JP5861086B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device including a light guide plate.

  2. Description of the Related Art Conventionally, lighting devices that emit light using a light guide plate have been provided. Many light guide plates used for surface light emission are formed in a rectangular plate shape. This type of light guide plate has one surface along the thickness direction as an incident surface, and one surface in the thickness direction as an output surface, and internally reflects light introduced from the incident surface between the other surface in the thickness direction and the output surface. To guide the light. Furthermore, the direction of a part of the light traveling toward the exit surface during the light guide is adjusted so as to enter the exit surface at an angle smaller than the critical angle so that the light is extracted from the exit surface.

  As a configuration for changing the direction of light guided through the light guide plate, a configuration in which a groove is formed on a reflection surface is known (see, for example, Patent Document 1). The groove is recessed in the reflecting surface so as to have a V-shaped cross section. The groove extends in the longitudinal direction of the incident surface for introducing light into the light guide plate, and a plurality of grooves are arranged in parallel in a direction perpendicular to the incident surface. In this configuration, a part of the light reaching the groove while repeating internal reflection in the light guide plate is reflected so as to be incident at an angle smaller than the critical angle with respect to the emission surface and is emitted from the emission surface.

JP 2003-249110 A

  By the way, when controlling the directivity of the light emitted from the light guide plate, an optical improvement sheet for condensing or diffusing the emitted light is currently provided. Moreover, when using the light radiate | emitted from the light-guide plate for the light source of an illumination sign, directivity may be controlled by providing a diffusibility to the display panel in an illumination sign. As described above, in the technology using the optical improvement sheet or the display panel, it is possible to adjust the strength of directivity.

  However, in the optical improvement sheet and the display panel, it is difficult to provide directivity in a desired direction, and thus it is difficult to realize light distribution characteristics that are not isotropic. Further, when an optical improvement sheet or a display panel is used for directivity control, the utilization factor of the emitted light is reduced, leading to a decrease in the emission efficiency.

  The present invention has been made in view of the above-described reasons, and its purpose is to enable directivity control without using an optical improvement sheet or a display panel, and to achieve a desired direction as well as the directivity. It is an object of the present invention to provide an illuminating device that can obtain desired light distribution characteristics without decreasing the emission efficiency.

