WO2011093262A1

WO2011093262A1 - Light-guiding plate and lighting device

Info

Publication number: WO2011093262A1
Application number: PCT/JP2011/051302
Authority: WO
Inventors: 敏朗鈴木; 啓介塚田
Original assignee: 日本ゼオン株式会社
Priority date: 2010-01-29
Filing date: 2011-01-25
Publication date: 2011-08-04
Also published as: TW201213902A

Abstract

Disclosed is a light-guiding plate (200) comprising a light introduction face (203) that introduces light; a light extraction face (201) wherein light that is introduced by the light introduction face (203) is extracted; and a rear face (202) that is located opposite to the light extraction face (201). The light-guiding plate (200) is partitioned into a plurality of regions (205, 206), wherein the plurality of regions (205, 206) from among the partitioned regions are respectively anisotropic light extraction regions with higher light extraction efficiencies of light that is guided in parallel to prescribed virtual axes (X, Y) than light extraction efficiencies of light that is guided in a direction that is orthogonal to the virtual axes (X, Y). The location of at least one site (205) from among the anisotropic light extraction regions is location adjusted such that light that is introduced from the corresponding light introducing region (203) within the light-guiding plate (200) arrives at the anisotropic light extraction region (205) via another anisotropic light extraction region (206) with a different virtual axis direction therefrom.

Description

Light guide plate and lighting device

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

Liquid crystal display devices are widely used as display units for liquid crystal televisions, personal computers, mobile phones and the like. The liquid crystal display device usually includes a liquid crystal panel and an illumination device called a backlight device that illuminates the liquid crystal panel from the back.

Examples of the backlight device include a lighting device that combines a light guide plate and a light source that irradiates light to the light guide plate from the side. When the literature described about such a type of illuminating device is given, patent document 1 will be mentioned, for example. In this type of lighting device, light emitted from a light source is introduced into a light guide plate from a light introduction surface located on a side surface of the light guide plate, and the introduced light is light located on the front surface or the back surface of the light guide plate. By emitting from the extraction surface, surface light emission is performed.

JP 2009-224030 A

In recent years, local dimming has attracted attention in the field of liquid crystal display devices. Local dimming is, for example, a technique that does not irradiate light evenly over the entire surface of the liquid crystal panel, but irradiates light only in a desired region or changes the light irradiation intensity for each region. Local dimming is expected to improve the image quality of liquid crystal display devices (for example, improve contrast and reduce afterimages) and save energy.

Therefore, it is desired to develop a technique for realizing local dimming even in the above-described type of lighting device. In order to realize local dimming with the above-mentioned type of lighting device, it is required to selectively extract light from a light extraction surface in a desired region of the light guide plate, and to prevent light from being extracted from other regions. Is required to be suppressed. However, many conventional light guide plates have been developed for the purpose of extracting light evenly from the entire region, and it has been difficult to selectively extract light from a desired region.

In the technique described in Patent Document 1, light is irradiated onto the light guide plate from two directions, ie, the vertical direction and the horizontal direction, and the luminance of the region where the irradiated light intersects is adjusted. However, in the technique described in Patent Document 1, at least two light sources are required for one region, and the configuration tends to be complicated. In addition, since the emission intensity of each of the two light sources that intersect is controlled, the control tends to be complicated.

The present invention was devised in view of the above problems, and a light guide plate that can selectively extract light from a light extraction surface in a desired region, and local dimming with a simple configuration using the light guide plate. An object of the present invention is to provide a lighting device that can be used.

In order to solve the above-described problems and achieve the object, the present invention provides the following [1] to [17].
[1] A light guide plate having a light introduction surface for introducing light, a light extraction surface from which light introduced from the light introduction surface is extracted, and a back surface located on the opposite side of the light extraction surface,
The light guide plate is divided into a plurality of regions as seen from the light extraction direction,
Light that is guided in a direction in which a plurality of regions out of the divided regions are guided in parallel with a predetermined virtual axis parallel to the light extraction surface and intersects the virtual axis. Is an anisotropic light extraction area higher than the extraction efficiency of
The light introduction surface has at least one light introduction region corresponding to each of the anisotropic light extraction regions;
The position of at least one of the anisotropic light extraction regions is such that light introduced from the corresponding light introduction region into the light guide plate passes through another anisotropic light extraction region having a different virtual axis direction. A light guide plate, the position of which is adjusted to reach the isotropic light extraction region.
[2] The light guide plate is divided into a × b regions in a matrix of a rows and b columns (a and b are each an integer of 2 or more) when viewed from the light extraction direction,
The light guide plate according to [1], wherein more than half of the a × b regions are the anisotropic light extraction regions.
[3] The light guide plate according to [2], wherein a and b satisfy 2a + 2b ≧ a × b.
[4] The light guide plate according to any one of [1] to [3], wherein the light guide plate is integrally formed.
[5] For the anisotropic light extraction region, the light is guided to the at least one of the light extraction surface and the back surface in parallel with the virtual axis of the anisotropic light extraction region. Light diffusion that functions as a light extraction pattern for emitting light from the light extraction surface of the extraction region and prevents the light from diffusing with respect to light guided in a direction intersecting the virtual axis of the anisotropic light extraction region The light guide plate according to any one of [1] to [4], wherein the light guide plate is a region where a pattern functioning as a prevention pattern is formed.
[6] The light guide plate according to [5], wherein the light guide plate has a plurality of hook-shaped patterns formed to extend in a direction perpendicular to the virtual axis of the anisotropic light extraction region in which the pattern is formed.
[7] The light guide plate according to [6], wherein the bowl-shaped pattern includes a plurality of prism-like V-groove patterns parallel to each other.
[8] The light guide plate according to [6] or [7], wherein the bowl-shaped pattern includes a plurality of parallel lenticular groove patterns.
[9] An illumination device comprising the light guide plate according to any one of [1] to [8].
[10] The illumination device according to [9], further comprising a light source capable of adjusting light for each of the anisotropic light extraction regions that irradiates light independently to each of the light introduction regions.
[11] A light guide plate provided by stacking two or more sheets,
The light guide plate has a light introduction surface for introducing light, a light extraction surface from which light introduced from the light introduction surface is extracted, and a back surface located on the opposite side of the light extraction surface, and extracts light. Divided into multiple areas as seen from the direction,
A plurality of regions among the divided regions are guided in a direction intersecting with the virtual axis, and light extraction efficiency is guided in a direction parallel to a predetermined virtual axis parallel to the light extraction surface. An anisotropic light extraction area that is higher than the light extraction efficiency
The light introduction surface has light introduction regions provided at least one place corresponding to each of the anisotropic light extraction regions from which light is extracted;
The position of at least one of the anisotropic light extraction regions is such that light introduced from the corresponding light introduction region into the light guide plate passes through another anisotropic light extraction region having a different virtual axis direction. The position is adjusted to reach the isotropic light extraction area,
Furthermore, an illuminating device provided with the light source which can irradiate light to each said light introduction area | region independently and can adjust light for every said anisotropic light extraction area | region.
[12] Each of the light guide plates is divided into a × b regions in a matrix of a rows and b columns (a and b are each an integer of 2 or more) as viewed from the light extraction direction,
The illumination device according to [11], wherein more than half of the a × b regions are the anisotropic light extraction regions.
[13] The illumination device according to [12], wherein when the number of the light guide plates stacked is n, 2 × n × a + 2 × n × b ≧ a × b is satisfied.
[14] The light for the light guided to the anisotropic light extraction region of the light guide plate on at least one of the light extraction surface and the back surface in parallel to the virtual axis of the anisotropic light extraction region. Function as a light extraction pattern for emitting light from the light extraction surface of the anisotropic light extraction region, and the light diffuses for light guided in a direction intersecting the virtual axis of the anisotropic light extraction region. The illumination device according to any one of [11] to [13], wherein the illumination device is a region where a pattern that functions as a light diffusion prevention pattern to be prevented is formed.
[15] The illumination device according to [14], wherein the pattern includes a plurality of hook-shaped patterns formed to extend in a direction orthogonal to the virtual axis of the anisotropic light extraction region where the pattern is formed.
[16] The illumination device according to [15], wherein the bowl-shaped pattern includes a plurality of prism-like V-groove patterns parallel to each other.
[17] The illumination device according to [15] or [16], wherein the bowl-shaped pattern includes a plurality of parallel lenticular groove patterns.

According to the light guide plate of the present invention, light can be selectively extracted from the light extraction surface in a desired region. According to the illumination device of the present invention, local dimming can be realized with a simple configuration.

FIG. 1 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. FIG. 2 is a cross-sectional view schematically showing an enlarged cross section of the light guide plate taken along a plane perpendicular to the Y-axis direction in order to explain how the light guided in the light guide plate travels. FIG. 3 is a cross-sectional view schematically showing an enlarged cross section of the light guide plate taken along a plane perpendicular to the X-axis direction in order to explain how light guided in the light guide plate travels. FIG. 4 is a cross-sectional view schematically showing an enlarged cross section of the light guide plate taken along a plane perpendicular to the Y-axis direction in order to explain how the light guided in the light guide plate travels. FIG. 5 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. FIG. 6 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. FIG. 7 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. FIG. 8 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. FIG. 9 is a perspective view schematically showing the illumination device according to the first embodiment of the present invention. FIG. 10 is a front view schematically showing the illumination device according to the first embodiment of the present invention as viewed from the light extraction surface side in the Z-axis direction. FIG. 11 is a front view schematically showing a state in which the illumination device according to the second embodiment of the present invention is viewed from the light extraction surface side in the Z-axis direction. FIG. 12 is a front view schematically showing a state in which the illumination device according to the third embodiment of the present invention is viewed from the light extraction surface side in the Z-axis direction. FIG. 13 is a perspective view schematically showing an illumination apparatus according to the fourth embodiment of the present invention. FIG. 14 is an exploded perspective view schematically showing an exploded state of the illumination device according to the fourth embodiment of the present invention. FIG. 15 schematically shows a light guide plate in a lighting device according to a fourth embodiment of the present invention and a light source that irradiates light on the side surface of the light guide plate as viewed from the light extraction surface side in the Z-axis direction. FIG. FIG. 16 schematically shows a light guide plate in a lighting device according to a fourth embodiment of the present invention and a light source that irradiates light on the side surface of the light guide plate as viewed from the light extraction surface side in the Z-axis direction. FIG. FIG. 17 is a perspective view schematically showing an illumination apparatus according to the fifth embodiment of the present invention. FIG. 18 is a cross-sectional view schematically showing the vicinity of the light source of the illumination device configured in the example.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples, and the claims of the present invention and equivalents thereof. Any change can be made without departing from the scope.
In the following description, the directions of the components are “parallel” and “orthogonal” unless otherwise specified, including errors within a range that does not impair the effects of the present invention, for example, within ± 5 °. May be. Further, “along” in a certain direction means “in parallel” in a certain direction. Furthermore, in the description of the position of each area of the light guide plate, “near” means a position close to the light introduction area corresponding to the area, and “back” means a position far from the light introduction area corresponding to the area. Say.

[Anisotropic light extraction area]
The light guide plate of the present invention has a light introduction surface for introducing light, a light extraction surface from which light introduced from the light introduction surface is extracted, and a back surface located on the opposite side of the light extraction surface. The light guide plate of the present invention has an “anisotropic light extraction region”. An anisotropic light extraction region is an extraction efficiency of light guided in a direction parallel to a predetermined virtual axis parallel to the light extraction surface, more than the extraction efficiency of light guided in a direction intersecting the virtual axis. It means the high area. Moreover, the area | region of a light-guide plate means the area | region divided seeing from the extraction direction of light unless there is particular notice. In addition, the light extraction direction refers to a direction in which the light intensity is the highest among the traveling directions of the light extracted from the light extraction surface of the light guide plate, unless otherwise specified. However, in general, the direction of light extracted from the light guide plate is not perpendicular to the light extraction surface but has a certain angle. For this reason, the lights that have entered from different light guiding directions and are extracted by a pattern that will be described later are usually not parallel to each other. However, in this specification, for ease of understanding, unless otherwise specified, “light extraction direction” is described as the Z-axis direction, which is the normal direction of the light extraction surface. Further, to divide the light guide plate into a plurality of regions “when viewed from the light extraction direction” means to divide the light guide plate into a plurality of regions on a plane parallel to the light extraction direction.

Furthermore, the direction in which light is guided (hereinafter referred to as “light guide direction” as appropriate) refers to the direction in which light is guided in the light guide plate when viewed from the light extraction direction, unless otherwise specified. Point to. Therefore, when referring to the light guide direction, the Z-axis direction described later is not a problem unless otherwise specified. For this reason, in the anisotropic light extraction region, the direction intersecting with the predetermined virtual axis of the anisotropic light extraction region indicates the light guide direction, and therefore is a direction parallel to the light extraction surface and intersecting the virtual axis. Means that.
Hereinafter, an anisotropic light extraction region according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. As shown in FIG. 1, the light guide plate 100 of this example has a rectangular plate shape. The light guide plate 100 has a light extraction surface 101 and a back surface 102 located on the opposite side of the light extraction surface 101 as its main surface. Furthermore, the light guide plate 100 has

side surfaces

103 and 104 that are orthogonal to each other at the ends of the light extraction surface 101 and the back surface 102.

Here, the thickness direction of the light guide plate 100 is defined as the Z-axis direction. Of the directions parallel to the plane perpendicular to the Z-axis direction, the direction parallel to one side of the rectangle of the light extraction surface 101 is defined as the X-axis direction, and the direction orthogonal to the X-axis direction is defined as the Y-axis direction. The light extraction surface 101 and the back surface 102 are both surfaces perpendicular to the Z-axis direction, the side surface 103 is a surface perpendicular to the X-axis direction, and the side surface 104 is a surface perpendicular to the Y-axis direction. Furthermore, it is assumed that the light extraction direction from the light extraction surface 101 is parallel to the Z-axis direction. Since the light extraction surface 101 has a pattern 105 as will be described later, it is not a flat plane when viewed microscopically. However, since the pattern 105 has a small size, the light extraction surface 101 is It can be handled as a flat plane. Therefore, the light extraction surface 101 being perpendicular to the Z-axis direction means that a plane when the light extraction surface 101 is viewed macroscopically is perpendicular to the Z-axis direction.

In the light guide plate 100, the back surface 102, the side surface 103, and the side surface 104 are flat planes. On the other hand, the light extraction surface 101 has a plurality of bowl-shaped patterns 105 formed extending in the Y-axis direction on the entire surface.
As shown in FIG. 1, the pattern 105 is a prism-like V-groove pattern parallel to each other. That is, the grooves whose cross sections are V-shaped are formed in parallel to each other. Therefore, the pattern 105 has the slope 106 and the slope 107 which consist of a plane parallel to a Y-axis direction, respectively. The slope 106 and the slope 107 are inclined in directions opposite to each other with respect to the light extraction surface 101 (as described above, it is a flat surface when viewed macroscopically). Further, on the light extraction surface 101, the slopes 106 and the slopes 107 are alternately present in the X-axis direction.

