JP6164520B2 - Surface light emitting device and display device - Google Patents

Description

  The present invention relates to a surface light-emitting device that emits light in a planar shape, and more particularly to a surface light-emitting device that has different light emission characteristics depending on a region on a light-emitting surface.

  Development of a surface light emitting device that emits light in a planar shape is underway. For example, Patent Document 1 discloses a surface light-emitting device having a light guide plate and a light source disposed on the side of the light guide plate. This surface light-emitting device is used as a shelf board and illuminates a product arranged on the shelf board.

JP 2003-151337 A

  However, in the surface light emitting device disclosed in Patent Document 1, an object to be illuminated such as a product is illuminated with diffused light or illumination light having a specific directivity. According to the illumination disclosed in Patent Document 1, it may be possible to illuminate an object to be illuminated brightly, but it is difficult to impart unexpectedness and design to the illumination method itself. As a result, the value of an object to be illuminated such as a product cannot be sufficiently increased by illumination with the surface light emitting device.

  The inventor of the present invention has developed a surface light-emitting device having different light emission characteristics depending on the region on the light-emitting surface as a result of repeated studies in consideration of such points. And this inventor discovered that according to the illumination from such a surface light-emitting device, it became possible to show the eye catching effect outstandingly compared with the conventional illuminating device. The present invention is based on such knowledge of the present inventors, and an object of the present invention is to provide a surface light emitting device having different light emission characteristics depending on a region on a light emitting surface.

A surface light emitting device according to the present invention includes:
A light guide plate including a pair of main surfaces and a side surface located between the pair of main surfaces;
A light source disposed facing the side surface of the light guide plate located on one side in the first direction;
A first optical sheet disposed to face one main surface of the light guide plate and including a prism surface;
A second optical sheet having a prism surface, which is disposed to face one main surface of the light guide plate at a position shifted from the first optical sheet along the plate surface of the light guide plate,
The first optical sheet and the second optical sheet differ in at least one of the shape of the prism surface and the direction in which the prism surface faces, so that the light transmitted through the first optical sheet is the highest. The direction in which the luminance is exhibited is different from the direction in which the light transmitted through the second optical sheet exhibits the maximum luminance.

In the surface light emitting device according to the present invention,
The first optical sheet is a plurality of unit prisms arranged in the one direction to form the prism surface, and each of the first optical sheets is located on one side in the first direction; A plurality of unit prisms having a second surface located on the other side opposite to the one side in the direction,
The second optical sheet is a plurality of unit prisms arranged in the one direction to form the prism surface, each of the first surfaces being located on the one side in the first direction; A plurality of unit prisms having a second surface located on the other side in one direction,
The inclination of the second surface may be different between the unit prism of the first optical sheet and the unit prism of the second optical sheet.

  In the surface light emitting device according to the present invention, one of the prism surface of the first optical sheet and the prism surface of the second optical sheet is disposed to face the light guide plate, and the prism surface of the first optical sheet The other of the prism surfaces of the second optical sheet may face the side opposite to the light guide plate.

  In the surface light emitting device according to the present invention, the prism surface of the first optical sheet may face the light guide plate side, and the prism surface of the second optical sheet may face the light guide plate side.

A surface light-emitting device according to the present invention is arranged to face one main surface of the light guide plate at a position displaced from the first optical sheet and the second optical sheet along the plate surface of the light guide plate, and a prism surface A third optical sheet having
At least one of the shape of the prism surface and the direction in which the prism surface faces is different between the third optical sheet and the first optical sheet, so that the light transmitted through the third optical sheet is the highest. The direction in which the luminance is exhibited is different from the direction in which the light transmitted through the first optical sheet exhibits the maximum luminance,
The third optical sheet and the second optical sheet differ in at least one of the shape of the prism surface and the direction in which the prism surface is directed, so that the light transmitted through the third optical sheet is the highest. The direction in which the luminance is exhibited may be different from the direction in which the light transmitted through the second optical sheet exhibits the maximum luminance.

A surface light-emitting device according to the present invention comprises:
Support means for removably supporting the first optical sheet and the second optical sheet at predetermined positions with respect to the light guide plate and the light source;
A third optical sheet having a prism surface having a shape different from both the prism surface of the first optical sheet and the prism surface of the second optical sheet;
The support means may be configured to support the third optical sheet instead of at least one of the first optical sheet and the second optical sheet.

  The display device according to the present invention includes any of the surface light emitting devices according to the present invention described above.

  According to the surface light emitting device according to the present invention, the first and second optical sheets in which at least one of the shape of the prism surface and the direction in which the prism surface faces are different from each other are disposed at a position facing the light guide plate. In addition, the direction in which the light transmitted through the first optical sheet exhibits the highest luminance is different from the direction in which the light transmitted through the second optical sheet exhibits the highest luminance. According to such a surface light emitting device, it is possible to achieve an excellent eye catching effect, that is, an effect of attracting the eyes of the observer.

FIG. 1 is a perspective view showing an exhibition apparatus including a surface light emitting device for explaining an embodiment according to the present invention. FIG. 2 is a cross-sectional view showing the surface light emitting device of the display device in a cross section taken along line II-II in FIG. FIG. 3 is a plan view schematically showing a part of the surface light emitting device. FIG. 4 is a side view for explaining the operation of the surface light emitting device and the display device. FIG. 5 is a side view for explaining the operation of the surface light emitting device and the display device. FIG. 6 is a diagram for explaining a modification of the surface light emitting device, and is a plan view schematically showing a part of the surface light emitting device. FIG. 7 is a perspective view showing a part of the surface light emitting device. FIG. 8 is a cross-sectional view showing the surface light emitting device in a cross section taken along line VIII-VIII in FIG. 1. FIG. 9 is a cross-sectional view showing the surface light emitting device in a cross section taken along line IX-IX in FIG. FIG. 10 is a cross-sectional view showing a modification of the surface light emitting device in the same cross section as FIG. 8 and FIG. 9.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for ease of understanding, the scale and the vertical / horizontal dimensional ratio are appropriately changed and exaggerated from those of the actual ones.

