JP6012972B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device.

  As the luminous efficiency of LEDs (Light Emitting Diodes) has improved, lighting devices such as light bulb shaped lamps, lighting units, and lighting fixtures that use LEDs as light sources have begun to spread. However, since the LED has a strong directivity, it is difficult to irradiate light uniformly when the LED is used as a light source. In particular, in the case of LED lighting installed on a ceiling surface or wall surface, it can illuminate the lower or front side, but it cannot illuminate the mounting surface such as the ceiling or wall, so it is sufficient for illumination. There are many cases where it cannot be said. For example, in order to illuminate the mounting surface in order to illuminate the mounting surface, it is necessary to attach a reflection plate or the like to the illumination device, which is complicated and expensive.

  In recent years, lighting fixtures in which a large number of LEDs are arranged have been proposed in response to demands for higher brightness and higher power of LED lighting. For example, Patent Document 1 discloses an LED lamp capable of illuminating a wide range by mounting a plurality of LEDs on a plurality of substrates and arranging the substrates on a plurality of surfaces having different normals. Yes.

JP 2010-135308 A

  However, in the case of a luminaire in which a large number of LEDs are arranged, it is necessary to provide a diffusion cover such as a globe at a position away from the LEDs so that the difference in brightness between the LEDs is not noticeable. Therefore, a lighting fixture will become large sized. Further, since a certain distance from the LED to the diffusion cover is required, it is difficult to make the lighting fixture thin.

Therefore, an object of the present invention is to provide an illumination device that can perform wide light distribution (wide range of light distribution) and can be thinned.

In order to achieve the above object, the present invention introduces a light source installed on a substrate and a light source that is arranged on the same side of the substrate as the light source with the light source interposed therebetween and allows the light from the light source to pass therethrough. In a lighting device having a light body, a transmittance adjusting member that has a sloped shape on the side opposite to the light source of the light guide, transmits a part of the light passing through the light guide, and reflects most of the light The transmittance adjusting member is characterized in that a high transmittance portion is formed by forming a hole in a part thereof, and a low transmittance portion is formed by a portion other than the hole. To do.

  The light guide is preferably a light scattering light guide that is formed by dispersing light scattering particles in a transparent resin material and generates volume scattering. By volume scattering by the light scattering light guide, light beams having various angles can be emitted, and uniform and non-uniform illumination can be obtained.

  The light guide is preferably a surface-scattering light-guide that is formed of a transparent resin material and has an exit surface that generates surface scattering by roughening or the like. By surface scattering due to the roughening of the emission surface, light beams having various angles can be emitted, and uniform illumination without unevenness can be achieved.

  The light guide is one of a columnar shape, a line shape, and a circle shape.

A plurality of light sources on the substrate are arranged at intervals on a plurality of circumferences having a common center, and the light guide has a light guide portion formed in an annular shape along each circumference, The slope of each light guide section is inclined upward from the inside to the outside, the transmittance adjusting member is disposed on the slope, and the light guide is disposed outside the height of the light guide section disposed on the inside. The height of the portion can be increased, and a groove or a through-hole can be formed between the annular light guide portion so as to open upward, thereby forming a high transmittance portion of the transmittance adjusting member .

  According to the present invention, the lateral direction of the light source can be illuminated in addition to the front surface of the light source. Accordingly, it is possible to provide an illumination device capable of wide light distribution. In addition, since a structure in which a large amount of light is reflected and directed in the lateral direction or the backward direction is provided, a thin illuminating device can be provided.