The present invention, in between the reflective surface is emission surface and the other surface which is one surface in the thickness direction is incident light from the incident surface to the incident surface of the end face on along the formed thickness direction and the left-right direction in a plate shape A light guide plate that emits light from the exit surface by adjusting the direction of a part of the light that goes to the exit surface while internally reflecting and guiding the light, and the longitudinal direction is along the left-right direction of the entrance surface of the light guide plate One end surface in the longitudinal direction is disposed on the upper side of the light guide plate, and light incident from the light introduction surface is formed between one light extraction surface and the other light reflection surface along the longitudinal direction of the incident surface. is internally reflected are paired countercurrent arrangement and the light guide member to emit light, the light introducing surface of the light guide member from the light outlet surface by adjusting the direction of some of the light toward the light outlet surface during the light guide between and a light source you introduce light to the light inlet surface Te, the light guide plate, emitted in the light guide A reflection adjusting unit that adjusts the reflection direction so that the incident angle becomes smaller than the critical angle for a part of the light incident on the reflection surface is provided integrally with the reflection surface, and the direction of the light emitted from the emission surface is adjusted to adjust the incident surface. The light guide member controls the light distribution along the surface orthogonal to the longitudinal direction of the light guide member, and the light guide member has an inclined surface that is inclined so that the distance between the light reflection surface and the light guide surface decreases as the distance from the light introduction surface increases in the longitudinal direction. And a reflection adjustment unit that adjusts the reflection direction so that the incident angle is smaller than the critical angle for a part of the light that is incident on the light extraction surface during light guiding, and is integrally provided on the light reflection surface. The light distribution along the incident surface of the light guide plate is controlled by adjusting the direction of the emitted light, and the reflection adjusting portion of the light guide plate imparts directivity that is obliquely downward with respect to the direction orthogonal to the output surface. the reflection direction was adjusted, the light guide portion Reflection adjustment portion of the is characterized by adjusting the reflection direction so as to impart the directivity of the oblique left or obliquely rightward against the direction perpendicular to the light outlet surface.
In the present invention, the upper surface along the thickness direction and the left-right direction is formed as an incident surface, and the light incident from the incident surface is formed between an exit surface that is one surface in the thickness direction and a reflective surface that is the other surface. A light guide plate that emits light from the exit surface by adjusting the direction of part of the light that travels toward the exit surface while internally reflecting and guiding the light, and the longitudinal direction is along the left-right direction of the entrance surface of the light guide plate In this way, the both end surfaces in the longitudinal direction are arranged on the upper side of the light guide plate, and light incident from each light introduction surface is reflected along the longitudinal direction of the incident surface and the light reflection surface as the other surface. A light guide member that emits light from the light guide surface by adjusting the direction of a part of the light that is directed to the light guide surface while light is internally reflected between the light guide surface and each light introduction surface of the light guide member Two lights that face each other and introduce light into each light introduction surface The light guide plate is integrally provided with a reflection adjustment unit on the reflection surface to adjust the reflection direction so that the incident angle is smaller than the critical angle for a part of the light incident on the emission surface during light guide. The light distribution along the surface perpendicular to the longitudinal direction of the incident surface is controlled by adjusting the direction of the light emitted from the surface, and the light guide member has a light reflecting surface from a predetermined position in the middle portion in the longitudinal direction. It is formed in a shape having two inclined surfaces that are inclined so as to increase the distance from the light output surface toward both ends, and the incident angle of a part of the light incident on the light output surface during light guide is larger than the critical angle. A reflection adjusting unit that adjusts the reflection direction so as to be reduced is provided integrally with the light reflection surface, and the light distribution along the incident surface of the light guide plate is controlled by adjusting the direction of the light emitted from the light guide surface. The reflection adjustment part is diagonally below the direction perpendicular to the exit surface. The reflection direction of the light guide member is adjusted so as to provide a directivity of light, and the reflection adjusting portion of the light guide member is inclined with respect to the light reflected by the right inclined surface of the two inclined surfaces with respect to the direction orthogonal to the light output surface. The reflection direction is adjusted to give left directivity, and the reflection direction is adjusted so that the light reflected by the left inclined surface is given an oblique right directivity with respect to the direction perpendicular to the light exit surface. It is characterized by doing.

  According to the configuration of the present invention, the light distribution along the surface orthogonal to the longitudinal direction of the incident surface is controlled by adjusting the direction of the light emitted from the emission surface in the light guide plate, and the light is emitted from the light output surface in the light guide member. Since the light distribution along the incident surface of the light guide plate is controlled by adjusting the direction of the light to be transmitted, the light emitted from the light guide plate can be directed in a desired direction by using the light guide plate and the light guide member in combination. Thus, there is an advantage that desired light distribution characteristics that are not isotropic can be obtained. Further, since it is not necessary to use an optical improvement sheet or a display panel for imparting directivity, it is possible to obtain desired light distribution characteristics without lowering the emission efficiency.

  Furthermore, since the light guide member controls light distribution along the incident surface of the light guide plate, and the light guide plate controls light distribution along the surface orthogonal to the incident surface, at least one of the light guide member and the light guide plate is used. If a plurality of types having different light distribution characteristics are prepared, an illumination device having different light distribution characteristics can be configured simply by changing the combination of the light guide member and the light guide plate.

Embodiment 1 is shown, (a) is a front view, (b) is a right side view, and (c) is a bottom view. (A) (b) is an enlarged view which shows the structural example of the A section of FIG. (A) (b) is an enlarged view which shows the structural example of the B section of FIG. Embodiment 2 is shown, (a) is a front view, (b) is a right side view, and (c) is a bottom view. The other example same as the above is shown, (a) is a front view, (b) is a right side view, and (c) is a bottom view. Embodiment 3 is shown, (a) is a front view, (b) is a right side view, and (c) is a bottom view. It is a disassembled perspective view of the guide light using the same. It is a perspective view which shows the example of arrangement | positioning of the guide light shown in FIG. The light distribution of the guide light shown in FIG. 7 is shown, (a) is a top view, (b) is a right side view.

(Embodiment 1)
In the present embodiment, as shown in FIG. 1, a rectangular light guide plate 10 and an incident surface that is one surface of the light guide plate 10 (upper surface in FIG. 1A) are arranged along 11. The light guide member 20 and the light source 31 arrange | positioned at the end surface of the longitudinal direction of the light guide member 20 are provided.

