JP2014222614A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system suitable not only for ordinary interior lighting but also for lighting in a wall-adjacent area.SOLUTION: The lighting system is provided with a lighting device 10 attached to a ceiling 90 connected to a wall 91. The lighting device includes a first light source 21 and a second light source 22 placed facing to each other in a first direction d1. An optical axis od1 due to light emitted from the first light source of illumination light from the lighting device faces to a position on the wall 91. An optical axis od2 due to light emitted from the second light source 22 of illumination light from the lighting device faces to a position shifted from the wall 91. Output of the light emitted from the first light source 21 can be controlled independently from output of light emitted from the second light source 22.

Description

  The present invention provides a lighting system including a lighting device.

  Usually, a lighting device is provided in the room. Various articles such as decorations such as paintings, a so-called whiteboard or writing board called a blackboard, a screen on which image light is projected from a projector, and the like are arranged on or near the indoor wall. When these articles are observed or used, there are cases where it is preferable that the article is illuminated and vice versa. Therefore, conventionally, for example, a spotlight or the like that can independently control the light emission amount may be provided separately from an illumination device that merely increases the room illuminance as shown in Patent Document 1, for example.

JP-A-6-160642

  However, it is not preferable in terms of cost to install a spotlight separately from a normal lighting device. In addition, providing a spotlight separately from the lighting device may not be preferable in terms of indoor aesthetics. The present invention has been made in consideration of such points, and an object thereof is to provide an illumination system suitable not only for normal indoor lighting but also for lighting in the vicinity of a wall.

The lighting system according to the present invention comprises:
With a lighting device attached to the ceiling that connects to the wall,
The lighting device includes a first light source and a second light source arranged to face each other in a first direction,
An optical axis caused by light emitted from the first light source in the illumination light from the illumination device is directed to a position on the wall, and the second light source in the illumination light from the illumination device. The optical axis resulting from the light emitted from the head is directed to a position displaced from the wall,
The output of light emitted from the first light source can be controlled independently of the output of light emitted from the second light source.

  The illumination system according to the present invention further includes a writing board attached to the wall, and an optical axis caused by light emitted from the first light source of illumination light from the illumination device is used for the writing. You may make it go to the position on a board.

  The lighting system according to the present invention may further include a screen that can be deployed between the wall and the lighting device.

An illumination system according to the present invention comprises:
A prism sheet further comprising: a sheet-like main body portion; and a plurality of unit prisms arranged on the main body portion along the first direction,
The prism sheet is arranged such that a unit prism is positioned on the first light source and the second light source side in the normal direction of the prism sheet,
An optical axis caused by light emitted from the first light source of illumination light from the illumination device on a plane parallel to both the normal direction and the first direction of the prism sheet, and the illumination device The optical axis caused by the light emitted from the second light source in the illumination light from the light source may be inclined opposite to each other with respect to the normal direction.

  In the illumination system according to the present invention, the unit prism may extend linearly in a direction intersecting the first direction.

In the lighting system according to the invention,
The first light source is located on one side in the first direction and emits light from the one side toward the other side opposite to the one side in the first direction,
The second light source is located on the other side in the first direction and emits light from the other side to the one side in the first direction;
Each unit prism has a first surface located on the one side in the first direction, and a second surface located on the other side in the first direction,
In a plane parallel to both the normal direction and the first direction of the prism sheet, the optical axis of the light emitted from the first light source is directed to a position on the prism sheet, and the optical axis The light traveling in the parallel direction is reflected by the second surface after entering the unit prism, and travels in a direction inclined to the one side in the first direction from the normal direction of the prism sheet,
In a plane parallel to both the normal direction and the first direction of the prism sheet, the optical axis of the light emitted from the second light source is directed to a position on the prism sheet, and the optical axis Light traveling in a parallel direction may be incident on the unit prism, reflected by the first surface, and traveled in a direction inclined from the normal direction of the prism sheet to the other side in the first direction.

The illumination system according to the present invention further comprises a light guide plate disposed facing the surface of the prism sheet on which the unit prism is formed,
The first light source is disposed to face a side surface of a light guide plate located on one side in the first direction, and is directed from the one side to the other side opposite to the one side in the first direction. Emit light,
The second light source is disposed to face a side surface of the light guide plate located on the other side in the first direction, emits light so as to go from the other side to the one side in the first direction,
Each unit prism has a first surface located on the one side in the first direction, and a second surface located on the other side in the first direction,
When the angular distribution of luminance in a plane parallel to both the normal direction and the first direction of the prism sheet is measured on the light exit surface of the light guide plate facing the prism sheet, the first light source Light that travels from the output surface of the light guide plate in a direction parallel to the direction that provides the highest luminance in the angular distribution of the luminance on the light output surface of the light guide plate due to the light emitted from the light enters the unit prism. And then reflected by the second surface, and proceeds from the normal direction of the prism sheet to the direction inclined to the one side in the first direction,
When the angular distribution of luminance in a plane parallel to both the normal direction and the first direction of the prism sheet is measured on the light exit surface of the light guide plate facing the prism sheet, the second light source Light that travels from the output surface of the light guide plate in a direction parallel to the direction that provides the highest luminance in the angular distribution of the luminance on the light output surface of the light guide plate due to the light emitted from the light enters the unit prism. Then, the light may be reflected by the first surface and proceed from the normal direction of the prism sheet to the direction inclined to the other side in the first direction.

  In the illumination system according to the present invention, the light guide plate may have a sheet-like base and a plurality of unit optical elements arranged in a direction intersecting the first direction.

  In the illumination system according to the present invention, the unit optical elements may extend linearly in a direction intersecting the arrangement direction.

  In the illumination system according to the present invention, the unit optical element may be provided on the prism sheet side of the base, or may be provided on the opposite side of the base from the prism sheet.

  In the illumination system according to the present invention, the base portion may include a main portion made of resin and a diffusion component dispersed in the main portion.

  According to the present invention, it is possible not only to illuminate both the room and the vicinity of the wall by a single lighting device, but also to stop the wall lighting and perform only the room lighting. Therefore, it is possible to eliminate the necessity of installing a spotlight dedicated to the wall, which is advantageous in terms of cost and indoor aesthetics.

