JP2018010814A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device capable of suppressing volatile lines reflected on an object such as a wall surface or a floor surface. An illuminating device 1 includes a light source 41 and a light guide plate 6 having an incident surface 61 on which the light of the light source 41 is incident. The light guide plate 6 is formed on a first emitting surface 63 intersecting the incident surface 61, a second emitting surface 64 on the opposite side of the first emitting surface 63, and on the opposite side of the incident surface 61 to emit light. It has a convex structure 62. A large number of microprism elements 67 are formed on at least one of the first exit surface 63 and the second exit surface 64. The convex structure 62 has an emission end face 65 that controls light distribution. [Selection diagram] Fig. 3

Description

  The present invention relates to an illumination device using a light guide plate that emits guided light.

  2. Description of the Related Art Conventionally, a flat illumination device (an example of an illumination device) including a light source and a light guide plate having an incident portion (an example of an incident surface) that guides light from the light source has been disclosed (see, for example, Patent Document 1). The light guide plate has a first emission surface portion (an example of a first emission surface) and a second emission surface portion (an example of a second emission surface), and emits light from the first emission surface portion and the second emission surface portion.

  In this flat illumination device, uniform light is emitted from the first emission surface portion and the second emission surface portion.

JP 2004-111353 A

  However, in the conventional illuminating device, the light emitted from the emission end surface on the opposite side to the incident surface causes volatiles to occur on an object such as a wall surface or a floor surface.

  Then, an object of this invention is to provide the illuminating device which can suppress the volatility reflected in objects, such as a wall surface and a floor surface.

  In order to achieve the above object, an illumination device according to an aspect of the present invention is an illumination device including a light source and a light guide plate having an incident surface on which light of the light source is incident. A first exit surface intersecting the entrance surface, a second exit surface opposite to the first exit surface, and a convex surface or a concave surface formed on the opposite side of the entrance surface and emitting light. A plurality of prisms are formed on at least one of the first emission surface and the second emission surface, and the concave surface or the convex surface controls light distribution.

  According to the present invention, it is possible to suppress volatility reflected on an object such as a wall surface or a floor surface.

It is a perspective view which shows the illuminating device which concerns on embodiment. It is a partial expanded sectional view which shows the illuminating device which concerns on embodiment in the AA of FIG. It is a partial expanded sectional view which shows the convex-shaped structure of the light-guide plate in the illuminating device which concerns on embodiment in the AA of FIG. It is an image figure which shows the light distribution of the light-guide plate in the illuminating device which concerns on embodiment. FIG. 5A is an image diagram showing light distribution emitted from the first emission surface and the second emission surface of the light guide plate in the illumination device according to the embodiment. FIG. 5B is an image diagram showing light distribution of light emitted from the emission end face of the light guide plate in the illumination device according to the embodiment. FIG. 5C is an image diagram showing the light distribution of the light emitted from the emission end face of the light guide plate in the illumination device according to the embodiment. (D) of FIG. 5 is the figure which showed the relationship between the divergence angle of a light distribution, and a focal distance in the illuminating device which concerns on embodiment. It is a partial expanded sectional view which shows the convex-shaped structure of the light-guide plate in the illuminating device which concerns on embodiment. It is an image figure which shows the light distribution of the light-guide plate in the illuminating device which concerns on the modification 1 of embodiment. FIG. 8A is a partially enlarged perspective view showing the convex structure of the light guide plate in the lighting device according to Modification 2 of the embodiment. FIG. 8B is a partially enlarged cross-sectional view showing the convex structure of the light guide plate in the illumination device according to Modification 2 of the embodiment along the line BB in FIG. It is a partial expanded sectional view which shows the concave structure of the light-guide plate in the illuminating device which concerns on the modification 3 of embodiment. It is an image figure which shows the light distribution of the light-guide plate in the illuminating device which concerns on a comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  In addition, the description of “substantially **” is intended to include not only exactly the same, but also those that are recognized as being substantially the same, with “substantially identical” as an example.

  Each figure is a schematic diagram and is not necessarily illustrated strictly. Moreover, in each figure, the same code | symbol is attached | subjected to the substantially same structure, The overlapping description is abbreviate | omitted or simplified.

  Hereinafter, a lighting device according to an embodiment of the present invention will be described.

(Embodiment)
[Constitution]
First, the structure of the illuminating device 1 which concerns on this Embodiment is demonstrated using FIGS. 1-3.

  FIG. 1 is a perspective view showing a lighting device 1 according to the present embodiment. FIG. 2 is a partially enlarged cross-sectional view showing lighting apparatus 1 according to the present embodiment taken along line AA in FIG. FIG. 3 is a partial enlarged cross-sectional view showing the convex structure 62 of the light guide plate 6 in the lighting device 1 according to the present embodiment taken along the line AA in FIG.

  In FIG. 1, in the illumination device 1, the first emission surface 63 side of the illumination device 1 is defined as the front direction, the opposite second emission surface 64 side is defined as the rear direction, and the incidence surface 61 side of the illumination device 1 is defined as the upward direction. The direction, the output end face 65 side opposite to the direction, is defined as the downward direction, and the front-rear, left-right, and up-down directions are displayed. 2 are displayed in correspondence with the directions shown in FIG. 1. In addition, in FIG. 1, since an up-down direction, a left-right direction, and the front-back direction change with usage modes, it is not limited to this. The same applies to the subsequent drawings.