  1 to 10 are diagrams for explaining an embodiment of the present invention. 1 to 10 show examples in which the surface light emitting device according to the present invention is incorporated in a shelf board of an exhibition apparatus. However, the surface light-emitting device of the present invention is not limited to being incorporated in a shelf board, or is not limited to being used in an exhibition apparatus, and can be applied to various uses.

  In the present specification, the terms “sheet”, “plate”, and “film” are not distinguished from each other only based on the difference in names. For example, “sheet” is a concept that includes a member that can be called a plate or a film. Therefore, “optical sheet” is distinguished from a member called “optical plate” or “optical film” only by a difference in name. I don't get it.

  In addition, “sheet surface (plate surface, film surface)” means a target sheet-like member (plate-like) when the target sheet-like (plate-like, film-like) member is viewed as a whole and globally. It refers to the surface that matches the plane of the member. In the present embodiment described below, the light emitting surface of the surface light emitting device, the plate surface of the light guide plate described later, and the sheet surface of each optical sheet described later are parallel.

  Furthermore, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, etc. Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

  Furthermore, “prism”, “lens”, and “optical element” used in the present specification are elements having a function of changing the traveling direction of light by applying an optical action such as refraction or reflection to the light. It is not distinguished from each other based only on the difference in designation. Therefore, for example, a “prism surface” cannot be distinguished from a “lens surface” only by a difference in name. The “unit lens” is a unit element constituting a prism or a prism surface, and is not distinguished from the “unit lens”, “unit optical element”, or the like only by a difference in name.

  As shown in FIG. 1, the display device 10 includes a main frame 17 as a frame material and two shelf boards 15 and 16 supported by the main frame 17. The main frame 17 is configured as a plate-like member in the illustrated example, and supports the shelf plate 15 and the shelf plate 16 while being spaced apart in the vertical direction. The shelf 16 disposed on the lower side is mainly used for placing an exhibit. The shelf board 15 arrange | positioned at the upper side contains the surface light-emitting device 20 which light-emits light planarly. As shown in FIG.4 and FIG.5, the surface light-emitting device 20 has the surface of the side facing the shelf board 16 of the shelf board 15 as the light emission surface 20a. Therefore, the surface light emitting device 20 incorporated in the shelf board 15 can illuminate the exhibit placed on the shelf board 16.

  In one embodiment described below, the surface light emitting device 20 faces the light guide plate 40, the light source 30 disposed facing the light incident surface 43 of the light guide plate 40, and the light exit surface 41 of the light guide plate 40. The plurality of optical sheets 50 and 60 are arranged. The plurality of optical sheets 50 and 60 are arranged at positions shifted from each other along the plate surface of the light guide plate 40. Therefore, the light emitted from the light guide plate 40 enters different optical sheets 50 and 60 depending on which region of the light output surface 41 of the light guide plate 40 is emitted. In general, the luminance angle distribution on the light exit surface 41 of the light guide plate 40 has a tendency to be substantially the same distribution among the regions along the light guide direction of the light guide plate 40, and the light guide plate 40 has the same distribution. There is a tendency that the distribution is substantially the same between the regions along the direction orthogonal to the light guide direction. For this reason, by exhibiting different deflection functions depending on the different optical sheets 50 and 60, the light emission characteristic on the light emitting surface 20 a of the surface light emitting device 20 is on the light emitting surface 20 a which is parallel to the plate surface of the light guide plate 40. It depends on the area.

  In the example shown in FIGS. 2 to 5, the surface light emitting device 20 has the juxtaposed first optical sheet 50 and the second optical sheet 60 at a position facing the light exit surface 41 of the light guide plate 40. The first optical sheet 50 and the second optical sheet 60 have prism surfaces 50a and 60a having different shapes. As a result, the light transmitted through the first optical sheet 50 has a light emission characteristic different from that of the light transmitted through the second optical sheet 60, for example, in a direction different from the luminance peak of the light emitted from the second optical sheet 60. Has a luminance peak. As a more specific index, as shown in FIG. 1, the highest luminance angle distribution (luminance direction distribution) obtained by measuring the luminance on the light emitting surface 20a facing the first optical sheet 50 from various directions. The direction (namely, the optical axis) pd1 exhibiting the following luminance is the highest in the luminance angle distribution (luminance direction distribution) obtained by measuring the luminance on the light emitting surface 20a facing the second optical sheet 60 from various directions. It becomes non-parallel to the direction (namely, optical axis) pd2 which exhibits the brightness | luminance which becomes.

  According to such a surface light emitting device 20, it is possible to achieve an excellent eye catching effect, that is, an effect of attracting the eyes of the observer. As a result, it is possible to increase the value of the illuminated object illuminated by the surface light emitting device 20, for example, to stimulate purchase intention for the illuminated object or to improve the aesthetic evaluation of the illuminated object.

  Next, an example of the surface light emitting device 20 capable of realizing the above light emission characteristics will be described in detail with reference to a specific example illustrated. The illustrated surface light emitting device 20 is disposed to face a pair of main surfaces 41 and 42 and a light guide plate 40 having a side surface connecting the pair of main surfaces 41 and 42, and a part of the side surface of the light guide plate 40. The light source 30 includes a first optical sheet 50 and a second optical sheet 60 that are disposed to face one main surface forming the light exit surface 41 of the light guide plate 40.

