CN215867197U - Light guide plate and light guide plate system - Google Patents

Abstract

Provided are a light guide plate and a light guide plate system, wherein the light guide plate can prevent the appearance quality of the light guide plate from being reduced when light is emitted from the light guide plate even if the control angle of a prism is small. The light guide plate (1) has a 1 st end surface (10a) on which light emitted from a light source (20) enters, a 1 st main surface (10c) on which light emitted from the 1 st end surface (10a) exits, and a 2 nd main surface (10d) opposite to the 1 st main surface (10c), the 2 nd main surface (10d) has a 1 st prism (11) having a plurality of concave shapes formed two-dimensionally, and 1 or more concave 2 nd prisms (12) formed so as to overlap at least one of the plurality of 1 st prisms (11), and a control angle (theta 2) of the 2 nd prism (12) is larger than a control angle (theta 1) of the 1 st prism (11).

Description

Light guide plate and light guide plate system

Technical Field

The present invention relates to a light guide plate and a light guide plate system using the same.

Background

Conventionally, as a light guide plate system using a light guide plate, an edge-light type lighting device is known. The edge-light type lighting device includes a light guide plate and a light source disposed to face an end surface of the light guide plate.

As such an illumination device, for example, patent document 1 discloses a surface light source device including a plate-shaped light guide plate having a plurality of concave prisms formed on a main surface thereof, and a light source disposed to face an end surface of the light guide plate.

In such a lighting device, light emitted from the light source enters from an end surface of the light guide plate and is guided inside the light guide plate, and is reflected by the prism and is emitted to the outside of the light guide plate from a main surface on the opposite side of the main surface on which the prism is formed.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 11-219609

In a light guide plate system using a light guide plate having a concave prism formed on a main surface thereof, in order to suppress glare (glare), light emitted in a direction perpendicular to the main surface of the light guide plate (front direction) is distributed with a small amount of light. In this case, for example, it is conceivable to make the control angle of the concave prisms formed on the light guide plate small and make the inclination angle of the inner surfaces of the concave prisms gentle. Thus, the light emitted in the direction perpendicular to the main surface of the light guide plate can be reduced. Further, by making the control angle of the concave prisms small, it is possible to make the light traveling toward the end surface side opposite to the end surface on the side close to the light source more in the direction perpendicular to the main surface of the light guide plate. For example, when the light source is positioned above the light guide plate, a large amount of light can be emitted obliquely downward. Further, in this case, by making the prism horizontally long, a large amount of light can be emitted in the left-right direction of the light guide plate, and a wide-range light distribution can be realized.

However, there are problems as follows: in a light guide plate system using a light guide plate in which the control angle of a prism is small, if foreign matter such as dust adheres to the main surface of the light guide plate or foreign matter enters the inside of the light guide plate or the main surface of the light guide plate is damaged, the foreign matter or the damage is conspicuous, and the appearance quality of the light guide plate is degraded when light is emitted from the light guide plate.

SUMMERY OF THE UTILITY MODEL

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a light guide plate and a light guide plate system that can suppress deterioration in the appearance quality of the light guide plate when light is emitted from the light guide plate even if the control angle of a prism is made small.

In one embodiment of the light guide plate according to the present invention, the light guide plate includes a 1 st end surface on which light emitted from a light source enters, a 1 st main surface on which light emitted from the 1 st end surface exits, and a 2 nd main surface opposite to the 1 st main surface, and includes a 1 st prism having a plurality of concave shapes formed two-dimensionally on the 2 nd main surface, and 1 or more concave shape 2 nd prisms formed to overlap at least one of the plurality of 1 st prisms, and a control angle of the 2 nd prism is larger than a control angle of the 1 st prism.

In one embodiment of the light guide plate system of the present invention, the light guide plate includes the light guide plate and a light source that emits light incident on the 1 st end surface of the light guide plate.

According to the present invention, it is possible to suppress a reduction in the appearance quality of the light guide plate when light is emitted from the light guide plate.

Drawings

Fig. 1 is a diagram showing a lighting state of the lighting device according to embodiment 1.

Fig. 2 is an enlarged sectional view of a main part of the lighting device of embodiment 1.

Fig. 3 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to embodiment 1.

Fig. 4 is a partial sectional view of the light guide plate according to embodiment 1.

Fig. 5 is a diagram for explaining the optical action of the 1 st prism and the 2 nd prism of the light guide plate according to embodiment 1.