  As shown in FIG. 1, the lighting device 1 uses an edge light system, and is disposed, for example, embedded in a wall or ceiling in a facility. In this Embodiment, the illuminating device 1 is arrange | positioned in the ceiling in the state which made the light-guide plate 6 protrude from the ceiling.

  As shown in FIG. 2, the lighting device 1 includes a housing 3, a light emitting module 4, a pair of reflecting plates 5, a light guide plate 6, a heat radiating unit 8, and a power supply unit 9.

  The casing 3 is a bottomed box that is long in the left-right direction and has an opening formed below the casing 3. The housing 3 houses a plurality of light sources 41, a pair of reflecting plates 5, a light guide plate 6, a heat radiating unit 8, and a power source unit 9. The housing 3 is fixed to the ceiling by fixing means (not shown) so as not to fall from the ceiling. The fixing means may be fixed with a bolt or the like that passes through a screw hole (not shown) provided in the housing 3 or may be fixed with an adhesive or the like as long as it can be fixed to the ceiling. Any means may be used.

  The light emitting module 4 is a module having a plurality of light sources 41 and a wiring board 42 on which the plurality of light sources 41 are arranged. The light emitting module 4 is provided above the light guide plate 6 and has a plate shape elongated in the left-right direction. In the present embodiment, the light emitting module 4 is fixed to the housing 3 so as to be in a substantially horizontal state.

  Each light source 41 is electrically connected to the wiring board 42. The wiring board 42 is electrically connected to the power supply unit 9. The light source 41 is separated from the light guide plate 6 so as not to come into contact with the light guide plate 6, and is disposed so that light enters the incident surface 61 of the light guide plate 6. In other words, the light source 41 is mounted on the wiring board 42 so that the light emitting direction is opposite to the incident surface 61 of the light guide plate 6, and emits light toward the incident surface 61 of the light guide plate 6. The optical axis X of each light source 41 is disposed so as to be substantially parallel to the light guide plate 6 and substantially orthogonal to the incident surface 61 of the light guide plate 6. In the present embodiment, the optical axis X of the light source 41 is directed downward.

  The light source 41 is a so-called SMD (Surface Mount Device) type LED element. Specifically, the SMD type LED element is a package type LED element in which an LED chip (light emitting element) is mounted in a resin-molded cavity, and a phosphor-containing resin is sealed in the cavity. The light source 41 is turned on and off under the control of a control circuit (not shown) provided in the power supply unit 9. In addition, each light source 41 is controlled by a control circuit provided in the power supply unit 9 to perform dimming and toning.

  The light source 41 is not limited to such a configuration, and a COB (Chip On Board) type light emitting module 4 in which an LED chip is directly mounted on a substrate (not shown) of the light source 41 is used. Also good. The light emitting element included in the light source 41 is not limited to the LED. For example, a semiconductor light emitting element such as a semiconductor laser, or another solid light emitting element such as an EL element such as an organic EL (Electro Luminescence) or an inorganic EL. It may be.

  The pair of reflecting plates 5 is a member that is long in the left-right direction and capable of controlling the light distribution from the first emitting surface 63 and the second emitting surface 64 of the light guide plate 6 in the downward direction. The reflection plate 5 may be formed of, for example, a metal material such as aluminum, and a white diffuse reflective coating or a metal vapor deposition film (metal reflection film) made of a metal material such as silver or aluminum is formed. Realized by mirror finish by mirror coating or polishing.

  One (front side) reflector 5 is disposed on the front upper side of the light guide plate 6, and the other (rear) reflector 5 is disposed on the rear upper side of the light guide plate 6. One (front) reflector 5 is disposed symmetrically with the other (rear) reflector 5, and the pair of reflectors 5 sandwich the light guide plate 6.

  The front reflector 5 has a sandwiching part 51, an umbrella part 52, an abutting part 53, an extending part 54, and a plurality of support parts 55. In FIG. 2, a description will be given in the case where the reflecting plate 5 is viewed in cross section along a plane defined in the vertical direction and the front-rear direction.

  The sandwiching portion 51 has a flat plate shape that is long in the left-right direction, and is in contact with the upper side of the light guide plate 6 in a state of being upright in the up-down direction. A plurality of through holes through which screws are inserted are formed in the clamping part 51. The umbrella portion 52 has a flat plate shape that is long in the left-right direction, and is curved with respect to the sandwiching portion 51 so as to incline downward from the lower end edge of the sandwiching portion 51 toward the front side. The contact portion 53 has a flat plate shape that is long in the left-right direction, and extends upward from the lower end edge of the umbrella portion 52 in an upright state. The contact portion 53 is in contact with the inner surface of the housing 3 in a state where the reflecting plate 5 is accommodated in the housing 3. The extending portion 54 has a flat plate shape that is long in the left-right direction, and is bent at a substantially right angle from the upper end edge of the sandwiching portion 51 toward the front. Each of the support portions 55 protrudes upward from the front end edge of the extending portion 54. Each support portion 55 has a plurality of through holes through which bolts are inserted. Each support part 55 may fix the heat radiating part 8 with a bolt (not shown).

  The rear reflector 5 is provided symmetrically with respect to the front reflector 5 with respect to the surfaces defined in the vertical and horizontal directions, and has the same configuration as the front reflector 5, and has the same reference numerals. The explanation is omitted.