  As can be understood from FIG. 1, the surface light emitting device 20 has a quadrangular outline in plan view. As shown in FIG. 3, the light guide plate 40 is also formed as a plate-like member having a pair of main surfaces that are quadrangular, particularly rectangular. The light guide plate 40 includes a pair of side surfaces extending in the second direction d2 facing the first direction d1 and intersecting the first direction d1, and a pair of side surfaces extending in the first direction d1 and facing the second direction d2. , Including four sides. Of the side surfaces of the light guide plate 40, the side surface located on one side of the pair of side surfaces facing the first direction d <b> 1 forms the light incident surface 43 of the light guide plate 40. The light source 30 is disposed at a position facing the light incident surface 43 of the light guide plate 40. The light incident on the light guide plate 40 from the light incident surface 43 is directed toward the opposite surface 44 facing the light incident surface 43 along the first direction d1 that is the light guide direction, and generally along the first direction d1. The inside is guided.

  As the light guide plate 40, various known light guide plates can be used. The illustrated light guide plate 40 includes a base 46 formed in a plate shape, and a plurality of unit optical elements 47 formed on the surface of the base 46 opposite to the optical sheets 50 and 60. Yes. The base 46 is a flat plate portion having a pair of parallel main surfaces. The plurality of unit optical elements 47 are arranged in the first direction d1. Each unit optical element 47 extends linearly on the base 46 in a direction intersecting the first direction d1. In particular, in the illustrated example, the plurality of unit optical elements 47 are arranged side by side on the base 46 in the first direction d1 without a gap. Therefore, the back surface 42 of the light guide plate 40 is an uneven surface formed from the reflection surface 42 a and the connection surface 42 b that form the surface of the unit optical element 47. Each unit optical element 47 extends linearly along a direction orthogonal to the first direction d1, that is, along the second direction d2. Furthermore, each unit optical element 47 is formed in a columnar shape, and has the same cross-sectional shape along the longitudinal direction. In the illustrated example, the plurality of unit optical elements 47 are configured identically.

  In the cross section parallel to both the arrangement direction of the unit optical elements 47 and the normal direction nd of the base 46, each unit optical element 47 is formed in a triangular shape with one side positioned on the base 46. The unit optical element 47 has a reflection surface 42a formed as a long side and a connection surface 42b formed as a short side. The reflective surface 42a has a function of bending the traveling direction of the light so that the traveling direction of the light traveling in the light guide plate 40 is reduced with respect to the normal direction nd to the light guiding plate 40. It promotes that light is emitted from the light guide plate 40 via the light exit surface 41. On the other hand, the connection surface 42b is a stepped surface that connects two adjacent reflection surfaces 42a, and is not particularly expected to have an optical function with respect to light traveling in the light guide plate 40. The inclination angle θb (see FIGS. 7 to 9) of the reflecting surface 42a with respect to the light guide direction can be set to a relatively small value, for example, 0.2 ° to 2 °. On the other hand, the inclination angle of the connection surface 42b with respect to the light guide direction is set to a relatively large value, typically 90 °.

  The dimensions of the light guide plate 40 having the above-described configuration can be set as follows as an example. As a specific example of the unit optical element 47, the width Wb (see FIGS. 7 to 9) along the plate surface of the light guide plate 40 can be 10 μm or more and 500 μm or less, and the normal direction to the plate surface of the light guide plate 40 A height Hb (see FIGS. 7 to 9) from the base 46 of the unit optical element 47 along nd can be set to 1 μm or more and 50 μm or less. Moreover, the thickness of the base 46 can be 0.1 mm-6 mm. The light guide plate 40 having such a configuration is formed by extrusion molding using a resin molding sheet or by molding the first unit element 61 and the unit optical element 47 made of ionizing radiation resin on a base material. Can be produced.

  According to the dimensions and shape of the light guide plate 40 exemplified here, the normal direction nd of the light guide plate 40 is 0 °, and the light incident surface in the light guide direction from the normal direction nd of the light guide plate 40, that is, the first direction d1. The angle when inclined toward the 43 side becomes a negative value, and the angle when inclined toward the opposite surface 44 side in the light guide direction from the normal direction nd of the light guide plate 40 becomes a positive value. The angular distribution of luminance obtained by measuring the luminance on the light exit surface 41 of the light guide plate 40 from each direction in a plane parallel to both the light guide direction and the normal direction nd of the light guide plate 40 In FIG. 5, the peak angle has the maximum brightness between 65 ° and 80 °, and the range of the exemplified dimensions is narrowed so that the peak angle has the maximum brightness between 65 ° and 75 °. be able to.

  The light source 30 may be configured in various modes such as a fluorescent lamp such as a linear cold cathode tube, a point LED (light emitting diode), an incandescent lamp, and the like. In the illustrated example, as shown in FIGS. 3 and 7, the light source 30 includes a large number of point-like light emitters arranged side by side along the longitudinal direction of the light incident surface 43, that is, along the second direction d <b> 2. 31, specifically, a plurality of light emitting diodes (LEDs).

  Next, the optical sheets 50 and 60 will be described. The first optical sheet 50 and the second optical sheet 60 are arranged such that the sheet surfaces thereof are parallel to the plate surface of the light guide plate 40. The second optical sheet 60 is disposed along the plate surface of the light guide plate 40 so as to be adjacent to the first optical sheet 50. In the present embodiment, as shown in FIG. 3, each of the first optical sheet 50 and the second optical sheet 60 is either one of the regions formed by equally dividing the region facing the light source 30 in the second direction d2. It is arranged to face. Each of the optical sheets 50 and 60 is formed as a plate-like member having a quadrangular shape, particularly a rectangular shape in plan view. In FIG. 3, the first optical sheet 50 and the second optical sheet 60 are shifted from the light guide plate 40 for ease of understanding and convenience.