The slope 106 and the slope 107 are not parallel to the X-axis direction. That is, the slope 106 and the slope 107 each intersect the X-axis direction. Therefore, the pattern 105 having the slope 106 and the slope 107 functions as a light extraction pattern for emitting light from the light exit surface 101 for light guided in parallel with the X-axis direction. It does not function as a light extraction pattern for light guided in parallel. A pattern in which the light extraction efficiency differs depending on the light guide direction is referred to as an “anisotropic pattern” as appropriate.

FIG. 2 is a cross-sectional view schematically showing an enlarged cross section of the light guide plate 100 taken along a plane perpendicular to the Y-axis direction in order to explain how light guided in the light guide plate 100 in this example travels. It is. 2, the same reference numerals as those in FIG. 1 indicate the same elements as those in FIG. 1. In FIG. 2, an arrow A <b> 103 indicates a component perpendicular to the Y-axis direction among light vectors guided through the light guide plate 100. As shown in FIG. 1, it is assumed that the side surface 103 is a light introduction region and the light A 103 is introduced from the side surface 103 to the light guide plate 100. When the light A103 is introduced from the side surface 103, the introduced light A103 is guided along the X-axis direction while repeating internal reflection on the light extraction surface 101 and the back surface 102 as shown in FIG. While repeating internal reflection, the light A103 is incident on the slope 106 or slope 107 of the pattern 105 at a small incident angle. When the light A 103 is incident on the inclined surface 106 or the inclined surface 107 at an incident angle that is small enough to prevent internal reflection, the light A 103 is extracted from the inclined surface 106 or the inclined surface 107 to the outside of the light guide plate 100. In this way, the pattern 105 functions as a light extraction pattern for the light A103 guided in parallel with the X-axis direction.
In FIG. 2, the light A103 guided in the right light guide direction in the drawing has been described. Conversely, the pattern 105 similarly applies to the light guided in the left light guide direction in the drawing. Function as.

FIG. 3 is a cross-sectional view schematically showing an enlarged cross section of the light guide plate 100 taken along a plane perpendicular to the X-axis direction in order to explain how light guided in the light guide plate 100 in this example travels. It is. 3, the same reference numerals as those in FIG. 1 denote the same elements as those in FIG. In FIG. 3, an arrow A <b> 104 indicates a component perpendicular to the X-axis direction among light vectors guided through the light guide plate 100. As shown in FIG. 1, it is assumed that the side surface 104 is a light introduction region and the light A 104 is introduced from the side surface 104 to the light guide plate 100. When the light A104 is introduced from the side surface 104, the introduced light A104 is guided along the Y-axis direction while repeating internal reflection on the light extraction surface 101 and the back surface 102 as shown in FIG.
Here, the light vector of the light A104 is decomposed into an X-axis direction component parallel to the X-axis direction, a Y-axis direction component parallel to the Y-axis direction, and a Z-axis direction component parallel to the Z-axis direction. In the light A104 guided in parallel with the Y-axis direction, the Y-axis direction component tends to be larger than the X-axis direction component and the Z-axis direction component. For this reason, it is difficult for the light A104 to enter the inclined surface 106 and the inclined surface 107 parallel to the Y-axis direction at a small incident angle. Therefore, the pattern 105 having the slope 106 and the slope 107 does not function as a light extraction pattern with respect to the light A 104 guided in parallel with the Y-axis direction. That is, even if the pattern 105 does not exhibit the function of extracting the light A104 or exhibits the function, the degree is smaller than the light A103 guided in parallel with the X-axis direction.
In FIG. 3, the light A104 guided in the right light guide direction in the drawing has been described. Conversely, the pattern 105 similarly applies to the light guided in the left light guide direction in the drawing. Does not function as.

As described above, the pattern 105 functions as an anisotropic pattern. Therefore, in the light guide plate 100, the extraction efficiency of the light A103 guided in the light guide direction parallel to the X axis direction is guided in the light guide direction parallel to the Y axis direction, which is a direction intersecting the X axis direction. The extraction efficiency of the light A104 is higher.

Here, an X axis extending in the X axis direction is assumed as one virtual axis (predetermined virtual axis) parallel to the light extraction surface 101. Then, the X-axis direction that is the light guide direction of the light A103 is a light guide direction parallel to the X-axis (that is, a predetermined virtual axis parallel to the light extraction surface 101). The Y-axis direction that is the light guide direction of the light A 104 is parallel to the light extraction surface 101 and is a light guide direction that intersects the X axis that is the virtual axis. Therefore, in the entire region of the light guide plate 100, the extraction efficiency of the light A103 guided in parallel with the predetermined virtual axis (X axis) parallel to the light extraction surface 101 is guided so as to intersect the virtual axis (X axis). This is higher than the extraction efficiency of the light A104 guided in the light direction (Y-axis direction). As described above, the region of the light guide plate 100 having anisotropy in the light extraction efficiency corresponds to the anisotropic light extraction region.

In addition, when the light guide plate has a plurality of anisotropic light extraction regions, the light guide direction in which the light extraction efficiency is high is usually set for each anisotropic light extraction region. Therefore, the virtual axis is usually set for each anisotropic light extraction region.

By the way, the pattern 105 functions as a light diffusion prevention pattern for preventing the light A104 from being diffused in the X-axis direction with respect to the light A104 guided in the Y-axis direction. Therefore, the pattern 105 can prevent the light A104 from being guided so as to spread in the X-axis direction. This will be described with reference to the drawings.

FIG. 4 is a cross-sectional view schematically showing an enlarged cross section of the light guide plate 100 taken along a plane perpendicular to the Y-axis direction in order to explain how light guided in the light guide plate 100 in this example travels. It is. 4, the same reference numerals as those in FIG. 1 indicate the same elements as those in FIG. 1. Further, in FIG. 4, an arrow A <b> 104 indicates a component perpendicular to the Y-axis direction among light vectors guided through the light guide plate 100. As described above, the light A104 guided in parallel with the Y-axis direction has a tendency that the X-axis direction component and the Z-axis direction component are smaller than the Y-axis direction component. Therefore, most of the light A 104 is internally reflected on the slope 106 and the slope 107. At this time, since the slope 106 and the slope 107 are inclined so as to intersect the X-axis direction, the light A104 is internally reflected so as not to spread in the X-axis direction. That is, while the light A104 repeats internal reflection on the slope 106 or the slope 107, the direction of the vector of the Y-axis direction component of the light A104 is repeatedly reversed. Therefore, most of the light A104 guided in parallel with the Y-axis direction cannot continue to travel continuously in one or the other in the X-axis direction and does not diffuse in the X-axis direction. That is, the pattern 105 prevents the light A104 guided in the Y-axis direction (light guide direction intersecting the virtual axis) from being spread and guided in the X-axis direction (light guide direction parallel to the virtual axis). It demonstrates its function. In this way, the pattern 105 functions as a light diffusion prevention pattern that suppresses the diffusion of the light A104 in the X-axis direction.
In addition, although FIG. 4 demonstrated the light A104 guided in the right light guide direction in the drawing, the pattern 105 similarly prevents light diffusion for the light guided in the left light guide direction in the drawing. Acts as a pattern.

The pattern formed in the anisotropic light extraction region of the light guide plate is usually an anisotropic pattern having different light extraction efficiency depending on the light guide direction as described above. Further, the pattern formed in the anisotropic light extraction region of the light guide plate is preferably an anisotropic pattern that functions as a light diffusion prevention pattern, like the pattern 105. By functioning as a light diffusion prevention pattern, the guided light can be prevented from being guided to a region other than the desired region. As a result, it is also possible to prevent light from being extracted from the light extraction surface in a region other than the desired region. Therefore, advantages such as image quality improvement and energy saving of the liquid crystal display device including the light guide plate can be obtained.

The anisotropic pattern that also functions as a light diffusion prevention pattern as described above can be realized by, for example, a bowl-shaped pattern formed on the surface of the light guide plate. The hook-shaped pattern is usually formed so as to extend in a direction orthogonal to the virtual axis of the anisotropic light extraction region where the hook-shaped pattern is formed.

The following examples are given as examples of the shape of the bowl-shaped pattern.
For example, like the pattern 105 shown in FIG. 1, the saddle-like pattern has a triangular cross-sectional shape cut by a plane perpendicular to the extending direction of the pattern 105 (Y-axis direction in FIG. 1). The shape which becomes may be sufficient. Such a hook-shaped pattern is called a triangular cross-sectional pattern. Here, the apex angle of the triangular cross section is preferably 30 ° to 120 ° as a diffusion preventing function, and more preferably 60 ° to 90 °.

FIG. 5 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. In FIG. 5, the same reference numerals as those in FIGS. 1 to 4 denote the same elements as those in FIGS. The hook-shaped patterns may be formed side by side without a gap as shown in FIG. 1, but may be formed side by side with a predetermined gap. For example, a pattern in which V-grooves are formed at a predetermined interval, such as a pattern 108 shown in FIG. The pattern 108 having such a shape also corresponds to a prism-like V-groove pattern. The pattern 108 shown in FIG. 5 has a trapezoidal shape with a cross section taken along a plane perpendicular to the extending direction of the pattern 108 (Y-axis direction in FIG. 5). The bowl-shaped pattern 108 having such a shape is called a cross-sectional trapezoidal pattern.

When the bowl-shaped pattern 108 is a trapezoidal cross-sectional pattern, the pattern 108 has a slope 106 and a slope 107, respectively. The pattern 108 has a flat surface 109 perpendicular to the Z-axis direction between the slope 106 and the slope 107. Since it has the

slopes

106 and 107, the pattern 108 which is a trapezoidal cross-sectional pattern functions as an anisotropic pattern and also functions as a light diffusion prevention pattern like the pattern 105 shown in FIG.

The bowl-shaped pattern may be, for example, a shape in which a cross-sectional shape cut by a plane perpendicular to the extending direction of the pattern is a triangle or more. Even in the case of such a bowl-shaped pattern, since it has an inclined surface, it functions as an anisotropic pattern and also functions as a light diffusion prevention pattern, similar to the pattern 105 shown in FIG.

FIG. 6 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. In FIG. 6, the same reference numerals as those in FIGS. 1 to 5 denote the same elements as those in FIGS. The saddle-like pattern may be a lenticular groove pattern, for example, like a pattern 110 shown in FIG. The lenticular groove pattern is, for example, a shape of a cross section cut by a plane perpendicular to the extending direction of the pattern 110 (Y-axis direction in FIG. 6), or a partial shape of a circle or an ellipse (for example, a semicircle, A semi-elliptical shape.

When the bowl-shaped pattern 110 is a lenticular groove pattern, the surface 111 of the pattern 110 is formed as a smooth curved surface, and gradually inclines with respect to the light extraction surface 101 from the center to the end in the X-axis direction. To go. Thus, since the surface 111 of the pattern 110 is inclined as described above, the surface 111 has a portion that is not parallel to the X-axis direction (that is, intersects with the X-axis). Portions that are not parallel to the X-axis direction of the surface 111 function in the same manner as the

slopes

106 and 107 of the V-shaped

groove patterns

105 and 108. Therefore, the pattern 110 which is a lenticular groove pattern also functions as an anisotropic pattern and also functions as a light diffusion prevention pattern, like the

patterns

105 and 108 shown in FIGS. Here, the groove pattern of the lenticular may be a shape obtained by cutting off a part of a circle or an ellipse. In that case, the height / radius ratio is preferably 1/3 or more, more preferably 1/2 or more, More preferably, it is 1/1 or more, but from the viewpoint of creating the shape, a shape of 3/1 or less is preferable.

The

patterns

105, 108, and 110 may be formed on at least one of the light extraction surface 101 and the back surface 102 of the light guide plate 100. Therefore, the

patterns

105, 108, and 110 may be formed on the back surface 102 in addition to being formed on the light extraction surface 101 as shown in FIGS. 1, 5, and 6. You may make it form in both the back surfaces 102. FIG. When the

patterns

105, 108, and 110 are formed on both the light extraction surface 101 and the back surface 102, the

patterns

105, 108, and 110 may adopt the same pattern on the light extraction surface 101 and the back surface 102, but are different. A pattern may be adopted. Furthermore, the

patterns

105, 108, and 110 may form only one type of structure in the region where the

patterns

105, 108, and 110 are formed, but two or more types of structures may be combined in the region. Also good.

FIG. 7 is a perspective view schematically showing an example of a light guide plate having an anisotropic light extraction region. In FIG. 7, the same reference numerals as those in FIGS. 1 to 6 denote the same elements as those in FIGS. Functions similar to the anisotropic pattern and the light diffusion prevention pattern can be realized by a configuration other than the pattern formed on the light extraction surface 101 or the back surface 102. For example, as shown in FIG. 7, the light guide plate 100 may have a shape having a swell extending only in one direction (the Y-axis direction in FIG. 7). In this case, the light guided in the light guide direction parallel to the X-axis direction is incident on the light extraction surface 101 at an incident angle that is small enough to prevent partial internal reflection during the light guide process. 101 is taken out. On the other hand, light guided in the light guide direction parallel to the Y-axis direction is difficult to be incident on the light extraction surface 101 at a small incident angle, and thus is difficult to be extracted from the light extraction surface 101.

As described above, the anisotropic light extraction region can be implemented in various modes. For example, a diffusion material having a refractive index difference and an anisotropic shape with a material of a light guide plate material (hereinafter referred to as “base material” as appropriate) is prepared, and this diffusion agent is included in the base material. It is also possible to form an anisotropic light extraction region by orienting the diffusing agent by applying processes such as shearing and stretching. Furthermore, a hollow hole is formed in one direction in the base material by profile extrusion or the like, and this can be used as an anisotropic light extraction region. It is possible to form the light guide plate according to the present invention by cutting them into appropriate sizes and optically bonding them.

By the way, in the anisotropic light extraction region, light tends to be extracted with higher brightness usually at a position closer to the light introduction region. For this reason, when an anisotropic light extraction area | region has the said hook-shaped pattern, it is preferable to adjust the space | interval of a pattern or a size. Specifically, by adjusting the pattern pitch (interval), width, height, etc., the density or size of the pattern increases continuously or stepwise as it goes farther away from the light introduction region. It is preferable to do. Thereby, since it becomes possible to extract light efficiently as it goes deeper, luminance unevenness on the light extraction surface in the anisotropic light extraction region can be suppressed. Further, with respect to the pattern, in order to prevent unevenness in which the pattern appears as a line, both the width of the outgoing light line and the width of the gap are preferably about 0.3 mm or less, and more preferably 0.1 mm or less. preferable.