  The light guide plate 6 has a flat plate shape that is long in the left-right direction, and is sandwiched between the pair of reflection plates 5 in an upright direction. The light guide plate 6 has a rectangular flat plate shape when viewed from the front. In addition, the shape of the light guide plate 6 is not limited to a rectangular shape, and may be a disc shape or other shapes such as a triangular shape. The light guide plate 6 is supported substantially perpendicularly to the ceiling, but may be supported horizontally or may be supported diagonally. Moreover, not only a ceiling but a wall, a floor, etc. may be provided.

  When the light guide plate 6 is viewed from the first exit surface 63 or the second exit surface 64, the front-rear direction of the light guide plate 6 is the thickness of the light guide plate 6, and the left-right direction of the light guide plate 6 is the longitudinal direction. The vertical direction of the light guide plate 6 is the short direction of the light guide plate 6.

  The light guide plate 6 is an optical member that transmits light from the light source 41. The light guide plate 6 is a light-transmitting resin such as glass, polycarbonate, or acrylic, but may be formed of any other material.

  As shown in FIG. 3, the light guide plate 6 has an incident surface 61, a convex structure 62, a first output surface 63, a second output surface 64, and an output end surface 65 (an example of a convex surface). .

  The incident surface 61 is the upper end surface of the light guide plate 6, and the light emitted from each light source 41 is incident thereon. The incident surface 61 is a flat surface that is long in the left-right direction substantially orthogonal to the optical axis X of the light source 41. The first emission surface 63 is a front plane of the light guide plate 6, and light guided through the light guide plate 6 is emitted. The second emission surface 64 is a rear flat surface of the light guide plate 6 that is opposite to the first emission surface 63, and light guided through the light guide plate 6 is emitted.

  The convex structure 62 in the case where the light guide plate 6 is viewed in cross section along a plane defined in the vertical direction and the front-rear direction will be described.

  The convex structure 62 is a convex portion protruding downward and formed on the lower end side of the light guide plate 6. The convex structure 62 has an isosceles triangular shape and projects downward. The lower end surface of the convex structure 62 is an emission end surface 65 that emits light. The convex structure 62 has a lens function for diverging or converging light from the emission end face 65. The emission end face 65 is a flat and uniform surface, but the emission end face 65 may be formed with a diffusion structure for diffusing light. For example, the diffusion structure may be fine uneven sandblast. The exit end face 65 is the end face opposite to the entrance face 61 (the lower end face of the light guide plate 6), and the guided light exits. The emission end face 65 has a front emission end face 65a and a rear emission end face 65b.

  The front emission end face 65a is inclined downward from the lower end edge (an example of an end edge) of the first emission face 63 toward the rear side. The front emission end face 65a is a long face in the left-right direction. The rear emission end face 65b is inclined up to the lower end face of the second emission face 64 from the lower end edge of the front emission end face 65a toward the rear side. The rear emission end face 65b is a long face in the left-right direction. The front-side outgoing end face 65a and the rear-side outgoing end face 65b are symmetric with respect to a plane defined by the up-down direction and the left-right direction.

  The following relationship is satisfied for the convex structure 62. The thick solid line shown in FIG. 3 indicates the guided light.

  The focal length of the convex structure 62 is denoted by F. The focal length F is the distance from the point where the thick solid lines intersect to the virtual straight line K. The distance from the convex structure 62 to the irradiation surface of the object is represented by L. That is, the distance from the virtual straight line K to the irradiation surface of the object is represented by L. Here, the target object is a target object irradiated with light from the light guide plate 6, such as a wall or a floor.

  Further, a part of a straight line where the first emission surface 63 and the front emission end surface 65a intersect is defined as a first point P1. In addition, a part of a straight line intersecting the second emission surface 64 and the rear emission end surface 65b is defined as a second point P2. A straight line connected by the first point P1 and the second point P2 is defined as a virtual straight line K. The height from the virtual straight line K to the apex of the convex structure 62 (a straight line where the front emission end face 65a and the rear emission end face 65b intersect) is assumed to be h. In other words, the height h is the distance from the virtual straight line K to the apex of the convex structure 62. The thickness from the first emission surface 63 to the second emission surface 64 is represented by d. Further, the refractive index of the light guide plate 6 is represented by n. In this case, the conditions of Formula 1 and Formula 2 are satisfied.

  Formula 2 is calculated from Formula 3 of the focal length of the lens, Formula 4 of the sine theorem, and Formula 5 of the double angle formula.

In Equations 3 to 5, R ₁ is the radius of curvature of the circle indicated by the two-dot chain line in FIG. 3, θ is the angle defined by the virtual straight line K and the front emission end face 65a, and the virtual straight line K and the rear emission. The angle is defined by the end face 65b. In the present embodiment, R ₂ is ∞ because it does not exist. In the present embodiment, the convex structure 62 is a substantially isosceles triangle, but it is calculated by approximating it as an arc. In the light guide plate 6 in the present embodiment, the thickness d is 4 mm, the angle θ is 3 °, the height h is 0.1 mm, the refractive index n is 1.49, and R ₁ is 19 mm. is there. In this case, the focal length F can be derived as 39 mm from Equations 1 to 5.

