surface.SOLUTION: A luminaire 1 includes a LED 21, and a cover 3 covering the LED 21, the cover 3 having prism parts 52, 53 each including prisms 51 for refracting light from the LED 21 in the direction of an optical axis Ax, and a no-prism part 54 not including the prism 51, the prism parts 52, 53 being provided at both ends in a lateral direction S of the cover 3, respectively, the no-prism part 54 being provided continuously with the prism parts 52, 53 in a region held between the prism parts 52, 53. In this configuration, the light emitted from the LED 21 in the direction of the optical axis Ax is transmitted through the no-prism part 54 while less decaying, and the light emitted from the LED 21 to the lateral side of the luminaire is refracted in the direction of the optical axis Ax by the prisms 51. Thus, more light is delivered in the direction of the optical axis Ax to develop high floor surface illuminance in the case of installation on the ceiling surface.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lighting fixture using an LED as a light source.

  LEDs are attracting attention as light sources that can replace incandescent lamps and fluorescent lamps because they can emit light with high power and high luminance and have a long lifetime. As a lighting fixture using such an LED as a light source, one having a plurality of LEDs arranged in a row and a bowl-shaped cover that collectively covers these LEDs is known (for example, Patent Documents). 1).

  The lighting fixture as described above replaces, for example, a base light using a straight tube fluorescent lamp as a light source, but the light emitting area of the LED is smaller than the light emitting area of the straight tube fluorescent lamp. Therefore, when a lighting fixture using an LED as a light source is viewed from the light irradiation surface side, the “graininess” of the LED is conspicuous, and the appearance of the light source is different from the lighting fixture using a straight tube fluorescent lamp as a light source. Therefore, in order to reduce the graininess of the LED, it is conceivable to include a diffusing material for diffusing light in the cover, to diffuse the light from the LED and to emit it to the outside.

JP 2013-206849 A

  However, when the lighting fixture as described above is installed on the ceiling surface, the light from the LED is diffused in various directions, so that the amount of light emitted from the lighting fixture in the wall surface direction (side of the fixture) increases. Thus, less light is irradiated in the floor direction (front direction of the appliance). Therefore, high floor surface illumination cannot be given.

  This invention solves the said subject, and it aims at providing the lighting fixture which can give a high floor surface illumination intensity, when it installs in a ceiling surface.

  The present invention is a lighting fixture including a plurality of LEDs arranged in a row and a cover that collectively covers the plurality of LEDs, and the cover is long in a direction in which the plurality of LEDs are arranged. And a prism portion including a prism that refracts light from the LED in the optical axis direction of the LED, and a non-prism portion that does not include the prism. The cover is provided at both ends in the short direction of the cover over the longitudinal direction of the cover, and the non-prism portion is sandwiched by the prism portion continuously with the prism portion over the longitudinal direction of the cover. It is provided in the area.

  According to the lighting apparatus of the present invention, the light emitted from the LED in the optical axis direction (appliance front direction) is transmitted to the outside through the non-prism portion with little attenuation, and the light emitted from the LED to the side of the apparatus is The light is refracted in the optical axis direction by the prism and irradiated to the outside. For this reason, the amount of light irradiated in the front direction of the appliance increases, so that high floor surface illuminance can be provided when installed on the ceiling surface.