Fig. 6 is a diagram showing the configuration of the lighting device of comparative example 1.

Fig. 7 is a diagram for explaining an optical action of the light guide plate of the illumination device of comparative example 1.

Fig. 8 is a diagram for explaining an optical action of the light guide plate of the illumination device of comparative example 2.

Fig. 9 is a diagram for explaining an optical action of the light guide plate of the illumination device of embodiment 1.

Fig. 10 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to modification 1 of embodiment 1.

Fig. 11 is a partial sectional view of the light guide plate according to modification 1 of embodiment 1.

Fig. 12 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to modification 2 of embodiment 1.

Fig. 13 is a partial sectional view of a light guide plate according to modification 2 of embodiment 1.

Fig. 14 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to modification 3 of embodiment 1.

Fig. 15 is a partial sectional view of a light guide plate according to modification 3 of embodiment 1.

Fig. 16 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to embodiment 2.

Fig. 17 is a partial sectional view of the light guide plate according to embodiment 2.

Fig. 18 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to embodiment 3.

Fig. 19 is a partial sectional view of the light guide plate according to embodiment 3.

Fig. 20 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to embodiment 4.

Fig. 21 is a partial sectional view of the light guide plate according to embodiment 4.

Fig. 22 is a partial sectional view of a light guide plate according to a modification of embodiment 4.

Fig. 23 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to embodiment 5.

Fig. 24 is a diagram showing the structures of the light guide plate and the light source of the illumination device according to embodiment 6.

Fig. 25 is a partial sectional view of the light guide plate according to modification 1.

Fig. 26 is a partial sectional view of a light guide plate according to modification 2.

Fig. 27 is a partial sectional view of a light guide plate according to modification 3.

Description of the reference numerals

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1X, 1Y lighting device (light guide plate system)

2 main body part

3 light emitting part

10, 10A, 10B, 10C, 10D, 10E, 10F, 10I, 10J, 10K, 10X, 10Y light guide plate

10a 1 st end face

10b 2 nd end face

10c the 1 st main surface

10d 2 nd main surface

11, 11A 1 st prism

12, 12B, 12C 2 nd prism

13 rd 3 prism

14 th 4 prism

20, 20G light source

50 light absorber

Detailed Description

Hereinafter, embodiments of the present invention will be described. The embodiments described below are all specific examples of the present invention. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are examples and are not intended to limit the present invention. Thus, among the components in the following embodiments, components not described in the independent claims are described as arbitrary components.

The drawings are schematic and are not necessarily strictly illustrated. In the drawings, the same reference numerals are given to substantially the same components, and redundant description may be omitted or simplified. In the following embodiments, expressions such as "substantially" also mean that manufacturing errors, dimensional tolerances, and the like are included.

(embodiment mode 1)

First, a schematic configuration of the illumination device 1 according to embodiment 1 will be described with reference to fig. 1 and 2. Fig. 1 is a diagram showing a lighting state of the lighting device 1 according to embodiment 1. Fig. 2 is an enlarged sectional view of a main part of the lighting device 1. In fig. 1 and 2, the vertical direction is referred to as a 1 st direction D1, and the left-right direction (horizontal direction) perpendicular to the vertical direction is referred to as a 2 nd direction D2.

As shown in fig. 1, the lighting device 1 is an outdoor lighting device that irradiates illumination light for illuminating a road or the like, and is installed in a posture of being erected on the ground. Specifically, the lighting device 1 is a pole light (pole light) having an elongated and quadrangular prism shape, and includes an elongated body portion 2 and a light emitting portion 3 provided on an upper portion of the body portion 2. The light emitting unit 3 is provided at a position of 30cm to 90cm from the ground surface, for example. The shape of the lighting device 1 may be not a quadrangular prism but a cylindrical shape.

The lighting device 1 of the present embodiment is a downlighter lamp that irradiates illumination light toward the lower side of the light emitting section 3. By thus irradiating illumination light toward the lower side of the light emitting section 3, it is possible to suppress dazzling of a person passing through the periphery of the lighting device 1, compared with the case where illumination light is irradiated toward the front direction of the light emitting section 3 or upward of the light emitting section 3. The illumination device 1 irradiates illumination light so as to illuminate the foot side of a pedestrian, for example.

