JP5285124B2 - Light emitting device and light emitting method - Google Patents

Description

  The present invention relates to a light emitting device and a light emitting method using a light guide plate.

  A light emitting device is known in which a concave portion as a light emitting portion is formed on the back surface of a light guide plate, and light incident from the side surface of the light guide plate is reflected by the reflecting surface (inner surface) of the concave portion and emitted from the front side of the light guide plate (See Patent Document 1).

  According to the light emitting device according to this conventional example, the light from the light source can be reflected in a certain direction to some extent by the reflecting surface of the concave portion, and the intensity of the light can be sufficiently increased. Can be improved.

International Publication No. WO2007 / 123202

  In the above-described conventional example, the reflected light from the reflecting surface of the recess is only visible to the eyes as it is, so there is a limit to the decoration effect.

  The objective of this invention is providing the light-emitting device and the light-emitting method which improved the decoration effect.

  The present invention employs the following means in order to solve the above problems.

That is, the light emitting device of the present invention is
And the back side in a dot-like light emitting portion is formed light guide plate, the light source light is incident from the side of the light guide plate (e.g., LED or laser light source, a fluorescent lamp, incandescent lamp, a light guide for emitting light guided sunlight Body), and
The light emitting portion includes two inner surfaces facing each other through an internal space, which are inclined so as to be directed in a traveling direction of light from the light source toward the surface side of the light guide plate, as reflection surfaces. A light emitting device having a recess ,
The light emitting section includes two inner surfaces facing each other through an internal space, which are inclined so as to go in the traveling direction of light from the light source toward the surface side of the light guide plate, as reflection surfaces. Further having a recess,
When viewed from the back side of the light guide plate, the reflective surface of the first recess and the reflective surface of the second recess are configured to overlap each other .

  According to the present invention, the light emitting unit includes two parallel inner surfaces facing each other through the internal space, which are inclined toward the light traveling direction from the light source toward the surface of the light guide plate, as reflection surfaces. A configuration having a first recess is employed. Therefore, each reflected light reflected by the two reflecting surfaces in the first recess can be interference light. For this reason, light blinks or blinks with changes in the positional relationship (distance and angle) between one of the two reflecting surfaces and the other reflecting surface and the viewpoint. Thereby, a decoration effect can be heightened.

In addition, since the reflection surface of the first recess and the reflection surface of the second recess overlap each other when viewed from the back side of the light guide plate, interference conditions increase, so that the light Blinking or shining, and three or more reflected lights can interfere with each other, so that more varied blinking and shining of light is possible.

Further, another light emitting device of the present invention includes a light guide plate having a dot-like light emitting portion formed on the back surface side, and a light source that makes light incident from the side surface side of the light guide plate,
The light emitting section includes first and second reflection surfaces that include two inner surfaces facing each other through an internal space, which are inclined toward the traveling direction of light from the light source toward the surface side of the light guide plate. Having a recess,
When viewed from the back side of the light guide plate, the reflective surface of the first recess and the reflective surface of the second recess are configured to overlap each other.

  Even when such a configuration is adopted, the reflected light reflected by the two reflecting surfaces in the first recess and the two reflecting surfaces in the second recess can be interference light. Accordingly, the light blinks or shimmers with changes in the positional relationship (distance and angle) between each reflecting surface and the viewpoint. Thereby, a decoration effect can be heightened.

The second recess may be provided at a distance within a coherent length of light from the light source from the first recess .

By doing so, it is possible to make the reflected light from the reflecting surface of the first recess and the reflected light from the reflecting surface of the second recess easily interfere with each other.

Still another invention of the light emitting method is as follows:
A light guide plate in which a dot-like light emitting part is formed on the back surface side, and a light source for making light incident from the side surface side of the light guide plate,
The light emitting section includes first and second reflection surfaces that include two inner surfaces facing each other through an internal space, which are inclined toward the traveling direction of light from the light source toward the surface side of the light guide plate. Having a recess,
When viewed from the back side of the light guide plate, using a light emitting device configured such that the reflective surface of the first recess and the reflective surface of the second recess overlap each other,
The light from the light source is reflected toward the surface side of the light guide plate by the reflection surface of the first recess and the reflection surface of the second recess, respectively.

  In addition, said each structure can be employ | adopted combining as possible.

  As described above, according to the present invention, the decoration effect can be improved.

