JP6127347B2 - lighting equipment - Google Patents

Description

  The present invention relates to a lighting fixture using a light guide plate.

  2. Description of the Related Art Conventionally, a so-called edge light type lighting apparatus is known that includes a light guide plate made of a plate-like light-transmitting member and a light source that inputs light to an end face in the thickness direction of the light guide plate. In this conventional lighting fixture, light input into the light guide plate is reflected or refracted within the light guide plate, and then emitted from the front and back surfaces of the light guide plate to the outside of the light guide plate. Then, a lighting device has been proposed in which a prism is formed on the back surface of the light guide plate with a dot pattern or minute unevenness, and the light emitted from the light guide plate is controlled by the prism provided on the back surface of the light guide plate (for example, , See Patent Document 1).

JP 2013-109951 A

  As described above, the luminaire using the light guide plate is arranged with the surface side (the surface on which the prism is not provided) of the light guide plate facing the irradiation area (illumination target). Therefore, it is desirable that the light distribution of the luminaire has a large amount of light emitted from the surface of the light guide plate and a small amount of light emitted from the back surface of the light guide plate.

  In a lighting fixture in which a prism is disposed on the back surface of the light guide plate to control light distribution, the ratio of light emitted from the surface of the light guide plate not provided with the prism is increased to provide a light distribution suitable for the lighting fixture. It is required to get.

  This invention is made | formed in view of the said reason, The objective is the lighting fixture which can raise the ratio of the light radiate | emitted from the other surface of a light-guide plate, when a prism is provided in one surface of a light-guide plate. Is to provide.

  The lighting fixture of the present invention is formed of a plate-like light-transmissive member, and has a first surface and a second surface facing each other as an output surface for emitting light, and the first surface of the light guide plate And a light source that makes light incident on the end surface along the thickness direction of the light guide plate, and the intensity of light output from the light source. The ½ directivity angle, which is the angle between the locations at which the half of the peak value is, is 60 ° or less in the thickness direction of the light guide plate, and the height H of the protrusion and the protrusion are the same as those of the light guide plate. A ratio H / R with a radius R of a portion in contact with the first surface satisfies 0.25 or more and 0.50 or less.

  In this invention, the light source is provided between a light emitting element that emits light and the light emitting element and the end face of the light guide plate, and the 1/2 directivity angle is 60 ° or less in the thickness direction of the light guide plate. And a condensing lens that controls light distribution of the light emitted from the light emitting element.

  In this invention, it is preferable that the said condensing lens is provided in the said end surface of the said light-guide plate.

  In this invention, it is preferable that the said condensing lens has a recessed part which accommodates the said light source, and a reflective surface from the periphery of the said recessed part to the outer edge of the said end surface of the said light-guide plate.

  In this invention, the ratio H / R between the height H of the protrusion and the radius R of the portion where the protrusion contacts the first surface of the light guide plate satisfies 0.26 or more and 0.44 or less. Is preferred.

  In this invention, the light guide plate has a second end surface facing the first end surface, and the irradiation surface irradiated with light emitted from the second surface is more effective than the first end surface. It is preferable that the second end surface is inclined so that the second end surface approaches, and an angle θ1 at which the light guide plate is inclined with respect to a reference plane parallel to the irradiation surface satisfies 5 ° or more and 25 ° or less.

  In this invention, the ratio H / R between the height H of the protrusion and the radius R of the portion where the protrusion contacts the first surface of the light guide plate satisfies 0.30 or more and 0.43 or less, The angle θ1 at which the light guide plate is inclined with respect to the reference plane preferably satisfies −250 · (H / R) + 100 ≦ θ1 ≦ −335.7 · (H / R) +149.2.

  In this invention, it is preferable to provide a reflecting member that reflects light emitted from the first surface of the light guide plate so as to face the first surface.

  As described above, in the present invention, the 1/2 directivity angle, which is the angle between the locations where the intensity of the light output from the light source becomes half of the peak value, is 60 ° or less in the thickness direction of the light guide plate, The ratio H / R between the height H of the protruding portion of the convex curved surface made of translucent resin disposed on one surface of the light guide plate and the radius R of the portion where the protruding portion contacts the first surface of the light guide plate is 0. Since 25 or more and 0.50 or less are satisfied, when a protrusion (prism) is provided on one surface of the light guide plate, there is an effect that the ratio of light emitted from the other surface of the light guide plate can be increased.

It is sectional drawing which shows the structure of the lighting fixture of Embodiment 1. FIG. It is a disassembled perspective view which shows the structure of a lighting fixture same as the above. It is a perspective view which shows the structure of a lighting fixture same as the above. It is sectional drawing which shows the structure of a light source same as the above. (A) (b) It is a block diagram which shows a prism same as the above. It is explanatory drawing which shows the path | route of the light which injected into the light-guide plate same as the above. It is a perspective view which shows the model of a simulation same as the above. (A) (b) It is explanatory drawing which shows the 1/2 directivity angle of a light source same as the above. It is a perspective view which shows the range classification | category of the light radiate | emitted from a light guide plate same as the above. (A) (b) It is explanatory drawing which shows light distribution preferable for a lighting fixture same as the above. (A) (b) It is explanatory drawing which shows light distribution unsuitable for the lighting fixture same as the above. It is a graph which shows the relationship between the flatness same as the above and an output ratio. It is a graph which shows the relationship between a 1/2 directivity angle same as the above, and an output ratio. It is a graph which shows the relationship between the flat rate same as the above, and the ratio of front light. It is explanatory drawing which shows the quality of the light distribution based on the simulation result same as the above. It is explanatory drawing which shows the quality of the light distribution based on the simulation result same as the above. It is explanatory drawing which shows the quality of the light distribution based on the simulation result same as the above. It is explanatory drawing which shows the quality of the light distribution based on the simulation result same as the above. (A) (b) It is explanatory drawing which shows actual light distribution by only the light source same as the above. (A) (b) It is explanatory drawing which shows the actual light distribution by the lighting fixture same as the above. It is a perspective view which shows the structure which integrally formed the light guide plate and condensing lens same as the above. It is a perspective view which shows the structure of the lighting fixture of Embodiment 2. FIG. It is a side view which shows the structure of a lighting fixture same as the above. It is explanatory drawing which shows light distribution distribution same as the above. (A)-(f) It is explanatory drawing which shows the light distribution for every flatness H / R of the lighting fixture of Embodiment 3. FIG. It is explanatory drawing which shows a narrow angle light distribution at the time of mixing and using the prism of two flatness ratio H / R same as the above. It is explanatory drawing which shows wide angle light distribution at the time of mixing and using the prism of three flatness ratio H / R same as the above. (A) (b) It is a top view which shows the other structure of the condensing lens same as the above. It is a perspective view which shows the structure of the lighting fixture of Embodiment 4. It is a side view which shows the structure of a lighting fixture same as the above. (A) (b) It is explanatory drawing which shows the light distribution of the lighting fixture of inclination angle (theta) 1 = 0 degree same as the above. (A) (b) It is explanatory drawing which shows the light distribution of the lighting fixture which inclined the electrically conductive board same as the above. It is explanatory drawing which shows the derivation method of a lower limit inclination angle same as the above and an upper limit inclination angle. It is a table figure which shows the lower limit inclination angle and upper limit inclination angle which were derived | led-out same as the above. It is a graph which shows the range of inclination-angle (theta) 1 same as the above. It is the schematic which shows another structure of the lighting fixture same as the above. It is a graph which shows the range of inclination-angle (theta) 1 same as the above. It is a side view which shows the structure of another lighting fixture same as the above.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The lighting fixture of this embodiment is comprised from the light source 1, the fixing jig 2, and the light-guide plate 3, as shown in FIGS.