Further, the illumination device 1 irradiates illumination light that spreads in the left-right direction (the 2 nd direction D2 in fig. 1) of the light emitting section 3. That is, the light distribution of the illumination device 1 is a wide-range light distribution in which the irradiation region is expanded in the left-right direction of the illumination device 1. For example, by spreading the illumination light along the road direction, the front-rear direction along the road direction can be brightly illuminated. In fig. 1, the illumination region of the illumination light of the illumination device 1 is indicated by dotted hatching.

The illumination device 1 is an example of a light guide plate system using a light guide plate, and includes a light guide plate 10 and a light source 20, as shown in fig. 2. In the present embodiment, the lighting device 1 includes a light guide plate 10, a light source 20, a reflector 30, and a light-transmitting panel 40 as a light emitting section 3. The light guide plate 10, the light source 20, the reflector 30, and the light transmissive panel 40 may be directly fixed to the main body 2, or may be indirectly fixed to the main body 2 via a holder or the like (not shown). The main body 2 is an outer member forming an outer contour of the lighting device 1, and is a housing accommodating and holding the light guide plate 10, the light source 20, the reflection plate 30, and the light transmissive panel 40. The main body 2 is a rigid body made of metal or resin, for example.

Hereinafter, each component of the light emitting section 3 of the illumination device 1 will be described in detail with reference to fig. 3 and 4 with reference to fig. 1 and 2. Fig. 3 is a diagram showing the structures of the light guide plate 10 and the light source 20 of the illumination device 1 according to embodiment 1. Fig. 4 is a partial sectional view of the light guide plate 10. In fig. 3, (a) shows a side view of the light guide plate 10 and the light source 20, and (b) shows a cross-sectional view taken along line IIIB-IIIB of (a). In FIG. 4, (a), (b), and (c) are sectional views taken along lines IVA-IVA, IVB-IVB, and IVC-IVC of FIG. 3, respectively.

First, the light guide plate 10 will be described. The light guide plate 10 is an optical member having a function of guiding light. In the present embodiment, the light guide plate 10 is a flat plate-like light guide body having a rectangular planar shape. The light guide plate 10 is a light-transmitting member having light-transmitting properties, and is made of a light-transmitting material. The light guide plate 10 is made of a light-transmitting resin material such as an acrylic resin such as PMMA (polymethyl methacrylate) resin or a polycarbonate resin. The light guide plate 10 may be made of a transparent resin material having high transmittance to the extent that the front surface is seen through. In the present embodiment, the light guide plate 10 is formed of a transparent plate made of acrylic resin. The light guide plate 10 is not limited to a transparent resin plate made of a resin material, and may be a glass plate made of transparent glass.

As shown in fig. 3, the light guide plate 10 has a 1 st end face 10a and a 2 nd end face 10b opposite to the 1 st end face 10 a. The 1 st end face 10a and the 2 nd end face 10b are side faces of the light guide plate 10. Since the light guide plate 10 is plate-shaped, the 1 st end surface 10a and the 2 nd end surface 10b are elongated, respectively. In the present embodiment, the 1 st end surface 10a and the 2 nd end surface 10b are each elongated and substantially rectangular.

In the present embodiment, the pair of 1 st end surface 10a and 2 nd end surface 10b face each other in a direction orthogonal to the thickness direction of the light guide plate 10. That is, the 2 nd end surface 10b is located opposite to the 1 st end surface 10 a. For example, the 1 st end surface 10a and the 2 nd end surface 10b are flat and substantially parallel to each other. The 1 st end surface 10a is not limited to a flat surface, and may include a surface curved in a concave shape or a surface recessed in a concave shape for each light emitting element 22 of the light source 20 in order to efficiently input light from the light source 20 to the light guide plate 10. Further, the 2 nd end face 10b is not limited to a flat surface. For example, the 2 nd end surface 10b may be an inclined surface or a concave-convex surface.

The 1 st end surface 10a is a light incident surface on which light emitted from the light source 20 enters. Specifically, the 1 st end face 10a faces the light source 20. That is, the 1 st end face 10a is a face on the light source 20 side, and the 2 nd end face 10b is a face on the opposite side to the light source 20 side.