The perspective view of the lighting fixture which concerns on one Embodiment of this invention. II sectional view taken on the line of FIG. The figure which shows the optical path of the light radiate | emitted from LED which comprises the said lighting fixture. The figure which shows the floor surface illumination distribution by the light irradiated from the said lighting fixture installed in the ceiling surface. Sectional drawing of the lighting fixture which concerns on a 1st prior art example. The figure which shows the floor surface illumination distribution by the light irradiated from the lighting fixture which concerns on the said 1st prior art example installed in the ceiling surface. Sectional drawing of the lighting fixture which concerns on a 2nd prior art example. The figure which shows the floor surface illumination distribution by the light irradiated from the lighting fixture which concerns on the said 2nd prior art example installed in the ceiling surface. (A) (b) is sectional drawing of the lighting fixture which concerns on the 1st modification of the said embodiment. (A) and (b) are sectional drawings of the lighting fixture which concerns on the 2nd modification of the said embodiment. (A) and (b) are sectional drawings of the lighting fixture which concerns on the 3rd modification of the said embodiment. Sectional drawing of the lighting fixture which concerns on the reference example of this invention. The figure which shows the optical path of the light radiate | emitted from LED which comprises the lighting fixture which concerns on the said reference example. The figure which shows the floor surface illumination distribution by the light irradiated from the lighting fixture which concerns on the said reference example installed in the ceiling surface. Sectional drawing of the lighting fixture which concerns on a 3rd prior art example. The figure which shows the floor surface illumination distribution by the light irradiated from the lighting fixture which concerns on the said 3rd prior art example installed in the ceiling surface. The figure which shows the floor surface illumination distribution by the light irradiated from the lighting fixture which concerns on the said 2nd prior art example installed in the ceiling surface. (A) (b) is sectional drawing of the lighting fixture which concerns on the 1st modification of the said reference example. (A) (b) is sectional drawing of the lighting fixture which concerns on the 2nd modification of the said reference example.

  A lighting apparatus according to an embodiment of the present invention will be described with reference to FIGS. As illustrated in FIG. 1, the luminaire 1 includes a light source unit 2, a cover 3 that transmits light from the light source unit 2, and a housing 4 that holds the light source unit 2 and the cover 3.

  The light source unit 2 includes a plurality of LEDs 21, a wiring board 22 on which the LEDs 21 are mounted, and a circuit unit 23 that controls power supply to the LEDs 21. The plurality of LEDs 21 are arranged in a row at predetermined intervals in a state where the optical axes Ax are aligned in a predetermined direction (upward in the illustrated example). The LED 21 includes, for example, an LED chip that emits blue light, a sealing material that seals the LED chip, and a phosphor that is dispersed in the sealing material and converts blue light into yellow light. It is comprised by white LED which radiate | emits white light by mixing blue light and yellow light mutually.

  The wiring board 22 is formed in a rectangular shape that is elongated along the direction L in which the LEDs 21 are arranged, and the LEDs 21 are mounted on one surface (the upper surface in the illustrated example). The wiring board 22 has a wiring pattern (not shown) connected to each LED 21, and these wiring patterns are connected to the circuit unit 23. The circuit unit 23 is disposed on the surface of the wiring board 22 opposite to the surface on which the LED 21 is mounted, and has various circuit elements (not shown) that control power supply from the commercial power source to the LED 21.

  The cover 3 is formed in a bowl shape that is elongated along the direction L, and covers the plurality of LEDs 21 in a state where the top 31 of the curved surface intersects the optical axis Ax. The cover 3 is made of a transparent material that transmits light from the LED 21 without diffusing, for example, a transparent acrylic resin or a transparent polycarbonate resin.

  In the illustrated example, the housing 4 includes a pair of rails 41 provided in the (longitudinal) direction L at each of both ends in the short direction S of the cover 3. The rail 41 has an attachment structure (not shown) for attaching the luminaire 1 to a construction surface such as a ceiling surface or a wall surface.

  As shown in FIG. 2, in the cross section in the short direction S of the cover 3, the cover 3 does not include the prism parts 52 and 53 including the prism 51 that refracts the light from the LED 21 in the optical axis Ax direction. And a non-prism portion 54. The prism portions 52 and 53 are provided at both ends in the short direction S of the cover 3 over the longitudinal direction L of the cover 3 (the direction extending from the front side to the back side of the paper). The prism 51 refracts the light from the LED 21 in the direction of the optical axis Ax.

  The non-prism portion 54 is provided in a region sandwiched between the prism portions 52 and 53 continuously to the prism portions 52 and 53 in the longitudinal direction L. The non-prism portion 54 is provided so as to intersect the optical axis Ax, and the average thickness is thinner than the prism portions 52 and 53 by the amount not including the prism 51.