  The first optical sheet 50 and the second optical sheet 60 have prism surfaces 50a and 50b, respectively, and specify a traveling direction of a lot of light emitted from one main surface 41 of the light guide plate 40. It is possible to exhibit a deflection function of deflecting in a direction within an angular range that is narrowed to a certain extent from the center. As shown in FIGS. 7 to 9, each optical sheet 50, 60 has a sheet-like main body 52, 62 and one direction (arrangement direction) on the sheet surface, specifically, the light guide plate 40 described above. A plurality of unit prisms 55 and 65 arranged in a first direction d1 connecting the light incident surface 43 and the opposite surface 44. The unit prisms 55 and 65 are arranged on the main body portions 52 and 62, and form prism surfaces 50a and 60a.

  In the illustrated embodiment, the unit prisms 55 and 65 extend linearly on a sheet surface of the optical sheets 50 and 60 in a second direction d2 orthogonal to the arrangement direction d1. The unit prisms 55 and 65 are positioned on one side in the first direction d1, more specifically, on the other side in the first direction d1 and the first surfaces 55a and 65a positioned on the side closer to the light source 30. Second surfaces 55b and 65b. The unit prisms 55 and 65 are arranged on the main body portions 52 and 62 without any gaps, and the prism surfaces 50a and 60a of the optical sheets 50 and 60 are the first surfaces 55a and 55b and the second surfaces of the unit prisms 55 and 65, respectively. 65a, 65b. The unit prisms 55 and 65 shown in the figure have a triangular cross-sectional shape in a cross section orthogonal to the longitudinal direction.

  In addition, the dimension and shape of the optical sheets 50 and 60 can be appropriately set in consideration of the dimension and shape of the light guide plate 40. As an example, in the combination with the light guide plate 40 having the above-described size and shape, the size and shape of the optical sheets 50 and 60 can be set as follows. First, the width Wa (see FIGS. 7 to 9) of the unit prisms 55 and 65 can be set to 10 μm or more and 200 μm or less. Further, the projection height Ha (see FIGS. 7 to 9) of the unit prisms 55 and 65 from the main body portions 52 and 62 along the normal direction nd to the sheet surface of the optical sheets 50 and 60 is 7 μm or more and 150 μm or less. can do. On the other hand, the thickness of the main body 74 can be set to 0.01 mm to 1 mm. Next, the second surfaces 55b and 65b of the unit prisms 55 and 65 are intended to change the traveling direction of the light by reflecting or refracting the light from the light guide plate, as will be described later. And, in a plane parallel to both the first direction d1 and the normal direction nd of the light guide plate 40, the inclination angle θa (see FIGS. 7 to 9) of the second surfaces 55b and 65b with respect to the first direction d1 is 35. It can be set to be no less than 75 ° and no more than 75 °.

  As described above, the first optical sheet 50 and the second optical sheet 60 are the same in that they have prism surfaces 50a and 60a. In particular, in the present embodiment, the sheet-like main body portions 52 and 62, It is the same in that it has unit prisms 55 and 65 provided on the main body portions 52 and 62. However, the first optical sheet 50 and the second optical sheet 60 are different from each other in at least one of the shape of the prism surfaces 50a and 60a and the direction in which the prism surfaces 50a and 60a face. Due to this difference, the deflection functions exhibited by the prism surfaces 50a and 60a of the first optical sheet 50 and the second optical sheet 60 are different, and the light transmitted through the first optical sheet 50 has the highest luminance as shown in FIG. And the direction pd2 in which the light transmitted through the second optical sheet 60 exhibits the maximum luminance are non-parallel.

  Here, the difference in the shape of the prism surfaces 50a and 60a occurs when the shape of the unit prisms 55 and 65 forming the prism surfaces 50a and 60a is different between the first optical sheet 50 and the second optical sheet 60. As will be described later, the deflection function on the prism surfaces 50a and 60a can be exerted largely depending on the reflection or refraction on the second surfaces 55b and 65b of the unit prisms 55 and 65. For this reason, the inclination or direction of the second surfaces 55b and 65b, more precisely, along both the first direction d1 that is the arrangement direction of the unit prisms 55 and 65 and the normal direction nd of the optical sheets 50 and 60. If the inclination angle θa of the second surfaces 55b and 65b with respect to the first direction d1 in the in-plane is different between the first optical sheet 50 and the second optical sheet 60, the light guide plate 40 is directed in the same direction. Different deflection functions can be exerted on the emitted light. As a result, as shown in FIG. 1, the direction pd1 in which the light transmitted through the first optical sheet 50 exhibits the highest luminance and the direction pd2 in which the light transmitted through the second optical sheet 60 exhibits the highest luminance become nonparallel.

  In the illustrated embodiment, the angle θa formed by the second surface 55b of the unit prism 55 forming the prism surface 50a of the first optical sheet 50 with respect to the first direction d1 is the prism surface 60a of the second optical sheet 60. Is different from the angle θa formed by the second surface 65b of the unit prism 65 with respect to the first direction d1. As shown in FIGS. 8 and 9, the angle θa formed by the second surface 55b of the unit prism 55 of the first optical sheet 50 with respect to the first direction d1 is the second surface of the unit prism 65 of the second optical sheet 60. 65b is larger than an angle θa formed with respect to the first direction d1. That is, in the illustrated embodiment, the shapes of the prism surfaces 50 a and 60 a are different between the first optical sheet 50 and the second optical sheet 60.