The light guide plate 10 further has a 1 st main surface 10c and a 2 nd main surface 10d opposite to the 1 st main surface 10 c. The 1 st main surface 10c and the 2 nd main surface 10d are surfaces facing each other when the light guide plate 10 is viewed from the front. In the present embodiment, the 1 st main surface 10c is a front surface which is a front surface of the lighting device 1, and the 2 nd main surface 10d is a rear surface which is a rear surface of the lighting device 1. The 1 st main surface 10c and the 2 nd main surface 10d face each other in the thickness direction of the light guide plate 10. In the present embodiment, the 1 st main surface 10c and the 2 nd main surface 10d are respectively planar and substantially parallel. Since the front surface of the light guide plate 10 is substantially rectangular, the 1 st main surface 10c and the 2 nd main surface 10d are substantially rectangular.

The 1 st main surface 10c is a light exit surface from which light incident from the 1 st end surface 10a exits. Therefore, the first main surface 10c becomes a pseudo-light emitting surface because the light guided in the light guide plate 10 is emitted to the outside. In the present embodiment, the 1 st main surface 10c is a light extraction surface for extracting light guided in the light guide plate 10.

The 2 nd main surface 10d is a light control surface for controlling light incident from the 1 st end surface 10 a. In the present embodiment, the 2 nd main surface 10d has a light reflection structure for reflecting light that enters from the 1 st end surface 10a and is guided inside the light guide plate 10.

Specifically, as shown in fig. 3 and 4, a plurality of 1 st concave prisms 11 (1 st concave prisms) are formed as a light reflecting structure on the 2 nd main surface 10 d. The 1 st prisms 11 are formed in a two-dimensional shape. Specifically, when the light guide plate 10 is viewed from the main surface perpendicular direction (front direction) of the 2 nd main surface 10D, the 1 st prisms 11 are arranged in plural numbers along the 1 st direction D1 which is a direction from one of the 1 st end surface 10a and the 2 nd end surface 10b toward the other, and are arranged in plural numbers along the 2 nd direction D2 which is substantially orthogonal to the 1 st direction. In the present embodiment, the 1 st direction D1 is a vertical direction and is an optical axis direction of the light source 20. Further, the 2 nd direction D2 orthogonal to the 1 st direction D1 is a horizontal direction (left-right direction), and is a direction orthogonal to the optical axis of the light source 20. The 1 st prisms 11 may be formed over the entire 2 nd main surface 10d, or may be formed partially.

As shown in fig. 3 and fig. 4 (b) and (c), a concave 2 nd prism 12 (2 nd concave prism) is further formed as a light reflection structure on the 2 nd main surface 10 d. The 2 nd prism 12 is formed to overlap at least one of the 1 st prisms 11. In the present embodiment, 12 nd prism 12 is formed at 1 st prism 11. In this case, it is preferable that the center of the 1 nd 2 nd prism 12 overlaps with the center of the 1 st prism 11. In addition, the 2 nd prism 12 is formed in all the 1 st prisms 11, but is not limited thereto.

Thus, the 2 nd prism 12 is an additional prism additionally formed to the 1 st prism 11. That is, the 1 st prism 11 is a main prism that determines the main light distribution of the light emitted from the light guide plate 10, and the 2 nd prism 12 is a sub-prism that finely adjusts the light distribution of the light guide plate 10 generated by the 1 st prism 11.

In the present embodiment, when the 2 nd main surface 10d is viewed from the front, the 2 nd prism 12 is positioned inside the 1 st prism 11. That is, when the 2 nd main surface 10d is viewed from the front, the 2 nd prism 12 is included in the 1 st prism 11. Therefore, when the 2 nd main surface 10d is viewed from the front, the opening area of the 2 nd prism 12 is smaller than the opening area of the 1 st prism 11.

For example, when the 2 nd main surface 10d is viewed from the front, the total opening area of the 2 nd prisms 12 in the 1 st prism 11 is not more than 1/10 of the opening area of the 1 st prism 11. In this case, the total opening area of the 2 nd prisms 12 at 1 st prism 11 is preferably 50 to 1 of the opening area of the 1 st prism 11, and more preferably 100 to 1.