FIG. 1 is a schematic bottom view of a light emitting device according to Reference Example 1 of the present invention. FIG. 2 is a schematic side view of a light emitting device according to Reference Example 1 of the present invention. FIG. 3 is a schematic cross-sectional view of a light emitting device according to Reference Example 1 of the present invention. FIG. 4 is a schematic plan view of a light emitting device according to Reference Example 1 of the present invention. FIG. 5 is a schematic cross-sectional view of a light emitting device according to Reference Example 2 of the present invention. FIG. 6 is a schematic cross-sectional view of the light-emitting device according to Embodiment 1 of the present invention. FIG. 7 is a schematic cross-sectional view of a light emitting device according to Embodiment 2 of the present invention. FIG. 8 is a schematic cross-sectional view of a light emitting device according to Embodiment 3 of the present invention. FIG. 9 is a schematic plan view of a light-emitting device according to Embodiment 3 of the present invention.

  DETAILED DESCRIPTION Exemplary embodiments for carrying out the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the following embodiments are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

( Reference Example 1)
With reference to FIGS. 1-4, the light-emitting device 100 which concerns on the reference example 1 of this invention is demonstrated. The light emitting device 100 according to this reference example is used as a display or the like, and is a device that displays characters, figures, and the like by light.

<Whole light emitting device>
In particular, the overall configuration of the light emitting device 100 according to this reference example will be described with reference to FIGS. The light emitting device 100 includes a light guide plate 10 made of a transparent material such as acrylic resin, and a light source 20 such as an LED or a laser light source.

In this reference example , the case where the planar shape of the light guide plate 10 is a square is shown, but of course, the light guide plate 10 may adopt various shapes. The front surface 10a of the light guide plate 10 is a flat surface, and the back surface 10b is provided with concave portions 11 as a plurality of dot-like light emitting portions. In this reference example , a total of nine recesses 11 in three rows and three columns are provided. A plurality of light sources 20 are provided on the side surface 10 c side of the light guide plate 10. In this reference example , the light sources 20 are arranged on the extended lines of the recesses 11 in one row (three in total).

  According to the light emitting device 100 configured as described above, light incident from the light source 20 to the inside of the light guide plate 10 is reflected by the reflection surface (inner surface) of the recess 11 at the position of each recess 11. The light is emitted from the surface 10 a side of the light guide plate 10. R in FIG. 4 indicates reflected light visually recognized by a person. Further, in the figure, a line extending in eight directions from the reflected light R indicates that the light is shining, and a thicker line indicates a brighter state.

<Details of recess 11>
In particular, with reference to FIG. 3, the recess 11 according to the present reference example will be described in more detail. 3 is a cross-sectional view taken along the line AA in FIG.

  The recess 11 has a quadrangular shape when viewed from the upper surface side, a triangular cross section parallel to the light traveling direction (see FIG. 3), and a quadrangular cross sectional shape perpendicular to the light traveling direction. Yes. For example, when the light guide plate 10 is an acrylic plate, the concave portion 11 can be easily formed by cutting using a sharp metal blade.

Here, as the reflection surface of the concave portion 11, a first reflection surface 11a that reflects a part of the light L0 that has passed through the inside of the main body of the light guide plate 10 toward the surface 10a side of the light guide plate 10, and a first reflection surface 11a. A second reflecting surface 11b that reflects at least a part of the light L20 transmitted through the reflecting surface 11a toward the surface 10a side of the light guide plate 10; That is, the recessed part 11 is comprised so that two inner surfaces which oppose through an internal space may become a reflective surface. In the present reference example , each of the first reflecting surface 11a and the second reflecting surface 11b is configured so that the angle formed between the back surface 10b of the light guide plate 10 is an obtuse angle larger than 90 °. Yes. That is, the first reflecting surface 11 a and the second reflecting surface 11 b are both inclined surfaces that are inclined so as to be directed in the traveling direction of light from the light source 20 toward the surface 10 a side of the light guide plate 10. Accordingly, the reflected light from the first reflecting surface 11a (hereinafter referred to as the first reflected light L11 for convenience) and the reflected light from the second reflecting surface 11b (hereinafter referred to as the second reflected light L12 for convenience). Are overlapped to cause interference. Here, when the LED is employed as the light source 20, generally, the LED is poor in coherence, but the coherence length is several centimeters, so the distance between the first reflecting surface 11a and the second reflecting surface 11b is small. If it is sufficiently short, the first reflected light L11 and the second reflected light L12 can be made to interfere with each other.