It is a perspective view of the illuminating device which concerns on 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the state which removed the diffusion cover from the illuminating device of FIG. FIG. 2 is a diagram illustrating a traveling direction (optical path) of light incident on a light guide from an LED serving as a light source in the illumination device of FIG. 1, and (a) illustrates a progression of light incident on the light guide substantially vertically upward. FIG. 5B is a diagram illustrating a traveling direction of light incident on the light guide body in the diagonally right direction, and FIG. 5C is a diagram illustrating a traveling direction of light incident in the diagonally left direction on the light guide body. . In the illuminating device of FIG. 1, it is a figure which shows light distribution in case a light guide is a transparent material, (a) is an illuminance distribution map, (b) is a light distribution map. When the light guide is a light scattering light guide that generates volume scattering, it is a diagram showing the scattering principle of the silicone particles that are the light scattering particles contained therein, the angle of the scattered light intensity by a single spherical particle It is a graph which shows distribution (Α, Θ). It is a figure which shows light distribution of an example in case the light guide of the illuminating device which concerns on 2nd Embodiment of this invention is a light-scattering light guide which generate | occur | produces volume scattering, (a) is an illuminance distribution map, (b) ) Is a light distribution map. It is a figure which shows light distribution of the other example in case the light guide of the illuminating device which concerns on 2nd Embodiment of this invention is a light-scattering light guide which generate | occur | produces volume scattering, (a) is an illuminance distribution map, (B) is a light distribution map. It is a figure which shows light distribution in case the light guide of the illuminating device which concerns on 3rd Embodiment of this invention is a light-scattering light guide which generate | occur | produces surface scattering, (a) is an illuminance distribution map, (b) is It is a light distribution map. It is a perspective view which shows the illuminating device of 4th Embodiment which is a modification of 1st to 3rd embodiment. It is a perspective view which shows the illuminating device which concerns on 5th Embodiment of this invention. It is a perspective view of the state which removed the diffusion cover of the illuminating device which concerns on 6th Embodiment of this invention. It is a longitudinal cross-sectional view of the illuminating device shown in FIG. FIG. 13 is a simplified end view of FIG. 12. 11 and 12 are diagrams showing the traveling direction of light incident on the light guide from the LED with respect to the right part in the illumination device shown in FIGS. FIG. 5B is a diagram illustrating a traveling direction of light incident on the light guide body in the diagonally right direction, and FIG. 5C is a diagram illustrating a traveling direction of light incident in the diagonally left direction on the light guide body. . It is a figure which shows light distribution in case the light guide of 6th Embodiment is a transparent material, (a) is an illuminance distribution map, (b) is a light distribution map. The figure which shows light distribution of an example in case the light guide of 6th Embodiment is a light-scattering light guide which generate | occur | produces volume scattering, (a) is an illuminance distribution map, (b) is a light distribution map. . The figure which shows light distribution of the other example in case the light guide of 6th Embodiment is a light-scattering light guide which generate | occur | produces volume scattering, (a) is an illuminance distribution figure, (b) is light distribution. There is a figure. It is a figure which shows illumination intensity distribution in case the light guide of 6th Embodiment is a surface scattering light guide which generate | occur | produces surface scattering. In the illuminating device which concerns on 7th Embodiment of this invention, it is a figure which shows the advancing direction of the light which injects into a light guide from LED, Comprising: (a) is the progress of the light which injects into a light guide substantially vertically upward direction. FIG. 5B is a diagram illustrating a traveling direction of light incident on the light guide body in the diagonally right direction, and FIG. 5C is a diagram illustrating a traveling direction of light incident in the diagonally left direction on the light guide body. . It is a perspective view which shows the illuminating device which concerns on 8th Embodiment of this invention. It is a longitudinal cross-sectional view of the illuminating device shown in FIG. It is the perspective view which shows the illuminating device which concerns on 9th Embodiment of this invention, and is the figure which showed the overlap part transparently and black. It is the perspective view which shows the illuminating device which concerns on 10th Embodiment of this invention, and is the figure which showed the overlap part transparently and black.

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

[First embodiment]
As illustrated in FIGS. 1 and 2, the illumination device A1 according to the first embodiment includes an LED 2 serving as a light source installed on the substrate 1, a light guide 3 provided on the same side as the LED 2, and a light guide. It is comprised from the transmittance | permeability adjustment member 4 provided in the surface on the opposite side to the light source 2 of the light body 3. As shown in FIG. The illumination device A1 is surrounded by a resin-made colored, for example, white diffusion cover (glove) C. In FIG. 2, the diffusion cover C and the substrate 1 are omitted.

  The light source may be any of an incandescent bulb, a fluorescent lamp, an EL (Electro luminescence), and an LED, but in particular, since the LED has directivity, it is difficult to obtain an illumination device with a wide light distribution. Therefore, in the following, a preferred embodiment for achieving a wide light distribution when an LED is used as a light source will be described.

  1 and 2 show only one LED 2 for simplification of the drawings, but a plurality of LEDs 2 are circularly arranged on the substrate 1 with a predetermined uniform interval according to the illuminance required for the illumination device. You may make it arrange | position in a shape, linear form, or another shape. The LED 2 is connected to an electric circuit (not shown) provided in the substrate 1 and the like. When power is supplied to the electric circuit, the LED 2 emits light upward (= y direction) in FIG. It has become.

The light guide 3 in the first embodiment is made of a transparent resin in a prismatic shape, and the upper surface 31 on the opposite side to the LED 2 is formed in a slope shape. The transmittance adjusting member 4 is provided on the inclined upper surface 31. This inclined surface is inclined upward from the inside to the outside, and specifically has an inclination angle α of 45 degrees with respect to the surface of the substrate 1. The inclination angle α is preferably 45 degrees, but may be appropriately changed depending on the required illuminance distribution and light distribution.

  The transmittance adjusting member 4 has a portion with a high transmittance and a portion with a low transmittance. The portion with high transmittance may be the transmission portion 41 having a transmittance of 100 percent by making a hole in the portion, and the portion with low transmittance may be the reflection portion 42 having a reflectance of approximately 100 percent.