The 1 st prism 11 is a reflection prism, and has a 1 st reflection surface 11a (1 st light control surface) that reflects light traveling in the light guide plate 10 toward the 1 st main surface 10 c. Specifically, the 1 st reflecting surface 11a is substantially a half of the inner surface of the 1 st prism 11 on the light source 20 side. In the present embodiment, the angle θ 1 formed by the 1 st reflecting surface 11a, i.e., the 1 st inner surface, of the inner surfaces of the 1 st prism 11 and the 2 nd main surface 10d is the same as the angle θ 1 'formed by the 2 nd inner surface 11 a' of the inner surface of the 1 st prism 11 opposite to the light source 20 side and the 2 nd main surface 10d, but the present invention is not limited thereto. That is, the angle θ 1 and the angle θ 1' may be different. In this case, in order to reduce light leakage to the back surface side (the 2 nd main surface 10d side) of the light guide plate 10 and to increase the ratio of the control light to the front surface side (the 1 st main surface 10c side), the angle θ 1' > the angle θ 1 is preferable.

The 2 nd prism 12 is also a reflection prism, and has a 2 nd reflection surface 12a (2 nd light control surface) for reflecting light traveling in the light guide plate 10 toward the 1 st main surface 10c side. Specifically, the 2 nd reflecting surface 12a is substantially a half inner surface of the 2 nd prism 12 on the light source 20 side.

The 1 st prism 11 and the 2 nd prism 12 are each a minute concave portion processed into a predetermined shape. The 1 st prism 11 and the 2 nd prism 12 are micro prisms having a micron size. The 1 st prism 11 and the 2 nd prism 12 can be formed by laser processing or cutting the 2 nd main surface 10d of the flat light guide plate 10. Further, the light guide plate 10 having the 1 st prism 11 and the 2 nd prism 12 can be manufactured by molding using a mold.

In the present embodiment, the 1 st prism 11 is a long groove elongated in the 2 nd direction D2 (direction intersecting the optical axis of the light source 20), which is the left-right direction. That is, the 1 st prism 11 is a long groove prism. By forming the 1 st prism 11 as a main prism in such a shape, a large amount of light can be emitted from the light guide plate 10 in the 2 nd direction D2 (the left-right direction of the light guide plate 10), and a wide-range light distribution can be realized. That is, as shown in fig. 1, the light distribution of the illumination device 1 can be made a wide-range light distribution. Specifically, the opening shape of the 1 st prism 11 is a horizontally long racetrack shape when the 2 nd main surface 10d is viewed from the front (i.e., when the 2 nd main surface 10d is viewed from the main surface vertical direction). When the 2 nd main surface 10d is viewed from the front, the opening shape of the 2 nd prism 12 is circular. In this case, the diameter of the opening of the 2 nd prism 12 is preferably smaller than the width of the opening of the 1 st prism 11.

As shown in fig. 4 (b) and (c), the 2 nd prism 12 is formed such that the base of the 1 st prism 11 is deeper. Specifically, the 2 nd prism 12 is formed to protrude in a protruding manner in the depth direction from the bottom of the 1 st prism 11. Therefore, in the portion where the 1 st prism 11 overlaps the 2 nd prism 12, the 1 st reflection surface 11a of the 1 st prism 11 is formed on the 2 nd main surface 10d side in the cross-sectional view of the light guide plate 10, and the 2 nd reflection surface 12a of the 2 nd prism 12 is formed in the depth direction continuously from the 1 st reflection surface 11 a.

As shown in fig. 4 (a), the 1 st prism 11 has a cross-sectional shape when cut along the 1 st direction D1 in a portion of the 1 st prism 11 not overlapping the 2 nd prism 12, which is substantially triangular. Therefore, the 1 st reflecting surface 11a of the 1 st prism 11 is a plane inclined with respect to the 2 nd main surface 10 d. In the present embodiment, the 1 st prism 11 has an isosceles triangle shape where θ 1 is θ 1' when cut along the 1 st direction D1. Therefore, the half of the inner surfaces of the 1 st prism 11 opposite to the light source 20 side also becomes inclined surfaces inclined at the same inclination angle as the 1 st reflecting surface 11 a. In the present invention, θ 1 does not necessarily have to be θ 1'.

On the other hand, the 2 nd prism 12 formed to overlap the 1 st prism 11 is substantially conical. That is, the 2 nd prism 12 is a conical prism. Therefore, the 2 nd reflecting surface 12a of the 2 nd prism 12 is a curved surface inclined with respect to the 2 nd main surface 10 d. As shown in fig. 4 (b), in the present embodiment, the cross-sectional shape of the 2 nd prism 12 when cut along the 1 st direction D1 is a substantially isosceles triangle with a vertex angle curved. Therefore, the half of the inner surfaces of the 2 nd prism 12 opposite to the light source 20 side also becomes inclined surfaces inclined at the same inclination angle as the 2 nd reflecting surface 12 a. The 2 nd prism 12 may have a substantially truncated conical shape.