  Note that light from various directions (for example, light that has been repeatedly reflected on the front surface 10a and the back surface 10b of the light guide plate 10) enters the concave portion 11, but in FIG. Only the straight light (light L0) is shown. Further, the reflected light from the first reflecting surface 11a and the reflected light from the second reflecting surface 11b also travel in various directions, but in FIG. 3, for the sake of convenience, the direction travels perpendicular to the surface 10a of the light guide plate 10. Only the light (first reflected light L11 and second reflected light L12) is shown.

<Excellent point of light emitting device 100 according to this reference example >
As described above, according to the light emitting device 100 according to this reference example , the first reflected light L11 from the first reflecting surface 11a interferes with the second reflected light L12 from the second reflecting surface 11b. Therefore, by changing the positional relationship (distance and angle) between the first reflecting surface 11a and the second reflecting surface 11b and the viewpoint, the intensity of the visible light becomes stronger or weaker. FIG. 4A and FIG. 4B show a case where the above positional relationship is different. The former shows a case where the intensity of the visible light is high, and the latter shows a case where the intensity of the visible light is weak. Is shown. Note that the intensity of interference can be controlled (adjusted) by adjusting the angles of the first reflecting surface 11a and the second reflecting surface 11b.

  Therefore, for example, when a person approaches while walking toward the surface 10a of the light guide plate 10 (the same applies to the case where the person moves left and right or up and down), in the process, the intensity of visible light is strong and weak. Are repeated alternately. Therefore, it looks like the light blinks or shines. The same applies when the light emitting device 100 moves. In this way, the reflected light is not visually recognized as it is, but the reflected light appears to blink or shine, so that the decoration effect can be enhanced.

( Reference Example 2)
FIG. 5 shows Reference Example 2 of the present invention. In this reference example , the case where the shape of a recessed part differs from what was shown in the said reference example 1 is shown. Since other basic configurations and operations are the same as those in Reference Example 1, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate. 5 corresponds to the AA cross-sectional view in FIG. 1, similarly to FIG.

The concave portion 12 as the dot-like light emitting portion in this reference example has a quadrangular shape viewed from the upper surface side, a cross-sectional shape parallel to the light traveling direction is a parallelogram as shown in FIG. The cross-sectional shape perpendicular to is a quadrangle. For example, when the light guide plate 10 is an acrylic plate, the recess 12 can be easily formed by laser processing.

Also in this reference example , as in the case of the reference example 1, the first reflecting surface 12a and the second reflecting surface 12b are both formed at an angle greater than 90 ° with the back surface 10b of the light guide plate 10. It is comprised so that it may become an obtuse angle. In this reference example , the first reflecting surface 12a and the second reflecting surface 12b are substantially parallel (in terms of design). That is, the concave portion 12 in the present reference example is configured such that two substantially parallel inner surfaces facing each other through the internal space become reflection surfaces.

As described above, in the present reference example , since the first reflecting surface 12a and the second reflecting surface 12b are substantially parallel, the first reflected light L11 from the first reflecting surface 12a and the second reflecting surface 12b are substantially parallel to each other. Compared with the case of the reference example 1, the second reflected light L12 from the reflecting surface 12b is easily directed in the same direction. Accordingly, the interference efficiency between the first reflected light L11 and the second reflected light L12 is increased, and the reflected light appears to blink or shine further.

(Embodiment 1 )
FIG. 6 shows Embodiment 1 of the present invention. In this embodiment, the structure which devised arrangement | positioning of a recessed part is shown. Since other basic configurations and operations are the same as those in Reference Example 1, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate. 6 corresponds to the AA cross-sectional view in FIG. 1, as in FIG.

In the present embodiment, the shape itself is formed with a first recess 13 that is the same as the recess 11 in Reference Example 1, and the shape itself is formed with a second recess 14 that is the same as the recess 11 in a close position. When viewed from the back surface 10b side to the front surface 10a side of the optical plate 10, the reflection surface of the first recess 13 and the reflection surface of the second recess 14 are configured to overlap each other. As described above, the present embodiment is configured such that a total of four reflecting surfaces of the two reflecting surfaces (inner surface) in the first recess 13 and the two reflecting surfaces in the second recess 14 are arranged at a short distance. ing. A part of the light transmitted through the first recess 13 can enter the second recess 14.