  In the first embodiment, the transmittance adjusting member 4 itself is formed of a white highly reflective polycarbonate material, and is welded to the upper surface 31 of the light guide 3 to form the reflecting portion 42. In a certain place, the transparent portion 41 is formed by exposing the upper surface of the light guide 3 without welding a white highly reflective polycarbonate material. The transmitting portion 41 is circular, but may have other shapes.

  With the above configuration, when the LED 2 emits light, the light guide 3 transmits the light of the LED 2 and guides it to the transmittance adjusting member 4, and also reflects the light reflected by the reflecting portion 42 of the transmittance adjusting member 4 of the light guide 3. The light is emitted from the side surface 32 having a higher height.

  FIG. 3 schematically shows light rays that enter the light guide 3 from the LED 2, pass through the light guide 3, and exit from the upper surface 31 or the side surface 32. An illuminance distribution diagram according to the first embodiment is shown in FIG. 3, the right direction of the LED 2 is the z direction, the upper direction is the y direction, and the direction perpendicular to the paper surface is the x direction. This relationship is the same in FIG.

  FIG. 3A shows the traveling direction of the light beam Li1 incident on the light guide 3 at an angle close to vertical among the light beams emitted from the LED 2. The light beam Li1 that has entered the light guide 3 is reflected by the reflecting portion 42 of the transmittance adjusting member 4 and spreads in the lateral direction, and is emitted from the side surface 32 of the light guide 3, and is outside the light guide 3. The light beam Lo1 illuminates the horizontal direction (= z direction in FIGS. 2 and 3). The light beam that has reached the transmission part 41 is also totally reflected by the upper surface 31 of the light guide 3 due to the incident angle, and is emitted from the side surface 32 of the light guide 3 as a light beam spread in the lateral direction. Most of the light rays Lo1 are divided into a front side region B1 which is a region on the side from which the light of the LED 2 is emitted and a back side region B2 on the opposite side by using the reference surface B as a reference surface B. At this time, the light is emitted to the front side region B1. However, a part of the light beam Lo1 enters the back side region B2 which is opposite to the front side region B1.

  FIG. 3B shows a state in which the light beam Li2 incident on the light guide 3 is totally reflected by the side surface 32 at an angle spread obliquely toward the side surface 32 having the higher height among the light beams emitted from the LED 2. ing. The light beam totally reflected by the side surface 32 of the light guide 3 is reflected and spreads downward by the reflecting portion 42 toward the side surface 32, and is emitted from the side surface 32 of the light guide 3. It is a light beam Lo2 that illuminates the direction (the direction toward the back side region B2 in the mounting surface direction of the illumination device A1). Further, the light beam reaching the transmission part 41 is emitted from the transmission part 41 as it is depending on the incident angle and becomes a light beam Lo2 ′ that illuminates the upper direction of the light guide 3. However, the amount of transmission is small, and most of the light transmission part 41 It becomes a light beam Lo2 that is reflected by 41 and illuminates the outer lower side of the light guide 3.

  FIG. 3C shows a state in which the light beam Li <b> 3 incident on the light guide body 3 is totally reflected by the side surface 33 at an angle spread obliquely toward the side surface 33 having the lower height among the light beams emitted from the LED 2. ing. A part of the light rays totally reflected by the side surface 33 of the light guide 3 reaches the reflection portion 42 and is reflected by the reflection portion 42 and illuminates the front side region B1 and spreads upward. 3 is emitted as a light beam Lo3 1 from the side surface 32 having a higher height. In addition, some of the light rays totally reflected by the side surface 33 reach the side surface 32 and are totally reflected again, reach the reflecting portion 42, and are reflected again there to be emitted as light rays spreading downward. Thus, the light beam Lo32 illuminates the lower direction outside the light guide 3 (back side region B2). Further, the light beam reaching the transmission part 41 is totally reflected by the upper inclined surface 31 of the light guide 3, which also spreads upward and becomes a light beam Lo 3 1 emitted from the side surface 32 of the light guide 3.

  Actually, the light beams Li1, Li2, and Li3 in FIGS. 3A, 3B, and 3C are simultaneously generated. Thereby, an illuminance distribution as shown in FIG. 4 can be obtained, and illumination with a wide light distribution can be obtained. 4 is an illuminance distribution diagram when the light guide 3 is a transparent material such as PET (polyethylene terephthalete), PP (polypropylene), PC (polycarbonate), and PMMA (polymethyil methacrylate). The substantially central view of (a) is an illuminance distribution diagram observed from the upper surface of the light guide 3, that is, the illuminance distribution at a position corresponding to the upper surface of the diffusion cover C. It is the irradiation pattern figure in the state where it is arranged and the side 33 side is arranged in the horizontal direction on the upper side of the figure. The vertical and horizontal units are “mm”. 4A is an illuminance distribution graph measured along the vertical center line (z direction in FIG. 3), and the lower graph in FIG. 4A is the horizontal center line (FIG. 3). It is an illuminance distribution graph measured along (x direction). The intersection of both lines is the center of the LED 2. From these illuminance distribution diagrams and illuminance distribution graphs, there is a portion with high illuminance on the side closer to the side surface 32 of the upper surface 31 than the center of the upper surface 31 of the light guide 3, and the illuminance is slightly higher on the side closer to the side surface 33 of the upper surface 31. You can see that there is a part.