  An angle formed between a line L1 connecting one end 54a of the non-prism part 54 and the LED 21 and a line L2 connecting the other end 54b of the non-prism part 54 and the LED 21 is defined as θ1. Further, an angle formed between the line L1 and the line L3 connecting the one end 3a of the cover 3 and the LED 21 is θ2, and an angle formed between the line L2 and the line L4 connecting the other end 3b of the cover 3 and the LED 21. Is θ3 <θ2 = θ3. What is necessary is just to adjust the magnitude | size of (theta) 1 with the magnitude | size of the room in which the lighting fixture 1 is installed. For example, when the lighting fixture 1 is installed on the ceiling surface with the distance from the wall surface to the LED 21 being 2.66 meters, if the height from the floor surface to the ceiling surface is 8 meters, θ1 = about 40 degrees and θ2 If it is set to = θ3 = about 70 degrees, the floor surface can be illuminated with high illuminance and uniformly.

  As shown in FIG. 3, light (indicated by a one-dot chain line arrow) emitted from the LED 21 in the optical axis Ax direction (front direction of the instrument) passes through the non-prism portion 54 and is irradiated to the outside. At this time, the light from the LED 21 is difficult to attenuate because the non-prism portion 54 has a thinner average thickness than the prism portions 52 and 53. On the other hand, light emitted from the LED 21 to the side of the instrument (indicated by a two-dot chain line arrow) is refracted in the optical axis Ax direction by the prism 51 and irradiated to the outside. Thereby, according to the lighting fixture 1, the light irradiated to the fixture front direction can be increased.

  Therefore, as shown in FIG. 4, the floor illuminance obtained when the lighting fixtures 1 are arranged in a 4 × 6 matrix on a ceiling surface of 20 meters long × 32 meters wide is> 300 in a wide region (shown by dots). Lux. At this time, as shown in Table 1, the average illuminance on the floor is 277 lux, and the illuminance unevenness G1 expressed by the ratio of the minimum illuminance to the average illuminance is 0.351, which is expressed by the ratio of the minimum illuminance to the maximum illuminance. Illuminance unevenness G2 to be performed was 0.276, and the light extraction efficiency was 99%. Here, the light extraction efficiency is calculated assuming that the light extraction efficiency of a conventional lighting fixture 10a described later is 100%.

  On the other hand, as shown in FIG. 5, there is conventionally known a lighting fixture 10 a in which a prism is not provided in the cover 30 and the cover 30 includes a diffusion material 40 that diffuses light. In such a lighting fixture 10a, much light (indicated by a one-dot chain line arrow) is emitted to the side of the appliance, and less light (indicated by a two-dot chain line arrow) is emitted in the front direction of the appliance. Therefore, as shown in FIG. 6, when the lighting fixture 10a is installed on the ceiling surface, a region (indicated by dots) in which the floor illuminance is 300 lux or more is reduced. As shown in Table 2, the average illuminance of the floor obtained at this time was 246 lux, the illuminance unevenness G1 and G2 were 0.407 and 0.317, respectively, and the light extraction efficiency was 100%. Thus, in the conventional lighting fixture 10a, the floor surface illumination intensity as much as the lighting fixture 1 of this invention cannot be given.

  Moreover, as shown in FIG. 7, the lighting fixture 10b in which the prism 50 is provided in the whole cover 30 is also known. In such a lighting fixture 10 b, the cover 30 is thickened by the amount of the prism 50, so that the irradiation light is easily attenuated when passing through the cover 30. Therefore, as shown in FIG. 8, when the luminaire 10b is installed on the ceiling surface, the area where the floor illuminance is 300 lux or more (indicated by dots) is larger than that of the luminaire 10a described above. , Not as large as in the case of the luminaire 1. As shown in Table 3, the average illuminance of the floor obtained at this time was 268 lux, and the conventional luminaire 10b could not provide the illuminance of the floor as much as the luminaire 1 of the present invention. The illuminance unevenness G1 and G2 were 0.342 and 0.249, respectively, and the uniformity of the light emitted from the lighting fixture 10b was lower than the uniformity of the light emitted from the lighting fixture 1. The light extraction efficiency of the lighting fixture 10b was 97%.