FIG. 1 is a diagram for explaining an embodiment according to the present invention, and schematically shows an illumination system. FIG. 2 is a vertical cross-sectional view showing a lighting device included in the lighting system of FIG. FIG. 3 is a perspective view showing a part of the illumination device of FIG. FIG. 4 is a graph showing the angular distribution of luminance on the light emitting surface of the illumination device of FIG. FIG. 5 is a diagram corresponding to FIG. 2 for explaining a modification of the prism sheet. FIG. 6 is a diagram corresponding to FIG. 2 and is a diagram for explaining a modification of the lighting device. FIG. 7 is a diagram corresponding to FIG. 2 and is a diagram for explaining another modified example of the illumination device. FIG. 8 is a perspective view showing an example of a light guide plate that can be incorporated in the illumination device of FIG. 6 or FIG. FIG. 9 is a perspective view showing the light guide plate of FIG. 8 from the opposite side.

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

  In this specification, the terms “sheet”, “plate”, and “film” are not distinguished from each other based only on the difference in designation. For example, “sheet” is a concept that includes members that can be called plates and films. Therefore, for example, “prism sheet” is distinguished from members called “prism plates” and “prism films” only by the difference in names. Can't be done.

  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, the light emitting surface of the illumination device and the sheet surface of a prism sheet 30 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.

  1 to 4 are diagrams for explaining an embodiment of the present invention. Among these, FIG. 1 is a schematic diagram showing the illumination system 5 so that the installation state of the illumination device 10 can be understood. FIG. 2 is a diagram for explaining the operation of the illumination device 10. FIG. 3 is a diagram for explaining the prism sheet 30 and the light source 21 of the illumination device 10. FIG. 4 is a graph showing the light emission characteristics of the illumination device 10.

  The illumination system 5 in the present embodiment includes a plurality of illumination devices 10 and 11 attached to a ceiling 90 connected to a wall 91, a writing board 92 attached to the wall 91, and the illumination device 10 and the writing board 92. And a deployable screen 93. The illumination device 10 has a light emitting surface 10a and emits light in a planar shape from the light emitting surface 10a. The writing board 92 can write and display information and the like like a so-called white board or blackboard. The screen 93 is irradiated with image light from a projector such as a projector, and can display an image. The screen 93 can be stored in a box 94 fixed to the ceiling 90 in a wound state when not used. In the illustrated embodiment, the screen 93 drawn out from the box 94 is disposed at a position facing the writing board 92, and the writing board 92 is covered with the screen 93.

  In addition, it becomes possible for the illuminating device 10 arrange | positioned in proximity to the wall 91 among several illuminating devices 10 and 11 to implement | achieve the illumination with the suitable light distribution characteristic according to the arrangement | positioning position. ing. On the other hand, the illumination devices 11 other than the illumination device 10 arranged in the vicinity of the wall 91 may perform illumination with the same light distribution characteristics as in the past. The present invention is configured in the same manner as the lighting device 10 arranged close to each other and has the same light distribution characteristics. In the following, the configuration, action, optical characteristics, light distribution characteristics, and the like of the lighting device 10 arranged close to the wall 91 will be described in association with the arrangement position.

  As shown in FIG. 2, the illuminating device 10 has the 1st light source 21 and the 2nd light source 22 which are arrange | positioned facing the 1st direction d1. In addition, the illuminating device 10 is arrange | positioned in the position spaced apart from the wall 91 along the 1st direction d1. The lighting device 10, the screen 93 (box 94), the writing board 92, and the wall 91 are arranged in this order in the first direction d1.

  As shown in FIG. 1, the optical axis od <b> 1 resulting from the light emitted from the first light source 21 among the illumination light from the illumination device 10 is directed from the light emitting surface 10 a of the illumination device 10 to a position on the wall 91. Yes. In particular, in the present embodiment, the optical axis od1 is directed to a position of the wall 91 that is covered by the writing board 92 attached to the wall 91. Therefore, it can be said that the optical axis od <b> 1 resulting from the light emitted from the first light source 21 in the illumination light from the illumination device 10 is directed to a position on the writing board 92 attached to the wall 91. On the other hand, the optical axis od <b> 1 resulting from the light emitted from the second light source 22 in the illumination light from the illumination device 10 is directed to a position shifted from the wall 91. In other words, the optical axis od1 is directed to a position other than the wall 91.

  In particular, in the present embodiment, a surface parallel to both the normal direction nd and the first direction d1 of the light emitting surface 10a, that is, the first light source 21 of the illumination light from the illumination device 10 in FIGS. The optical axis od1 caused by the light emitted from the illumination device 10 and the optical axis od1 caused by the light emitted from the second light source 22 among the illumination light from the illumination device 10 are mutually from the normal direction nd of the light emitting surface 10a. Inclined to the opposite side. In the present embodiment, the normal direction nd of the light emitting surface 10a is parallel to the normal direction nd of the sheet surface of the prism sheet 30 described later, is also parallel to the normal direction to the ceiling 90, and It is parallel to the vertical direction.

  On the other hand, about the illuminating device 11 arrange | positioned largely apart from the wall 91 along the 1st direction d1, similarly to the illuminating device 10, it is the light from the 1st light source 21 regarding the normal direction nd of the light emission surface 10a. The resulting optical axis od1 of the illumination light and the optical axis od1 of the illumination light of the illuminating device 11 caused by the light from the second light source 22 are inclined to the opposite side. However, since the illuminating device 11 is arranged far away from the wall 91 along the first direction d1, the optical axis od1 of the illuminating light of the illuminating device 11 resulting from the light from the first light source 21 is Similar to the optical axis od <b> 2 of the illumination light of the illumination device 11 caused by the light from the two light sources 22, it is directed to a position shifted from the wall 91.

  In the present specification, the optical axis means a direction in which the maximum luminance is obtained in the luminance distribution in each direction due to the target light (light beam).

  Next, a configuration example of the lighting device 10 that can realize the light distribution characteristics described above will be specifically described.

  As shown in FIGS. 1 and 2, the illumination device 10 includes a prism sheet 30 that receives light from the first light source 21 and the second light source 22. The prism sheet 30 has a light incident side surface 30b that receives light from the first light source 21 and the second light source 22, and a light output side surface 30a facing the indoor side (that is, the illuminated region side). Moreover, the illuminating device 10 includes a case 15 provided so as to face the light incident side surface 30 b of the prism sheet 30. The case 15 covers the light incident side surface 30b of the prism sheet 30 so as to be connected to the entire circumference of the side end surface of the prism sheet 30 at the end thereof. The inner surface of the case 15 is formed as a reflective surface made of a highly reflective material such as metal.

  In the illustrated example, the prism sheet 30 is configured to have a quadrangular shape in plan view, and is opposed to the pair of edge portions 30c1 and 30c2 facing the first direction d1 and the second direction d1. And another pair of edges. As shown in FIG. 3, in the illustrated example, the first direction d1 and the second direction d1 are orthogonal to each other.