  On the other hand, the directions in which the prism surfaces 50a and 60a face are different from each other when the prism surface of one optical sheet faces the light guide plate 40 and the prism surface of the other optical sheet faces the side away from the light guide plate 40. It is that you are. That is, when the surface on which the prism surface is provided among the pair of main surfaces of the main body is different between the two optical sheets, the orientations of the prism surfaces 50a and 60a are different. As shown in FIGS. 7-9, in this Embodiment, in any of the 1st optical sheet 50 and the 2nd optical sheet 60, on the surface of the side facing the light-guide plate 40 of the main-body parts 52 and 62, Unit prisms 55 and 65 are formed. As a result, between the first optical sheet 50 and the second optical sheet 60, the directions in which the prism surfaces 50a and 60a face are both on the light guide plate 40 side, and there is no difference in this respect.

  In addition, as shown in FIG. 2, the surface light emitting device 20 according to the present embodiment faces the reflecting plate 33 disposed facing the back surface 42 of the light guide plate 40 and the light guide plate 40 of the optical sheets 50 and 60. And a diffusion plate 34 disposed on the non-side. The reflection plate 33 is a member for reflecting the light leaking from the back surface 42 of the light guide plate 40 and making it enter the light guide plate 40 again. The reflection plate 33 is composed of a white scattering reflection sheet, a sheet made of a material having a high reflectance such as metal, a sheet containing a thin film (for example, a metal thin film) made of a material having a high reflectance as a surface layer, and the like. obtain. The diffusion plate 34 is a member for diffusing the light transmitted through the optical sheets 50 and 60. The diffusing plate 34 can be composed of a sheet having irregularities formed on the surface, a sheet having a main part and a diffusion component dispersed in the main part, and the like.

  In addition, the surface light emitting device 20 is disposed on the side of the reflecting plate 33 that does not face the light guide plate 40, the reinforcing plate 35 and the surface film 36 that are disposed on the side that does not face the light guide plate 40, and on the side that does not face the optical sheets 50 and 60 of the diffusion plate 34. The reinforcing plate 37 and the surface film 38 may be further included. The reinforcing plates 35 and 37 are made of, for example, glass, and reinforce the surface light emitting device 20 that functions as the shelf plate 15. The surface films 36 and 38 are portions that form both surfaces of the surface light emitting device 20. Therefore, the surface films 36 and 38 are configured as a hard coat layer imparted with scratch resistance, a decorative layer subjected to printing or the like for improving the design of the surface light emitting device 20 and the display device 10, and the like. Is done. The surface film 38 facing the shelf plate 16 disposed on the lower side forms the light emitting surface 20 a of the surface light emitting device 20.

  By the way, the light guide plate 40, the first optical sheet 50, the second optical sheet 60, the reflection plate 33, the diffusion plate 34, the reinforcing plate 35, the surface film 36, the reinforcing plate 37, and the surface film 38 described above are supported by the support means 25. Thus, the surface light emitting device 20 or the shelf board 15 is formed in a predetermined positional relationship. As shown in FIG. 2, the support means 25 includes a pair of side support frames 26 that are spaced apart in the second direction d2, a center support frame 27 that is positioned between the pair of side support frames 26, have. The pair of side support frames 26 and the center support frame 27 are connected to each other at least at one end in the first direction d1 so that the relative positional relationship can be maintained.

  As shown in FIG. 2, the light guide plate 40, the reflection plate 33, the diffusion plate 34, the reinforcing plate 35, the surface film 36, the reinforcing plate 37, and the surface film 38 are each in the second direction by the pair of side support frames 26. Both edges at d2 are supported. The first optical sheet 50 is supported at both edges in the second direction d2 by the side support frame 26 positioned on the side corresponding to the center support frame 27. Similarly, the second optical sheet 60 is supported at both edges in the second direction d2 by the side support frame 26 located on the side corresponding to the center support frame 27.

  In addition, you may make it the support means 25 support each member so that removal is possible. For example, at least one of the surface film 36 and the surface film 38 may be changed according to the article displayed on the display device 10. In addition, it is preferable that the first optical sheet 50 and the second optical sheet 60 are detachably supported by the support means 25. Furthermore, it is preferable that the first optical sheet 50 and the second optical sheet 60 can be supported so that the direction in which the prism surfaces 50a and 60a face can be changed, that is, in the opposite direction. According to such an example, the light emission characteristics of the surface light emitting device 20 are adjusted by appropriately selecting and using an optical sheet from a plurality of optical sheets, or by changing the orientation of the prism surface of the optical sheet. And more preferable illumination can be realized.

  Next, the operation of the surface light emitting device 20 and the display device 10 configured as described above will be described.

  First, as shown in FIGS. 8 and 9, the light emitted from the group of light emitters 31 forming the light source 30 enters the light guide plate 40 through the light incident surface 43. As shown in FIG. 4, most of the light incident on the light guide plate 40 is reflected on the light output surface 41 and the back surface 42 of the light guide plate 40, particularly due to a difference in refractive index between the material forming the light guide plate 40 and air. The total reflection is repeated, and the light guide direction connecting the light incident surface 43 and the opposite surface 44 of the light guide plate 40, particularly in the illustrated example, proceeds in the first direction d1.

  However, the rear surface 42 of the illustrated light guide plate 40 is configured by the unit optical element 47 and has a reflective surface 42 a that is inclined so as to approach the light exit surface 41 as it goes from the light incident surface 43 to the opposite surface 44. doing. The reflection surface 42a is connected via a connection surface 42b. The connection surface 42b extends in the normal direction nd of the light guide plate 40 as an example. Therefore, most of the light traveling in the light guide plate 40 from the light incident surface 43 side to the opposite surface 44 side is reflected by the reflection surface 42a without entering the connection surface 42b of the back surface 42. Become. For this reason, as shown in FIGS. 8 and 9, when light travels through the light guide plate 40 while repeatedly reflecting on the light exit surface 41 and the back surface 42, the incident angle of the light on the light exit surface 41 and the back surface 42 is It gradually decreases and becomes less than the critical angle for total reflection. As a result, the light traveling in the light guide plate 40 is emitted from the light exit surface 41 little by little. According to such a method, by adjusting the distribution of the connection surface 42b, the light amount distribution along the light guide direction of light emitted from the light output surface 41 of the light guide plate 40, in this example, along the first direction d1. It is possible to control the light amount distribution, for example, to uniformize the light amount distribution along the first direction d1.