〔Positioning〕
The light guide plate of the present invention is divided into a plurality of regions when viewed from the light extraction direction, and a plurality of regions among the divided regions are anisotropic light extraction regions. Moreover, the light introduction surface of the light guide of the present invention has at least one light introduction region corresponding to each anisotropic light extraction region from which light is to be extracted.
Further, at least one position of the anisotropic light extraction region is such that light introduced from the corresponding light introduction region into the light guide plate is guided through another anisotropic light extraction region having a different virtual axis direction, The position is adjusted so as to reach the anisotropic light extraction region.
Hereinafter, this position adjustment will be described with reference to the drawings.

FIG. 8 is a perspective view schematically showing an example of the light guide plate 200 having an anisotropic light extraction region. As shown in FIG. 8, the light guide plate 200 of this example has a rectangular plate shape. The light guide plate 200 has a light extraction surface 201 and a back surface 202 located on the opposite side of the light extraction surface 201 as its main surface. Furthermore, the light guide plate 200 has

side surfaces

203 and 204 that are orthogonal to each other at the ends of the light extraction surface 201 and the back surface 202.

Here, the thickness direction of the light guide plate 200 is defined as the Z-axis direction. Of the directions parallel to the plane perpendicular to the Z-axis direction, the direction parallel to one side of the rectangle of the light extraction surface 201 is defined as the X-axis direction, and the direction orthogonal to the X-axis direction is defined as the Y-axis direction. The light extraction surface 201 and the back surface 202 are both surfaces perpendicular to the Z-axis direction, the side surface 203 is a surface perpendicular to the X-axis direction, and the side surface 204 is a surface perpendicular to the Y-axis direction. Furthermore, it is assumed that the light extraction direction from the light extraction surface 201 is parallel to the Z-axis direction. The light extraction surface 201 has a pattern 207 and a pattern 208, which will be described later, and is not a flat plane when viewed microscopically, but can be handled as a flat plane when viewed macroscopically.

The light guide plate 200 is divided into two

regions

205 and 206 as viewed from the light extraction direction (in FIG. 8, the light extraction surface side in the Z-axis direction). Here, it is assumed that the region 205 and the region 206 are arranged side by side in the X-axis direction as shown in FIG.

A pattern 207 that functions as an anisotropic pattern and a light diffusion prevention pattern is formed on the light extraction surface 201 in the region 205. The pattern 207 is an anisotropic pattern in which the X axis parallel to the X axis direction is a predetermined virtual axis. Therefore, the pattern 207 functions as a light extraction pattern for light guided in parallel with the X-axis direction. The pattern 207 does not function as a light extraction pattern for light guided in parallel with the Y-axis direction but functions as a light diffusion prevention pattern.

On the light extraction surface 201 in the region 206, a pattern 208 that functions as an anisotropic pattern and a light diffusion prevention pattern is formed. The pattern 208 is an anisotropic pattern having a Y axis parallel to the Y axis direction as a predetermined virtual axis. Therefore, the pattern 208 functions as a light extraction pattern for light guided in parallel with the Y-axis direction. The pattern 208 does not function as a light extraction pattern for light guided in parallel with the X-axis direction, but functions as a light diffusion prevention pattern.

Furthermore, in the light guide plate 200, the side surface 203 and the side surface 204 are light introduction surfaces. Of these, the entire side surface 203 is a light introduction region corresponding to the region 205. Further, a portion 209 of the side surface 204 located on the near side in the Y-axis direction of the region 206 is a light introduction region of the region 206.

In such a light guide plate 200, the region 205 passes through a region 206 (another anisotropic light extraction region) in which the light introduced from the side surface 203 (the light introduction region corresponding to the region 205) has a different virtual axis direction. The light is guided and the position is adjusted so as to reach the region 205.
Therefore, when light is introduced from the side surface 203 into the light guide plate 200, the introduced light is guided through the region 206 and then reaches the region 205.

That is, when light is introduced from the side surface 203, the light is guided in parallel with the X-axis direction and passes through the region 206. Since the pattern 208 does not function as a light extraction pattern with respect to light introduced from the side surface 203, light passing through the region 206 is not extracted from the light extraction surface 201 in the region 206. In addition, since the pattern 208 functions as a light diffusion prevention pattern for the light passing through the region 206, diffusion of light in the Y-axis direction is prevented in the region 206.

The light that has passed through the region 206 is subsequently guided in parallel with the X-axis direction and reaches the region 205. Since diffusion of light in the region 206 is prevented, most of the light introduced from the side surface 203 efficiently reaches the region 205. The reached light is extracted from the light extraction surface 201 in the region 205 when the pattern 207 functions as a light extraction pattern.

As described above, in the light guide plate 200, light reaching the region 205 having the predetermined virtual axis in the X-axis direction is guided through the region 206 having the predetermined virtual axis in the Y-axis direction, and then the region The positions of the

areas

205 and 206 are adjusted so as to reach 205. In the light guide plate of the present invention, the position of at least one of the plurality of anisotropic light extraction regions is adjusted as in the region 205. By such position adjustment, the position of the light extraction area can be set with a high degree of freedom.

When light is extracted from the region 206 of the light guide plate 200, light can be introduced from the portion 209 of the side surface 204 that is a light introduction region corresponding to the region 206.
Further, when light is introduced into the light guide plate from the light introduction region, the light introduction region is irradiated with light from a light source (not shown). At this time, the direction of light emitted from the light source is preferably a direction parallel to the virtual axis of the anisotropic light extraction region corresponding to the light introduction region and a direction parallel to the light extraction surface. This is to effectively take out the light and prevent diffusion.

[First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a perspective view schematically showing the illumination device according to the first embodiment of the present invention. As shown in FIG. 9, the illumination device 1 according to the first embodiment of the present invention includes a single light guide plate 300 and light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444.

As shown in FIG. 9, the light guide plate 300 has a rectangular plate shape. The light guide plate 300 has a light extraction surface 301 and a back surface 302 located on the opposite side of the light extraction surface 301 as its main surface. Further, the light guide plate 300 has four side surfaces 303 to 306 as light introduction surfaces at the ends of the light extraction surface 301 and the back surface 302.

Here, the thickness direction of the light guide plate 300 is defined as the Z-axis direction. Of the directions parallel to the plane perpendicular to the Z-axis direction, the direction parallel to one side of the rectangle of the light extraction surface 301 is defined as the X-axis direction, and the direction orthogonal to the X-axis direction is defined as the Y-axis direction. The light extraction surface 301 and the back surface 302 are both surfaces perpendicular to the Z-axis direction, the side surface 303 and the side surface 305 are surfaces perpendicular to the X-axis direction, and the side surface 304 and the side surface 306 are perpendicular to the Y-axis direction. Suppose that it is a surface. Furthermore, it is assumed that the light extraction direction from the light extraction surface 301 is parallel to the Z-axis direction.

The light guide plate 300 is divided into 16 regions in a matrix of 4 rows and 4 columns as viewed from the light extraction direction (in FIG. 9, the light extraction surface side in the Z-axis direction). Specifically, as shown in FIG. 9, it is divided into four rows at equal intervals in the X-axis direction, and is divided into four columns at equal intervals in the Y-axis direction. Thus, the light guide plate 300 has regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 having four rows in the X-axis direction and four columns in the Y-axis direction.
However, the above-mentioned areas 311 to 314, 321 to 324, 331 to 334, and 341 to 344 are set to control the position from which light is extracted, and each area is physically separated by barriers and disconnection. It does not have to be.

It should be noted that in the following reference numerals of the regions of the light guide plate, the number of the tens place corresponds to the row of the matrix, and the number of the one place corresponds to the column of the matrix. Therefore, the code of the region in the a-th row and the b-th column is indicated by “3ab”. For example, in the light guide plate 300 according to the present embodiment, the code of the region located in the second column of the first row is “312”.

FIG. 10 is a front view schematically showing the illumination device 1 according to the first embodiment of the present invention as viewed from the light extraction surface side in the Z-axis direction. 10, the same reference numerals as those in FIG. 9 indicate the same elements as those in FIG. As shown in FIG. 10, the above-mentioned regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 are all anisotropic light extraction regions. The positions of the

regions

312, 322, 323, 324, 331, 332, 333 and 343, which are anisotropic light extraction regions, indicate that the light introduced into the light guide plate 300 from the corresponding light introduction region has the direction of the virtual axis The position is adjusted so that the light is guided through another different anisotropic light extraction region and then reaches the

region

312, 322, 323, 324, 331, 332, 333, 343. From another point of view, the positions of the

regions

312, 322, 323, 324, 331, 332, 333, and 343, which are anisotropic light extraction regions, are introduced into the light guide plate 300 from the corresponding light introduction regions. The position is adjusted so as to reach the

regions

312, 322, 323, 324, 331, 332, 333, and 343 without passing through other anisotropic light extraction regions having parallel virtual axis directions.

Specifically, one or both of the light extraction surface 301 and the back surface 302 in the

regions

312, 314, 321, 323, 332, 334, 341, and 343 is directed to the light guided in parallel in the X-axis direction. Functions as a light extraction pattern, and does not function as a light extraction pattern for light guided in parallel to the Y-axis direction, but forms a pattern that functions as a light diffusion prevention pattern. Accordingly, in the

regions

312, 314, 321, 323, 332, 334, 341, 343, the light guided in parallel to the X-axis direction is extracted from the light extraction surface 301 and guided in parallel to the Y-axis direction. Light is guided along the Y-axis direction without being extracted.

In addition, one or both of the light extraction surface 301 and the back surface 302 in the

regions

311, 313, 322, 324, 331, 333, 342, and 344 are light extraction for light guided parallel to the Y-axis direction. A pattern that functions as a pattern and does not function as a light extraction pattern for light guided parallel to the X-axis direction, but functions as a light diffusion prevention pattern is formed. Therefore, in the

regions

311, 313, 322, 324, 331, 333, 342, and 344, the light guided in parallel to the Y-axis direction is extracted from the light extraction surface 301 and guided in parallel to the X-axis direction. Light is guided along the X-axis direction without being extracted.

In the illumination device 1 according to the present embodiment, light is extracted from the light extraction surfaces 301 in all the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 of the light guide plate 300. Therefore, as shown in FIG. 10, the side surfaces 303 to 306 that are the light introduction surfaces of the light guide plate 300 correspond to the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344, respectively, from which light is to be extracted. And at least one light introduction region.

Specifically, the light introduction regions 303a to 303d are formed by dividing the side surface 303 at equal intervals in the Y-axis direction. As shown in FIG. 10, the light introduction region 303a is a region located on the left side of the region 311 in the drawing, the light introduction region 303b is a region located on the left side of the region 321 in the drawing, and the light introduction region 303c is a region 331. The light introduction region 303d is a region located on the left side of the region 341 in the drawing.

Further, the light introduction regions 304a to 304d are formed by dividing the side surface 304 at equal intervals in the X-axis direction. As shown in FIG. 10, the light introduction region 304a is a region located below the region 341 in the drawing, the light introduction region 304b is a region located below the region 342 in the drawing, and the light introduction region 304c is The region 343 is a region located on the lower side in the drawing, and the light introduction region 304d is a region located on the lower side of the region 344 in the drawing.

Further, the light introduction regions 305a to 305d are formed by dividing the side surface 305 at equal intervals in the Y-axis direction. As illustrated in FIG. 10, the light introduction region 305 a is a region located on the right side of the region 314 in the drawing, the light introduction region 305 b is a region located on the right side of the region 324 in the drawing, and the light introduction region 305 c is the region 334. The light introduction region 305d is a region located on the right side of the region 344 in the drawing. Accordingly, the light introduction regions 305a to 305d are located on the opposite sides of the light introduction regions 303a to 303d, respectively.

Furthermore, the light introduction regions 306a to 306d are formed by dividing the side surface 306 at equal intervals in the X-axis direction. As illustrated in FIG. 10, the light introduction region 306 a is a region located on the upper side of the region 311 in the drawing, the light introduction region 306 b is a region located on the upper side of the region 312 in the drawing, and the light introduction region 306 c is the region 313. The light introduction region 306d is a region located on the upper side of the region 314 in the drawing. Therefore, the light introduction regions 306a to 306d are located on the opposite sides of the light introduction regions 304a to 304d, respectively.

The light introduction areas 303a to 303d, 304a to 304d, 305a to 305d, and 306a to 306d are set for controlling the light emission position of the lighting device 1, and are usually physically separated by boundaries. It is not something.

The light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 are devices that irradiate light to the side surfaces 303 to 306 that are light introduction surfaces of the light guide plate 300. As the light sources 411 to 414, 421 to 424, 431 to 434, 441 to 444, for example, LEDs (Light Emitting Diode) are used. LEDs are high light emission efficiency and are excellent light sources from the viewpoint of energy saving. The LED is supplied with electric power from a power source (not shown), and can be individually dimmed by the supplied electric power.

From the viewpoint of realizing local dimming, the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 emit light independently to the light introduction regions 303a to 303d, 304a to 304d, 305a to 305d, and 306a to 306d, respectively. It is provided so that can be irradiated. As a result, the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 can be dimmed for each of the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344. . The light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 correspond to the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344, respectively, from which light is to be extracted. It may be provided, or a group of groups including two or more light sources may be provided. However, in any case, the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 are individually or grouped for each of the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 from which light is to be extracted. It is preferable to be dimmable every time.

Specifically, the light introduction region 306a on the side surface 306 corresponds to the region 311 and a light source 411 is provided in front of the region 306a.
The light introduction region 303a on the side surface 303 corresponds to the region 312 and a light source 412 is provided in front of the region 303a.
A light introduction region 306c on the side surface 306 corresponds to the region 313, and a light source 413 is provided in front of the region 306c.
A light introduction region 305a on the side surface 305 corresponds to the region 314, and a light source 414 is provided in front of the region 305a.
A light introduction region 303b on the side surface 303 corresponds to the region 321 and a light source 421 is provided in front of the region 303b.
A light introduction region 306b on the side surface 306 corresponds to the region 322, and a light source 422 is provided in front of the region 306b.
A light introduction region 305b on the side surface 305 corresponds to the region 323, and a light source 423 is provided in front of the region 305b.
A light introduction region 306d on the side surface 306 corresponds to the region 324, and a light source 424 is provided in front of the region 306d.
A light introduction region 304a on the side surface 304 corresponds to the region 331, and a light source 431 is provided in front of the region 304a.
The light introduction region 303c on the side surface 303 corresponds to the region 332, and a light source 432 is provided in front of the region 303c.
A light introduction region 304c on the side surface 304 corresponds to the region 333, and a light source 433 is provided in front of the region 304c.
A light introduction region 305c on the side surface 305 corresponds to the region 334, and a light source 434 is provided in front of the region 305c.
The light introduction region 303d on the side surface 303 corresponds to the region 341, and a light source 441 is provided in front of the region 303d.
A light introduction region 304b on the side surface 304 corresponds to the region 342, and a light source 442 is provided in front of the region 304b.
A light introduction region 305d on the side surface 305 corresponds to the region 343, and a light source 443 is provided in front of the region 305d.
Further, the light introduction region 304d on the side surface 304 corresponds to the region 344, and a light source 444 is provided in front of the region 304d.