  The light source 1 includes an LED unit 11 and a condenser lens 12.

  The LED unit 11 is configured by mounting a plurality of LED elements 11b on the surface of a long substrate 11a. The LED elements 11b are arranged in a line at equal intervals along the longitudinal direction of the substrate 11a.

  The substrate 11a is held by the fixing jig 2. The fixing jig 2 is formed in a long shape formed in a shape (cross-sectional U shape) that surrounds three sides with a metal material, and the center piece 21 and each side edge in the width direction of the center piece 21 in the same direction, respectively. It is composed of standing side pieces 22 and 23. The substrate 11 a is disposed on the central piece 21 between the side pieces 22 and 23. The central piece 21 has a radiation fin 24 formed on the surface opposite to the side on which the side pieces 22 and 23 are provided, and has a function of radiating heat generated by the LED element 11b. The LED unit 11 is supplied with lighting power from a lighting circuit (not shown) via the power line 4, and the LED element 11 b emits light.

  The condensing lens 12 is formed in the rod body which opposes the LED unit 11 with transparent resin, glass, etc. FIG. As shown in FIG. 4, the cross-sectional shape of the condenser lens 12 in the width direction is formed in a substantially bowl shape whose diameter is increased from one end to the other end. On one end side of the condenser lens 12, a substantially rectangular recess 12a is formed in the longitudinal direction, and a bottom surface 12b of the recess 12a is formed in a convex lens shape. The recess 12a forms a space in which the LED element 11b is accommodated when the condenser lens 12 is disposed on the substrate 11a. That is, the light emitted from the LED element 11 b enters the condenser lens 12 from the bottom surface 12 b and the side surface 12 c of the recess 12 a, and the bottom surface 12 b and the side surface 12 c form the light incident surface of the condenser lens 12. The other end side of the condenser lens 12 forms a planar light exit surface 12d, and light incident from the light entrance surface is reflected and refracted in the condenser lens 12 and then exits from the light exit surface 12d. The side surface in the longitudinal direction of the condensing lens 12 is formed with a curved reflecting surface 12e bulging outward, and the reflecting surface 12e is continuous from the periphery of the recess 12a to the outer edge of the light exit surface 12d. The reflection surface 12e totally reflects the light incident from the side surface 12c of the recess 12a. The condensing lens 12 is called a TIR (Total Internal Reflection) lens and has a function of controlling the light distribution of the light emitted from the LED unit 11, and generally has excellent light efficiency.

  The light guide plate 3 is formed in a rectangular plate shape using a translucent member such as glass or acrylic. On one end surface 31 (first end surface) of the light guide plate 3, the light exit surface 12d of the condensing lens 12 is disposed so as to oppose, and the reflecting surface 12e of the condensing lens 12 is guided from the periphery of the recess 12a. It reaches the outer edge of the end face 31 of the optical plate 3. The end surface 31 of the light guide plate 3 and the light exit surface 12d of the condenser lens 12 are in contact with each other in a state of facing each other, and the light from the LED element 11b whose light distribution is controlled by the condenser lens 12 ( Light emitted from the light source 1 enters. The light incident on the end surface 31 is guided through the light guide plate 3 and leaks and exits from the exit surface 32 (second surface) and the exit surface 33 (first surface) substantially orthogonal to the end surface 31. The light guide plate 3 has an end surface 35 (second end surface) facing the end surface 31 to which the light source 1 is attached.

  The exit surface 33 of the light guide plate 3 has a plurality of prisms 34 formed on the outer surface in order to reflect the light incident from the end surface 31 toward the exit surface 32 side. The prism 34 is formed on the exit surface 33 by curing the light-transmitting resin droplets discharged onto the exit surface 33 by the ink jet device, and has a convex curved protrusion shape (FIG. 5A). (See (b)). Part of the light that enters from the end face 31 and travels toward the exit surface 33 is reflected by the prism 34 and exits from the exit surface 32. That is, the prism 34 is formed to reflect the light incident on the light guide plate 3 toward the exit surface 32.

  By using the ink jet apparatus, a mold is not required for manufacturing the light guide plate 3, and an initial investment for manufacturing a mold for each light guide plate having a different size, type, or the like is not required, and cost can be reduced. Further, since the print pattern of the prism 34 can be freely set by changing the program for operating the ink jet apparatus, a print pattern with high design can be produced relatively easily.

  Since the luminaire of this embodiment is installed with the emission surface 32 facing the direction in which the region to be illuminated exists, the light is condensed so that the emitted light from the emission surface 32 is larger than the emission surface 33. Light distribution control by the lens 12 and light reflection control by the prism 34 of the light guide plate 3 are performed.