  A plurality of groove-shaped microprism elements 67 (an example of a prism) that are recessed from the first emission surface 63 toward the second emission surface 64 are formed on the first emission surface 63. A plurality of groove-shaped microprism elements 67 that are recessed from the second emission surface 64 toward the first emission surface 63 are also formed on the second emission surface 64. A plurality of microprism elements 67 are formed on the first emission surface 63 and the second emission surface 64 according to a certain rule. The microprism element 67 is a conical recess. The inner peripheral surface of the microprism element 67 is a triangular pyramid-shaped curved surface (tapered surface).

  A plurality of through holes penetrating in the front-rear direction are formed on the upper end side of the light guide plate 6. Each of the through holes has a one-to-one correspondence with each of the through holes formed in the sandwiching portion 51 of the pair of reflecting plates 5. The pair of reflection plates 5 and the light guide plate 6 are fixed by bolts and nuts inserted in the order of the front holding portion 51, the through hole of the light guide plate 6, and the rear holding portion 51. The method for fixing the light guide plate 6 is not limited to bolts and nuts, and a known method may be adopted as long as the light guide plate 6 can be fixed.

  The heat dissipating unit 8 is in surface contact with the upper surface of the wiring board 42 so that heat generated by the light source 41 is conducted through the wiring board 42 to be dissipated. The heat dissipating part 8 is a metal member (metal strut part), and in order to efficiently dissipate the heat generated in the light emitting module 4 to the housing 3, aluminum (Al), copper (Cu), iron (Fe), or the like is used. You may comprise as a main component the metal material with high heat conductivity. Moreover, you may comprise the thermal radiation part 8 using not only metal but the resin material with high heat conductivity.

  The power supply unit 9 is configured by a power supply circuit that generates power for causing the light emitting module 4 to emit light. The power supply unit 9 converts, for example, power supplied from the power system into direct current power of a predetermined level by rectification, smoothing, stepping down, and the like, and supplies the direct current power to the light emitting module 4. The power supply unit 9 is electrically connected to the power system through a power line such as a control line.

  For example, the power supply unit 9 is controlled by a control circuit of the power supply unit 9 to turn on and off the power supply to the light emitting module 4. For example, when a lighting operation is received through an operation unit such as a remote controller, the control circuit supplies power from the power supply unit 9 to the light emitting module 4 to turn on the light source 41 of the light emitting module 4. When the operation unit receives an operation for turning off the light, the control circuit turns off the light source 41 of the light emitting module 4 by cutting off the supply of power from the power supply unit 9 to the light emitting module 4.

  The behavior of light emitted from the light source 41 in the illumination device 1 will be described with reference to FIG.

  FIG. 4 is an image diagram showing the light distribution of the light guide plate 6 in the illumination device 1 according to the present embodiment.

  As shown in FIG. 4, the light emitted from the light source 41 enters from the incident surface 61 of the light guide plate 6 and guides the inside. For example, light incident on the microprism element 67 is scattered by the microprism element 67. The light scattered by the microprism element 67 is emitted from the first emission surface 63 and the second emission surface 64, or reflected by the first emission surface 63 and the second emission surface 64. Further, for example, when light that guides the inside enters the emission end face 65, a part of the light is emitted from the emission end face 65, or a part of the light is reflected by the emission end face 65. In such an illuminating device 1, it becomes a light distribution characteristic as shown by the dashed-two dotted line of FIG.

  FIG. 5A is an image diagram showing the light distribution emitted from the first emission surface 63 and the second emission surface 64 of the light guide plate 6 in the illumination device 1 according to the present embodiment. FIGS. 5B and 5C are image diagrams showing the light distribution of the light emitted from the emission end face 65 of the light guide plate 6 in the illumination device 1 according to the present embodiment. FIG. 5D is a diagram showing the relationship between the light distribution spread angle and the focal length F in the illumination device 1 according to the present embodiment.

  In FIG. 5A, for example, light that satisfies the condition of total reflection out of light incident on the microprism element 67 on the first emission surface 63 is emitted from the second emission surface 64 on the opposite side. Light that does not satisfy the condition of total reflection is emitted from the microprism element 67 on the first emission surface 63.

  FIG. 5B shows light emitted from the emission end face 65 among the light scattered by the first emission surface 63, the second emission surface 64, and the like. For example, a part of the light incident on the microprism element 67 on the first exit surface 63 is scattered and enters the exit end surface 65. Then, the light is emitted from the emission end face 65.

  FIG. 5C shows the light emitted from the light emitting end surface 65 when the light from the light source reaches the light emitting end surface 65 directly.

  When (A) in FIG. 5 to (C) in FIG. 5 are overlapped, light distribution characteristics as shown by the two-dot chain line in FIG. 4 are obtained.

  When the illumination device 1 according to the embodiment is used, the relationship between the light spread angle and the focal length F as shown in FIG. Here, the spread angle of the light distribution shown in FIG. 5B is the light emitted from the emission end face 65 out of the light scattered by the first emission surface 63 and the second emission surface 64, etc. The 1/2 beam angle in the light distribution by is shown.

  As indicated by the alternate long and short dash line in FIG. 5D, when the focal length F is less than 20 mm (spreading angle 25 °), the spreading angle of the light distribution increases. In this case, the light distribution characteristic as shown in FIG. 4 cannot be obtained. Therefore, by setting the focal length F to 20 mm or more, the spread angle of the light distribution does not spread too much, and the volatile lines reflected on the object such as the wall surface or the floor surface can be suppressed.