  The light guide plate 10 and the light guide member 20 are molded products formed using a translucent synthetic resin, and a light emitting diode is used for the light source 31. However, the type of the light source 31 is not particularly limited.

  As is well known, light is incident on the light guide plate 10 from an incident surface 11 which is one surface of a peripheral surface. Light incident on the light guide plate 10 is guided by repeating internal reflection between the exit surface 12 which is one surface in the thickness direction and the reflective surface 13 which is the other surface, and the exit surface 12 is guided while being guided. The light is emitted from the emission surface 12 by adjusting the direction of a part of the light directed toward.

  The internal reflection at the exit surface 12 during light guide is total reflection, and in this embodiment, the reflection control unit 14 is provided on the reflection surface 13 so that a part of the light incident on the exit surface 12 is emitted from the exit surface 12. Is provided. That is, the reflection adjusting unit 14 adjusts the reflection direction so that the incident angle is smaller than the critical angle for a part of the light incident on the emission surface 12 during light guide. A specific configuration of the reflection adjusting unit 14 will be described later.

  The light guide member 20 is formed in a rod shape or a line shape, and is disposed along the incident surface 11 of the light guide plate 10. Specifically, it is formed in a wedge shape that gradually decreases the vertical width in FIG. 1 from one end in the longitudinal direction to the other end. In the light guide member 20, one end surface in the longitudinal direction formed with a wide vertical width is a light introduction surface 21, and a light source 31 is disposed opposite to the light introduction surface 21.

  The light incident on the light guide member 20 from the light introduction surface 21 undergoes internal reflection between the light deriving surface 22 facing the incident surface 11 of the light guide plate 10 and the light reflecting surface 23 which is the upper surface in FIG. It is guided by repeating. In addition, light is emitted from the light derivation surface 22 by adjusting the direction of part of the light toward the light derivation surface 22 during light guide, and the light emitted from the light derivation surface 22 is incident on the incident surface 11 of the light guide plate 10. Is incident on.

  In the light guide member 20, as in the light guide plate 10, internal reflection at the light guide surface 22 during light guide is total reflection, and a reflection adjusting unit 24 is provided on the light reflection surface 23. The reflection adjusting unit 24 adjusts the reflection direction so that the incident angle is smaller than the critical angle with respect to a part of the light incident on the light guide surface 22 during light guide.

  As the reflection adjusting portion 24 in the light guide member 20, for example, a groove 25 recessed in a V-shaped cross section on the light reflecting surface 23 as shown in FIG. 2A, or a light reflection as shown in FIG. 2B. The diffuse reflection part 26 printed in a dot shape on the surface 23 is used.

  The grooves 25 are extended in a direction orthogonal to the longitudinal direction of the light guide member 20, and a plurality of grooves 25 are provided in the longitudinal direction. The interval and shape (depth and angle of each surface) for forming each groove 25 are appropriately adjusted. Further, the diffuse reflection portions 26 are arranged so as to be appropriately distributed on the light reflection surface 23. The distribution density and shape (size and shape) of the diffuse reflector 26 are adjusted as appropriate.

  The reflection adjusting portion 14 in the light guide plate 10 is similar to the reflection adjusting portion 24 in the light guide member 20, as shown in FIG. 3A, as shown in FIG. As shown in (b), the diffuse reflection part 16 printed in a dot shape on the reflection surface 13 is used.

  The groove 15 extends along the incident surface 11 in the light guide plate 10, and a plurality of grooves 15 are provided in a direction orthogonal to the incident surface 11. The interval and shape (depth and angle of each surface) for forming each groove 15 are appropriately adjusted. Moreover, the diffuse reflection part 16 is arrange | positioned so that it may be distributed in the light reflection surface 23 suitably. The distribution density and shape (size and shape) of the diffuse reflection portion 16 are appropriately adjusted.

  In addition, the structure of the reflection adjustment parts 14 and 24 is not limited to these structures, The other well-known structure is employable.