  First, as shown by solid lines Y1 and Y2 in FIG. 6, when the incident angle of light incident on the light guide plate 3 from the end face 31 is shallow, the light traveling toward the prism 34 is likely to reach the vicinity of the periphery of the prism 34. Most of the light reflected in the vicinity of the periphery of 34 is emitted from the emission surface 32 side. Further, as shown by the broken line Y3 in FIG. 6, when the incident angle of light incident on the light guide plate 3 from the end face 31 is deep, most of the light traveling toward the prism 34 is refracted and transmitted by the surface shape of the prism 34. The light exits from the exit surface 33 side.

  Therefore, in the present embodiment, the light distribution from the light source 1 is optimized, and the shape of the prism 34 is also optimized, so that the light emitted from the light emission surface 32 is dominant.

  First, the optimal light distribution of the light source 1 and the optimal shape of the prism 34 were obtained by simulation. FIG. 7 is a model of a lighting fixture used for the simulation.

  Ten LED elements 11b are arranged on the substrate 11a at intervals of 10 mm, and the light guide plate 3 made of acrylic has a length X11 = 100 mm, a width X12 = 200 mm, and a thickness X13 = 4 mm. In addition, the light guide plate 3 has three end faces (including the end face 35) other than the end face 31 on which light emitted from the light source 1 is incident have a diffuse reflectance of 90%. Further, the coverage of the prism 34 on the exit surface 33 is 50%, and the radius R of the prism 34 is 30 μm.

  As variables for modeling, “1/2 directivity angle θa of light source 1 in the thickness direction of light guide plate 3” and “flattening ratio H / R of prism 34” are used.

  The ½ directional angle of the light source 1 in the thickness direction of the light guide plate 3 is an angle between locations where the intensity of light output from the light source 1 is half the peak value in the thickness direction of the light guide plate 3. . As shown in FIG. 8A, the condensing lens 12 narrows and outputs the directivity angle of the light emitted from the LED element 11b of the LED unit 11. The light emitted from the condenser lens 12 has a peak value at the light intensity at the approximate center Z1 of the directivity angle of the condenser lens 12. The angle θa between the portions Z2 and Z3 at which the light intensity is half of the light intensity at the center Z1 is the 1/2 directivity angle of the light source 1. In this simulation, the 1/2 directivity angle θa of the light source 1 in the thickness direction of the light guide plate 3 is used as a variable.

  When the light source 1 is composed only of the LED unit 11 (no condensing lens 12 is provided), as shown in FIG. 8B, the light intensity has a peak at substantially the center Z11 of the directivity angle of the LED element 11b. It becomes. And angle (theta) b between the places Z12 and Z13 in which light intensity becomes half of the light intensity in Z11 becomes a 1/2 directivity angle. When the LED element 11b having a general Lambert light distribution is used, the ½ directivity angle θb is about 120 °, and since the ½ directivity angle θb is wide, the outgoing light from the emission surface 33 tends to increase. Become. Therefore, in the present embodiment, by providing the condensing lens 12, the directivity angle of the light emitted from the LED element 11b is narrowed, and the 1/2 directivity angle θa is set to a desired value. Therefore, even when a general Lambertian light distribution element is used for the LED element 11b, the ½ directivity angle θa of the light source 1 can be set to a desired value, so that the Lambert light distribution element is inexpensive and has high output. Can be used for the LED element 11b.

  The flatness ratio H / R of the prism 34 is a ratio between the height H of the prism 34 and the radius R of the portion where the prism 34 is in contact with the emission surface 33 (see FIG. 5B). The flattened shape H / R becomes smaller as the prism 34 is more crushed in the height direction.

  The lighting fixture using the light guide plate 3 is arranged with the emission surface 32 not provided with the prism 34 facing the irradiation area (illumination target). In this case, the light distribution of the luminaire is such that the amount of front light irradiated from the exit surface 32 not provided with the prism 34 is increased, and the amount of back light irradiated from the exit surface 33 provided with the prism 34 is decreased. It is better to do this.

  Therefore, by simulation using the 1/2 directivity angle θa of the light source 1 and the flatness ratio H / R of the prism 34 as variables, the light distribution of the light guide plate 3 and the ratio of the front light I1 and the back light I2 of the light guide plate 3 are obtained. A certain output ratio I1 / I2 was derived. The front light I1 of the light guide plate 3 is light emitted from the light emission surface 32 to the outside of the light guide plate 3, and the back light I2 of the light guide plate 3 is light emitted from the light emission surface 33 to the outside of the light guide plate 3. That is, as shown in FIG. 9, the front light I <b> 1 is light emitted within a range of a directivity angle of 180 ° with respect to the front direction of the light guide plate 3 (the direction in which the emission surface 32 faces). Further, as shown in FIG. 9, the back light I2 is light emitted within a range of a directivity angle of 180 ° with respect to the back direction of the light guide plate 3 (the direction in which the light emission surface 33 faces). And, as the emission ratio I1 / I2 is larger, the emitted light from the emission surface 32 becomes dominant, and the light distribution as a lighting fixture becomes preferable.

  Furthermore, as shown in FIG. 9, the front light I1 is emitted in the front direction at a deep emission angle with respect to the emission surface 32, and the side light is emitted in the oblique direction at a shallow emission angle with respect to the emission surface 32. Divide into I12. The front light I11 is light emitted from the front light I1 within a range of a directivity angle of 120 ° with respect to the front direction of the emission surface 32. The side light I12 is light that is emitted out of the range of the directivity angle of 120 ° with respect to the front direction of the emission surface 32 in the front light I1. And the light distribution distribution as a lighting fixture becomes preferable, so that the ratio of the front light I11 contained in the front light I1 is large.