  As shown in FIG. 2, the first light source 21 is provided in the vicinity of the edge portion 30c1 located on one side in the first direction d1 of the pair of edge portions facing the first direction d1 of the prism sheet 30, The 2nd light source 22 is provided in the vicinity of the edge part 30c2 located in the other side in the 1st direction d1 among the pair of edge parts which oppose the 1st direction d1 of the prism sheet 30. FIG. The first light source 21 projects light from one side to the other side in the first direction d1, and the second light source 22 projects light from the other side to the one side in the first direction d1. To do.

  Each of the light sources 21 and 22 has a single light emitting member 25 or a plurality of light emitting members 25 forming a group. As the light emitting member 25 constituting the light sources 21 and 22, various known light emitting members 25, for example, a cold cathode tube, in particular, a cold cathode tube with a narrow light distribution direction can be used. However, in the illustrated example, each of the light sources 21 and 22 is configured using a plurality of point light emitting members 25, typically a plurality of light emitting diodes (LEDs) arranged in a line. A large number of light emitting members 25 constituting the light sources 21 and 22 are arranged side by side along the longitudinal direction of the corresponding edge portions 30c1 and 30c2. That is, as shown in FIG. 3, in the present embodiment, a large number of point light emitting members 25 forming the light sources 21 and 22 are arranged side by side in the second direction d2.

  As well shown in FIGS. 2 and 3, in the illumination device 10, the light emitting member 25 that constitutes the light sources 21 and 22 extends outward of the outer contour of the prism sheet 30 along the sheet surface of the prism sheet 30. positioned. More specifically, the light emitting members 25 of the pair of light sources 21 and 22 are respectively disposed at positions on both outer sides of the pair of edge portions 30c1 and 30c2 facing the first direction d1. That is, in plan view (when observed from the normal direction nd to the prism sheet 30), the light emitting members 25 that constitute the light sources 21 and 22 are arranged at positions that do not overlap the prism sheet 30.

  Moreover, in this illuminating device 10, as shown in FIG. 2, the light emitting member 25 which comprises the light sources 21 and 22 is arrange | positioned in the position shifted | deviated from the prism sheet 30 along the front direction nd. More specifically, the light emitting member 25 that constitutes the light sources 21 and 22 is on the side away from the prism sheet 30 along the normal direction nd to the sheet surface of the prism sheet 30 rather than the light incident side surface 30b of the prism sheet 30. It is arranged at a position shifted to the side away from the room. For this reason, as shown in FIG. 2, light having directivity emitted by the light emitting member 25 constituting the light sources 21 and 22 can directly enter the light incident side surface 30 b of the prism sheet 30.

  Incidentally, in the illustrated example, the light emitting member 25 includes a point-like light emitter 26 such as an LED, and a cap 27 provided so as to cover the light emitter 26. The cap 27 controls the traveling direction of light emitted from the light emitter 26 and adjusts the light distribution characteristics of the light emitting member 25. That is, the light emitting member 25 emits light with directivity rather than emitting light radially with a uniform luminous intensity. The light emitting member 25 emits light with a different luminous intensity (unit: candela) in each direction, and has a peak luminous intensity in a specific direction pd. As the inclination angle with respect to the specific direction pd increases, the value of the luminous intensity gradually decreases. Preferably, the arrangement of the light emitting members 25 constituting the light sources 21 and 22 is determined in consideration of such directivity characteristics (light distribution characteristics, in other words, luminous intensity angle (direction) distribution). Note that the specific direction that provides the peak luminous intensity is the optical axes pd1 and pd2 of the light emitted from the light sources 21 and 22.

  As shown in FIG. 2, the light is emitted from each of the first light sources 21 and 22 on a surface parallel to both the normal direction nd of the prism sheet 30 (that is, the normal direction nd of the light emitting surface 10a) and the first direction d1. The optical axes pd1 and pd2 of the light to be inclined are inclined from the direction parallel to the sheet surface of the prism sheet 30 and are directed to the prism sheet 30 side. Further, the light emitting member 25 is arranged so that the optical axes pd1 and pd2 are directed to the position on the light incident side surface 30b of the prism sheet 30. As a result, at least a part of the light emitted from each light emitting member 25 can directly enter the prism sheet 30, that is, can enter the prism sheet 30 without passing through another member.

  According to such setting of the optical axes pd1 and pd2, the light emitted from the light emitter 26 of the light emitting member 25 can be used very efficiently. From the viewpoint of improving the utilization efficiency of light from the light sources 21 and 22, as shown in the illustrated example, surfaces along both the normal direction nd and the first direction d1 to the prism sheet 30 ( 2), the arrangement (position) of the light emitting member 25 is arranged so that light is emitted at the maximum luminous intensity toward a position that is intermediate between the pair of edge portions 30c1 and 30c2 of the prism sheet 30 or a region that is in the vicinity of the position. , Orientation) is preferably adjusted.

  In the illumination system 5 described here, the output of light emitted from the first light source 21 can be controlled independently of the output of light emitted from the second light source 22. In particular, in the present embodiment, the output of light emitted from the second light source 22 can also be controlled independently of the output of light emitted from the first light source 21. The outputs of the first light source 21 and the second light source 22 may be controlled so that the amount of emitted light or the emitted light intensity can be adjusted independently of each other, or only the presence or absence of emission is controlled independently of each other. It may be possible. In the present embodiment, as shown in FIG. 1, the illumination system 5 includes a control unit 18, and the control unit 18 is capable of continuously adjusting the amount of light emitted from the first light source 21. The switch 18a and the second switch 18b capable of continuously adjusting the amount of light emitted from the second light source 22 are provided. By operating the control means 18, the outputs of the first light source 21 and the second light source 22 can be controlled independently of each other.

  Next, the prism sheet 30 will be described.

  The prism sheet 30 described here has a light control function of changing the traveling direction of light. As a specific configuration, as shown in FIGS. 2 and 3, the light incident side surface 30 b of the prism sheet 30 is a prism surface formed by a large number of unit prisms (unit prisms) 40 arranged side by side. Optical element surface). By this prism surface, the prism sheet 30 has a function of correcting the traveling direction of light, and in particular, in the illustrated example, deflects the traveling direction of the light so as to reduce the angle formed by the traveling direction of the light with respect to the front direction nd. Deviation function is developed.

  The “unit prism” in the present specification refers to an element having a function of changing the traveling direction of the light by exerting an optical action such as refraction or reflection on the light, and the “unit shape element”. The “unit optical element” and the “unit lens” are not distinguished from each other only based on the difference in names. Similarly, “prism”, “lens” and “optical element” are not distinguished from each other based solely on the difference in designation.