Note that the dimming of the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 only needs to change at least the intensity of light emission. Therefore, as the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444, those that can normally be turned off are used, but they can be used if they are not completely extinguished and can adjust the brightness. It is. In this embodiment, the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 are connected to a power source (not shown) so that light can be emitted with a desired brightness by adjusting the supplied power. Suppose that

The lighting device 1 according to the first embodiment of the present invention is configured as described above. Therefore, in use, the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 corresponding to the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 from which light is to be extracted have a desired brightness. Select to emit light.

For example, when light is to be extracted from the light extraction surface 301 in the region 311, the light source 411 is caused to emit light. When the light source 411 emits light, the light introduction region 306a on the side surface 306 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 306a. The introduced light is extracted from the light extraction surface 301 in the region 311.

For example, when light is to be extracted from the light extraction surface 301 in the region 312, the light source 412 is caused to emit light. When the light source 412 emits light, the light introduction region 303a of the side surface 303 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 303a. The introduced light is guided through the region 311, reaches the region 312, and is extracted from the light extraction surface 301 in the region 312.

For example, when light is to be extracted from the light extraction surface 301 in the region 313, the light source 413 is caused to emit light. When the light source 413 emits light, the light introduction region 306c on the side surface 306 is irradiated with light, and the light is introduced into the light guide plate 300 from the light introduction region 306c. The introduced light is extracted from the light extraction surface 301 in the region 313.

For example, when light is to be extracted from the light extraction surface 301 in the region 314, the light source 414 is caused to emit light. When the light source 414 emits light, the light introduction region 305a on the side surface 305 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 305a. The introduced light is extracted from the light extraction surface 301 in the region 314.

For example, when light is to be extracted from the light extraction surface 301 in the region 321, the light source 421 is caused to emit light. When the light source 421 emits light, light is irradiated to the light introduction region 303b of the side surface 303, and light is introduced into the light guide plate 300 from the light introduction region 303b. The introduced light is extracted from the light extraction surface 301 in the region 321.

For example, when light is to be extracted from the light extraction surface 301 in the region 322, the light source 422 is caused to emit light. When the light source 422 emits light, the light introduction region 306b of the side surface 306 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 306b. The introduced light is guided through the region 312, reaches the region 322, and is extracted from the light extraction surface 301 in the region 322.

For example, when light is to be extracted from the light extraction surface 301 in the region 323, the light source 423 is caused to emit light. When the light source 423 emits light, the light introduction region 305b of the side surface 305 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 305b. The introduced light is guided through the region 324, reaches the region 323, and is extracted from the light extraction surface 301 in the region 323.

For example, when light is to be extracted from the light extraction surface 301 in the region 324, the light source 424 is caused to emit light. When the light source 424 emits light, the light introduction region 306d on the side surface 306 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 306d. The introduced light is guided through the region 314, reaches the region 324, and is extracted from the light extraction surface 301 in the region 324.

For example, when light is to be extracted from the light extraction surface 301 in the region 331, the light source 431 is caused to emit light. When the light source 431 emits light, the light introduction region 304a of the side surface 304 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 304a. The introduced light is guided through the region 341, reaches the region 331, and is extracted from the light extraction surface 301 in the region 331.

For example, when light is to be extracted from the light extraction surface 301 in the region 332, the light source 432 is caused to emit light. When the light source 432 emits light, light is irradiated to the light introduction region 303c of the side surface 303, and light is introduced into the light guide plate 300 from the light introduction region 303c. The introduced light is guided through the region 331, reaches the region 332, and is extracted from the light extraction surface 301 in the region 332.

For example, when light is to be extracted from the light extraction surface 301 in the region 333, the light source 433 is caused to emit light. When the light source 433 emits light, the light introduction region 304c on the side surface 303 is irradiated with light, and the light is introduced into the light guide plate 300 from the light introduction region 304c. The introduced light is guided through the region 343, reaches the region 333, and is extracted from the light extraction surface 301 in the region 333.

For example, when light is to be extracted from the light extraction surface 301 in the region 334, the light source 434 is caused to emit light. When the light source 434 emits light, the light introduction region 305c on the side surface 305 is irradiated with light, and the light is introduced into the light guide plate 300 from the light introduction region 305c. The introduced light is extracted from the light extraction surface 301 in the region 334.

For example, when light is to be extracted from the light extraction surface 301 in the region 341, the light source 441 is caused to emit light. When the light source 441 emits light, the light introduction region 303d on the side surface 303 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 303d. The introduced light is extracted from the light extraction surface 301 in the region 341.

For example, when light is to be extracted from the light extraction surface 301 in the region 342, the light source 442 is caused to emit light. When the light source 442 emits light, the light introduction region 304b of the side surface 304 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 304b. The introduced light is extracted from the light extraction surface 301 in the region 342.

For example, when light is to be extracted from the light extraction surface 301 in the region 343, the light source 443 is caused to emit light. When the light source 443 emits light, the light introduction region 305d on the side surface 305 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 305d. The introduced light is guided through the region 344, reaches the region 343, and is extracted from the light extraction surface 301 in the region 343.

For example, when light is to be extracted from the light extraction surface 301 in the region 344, the light source 444 is caused to emit light. When the light source 444 emits light, the light introduction region 304d of the side surface 304 is irradiated with light, and light is introduced into the light guide plate 300 from the light introduction region 304d. The introduced light is extracted from the light extraction surface 301 in the region 344.

As described above, in the illuminating device 1 according to the first embodiment of the present invention, one or a group of light sources 411 to 414 and 421 is provided for one region 311 to 314, 321 to 324, 331 to 334, and 341 to 344. 424, 431 to 434, 441 to 444 are allocated, and the assigned areas 311 to 314 and 321 are simply adjusted by dimming the light source 411 to 414, 421 to 424, 431 to 434, and 441 to 444. Light can be selectively extracted from the light extraction surfaces 301 in ˜324, 331˜334, 341˜344. Since only one or a group of light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 is dimmed, the selective light extraction is easy. Further, since the assignment of the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 is simple, the configuration of the lighting device 1 can be simplified. Furthermore, the amount of light to be taken out can be easily adjusted by adjusting the brightness of light emission of the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444. In the illumination device 1 according to the present embodiment, local dimming can be easily realized because light can be selectively extracted from the light extraction surface 301 in the desired regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344. it can.

Although the first embodiment of the present invention has been described in detail above, the present invention may be further modified.
For example, regarding the shape of the light guide plate 300, the light extraction surface 301 and the back surface 302 do not necessarily have to be parallel.
For example, the shape of the main surface of the light guide plate 300 may not be rectangular.
For example, the thickness of the light guide plate 300 may be non-uniform as necessary.

For example, each of the side surfaces 303 to 306 which are light introduction surfaces may be a flat surface or an uneven surface having unevenness. In the case of an uneven surface, for example, unevenness such as a lens or a prism may be formed in order to increase the light introduction efficiency. By forming a lens, a prism, or the like, for example, the guided light can be converted into parallel light. By using parallel light, the diffusion of light can be prevented more stably, so that the phenomenon that light is guided to a region other than the desired region can be prevented stably. Further, by forming a lens, a prism, or the like, for example, the guided light can be intentionally diffused. It is preferable from the viewpoint of preventing eyeballs to diffuse the guided light to a predetermined degree. Here, the eyeball refers to a periodic light and dark pattern derived from the arrangement of the light sources, which occurs in the vicinity of the light introduction surface of the light extraction surface. When the light emission efficiency of the light source is improved, the installation interval of the light sources tends to be widened, and an eyeball tends to be generated near the light introduction surface.

For example, in the first embodiment described above, by forming a pattern on one or both of the light extraction surface 301 and the back surface 302 in the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344, the regions 311 to 314 are formed. , 321 to 324, 331 to 334, and 341 to 344 are anisotropic light extraction regions, but may be made anisotropic light extraction regions by other means.

For example, the direction of the virtual axis for each of the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344, and the light introduction region corresponding to each of the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 The positions of 303a to 303d, 304a to 304d, 305a to 305d, 306a to 306d and the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 may be further changed.

For example, you may provide a light-shielding part between adjacent areas as needed. Taking the first embodiment as an example, it is not necessary to guide light between the region 312 and the region 313, and therefore a light blocking portion may be provided.

For example, the entire region of the light guide plate may not be an anisotropic light extraction region. Therefore, in a part of the light guide plate, a region having a light extraction pattern for extracting light in any light guide direction on one or both of the light extraction surface and the back surface, so that light in any light guide direction is not extracted. A region where both the extraction surface and the back surface are smooth surfaces may be provided. However, at least a plurality of regions of the light guide are set as anisotropic light extraction regions.

Further, for example, the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 of the light guide plate 300 are preferably divided at equal intervals in both the X-axis direction and the Y-axis direction as in the above-described embodiment. , It does not have to be divided at equal intervals. When not divided at equal intervals, the area of the light extraction surface in each region is different. In that case, it is preferable to adjust the amount of light emitted from the light source corresponding to each region.

Further, the number of regions of the light guide plate and the number of rows and columns when dividing into a matrix are not limited to the numbers in the above-described embodiment. However, when the light guide plate is divided into a × b areas in a matrix of a rows and b columns (a and b are each an integer of 2 or more) when viewed from the light extraction direction, the numbers a and b described above are used. It is preferable that b satisfies 2a + 2b ≧ a × b. By applying the present invention when the light guide plate is divided into a large number of areas in this way, it is possible to add brightness and darkness independently for each area, and to demonstrate the advantages of the present invention with a simple structure. Can easily realize local dimming.

However, when the light guide plate is divided into a × b regions in a matrix of a rows and b columns as viewed from the light extraction direction as described above, more than half of the a × b regions are different. The isotropic light extraction region is preferable. By having anisotropy in the region from which light is extracted, a larger number of sections can be realized.

Further, it is preferable that at least one light introduction region corresponds to one region of the light guide plate. For this reason, it is preferable that the number of light introducing regions is equal to or greater than the number of regions of the light guide plate. When the number of light introduction regions is larger than the number of light guide plate regions, two or more light introduction regions may be assigned to one region of the light guide plate. However, in this case, it is preferable to synchronize the irradiation of light to a plurality of light introduction regions corresponding to the same region of the light guide plate.

In addition, the lighting device may include components other than the light source and the light guide plate. For example, an optical sheet may be provided.
If the example of an optical sheet is given, a condensing sheet will be mentioned. The condensing sheet is usually provided on the light extraction surface side of the light guide plate. The light extracted from the light extraction surface tends to have different light components for each region depending on the light guide direction in the light guide plate. That is, the extracted light includes light having a wide light emission angle in the X-axis direction and light having a wide light emission angle in the Y-axis direction, and both tend to be different for each region. Therefore, if a light collecting sheet is provided in the illumination device, the difference in the light output angle can be reduced by aligning the light output direction of the extracted light. Specific examples of such a light collecting sheet include UTE-1 (manufactured by Miraitech), BEF (manufactured by 3M), and the like. In addition, when using BEF as a condensing sheet | seat, it is preferable to overlap and use two BEFs so that the axis | shaft of a lens may orthogonally cross.

Examples of the optical sheet include a diffusion sheet. When a diffusion sheet is provided between the light guide plate and the light collecting sheet, moire can be hardly generated. In addition, if a diffusion sheet is provided on the side opposite to the light guide plate of the light collecting sheet, a sudden change in front luminance can be suppressed and the screen glare can be suppressed if the observation angle of the observer changes. it can.
In addition, when used as a backlight unit of a liquid crystal module, a recursive optical sheet having a polarization separation function may be provided for the purpose of improving the front luminance.
Further, in the lighting device, a reflection sheet such as a white reflection sheet may be provided on the back surface of the light guide plate.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 11 is a front view schematically showing a state in which the illumination device according to the second embodiment of the present invention is viewed from the light extraction surface side in the Z-axis direction. In FIG. 11, the same reference numerals as those in FIGS. 9 and 10 indicate the same elements as those in FIGS. 9 and 10. As shown in FIG. 11, the illumination device 2 according to the second embodiment of the present invention includes one light guide plate 300 and light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444.

In the illumination device 2 according to the second embodiment, the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 of the light guide plate 300 have different anisotropic directions, and the regions 311 to 314, 321 to 324 have different orientations. , 331 to 334, 341 to 344 and the light introduction regions 303a to 303d, 304a to 304d, 305a to 305d, and 306a to 306d, and the regions 311 to 314, 321 to 324, 331 to 334 , 341 to 344, except that the positions of the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 are the same as those of the lighting device 1 according to the first embodiment.

In the light guide plate 300 according to the second embodiment, one or both of the light extraction surface 301 and the back surface 302 in the

regions

312, 313, 323, 324, 331, 334, 341, 342 are guided in parallel with the X-axis direction. A pattern that functions as a light extraction pattern and functions as a light diffusion prevention pattern does not function as a light extraction pattern for light guided parallel to the Y-axis direction. . Accordingly, in the

regions

312, 313, 323, 324, 331, 334, 341, and 342, light guided in parallel to the X-axis direction is extracted from the light extraction surface 301 and guided in parallel to the Y-axis direction. Light is guided along the Y-axis direction without being extracted.

regions

311, 314, 321, 322, 333, 343, and 344 is light extraction for light guided parallel to the Y-axis direction. A pattern that functions as a pattern and does not function as a light extraction pattern for light guided parallel to the X-axis direction, but functions as a light diffusion prevention pattern is formed. Therefore, in the

regions

311, 314, 321, 322, 332, 333, 343, and 344, light guided in parallel to the Y-axis direction is extracted from the light extraction surface 301 and guided in parallel to the X-axis direction. Light is guided along the X-axis direction without being extracted.