  10 (a) and 10 (b) show the arrangements seen from the length direction of the light guide plate 3 (both directions of X11) under the conditions of 1/2 directivity angle θa = 60 ° and flatness H / R = 0.36. It is a simulation result of light distribution. Specifically, FIG. 10A is a light distribution curve diagram that is a simulation result of the light distribution, and FIG. 10B is a conceptual diagram of the simulation result of the light distribution. In FIG. 10A, the numerical values (0.2 to 1.0) of the concentric circles are relative values of luminous intensity, and the same applies to other light distribution curve diagrams. In this case, the emission ratio I1 / I2, which is the ratio between the front light I1 and the back light I2, is large, and the front light I1 (the light emitted from the output surface 32) becomes dominant. Further, of the front light I1, the front light I11 is larger than the side light I12. Therefore, the light distribution is preferable as a lighting fixture.

  Next, FIGS. 11 (a) and 11 (b) are from the length direction of the light guide plate 3 (directions of both ends of X11) under the conditions of 1/2 directivity angle θa = 120 ° and flatness H / R = 0.24. It is the simulation result of the observed light distribution. Specifically, FIG. 11A is a light distribution curve diagram that is a simulation result of the light distribution, and FIG. 11B is a conceptual diagram of the simulation result of the light distribution. In this case, the emission ratio I1 / I2, which is the ratio between the front light I1 and the back light I2, is small, and the back light I2 (the light emitted from the output surface 33) becomes dominant. Further, in the front light I1, the side light I12 is larger than the front light I11. Therefore, the light distribution is inappropriate for a lighting fixture.

  12 and 13 are graphs showing simulation results.

  First, in FIG. 12, the horizontal axis represents the flatness ratio H / R of the prism 34, and the vertical axis represents the emission ratio I1 / I2 which is the ratio of the front light I1 and the back light I2 of the light guide plate 3. In FIG. 12, ◆: 1/2 directivity angle θa ≧ 70 °, ■: 1/2 directivity angle θa = 60 °, ▲: 1/2 directivity angle θa = 40 °, x: 1/2 directivity angle Each data of θa = 20 ° is shown. In FIG. 12, when the 1/2 directivity angle θa is 70 ° or more, the emission ratio I1 / I2 is small (front light I1 is small) over the entire range of the flatness ratio H / R of the prism 34. On the other hand, when the 1/2 directivity angle θa is 60 ° or less, the emission ratio I1 / I2 is improved if the flatness ratio H / R of the prism 34 is in the range of 0.25 or more and 0.50 or less. Thus, the outgoing light from the outgoing surface 32 becomes dominant.

  In FIG. 13, the horizontal axis represents the 1/2 directivity angle θa in the thickness direction of the light guide plate 3, and the vertical axis represents the emission ratio I1 / I2. In FIG. 13, ♦: the flatness ratio H / R of the prism 34 is less than 0.25, ■: the flatness ratio H / R of the prism 34 is 0.25 or more and less than 0.35, and ▲: the flatness of the prism 34 The ratio H / R is 0.35 or more and less than 0.45, and X: the flatness ratio H / R of the prism 34 is 0.45 or more and 0.50 or less. In FIG. 13, when the flatness ratio H / R of the prism 34 is less than 0.25, the emission ratio I1 / I2 is small (the front light I1 is small) over the entire range of the 1/2 directivity angle θa. Further, when the flatness ratio H / R of the prism 34 is 0.25 or more and less than 0.50, the emission ratio I1 / I2 is kept relatively small in the range where the ½ directivity angle θa is 70 ° or more. doing. However, when the flatness ratio H / R of the prism 34 is not less than 0.25 and not more than 0.50, when the 1/2 directivity angle θa is 60 ° or less, the output ratio I1 / I2 is equal to the 1/2 directivity angle θa. As the value becomes smaller, the light emitted from the light emission surface 32 becomes dominant.

  From the simulation results of FIGS. 12 and 13, the 1/2 directivity angle θa in the thickness direction of the light guide plate 3 is 60 ° or less, and the flatness ratio H / R of the prism 34 is 0.25 or more and 0.50 or less. Thus, it can be seen that the light emitted from the light exit surface 32 becomes dominant. Therefore, if the ½ directivity angle θa in the thickness direction of the light guide plate 3 is 60 ° or less and the flatness ratio H / R of the prism 34 is 0.25 or more and 0.50 or less, the light distribution as a lighting fixture is It will be preferable.

  Next, in FIG. 14, the horizontal axis indicates the flatness ratio H / R of the prism 34, and the vertical axis indicates the ratio of the front light I11 in the front light I1. In FIG. 14, ♦: 1/2 directivity angle θa ≧ 70 ° in the thickness direction of the light guide plate 3, ■: 1/2 directivity angle θa = 60 °, ▲: 1/2 directivity angle θa = 40 °, ○: Each data of 1/2 directivity angle θa = 20 ° is shown. When the ½ directivity angle θa in the thickness direction of the light guide plate 3 is 60 ° or less and the flatness H / R of the prism 34 is 0.26 or more and 0.44 or less, the front light I11 in the front light I1 is The ratio is 50% or more, and the amount of front light I11 can be increased.

  In reality, in consideration of the productivity of the condenser lens 12, the accuracy variation of the condenser lens 12, and the light distribution of the light guide plate 3 (ratio of the front light I11), 30 ° ≦ ½ directivity angle θa. It is preferable to set ≦ 60 °, 0.30 ≦ flattening ratio H / R ≦ 0.40.

  15 to 18 show the light distribution of the light guide plate 3 based on simulation results using the 1/2 directivity angle θa of the light source 1 in the thickness direction of the light guide plate 3 and the flatness ratio H / R of the prism 34 as variables. The result of judging the quality of the distribution is shown.

  First, in FIG. 15, the 1/2 directivity angle θa of the light source 1 in the thickness direction of the light guide plate 3 and the flatness ratio H / R of the prism 34 are “θa ≦ 60 °, 0.25 ≦ H / R ≦ 0.50”. A region S1 is shown. By satisfying the ½ directivity angle θa of the light source 1 and the flatness H / R of the prism 34 in this region S1, the light emitted from the light emission surface 32 becomes dominant, and the light distribution as a lighting fixture is preferable. Become a thing. That is, when the prism 34 is provided on the exit surface 33 of the light guide plate 3 by setting the 1/2 directivity angle θa and the flatness ratio H / R within the region S1, the light is emitted from the exit surface 32 of the light guide plate 3. The ratio (light quantity) of light to be increased can be increased.