  As well shown in FIG. 3, the prism sheet 30 includes a sheet-like main body 35 and a large number of unit prisms 40 arranged in the first direction d1 on the light incident side 35b of the main body 35. And have. Each unit prism 40 extends in a direction intersecting the first direction d1 and parallel to the sheet surface of the prism sheet 30. In the illustrated example, each unit prism 40 extends linearly in a second direction d1 orthogonal to the first direction d1. Further, the unit prisms 40 included in the prism sheet 30 are configured identically. Further, the unit prisms 40 are arranged without a gap, and as a result, the light incident side surface 30 b of the prism sheet 30 is formed by the unit prisms 40. The prism sheet 30 is arranged so that the sheet surface thereof is parallel to the first direction d1, and in particular in the illustrated example, the prism sheet 30 extends in the horizontal direction parallel to the ceiling 90.

  The cross section shown in FIG. 2 is a cross section along both the arrangement direction d1 of the unit prisms 40 and the normal direction to the sheet surface of the prism sheet 30 (hereinafter, also simply referred to as “main cut surface”). As shown in FIG. 2, each unit prism 40 has a triangular shape on the main cutting plane. Accordingly, the first surface 41 and the second surface 42 of the unit prism 40 are each formed as a flat surface. In particular, in the illustrated example, the cross-sectional shape of the main cutting surface of the unit prism 40 is an isosceles triangular shape arranged symmetrically about the normal direction nd to the sheet surface of the prism sheet 30. According to the prism sheet 30 having such a unit prism 40, a symmetrical optical function can be exhibited with respect to the light from the first light source 21 and the light from the second light source 22. As a result, symmetrical light distribution characteristics can be exhibited with the normal direction nd of the prism sheet 30 as the center. That is, on the surface parallel to both the normal direction nd and the first direction d1 to the light emitting surface 10a, the optical axis od1 caused by the light emitted from the first light source 21 of the illumination light from the illumination device 10 and The optical axis od2 resulting from the light emitted from the second light source 22 in the illumination light from the illumination device 10 is symmetric about the normal direction nd to the light emitting surface 10a.

  The thickness t (see FIG. 2) of the prism sheet 30 having the above configuration is assumed to be up to the first decimal place rounded to the second decimal place, assuming that the size of the prism sheet 30 is 600 mm × 600 mm. The numerical value is preferably 0.3 mm or more, and more preferably 0.5 mm or more. Here, the thickness t of the prism sheet 30 is the length along the normal direction nd of the prism sheet 30 from the light exit side surface 30a of the prism sheet 30 to the top 40a of the unit prism 40, as shown in FIG. is there. When the prism sheet 30 is thin, the prism sheet 30 is bent by its own weight, particularly in the lighting device 10 attached to the ceiling 90. In this case, since the relative position of the prism sheet 30 with respect to the light sources 21 and 22 is deviated from the design value, it is impossible to realize illumination with desired light distribution characteristics. However, the thickness t of the prism sheet 30 is preferably 5.0 mm or less in order to avoid an unsuitable weight for mounting on the ceiling 90.

  Further, as other dimensions of the prism sheet 30, the width w (in the first direction d1 of the unit prism 40 in the plane of FIG. 2 along both the normal direction nd and the first direction d1 to the prism sheet 30). 2) can be 1 μm or more and 500 μm or less, and the height h (see FIG. 2) of the unit prism 40 along the normal direction nd of the prism sheet 40 can be 0.5 μm or more and 750 μm or less. . Further, the ratio of the height h of the unit prism 40 to the width w of the unit prism 40, that is, the aspect ratio (h / w) of the unit prism 40 can be 0.9 or more and 2.0 or less, and 1.0 It is more preferably 2.0 or more and 2.0 or less, and further preferably 1.0 or more and 1.5 or less. Furthermore, when the cross-sectional shape of the unit prism 40 is a triangular shape or a shape formed by chamfering the apex angle of the triangular shape, the apex angle θa (see FIG. 2) is set to 30 ° to 55 °. It is preferable to set the angle between 40 ° and 55 °.

  As an example, the prism sheet 30 having the above-described configuration can be manufactured by extrusion molding or by molding a unit prism 40 made of an ionizing radiation curable resin on a base material.

  Next, the operation of the illumination device 10 will be described mainly with reference to FIGS. 1 and 2.

  As described above, in the cross section shown in FIG. 2, the optical axes pd1 and pd2 of the light emitted from the light emitting members 25 of the light sources 21 and 22 are directed to positions on the light incident side surface 30b of the prism sheet 30, respectively. It extends. For this reason, much light emitted from the light emitting members 25 of the first light source 21 and the second light source 22 enters the light incident side surface 30b of the prism sheet 30 directly, that is, without entering other members.

  In the illustrated example, a light guide plate for uniformizing the light amount distribution along the irradiation direction (light guide direction) of light from the light sources 21 and 22 is not provided. However, as described above, the optical axes pd1 and pd2 of the light emitted from the light emitting member 25 of the light sources 21 and 22 extend toward the position on the light incident side surface 30b of the prism sheet 30, and the light emitting member 25. The light emission characteristics by can be adjusted by the cap 27, for example. As a result, the light amount distribution along the first direction d1 can be made uniform to such an extent that a sense of incongruity does not occur.

  The light from the light sources 21 and 22 is also emitted in a direction inclined from the optical axes pd1 and pd2 of the light sources 21 and 22. Therefore, a part of the light emitted from the light emitting member 25 of the light sources 21 and 22 can enter the reflecting surface 16 of the case 15 directly, that is, without entering another member. Such light can be incident on the light incident side surface 30 b of the prism sheet 30 after being reflected by the reflecting surface 16.

  The prism sheet 30 has a polarization function expressed by the unit prism 40, and changes the traveling direction of light from the light sources 21 and 2 to a direction within a certain angle range centered on a predetermined direction. As is well shown in FIG. 2, the basic principle of the deflection function by the unit prism 40 having a triangular cross section is that light incident from one surface (incident surface) of the unit prism 40 is converted to the other surface (total reflection). The traveling direction of the light is changed by total reflection on the surface. As shown in FIG. 2, each light emitting member 25 included in the first light source 21 is located on one side in the first direction d1 and irradiates light from one side to the other side in the first direction d1. The light from each light emitting member 25 of the first light source 21 enters the unit prism 40 from the first surface 41 located on one side of the unit prism 40, and the second surface located on the other side of the unit prism 40. Total reflection occurs at 42. On the other hand, each light emitting member 25 included in the second light source 22 is located on the other side in the first direction d1 and irradiates light from the other side to the one side in the first direction d1. Accordingly, light from each light emitting member 25 of the second light source 22 enters the unit prism 40 from the second surface 42 of the unit prism 40 and is totally reflected by the first surface 41 of the unit prism 40.