  Next, the lighting fixture which concerns on the 1st modification of the said embodiment is demonstrated with reference to Fig.9 (a) (b). As shown in FIG. 9A, in the lighting fixture 1a, θ1 = θ2 = θ3 (= 60 degrees). By setting θ1, θ2, and θ3 in this way, the lighting fixture 1a is placed on the ceiling surface so that the distance from the wall surface to the LED 21 is 2.66 meters in a room having a height of 5 meters from the floor surface to the ceiling surface. If it installs in, it can illuminate a floor surface with high illumination intensity uniformly. In addition, as shown in FIG. 9B, in the lighting fixture 1b, θ1> θ2 = θ3. By setting θ1, θ2, and θ3 in this way, the lighting fixture 1b is adjusted so that the distance from the wall surface to the LED 21 is 2.66 meters in a room where the height from the floor surface to the ceiling surface is lower than 5 meters. If installed on the ceiling surface, the floor surface can be illuminated uniformly with high illuminance.

  Next, the lighting fixture which concerns on the 2nd modification of the said embodiment is demonstrated with reference to Fig.10 (a) (b). In the lighting fixture of the present modification, the non-prism portion 54 is displaced from the center of the cover 3 because θ3 is configured to be larger than θ2. As shown to Fig.10 (a), in the lighting fixture 1c, the non-prism part 54 is biased to the one side of the optical axis Ax in the state which cross | intersected the optical axis Ax. Moreover, as shown in FIG.10 (b), in the lighting fixture 1d, the non-prism part 54 does not cross | intersect the optical axis Ax. According to such luminaires 1c and 1d, light with high illuminance (indicated by a one-dot chain line arrow) that has passed through the non-prism portion 54 and exited to the outside is strong in a direction at an angle with respect to the optical axis Ax. Irradiated. In this way, by adjusting the position of the non-prism portion 54, the light distribution of the irradiation light can be arbitrarily adjusted.

  Next, the lighting fixture which concerns on the 3rd modification of the said embodiment is demonstrated with reference to Fig.11 (a) (b). In the lighting fixture of this modification, the non-prism portion 54 further includes a diffusion portion 6 that diffuses light. As shown in FIG. 11A, in the luminaire 1e, the diffusing portion 6 is formed by applying a texture to the inner surface (light incident surface) of the non-prism portion 54 or applying a paint containing a diffusing material that diffuses light. Has been. On the other hand, as illustrated in FIG. 11B, in the lighting fixture 1 f, the diffusing portion 6 is formed by including a diffusing material 61 in the non-prism portion 54. By providing the diffusing unit 6 in this manner, high-luminance light emitted from the LED 21 in the optical axis Ax direction is diffused in various directions by the diffusing unit 6, so that glare is generated by light emitted from the non-prism unit 54. Can be prevented. Moreover, since it becomes difficult to feel the grain feeling of LED21 when a user looks at the cover 3 of the lighting fixtures 1e and 1f, the appearance of the lighting fixtures 1e and 1f can be improved.

  Next, a lighting apparatus according to a reference example of the present invention will be described with reference to FIGS. As shown in FIG. 12, in the lighting fixture 1 g, the prism 51 is provided on the entire surface of the cover 3, and the diffusion unit 6 is provided on a part of the cover 3. In the example shown in the figure, the diffusing unit 6 is formed by applying a texture to the inner surface of the cover 3 or applying a paint containing a diffusing material that diffuses light, as in the case of the lighting fixture 1e (see FIG. 11A). Formed and intersecting with the optical axis Ax.