  Next, FIG. 16 shows that the 1/2 directivity angle θa of the light source 1 in the thickness direction of the light guide plate 3 and the flatness H / R of the prism 34 are “θa ≦ 60 °, 0.26 ≦ H / R ≦ 0.44. A region S2 that becomes “ In this region S2, the ratio of the front light I11 in the front light I1 can be maintained at 50% or more, and the light distribution as a lighting fixture becomes more preferable.

  Next, FIG. 17 shows that the 1/2 directivity angle θa of the light source 1 in the thickness direction of the light guide plate 3 and the flatness H / R of the prism 34 are “30 ° ≦ θa ≦ 60 °, 0.30 ≦ H / R ≦ A region S3 that is 0.40 "is shown. In this region S3, the ½ directivity angle θa of the light source 1 and the flatness ratio H / R of the prism 34 are the productivity of the condenser lens 12, the accuracy variation of the condenser lens 12, the light distribution of the light guide plate 3 (front light). In consideration of the ratio of I11), this is a range that can be practically realized in the region S2. That is, by setting the 1/2 directivity angle θa and the flatness ratio H / R in the region S3, the condenser lens 12 and the prism 34 that can more preferably control the light distribution as a lighting fixture can be easily realized. can do.

  Next, FIG. 18 shows that the 1/2 directivity angle θa of the light source 1 in the thickness direction of the light guide plate 3 and the flatness ratio H / R of the prism 34 are “θa ≦ 60 °, H / R ≦ 0.24” and “60. The region S4 where “° <θa” is shown. In this region S4, the ½ directivity angle θa of the light source 1 and the flatness ratio H / R of the prism 34 are regions that have little effect on the light distribution control so that the emitted light from the emission surface 32 becomes dominant. It is.

  19 and 20 show actual light distributions using the lighting fixtures shown in FIGS. Specifically, FIG. 19A is a cross-sectional view of the lighting apparatus shown in FIGS. 1 to 3 with the light guide plate 3 removed, and FIG. 19B is an arrangement in the state of FIG. FIG. Moreover, Fig.20 (a) is sectional drawing of the lighting fixture shown in FIGS. 1-3, FIG.20 (b) is a light distribution curve figure in the state of Fig.20 (a).

  The light guide plate 3 has a length X1 = 600 mm and a width X2 = 200 mm. In the light source 1, 120 LED elements 11b are arranged on the substrate 11a at intervals of 5 mm. The size of the LED element 11b is 3 mm × 1.4 mm × 0.6 mm. The radius R of the prism 34 is 30 μm, the flatness H / R of the prism 34 is 0.25 or more and 0.50 or less, and the coverage ratio of the prism 34 on the exit surface 33 is 45%. The 1/2 directivity angle θa of the light emitted from the condenser lens 12 is about 35 °. Further, the white tape 5 having a high reflection coefficient is pasted on the other three end surfaces (including the end surface 35) except for the end surface 31 of the light guide plate 3. The input power of the light source 1 is about 30W.

  FIG. 19 shows the light distribution by only the light source 1 with the light guide plate 3 removed. In this case, the light distribution is such that the directivity angle is about 35 °, and the light I3 is irradiated almost uniformly on both the front side and the back side.

  FIG. 20 shows a light distribution when the light guide plate 3 is attached to the light source 1. The condenser lens 12 controls the light distribution of the light emitted from the LED element 11b so that the ½ directivity angle θa in the thickness direction of the light guide plate 3 is 60 ° or less. Further, the flatness ratio H / R of the prism 34 is set in a range of 0.25 ≦ H / R ≦ 0.50. In this case, the light distribution is controlled such that the front light I1 is larger than the back light I2, and the front light I1 (light emitted from the light emission surface 32) is dominant. In addition, the white tape 5 with a high reflection coefficient is stuck on the end surface 35 facing the end surface 31 of the light guide plate 3, and the rear region U <b> 1 of the light source 1 is irradiated with light reflected by the white tape 5.

  As described above, the luminaire is formed of a plate-like translucent member, and has an emission surface 33 (first surface) and an emission surface 32 (second surface) that face each other as an emission surface that emits light. A light guide plate 3 is provided. Further, the luminaire includes a convex curved protrusion made of a translucent resin disposed on the light exit surface 33 of the light guide plate 3 as a prism 34. Furthermore, the lighting fixture includes a light source 1 that makes light incident on an end surface 31 along the thickness direction of the light guide plate 3. The ½ directivity angle θa, which is an angle between portions where the intensity of light output from the light source 1 becomes half of the peak value, is 60 ° or less in the thickness direction of the light guide plate 3. Further, the ratio H / R between the height H of the prism 34 and the radius R of the portion where the prism 34 is in contact with the emission surface 33 of the light guide plate 3 satisfies 0.25 or more and 0.50 or less.

  In addition, as shown in FIG. 21, the acrylic condenser lens 12 may be integrally formed on the end surface 31 of the acrylic light guide plate 3. In this case, since an air layer is not interposed between the condensing lens 12 and the end surface 31 of the light guide plate 3, energy loss (loss of light) at the interface between the condensing lens 12 and the end surface 31 of the light guide plate 3 is reduced. It is suppressed. The condensing lens 12 may be configured to be attached to the end surface 31 of the light guide plate 3 with a translucent adhesive or the like. That is, the condenser lens 12 is preferably provided on the end surface 31 of the light guide plate 3.

(Embodiment 2)
The structure of the lighting fixture of this embodiment is shown in FIG. 22, FIG.

  This luminaire houses two light sources 1 (referred to as light sources 1A and 1B) in a rectangular box-shaped casing 6 (see FIG. 23), and the light sources 1A and 1B oppose each other on the casing 6. Light is output in opposite directions from the surface. The light source 1A and the light guide plate 3A make a pair, the light source 1B and the light guide plate 3B make a pair, and the light guide plate 3 (referred to as light guide plates 3A and 3B) is provided on the mutually opposing surfaces of the housing 6. Each is provided. This lighting fixture is a pendant type lighting fixture that is suspended from the ceiling by a wire 7 attached to the housing 6. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1, and description is abbreviate | omitted.