  4 (b), starting from the y direction of LED 2, in FIG. 2, each direction over 180 degrees (−180 degrees) in the clockwise direction and each direction over 180 degrees (+180 degrees) in the counterclockwise direction in FIG. It is the graph showing the illuminance distribution seen from. That is, the lowermost part of FIG. 4B is “0 degree”, which indicates the illuminance when viewed from the vertically upper side of the LED 2 of FIG. 2, and is very dark. The brightest direction is minus 110 degrees, the direction of arrow C1 in FIG. 2, the next brightest is minus 145 degrees, the direction of arrow C2 in FIG. 2, the third brightest is minus 80 degrees, and the arrow in FIG. C3 direction. Thus, the light rays (arrow C1 direction, arrow C2 direction) heading toward the back region B2 are increased.

  The directivity of the highly directional light from the LED 2 is considerably relaxed by the internal reflection of the light guide 3 at various angles. However, as shown in FIG. appear. On the other hand, by mounting the diffusion cover C surrounding the light guide 3 on the substrate 1, it is possible to obtain illumination light having considerable isotropy, that is, illumination light that is fairly uniform with little contrast.

  Even when the diffusion cover C is not installed, the light distribution is widened. This is illustrated in FIG. 4 (b). This is because in FIG. 4B, as described above, the light in the lateral direction and the backward direction (= −80 degrees to −145 degrees) is increased. Further, as shown in FIG. 4A, the brightness is considerably high when viewed from above.

[Second Embodiment]
In the second embodiment, the light guide 3 of the first embodiment is a light scattering light guide in which a large number of spherical and translucent light scattering fine particles are contained as transparent fine particles in a transparent resin. Examples of the transparent resin used for the light scattering light guide include optically transparent resins such as PET, PP, PC, and PMMA. As the light scattering fine particles, silicone, silica or the like having a particle diameter of 1 to 10 μm can be used.

  About a light-scattering light guide, it describes in paragraphs 0025-0042 of Unexamined-Japanese-Patent No. 2011-141964, and paragraphs 0017-0034 of Unexamined-Japanese-Patent No. 2011-249141.

  Hereinafter, the silicone particles contained in the light guide 3 will be described. This silicone particle is a light guide provided with a volumetric uniform scattering ability, and includes a large number of spherical particles as scattering fine particles. When light enters the inside of the light guide 3, the light is scattered by the scattering fine particles.

  Here, the Mie scattering theory that gives the theoretical basis of the silicone particles will be described. Mie scattering theory is the solution of Maxwell's electromagnetic equation for the case where spherical particles (scattering fine particles) having a refractive index different from that of the medium exist in a medium (matrix) having a uniform refractive index. . The intensity distribution I (Α, Θ) depending on the angle of the scattered light scattered by the scattering fine particles corresponding to the light scattering particles is expressed by the following equation (1). Α is a size parameter indicating the optical size of the scattering fine particles, and is an amount corresponding to the radius r of the spherical particles (scattering fine particles) normalized by the wavelength λ of light in the matrix. The angle Θ is a scattering angle, and the same direction as the traveling direction of incident light is Θ = 180 °.

  Further, i1 and i2 in the formula (1) are represented by the formula (4). And a and b with subscript ν in the expressions (2) to (4) are expressed by the expression (5). P (cos Θ) with superscript 1 and subscript ν is Legendre's polynomial, a and b with subscript ν are first-order and second-order Recati-Bessel functions Ψ *, ζ * (where “*” Means the subscript ν) and its derivative. m is the relative refractive index of the scattering fine particles based on the matrix, and m = nscatter / nmattrix.

  FIG. 5 is a graph showing the intensity distribution I (Α, Θ) by a single true spherical particle based on the above equations (1) to (5). FIG. 5 shows an angular distribution I (Α, Θ) of scattered light intensity when there is a true spherical particle as a scattering fine particle at the position of the origin G and incident light is incident from below. And the distance from the origin G to each curve S1-S3 is the scattered light intensity | strength of each scattering angle direction. Curve S1 shows the scattered light intensity when Α is 1.7, curve S2 shows the scattered light intensity when Α is 11.5, and curve S3 shows the scattered light intensity when Α is 69.2. Yes. In FIG. 5, the scattered light intensity is shown on a logarithmic scale. For this reason, the portion that appears as a slight difference in intensity in FIG. 5 is actually a very large difference.