  As described above, the emission angle of the light emitted from the light guide plate 40 has traveled mainly in the first direction d1 in the light guide plate 40 until then, in a plane parallel to the first direction d1, The light output plate 40 has a relatively large emission angle that is relatively large from the normal direction nd of the light guide plate 40. Specifically, the emission angle of the first direction component of the light emitted from the light guide plate 40, that is, the angle formed by the first direction component of the emitted light and the normal direction nd of the light guide plate 40 is a relatively large angle. There is a tendency to be biased within a narrow angular range. For example, as already described, in the light guide plate having the above-described exemplary shape and size, 65 ° to 80 ° (and 65 ° to 75 ° with respect to the normal direction nd to the plate surface of the light guide plate 40). It can be set so that the peak luminance is generated within a range inclined by an angle of

  The light finally emitted from the light guide plate 40 as described above enters the optical sheets 50 and 60 disposed at the position facing the light output surface 41 of the light guide plate 40 as shown in FIGS. . In the present embodiment, among the regions facing the light exit surface 41 of the light guide plate 40, the first optical sheet 50 is in the first region A1 which is one side in the second direction d2 by dividing the region into two equal parts. Has been placed. Moreover, the 2nd optical sheet 60 is arrange | positioned in 2nd area | region A2 used as the other side in the 2nd direction d2 by equally dividing the said area | region among the area | regions which face the light emission surface 41 of the light-guide plate 40. FIG. . Therefore, approximately half of the light emitted from the light guide plate 40 is incident on the first optical sheet 50 and the remaining approximately half is incident on the second optical sheet 60.

  However, as described above, both the first optical sheet 50 and the second optical sheet 60 are arranged such that the prism surfaces 50a and 60a face the light guide plate 40 side. The prism surfaces 50a and 60a are formed by the surfaces 55a, 55b, 60a and 60b of the unit prisms 55 and 65 having a triangular cross section whose apex angle protrudes toward the light guide plate 40 side. As a result, the light incident on the first optical sheet 50 and the second optical sheet 60 exhibits a deflection function by the same mechanism from the prism surfaces 50a and 60a of the optical sheets 50 and 60, as will be described below.

  As is well shown in FIG. 7, the longitudinal direction of the unit prisms 55 and 65 intersects the first direction d1 that is the direction of light guide by the light guide plate 40, particularly the first direction d1 in the present embodiment. It is parallel to the orthogonal second direction d2. Further, due to the refractive index difference between the material forming the light guide plate 40 and air, the emission angle of the first direction component of the light emitted from the light exit surface 41 of the light guide plate 40, that is, the first direction component of the emitted light and the light guide plate The angle formed by the normal direction nd to the plate surface of 40 tends to be biased within a specific angle range (for example, 65 ° to 85 °). Accordingly, as shown in FIGS. 8 and 9, most of the light emitted from the light exit surface 41 of the light guide plate 40 is transmitted through the first surfaces 55 a and 65 a of the unit prisms 55 and 65 of the optical sheets 50 and 60. Then, the optical sheets 55 and 65 can be designed so as to be incident on the unit prisms 50 and 65 and then totally reflected by the second surfaces 55 b and 65 b of the unit prisms 55 and 65. Due to the total reflection at the second surfaces 55b and 65b of the unit prisms 55 and 65, the light emission characteristics by the light emitted from the light emitting surface 20a of the surface light emitting device 20, more specifically, the light emitting surface 20a of the surface light emitting device 20 It becomes possible to adjust the angular distribution of luminance to a desired profile.

  In the illustrated embodiment, as shown in FIGS. 8 and 9, the angle θa formed by the second surface 55b of the unit prism 55 of the first optical sheet 50 with respect to the first direction d1 is the second optical sheet 60. The second surface 65b of the unit prism 65 is larger than an angle θa formed with respect to the first direction d1. And in the 1st optical sheet 50 in which inclination-angle (theta) a of the 2nd surface 55b is large as shown in FIG. 8, the advancing direction of the light from the light-guide plate 40 is bent largely. As a result, in the plane parallel to both the first direction d1 and the normal direction nd of the light guide plate 40, the traveling direction of the light emitted from the first optical sheet 50 is mainly the first direction with respect to the normal direction nd. It tilts to one side in the direction d1, that is, the side approaching the light source 40. On the other hand, as shown in FIG. 9, in the second optical sheet 60 in which the inclination angle θa of the second surface 55b is relatively small, the traveling direction of light from the light guide plate 40 is not greatly bent. As a result, in the plane parallel to both the first direction d1 and the normal direction nd of the light guide plate 40, the traveling direction of the light emitted from the second optical sheet 60 is mainly the same as the light emitted from the light guide plate 40. Furthermore, it is inclined with respect to the normal direction nd to the other side in the first direction d1, that is, the side away from the light source 30.