With the configuration as described above, in the present embodiment, any two reflected lights among the four reflected lights from the four reflecting surfaces (inner surfaces), any three reflected lights, or all the reflected lights. Light can interfere. Therefore, the conditions under which interference occurs increase, and the interference efficiency can be further improved as compared with the case of the first and second reference examples . Here, it is preferable that the second recess 14 is disposed so as to be provided at a distance within the coherent length of light from the light source 20 from the first recess 13. By adopting such an arrangement, the light reflected by the reflecting surface of the first recess 13 and the light reflected by the reflecting surface of the second recess 14 can be more reliably interfered with each other. it can.

(Embodiment 2 )
FIG. 7 shows a second embodiment of the present invention. In this embodiment, the configuration shown in Reference Example 2 is adopted for the shape of the recess, and the configuration shown in Embodiment 1 is used for the arrangement of the recess. Since other basic configurations and operations are the same as those in Reference Example 1, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate. 7 corresponds to the AA cross-sectional view in FIG.

In the present embodiment, the shape itself is formed with a first recess 15 that is the same as the recess 12 in Reference Example 2, and the shape itself is formed with a second recess 16 that is the same as the recess 12 in a close position. As in the case of Form 1 , when viewed from the rear surface 10b side to the front surface 10a side of the light guide plate 10, the reflective surface of the first concave portion 15 and the reflective surface of the second concave portion 16 are configured to overlap each other. ing.

By configuring as described above, also in the case of the present embodiment, the same operational effects as those of the first embodiment can be obtained, and as described in Reference Example 2, each reflected light can easily be directed in the same direction. Compared to the case of the first embodiment, the interference efficiency can be further improved.

(Embodiment 3 )
8 and 9 show the third embodiment of the present invention. In this embodiment, the structure which devised arrangement | positioning of a recessed part is shown. Since other basic configurations and operations are the same as those in Reference Example 1, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the present embodiment, the first concave portion 17 having the same shape as the concave portion 11 in Reference Example 1 and the second concave portion 18 having the same shape as the concave portion 11 are provided. The function and effect of the first recess 17 and the function and effect of the second recess 18 are the same as those of the recess 11 in Reference Example 1.

Here, as described in the first reference example , the reflected light from the reflecting surface of the recess travels in various directions. Therefore, the reflected light from the reflecting surface of the first recess 17 also includes the third reflected light L13 and the fourth reflected light L14 that proceed in the direction of the second recess 18 toward the surface 10a side of the light guide plate 10. . Further, the reflected light from the reflecting surface in the second recess 18 also includes the fifth reflected light L15 and the sixth reflected light L16 that proceed in the direction of the first recess 17 toward the surface 10a side of the light guide plate 10. . Therefore, at least any two of the third reflected light L13, the fourth reflected light L14, the fifth reflected light L15, and the sixth reflected light L16 can also interfere. That is, such a phenomenon can be caused by the arrangement relationship between the first recess 17 and the second recess 18.

  FIG. 9 is a schematic plan view of the light emitting device 100 according to the present embodiment, and is a view of the surface 10a side of the light guide plate 10. 9A and 9B show a case where the positional relationship (distance and angle) between the surface 10a of the light guide plate 10 and the viewpoint is different.

  As shown in FIG. 9, when the entire surface 10 a of the light guide plate 10 is viewed, a horizontal stripe pattern appears as a whole due to interference between the reflected lights from the plurality of recesses. As can be seen from FIG. 9 (a) and FIG. 9 (b), the position of the horizontal stripe pattern with high light intensity shifts due to the change in the positional relationship described above, so that the entire horizontal stripe pattern blinks or glitters. looks like. In addition, each reflected light R of the 1st recessed part 17 demonstrated with reference to FIG. 8 and the 2nd recessed part 18 is the reflected light R in FIG. It corresponds to any two adjacent reflected lights R.

  Here, the principle that the reflected lights from the plurality of recesses interfere with each other will be described. The light from the light source 20 generally has a spread angle. Therefore, the light from one light source 20 enters a plurality of recesses. If the light reflected from the plurality of recesses overlaps, interference occurs if the optical path difference is within the coherent length. Thereby, in the whole light-guide plate 10, when it sees from the distance which the reflected light from each recessed part overlaps, a striped pattern is formed.