  FIG. 6 is a partial enlarged cross-sectional view showing the convex structure 62 of the light guide plate 6 in the illumination device 1 according to the present embodiment. As shown in FIG. 6, the convex structure 62 on the emission end face 65 of the light guide plate 6 may be arcuate. The arc may be a part of a perfect circle passing through the first point P1, the second point P2, and the vertex of the convex structure 62 in FIG. The arcuate surface 65e in FIG. 6 is the same as a part of the perfect circle of the two-dot chain line in FIG. Also in this case, the same characteristics as the light distribution characteristics shown in FIG. 4 are obtained.

[Comparative example]
A light guide plate in a lighting device according to a comparative example will be described with reference to FIG.

  FIG. 10 is an image diagram showing light distribution of the light guide plate 6 in the illumination device according to the comparative example. About the structure same as a comparative example about embodiment, the same code | symbol is attached | subjected and the detailed description regarding a structure is abbreviate | omitted.

  In the embodiment, the convex structure 62 exists on the lower end side of the light guide plate 6, but as shown in FIG. 10, in the comparative example, the convex structure 62 as in the embodiment does not exist, and the light guide plate 6 is different in that the lower end side of 6 is a flat surface substantially parallel to the incident surface 61. In such an illuminating device, the light distribution characteristic is as shown by a two-dot chain line in FIG. The light distribution characteristic of FIG. 10 shows a strong light distribution toward the lower side than the light distribution characteristic shown in FIG. In this illuminating device, the volatiles are reflected on the object by the light emitted from the lower end surface.

[Effects of Embodiment]
Next, the effect of the illuminating device 1 in this Embodiment is demonstrated.

  As described above, the illumination device 1 according to the present embodiment includes the light source 41 and the light guide plate 6 having the incident surface 61 on which the light of the light source 41 is incident. The light guide plate 6 is formed on the first emission surface 63 that intersects with the incidence surface 61, the second emission surface 64 opposite to the first emission surface 63, and the opposite side to the incidence surface 61, and emits light. And a convex structure 62. A large number of microprism elements 67 are formed on at least one of the first emission surface 63 and the second emission surface 64. The convex structure 62 has an emission end face 65 that controls light distribution.

  According to this configuration, the light guided through the light guide plate 6 toward the optical axis X direction (downward) is refracted by the emission end face 65 of the convex structure 62 and intersects the optical axis X direction (front-rear direction). ). For this reason, compared with the light guide plate 6 of FIG. 10 in which the convex structure 62 does not exist, the light distribution on the first light exit surface 63 and the second light exit surface 64 is hardly affected, and from the light output end surface 65 of the light guide plate 6. Light emitted in the direction of the optical axis X is weakened.

  Therefore, it is possible to suppress volatility reflected on an object such as a wall surface or a floor surface.

  Moreover, in the illuminating device 1 which concerns on this Embodiment, the light-guide plate 6 has the convex structure 62 in which the output end surface 65 was formed. The convex structure 62 has a lens function for diverging or converging light.

  According to this configuration, only by providing the light guide plate 6 with the convex structure 62 having a lens function, it is possible to suppress volatilization reflected on the object.

  In the illumination device 1 according to the present embodiment, the convex structure 62 extends along the lower end edge of the first exit surface 63 and the lower end edge of the second exit surface 64.

  According to this structure, since the cross section when the light guide plate 6 is cut in a plane defined by the vertical direction and the front and rear direction is substantially the same in any cross section, the light guide plate 6 is easy to manufacture. For this reason, an increase in the manufacturing cost of the light guide plate 6 can be prevented. For example, the light guide plate 6 can be manufactured by simple extrusion molding.

  Moreover, in the illuminating device 1 which concerns on this Embodiment, the light-guide plate 6 has the convex structure 62 in which the output end surface 65 was formed. When the convex structure 62 is cut in a plane perpendicular to the first emission surface 63 and the incident surface 61, the convex structure 62 represents the focal length of the convex structure 62 as F, and is convex. The distance from the structure 62 to the irradiation surface of the object is represented by L, the thickness from the first light emitting surface 63 to the second light emitting surface 64 is represented by d, and the line where the first light emitting surface 63 and the convex structure 62 intersect is indicated. The height of the convex structure 62 from the virtual straight line K connected by the first point P1 which is a part and the second point P2 which is a part of the line where the second emission surface 64 and the convex structure 62 intersect. When represented by h and the refractive index of the light guide plate 6 is represented by n, the conditions of Expression 6 and Expression 7 are satisfied.

  According to this configuration, it is difficult for volatiles to be reflected on an object such as a wall surface or a floor surface.

  In particular, the light distribution control of the emission end face 65 can be performed without affecting the light distribution of the entire lighting device 1. Further, even when the user views the emission end face 65 from the side (for example, from the front and back), glare emitted from the emission end face 65 can be reduced. For this reason, it is hard to give a user discomfort.

  Further, in the lighting device 1 according to the present embodiment, the convex structure 62 when cut along a plane orthogonal to the first exit surface 63 and the entrance surface 61 has a substantially isosceles triangle shape.

  According to this configuration, only by making the lower end edge of the light guide plate 6 a simple structure (convex structure 62), it is possible to easily suppress volatiles reflected on an object such as a wall surface or a floor surface. .

  Moreover, in the illuminating device 1 which concerns on this Embodiment, the output end surface 65 may have the diffusion structure which diffuses light.