  And the light distribution of the lighting fixture calculated | required by simulation (The light distribution curve figure seen from the length direction (the both ends direction of X21) of the light-guide plate 3) is shown in FIG. In addition, as a model of the lighting fixture used for this simulation, the length X21 = 600 mm of the light guide plates 3A, 3B, the width X22 = 400 mm of the lighting fixture, and the thickness X23 = 4 mm of the light guide plates 3A, 3B were used. In the light sources 1A and 1B, 120 LED elements 11b are arranged on the substrate 11a at intervals of 5 mm. The size of the LED element 11b is 3 mm × 1.4 mm × 0.6 mm. Further, the radius R of the prism 34 is 30 μm, the flattening ratio H / R of the prism 34 is a value of 0.25 or more and 0.50 or less, and the coverage ratio of the prism 34 on each of the light exit surfaces 33 of the light guide plates 3A and 3B is 45%. And The 1/2 directivity angle θa of the light emitted from the condenser lens 12 is about 35 °. In the light guide plates 3A and 3B, white tape having a high reflection coefficient is pasted on the other three end surfaces (including the end surface 35) other than the end surface 31 to which the light sources 1A and 1B are attached. The sum of the input powers of the light sources 1A and 1B is about 60W.

  As shown in FIG. 24, the light distribution of this lighting fixture is a broad light distribution in which the front light I1A of the light guide plate 3A and the front light I1B of the light guide plate 3B are irradiated downward over a wide range. . Further, the back light I2A of the light guide plate 3A and the back light I2B of the light guide plate 3B are irradiated upward over a wide range, and light distribution illuminates the ceiling widely.

  Usually, in the case of a lighting fixture using a light guide plate, light distribution control or the like is performed using a light diffusion sheet, a reflection plate, or the like for the light guide plate. However, in this lighting fixture, the light diffusing sheet and the reflecting plate are not required by setting the characteristics of the condenser lens 12 and the shape of the prism 34 in the same manner as in the first embodiment. Due to the light property, it has excellent decorativeness (especially when not lit).

(Embodiment 3)
The lighting fixture of this embodiment is provided with the structure shown to FIG. 22, FIG. 23 similarly to Embodiment 2. FIG. However, this lighting fixture has a lighting fixture width X22 = 200 mm. Other configurations are the same as those of the second embodiment, and the same components are denoted by the same reference numerals and description thereof is omitted.

  And this lighting fixture performs the light distribution design suitable for the kind of lighting fixture by mixing and using the some prism 34 from which flatness H / R mutually differs, and shows a simulation result below.

  The prism 34 has a flatness ratio H / R = “0.40”, “0.38”, “0.36”, “0.34”, “0.32”, and “0.30”. Reference numerals 34a, 34b, 34c, 34d, 34e, and 34f are given. Each light distribution of the lighting fixture when using the prisms 34a, 34b, 34c, 34d, 34e, 34f (light distribution curve diagram viewed from the length direction of the light guide plate 3 (both ends of X21)) 25 (a) to (f). As the flatness ratio H / R is higher, the light distribution range by the front light I1A of the light guide plate 3A and the light distribution range by the front light I1B of the light guide plate 3B are closer to each other. Further, as the flatness ratio H / R is lower, the light distribution range by the front light I1A of the light guide plate 3A and the light distribution range by the front light I1B of the light guide plate 3B are separated from each other.

  Then, by using a mixture of the prism 34a having a flat rate H / R = 0.40 and the prism 34b having a flat rate H / R = 0.38, the narrow-angle light distribution shown in FIG. 26 can be realized. FIG. 26 shows a light distribution of a lighting fixture (a light distribution curve diagram viewed from the length direction of the light guide plate 3 (both ends of X21)) when the prism 34a and the prism 34b are mixed and used. Note that the mixing ratio of the prism 34a with a flatness ratio H / R = 0.40 is 80%, and the mixing ratio of the prism 34b with a flatness ratio H / R = 0.38 is 20%. In the light distribution shown in FIG. 26, each light distribution range by the front light I1A of the light guide plate 3A and the front light I1B of the light guide plate 3B is within a relatively narrow range below the luminaire, realizing a narrow angle light distribution. Yes. Furthermore, each light distribution range by the back light I2A of the light guide plate 3A and the back light I2B of the light guide plate 3B is also within a relatively narrow range above the luminaire, thereby realizing a narrow angle light distribution.

  Further, a prism 34a having an aspect ratio H / R = 0.40, a prism 34b having an aspect ratio H / R = 0.38, and a prism 34f having an aspect ratio H / R = 0.30 are mixed and used. The wide-angle light distribution shown in FIG. 27 can be realized. FIG. 27 shows a light distribution of a lighting fixture (light distribution curve diagram viewed from the length direction of the light guide plate 3 (both ends of X21)) when the prism 34a, the prism 34b, and the prism 34f are mixed. Show. It is to be noted that the mixing ratio of the prism 34a having an aspect ratio H / R = 0.40 is 70%, the mixing ratio of the prism 34b having an aspect ratio H / R = 0.38 is 10%, and the prism 34f having an aspect ratio H / R = 0.30. The mixing ratio is 20%. In the light distribution shown in FIG. 27, each light distribution range by the front light I1A of the light guide plate 3A and the front light I1B of the light guide plate 3B extends to a relatively wide range below the luminaire, thereby realizing wide-angle light distribution. . Furthermore, each light distribution range by the back light I2A of the light guide plate 3A and the back light I2B of the light guide plate 3B is also expanded to a relatively wide range above the lighting fixture, thereby realizing a wide angle light distribution.

(Embodiment 4)
The structure of the lighting fixture of this embodiment is shown in FIG. 29, FIG. The basic configuration is the same as that of the second embodiment, but is different from the second embodiment in that the light guide plates 3A and 3B are inclined, and the same components are denoted by the same reference numerals and description thereof is omitted.

  The lighting fixture of the present embodiment is a pendant type lighting fixture suspended from the ceiling 101. And the light radiate | emitted below from the output surface 32 of light-guide plate 3A, 3B irradiates the floor surface 100, and the light radiate | emitted upward from the output surface 33 irradiates the ceiling 101 (refer FIG. 30). That is, the emission surface 32 has the floor surface 100 as an irradiation surface, and the emission surface 33 has the ceiling 101 as an irradiation surface.