  As shown in FIG. 5, the larger the size parameter Α is (the larger the particle size of the true spherical particle is when considered at a certain wavelength λ), the more directivity is upward (front of the irradiation direction). It can be seen that light is highly scattered. Actually, the angle distribution I (Α, Θ) of the scattered light intensity is controlled by using the radius r of the scatterer and the relative refractive index m of the medium and the scattered fine particles as parameters if the incident light wavelength λ is fixed. can do. In addition, the light guide 3 has a large forward scattering.

  When light is incident on such a light scattering light guide containing N single spherical particles, the light is scattered by the spherical particles. Scattered light travels through the light scattering light guide and is again scattered by other spherical particles. When particles are added at a volume concentration of a certain level or more, such scattering is sequentially performed a plurality of times, and then light is emitted from the light scattering light guide. A phenomenon in which such scattered light is further scattered is called a multiple scattering phenomenon. In such multiple scattering, analysis by a ray tracing method with a transparent polymer is not easy. However, the behavior of light can be traced by the Monte Carlo method and its characteristics can be analyzed. According to this, when the incident light is non-polarized light, the cumulative distribution function F (Θ) of the scattering angle is expressed by the following equation (6).

  Here, I (Θ) in the equation (6) is the scattering intensity of the true spherical particle having the size parameter 表 represented by the equation (1). Assuming that light having an intensity Io is incident on the light-scattering light guide and transmitted through the distance y, the intensity of the light is attenuated to I due to scattering, and these relationships are expressed by the following equation (7).

  Τ in the equation (7) is called turbidity and corresponds to the scattering coefficient of the medium, and is proportional to the number N of particles as in the following equation (8). In the equation (8), σs is a scattering cross section.

  From the equation (7), the probability Pt (L) of transmitting the light scattering light guide having a length L without scattering is expressed by the following equation (9).

On the other hand, the probability Ps (L) scattered up to the optical path length L is expressed by the following equation (10).

  As can be seen from these equations, the degree of multiple scattering in the light scattering light guide can be controlled by changing the turbidity τ.

  By the above relational expression, it is possible to control multiple scattering in the light scattering light guide using at least one of the size parameter Α and turbidity τ of the scattering fine particles as a parameter, and the outgoing light intensity and scattering angle on the outgoing surface can also be controlled. It can be set appropriately.

  Here, the light scattering particles contained in the light guide 3 are translucent silicone particles having an average particle diameter of 2.4 μm. The turbidity τ, which is a scattering parameter corresponding to the scattering coefficient by the light scattering particles, is τ = 0.49 (λ = 550 nm).

  Illuminance distribution in the second embodiment is shown in FIGS. FIGS. 6A, 6B and 7A, 7B are illuminance distributions at the position of the diffusion cover C placed on the upper surface 31 of the light guide 3, as in FIGS. ((A) of each figure) and the result ((b) of each figure) measured from each direction along the spherical surface cut by the vertical vertical line of (a) of each figure are shown. 6 shows the case where the particle diameter of the light scattering fine particles is 2.0 μm and the concentration is 0.01 wt%, and FIG. 7 shows the case where the particle diameter of the light scattering fine particles is 2.0 μm and the concentration is 0.1 wt%.

  Comparing FIG. 4 which is the illuminance distribution diagram of the first embodiment with FIGS. 6 and 7 which are illuminance distribution diagrams of the second embodiment, the illuminance distribution diagram of the second embodiment is a gentler line. It can be seen that the difference in illuminance between the vicinity of the center and the surrounding area is also small. Therefore, by using the light-scattering light guide, it is possible to provide an illumination device with a wide light distribution and more uniform illuminance. 6 and FIG. 7, there is no significant difference in each figure (a), but when looking at each figure (b), FIG. 7 with a large amount of scattering material is compared with FIG. It shows that light is radiated more evenly in the side surface direction (see FIG. 2).

  In the second embodiment, volume scattering is generated by using the light guide 3 as a light-scattering light guide. However, even if the light guide 3 is only a transparent resin, it is an emission surface of the light guide. The side surface 32 may be roughened to generate surface scattering. FIG. 8 shows an illuminance distribution diagram of the illumination device of the third embodiment.

  1 and 2 is an example in the case where the shape of the light guide 3 is a columnar shape, but as a modification of the first to third embodiments, the illumination device A4 of the fourth embodiment is illustrated in FIG. Shown in The illuminating device A4 according to the fourth embodiment extends the cross-sectional shapes of the substrate 1 and the light guide 3 in FIG. 2 in a direction orthogonal to the paper surface, and arranges a plurality of LEDs 2 on the substrate, so that FIG. As shown in FIG. 4, a line-shaped illumination device A4 is provided. Such a line-shaped lighting device A4 is mounted on, for example, the left and right upper corners in the showcase to illuminate the displayed product downward from the left and right upper sides, and realizes an illumination mode that was not possible with a conventional lighting device. be able to.