  According to this configuration, since the light emitted from the emission end face 65 is further diffused, it is possible to reduce luminance unevenness and color unevenness.

(Modification 1 of embodiment)
Hereinafter, the illuminating device 1 which concerns on the modification of this Embodiment is demonstrated using FIG.

  FIG. 7 is an image diagram showing light distribution of the light guide plate 6 in the illumination device 1 according to the modification of the present embodiment.

  Although the convex structure 62 of the light guide plate 6 in the embodiment protrudes downward, as shown in FIG. 7, the convex structure 62 of the light guide plate 6 in the modification of the present embodiment faces in the front downward direction. It is different in that it protrudes.

  When the light guide plate 6 is viewed in cross section along a plane defined by the vertical direction and the front-rear direction, the substantially isosceles triangular convex structure 62 is inclined. In the convex structure 62 of the light guide plate 6 in the embodiment, the incident surface 61 and the virtual straight line K are in a substantially parallel relationship, but in the convex structure 62 of the light guide plate 6 in the modification of the present embodiment, the incident surface 61. And the extension line of the imaginary straight line K intersect. The incident surface 61 is substantially parallel to the front-rear direction, but the virtual straight line K defined by the convex structure 62 is inclined with respect to the front-rear direction.

  In addition, a plurality of microprism elements 67 are formed on each of the first emission surface 63 and the second emission surface 64 of the light guide plate 6 of the embodiment, but in the modification of the present embodiment, the second The difference is that a plurality of microprism elements 67 are formed on the exit surface 64.

  Other configurations in the modified example of the present embodiment are the same as those of the lighting device 1 of the embodiment. The same components are denoted by the same reference numerals, and detailed description thereof is omitted. Note that the light guide plate 6 in the modification of the present embodiment may be used with the posture thereof reversed in the front-rear direction.

  The behavior of light emitted from the light source 41 in the illumination device 1 will be described.

  The light emitted from the light source 41 enters from the incident surface 61 of the light guide plate 6 and guides the inside. For example, light incident on the microprism element 67 on the second emission surface 64 is scattered by the microprism element 67. Since the micro-prism element 67 is formed on the second emission surface 64, the light emitted from the micro-prism element 67 tends to go downward. For this reason, the light distribution characteristic in the 2nd output surface 64 has faced the lower back direction. The light scattered by the microprism element 67 is emitted from the first emission surface 63 or reflected by the first emission surface 63.

  Since the micro-prism element 67 is not formed on the first exit surface 63, the light refracted by the first exit surface 63 is less likely to travel downward than the second exit surface 64. For this reason, the light distribution characteristic of the first emission surface 63 is more forward than the second emission surface 64.

  Further, for example, when light that guides the inside enters the emission end face 65, a part of the light is emitted from the emission end face 65, or a part of the light is reflected by the emission end face 65. In such an illuminating device 1, it becomes a light distribution characteristic as shown by the dashed-two dotted line of FIG.

  Also in the modification of the present embodiment, the same operational effects as in the embodiment are exhibited.

(Modification 2 of embodiment)
Hereinafter, the illuminating device 1 which concerns on the modification of this Embodiment is demonstrated using FIG.

  FIG. 8A is a partially enlarged perspective view showing the convex structure 62 of the light guide plate 6 in the lighting device 1 according to the modification of the present embodiment. FIG. 8B is a partially enlarged cross-sectional view showing the convex structure 62 of the light guide plate 6 in the lighting device 1 according to the modification of the present embodiment taken along line BB in FIG.

  Other configurations in the modified example of the present embodiment are the same as those of the lighting device 1 of the embodiment. The same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  The convex structure 62 of the light guide plate 6 in the modification of the present embodiment is composed of a plurality of quadrangular projections (pyramids). As shown in FIG. 8A, the convex structure 62 has a right inclined surface 65c and a left inclined surface 65d in addition to the front emitting end surface 65a and the rear emitting end surface 65b. The right inclined surface 65c is inclined downward from the left side to the right side. The left inclined surface 65d is inclined upward from the left side to the right side. The right inclined surface 65c and the left inclined surface 65d have the same configuration as the front emission end surface 65a and the rear emission end surface 65b.

  In the present embodiment, four rows of convex structures 62 are arranged in the left-right direction in the front-rear direction, but the number of convex structures 62 is not particularly limited.

  Each convex structure 62 satisfies the relationship of the formulas 1 and 2 of the embodiment. Also in the light guide plate 6 in the modification of the present embodiment, if the value obtained by dividing the height d by the thickness d is the same as that of the convex structure 62 of the embodiment, the substantial focal length F is the same.

  In the modification of the present embodiment, the light is diffused not only in the front-rear direction but also in the left-right direction, and the same light distribution characteristics as in the embodiment can be obtained. For this reason, also in the modified example of the present embodiment, the same operational effects as those of the embodiment are obtained.

(Modification 3 of embodiment)
Hereinafter, the illuminating device 1 which concerns on the modification of this Embodiment is demonstrated using FIG.

  FIG. 9 is a partial enlarged cross-sectional view showing the concave structure 72 of the light guide plate 6 in the illumination device 1 according to the modification of the present embodiment.

  The lower end of the light guide plate 6 in the embodiment is a convex structure 62, but the lower end of the light guide plate 6 in the modification of the present embodiment is a concave structure 72 as shown in FIG. ing.