Furthermore, in the lighting device 2 according to the second embodiment, the light introduction region 306a on the side surface 306 corresponds to the region 311 and the light source 411 is provided in front of the region 306a.
The light introduction region 303a on the side surface 303 corresponds to the region 312 and a light source 412 is provided in front of the region 303a.
The light introduction region 305a on the side surface 305 corresponds to the region 313, and a light source 413 is provided in front of the region 305a.
A light introduction region 306d on the side surface 306 corresponds to the region 314, and a light source 414 is provided in front of the region 306d.
A light introduction region 304a on the side surface 304 corresponds to the region 321 and a light source 421 is provided in front of the region 304a.
A light introduction region 306b on the side surface 306 corresponds to the region 322, and a light source 422 is provided in front of the region 306b.
A light introduction region 303b on the side surface 303 corresponds to the region 323, and a light source 423 is provided in front of the region 303b.
A light introduction region 305b on the side surface 305 corresponds to the region 324, and a light source 424 is provided in front of the region 305b.
The light introduction region 303c on the side surface 303 corresponds to the region 331, and a light source 431 is provided in front of the region 303c.
A light introduction region 304b on the side surface 303 corresponds to the region 332, and a light source 432 is provided in front of the region 304b.
A light introduction region 306c on the side surface 306 corresponds to the region 333, and a light source 433 is provided in front of the region 306c.
A light introduction region 305c on the side surface 305 corresponds to the region 334, and a light source 434 is provided in front of the region 305c.
The light introduction region 303d on the side surface 303 corresponds to the region 341, and a light source 441 is provided in front of the region 303d.
A light introduction region 305d on the side surface 305 corresponds to the region 342, and a light source 442 is provided in front of the region 305d.
The light introduction region 304c on the side surface 304 corresponds to the region 343, and a light source 443 is provided in front of the region 304c.
Further, the light introduction region 304d on the side surface 304 corresponds to the region 344, and a light source 444 is provided in front of the region 304d.

The lighting device 2 according to the second embodiment of the present invention is configured as described above. Therefore, in use, the light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 corresponding to the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344 from which light is to be extracted have a desired brightness. Select to emit light. Accordingly, in the same manner as the illumination device 1 according to the first embodiment, the corresponding regions 311 to 314, 321 to 324, and 331 from the emitted light sources 411 to 414, 421 to 424, 431 to 434, and 441 to 444 are provided. The light is guided to 334 to 341 to 344, and the light is extracted from the light extraction surfaces 301 in the regions 311 to 314, 321 to 324, 331 to 334, and 341 to 344.

As mentioned above, the illuminating device 2 which concerns on 2nd embodiment of this invention can be used similarly to the illuminating device 1 which concerns on 1st embodiment, and the same advantage is acquired.
Moreover, you may change and implement the illuminating device 2 which concerns on 2nd embodiment of this invention similarly to the illuminating device 1 which concerns on 1st embodiment.

By the way, in the light guide plate 300 according to the second embodiment, there are places where anisotropic light extraction regions where the directions of the virtual axes are parallel are adjacent to each other. For example, the region 332 and the region 333 of the light guide plate 300 are adjacent to each other, and the direction of the imaginary axis is parallel to the Y-axis direction. In this case, when the full width at half maximum of the light source 432 corresponding to the region 332 is wide, part of the light that should be extracted from the light extraction surface 301 in the region 332 is also guided to the region 333, and the light extraction surface 301 in the region 333 is obtained. There is a possibility that light will be extracted from. Such a phenomenon is called light leakage. In order to prevent the light leakage, it is preferable to take the following measures, for example. That is, for example, it is preferable to provide a condensing member such as a lens in the region 304b of the side surface 304 corresponding to the region 332 so that the light introduced from the region 304b which is a light introduction region is close to parallel light. In addition, for example, it is preferable to attach a lens or the like to the light source 432 so that the light emitted from the light source 432 approaches parallel light. Further, for example, a light shielding portion may be provided between the region 332 and the region 333.

[Third embodiment]
The third embodiment of the present invention will be described below with reference to the drawings. FIG. 12 is a front view schematically showing a state in which the illumination device according to the third embodiment of the present invention is viewed from the light extraction surface side in the Z-axis direction. In FIG. 12, the same reference numerals as those in FIGS. 9 to 11 denote the same elements as in FIGS. As shown in FIG. 12, the illumination device 3 according to the third embodiment of the present invention includes one light guide plate 300 and light sources 411 to 416, 421 to 426, and 431 to 436.

In the illumination device 3 according to the third embodiment, the light guide plate 300 has three rows in the X-axis direction in which the size in the X-axis direction of the light guide plate 300 is longer than the size in the Y-axis direction. , Divided in six rows in the Y-axis direction at equal intervals, the anisotropic directions in the regions 311 to 316, 321 to 326, 331 to 336 of the light guide plate 300 are different, and the regions 311 to 316, 321 to 326 , 331 to 336 and the light introduction regions 303a to 303c, 304a to 304f, 305a to 305c, and 306a to 306f, and the light sources corresponding to the regions 311 to 316, 321 to 326, 331 to 336 Except that the positions of 411 to 416, 421 to 426, and 431 to 436 are different, it is the same as the illumination device 1 according to the first embodiment.

In the light guide plate 300 according to the third embodiment, one or both of the light extraction surface 301 and the back surface 302 in the

regions

312, 314, 321, 326, 333 and 335 are guided by light guided in parallel in the X-axis direction. On the other hand, a pattern that functions as a light extraction pattern and does not function as a light extraction pattern for light guided parallel to the Y-axis direction, but functions as a light diffusion prevention pattern. Accordingly, in the

regions

312, 314, 321, 326, 333, and 335, light guided in parallel to the X-axis direction is extracted from the light extraction surface 301, and light guided in parallel to the Y-axis direction is not extracted. The light is guided along the Y-axis direction.

regions

311, 313, 315, 316, 322, 323, 324, 325, 331, 332, 334, 336 are guided in parallel with the Y-axis direction. A pattern that functions as a light extraction pattern and functions as a light diffusion prevention pattern without functioning as a light extraction pattern for light guided parallel to the X-axis direction is formed. Therefore, in the

regions

311, 313, 315, 316, 322, 323, 324, 325, 331, 332, 334, and 336, the light guided in parallel to the Y-axis direction is extracted from the light extraction surface 301, and the X-axis Light guided in parallel to the direction is guided along the X-axis direction without being extracted.

In the illumination device 3 according to the present embodiment, light is extracted from the light extraction surfaces 301 in all the regions 311 to 316, 321 to 326, and 331 to 336 of the light guide plate 300. Therefore, as shown in FIG. 12, the side surfaces 303 to 306 which are light introduction surfaces of the light guide plate 300 have at least one location corresponding to each of the regions 311 to 316, 321 to 326 and 331 to 336 where light is to be extracted. There are light introduction regions provided one by one.

Specifically, the light introduction regions 303a to 303c are formed by dividing the side surface 303 at equal intervals in the Y-axis direction. As shown in FIG. 12, the light introduction region 303a is a region located on the left side of the region 311 in the drawing, the light introduction region 303b is a region located on the left side of the region 321 in the drawing, and the light introduction region 303c is a region 331. This is an area located on the left side of FIG.

Further, the light introduction regions 304a to 304f are formed by dividing the side surface 304 at equal intervals in the X-axis direction. As shown in FIG. 12, the light introduction region 304a is a region located below the region 331 in the drawing, the light introduction region 304b is a region located below the region 332 in the drawing, and the light introduction region 304c is The region 333 is a region located on the lower side in the drawing, the light introduction region 304d is a region located on the lower side of the region 334 in the drawing, and the light introduction region 304e is a region located on the lower side of the region 335 in the drawing. The light introduction region 304f is a region located below the region 336 in the drawing.

Further, the light introduction regions 305a to 305c are formed by dividing the side surface 305 at equal intervals in the Y-axis direction. 12, the light introduction region 305a is a region located on the right side of the region 316 in the drawing, the light introduction region 305b is a region located on the right side of the region 326 in the drawing, and the light introduction region 305c is a region 336. It is the area | region located in the right side in the figure. Therefore, the light introduction regions 305a to 305c are located on the opposite sides of the light introduction regions 303a to 303c, respectively.

Furthermore, the light introduction regions 306a to 306f are formed by dividing the side surface 306 at equal intervals in the X-axis direction. As shown in FIG. 12, the light introduction region 306a is a region located on the upper side of the region 311 in the drawing, the light introduction region 306b is a region located on the upper side of the region 312 in the drawing, and the light introduction region 306c is the region 313. The light introduction region 306d is a region located above the region 314 in the figure, and the light introduction region 306e is a region located above the region 315 in the figure, and the light introduction region. Reference numeral 306f denotes an area located above the area 316 in the drawing. Accordingly, the light introduction regions 306a to 306f are located on the opposite sides of the light introduction regions 304a to 304f, respectively.

Furthermore, in the illumination device 3 according to the third embodiment, the light introduction region 306a on the side surface 306 corresponds to the region 311 and the light source 411 is provided in front of the region 306a.
The light introduction region 303a on the side surface 303 corresponds to the region 312 and a light source 412 is provided in front of the region 303a.
A light introduction region 306c on the side surface 306 corresponds to the region 313, and a light source 413 is provided in front of the region 306c.
A light introduction region 305a on the side surface 305 corresponds to the region 314, and a light source 414 is provided in front of the region 305a.
A light introduction region 306e on the side surface 306 corresponds to the region 315, and a light source 415 is provided in front of the region 306e.
A light introduction region 306f on the side surface 306 corresponds to the region 316, and a light source 416 is provided in front of the region 306f.
A light introduction region 303b on the side surface 303 corresponds to the region 321 and a light source 421 is provided in front of the region 303b.
A light introduction region 306b on the side surface 306 corresponds to the region 322, and a light source 422 is provided in front of the region 306b.
A light introduction region 304c on the side surface 304 corresponds to the region 323, and a light source 423 is provided in front of the region 304c.
A light introduction region 306d on the side surface 306 corresponds to the region 324, and a light source 424 is provided in front of the region 306d.
A light introduction region 304e on the side surface 304 corresponds to the region 325, and a light source 425 is provided in front of the region 304e.
A light introduction region 305b on the side surface 305 corresponds to the region 326, and a light source 426 is provided in front of the region 305b.
A light introduction region 304a on the side surface 304 corresponds to the region 331, and a light source 431 is provided in front of the region 304a.
The light introduction region 304b on the side surface 304 corresponds to the region 332, and a light source 432 is provided in front of the region 304b.
The light introduction region 303c on the side surface 303 corresponds to the region 333, and a light source 433 is provided in front of the region 303c.
A light introduction region 304d on the side surface 304 corresponds to the region 334, and a light source 434 is provided in front of the region 304d.
A light introduction region 305c on the side surface 305 corresponds to the region 335, and a light source 435 is provided in front of the region 305c.
Further, the light introduction region 304f on the side surface 304 corresponds to the region 336, and a light source 436 is provided in front of the region 304f.

The lighting device 3 according to the third embodiment of the present invention is configured as described above. Accordingly, in use, the light sources 411 to 416, 421 to 426, and 431 to 436 corresponding to the regions 311 to 316, 321 to 326, and 331 to 336 from which light is to be extracted are selectively emitted with desired brightness. As a result, in the same manner as the illumination device 1 according to the first embodiment, the emitted light sources 411 to 416, 421 to 426, 431 to 436 are changed to the corresponding regions 311 to 316, 321 to 326, 331 to 336. Light is guided, and light is extracted from the light extraction surface 301 in the regions 311 to 316, 321 to 326, and 331 to 336.

As mentioned above, the illuminating device 3 which concerns on 3rd embodiment of this invention can be used similarly to the illuminating devices 1 and 2 which concern on 1st embodiment and 2nd embodiment, and the same advantage is acquired.
Moreover, you may change and implement the illuminating device 3 which concerns on 3rd embodiment of this invention similarly to the illuminating devices 1 and 2 which concern on 1st embodiment and 2nd embodiment.

[Fourth embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 13 is a perspective view schematically showing an illumination apparatus according to the fourth embodiment of the present invention. FIG. 14 is an exploded perspective view schematically showing an exploded state of the illumination device according to the fourth embodiment of the present invention. As shown in FIG. 13, the illuminating device 4 according to the fourth embodiment of the present invention includes a multi-layer light guide plate 700 in which two

light guide plates

500 and 600 having the same size are stacked, and light sources 812 to 816, 821. , 824, 825, 836, 911, 922, 923, 926, 931 to 935.

The multilayer light guide plate 700 is a member in which the light guide plate 500 and the light guide plate 600 are stacked. As shown in FIG. 14, each of the light guide plate 500 and the light guide plate 600 has a rectangular plate shape.
The light guide plate 500 has a light extraction surface 501 and a back surface 502 located on the opposite side of the light extraction surface 501 as its main surface. The light guide plate 500 has four side surfaces 503 to 506 at the ends of the light extraction surface 501 and the back surface 502, of which the side surfaces 503 and 506 are used as light introduction surfaces.
On the other hand, the light guide plate 600 has a light extraction surface 601 and a back surface 602 located on the opposite side of the light extraction surface 601 as its main surface. The light guide plate 600 has four side surfaces 603 to 606 at the ends of the light extraction surface 601 and the back surface 602, and the side surfaces 603 and 606 are used as light introduction surfaces.
The light guide plate 500 and the light guide plate 600 are stacked such that the back surface 502 of the light guide plate 500 and the light extraction surface 601 of the light guide plate 600 face each other, thereby forming a multilayer light guide plate 700.

Here, the thickness direction of the multilayer light guide plate 700 is defined as the Z-axis direction. Of the directions parallel to the plane perpendicular to the Z-axis direction, the direction parallel to one side of the rectangle of the light extraction surface 501 is defined as the X-axis direction, and the direction perpendicular to the X-axis direction is defined as the Y-axis direction. The light extraction surface 501 and the back surface 502 of the light guide plate 500 and the light extraction surface 601 and the back surface 602 of the light guide plate 600 are all surfaces perpendicular to the Z-axis direction. Further, the side surface 503 and the side surface 505 of the light guide plate 500 and the side surface 603 and the side surface 605 of the light guide plate 600 are surfaces perpendicular to the X-axis direction, and the side surface 504 and the side surface 506 of the light guide plate 500 and the side surface 604 and the side surface of the light guide plate 600. Reference numeral 606 denotes a plane perpendicular to the Y-axis direction. Furthermore, it is assumed that the light extraction direction from the light extraction surface 501 and the light extraction surface 601 is parallel to the Z-axis direction.

The light guide plate 500 and the light guide plate 600 are each divided into 18 regions in a matrix of 3 rows and 6 columns as viewed from the light extraction direction (in FIG. 14, the light extraction surface side in the Z-axis direction). . Specifically, as shown in FIG. 14, it is divided into three rows at equal intervals in the X-axis direction, and is divided into six columns at equal intervals in the Y-axis direction. Thus, the light guide plate 500 has regions 511 to 516, 521 to 526, and 531 to 536 in three rows in the X-axis direction and six columns in the Y-axis direction. The light guide plate 600 has regions 611 to 616, 621 to 626, and 631 to 636 in three rows in the X-axis direction and six columns in the Y-axis direction.
However, the regions 511 to 516, 521 to 526, 531 to 536 and the regions 611 to 616, 621 to 626, and 631 to 636 are set to control the position where light is extracted. It does not have to be physically separated by disconnection or the like.