  The angle formed between the line L5 connecting one end 6a of the diffusing unit 6 and the LED 21 with the line L6 connecting the other end 6b of the diffusing unit 6 and the LED 21 is θ4, and the angle formed between the line L5 and the line L3. θ4 <θ5 = θ6, where θ5 is the angle between the line L6 and the line L4 and θ6. What is necessary is just to adjust the magnitude | size of (theta) 4 with the magnitude | size of the room in which the lighting fixture 1g is installed. For example, when the lighting fixture 1g is installed on the ceiling surface with the distance from the wall surface to the LED 21 being 2.66 meters, if the height from the floor surface to the ceiling surface is 8 meters, θ4 = about 40 degrees and θ5 If it is set to = θ6 = about 70 degrees, the floor surface can be illuminated with high illuminance and uniformly.

  As shown in FIG. 13, high-intensity light (indicated by a one-dot chain line) emitted from the LED 21 in the direction of the optical axis Ax is diffused by the diffusion unit 6 and irradiated to the outside. Thereby, the occurrence of glare can be prevented. On the other hand, the light (indicated by a two-dot chain line arrow) emitted from the LED 21 to the side is refracted by the prism 51 of the cover 3 and irradiated in the optical axis Ax direction without being diffused. Thus, according to the lighting fixture 1g, the light emitted from the LED 21 in the lateral direction can be efficiently irradiated in the optical axis Ax direction while preventing glare due to the high-intensity light emitted from the LED 21 in the optical axis Ax direction. it can.

  Therefore, as shown in FIG. 14, when such a lighting fixture 1g is arranged in a 4 × 6 matrix on the ceiling surface, it is possible to give high floor surface illuminance as a whole while preventing glare. As shown in Table 4, the average illuminance of the floor surface at this time was 313 lux, and the illuminance unevenness G1 and G2 were 0.334 and 0.245, respectively.

  On the other hand, as shown in FIG. 15, a lighting fixture 10 c is known that has a prism 50 formed on the entire surface of the cover 30 and does not have a structure like the diffusion portion 6 of the lighting fixture 1 g. As shown in FIG. 16, when such a lighting fixture 10c is installed on a ceiling surface, the generation of glare cannot be sufficiently prevented, and the floor surface is 400 lux or more than the lighting fixture 1g of the present invention. The area that gives illuminance has increased. As shown in Table 5, the average illuminance on the floor obtained at this time was 327 lux, and the illuminance unevenness G1 and G2 were 0.301 and 0.205, respectively. Thus, the uniformity degree of the light irradiated from the conventional lighting fixture 10c was lower than the uniformity degree of the light irradiated from the lighting fixture 1g.

  Moreover, as shown in FIG. 17, when the lighting fixture 10b (refer FIG. 7) mentioned above is installed in a ceiling surface, since the cover 30 contains the diffusing material 40, the light from LED20 is diffused. As a result, the illumination on the floor surface is lowered. As shown in Table 6, the average illuminance of the floor obtained at this time was 300 lux, and the illuminance unevenness G1 and G2 were 0.364 and 0.281, respectively. Thus, the conventional luminaire 10b could not give the floor surface illuminance as high as the luminaire 1g. The values in Table 6 and Table 3 are different from each other because of the difference in test conditions.

  Next, the lighting fixture which concerns on the 1st modification of the said reference example is demonstrated with reference to Fig.18 (a) (b). As shown in FIG. 18A, in the lighting fixture 1h, θ4 = θ5 = θ6 (= 60 degrees). By setting θ4, θ5, and θ6 in this way, the lighting fixture 1h is placed on the ceiling surface so that the distance from the wall surface to the LED 21 is 2.66 meters in a room having a height of 5 meters from the floor surface to the ceiling surface. If it installs in, it can illuminate a floor surface with high illumination intensity uniformly. Further, as shown in FIG. 18B, in the lighting fixture 1i, θ4> θ5 = θ6. By setting θ4, θ5, and θ6 in this way, the lighting fixture 1b is adjusted so that the distance from the wall surface to the LED 21 is 2.66 meters in a room where the height from the floor surface to the ceiling surface is lower than 5 meters. If installed on the ceiling surface, the floor surface can be illuminated uniformly with high illuminance.