  Other configurations in the modified example of the present embodiment are the same as those of the lighting device 1 of the embodiment. The same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  The concave structure 72 of the modified example of the present embodiment is recessed in a substantially isosceles triangle shape in a cross-sectional view when the light guide plate 6 is cut along a plane defined by the vertical direction and the front-rear direction. That is, the concave structure 72 of the modification of the present embodiment is symmetrical with the convex structure 62 of the embodiment with respect to a plane defined in the left-right direction and the front-rear direction.

  The concave structure 72 has an emission end surface 75 (an example of a concave surface) formed on the lower end surface thereof. The emission end face 75 has a front emission end face 75a and a rear emission end face 75b. The front emission end face 75a is inclined upward from the lower end edge of the first emission face 63 toward the rear side. The rear emission end face 75b is inclined downward from the upper end edge of the front emission end face 75a to the lower end face of the second emission face 64 toward the rear side. The concave structure 72 also has a lens function for diverging or converging light from the emission end face 75, similarly to the convex structure 62 of the embodiment.

  The height h is a distance from the virtual straight line K to the bottom of the concave structure 72 (a straight line where the front emission end face 75a and the rear emission end face 75b intersect). In other words, the height h is the distance from the virtual straight line K to the apex (bottom) of the substantially isosceles triangle (concave structure 72). In this case, the conditions of Expression 8 and Expression 9 are satisfied.

  Also in such an illuminating device 1, the light distribution characteristic similar to embodiment can be acquired.

  In addition, the concave structure 72 in the output end surface 75 of the light guide plate 6 may be arcuate. The arc may be a part of a perfect circle that passes through the first point P1, the second point P2, and the vertex of the concave structure 72. Even in this case, light distribution characteristics similar to those of the illumination device 1 of FIG. 7 are obtained.

  The concave structure 72 at the lower edge of the light guide plate 6 may be a concave shape that is symmetrical to the convex structure 62 of FIGS.

[Function and effect]
Next, the effect of the illuminating device 1 in the modification of this Embodiment is demonstrated.

  As described above, the illumination device 1 according to the present embodiment includes the light source 41 and the light guide plate 6 having the incident surface 61 on which the light of the light source 41 is incident. The light guide plate 6 is formed on the first emission surface 63 that intersects with the incidence surface 61, the second emission surface 64 opposite to the first emission surface 63, and the opposite side to the incidence surface 61, and emits light. And a concave structure 72. A large number of microprism elements 67 are formed on at least one of the first emission surface 63 and the second emission surface 64. And the concave structure 72 has the output end surface 75 which controls light distribution.

  According to this configuration, the light guided through the light guide plate 6 toward the optical axis X direction (downward) is refracted by the emission end surface 75 of the concave structure 72 and intersects the optical axis X direction (front-rear direction). Light distribution. For this reason, compared with the light guide plate 6 of FIG. 10 in which the concave structure 72 does not exist, the light from the output end surface 75 of the light guide plate 6 has little influence on the light distribution on the first output surface 63 and the second output surface 64. Light emitted in the direction of the axis X is weakened.

  Therefore, it is possible to suppress volatility reflected on an object such as a wall surface or a floor surface.

  Moreover, in the illuminating device 1 which concerns on this Embodiment, the light-guide plate 6 has the concave structure 72 in which the output end surface 75 was formed. The concave structure 72 has a lens function for diverging or converging light.

  According to this configuration, only by providing the light guide plate 6 with the concave structure 72 having a lens function, it is possible to suppress volatiles reflected on the object.

  In the illumination device 1 according to the present embodiment, the concave structure 72 extends along the lower end edge of the first exit surface 63 and the lower end edge of the second exit surface 64.

  According to this structure, since the cross section when the light guide plate 6 is cut in a plane defined by the vertical direction and the front and rear direction is substantially the same in any cross section, the light guide plate 6 is easy to manufacture. For this reason, an increase in the manufacturing cost of the light guide plate 6 can be prevented. For example, the light guide plate 6 can be manufactured by simple extrusion molding.

  Moreover, in the illuminating device 1 which concerns on the modification of this Embodiment, the light-guide plate 6 has the concave structure 72 which has the output end surface 65. FIG. When the concave structure 72 is cut in a plane perpendicular to the first emission surface 63 and the incident surface 61, the concave structure 72 represents the focal length of the concave structure 72 as F, and is the target from the concave structure 72. The distance to the irradiation surface of the object is represented by L, the thicknesses of the first exit surface 63 and the second exit surface 64 are represented by d, and the first exit surface 63 and the concave structure 72 are a part of the intersecting line. The height of the concave structure 72 from the virtual straight line K connected by one point P1 and the second point P2, which is a part of the line where the second emission surface 64 and the concave structure 72 intersect, is represented by h, and the light guide plate 6 When the refractive index of n is expressed by n, the conditions of Expressions 10 and 11 are satisfied.

  According to this configuration, it is difficult for volatiles to be reflected on an object such as a wall surface or a floor surface.

  In particular, the light distribution control of the emission end face 75 can be performed without affecting the light distribution of the entire lighting device 1. Further, even when the user views the emission end face 75 from the side (for example, from the front and back), the glare emitted from the emission end face 75 can be reduced. For this reason, it is hard to give a user discomfort.