  Next, an illuminating device A5 according to a fifth embodiment is shown in FIG. The lighting device A5 is a circle-shaped lighting device in which the cross-sectional shapes of the substrate 1 and the light guide 3 in FIG. In this case, the circular illumination device A5 includes a plurality of LEDs 6 mounted on the circumference of the substrate 5, and a cylindrical light guide 7 provided on the same side of the substrate 5 as the LEDs 6 with the LEDs 6 interposed therebetween. In addition, the light-guiding body 7 is constituted by a transmittance adjusting member 8 provided on the upper surface of the slope. The light guide 7 is made of a transparent resin in an annular shape, and an upper surface of the light guide 7 is provided with an inclined surface 71 that is inclined from the outside to the inside, and a transmittance adjusting member 8 is provided on the inclined surface. It is. A ring-shaped transmission part 81 is provided at the center of the transmittance adjusting member 8, and reflection parts 82 are provided above and below it. The LEDs 6 on the substrate 5 are preferably arranged on the circumference at equal intervals.

  You may use the light-scattering light guide of the said 2nd Embodiment also for the light guide 7 of illuminating device A5 of the said 5th Embodiment. In this case, the particle diameter is preferably 1 to 10 μm and the concentration is preferably 0.01 to 0.2 wt%.

[Sixth Embodiment]
As shown in FIGS. 11 to 13, the illuminating device A6 according to the sixth embodiment includes LEDs 6 on the circumference of two concentric circles inside and outside the substrate 5 similar to the substrate 5 of the circle-shaped illuminating device A5 in FIG. 10. Preferably, they are arranged at equal intervals. For example, six LEDs 6 are arranged on the inner side and ten LEDs 6 are arranged on the outer side. On the same side of the substrate 5 as the LED 6 is disposed, the light guide 7 provided with the LED 6 in between is formed in an annular shape, and the inner and outer double LEDs 6 (where the inner peripheral LED is the LED 6a, the outer peripheral LED The LED has two annular light guide portions 7a and 7b respectively corresponding to the LED 6b. A transmittance adjusting member 8 is provided on the upper slope of the light guide 7 in FIG. A part of the transmittance adjusting member 8 is a groove 7c serving as a transmitting portion. This transmitting portion has a width narrower than the distance between the inner and outer double LEDs 6a and 6b, and is a groove 7c that opens continuously in the circumferential direction. The bottom surface of the groove 7c is a horizontal plane. The transmittance adjusting member 8 of the sixth embodiment corresponds to the transmittance adjusting member 4 in the first to fourth embodiments, and the groove 7c corresponds to the transmitting portion 41 in the first to fourth embodiments.

  The light guide portions 7a and 7b of the light guide 7 transmit the light from the LEDs 6a and 6b and guide the light to the transmittance adjusting member 8, and emit the light reflected by the transmittance adjusting member 8 from the side surface. In 6th Embodiment, the height (bH) of the light guide part arrange | positioned outside is larger than the height (aH) of the light guide part arrange | positioned inside (aH <bH). The traveling direction of the light beam in the sixth embodiment is shown in FIG. FIG. 14 corresponds to FIG. 3 of the first embodiment. In FIG. 14, only the traveling direction of the light beam on the right side of each figure is shown, and the light beam on the left side is omitted.

  As shown in FIGS. 13 and 14, when the height of the outer light guide 7b is larger than the height of the inner light guide 7a, the direction from the side surface of the inner light guide 7a to the outer light guide 7b is increased. Since the light emitted to the outer light guide part 7b is incident on and transmitted through the outer light guide part 7b, it can be emitted laterally (horizontal direction, diagonally upward direction or diagonally downward direction) from the side surface of the outer light guide part 7b. A lighting device having a large lateral irradiation rate can be obtained. On the other hand, when the height of the outer light guide 7b is made smaller than the height of the inner light guide 7a, the light emitted from the side surface of the inner light guide 7a in the direction of the outer light guide 7b. Is reflected upward by the transmittance adjusting member 8 of the outer light guide 7b. As a result, the ratio that contributes to illuminating the horizontal direction is small.

  Illuminance distribution in the case where the light guide body 7 of the illumination device A6 according to the sixth embodiment is a transparent material, and an example of a case in which the light guide body 7 in the sixth embodiment is a light scattering light guide body that generates volume scattering. Illuminance distribution, illuminance distribution of another example when the light guide 7 of the sixth embodiment is a light scattering light guide that generates volume scattering, the surface where the light guide 7 of the sixth embodiment generates surface scattering Illuminance distributions in the case of a scattering light guide are shown in FIGS. 15, 16, 17, and 18, respectively. Each of FIGS. 15 to 18 is centered on the origin m (the center in the xz direction of the illumination device A6) in FIG. 13, and the upper left diagram in FIG. In the illuminance distribution above (not shown), the vertical line is a z-direction line passing through the origin m, and the horizontal line is an x-direction line passing through the origin m. The lower graph of (a) in each figure is an illuminance graph measured along a horizontal line, and the right graph is an illuminance graph measured along a vertical line. Moreover, the graph of (b) of each figure is a graph showing the intensity | strength of the illumination intensity seen from each direction along a yz plane. That is, FIGS. 15, 16, 17, and 18 are views expressed in the same way as FIG.