  By providing the reflection adjusting unit 14 on the reflecting surface 13 and the reflection adjusting unit 24 on the light reflecting surface 23, the reflection adjusting units 14 and 24 are provided for the light incident on the reflecting surface 13 or the light reflecting surface 23. It can be reflected in a different direction from the non-existing part. Therefore, while the light guide plate 10 and the light guide member 20 are guided by internal reflection, the incident angle can be made smaller than the critical angle with respect to a part of the light incident on the light exit surface 12 or the light exit surface 22. Light can be emitted from the surface 12 or the light output surface 22.

  Furthermore, by changing the design conditions of the reflection adjusting units 14 and 24, it is possible to adjust the light emission direction at each part of the emission surface 12 or the light output surface 22 (in FIG. 1, the one-dot chain line indicates the light path). The directional characteristics of light at each part of the exit surface 12 and the light exit surface 22 are indicated by broken arrows and ellipses).

  In the present embodiment, light emitted from the emission surface 12 is provided on the light guide member 20 by controlling the light distribution along the surface perpendicular to the longitudinal direction of the incident surface 11 by the reflection adjusting unit 14 provided on the light guide plate 10. The light distribution along the incident surface 11 is controlled by the reflection adjusting unit 24. That is, the longitudinal direction of the incident surface 11 (left and right direction in FIG. 1A) is the x direction, the direction orthogonal to the incident surface 11 (up and down direction in FIG. 1A) is the y direction, and the thickness direction of the light guide plate 10 is. If the z direction is set, the directivity of the light emitted from the emission surface 12 can be controlled by the light guide plate 10 on the yz plane (the surface perpendicular to the longitudinal direction of the incidence surface 11) as shown in FIG. The directivity characteristics on the zx plane (the surface along the incident surface 1) can be controlled by the light guide member 20 as in 1 (a). In the present embodiment, since the light reflecting surface 23 of the light guide member 20 is inclined with respect to the light guide surface 22, the directivity characteristics on the zx plane can also be adjusted by adjusting the inclination angle. is there.

  As described above, the directivity on the yz plane can be controlled by the light guide plate 10 and the directivity on the zx plane can be controlled by the light guide member 20 for the light emitted from the exit surface 12. Arbitrary light distribution characteristics can be obtained in three dimensions. In particular, since the light guide plate 10 and the light guide member 20 respectively control the directivity characteristics (or light distribution characteristics) on surfaces orthogonal to each other, a three-dimensional light distribution characteristic can be easily designed.

  In other words, if each of the light guide plate 10 and the light guide member 20 has a plurality of types having different light distribution characteristics, various types of light distribution can be achieved by combining the light guide plate 10 and the light guide member 20. It becomes possible to obtain characteristics. The light guide plate 10 does not necessarily have a rectangular plate shape as long as the incident surface 11 is planar.

(Embodiment 2)
In the first embodiment, the light guide member 20 having only one end surface in the longitudinal direction as the light introduction surface 21 is used. However, in this embodiment, the light guide member 20 having both end surfaces in the longitudinal direction as the light introduction surface 21 is used. It is what is used. A light source 31 is disposed opposite to each light introduction surface 21 of the light guide member 20. Furthermore, the reflection surface 23 of the light guide member 20 is configured to increase the distance from the light guide surface 22 toward both ends from a predetermined position (a position where the light guide member 20 is divided into two in the illustrated example) in the middle portion in the longitudinal direction. It is formed in the shape provided with two inclined surfaces inclined in the direction.

  By using the light guide member 20 having the above-described shape, light emission compared to the light guide member 20 of the first embodiment is shown in FIG. Directional deviation can be reduced. That is, the light distribution characteristics can be made substantially symmetrical on the left and right.

  In the illustrated example, the light emitted from the left part of the light guide member 20 in FIG. 4A has right directivity, and the light emitted from the right part of the light guide member 20 has left directivity. Yes. Therefore, the light distribution characteristic of the light emitted from the emission surface 12 of the light guide plate 10 is isotropic as shown in FIG. In other words, the angle dependence of the radiation intensity is small on the zx plane, and it becomes possible to set the characteristic close to omnidirectionality.

  The directivity of the present embodiment can be realized by arranging the optical improvement sheet in the light passage path. However, when the optical improvement sheet is used, light is attenuated by passing through the optical improvement sheet. The radiation efficiency can be increased by adopting a configuration that does not use the optical improvement sheet as in the present embodiment.