FIG. 15 shows the light guide plate 500 and the light source for irradiating light on the side surfaces 503 and 506 of the light guide plate 500 as viewed from the light extraction surface side in the Z-axis direction in the illumination device 4 according to the fourth embodiment of the present invention. FIG. In FIG. 15, the same reference numerals as those in FIGS. 13 and 14 denote the same elements as those in FIGS. As shown in FIG. 15, among the divided areas 511 to 516, 521 to 526, and 531 to 536, the areas 512 to 516, 521 to 525, and 531 to 536 are all anisotropic light extraction areas. Then, the positions of the

regions

514, 524, 525, and 536, which are anisotropic light extraction regions, are compared with other anisotropic light extraction regions in which light introduced from the corresponding light introduction regions into the light guide plate 500 has different virtual axis directions. The position is adjusted so as to reach the

regions

514, 524, 525, and 536 after being guided through. From another point of view, the positions of the

regions

514, 524, 525, and 536, which are anisotropic light extraction regions, indicate that the light introduced into the light guide plate 500 from the corresponding light introduction region is parallel to the direction of the virtual axis. The position is adjusted so as to reach the

region

514, 524, 525, 536 without passing through the anisotropic light extraction region.

Specifically, one or both of the light extraction surface 501 and the back surface 502 in the

regions

514, 525, and 536 of the light guide plate 500 function as a light extraction pattern for light guided parallel to the X-axis direction. However, the light guided parallel to the Y-axis direction does not function as a light extraction pattern, but a pattern that functions as a light diffusion prevention pattern is formed. Therefore, in the

regions

514, 525, and 536, the light guided in parallel to the X-axis direction is extracted from the light extraction surface 501, and the light guided in parallel to the Y-axis direction is not extracted and is along the Y-axis direction. The light is guided.

Further, one or both of the light extraction surface 501 and the back surface 502 in the

regions

512, 513, 515, 516, 521 to 524, 531 to 535 of the light guide plate 500 is directed to the light guided in parallel in the Y-axis direction. In this case, a pattern that functions as a light extraction pattern and does not function as a light extraction pattern for light guided parallel to the X-axis direction is formed. Therefore, in the

regions

512, 513, 515, 516, 521 to 524, 531 to 535, light guided in parallel to the Y-axis direction is extracted from the light extraction surface 501 and guided in parallel to the X-axis direction. Light is guided along the X-axis direction without being extracted.

Further, the region 511 and the region 526 are regions where both the light extraction surface 501 and the back surface 502 are smooth planes. In these

regions

511 and 526, neither the light guided in parallel to the X-axis direction nor the light guided in parallel to the Y-axis direction is extracted from the light extraction surface 501, and the X-axis direction and the Y-axis direction respectively. The light is guided along.

Further, in the regions 511 to 516, 521 to 526, and 531 to 536 of the light guide plate 500, when light is irradiated to the back surface 502 along the Z-axis direction, the irradiated light is the regions 511 to 516, 521 to 526. , 531 to 536 and extracted from the light extraction surface 501.

In the light guide plate 500 of the illuminating device 4 according to the present embodiment, the light introduced from the side surfaces 503 and 506 that are the light introduction surfaces of the light guide plate 500 is used as partial regions 512 to 516, 521, and 524 of the light guide plate 500. The light is extracted from the light extraction surface 501 at 525 and 536. Therefore, as shown in FIG. 15, the side surfaces 503 and 506 have at least one light introduction region corresponding to each of the regions 512 to 516, 521, 524, 525 and 536 from which light is to be extracted. .

Specifically, the light introduction regions 503a to 503c are formed by dividing the side surface 503 at equal intervals in the Y-axis direction. As shown in FIG. 15, the light introduction region 503a is a region located on the left side of the region 511 in the drawing, the light introduction region 503b is a region located on the left side of the region 521 in the drawing, and the light introduction region 503c is a region 531. This is an area located on the left side of FIG.

Further, the light introduction regions 506a to 506f are formed by dividing the side surface 506 at equal intervals in the X-axis direction. As shown in FIG. 15, the light introduction region 506 a is a region located on the upper side of the region 511 in the drawing, the light introduction region 506 b is a region located on the upper side of the region 512 in the drawing, and the light introduction region 506 c is the region 513. The light introduction region 506d is a region located above the region 514 in the drawing, and the light introduction region 506e is a region located above the region 515 in the figure, and the light introduction region. Reference numeral 506f denotes an area located above the area 516 in the drawing.

FIG. 16 shows the light guide plate 600 and the light source that irradiates light to the side surfaces 603 and 606 of the light guide plate 600 as viewed from the light extraction surface side in the Z-axis direction in the illumination device 4 according to the fourth embodiment of the present invention. FIG. In FIG. 16, the same reference numerals as those in FIGS. 13 to 15 denote the same elements as those in FIGS. As shown in FIG. 16, among the divided regions 611 to 616, 621 to 626 and 631 to 636, the regions 611 to 616, 622 to 626 and 631 to 635 are all anisotropic light extraction regions. Then, the positions of the

regions

623, 626, 631 to 635, which are anisotropic light extraction regions, are compared with other anisotropic light extraction regions in which light introduced from the corresponding light introduction regions into the light guide plate 500 has different virtual axis directions. The position is adjusted so as to reach the

regions

623, 626, 631 to 635 after being guided through. From another point of view, the positions of the

regions

623, 626, 631 to 635 which are anisotropic light extraction regions are set so that the light introduced into the light guide plate 500 from the corresponding light introduction region is parallel to the direction of the virtual axis. The position is adjusted so as to reach the

regions

623, 626, 631 to 635 without passing through the anisotropic light extraction region.

Specifically, one or both of the light extraction surface 601 and the back surface 602 in the regions 611 to 616, 622, 624, 625, and 633 of the light guide plate 600 is directed to the light guided in parallel in the X-axis direction. Functions as a light extraction pattern, and does not function as a light extraction pattern for light guided in parallel to the Y-axis direction, but forms a pattern that functions as a light diffusion prevention pattern. Therefore, in the regions 611 to 616, 622, 624, 625, and 633, light guided in parallel to the X-axis direction is extracted from the light extraction surface 601 and light guided in parallel to the Y-axis direction is not extracted. The light is guided along the Y-axis direction.

Further, one or both of the light extraction surface 601 and the back surface 602 in the

regions

623, 626, 631, 632, 634, and 635 of the light guide plate 600 is light extraction for light guided parallel to the Y-axis direction. A pattern that functions as a pattern and does not function as a light extraction pattern for light guided parallel to the X-axis direction, but functions as a light diffusion prevention pattern is formed. Therefore, in the

regions

623, 626, 631, 632, 634, and 635, light guided in parallel to the Y-axis direction is extracted from the light extraction surface 601, and light guided in parallel to the X-axis direction is not extracted. The light is guided along the X-axis direction.

Furthermore, the region 621 and the region 636 are regions in which both the light extraction surface 601 and the back surface 602 are smooth planes. In these

areas

621 and 636, neither the light guided in parallel to the X-axis direction nor the light guided in parallel to the Y-axis direction is extracted from the light extraction surface 601, and the X-axis direction and the Y-axis direction respectively. The light is guided along.

In the light guide plate 600 of the illuminating device 4 according to the present embodiment, the light introduced from the side surfaces 603 and 606 that are the light introduction surfaces of the light guide plate 600 is used as part of the

regions

611, 622, 623, 626 of the light guide plate 600. The light is extracted from the light extraction surface 501 at 631 to 635. Therefore, as shown in FIG. 16, the side surfaces 603 and 606 have at least one light introduction region corresponding to each of the

regions

611, 622, 623, 626, 631 to 635 from which light is to be extracted. .

Specifically, the light introduction regions 603a to 603c are formed by dividing the side surface 603 at equal intervals in the Y-axis direction. 16, the light introduction region 603a is a region located on the left side of the region 611 in the drawing, the light introduction region 603b is a region located on the left side of the region 621 in the drawing, and the light introduction region 603c is a region 631. This is an area located on the left side of FIG.

Further, the light introduction regions 606a to 606f are formed by dividing the side surface 606 at equal intervals in the X-axis direction. As illustrated in FIG. 16, the light introduction region 606 a is a region located on the upper side of the region 611 in the drawing, the light introduction region 606 b is a region located on the upper side of the region 612 in the drawing, and the light introduction region 606 c is the region 613. The light introduction region 606d is a region located above the region 614 in the figure, and the light introduction region 606e is a region located above the region 615 in the figure, and is a light introduction region. Reference numeral 606f denotes an area located above the area 616 in the drawing.

The light introduction regions 503a to 503c and 506a to 506f of the light guide plate 500 and the light introduction regions 603a to 603c and 606a to 606f of the light guide plate 600 are set for controlling the light emission position of the illumination device 4. Yes, usually not physically separated by boundaries.

The light sources 812 to 816, 821, 824, 825, and 836 shown in FIG. 15 are devices that irradiate light to the side surfaces 503 and 506 that are light introduction surfaces of the light guide plate 500. From the viewpoint of realizing local dimming, the light sources 812 to 816, 821, 824, 825 and 836 are provided so that the light introduction regions 503 a to 503 c and 506 a to 506 f can be irradiated with light independently. As a result, the light sources 812 to 816, 821, 824, 825, and 836 can be dimmed for each of the light extraction regions 512 to 516, 521, 524, 525, and 536.

Specifically, the light introduction region 506b on the side surface 506 corresponds to the region 512, and a light source 812 is provided in front of the region 506b.
A light introduction region 506c on the side surface 506 corresponds to the region 513, and a light source 813 is provided in front of the region 506c.
A light introduction region 503a on the side surface 503 corresponds to the region 514, and a light source 814 is provided in front of the region 503a.
A light introduction region 506e on the side surface 506 corresponds to the region 515, and a light source 815 is provided in front of the region 506e.
A light introduction region 506f on the side surface 506 corresponds to the region 516, and a light source 816 is provided in front of the region 506f.
A light introduction region 506a on the side surface 506 corresponds to the region 521, and a light source 821 is provided in front of the region 506a.
A light introduction region 506d on the side surface 506 corresponds to the region 524, and a light source 824 is provided in front of the region 506d.
A light introduction region 503b on the side surface 503 corresponds to the region 525, and a light source 825 is provided in front of the region 503b.
Further, the light introduction region 503c on the side surface 503 corresponds to the region 536, and a light source 836 is provided in front of the region 503c.

16 are devices that irradiate light to the side surfaces 603 and 606 which are light introduction surfaces of the light guide plate 600. The

light sources

911, 922, 923, 926, and 931 to 935 shown in FIG. From the viewpoint of realizing local dimming, the

light sources

911, 922, 923, 926, 931 to 935 are provided so as to be able to irradiate light independently to the light introduction regions 603a to 603c and 606a to 606f. Thus, the

light sources

911, 922, 923, 926, 931 to 935 can be dimmed for each of the

regions

611, 622, 623, 626, 631 to 635 from which light is extracted.

Specifically, the light introduction region 603a on the side surface 603 corresponds to the region 611, and a light source 911 is provided in front of the region 603a.
A light introduction region 603b on the side surface 603 corresponds to the region 622, and a light source 922 is provided in front of the region 603b.
A light introduction region 606c on the side surface 606 corresponds to the region 623, and a light source 923 is provided in front of the region 606c.
A light introduction region 606f on the side surface 606 corresponds to the region 626, and a light source 926 is provided in front of the region 606f.
A light introduction region 606a on the side surface 606 corresponds to the region 631, and a light source 931 is provided in front of the region 606a.
A light introduction region 606b on the side surface 606 corresponds to the region 632, and a light source 932 is provided in front of the region 606b.
A light introduction region 603c on the side surface 603 corresponds to the region 633, and a light source 933 is provided in front of the region 603c.
A light introduction region 606d on the side surface 606 corresponds to the region 634, and a light source 934 is provided in front of the region 606d.
Further, the light introduction region 606e on the side surface 606 corresponds to the region 635, and a light source 935 is provided in front of the region 606e.

The lighting device 4 according to the fourth embodiment of the present invention is configured as described above. In the illumination device 4 as described above, the light extraction surface 501 of the light guide plate 500 functions as the light extraction surface of the multilayer light guide plate 700. Accordingly, in use, the light sources 812 to 816, 821, 824, 825, and 836 and the

light sources

911, 922, 923, 926, and 931 to 935 are provided for each of the regions 511 to 516, 521 to 526, and 531 to 536 from which light is to be extracted. Selectively emit light at a desired brightness.

For example, when light is to be extracted from the light extraction surface 501 in the region 511, the light source 911 is caused to emit light. When the light source 911 emits light, light is irradiated to the light introduction region 603a of the side surface 603 of the light guide plate 600, and light is introduced into the light guide plate 600 from the light introduction region 603a. The introduced light is extracted from the light extraction surface 601 in the region 611 of the light guide plate 600. The extracted light is applied to the back surface 502 of the region 511 of the light guide plate 500, passes through the region 511, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 512, the light source 812 is caused to emit light. When the light source 812 emits light, light is irradiated to the light introduction region 506b on the side surface 506 of the light guide plate 500, and light is introduced into the light guide plate 500 from the light introduction region 506b. The introduced light is extracted from the light extraction surface 501 in the region 512 of the light guide plate 500.

For example, when light is to be extracted from the light extraction surface 501 in the region 513, the light source 813 is caused to emit light. When the light source 813 emits light, light is irradiated to the light introduction region 506c on the side surface 506 of the light guide plate 500, and light is introduced into the light guide plate 500 from the light introduction region 506c. The introduced light is extracted from the light extraction surface 601 in the region 513 of the light guide plate 500.

For example, when light is to be extracted from the light extraction surface 501 in the region 514, the light source 814 is caused to emit light. When the light source 814 emits light, light is irradiated to the light introduction region 503a on the side surface 503 of the light guide plate 500, and light is introduced into the light guide plate 500 from the light introduction region 503a. The introduced light is guided through the regions 511 to 513 of the light guide plate 500, reaches the region 514, and is extracted from the light extraction surface 501 in the region 514.

For example, when light is to be extracted from the light extraction surface 501 in the region 515, the light source 815 is caused to emit light. When the light source 815 emits light, light is irradiated to the light introduction region 506e on the side surface 506 of the light guide plate 500, and light is introduced into the light guide plate 500 from the light introduction region 506e. The introduced light is extracted from the light extraction surface 501 in the region 515 of the light guide plate 500.

For example, when light is to be extracted from the light extraction surface 501 in the region 516, the light source 816 is caused to emit light. When the light source 816 emits light, light is irradiated to the light introduction region 506f on the side surface 506 of the light guide plate 500, and light is introduced into the light guide plate 500 from the light introduction region 506f. The introduced light is extracted from the light extraction surface 501 in the region 516 of the light guide plate 500.