  The light that has been deflected by the optical sheets 50 and 60 then passes through the light-emitting surface 20a of the surface light-emitting device 20 formed by the surface film 38 via the diffusion plate 34, the reinforcing plate 37, and the surface film 38. The light is emitted from the surface light emitting device 20 as illumination light. At this time, the diffusing plate 34 is not expected to deform the profile of the luminance angle distribution adjusted by the optical sheets 50 and 60, and is expected to have a diffusing function that gently smoothes minute irregularities on the profile. Has been. Accordingly, the light emission characteristics in the first area A1 facing the first optical sheet 50 are determined exclusively depending on the deflection function in the first optical sheet 50, and the second area facing the second optical sheet 60 is determined. The light emission characteristics in A2 are determined solely depending on the deflection function of the second optical sheet 60. As a result, as described above, the direction (optical axis) pd1 exhibiting the highest luminance in the luminance angle distribution (luminance direction distribution) measured on the light emitting surface 20a in the first region A1, and the second region A2 It is possible to make the direction (optical axis) pd2 exhibiting the highest luminance in the luminance angle distribution (luminance direction distribution) measured on the inner light emitting surface 20a non-parallel.

  Moreover, in the display apparatus 10 shown in FIGS. 1, 4 and 5 to which the surface light emitting device 20 shown in FIGS. 8 and 9 is applied, as a result, the first direction d1 and the normal direction of the light guide plate 40 are obtained. In a plane parallel to both nd, the direction pd1 in which the illumination light from the light emitting surface 20a located in the first region A1 exhibits the highest luminance and the illumination light from the light emitting surface 20a located in the second region A2 The direction pd2 indicating the highest luminance is inclined to the opposite side with respect to the normal direction nd of the light guide plate 40. More specifically, as shown in FIG. 5, the illumination light from the light emitting surface 20a located in the second region A2 is from the back side of the shelf board 15, that is, the main frame 17 side in the first direction d1. , Go to the near side, that is, the side of the person who is observing. On the other hand, as shown in FIG. 4, the illumination light from the light emitting surface 20a located in the first region A1 travels from the near side to the far side of the shelf board 15 in the first direction d1.

  In the example shown in FIG. 5, the villain figure fa is displayed on the shelf board 16 facing the second area A2 of the display device 10. The villain figure fa is illuminated from the back side, and its silhouette is displayed more strongly than the villain figure fa. As a result, the villain figure fa is observed more eerily than the atmosphere created from its creation. On the other hand, in the example shown in FIG. 4, a hero role figure fb is displayed on the shelf board 16 facing the first area A1 of the display device 10. The hero role figure fb is illuminated from the front side thereof, and the face structure is clearly visually recognized. The illuminating light from the surface light emitting device 20 can produce the brilliant atmosphere of the hero role figure fb. In particular, in such a state that the two objects to be illuminated fa and fb are arranged so as to be adjacent to each other on the same shelf plate 16, this is not caused by the surface light from the surface light emitting device 20 instead of the spotlight. Since it is possible to realize lighting with excellent design properties, there is also an unexpectedness and it is possible to create an eye-catching effect that is not found in the past.

  As described above, according to the present embodiment, the first and second optical sheets 50 and 60 having different shapes of the prism surfaces 50a and 60a are arranged at the position facing the light guide plate 40, and the first optical The direction pd1 in which the light transmitted through the sheet 50 exhibits the maximum luminance is different from the direction pd2 in which the light transmitted through the second optical sheet 60 exhibits the maximum luminance. According to such a surface light emitting device 20, it is possible to achieve an excellent eye catching effect, that is, an effect of attracting the eyes of the observer. As a result, it is possible to increase the value of the illuminated object illuminated by the surface light emitting device 20, for example, to stimulate purchase intention for the illuminated object or to improve the aesthetic evaluation of the illuminated object.

  Note that various modifications can be made to the above-described embodiment. Hereinafter, an example of modification will be described with reference to the drawings. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted.

  In embodiment mentioned above, although the surface emitting device 20 showed the example which has the some optical sheet 50 and 60 from which the shape of prism surface 50a, 60a differs, it is not restricted to this. As already described, the surface light-emitting device 20 may include a plurality of optical sheets having different directions in which the prism surface faces. Also in such a modification, the same effect as the above-described embodiment can be obtained. That is, even in such an example, the direction in which the light transmitted through one optical sheet exhibits the highest luminance can be different from the direction in which the light transmitted through the other optical sheet exhibits the highest luminance, An excellent eye-catching effect, that is, an effect that attracts the eyes of the observer can be achieved.

  Here, FIG. 10 shows the surface light emitting device 20 including the third optical sheet 70. The third optical sheet 70 includes a prism surface 70 a formed by the unit prism 75, and exhibits a deflection function with respect to light emitted from the light exit surface 41 of the light guide plate 40. Similar to the first optical sheet 50 and the second optical sheet 60, the third optical sheet 70 includes a sheet-like main body 72 and a large number of unit prisms provided on the main body 72 and arranged in the first direction d1. 75. The unit prism 75 has a first surface 75a located on one side in the first direction d1, that is, a side close to 30, and a second surface 75b located on the other side in the first direction d1. Yes. The prism surface 70a of the third optical sheet 70 is formed by the first surface 75a and the second surface 75b of the unit prism 75. However, the third optical sheet 70 is disposed at a position facing the light guide plate 40 so that the prism surface 70 a faces the opposite side of the light guide plate 40. That is, the third optical sheet 70 is different from the first optical sheet 50 and the second optical element 60 in the direction in which the prism surface faces. As described above, the light emitted from the light guide plate 40 is influenced greatly by the light guide direction so far, and is largely inclined from the normal direction nd to the other side in the first direction d1. Therefore, as shown in FIG. 10, most of the light from the light guide plate 40 is incident not on the first surface 75a but on the second surface 75b inclined in the opposite direction with the traveling direction of the light and the normal direction nd as the center. Tend to occur. The deflecting function of the third optical sheet 70 is exhibited mainly by refraction at the second surface 75b.