  As described above, in the illumination device 1 according to the modification of the present embodiment, the concave structure 72 when cut along a plane orthogonal to the first emission surface 63 and the incidence surface 61 has a substantially isosceles triangle shape.

  According to this configuration, only by making the lower end edge of the light guide plate 6 a simple structure (concave structure 72), it is possible to easily suppress volatiles reflected on an object such as a wall surface or a floor surface.

  In the illumination device 1 according to the present embodiment, the emission end face 75 may have a diffusion structure that diffuses light.

  According to this configuration, since the light emitted from the emission end face 75 is further diffused, it is possible to reduce luminance unevenness and color unevenness.

  The other operational effects in the modification of the present embodiment also have the same operational effects as the embodiment.

(Other variations)
As mentioned above, although the illuminating device which concerns on this invention was demonstrated based on Embodiment and the modifications 1-3 of embodiment, this invention is limited to the said embodiment and the modifications 1-3 of embodiment. Is not to be done.

  For example, in the first embodiment and the first and third modifications, the microprism elements are formed on the first emission surface and the second emission surface, but only one of the surfaces may be used.

  Moreover, in the illuminating device of the said embodiment and the modifications 1-3 of embodiment, although either a concave structure or a convex structure is formed in the light guide plate, the structure which combined all is a light guide plate. It may be formed.

  Moreover, in the lighting apparatus of the said embodiment and the modification 1-3 of embodiment, when there are two or more light sources, you may light-emit the light of mutually different color temperature for every light source. In this case, for example, light having a daylight color as the light source can be emitted from a certain light source, and a different light source can have a light bulb color from a different light source. In addition, you may divide | segment a light-guide plate for each light source to light-emit light of mutually different color temperature.

  Moreover, although the illuminating device of the said embodiment and the modifications 1-3 of embodiment is provided so that a light guide plate may be extended in an up-down direction, the light guide plate which made the hollow disk shape is extended in the left-right direction. It may be provided as follows. Specifically, the light guide plate may be formed with a through hole through which a cylindrical main body portion passes. You may arrange | position so that the light source provided in the main-body part may face the entrance plane of a light-guide plate. The microprism element may be formed on the upper surface of the light guide plate. That is, the lighting device may be a downlight.

  In addition, the form obtained by making various modifications conceived by those skilled in the art with respect to the embodiment and the first to third modifications of the embodiment, and the modification of the embodiment and the embodiment without departing from the gist of the present invention Embodiments realized by arbitrarily combining the components and functions in Examples 1 to 3 are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 Illuminating device 6 Light guide plate 41 Light source 61 Incident surface 62 Convex structure 63 1st output surface 64 2nd output surface 65,75 Output end surface (concave surface, convex surface)
67 Micro Prism Element (Prism)
72 Concave structure

Claims (9)

An illumination device comprising a light source and a light guide plate having an incident surface on which light from the light source is incident,
The light guide plate is formed on a first light exit surface intersecting the light incident surface, a second light exit surface opposite to the first light exit surface, and a convex shape for emitting light. Having a surface or a concave surface;
A plurality of prisms are formed on at least one of the first emission surface and the second emission surface,
The concave surface or the convex surface is an illumination device that controls light distribution. The light guide plate has a convex structure in which the convex surface is formed, or a concave structure in which the concave surface is formed,
The lighting device according to claim 1, wherein the concave structure and the convex structure have a lens function for diverging or converging light. The lighting device according to claim 1, wherein the convex surface or the concave surface extends along an edge of the first emission surface and an edge of the second emission surface. The light guide plate has a convex structure having the convex surface,
When the convex structure is cut in a cross section when cut along a plane orthogonal to the first exit surface and the entrance surface,
The convex structure is
The focal length of the convex structure is represented by F,
The distance from the convex structure to the irradiation surface of the object is represented by L,
The thickness from the first exit surface to the second exit surface is represented by d,
The first point that is a part of a line where the first emission surface and the convex structure intersect with each other and a second point that is a part of a line where the second emission surface and the convex structure intersect. The height of the convex structure from the virtual straight line is represented by h,
When the refractive index of the light guide plate is represented by n, the conditions of Formula 1 and Formula 2 are satisfied.

The illuminating device of any one of Claims 1-3. The lighting device according to claim 4, wherein the convex structure when cut along a plane orthogonal to the first emission surface and the incidence surface has a substantially isosceles triangle shape. The light guide plate has a concave structure having the concave surface;
When the concave structure is cut in a plane cut perpendicular to the first exit surface and the entrance surface,
The concave structure is
The focal length of the concave structure is represented by F,
The distance from the concave structure to the irradiation surface of the object is represented by L,
The thickness of the first emission surface and the second emission surface is represented by d,
A virtual straight line connected by a first point that is a part of a line that intersects the first exit surface and the concave structure and a second point that is a part of a line that intersects the second exit surface and the concave structure. The height of the concave structure from h is represented by h,
When the refractive index of the light guide plate is represented by n, the conditions of Equation 3 and Equation 4 are satisfied.

The illuminating device of any one of Claims 1-3. The illumination device according to claim 6, wherein the concave structure when cut along a plane orthogonal to the first emission surface and the incidence surface is a substantially isosceles triangle shape. The lighting device according to claim 4, wherein the convex surface has a diffusion structure for diffusing light. The lighting device according to claim 6, wherein the concave surface has a diffusion structure for diffusing light.

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