  As can be seen from these figures, in terms of illuminance, the center of the light guide 7 is not so large, and is the largest at a position slightly shifted to the outer peripheral side from directly above the LED 6b. Moreover, as a matter of course, it is point-symmetric about the origin m. Also, as shown in (b) of each figure, the intensity seen from each figure on the yz plane is that the light is the strongest in the vicinity of +80 degrees and -80 degrees, and the illuminance in the lateral direction is high. It has become. Further, much light is directed not only to the front side region B1 but also to the back side region B2. By attaching the diffusion cover to the illumination device A6 according to the sixth embodiment, light with more uniform illuminance can be emitted from the top surface, side surface, and back surface of the diffusion cover.

  FIG. 19 shows an illuminating device A7 according to a seventh embodiment which is another modification of the sixth embodiment. In FIG. 19, the advancing direction of the light which injects into light guide from LED6a, 6b in the case of illuminating device A7 is shown. (a) is a diagram showing a traveling direction of light incident on the light guide in a substantially vertical upward direction, (b) is a diagram showing a traveling direction of light incident on the light guide in an oblique right direction, and (c) is a guide. It is a figure which shows the advancing direction of the light which injects into a light body in the diagonally left direction. FIG. 19 corresponds to FIG. 14 of the sixth embodiment. In FIG. 19, only the traveling direction of the light beam on the right side of each figure is shown, and the light beam on the left side is omitted. In this modification, the light guide 9 is reflected by the transmittance adjusting member 10 and emitted in the lateral direction by reducing the difference in height between the light guide portion 9a on the outer peripheral side and the light guide portion 9b on the inner peripheral side. The reflected light beam is reflected again by the transmittance adjusting member 10 and is emitted as an upward light beam. As a result, the amount of light in the upward direction can be increased. Thus, by changing the difference in height between the light guide portion 9a and the light guide portion 9b, the illumination direction can be set to a direction and illuminance suitable for the purpose, such as a horizontal direction or an upward direction.

  20 and 21 are views showing a modification of the illumination device A6 of the sixth embodiment, and show the illumination device A8 according to the eighth embodiment. The difference between the illumination device A8 and the illumination device A6 is the following three points. The first point is that the lighting device A8 is provided with a plurality of connecting portions 7d that connect the light guide portions 7a and 7b. Second, the illumination device A8 is provided with a bottom 7e at the center of the light guide 7. Third, in the illumination device A6, the LEDs 6a and 6b are mounted in the recesses of the substrate 5, and the light emitting surface is the same as the surface of the substrate 5, whereas in the illumination device A8, the LEDs 6a and 6b are formed on the surface of the substrate 5. Is attached, and the reference surface B serving as the light emitting surface is slightly closer to the light guide 7 than the surface of the substrate 5. This illuminating device A8 also emits more light in the lateral direction or the backward direction, so that it is possible to widen the light distribution and reduce the thickness.

  Next, an illuminating device A9 according to a ninth embodiment of the present invention is shown in FIG. This illuminating device A9 is a triple illuminating device A6, and if the upper surface of the light guide 7 has no groove 7c, it has a fixed angle, preferably an inclination angle of 45 degrees. It is one continuous slope. Two ring-shaped grooves 7c1 and 7c2 are provided in the slope. A plurality of S1 LEDs are arranged at equal intervals on the outermost periphery, a plurality of S2 at equal intervals on the middle periphery, and S3 at equal intervals on the innermost periphery. At this time, the number of LEDs is preferably “S1> S2> S3”, but may be another relationship such as “S2> (S1 = S3)”. Further, as a modification of the lighting device A9, a connecting portion 7d or a bottom portion 7e may be provided as in the lighting device A8.

  Next, FIG. 23 shows an illuminating device A10 according to the tenth embodiment of the present invention. The illumination device A10 is configured by arranging a plurality of illumination devices A11 and A12 substantially the same as the illumination device A1 with a circular interval. Both the illuminating devices A11 and A12 have an inner peripheral surface and an outer peripheral surface formed in an arc shape, and are configured to be a part of a circle (= arc) centered on the origin m. The illuminating device A11 disposed on the outer peripheral side is larger in height and width than the illuminating device A12 disposed on the inner peripheral side. One illumination device A11 arranged on the outer peripheral side is arranged for each LED, and the interval between the adjacent illumination devices A11 is non-uniform, but may be equal. Similarly, each of the illumination devices A12 arranged on the inner peripheral side is arranged for one LED, and the intervals are not uniform, but may be equally spaced. Moreover, you may arrange | position one illuminating device A11 and one illuminating device A12 with respect to several LED, and may mix one and several things. Moreover, although the illuminating device A10 is made into double arrangement | positioning inside and outside, you may make it triple arrangement | positioning or make it only single.