  As described above, the first optical sheet 50 and the second optical sheet 60 are different from each other in the direction in which the first optical sheet 50 and the second optical sheet 60 are directed to the prism surface 70a. The deflection function is exerted by a different mechanism. As a result, the direction pd3 in which the light transmitted through the third optical sheet 70 exhibits the maximum luminance is different from the directions pd1 and pd2 in which the light transmitted through the first optical sheet 50 or the second optical sheet 60 exhibits the maximum luminance. can do. Actually, the third optical sheet 70 has the same shape as the first optical sheet 50, and only the direction supported by the support means 25 is changed. In other words, the third optical sheet 70 is supported by turning the first optical sheet 50 upside down. The light transmitted through the third optical sheet 70 shown in the figure is generally deflected in a direction centered on the normal direction nd of the light guide plate 40. From this, it is understood that even when the surface light emitting device 20 has a plurality of optical sheets with different orientations of the prism surface, the same effects as those of the above-described embodiment can be ensured.

  Moreover, the support means 25 may be configured to removably support the optical sheet. According to such an example, for example, the support positions of the first optical sheet 50 and the second optical sheet 60 in the above-described embodiment can be changed. Also, two appropriate optical sheets can be selected from the first to third optical sheets 50, 60, 70 described above according to the light emission characteristics desired for the surface light emitting device 20 and used. Furthermore, if the support means 25 can support the optical sheet with the opposite sides, the light emission characteristics of the surface light emitting device 20 can be further adjusted with a high degree of freedom.

  In the above-described embodiment, the example in which the surface light emitting device 20 supports the two optical sheets of the first optical sheet 50 and the second optical sheet 60 has been described. Three or more optical sheets may be included. For example, in the example shown in FIG. 6, the surface light emitting device 20 supports two optical sheets side by side in the first direction d1 and supports three optical sheets side by side in the second direction d2, for a total of six. One optical sheet 80a, 80b, 80c, 80d, 80e, 80f is included. In the example shown in FIG. 6, at least one of the shape of the prism surface and the direction in which the prism surface faces is different between the at least two optical sheets included in the surface light emitting device 20, and thereby, one of the optical sheets If the direction in which the light transmitted through the light beam exhibits the highest luminance and the direction in which the light transmitted through the other optical sheet exhibits the maximum luminance are different, it is possible to ensure the same operational effects as in the above-described embodiment. it can. In FIG. 6, the light guide plate 40 is not shown, unlike FIG. 3.

  Furthermore, in the above-described embodiment, the example in which the plurality of optical sheets included in the surface light emitting device 20 are completely formed as separate bodies has been described, but the present invention is not limited thereto. For example, a first prism surface is formed in a predetermined region on a single sheet-like main body, and the second prism is different in shape or direction from the first prism surface in another region of the main body. Even in the case where the prism surface is formed, the same operational effects as those of the above-described embodiment can be ensured. In such an example, a planar area in which the first prism surface of the single sheet-like member is formed is treated as the first optical sheet, and the second prism of the single sheet-like member is used. The plane area where the surface is formed is treated as the second optical sheet.

  In addition, although the some modification with respect to embodiment mentioned above was demonstrated above, naturally, it is also possible to apply combining several modifications suitably.

DESCRIPTION OF SYMBOLS 10 Exhibition apparatus 15 Shelf board 20 Surface light-emitting device 20a Light emission surface 25 Support means 30 Light source 31 Light-emitting body 40 Light guide plate 41 Light emission surface 43 Light incident surface 50 1st optical sheet 50a Prism surface 52 Main-body part 55 Unit prism 55a 1st surface 55b Second surface 60 Second optical sheet 60a Prism surface 62 Main unit 65 Unit prism 65a First surface 65b Second surface 70 Third optical sheet 70a Prism surface 72 Main unit 75 Unit prism 75a First surface 75b Second surface

Claims (5)

A light guide plate including a pair of main surfaces and a side surface located between the pair of main surfaces;
A light source disposed facing the side surface of the light guide plate located on one side in the first direction;
A first optical sheet disposed to face one main surface of the light guide plate and including a prism surface;
A second optical sheet having a prism surface, which is disposed to face one main surface of the light guide plate at a position shifted from the first optical sheet along the plate surface of the light guide plate,
The first optical sheet and the second optical sheet differ in at least one of the shape of the prism surface and the direction in which the prism surface faces, so that the light transmitted through the first optical sheet is the highest. The surface emitting device in which the direction in which the luminance is exhibited is different from the direction in which the light transmitted through the second optical sheet exhibits the maximum luminance. The first optical sheet is a plurality of unit prisms arranged in the first direction to form the prism surface, each of the first surfaces being located on one side in the first direction; A plurality of unit prisms having a second surface located on the other side opposite to the one side in one direction,
The second optical sheet is a plurality of unit prisms arranged in the first direction to form the prism surface, each of the first surfaces being located on the one side in the first direction; A plurality of unit prisms having a second surface located on the other side in the first direction,
The surface emitting device according to claim 1, wherein the inclination of the second surface is different between the unit prism of the first optical sheet and the unit prism of the second optical sheet. The prism surface of the first optical sheet faces the light guide plate,
The surface light-emitting device according to claim 1, wherein the prism surface of the second optical sheet faces the light guide plate. Support means for removably supporting the first optical sheet and the second optical sheet;
A third optical sheet having a prism surface having a shape different from both the prism surface of the first optical sheet and the prism surface of the second optical sheet;
The said support means is replaced with at least one of the said 1st optical sheet and the said 2nd optical sheet, It is comprised so that it can support the said 3rd optical sheet, It is any one of Claims 1-3 comprised. Surface light emitting device.   An exhibition apparatus comprising the surface light-emitting device according to claim 1.

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