  In the configuration example shown in FIG. 4, the right and left of the light emitted from the emission surface 12 is made different by changing the directivity characteristics of the light emitted from the light guide surface 22 of the light guide member 20 between the left part and the right part in FIG. The directionality in the direction is weakened. On the other hand, as shown in FIG. 5A, the light guide member 20 has a directivity in the direction perpendicular to the light guide surface 22, as emitted from the left and right portions of the light guide surface 22 of the light guide member 20. If the reflection adjusting unit 24 is designed, the directivity in the left-right direction (zx plane) can be enhanced as shown in FIG. In the embodiment shown in FIG. 5, the directivity in the vertical direction (yz plane) is also enhanced for the reflection adjusting unit 14 in the light guide plate 10.

  By providing the directivity characteristics as shown in FIG. 5, the luminance in the front direction of the light guide plate 10 (direction perpendicular to the emission surface 12) can be made larger than the luminance in the other direction. That is, the front luminance can be increased. Other configurations and functions are the same as those of the first embodiment.

(Embodiment 3)
As shown in FIG. 6, the present embodiment employs the same configuration as that of the first embodiment, but in the first embodiment, the light guide plate 10 has directivity in the direction orthogonal to the emission surface 12 on the yz plane. On the other hand, in this embodiment, the diagonal directivity in FIG. 6B is given. That is, when the incident surface 11 is the upper surface of the light guide plate 10, the radiation intensity obliquely downward and to the right of the light guide plate 10 is higher than the radiation intensity in the other direction. In other words, the luminance is the highest when the light guide plate 10 is viewed obliquely from below to the right hand.

  As shown in FIG. 7, when the light guide plate 10 is used for the illumination of the guide light 1 or the illumination sign, by providing the directivity as in the present embodiment, the case where the light guide plate 10 is installed at the corner of the building or the like is used. Visibility can be improved. The guide light 1 shown in the figure includes a box-shaped instrument main body 50 that houses a lighting block 41 for lighting a light source 31 (see FIG. 6) and is open on the front surface, and a display panel 51 that covers the front surface of the instrument main body 50. The display panel unit 40 and the holder 60 mounted on the upper part of the display panel unit 40 are configured.

  The light source 31 and the light guide member 20 are accommodated in the holder 60, and the light guide plate 10 is disposed on the back side of the display panel 51 in the display plate unit 40. The display panel 51 is formed of a material having diffuse permeability, and a guide sign such as a letter or a figure indicating the evacuation direction is written on the display panel 51.

  In addition to the lighting block 41, the appliance main body 50 also stores a secondary battery (not shown) that is charged when energized from a power source such as a commercial power source and discharged to light the light source 31 during a power failure. The lighting block 41 and the light source 31 are connected via a connector 42.

  Now, in the guide light 1 shown in FIG. 7, if the left and right sides of the light guide member 20 are interchanged with the configuration shown in FIG. 6, the guide light 1 is viewed from the other direction when seen from the diagonally lower side to the left hand. Higher brightness than usual is obtained. In this configuration, as shown in FIGS. 8 and 9, the guide light 1 is attached to the ceiling surface R at the corner portion surrounded by the three surfaces of the ceiling surface R and the two wall surfaces W in the building. The case where it arrange | positions so that the wall surface W may oppose adjacent to the back surface and left surface of No. 1 is assumed.

  In such an arrangement, the guide lamp 1 is mainly seen from the diagonally lower left hand, and thus, by providing directivity in the light emission direction as in the configuration described above, visibility from the target direction is achieved. Becomes higher. In addition, since the radiation intensity of the light in the other direction may be reduced, the luminous intensity from the light source 31 is reduced when the luminance in the target direction is equal compared to the case where the light is emitted in all directions. This makes it possible to reduce input power. That is, it becomes possible to reduce the battery capacity of the secondary battery or lengthen the lighting time at the time of a power failure.