For example, when light is to be extracted from the light extraction surface 501 in the region 521, the light source 821 is caused to emit light. When the light source 821 emits light, light is irradiated to the light introduction region 506a on the side surface 506 of the light guide plate 500, and light is introduced into the light guide plate 500 from the light introduction region 506a. The introduced light is guided through the region 511 of the light guide plate 500, reaches the region 521, and is extracted from the light extraction surface 501 in the region 521.

For example, when light is to be extracted from the light extraction surface 501 in the region 522, the light source 922 is caused to emit light. When the light source 922 emits light, light is applied to the light introduction region 603b of the side surface 603 of the light guide plate 600, and light is introduced into the light guide plate 600 from the light introduction region 603b. The introduced light is guided through the region 621 of the light guide plate 600, reaches the region 622, and is extracted from the light extraction surface 601 in the region 622. The extracted light is applied to the back surface 502 of the region 522 of the light guide plate 500, passes through the region 522, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 523, the light source 923 is caused to emit light. When the light source 923 emits light, light is applied to the light introduction region 606c on the side surface 606 of the light guide plate 600, and light is introduced into the light guide plate 600 from the light introduction region 606c. The introduced light is guided through the region 613 of the light guide plate 600, reaches the region 623, and is extracted from the light extraction surface 601 in the region 623. The extracted light is applied to the back surface 502 of the region 523 of the light guide plate 500, passes through the region 523, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 524, the light source 824 is caused to emit light. When the light source 824 emits light, light is irradiated to the light introduction region 506d of the side surface 506 of the light guide plate 500, and light is introduced into the light guide plate 600 from the light introduction region 506d. The introduced light is guided through the region 514 of the light guide plate 500, reaches the region 524, and is extracted from the light extraction surface 501 in the region 524.

For example, when light is to be extracted from the light extraction surface 501 in the region 525, the light source 825 is caused to emit light. When the light source 825 emits light, the light introduction region 503b on the side surface 503 of the light guide plate 500 is irradiated with light, and the light is introduced into the light guide plate 500 from the light introduction region 503b. The introduced light is guided through the regions 521 to 524 of the light guide plate 500, reaches the region 525, and is extracted from the light extraction surface 501 in the region 525.

For example, when light is to be extracted from the light extraction surface 501 in the region 526, the light source 926 is caused to emit light. When the light source 926 emits light, the light introduction region 606f of the side surface 606 of the light guide plate 600 is irradiated with light, and the light is introduced into the light guide plate 600 from the light introduction region 606f. The introduced light is guided through the region 616 of the light guide plate 600, reaches the region 626, and is extracted from the light extraction surface 601 in the region 626. The extracted light is applied to the back surface 502 of the region 526 of the light guide plate 500, passes through the region 526, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 531, the light source 931 is caused to emit light. When the light source 931 emits light, the light introduction region 606a on the side surface 606 of the light guide plate 600 is irradiated with light, and the light is introduced into the light guide plate 600 from the light introduction region 606a. The introduced light is guided through the region 611 and the region 621 of the light guide plate 600, then reaches the region 631, and is extracted from the light extraction surface 601 in the region 631. The extracted light is applied to the back surface 502 of the region 531 of the light guide plate 500, passes through the region 531, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 532, the light source 932 is caused to emit light. When the light source 932 emits light, the light introduction region 606b on the side surface 606 of the light guide plate 600 is irradiated with light, and the light is introduced into the light guide plate 600 from the light introduction region 606b. The introduced light is guided through the region 612 and the region 622 of the light guide plate 600, then reaches the region 632, and is extracted from the light extraction surface 601 in the region 632. The extracted light is applied to the back surface 502 of the region 532 of the light guide plate 500, passes through the region 532, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 533, the light source 933 is caused to emit light. When the light source 933 emits light, the light introduction region 603c on the side surface 603 of the light guide plate 600 is irradiated with light, and the light is introduced into the light guide plate 600 from the light introduction region 603c. The introduced light is guided through the region 631 and the region 632 of the light guide plate 600, then reaches the region 633, and is extracted from the light extraction surface 601 in the region 633. The extracted light is applied to the back surface 502 of the region 533 of the light guide plate 500, passes through the region 533, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 534, the light source 934 is caused to emit light. When the light source 934 emits light, the light introduction region 606d on the side surface 606 of the light guide plate 600 is irradiated with light, and the light is introduced into the light guide plate 600 from the light introduction region 606d. The introduced light is guided through the region 614 and the region 624 of the light guide plate 600, reaches the region 634, and is extracted from the light extraction surface 601 in the region 634. The extracted light is applied to the back surface 502 of the region 534 of the light guide plate 500, passes through the region 534, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 535, the light source 935 is caused to emit light. When the light source 935 emits light, the light introduction region 606e on the side surface 606 of the light guide plate 600 is irradiated with light, and the light is introduced into the light guide plate 600 from the light introduction region 606e. The introduced light is guided through the region 615 and the region 625 of the light guide plate 600, then reaches the region 635, and is extracted from the light extraction surface 601 in the region 635. The extracted light is applied to the back surface 502 of the region 535 of the light guide plate 500, passes through the region 535, and is extracted from the light extraction surface 501.

For example, when light is to be extracted from the light extraction surface 501 in the region 536, the light source 836 is caused to emit light. When the light source 836 emits light, the light introduction region 503c on the side surface 503 of the light guide plate 500 is irradiated with light, and the light is introduced into the light guide plate 500 from the light introduction region 503c. The introduced light is guided through the regions 531 to 535 of the light guide plate 500, reaches the region 536, and is extracted from the light extraction surface 501 in the region 536.

As described above, the illumination device 4 according to the fourth embodiment of the present invention can also easily realize local dimming with a simple configuration as in the first to third embodiments. Further, the same advantages as those of the lighting device 1 according to the first to third embodiments can be obtained.
Furthermore, the illuminating device 4 according to the fourth embodiment of the present invention may be modified and implemented in the same manner as the illuminating device 1 according to the first to third embodiments.

In the fourth embodiment described above, the two light guide plates 500 and the light guide plate 600 are stacked. However, for example, three or more light guide plates may be stacked.
Further, for example, the size and shape of the overlapping light guide plates are usually the same, but may be different.

The number of superimposed light guide plates is n (n is an integer of 2 or more), and the overlapped light guide plates are a rows and b columns (a and b are integers of 2 or more, respectively) when viewed from the light extraction direction. .)) Is preferably divided into a × b regions, preferably 2 × n × a + 2 × n × b ≧ a × b. By applying the present invention when the light guide plate is divided into a large number of areas in this way, it is possible to add brightness and darkness independently for each area, and to demonstrate the advantages of the present invention with a simple structure. Can easily realize local dimming.

Further, an optical sheet or the like may be provided between the overlapped light guide plates.

[Fifth embodiment]
Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 17 is a perspective view schematically showing an illumination apparatus according to the fifth embodiment of the present invention. In FIG. 17, the same reference numerals as those in FIGS. 13 to 16 denote the same elements as those in FIGS. As shown in FIG. 17, the lighting device 5 according to the fifth embodiment of the present invention is a combination of four lighting devices that can extract light from each region in the same manner as the lighting device 4 according to the fourth embodiment. Have a configuration.

That is, when the illuminating device 5 is equally cut along a plane perpendicular to the X-axis direction and a plane perpendicular to the Y-axis direction, the portions 5A to 5D of the cut illuminating device 5 are respectively the fourth embodiment of the present invention. The light can be extracted from the light extraction surface 501 in each region in the same manner as the illumination device 4 according to the embodiment. For example, in the portion 5A of the illuminating device 5, light can be extracted for each of the regions 511 to 516, 521 to 526, and 531 to 536 by dimming the corresponding light source. Note that the portions 5A to 5D of the illumination device 5 are usually plane-symmetric with respect to the plane that cuts the illumination device 5.

Therefore, the illumination device 5 according to the fifth embodiment of the present invention can also easily implement local dimming with a simple configuration as in the first to fourth embodiments. Further, the same advantages as those of the lighting device 1 according to the first to fourth embodiments can be obtained. Furthermore, according to the illuminating device according to the fifth embodiment of the present invention, it is possible to realize the illuminating device 5 capable of dimming independently in each of a large number of areas of 72 locations of 6 divisions × 12 divisions. More precise local dimming is possible.

Further, the illumination device 5 according to the fifth embodiment of the present invention may be modified and implemented in the same manner as the illumination devices 1 to 4 according to the first to fourth embodiments. Further, for example, in the multilayer light guide plate 700 according to the fifth embodiment, the multilayer light guide plate 700 may be formed separately for each of the portions 5A to 5D of the lighting device 5, or may be formed integrally. .

[Light guide plate materials and manufacturing method]
Hereinafter, the material and manufacturing method of the light guide plate will be described.
Examples of the material of the light guide plate include glass and transparent resin. In addition, the material of a light-guide plate may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

Examples of the transparent resin include propylene-ethylene copolymer, polystyrene (PS), (meth) acrylic ester-aromatic vinyl compound copolymer, polyethylene terephthalate, terephthalic acid-ethylene glycol-cyclohexanedimethanol copolymer. Examples thereof include a coalescence, a polycarbonate, a methacrylic resin, and a resin having an alicyclic structure (for example, a norbornene resin). Among these, resins having an alicyclic structure, methacrylic resins, and (meth) acrylic acid ester-aromatic vinyl compound copolymer resins are preferable, and resins having an alicyclic structure are particularly preferable.

A resin having an alicyclic structure has good fluidity of the molten resin. Therefore, for example, when the light guide plate is manufactured by injection molding, the cavity of the mold can be filled with a low injection pressure, and a weld line is hardly generated. Moreover, when manufacturing a light-guide plate by extrusion molding, for example, there is little thickness nonuniformity at the time of shaping | molding, and the shaping | molding after shaping | molding is easy. Furthermore, since the resin having an alicyclic structure has extremely low hygroscopicity, it has excellent dimensional stability and hardly warps the light guide plate. Furthermore, since the specific gravity of the resin having an alicyclic structure is small, the light guide plate can be reduced in weight.

Examples of the resin having an alicyclic structure include polymer resins having an alicyclic structure in the main chain or side chain. Among them, a polymer resin having an alicyclic structure in the main chain is particularly suitable because it has good mechanical strength and heat resistance.
The alicyclic structure is preferably a saturated cyclic hydrocarbon structure.
The number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, preferably 30 or less, more preferably 20 or less, and particularly preferably 15 or less.
The ratio of the repeating unit having an alicyclic structure in the polymer resin having an alicyclic structure is preferably 50% by weight or more, more preferably 70% by weight or more, and 90% by weight or more. More preferably.

Examples of the resin having an alicyclic structure include a ring-opening polymer or a ring-opening copolymer of a norbornene monomer or a hydrogenated product thereof; an addition polymer or an addition copolymer of a norbornene monomer; Polymers of monocyclic olefin monomers or their hydrogenated products; Polymers of cyclic conjugated diene monomers or their hydrogenated products; Vinyl alicyclic hydrocarbon monomers Or a hydrogenated product thereof; a polymer of a vinyl aromatic hydrocarbon monomer or a hydrogenated product of an unsaturated bond part containing an aromatic ring of the copolymer; and the like. Among these, hydrogenated products of norbornene-based monomer polymers and hydrogenated products of unsaturated bonds including aromatic rings of vinyl aromatic hydrocarbon-based monomer polymers have mechanical strength and heat resistance. It is particularly suitable because of its excellent properties.

Furthermore, among the above transparent resins, methacrylic resins are excellent in transparency, strong and resistant to cracking, and therefore can be suitably used. Examples of the methacrylic resin include a methacrylic resin molding material containing 80% by weight or more of a methyl methacrylate polymer specified in JIS K6717. Among the methacrylic resins specified in this standard, methacrylic resins having a specified classification code 100-120 having a Vicat softening point temperature of 96 to 100 ° C. and a melt flow rate of 8 to 16 have appropriate fluidity and strength. Is preferred.

An antioxidant may be included in the light guide plate molding material in order to prevent oxidative degradation and thermal degradation during molding. Examples of the antioxidant include a phenolic antioxidant, a phosphorus antioxidant, and a sulfur antioxidant. Of these, phenolic antioxidants are preferred, and alkyl-substituted antioxidants are particularly preferred. In addition, an antioxidant may be used individually by 1 type and may be used combining two or more types by arbitrary ratios. The amount of the antioxidant is preferably 0.01 parts by weight or more, more preferably 0.02 parts by weight or more, preferably 2 parts by weight or less, more preferably 1 part by weight with respect to 100 parts by weight of the resin component. It is as follows.

In the molding material for the light guide plate, a light resistance stabilizer may be included in order to improve the light resistance of the light guide plate. Examples of the light resistance stabilizer include hindered amine light resistance stabilizer (HALS) and benzoate light resistance stabilizer. Among these, hindered amine light resistance stabilizers are preferred. In addition, a light-resistant stabilizer may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. The amount of the light-resistant stabilizer is preferably 0.01 parts by weight or more, more preferably 0.02 parts by weight or more, particularly preferably 0.05 parts by weight or more, preferably 2 parts by weight with respect to 100 parts by weight of the resin component. The amount is not more than parts by weight, more preferably not more than 1 part by weight, particularly preferably not more than 0.5 parts by weight.

The molding material for the light guide plate may further contain an optional additive as necessary. Examples of optional additives include stabilizers such as heat stabilizers, ultraviolet absorbers and near infrared absorbers; resin modifiers such as lubricants and plasticizers; colorants such as dyes and pigments; fluorescent brighteners; Examples thereof include an antistatic agent and a light diffusing agent. In addition, arbitrary additives may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

The dimensions of the main surface of the light guide plate (in the above embodiment, the dimensions in the X-axis direction and the Y-axis direction) are usually set according to the size of the effective surface of the liquid crystal panel of the liquid crystal display device in which the light guide plate is used. The In addition, the thickness of the light guide plate (in the embodiment described above, the dimension in the Z-axis direction) is usually equal to or less than the height of the light source (in the above-described embodiment, the dimension in the Z-axis direction). Furthermore, the thickness of the light guide plate is preferably thin from the viewpoint of reducing the product weight. For example, when the light guide plate is manufactured by injection molding, the thickness of the light guide plate is preferably 0.5 mm to 5 mm from the viewpoint of imparting the shape of the light introduction surface and moldability. When the thickness of the light guide plate becomes excessively thin, the pressure rise during injection molding becomes remarkable, and the light guide plate that can be molded by the molding machine of the same size tends to be limited to a small one. On the other hand, when the thickness of the light guide plate becomes excessively thick, it takes time for the cooling process at the time of manufacture, and productivity may deteriorate.

As the light guide plate, for example, one having a refractive index of 1.533 (critical angle 40.7 °) can be used.