  Such a deflection function by the unit prism 40 is mainly exerted on a light component parallel to the first direction d1 which is the arrangement direction of the unit prisms 40. Then, by appropriately designing the cross-sectional shape of the unit prism 40, the aspect ratio (height h / width w) of the unit prism 40 is related particularly to the main incident angle of the light source light to the prism sheet 30. By setting, the degree of the deflection function in the unit prism 40 of the prism sheet 30 can be adjusted.

  In the example shown in FIG. 2, the light L21 traveling in the direction parallel to the optical axis pd1 of the light emitted from the first light source 21 on the surface parallel to both the normal direction nd and the first direction d1 of the prism sheet 30. After being incident on the unit prism 40, it is reflected by the second surface 42 of the unit prism 40 and proceeds in a direction inclined to one side in the first direction d1 from the normal direction nd of the prism sheet 30. That is, the light L21 traveling in the direction parallel to the optical axis pd1 of the light emitted from the first light source 21 on the surface parallel to both the normal direction nd and the first direction d1 of the prism sheet 30 is the unit prism 40. Due to the deflection function, the traveling direction is turned back in the first direction d1.

  On the other hand, in the illustrated example, the prism sheet 30 and the light sources 21 and 22 are configured symmetrically about the normal direction nd of the prism sheet 30, so that the optical path of the light emitted from the second light source 22 Are symmetric with respect to the optical path of the light emitted from the first light source 21 and the normal direction nd of the prism sheet 30. That is, as shown in FIG. 2, the light advances from the second light source 22 in the direction parallel to the optical axis pd2 on the plane parallel to both the normal direction nd and the first direction d1 of the prism sheet 30. After entering the unit prism 40, the light L22 is reflected by the first surface 41 of the unit prism 40 and proceeds in a direction inclined from the normal direction nd of the prism sheet 30 to the other side in the first direction d1. . That is, the light L22 traveling in the direction parallel to the optical axis pd2 of the light emitted from the second light source 22 on the surface parallel to both the normal direction nd and the first direction d1 of the prism sheet 30 is the unit prism 40. Due to the deflection function, the traveling direction is turned back in the first direction d1.

  The light deflected by the prism sheet 30 as described above is then emitted from the light emitting surface 10a of the illumination device 10 formed by the light emitting side surface 30a of the prism sheet 30.

  Here, FIG. 4 shows the luminance angle distribution on the light emitting surface 10a measured from each direction on the surface parallel to both the normal direction nd and the first direction d1 of the light emitting surface 10a. As shown in FIG. 4, in the plane parallel to both the normal direction nd and the first direction d1 of the light emitting surface 10a, that is, the first of the illumination lights from the illumination device 10 in FIGS. The optical axis od1 caused by the light emitted from the first light source 21 and the optical axis od1 caused by the light emitted from the second light source 22 among the illumination light from the illumination device 10 are in the normal direction of the light emitting surface 10a. Inclined from nd to the opposite sides. In the present embodiment, the optical axis od1 of the illumination light of the illumination device 10 caused by the light emitted from the first light source 21 and the light of the illumination light of the illumination device 10 caused by the light emitted from the second light source 22 The axis od2 is symmetric with respect to the normal direction nd of the light emitting surface 10a (that is, the normal direction nd of the prism sheet 30).

  Note that the luminance angle distribution shown in FIG. 4 is indicated by a dotted line, and the luminance angle distribution resulting from the light emitted from the first light source 21 of the illumination light is emitted from the second light source 22 of the illumination light. The luminance angle distribution resulting from the emitted light is indicated by a one-dot chain line. In addition, the luminance angle distribution obtained by the total illumination light obtained by adding the light emitted from the first light source 21 and the light emitted from the second light source 22 is indicated by a solid line. In the example shown in FIG. 4, the optical axis od1 caused by the light emitted from the first light source 21 of the illumination light and the optical axis od2 caused by the light emitted from the second light source 22 among the illumination light. Is a direction inclined with respect to the normal direction nd of the light emitting surface 10a, but the optical axis of all illumination light is parallel to the normal direction nd of the light emitting surface 10a. However, the luminance distribution shown in FIG. 4 is merely an example, and for example, the luminance angle distribution of all illumination light shown in practice in FIG. 4 may have two peaks.

  By the way, in the illumination system 5 described here, the above-described illumination device 10 is attached to the ceiling 90 at a position near the wall 91. As described above, the optical axis od1 caused by the light emitted from the first light source 21 among the illumination light from the illumination device 10 is directed from the light emitting surface 10a of the illumination device 10 toward the position on the wall 91. Yes. In particular, in the present embodiment, the optical axis od1 is directed to a position of the wall 91 that is covered by the writing board 92 attached to the wall 91. That is, the optical axis od <b> 1 resulting from the light emitted from the first light source 21 in the illumination light from the illumination device 10 is directed to a position on the writing board 92 attached to the wall 91. A screen 93 is provided between the writing board 92 and the lighting device 10 so as to cover the writing board 92 so as to be developed. On the other hand, the optical axis od <b> 1 resulting from the light emitted from the second light source 22 in the illumination light from the illumination device 10 is directed to a position shifted from the wall 91. In other words, the optical axis od1 is directed to a position other than the wall 91. And the output of the 1st light source 21 of the illuminating device 10 and the output of the 2nd light source 22 are controllable independently.

  In such an illumination system 5, when writing and displaying some information on the writing board 92, the writing board 92 can be illuminated brightly by emitting light from the first light source 21 of the lighting device 10. it can. At this time, light may also be emitted from the second light source 22 of the lighting device 10 to illuminate the person who is writing in the room or the writing board 92, or for writing. In order to emphasize or promote the display of information using the board 92, the output of the second light source 22 of the lighting device 10 may be weakened or stopped. On the other hand, when the screen 93 spreads between the lighting device 10 and the writing board 92 and image light is projected from the projector onto the screen 93, the visibility of the image displayed on the screen 93 should be improved. The emission of light from the first light source 21 of the lighting device 10 may be stopped. At this time, light is also emitted from the second light source 22 of the lighting device 10 to brightly illuminate the room, and the image on the screen 93 can be observed with sufficient contrast while checking the material at hand. it can.