[Other embodiments]
The lighting device according to each embodiment of the present invention has been described above, but the present invention is not limited to the above-described configuration, and various modifications can be made without departing from the object of the present invention. For example, although the transmittance adjusting members 4 and 8 have been described as examples in which a part is configured as a transmission part and the other part is configured as a reflection part, the difference between the transmission part and the reflection part is a difference in light transmittance. The light transmittance may be set as appropriate according to the amount of light desired to be emitted from the upper surface of the light guide. That is, the transmittance adjustment member having a constant transmittance may be disposed on the entire slope such as the upper surface 31 without providing the transmission portion 41 and the groove 7c, or may be disposed so that the transmittance is partially different. Moreover, even if it is a reflection part, when it is thin, it may transmit a part without reflecting all the light. Even in the transmissive portion, light may be reflected depending on the incident angle of light with respect to the inclined surface of the light guide.

  That is, the transmittance adjusting member is partially divided into a transmitting portion and a reflecting portion, or by adjusting the transmittance of light emitted to the entire surface without being divided, from the inclined surface (upper surface) of the light guide. The amount of light emitted can be appropriately suppressed, and the amount of light emitted from the side surface and the amount of light emitted to the back can be appropriately increased. Thereby, the attachment surface of an illuminating device can be illuminated with arbitrary illumination intensity. Therefore, when performing indirect illumination using a conventional illumination device, it is necessary to attach a reflector or the like. However, each illumination device according to the present invention does not require the addition of such a reflector. Is possible.

  In addition, in the illumination devices A6, A7, A8, and A9, the groove 7c is provided, but instead of the groove 7c, the light guide portions 7a and 7b may be formed as through holes, and both may be completely separated. Similarly, it is good also as a through-hole between the light guide parts 7a and 7b or between the two in the case of triple. In addition, in each lighting device, there is emitted light directed to the back side region B2, which is the opposite side of the light emitting surface of the light source, but the light directed to the back side region B2 is eliminated, and the front direction, the oblique front direction, the lateral direction, etc. You may make it become only the light which goes to the front side area | region B1, so that it may become only the emitted light which goes. In each lighting device, a light guide is used. However, the light source may not be used and light from the light source may be directly applied to the transmittance adjusting member.

  Each lighting device is used by covering the whole with a diffusion cover C such as a globe. Since the light emitted from the side surface of the light guide has a small difference in brightness, the diffusion cover C can be attached close to the light guide, and the lighting device can be downsized. However, the diffusion cover may not be used or another cover may be used. The light source is preferably an LED, but other light sources such as an incandescent bulb, a fluorescent lamp, and EL (Electro luminescence) may be used.

1 Substrate 2 LED (light source)
3 Light Guide 31 Upper Surfaces 32 and 33 of Light Guide Side 4 of Light Guide 4 Transmittance Adjusting Member 41 Transmitter 42 Reflector 5 Substrate 6, 6a, 6b Light Source (LED)
7 Light guide 7a, 7b Light guide 7c Groove (transmission part)
8 Transmittance adjusting members A1 to A10 Illuminating device B1 Front side region B2 Back side region C Diffusion cover

Claims (5)

In an illuminating device, comprising: a light source installed on a substrate; and a light guide that is arranged on the same side of the substrate as the light source and sandwiches the light source, and introduces and transmits light from the light source. ,
A side of the light guide opposite to the light source has a slope shape, and a transmittance adjusting member that transmits a part of the light passing through the light guide and reflects most of the light is along the slope shape. And place
The transmittance adjusting member has a high transmittance portion formed by opening a hole in a part thereof, and a low transmittance portion is formed by a portion other than the hole.
A lighting device characterized by that. A lighting device according to claim 1 Symbol mounting, the light guide is molded by dispersing light scattering particles in a transparent resin material, the lighting device, characterized in that the light scattering guide for generating volume backscattering. 3. The illumination device according to claim 1, wherein the light guide is a surface-scattering light-guide that is formed of a transparent resin material and has an emission surface that generates surface scattering by roughening or the like. apparatus. A lighting device according to any one of claims 1 to 3, wherein the light guide is columnar, lighting apparatus, characterized in that linear, is either circle-shaped. A lighting device as claimed in any one of 4, the light source is a plurality spaced respectively intervals on a plurality of circumferences having a common center, the lightguide that each circle A light guide portion formed in an annular shape along the circumference, and the slope of each light guide portion is inclined upward from the inside to the outside, and the transmittance adjusting member is disposed on the slope, and the inside The height of the light guide unit arranged outside the height of the light guide unit arranged at the top is increased, and a groove or a through-hole opening upward is formed between the annular light guide units, and the transmission An illumination device characterized by being a high transmittance part of the rate adjusting member.