  As shown in FIG. 31A, when the light guide plates 3A and 3B are arranged without being inclined so that the plate surfaces of the light guide plates 3A and 3B are on the same plane (an inclination angle θ1 = 0 ° described later), illumination is performed. The light distribution of the instrument (light distribution curve diagram viewed from the length direction of the light guide plate 3 (the direction of both ends of X21)) is as shown in FIG. 31A and 31B, the front lights I1A and I1B (front lights I11A and I11B and side lights I12A and I12B) of the light guide plates 3A and 3B are inclined in the light emitting direction of the light source 1. Therefore, when used as a pendant-type lighting fixture, the component of the light in the vertical direction (direct light) irradiated perpendicularly to the floor surface 100 is relatively small. It is desirable that the light distribution below in the pendant type luminaire increases the component of the direct light.

  31A and 31B, the back light I2A of the light guide plate 3A and the back light I2B of the light guide plate 3B have an emission angle θc of about 15 ° to 20 ° with respect to the reference surface 110 parallel to the floor surface 100. Become. As for the upper light distribution in the pendant-type lighting fixture, it is desirable that the emission angle θc of the back light I2A, I2B is close to 0 °, and the light is distributed upward with the smallest possible emission angle θc.

  Therefore, in the present embodiment, the end surface 35 of the light guide plates 3A and 3B approaches each other in order to increase the components of the direct light included in the front light I1A and I1B and to make the emission angle θc of the back light I2A and I2B close to 0 °. (See FIGS. 30 and 32 (a)). Specifically, in the light guide plates 3A and 3B, the light source 1 is attached to an end surface 31 (first end surface), and an end surface 35 is formed to face the end surface 31 (see FIG. 1). The light guide plates 3 </ b> A and 3 </ b> B are installed to be inclined so that the end surface 35 is closer to the floor surface 100 than the end surface 31. That is, each end surface 35 of the light guide plates 3A and 3B is inclined downward so as to approach each other. The inclination angle of the light guide plates 3A and 3B with respect to the reference plane 110 is referred to as θ1.

  32A, when the light guide plates 3A and 3B are inclined and arranged so that the end faces 35 of the light guide plates 3A and 3B are close to each other (as an example, when the inclination angle θ1 = 10 °), The light distribution is shown as in FIG. The light distribution shown in FIG. 32B is a light distribution curve diagram viewed from the length direction of the light guide plate 3 (the both end directions of X21).

  Hereinafter, the setting of the inclination angle θ1 of the light guide plates 3A and 3B with respect to the reference surface 110 and the flatness H / R of the prism 34 will be described.

First, the inclination angle θ1 of the light guide plates 3A and 3B is:
(Condition 1) The emission angle θc of the back light I2A and I2B is brought close to 0 °.
(Condition 2) The component of the direct light from the front light I1 is increased.
The two conditions are set.

(Condition 1)
When the inclination angle θ1 of the light guide plates 3A and 3B is 0 °, the emission angle θc of the back light I2A and I2B is about 15 ° to 20 ° (see FIGS. 25A to 25F). Therefore, in order to make the emission angle θc of the back light I2A, I2B close to 0 °, the inclination angle θ1 of the light guide plates 3A, 3B may be set to 5 ° -25 °. That is, the inclination angle θ1 that satisfies (Condition 1) is
5 ° ≦ θ1 ≦ 25 ° ……… (Formula 1)
It becomes.

(Condition 2)
As shown in FIG. 33, when the inclination angle θ1 of the light guide plates 3A and 3B is gradually increased from 0 °, the intensity of the light output from the light source 1 becomes the half of the peak value (0.5 times). An inclination angle θ1 at which the portion Za faces directly below is defined as a lower limit inclination angle θ11. Further, the inclination angle θ1 is gradually increased, and the inclination angle θ1 at which the second portion Zb at which the intensity of the light output from the light source 1 is 0.9 times the peak value faces directly below is defined as the upper limit inclination angle θ12. . Then, FIG. 34 shows values of the lower limit inclination angle θ11 and the upper limit inclination angle θ12 derived for each light distribution in FIGS. 25 (a) to 25 (f). 25A to 25F, the flatness ratio H / R of the prism 34 is “0.40”, “0.38”, “0.36”, “0.34”, “ Corresponding to “0.32” and “0.30”.

  FIG. 35 is a graph showing the lower limit inclination angle θ11 and the upper limit inclination angle θ12 with the flatness ratio H / R as a variable.

The lower limit inclination angle θ11 is expressed as θ11 = −250 · (H / R) +100, and the upper limit inclination angle θ12 is expressed as θ12 = −335.7 · (H / R) +149.2. And the inclination angle θ1 satisfying (Condition 2) is
−250 · (H / R) + 100 ≦ θ1 ≦ −335.7 · (H / R) +149.2 (Equation 2)
It becomes.

The inclination angle θ1 that satisfies the above (formula 1) and (formula 2) satisfies both the above (condition 1) and (condition 2). That is, the inclination angle θ1 is
−250 · (H / R) + 100 ≦ θ1 ≦ −335.7 · (H / R) +149.2 However, 0.30 ≦ (H / R) ≦ 0.43 (Equation 3)
Should be satisfied. FIG. 35 shows a region 120 that satisfies (Equation 3).

  Thus, the light distribution of the lighting fixture in which the inclination angle θ1 of the light guide plates 3A and 3B and the flatness H / R of the prism 34 satisfy (Equation 3) is as shown in FIGS. 32 (a) and 32 (b). The emission angle θc of the back light I2A, I2B can be made close to 0 °. Further, the front light I1A, I1B (front light I11A, I11B, side light I12A, I12B) of the light guide plates 3A, 3B decreases the degree of inclination of the light source 1 in the light emission direction and increases the component of the direct light. Can do. In particular, the front lights I11A and I11B are emitted in the vertical direction (including the substantially vertical direction).