  That is, according to the illumination system 5 described here, the presence / absence of illumination of the wall surface is provided independently of the control of the presence / absence of indoor lighting without providing a lighting device such as a spotlight separately from a normal illumination device. Can be controlled. As a result, it is possible to eliminate the necessity of installing a spotlight dedicated to the wall, which is very preferable from the viewpoints of cost and room harmony or aesthetics. In particular, in the present embodiment, the illumination device 10 that enables illumination in the vicinity of the wall 91 can be configured in the same manner as the other illumination devices 11 included in the illumination system 5 used exclusively for indoor illumination. For this reason, it is more excellent in terms of cost and room harmony or aesthetics. In addition, the output of the first light source 21 and the second light source 22 can be controlled very easily using the control means 18.

  According to the present embodiment as described above, not only lighting of both the room and the vicinity of the wall is performed by the single lighting device 10, but the lighting of the wall 91 is stopped and only the room lighting is performed. Can do. Therefore, it is possible to eliminate the necessity of installing a spotlight dedicated to the wall, which is advantageous in terms of cost and indoor aesthetics.

  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.

  First, as a second embodiment, as shown in FIG. 5, by adjusting the configuration of the prism sheet 30, for example, by adjusting the aspect ratio (height h / width w) of the unit prism 40, The traveling direction of light projected from the first light source 21 or the second light source 22 and transmitted through the prism sheet 30 may not be narrowed down to the normal direction nd of the prism sheet 30. That is, in the example shown in FIG. 5, the surface parallel to both the normal direction nd and the first direction d1 of the prism sheet 30 is parallel to the optical axis pd1 of the light emitted from the first light source 21. The traveling light L51 is incident on the unit prism 40 and then reflected by the second surface 42 of the unit prism 40, but after the reflection, the direction inclined from the normal direction nd of the prism sheet 30 to the other side in the first direction d1. Continue to. The light L52 traveling in the direction parallel to the optical axis pd2 of the light emitted from the second light source 22 on the surface parallel to both the normal direction nd and the first direction d1 of the prism sheet 30 is the unit prism 40. Is reflected by the first surface 41 of the unit prism 40, but continues to travel in a direction inclined to one side in the first direction d1 from the normal direction nd of the prism sheet 30 even after reflection. That is, the light L51 traveling in the direction parallel to the optical axis pd1 of the light emitted from the first light source 21 on the surface parallel to both the normal direction nd and the first direction d1 of the prism sheet 30 is also the second light source 22. None of the light L52 traveling in a direction parallel to the optical axis pd2 of the light emitted from the light beam is bent back in the first direction d1 by the deflection function of the unit prism 40. In the second embodiment shown in FIG. 5, the wall 91 is located on the other side in the first direction d <b> 1 with respect to the lighting device 10. Also by such 2nd Embodiment, there can exist an effect similar to embodiment mentioned above.

  In the second embodiment shown in FIG. 5, for example, the first surface 41 and the second surface with respect to the normal direction nd of the prism sheet 30 are compared with the above-described embodiment shown in FIG. The inclination angle of 42 is increased. For this reason, the light incident on the prism sheet 30 in the vicinity of the light sources 21 and 22 also includes light incident on the prism surfaces 41 and 42 on the unintended side due to the deflection function of the prism sheet 30. As an example, as shown in FIG. 5, the light L53 emitted from the second light source 22 enters the first surface 41 instead of the second surface 42 on the other side in the first direction d1 closest to the wall 91. The first surface 41 is refracted. As a result, the light L53 comes to the wall 91 depending on the inclination angle of the prism surfaces 41 and 42. Further, the amount of incident light on the light incident side surface 30b of the prism sheet 30 tends to increase in the vicinity of the light source. That is, in the second embodiment shown in FIG. 5, the light L53 that illuminates the wall 91 is slightly included in the light from the second light source 22 that is originally intended to illuminate the room. Can be secured. Therefore, in the second embodiment, it is possible to prevent the wall 91 from becoming too dark in a state where the output from the first light source 21 is completely stopped. On the contrary, according to the embodiment of FIG. 2 described above, it is possible to more effectively prevent the light from going to the wall 91 in a state where the output from the first light source 21 is completely stopped.

  Furthermore, as 3rd Embodiment, as shown in FIG. 6, you may make it the illuminating device 10 of embodiment mentioned above further have the light-guide plate 50. As shown in FIG. In 3rd Embodiment, it can comprise similarly to embodiment mentioned above except the illuminating device 10 having the light-guide plate 50. FIG. Further, as a fourth embodiment, as shown in FIG. 7, the above-described lighting device 10 of the second embodiment may further include a light guide plate 50. In the embodiment shown in FIGS. 6 and 7, the light guide plate 50 is disposed to face the light incident surface 30 b on which the unit prism 40 of the prism sheet 30 is formed. In the embodiment shown in FIGS. 6 and 7, the first light source 21 is disposed to face the side surface of the light guide plate 50 located on one side in the first direction d1, and the second light source 22 is It arrange | positions facing the side surface of the light-guide plate 50 located in the other side in the 1st direction d1. The light guide plate 50 shown in FIGS. 6 and 7 has a sheet-like base 55. The base portion 55 has a main portion 56 and a diffusion component 57 dispersed in the main portion 56. The light traveling in the light guide plate 50 is diffused by the diffusing component 57, so that it enters the main surface of the light guide plate 50 at an angle smaller than the total reflection critical angle and is extracted from the light guide plate 50.

  In the third embodiment shown in FIG. 6, as in the above-described embodiment, the angular distribution of luminance in a plane parallel to both the normal direction nd and the first direction d1 of the prism sheet 30. Is measured on the light exit surface 50a facing the prism sheet 30 of the light guide plate 50, the highest brightness is obtained in the luminance angle distribution on the light exit surface 50a of the light guide plate 50 due to the light emitted from the first light source 21. The light L61 that travels from the outgoing surface 50a of the light guide plate 50 in a direction parallel to the direction to be provided is incident on the unit prism 40, then reflected by the second surface 42, and then from the normal direction nd of the prism sheet 30 to the first direction. Proceed in a direction inclined to one side at d1. Further, when the luminance angle distribution in a plane parallel to both the normal direction nd and the first direction d1 of the prism sheet 30 is measured on the light exit surface 50a facing the prism sheet 30 of the light guide plate 50, the first The light L62 that travels from the outgoing surface 50a of the light guide plate 50 in a direction parallel to the direction that provides the highest luminance in the angular distribution of the luminance on the light outgoing surface 50a of the light guide plate 50 caused by the light emitted from the two light sources 22 is After being incident on the unit prism 40, it is reflected by the first surface 41, and proceeds from the normal direction nd of the prism sheet 30 to the direction inclined to the other side in the first direction d1. In the third embodiment shown in FIG. 6, the wall 91 is located on one side in the first direction d <b> 1 with respect to the lighting device 10. Also according to the third embodiment, the same operational effects as those of the above-described embodiment can be obtained.