  Next, the lighting fixture which concerns on the 2nd modification of the said reference example is demonstrated with reference to Fig.19 (a) (b). In the lighting fixture of the present modification, θ6 is configured to be larger than θ5, so that the diffusing portion 6 is arranged so as to be shifted from the center of the cover 3. As shown to Fig.19 (a), in the lighting fixture 1j, the spreading | diffusion part 6 is biased to the one side of the optical axis Ax in the state which cross | intersected the optical axis Ax. Moreover, as shown in FIG.19 (b), in the lighting fixture 1k, the spreading | diffusion part 6 does not cross | intersect the optical axis Ax. By doing in this way, the light distribution of irradiation light can be changed arbitrarily.

  In addition, the lighting fixture which concerns on this invention is not limited to the said embodiment and its modification, A various deformation | transformation is possible. For example, the prism may be provided on the inner surface (light incident surface) of the cover. Further, the diffusing section may be provided on the outer surface (light emitting surface) of the cover, or may include a diffusing material that diffuses light.

1, 1a to 1k Lighting fixture 21 LED
3 Cover 51 Prism 52, 53 Prism part 54 Non-prism part 54a One end part 54b of the non-prism part Other end part 6 of the non-prism part Diffusion part 61 Diffuser Ax (LED) Optical axis L Longitudinal direction S Short direction

Claims (8)

A lighting apparatus comprising a plurality of LEDs arranged in a row and a cover that collectively covers the plurality of LEDs,
The cover is formed in a bowl shape elongated in the direction in which the plurality of LEDs are arranged, and does not include the prism portion including a prism that refracts light from the LED in the optical axis direction of the LED. A non-prism portion,
The prism portions are respectively provided at both ends in the short direction of the cover over the longitudinal direction of the cover,
The said non-prism part is provided in the area | region pinched | interposed by this prism part continuously with the said prism part over the longitudinal direction of the said cover.   The lighting apparatus according to claim 1, wherein the non-prism portion is provided so as to intersect with an optical axis of the LED. In the cross section in the short direction of the cover,
An angle formed between a line L1 connecting one end portion of the non-prism portion and the LED and a line L2 connecting the other end portion of the non-prism portion and the LED is θ1,
The angle between the line L1 and the line L3 connecting one end of the cover and the LED is θ2,
When the angle formed by the line L2 and the line L4 connecting the other end of the cover and the LED is θ3,
The lighting apparatus according to claim 2, wherein θ1 <θ2 = θ3. In the cross section in the short direction of the cover,
An angle formed between a line L1 connecting one end portion of the non-prism portion and the LED and a line L2 connecting the other end portion of the non-prism portion and the LED is θ1,
The angle between the line L1 and the line L3 connecting one end of the cover and the LED is θ2,
When the angle formed by the line L2 and the line L4 connecting the other end of the cover and the LED is θ3,
The lighting apparatus according to claim 2, wherein θ1> θ2 = θ3. In the cross section in the short direction of the cover,
An angle formed between a line L1 connecting one end portion of the non-prism portion and the LED and a line L2 connecting the other end portion of the non-prism portion and the LED is θ1,
The angle between the line L1 and the line L3 connecting one end of the cover and the LED is θ2,
When the angle formed by the line L2 and the line L4 connecting the other end of the cover and the LED is θ3,
The lighting apparatus according to claim 2, wherein θ1 = θ2 = θ3. The non-prism part has a diffusion part for diffusing light,
The lighting apparatus according to claim 1, wherein the prism portion is made of a transparent material and does not diffuse light.   The lighting device according to claim 6, wherein the diffusion part is formed by applying a texture to the non-prism part or applying a paint containing a diffusion material that diffuses light.   The lighting device according to claim 6, wherein the diffusing portion is formed by including a diffusing material that diffuses light in the non-prism portion.