  That is, in the lighting fixture, when the inclination angle θ1 of the light guide plates 3A and 3B and the flatness ratio H / R of the prism 34 satisfy the above (Equation 3), the emission angle θc of the back light I2A and I2B approaches 0 °. Thus, it is possible to distribute light at an angle as shallow as possible. Furthermore, the lighting fixture can increase the component of the direct light by satisfying the above (Equation 3) by the inclination angle θ1 of the light guide plates 3A and 3B and the flatness H / R of the prism 34.

  Next, as shown in FIG. 36, the reflecting member 8 that reflects the back lights I2A and I2B emitted from the emission surfaces 33 of the light guide plates 3A and 3B may be provided to face the emission surface 33. In this case, the reflected light of the reflecting member 8 is emitted from the emission surface 32 as front light I1A and I1B. Therefore, in the lighting fixture of FIG. 36, the inclination angle θ1 is set based only on the light distribution of the front lights I1A and I1B emitted from the emission surface 32.

First, the inclination angle θ1 of the light guide plates 3A and 3B is:
(Condition 3) The direct light component of the front light I1 is increased.
It is set from the condition.

(Condition 3)
The lower limit inclination angle θ11 and the upper limit inclination angle θ12 derived for each light distribution in FIGS. 25A to 25F are shown in FIG.

  Next, FIG. 37 is a graph showing the lower limit inclination angle θ11 and the upper limit inclination angle θ12 with the flatness ratio H / R as a variable.

The lower limit inclination angle θ11 is expressed as θ11 = −250 · (H / R) +100, and the upper limit inclination angle θ12 is expressed as θ12 = −335.7 · (H / R) +149.2. And the inclination angle θ1 satisfying (Condition 3) is
−250 · (H / R) + 100 ≦ θ1 ≦ −335.7 · (H / R) +149.2 (Equation 4)
It becomes.

  In this lighting fixture, the flatness H / R of the prism 34 is set to 0.25 or more and 0.50 or less in order to make the emitted light from the emission surface 32 dominant, and the range of this flatness H / R Of these, the inclination angle θ1 may satisfy the above (Equation 4).

That is, the inclination angle θ1 is
−250 · (H / R) + 100 ≦ θ1 ≦ −335.7 · (H / R) +149.2 However, 0.25 ≦ (H / R) ≦ 0.50 (Formula 5)
Should be satisfied. FIG. 37 shows a region 130 that satisfies (Equation 5).

  The lighting fixture can increase the component of the direct light by satisfying the above (Equation 5) by the inclination angle θ1 of the light guide plates 3A and 3B and the flatness ratio H / R of the prism 34.

  Further, as shown in FIG. 38, also in a lighting fixture using only one light guide plate 3, by setting the inclination angle θ1 of the light guide plate 3 and the flatness ratio H / R of the prism 34 in the same manner as described above, The effect of can be obtained.

  Further, in each of the above-described embodiments, instead of the condensing lens 12 constituted by the TIR lens, the condensing lens 13 made of resin disposed on the surface of the LED element 11b as shown in FIG. Also good. Alternatively, as shown in FIG. 28B, a condensing lens 14 made of a sealing resin in which the periphery of the LED element 11b is sealed on the substrate 11a may be used. The condenser lenses 13 and 14 are formed in, for example, a hemispherical dome shape.

  In each of the above-described embodiments, the prism 34 is provided only on the exit surface 33 of the light guide plate 3. However, the prism 34 is provided on the exit surface 32 and the prisms 34 are provided on both sides of the light guide plate 3. But you can. Then, by individually setting the shape, coverage, arrangement pattern, etc. of the prism provided on the exit surface 32 and the prism provided on the exit surface 32, the exit surface 32 side and the exit surface 33 side are individually desired. Can be obtained.

DESCRIPTION OF SYMBOLS 1 Light source 11 LED unit 12 Condensing lens 3 Light guide plate 31 End surface 32, 33 Output surface 34 Prism

Claims (8)

A light guide plate formed of a plate-like light-transmitting member and having a first surface and a second surface facing each other as an output surface for emitting light, and a light transmission disposed on the first surface of the light guide plate And a light source that makes light incident on the first end surface along the thickness direction of the light guide plate,
The 1/2 directivity angle, which is an angle between locations where the intensity of light output from the light source becomes half of the peak value, is 60 ° or less in the thickness direction of the light guide plate,
The ratio H / R between the height H of the protrusion and the radius R of the portion where the protrusion contacts the first surface of the light guide plate satisfies 0.25 or more and 0.50 or less. lighting equipment. The light source is
A light emitting element that emits light;
Light emitted by the light emitting element is provided between the light emitting element and the first end face of the light guide plate so that the ½ directional angle is 60 ° or less in the thickness direction of the light guide plate. The illuminating device according to claim 1, comprising: a condenser lens that controls light distribution.   The lighting apparatus according to claim 2, wherein the condensing lens is provided on the first end face of the light guide plate.   The lighting apparatus according to claim 3, wherein the condensing lens includes a concave portion that houses the light source, and a reflective surface that extends from a peripheral edge of the concave portion to an outer edge of the first end surface of the light guide plate. .   A ratio H / R between a height H of the protrusion and a radius R of the portion where the protrusion contacts the first surface of the light guide plate satisfies 0.26 or more and 0.44 or less. The lighting fixture in any one of Claims 1 thru | or 4.   The light guide plate has a second end face opposite to the first end face, and the second end face from the first end face with respect to the irradiation face irradiated with light emitted from the second face. The angle θ1 at which the light guide plate is inclined with respect to a reference plane parallel to the irradiation surface satisfies an angle of 5 ° or more and 25 ° or less. The lighting fixture in any one of thru | or 5. The ratio H / R between the height H of the protrusion and the radius R of the portion where the protrusion contacts the first surface of the light guide plate satisfies 0.30 or more and 0.43 or less,
The angle θ1 at which the light guide plate is inclined with respect to the reference plane satisfies −250 · (H / R) + 100 ≦ θ1 ≦ −335.7 · (H / R) +149.2. 6. The lighting fixture according to 6.   The lighting fixture according to claim 6, wherein a reflection member that reflects light emitted from the first surface of the light guide plate is provided to face the first surface.

Images