  On the other hand, in the fourth embodiment shown in FIG. 7, as in the second embodiment described above, in the plane parallel to both the normal direction nd and the first direction d1 of the prism sheet 30. Luminance angle distribution on the light exit surface 50a of the light guide plate 50 caused by the light emitted from the first light source 21 when the angle distribution of the brightness of the light guide plate 50 is measured on the light exit surface 50a facing the prism sheet 30 of the light guide plate 50. The light L71 that travels from the outgoing surface 50a of the light guide plate 50 in a direction parallel to the direction that provides the highest luminance in the distribution is incident on the unit prism 40 and then reflected by the second surface 42. Continue in the direction inclined from the normal direction nd to the other side in the first direction d1. Further, when the luminance angle distribution in a plane parallel to both the normal direction nd and the first direction d1 of the prism sheet 30 is measured on the light exit surface 50a facing the prism sheet 30 of the light guide plate 50, the first The light L72 that travels from the outgoing surface 50a of the light guide plate 50 in a direction parallel to the direction that provides the highest luminance in the angular distribution of the luminance on the light outgoing surface 50a of the light guide plate 50 caused by the light emitted from the two light sources 22 is After being incident on the unit prism 40, the light is reflected by the first surface 41, and continues to travel in the direction inclined to one side in the first direction d 1 from the normal direction nd of the prism sheet 30 even after reflection. In the fourth embodiment shown in FIG. 7, the wall 91 is located on the other side in the first direction d <b> 1 with respect to the lighting device 10. Also according to the fourth embodiment, the same operational effects as those of the above-described embodiment can be obtained.

  The light emitted from the light exit surface 50a of the light guide plate 50 tends to be inclined at a large angle toward the side away from the light source from which the light is emitted with respect to the normal direction to the light guide plate 50 toward the plate surface. . The directivity of the emitted light from the light exit surface 50a of the light guide plate 50 is weak in the vicinity of the light sources 21 and 22 from which the light is emitted in the first direction d1 that is the light guide direction. It will become very strong if it advances to some extent along. Further, in the fourth embodiment shown in FIG. 7, the first surface 41 and the second surface with respect to the normal direction nd of the prism sheet 30 are compared with the third embodiment shown in FIG. 6. The inclination angle of 42 is increased. Furthermore, the amount of light emitted from the light exit surface 50a of the light guide plate 50 tends to increase in the vicinity of the light source along the light guide direction. From the above, light incident on the prism sheet 30 in the vicinity of the light sources 21 and 22 also includes light incident on the prism surfaces 41 and 42 on the unintended side due to the deflection function of the prism sheet 30. As an example, as shown in FIG. 7, the light L73 emitted from the second light source 22 is incident on the first surface 41 instead of the second surface 42 on the other side in the first direction d1 closest to the wall 91. The first surface 41 is refracted. As a result, the light L73 travels toward the wall 91, depending on the inclination angle of the prism surfaces 41 and 42. That is, in the fourth embodiment shown in FIG. 7, the light L73 for illuminating the wall 91 can be secured in the light from the second light source 22 that is originally intended to illuminate the room. . Therefore, in the fourth embodiment, it is possible to prevent the wall 91 from becoming too dark in a state where the output from the first light source 21 is completely stopped. Conversely, according to the third embodiment shown in FIG. 6, it is possible to more effectively prevent the light from traveling toward the wall 91 in a state where the output from the first light source 21 is completely stopped. .

  In the third embodiment and the fourth embodiment, various known light guide plates 50 can be used. For example, as shown in FIGS. 8 and 9, a base 55 and unit optical elements 60 arranged on one surface of the base 55 may be included. The unit optical elements 60 are arranged in a direction intersecting the first direction d1, for example, the second direction d2. Each unit optical element 60 extends linearly in a direction intersecting the arrangement direction, for example, in the first direction d1. Such unit optical element 60 functions as an element that promotes extraction of light from the light guide plate 50 and also functions as an element that controls the optical path of the light component along the arrangement direction. In general, when the unit optical element 60 of the light guide plate 50 faces the light incident side surface 30 b of the prism sheet 30, surfaces along both the arrangement direction of the unit optical elements 60 and the normal direction of the light guide plate 50. Inside, a deflection function that reduces the angle formed by the traveling direction of the outgoing light emitted from the light guide plate 50 toward the prism sheet 30 with respect to the normal direction of the light guide plate 50 is manifested. On the other hand, when the base portion 55 of the light guide plate 50 faces the light incident side surface 30 b of the prism sheet 30, in a plane along both the arrangement direction of the unit optical elements 60 and the normal direction of the light guide plate 50. In addition, a diffusion function for increasing the angle formed by the traveling direction of the outgoing light emitted from the light guide plate 50 toward the prism sheet 30 with respect to the normal direction of the light guide plate 50 is exhibited. Further, in the light guide plate 50 shown in FIGS. 8 and 9, a slope 58 is formed on the other surface of the base portion 55 where the unit optical element 60 is not provided. The inclined surface 58 also functions as an element that promotes extraction of light from the light guide plate 50.

  Next, modified examples applicable to the four embodiments shown in FIGS. 1 to 9 will be further described.

  For example, in the above-described embodiment, the lighting system 5 includes the writing board 92 and the screen 93, but is not limited thereto. For example, the lighting device 10 may be used to illuminate a room and a decoration attached to the wall 91. Further, the output of the first light source 21 may be stopped in order to prevent reflection on the wall 91. Also in such an example, when a situation occurs in which it is not preferable to illuminate the wall 91 while illuminating the room with the illumination device 10 according to environmental conditions such as the incident angle of sunlight, the illumination system 5 Works effectively.

  In the above-described embodiment, the lighting system 5 includes the plurality of lighting devices 10 and 11 and the plurality of lighting devices 10 and 11 are configured to be the same as each other. However, the present invention is not limited thereto. The plurality of lighting devices 10 and 11 may have different configurations.

  Furthermore, in the above-described embodiment, an example of the cross-sectional shape of the main cutting surface of the unit prism 40 of the prism sheet 30 has been described, but the present invention is not limited to the above-described example. For example, although the example in which the cross-sectional shape of the main cutting surface of the unit prism 40 is a triangular shape has been shown, the present invention is not limited to this, and the cross-sectional shape of the main cutting surface of the unit prism 40 can be designed in various shapes. For example, the triangular top portion forming the cross-sectional shape of the unit prism 40 may be chamfered.