DESCRIPTION OF SYMBOLS 10 Light guide plate 11 Incident surface 12 Output surface 13 Reflective surface 14 Reflection adjustment part 20 Light guide member 21 Light introduction surface 22 Light extraction surface 23 Light reflection surface 24 Reflection adjustment part 31 Light source

Claims (2)

By internal reflection between the exit surface of the light incident from the incident surface and the end face on along the formed thickness direction and the left-right direction in the plate-shaped incident surface is one surface in the thickness direction and the other surface is a reflective surface A light guide plate that emits light from the exit surface by adjusting the direction of a part of the light that travels to the exit surface during light guide, and an upper side of the light guide plate so that the longitudinal direction is along the left-right direction of the entrance surface of the light guide plate internally reflected between the light reflecting surface is a light outlet surface and the other surface of the light incident from the light introduction surface and the light introducing surface at one end face of the arranged longitudinally to be an aspect in the longitudinal direction of the entrance surface in and the light guide member to emit light from the light outlet surface, are paired direction arranged on the light inlet surface of the light guide member light introducing surface by adjusting the direction of some of the light toward the light outlet surface during the allowed light guide by and a light source you introducing light into,
The light guide plate is integrally provided with a reflection adjusting portion for adjusting a reflection direction so that an incident angle is smaller than a critical angle for a part of light incident on the emission surface during light guide, and is emitted from the emission surface. By adjusting the direction of the light, the light distribution along the surface perpendicular to the longitudinal direction of the incident surface is controlled,
The light guide member is formed of an inclined surface whose light reflecting surface is inclined so that the distance from the light guide surface decreases as the distance from the light introduction surface increases in the longitudinal direction , and light incident on the light guide surface during light guide. A reflection adjustment unit that adjusts the reflection direction so that the incident angle is smaller than the critical angle is provided integrally with the light reflection surface, and the direction of the light emitted from the light output surface is adjusted on the incident surface of the light guide plate. Control the light distribution along the
The reflection adjustment part of the light guide plate adjusts the reflection direction so as to give a directivity that is obliquely downward with respect to the direction orthogonal to the emission surface ,
The illumination device characterized in that the reflection adjusting unit of the light guide member adjusts the reflection direction so as to impart a diagonal leftward or diagonally right directivity with respect to a direction orthogonal to the light guide surface . The upper surface along the thickness direction and the left-right direction is formed as a plate-shaped incident surface, and the light incident from the incident surface is internally reflected between the exit surface that is one surface in the thickness direction and the reflective surface that is the other surface. A light guide plate that emits light from the exit surface by adjusting the direction of a part of the light that travels to the exit surface during light guide, and an upper side of the light guide plate so that the longitudinal direction is along the left-right direction of the entrance surface of the light guide plate The both end surfaces in the longitudinal direction are arranged as light introduction surfaces, and light incident from each light introduction surface is internally formed between a light output surface that is one surface along the longitudinal direction of the incident surface and a light reflection surface that is the other surface. A light guide member that emits light from the light guide surface by adjusting the direction of a portion of the light that is directed to the light guide surface while being reflected and guided, and each light introduction surface of the light guide member that is opposed to each other. Two light sources for introducing light into the light introduction surface,
  The light guide plate is integrally provided with a reflection adjusting portion for adjusting a reflection direction so that an incident angle is smaller than a critical angle for a part of light incident on the emission surface during light guide, and is emitted from the emission surface. By adjusting the direction of the light, the light distribution along the surface perpendicular to the longitudinal direction of the incident surface is controlled,
  The light guide member is formed in a shape having two inclined surfaces whose light reflecting surfaces are inclined so as to increase the distance from the light derivation surface toward the both ends from a predetermined position in the intermediate portion in the longitudinal direction. A reflection adjustment unit that adjusts the reflection direction so that the incident angle becomes smaller than the critical angle for a part of the light incident on the light extraction surface in the light is provided integrally with the light reflection surface, and the direction of the light emitted from the light extraction surface is determined. By controlling the light distribution along the incident surface of the light guide plate,
  The reflection adjustment part of the light guide plate adjusts the reflection direction so as to give a directivity that is obliquely downward with respect to the direction orthogonal to the emission surface,
  The reflection adjusting unit of the light guide member adjusts the reflection direction so as to give the light reflected by the right inclined surface of the two inclined surfaces to the left oblique directivity with respect to the direction orthogonal to the light derivation surface, And the reflection direction is adjusted so that the directivity of diagonal right direction with respect to the direction orthogonal to a light derivation surface may be given to the light reflected on the left inclined surface.

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