  For example, in the example shown in FIG. 9, since the light from one light source 20 has a spread, it can be incident on all nine concave portions and reflected. Among these, the light whose distance difference from the light source 20 is within the coherent length causes interference. The same applies to the light from the other two light sources 20. It is considered that the simple sum of the interference results of light from each of the light sources 20 forms a striped pattern.

Here, in the present embodiment, the case where the first concave portion 17 and the second concave portion 18 have the same shape as the concave portion 11 in the reference example 1 has been described. However, these shapes are the concave portions in the reference example 2. Twelve shapes can also be applied.

Also, a combination of a first recess 13 and the first recess 15 shown in and embodiment 2 a combination of a second recess 14 second recess 16 shown in the first embodiment, a plurality Also by arranging them at the locations, as shown in the present embodiment, when the entire surface 10a of the light guide plate 10 is viewed, a striped pattern can be formed as a whole.

  And about the arrangement | positioning of these recessed parts (light emission part), when it sees from the back surface 10b side of the light-guide plate 10, each recessed part is light from the light source 20 from another recessed part (at least one other recessed part). It is preferable to provide the distance within the coherent length. By adopting such an arrangement, the difference between the distance from the light source 20 to one recess and the distance to another recess can be made within the coherent length, and the reflected light from each recess can be more reliably obtained. Can be interfered with.

(Other)
In the above embodiment, only the example in which the recesses are arranged in 3 rows and 3 columns is shown, but in the display, characters, figures, patterns, and the like can be represented by the arrangement of the plurality of recesses. Further, by making the light colors of the plurality of light sources 20 different from each other, the decoration effect can be further enhanced.

  In the above-described embodiment, the case where the reflecting surface (inner surface) of the concave portion that reflects light is configured as a flat surface, but the reflecting surface is configured as a curved surface as long as the condition that the reflected lights interfere with each other is satisfied. May be. Further, the planar shape of the recess is not limited to a square (square). Furthermore, in the above-described embodiment, the case where all the concave portions have bottoms is shown, but the concave portions may be configured by through holes penetrating from the back surface 10b of the light guide plate 10 to the front surface 10a.

  In addition, as a material of the light guide plate 10, a material that can be bent like polyurethane may be adopted.

  DESCRIPTION OF SYMBOLS 10 ... Light guide plate, 11 ... Recessed part, 11a ... 1st reflective surface, 11b ... 2nd reflective surface, 20 ... Light source, 100 ... Light-emitting device

Claims (4)

Includes a back side in a dot-like light emitting portion is formed light guide plate, and a light source light is incident from the side of the light guide plate,
The light emitting portion includes two inner surfaces facing each other through an internal space, which are inclined so as to be directed in a traveling direction of light from the light source toward the surface side of the light guide plate, as reflection surfaces. A light emitting device having a recess ,
The light emitting section includes two inner surfaces facing each other through an internal space, which are inclined so as to go in the traveling direction of light from the light source toward the surface side of the light guide plate, as reflection surfaces. Further having a recess,
A light emitting device configured such that when viewed from the back side of the light guide plate, the reflective surface of the first recess and the reflective surface of the second recess overlap each other . Includes a back side in a dot-like light emitting portion is formed light guide plate, and a light source light is incident from the side of the light guide plate,
The light emitting section includes first and second reflection surfaces that include two inner surfaces facing each other through an internal space, which are inclined toward the traveling direction of light from the light source toward the surface side of the light guide plate. Having a recess,
A light emitting device configured such that when viewed from the back side of the light guide plate, the reflective surface of the first recess and the reflective surface of the second recess overlap each other. The second recess, the light emitting device according to claim 1 or 2, characterized in that from said first recess is provided within a distance of a coherence length of the light from the light source. Includes a back side in a dot-like light emitting portion is formed light guide plate, and a light source light is incident from the side of the light guide plate,
The light emitting section includes first and second reflection surfaces that include two inner surfaces facing each other through an internal space, which are inclined toward the traveling direction of light from the light source toward the surface side of the light guide plate. Having a recess,
When viewed from the back side of the light guide plate, using a light emitting device configured such that the reflective surface of the first recess and the reflective surface of the second recess overlap each other,
A light emitting method, wherein light from the light source is reflected toward the surface side of the light guide plate by the reflecting surface of the first recess and the reflecting surface of the second recess, respectively.

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