  Moreover, although the 1st surface 41 and the 2nd surface 42 of the unit prism 40 showed the example comprised symmetrically centering | focusing on the normal line direction nd of the prism sheet 30, it is not restricted to this. The first surface 41 and the second surface 42 may be asymmetric, and the light from the first light source 21 and the light from the second light source 22 may be deflected in desired directions that are asymmetric with respect to each other.

  Furthermore, on the main cutting surface of the prism sheet, at least one of the two sides extending from the triangular main body 35 described above may be deformed so as to be a curved bulging outward. Furthermore, the unit prism 40 may have a curved outer contour on the main cut surface of the prism sheet 30. That is, the surface of the unit prism 40 may be configured as a curved surface. As an example of a specific shape, the unit prism 40 has a shape corresponding to a part of an ellipse (a semi-ellipse as an example) or a part of a circle (a semi-circle as an example) on the main cut surface of the prism sheet 30. It may be.

  In the above-described embodiment, the example in which the unit prisms 40 included in the prism sheet 30 are formed in the same manner has been described. However, the present invention is not limited to this. For example, the plurality of unit prisms 40 may be configured to form a Fresnel lens.

  Further, the unit prism 40 is not limited to a linear element arranged one-dimensionally, but may be a dot-like element arranged two-dimensionally to constitute a microlens (fly eye lens).

  Furthermore, the prism sheet 30 may have a diffusion function of diffusing transmitted light. Specifically, the light exit side surface 30a of the prism sheet 30 may be formed as a rough surface, or the prism sheet 30 may include a diffusion component.

  Furthermore, although LED was illustrated as the point light emission member 25 of the light sources 21 and 22 in embodiment mentioned above, it is not restricted to this, You may use another point light emission body. Further, the light emitting member 25 of the light sources 21 and 22 is not limited to the point light emitting member, and a linear light emitting member such as a cold cathode tube may be used.

  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 5 Illuminating system 10 Illuminating device 10a Light-emitting surface 11 Illuminating device 15 Case 16 Reflecting surface 18 Control means 18a 1st switch 18b 2nd switch 21 1st light source 22 2nd light source 25 Light-emitting member 26 Light-emitting body 27 Cap 30 Prism sheet 30a Light emission side surface 30b Light incident side surface 30c1 Edge portion, first edge portion 30c2 Edge portion, second edge portion 35 Main body portion 35b Light incident side surface 40 Unit prism 41 First surface 42 Second surface 50 Light guide plate 50a Light exit surface 55 Base portion 56 Main portion 57 Diffuse component 58 Slope 60 Unit optical element 90 Ceiling 91 Wall 92 Writing board 93 Screen 94 Box

Claims (6)

With a lighting device attached to the ceiling that connects to the wall,
The lighting device includes a first light source and a second light source arranged to face each other in a first direction,
An optical axis caused by light emitted from the first light source in the illumination light from the illumination device is directed to a position on the wall, and the second light source in the illumination light from the illumination device. The optical axis resulting from the light emitted from the head is directed to a position displaced from the wall,
The illumination system capable of controlling the output of light emitted from the first light source independently of the output of light emitted from the second light source. Further comprising a writing board attached to the wall,
2. The illumination system according to claim 1, wherein an optical axis caused by light emitted from the first light source among illumination light from the illumination device is directed to a position on the writing board.   The lighting system according to claim 1, further comprising a screen that can be deployed between the wall and the lighting device. A prism sheet further comprising: a sheet-like main body portion; and a plurality of unit prisms arranged on the main body portion along the first direction,
The prism sheet is arranged such that a unit prism is positioned on the first light source and the second light source side in the normal direction of the prism sheet,
An optical axis caused by light emitted from the first light source of illumination light from the illumination device on a plane parallel to both the normal direction and the first direction of the prism sheet, and the illumination device The optical axis resulting from the light emitted from the second light source among the illumination light from the light is inclined to the opposite sides with respect to the normal direction. Lighting system. The first light source is located on one side in the first direction and emits light from the one side toward the other side opposite to the one side in the first direction,
The second light source is located on the other side in the first direction and emits light from the other side to the one side in the first direction;
Each unit prism has a first surface located on the one side in the first direction, and a second surface located on the other side in the first direction,
In a plane parallel to both the normal direction and the first direction of the prism sheet, the optical axis of the light emitted from the first light source is directed to a position on the prism sheet, and the optical axis The light traveling in the parallel direction is reflected by the second surface after entering the unit prism, and travels in a direction inclined to the one side in the first direction from the normal direction of the prism sheet,
In a plane parallel to both the normal direction and the first direction of the prism sheet, the optical axis of the light emitted from the second light source is directed to a position on the prism sheet, and the optical axis The light traveling in a parallel direction is incident on the unit prism, then reflected by the first surface, and travels in a direction inclined from the normal direction of the prism sheet to the other side in the first direction. The lighting system described in. A light guide plate disposed facing the surface of the prism sheet on which the unit prism is formed,
The first light source is disposed to face a side surface of a light guide plate located on one side in the first direction, and is directed from the one side to the other side opposite to the one side in the first direction. Emit light,
The second light source is disposed to face a side surface of the light guide plate located on the other side in the first direction, emits light so as to go from the other side to the one side in the first direction,
Each unit prism has a first surface located on the one side in the first direction, and a second surface located on the other side in the first direction,
When the angular distribution of luminance in a plane parallel to both the normal direction and the first direction of the prism sheet is measured on the light exit surface of the light guide plate facing the prism sheet, the first light source Light that travels from the output surface of the light guide plate in a direction parallel to the direction that provides the highest luminance in the angular distribution of the luminance on the light output surface of the light guide plate due to the light emitted from the light enters the unit prism. And then reflected by the second surface, and proceeds from the normal direction of the prism sheet to the direction inclined to the one side in the first direction,
When the angular distribution of luminance in a plane parallel to both the normal direction and the first direction of the prism sheet is measured on the light exit surface of the light guide plate facing the prism sheet, the second light source Light that travels from the output surface of the light guide plate in a direction parallel to the direction that provides the highest luminance in the angular distribution of the luminance on the light output surface of the light guide plate due to the light emitted from the light enters the unit prism. 5. The illumination system according to claim 4, wherein the illumination system is reflected by the first surface and proceeds in a direction inclined from the normal direction of the prism sheet to the other side in the first direction.

Images