When the light guide plate is made of resin, the light guide plate may cause a dimensional change (elongation or warpage) due to moisture absorption. In particular, when the size of the light guide plate is large (for example, 40 inches), the relative positional relationship between the light source and the light introduction surface changes in the lighting device due to the change in the size, and the light utilization efficiency decreases or local dimming occurs. It may cause problems. For this reason, the water absorption rate of the light guide plate is preferably set to 0.5% or less, more preferably 0.25% or less, and further preferably 0.05% or less. Examples of resins that can realize this include cyclic polyolefin (COP), polystyrene, polycarbonate (PC), and the like. The water absorption rate in this specification is determined according to JIS K7209 A method, after drying a test piece having a thickness of 3 mm and a disk shape having a diameter of 50 mm or a square having a side of 50 mm at 50 ° C. for 24 hours. It can be determined from the increase in weight when it is allowed to cool in a filter and immersed in water at 23 ° C. for 24 hours.

There is no limitation on the method of manufacturing the light guide plate, but it is preferably formed integrally from the viewpoint of productivity. Examples of production methods that can be integrally formed in this way include injection molding and extrusion molding.

Also, when manufacturing a light guide plate having a pattern, there is no particular limitation on the pattern forming method. For example, a flat light guide plate may be prepared in advance, and a pattern may be formed later on the surface of the light guide plate. In this case, as a method of forming a pattern on the surface of the flat light guide plate, for example, a method by cutting using a tool capable of forming a pattern of a desired shape, a mold having a desired shape by applying a curable resin Examples of the method include a method of curing in a transferred state, a method of forming by hot pressing, and a vacuum forming method.

As a method of forming a pattern on the surface of the light guide plate, for example, the pattern may be formed simultaneously with the formation of the light guide plate. In this case, for example, profile extrusion can be performed using a profile die having a shape corresponding to a desired pattern. Further, for example, a pattern may be formed by embossing after extrusion. Further, for example, a casting mold capable of forming a desired pattern shape may be prepared, and a light guide plate may be produced by casting using this casting mold, and the pattern may be formed simultaneously with the molding of the light guide plate. Further, when the light guide plate is manufactured by injection molding and the pattern is formed at the same time, a mold capable of forming a desired pattern may be used.

In addition, the mold used for the mold shape transfer to the photo-curing resin, the extrusion process using a modified die, the embossing, the casting, or the injection molding is, for example, a metal member of a mold using a tool capable of forming a desired pattern. It can be obtained by cutting, or electroforming on a member having a desired shape.

Further, as a method other than the integral molding, for example, a sheet corresponding to each region of the light guide plate may be prepared, and the light guide plate may be manufactured by combining and joining these sheets in a tile shape.

〔light source〕
Hereinafter, the light source will be described.
Examples of the light source include an LED, a laser diode, a cold cathode tube (CCFL, EEFL), a hot cathode tube (HCFL), and the like. Among these, LEDs are preferable from the viewpoints of luminous efficiency, high-speed light control, and the like. Examples of the LED include a blue-yellow pseudo white light emitting diode, a three-color (RGB) type white light emitting diode, and the like.

As the LED, for example, a surface-mounted LED, a side-emitting LED, or a bullet-type LED is used. The dimension of the light emitting part of the LED can be set according to the light distribution characteristic of the LED. Usually, the width and height of the light emitting part of the LED are made equal. However, when the LED has an elliptical or oval cross section, the LED having a different width and height may be used. Good.

A general high dome type LED has a Lambertian light distribution and emits a relatively large divergent light having a half-value angle (full-width at half maximum) of about 120 °. However, from the viewpoint of suppressing the spread of light, the LED has a full width at half maximum of preferably 35 ° or less, more preferably 30 ° or less, and particularly preferably 15 ° or less. Ideally, LEDs that emit as close to parallel light as possible are preferred. On the other hand, from the viewpoint of suppressing the darkening of the corresponding portion between the LEDs in the vicinity of the light incident portion of the light guide plate, the full width at half maximum of the LED is preferably 90 ° or more, more preferably 100 ° or more, and 110 °. The above is particularly preferable. In the present invention, an example in which the anisotropic light extraction region works as a light diffusion pattern for preventing light diffusion when light enters from the light guide direction is shown, and an LED having a wide full width at half maximum can be sufficiently used.

In addition, as a light source, you may use combining light emitting elements, such as LED, and optical elements, such as a lens. For example, even when an LED having a wide full width at half maximum is used, a light source that emits light at a full width at half maximum within the above-described preferable range can be realized by combining the LED and the lens.

Further, a light source capable of dimming may be obtained by combining a light source that always emits light and an optical shutter (for example, a liquid crystal panel) provided between the light source and the light introduction surface.

[Use]
The illumination device of the present invention is suitable as a backlight device that supplies light to a liquid crystal panel of a liquid crystal display device, for example. By providing the lighting device of the present invention in a liquid crystal display device, local dimming can be realized with a simple configuration in the liquid crystal display device.
The liquid crystal panel is a member in which, for example, an alignment film, a transparent electrode, a glass plate, a color filter, a polarizing plate, and the like are stacked and arranged at appropriate positions with a liquid crystal layer interposed therebetween. When the lighting device of the present invention is applied to a liquid crystal display device, the lighting device of the present invention is usually provided on the back side of the liquid crystal panel so that light can be supplied to the liquid crystal panel from the back side.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples, and may be arbitrarily set within the scope of the claims of the present invention and its equivalents. You can change it to

[Example 1]
A thermoplastic alicyclic structure-containing resin (trade name ZEONOR 1060R, manufactured by Nippon Zeon Co., Ltd., refractive index 1.53, water absorption 0.05%) was prepared. A light guide plate having a length of 200 mm, a width of 200 mm, and a plate thickness of 2 mm was produced by extrusion molding of this resin.
The light guide plate was divided into a matrix of 4 rows and 4 columns, and 16 regions were set. The dimensions of each region were 50 mm long and 50 mm wide.

A V-shaped groove pattern as shown in FIG. 1 was formed on the light extraction surface in the divided region by fine processing using a single crystal diamond tool (vertical angle 110 °). The groove pitch of the V-shaped groove pattern was 70 μm. Further, the V-shaped groove patterns are arranged in parallel along the same direction in the same region. Furthermore, the position of each area | region was made to be the same as that of the light-guide plate 300 demonstrated in 1st embodiment.
In addition, the back surface on the opposite side to the light extraction surface of the light guide plate was a smooth flat surface.

An LED (manufactured by OSRAM, LWM673-N2R2-5K8L) was prepared as a light source. Forty LEDs were installed on each of the four side surfaces of the light guide plate at intervals of 5 mm. The LEDs were wired so that they could be turned on and off every 10 consecutive groups.

FIG. 18 is a cross-sectional view schematically showing the vicinity of the light source of the illumination device configured in the present embodiment. As shown in FIG. 18, the light source 12 is installed at a position in front of each side surface 11 of the light guide plate 10. The light guide plate 10 was wrapped with a reflection sheet (trade name E6SV, manufactured by Toray Industries, Inc.) 17 from the end 14 of the light extraction surface 13 and the end 16 of the back surface 15 to the light source 12. Further, the reflection sheet 18 is brought into close contact with the back surface 15 of the light guide plate 10.

Furthermore, on the light extraction surface of the light guide plate, two prism sheets (trade name BEF3, manufactured by 3M) and a diffusion sheet (trade name LIGHTUP GM3, manufactured by Kimoto) were stacked in this order. The two prism sheets were designed such that the lens axes were orthogonal to each other.
As described above, an illumination device having a light guide plate and a light source was prepared.

The LED of the prepared lighting device blinked independently for each group. As a result, it was confirmed that light was extracted from the light extraction surface in the region of the light guide plate corresponding to each LED group. It was also confirmed that there was no light leakage from the light extraction surface in the region of the light guide plate that did not correspond to the group of LEDs that were lit.

From the above, it was confirmed that local dimming can be realized with a simple configuration according to the lighting apparatus of the present example.

The light guide plate of the present invention can be arbitrarily applied to optical applications, and is particularly suitable for an illumination device capable of surface light emission.
The illumination device of the present invention is suitable for use in a liquid crystal display device. The lighting device of the present invention can also be used for applications other than the backlight of a liquid crystal display device, for example, as a lighting device such as a show window.

DESCRIPTION OF SYMBOLS 1-5 Illuminating device 5A-5D Part of illuminating device 5 10 Light guide plate 11 Side surface of light guide plate 12 Light source 13 Light extraction surface 14 End portion of light extraction surface 15 Back surface 16 End portions of

back surface

17, 18 Reflective sheet 100 Light guide plate 101 Light extraction surface 102

Back surface

103, 104 Side surface 105

Pattern

106, 107 Slope 108 Pattern 109 Flat surface 110 Pattern 111 Surface of pattern 110 200 Light extraction plate 201 Light extraction surface 202

Back surface

203, 204 Side surface 205 Light guide plate region (anisotropic light extraction region) )
206 Area of light guide plate (anisotropic light extraction area)
207, 208 Pattern 209 The portion 209 of the side surface 204 located on the front side in the Y-axis direction of the region 206 of the light guide plate
300 Light guide plate 301 Light extraction surface 302 Back surface 303 to 306 Side surface (light introduction surface)
303a to 303d, 304a to 304f, 305a to 305d, 306a to 306f Light introduction region 311 to 316, 321 to 326, 331 to 336, 341 to 344 Light guide plate region (anisotropic light extraction region)
411 to 416, 421 to 426, 431 to 436, 441 to 444 Light source 500 Light guide plate 501 Light extraction surface 502

Back surface

503, 506 Side surface (light introduction surface)
504, 505 Side surface 503a to 503c, 506a to 506f Light introduction region 511 to 516, 521 to 526, 531 to 536 Light guide plate region 600 Light guide plate 601 Light extraction surface 602

Back surface

603, 606 Side surface (light introduction surface)
604, 605 Side surface 603a to 603c, 606a to 606f Light introduction region 611 to 516, 621 to 626, 631 to 636 Light guide plate region 700 Multi-layer light guide plate 812 to 816, 821, 824, 825, 836

Light source

911, 922 923, 926, 931 to 935 Light source A103 light A104 light

Claims

A light guide plate having a light introduction surface for introducing light, a light extraction surface from which light introduced from the light introduction surface is extracted, and a back surface located on the opposite side of the light extraction surface,
The light guide plate is divided into a plurality of regions as seen from the light extraction direction,
Light that is guided in a direction in which a plurality of regions out of the divided regions are guided in parallel with a predetermined virtual axis parallel to the light extraction surface and intersects the virtual axis. Is an anisotropic light extraction area higher than the extraction efficiency of
The light introduction surface has at least one light introduction region corresponding to each of the anisotropic light extraction regions;
The position of at least one of the anisotropic light extraction regions is such that light introduced from the corresponding light introduction region into the light guide plate passes through another anisotropic light extraction region having a different virtual axis direction. A light guide plate, the position of which is adjusted to reach the isotropic light extraction region.
The light guide plate is divided into a × b regions in a matrix of a rows and b columns (a and b are each an integer of 2 or more) as viewed from the light extraction direction,
The light guide plate according to claim 1, wherein more than half of the a × b regions are the anisotropic light extraction regions.
The light guide plate according to claim 2, wherein the a and b satisfy 2a + 2b ≧ a × b.
The light guide plate according to claim 1, wherein the light guide plate is integrally formed.
When the anisotropic light extraction region is guided to the at least one of the light extraction surface and the back surface in parallel with the virtual axis of the anisotropic light extraction region, the light is transmitted to the anisotropic light extraction region. As a light diffusion prevention pattern that functions as a light extraction pattern for emitting light from the light extraction surface and prevents the light from diffusing with respect to light guided in a direction intersecting the virtual axis of the anisotropic light extraction region The light guide plate according to claim 1, wherein the light guide plate is a region where a functioning pattern is formed.
The light guide plate according to claim 5, wherein the light guide plate has a plurality of hook-like patterns formed to extend in a direction perpendicular to the virtual axis of the anisotropic light extraction region in which the pattern is formed as the pattern.
The light guide plate according to claim 6, wherein the bowl-shaped pattern has a plurality of prism-like V-groove patterns parallel to each other.
The light guide plate according to claim 6, comprising a plurality of lenticular groove patterns parallel to each other as the bowl-shaped pattern.
A lighting device comprising the light guide plate according to claim 1.
The illuminating device according to claim 9, further comprising a light source capable of adjusting light for each of the anisotropic light extraction regions that irradiates light independently to each of the light introduction regions.
A light guide plate provided with two or more stacked,
The light guide plate has a light introduction surface for introducing light, a light extraction surface from which light introduced from the light introduction surface is extracted, and a back surface located on the opposite side of the light extraction surface, and extracts light. Divided into multiple areas as seen from the direction,
A plurality of regions among the divided regions are guided in a direction intersecting with the virtual axis, and light extraction efficiency is guided in a direction parallel to a predetermined virtual axis parallel to the light extraction surface. An anisotropic light extraction area that is higher than the light extraction efficiency
The light introduction surface has light introduction regions provided at least one place corresponding to each of the anisotropic light extraction regions from which light is extracted;
The position of at least one of the anisotropic light extraction regions is such that light introduced from the corresponding light introduction region into the light guide plate passes through another anisotropic light extraction region having a different virtual axis direction. The position is adjusted to reach the isotropic light extraction area,
Furthermore, an illuminating device provided with the light source which can irradiate light to each said light introduction area | region independently and can adjust light for every said anisotropic light extraction area | region.
Each of the light guide plates is divided into a × b regions in a matrix of a rows and b columns (a and b are each an integer of 2 or more) as viewed from the light extraction direction,
The lighting device according to claim 11, wherein more than half of the a × b regions are the anisotropic light extraction regions.
The illuminating device according to claim 12, wherein the number of the light guide plates stacked is n, wherein 2 × n × a + 2 × n × b ≧ a × b is satisfied.
The anisotropic light extraction region of the light guide plate is different from the light guided to the at least one of the light extraction surface and the back surface in parallel with the virtual axis of the anisotropic light extraction region. Light that functions as a light extraction pattern that emits light from the light extraction surface of the isotropic light extraction region and prevents the light from diffusing with respect to light guided in a direction intersecting the virtual axis of the anisotropic light extraction region The illumination device according to claim 11, wherein the illumination device is a region where a pattern functioning as a diffusion prevention pattern is formed.
The lighting device according to claim 14, wherein the pattern includes a plurality of hook-shaped patterns formed to extend in a direction orthogonal to the virtual axis of the anisotropic light extraction region in which the pattern is formed.
16. The illumination device according to claim 15, wherein the bowl-shaped pattern has a plurality of prism-like V-groove patterns parallel to each other.
The lighting device according to claim 15, wherein the bowl-shaped pattern has a plurality of lenticular groove patterns parallel to each other.