Further, as shown in fig. 4 (b), the control angle θ 2 of the 2 nd prism 12 is larger than the control angle θ 1 of the 1 st prism 11(θ 2 > θ 1). The control angle θ 1 of the 1 st prism 11 is an angle formed by the 2 nd main surface 10D and the 1 st reflection surface 11a in a cross section when the 1 st prism 11 is cut along the 1 st direction D1. The control angle θ 2 of the 2 nd prism 12 is an angle formed by the opening surface (the surface parallel to the 2 nd main surface 10D) of the 2 nd prism 12 and the 2 nd reflecting surface 12a in the cross section when the 2 nd prism 12 is cut along the 1 st direction D1.

In the present embodiment, the control angle θ 1 of the 1 st prism 11 is set to be small and 45 ° or less, and the inclination angle of the 1 st reflecting surface 11a is made gentle. This makes it possible to obtain light distribution with less light emitted in the direction perpendicular to the main surface (front direction) of the light guide plate 10. Specifically, the control angle θ 1 of the 1 st prism 11 is preferably 10 ° or more and 40 ° or less. In this case, the control angle θ 2 of the 2 nd prism 12 is larger than the control angle θ 1 of the 1 st prism 11 as described above. The control angle θ 2 of the 2 nd prism 12 is not particularly limited if it is larger than the control angle θ 1 of the 1 st prism 11, but the control angle θ 2 of the 2 nd prism 12 is preferably larger than 40 °. For example, in the present embodiment, the control angle θ 1 of the 1 st prism 11 is set to 20 °, and the control angle θ 2 of the 2 nd prism 12 is set to 60 °.

In addition, since the control angle θ 2 of the 2 nd prism 12 and the control angle θ 1 of the 1 st prism 11 are different, a connection portion between the 1 st reflection surface 11a and the 2 nd reflection surface 12a is curved.

According to the light guide plate 10 configured as described above, light incident from the light source 20 to the light guide plate 10 is reflected by the 1 st prism 11 or the 2 nd prism 12 and is emitted from the 1 st main surface 10c to the outside of the light guide plate 10.

Specifically, as shown in fig. 5 (a), a part of light incident from the light source 20 and guided through the light guide plate 10 is totally reflected at the interface between the 1 st reflecting surface 11a of the 1 st prism 11 and the air layer. At this time, since the control angle θ 1 of the 1 st prism 11 is 40 ° or less, the light totally reflected by the 1 st reflecting surface 11a travels toward the 2 nd end surface 10b side in the direction (front direction) perpendicular to the 1 st main surface 10c of the light guide plate 10. That is, the ratio of light toward the 2 nd end face 10b can be made larger than that toward the front direction and the 1 st end face 10 a.

In the present embodiment, since the light guide plate 10 is disposed such that the 1 st main surface 10c is parallel to the 1 st direction D1 which is the vertical direction, the light totally reflected by the 1 st reflecting surface 11a travels downward in the front direction of the light guide plate 10. That is, the light totally reflected on the 1 st reflecting surface 11a travels obliquely downward (in the direction toward the ground).

As shown in fig. 5 (b), another part of the light incident from the light source 20 and guided in the light guide plate 10 is totally reflected at the interface between the 2 nd reflecting surface 12a of the 2 nd prism 12 and the air layer. At this time, since the control angle θ 2 of the 2 nd prism 12 is larger than the control angle θ 1 of the 1 st prism 11 (for example, the control angle θ 2 is larger than 40 °), the light totally reflected by the 2 nd reflecting surface 12a travels toward the 1 st end surface 10a (toward the light source 20) than the light reflected by the 1 st reflecting surface 11 a.

In the present embodiment, since the light guide plate 10 is disposed such that the 1 st main surface 10c is parallel to the 1 st direction D1 which is the vertical direction, the light totally reflected by the 2 nd reflection surface 12a travels toward the front direction of the light guide plate 10 or upward in the front direction of the light guide plate 10. That is, the light totally reflected by the 2 nd reflecting surface 12a travels in the horizontal direction or obliquely upward (in a direction away from the ground).

Thus, the light incident on the light guide plate 10 from the light source 20 is reflected by the 1 st prism 11 or the 2 nd prism 12 and enters the 1 st main surface 10c, and the 1 st main surface 10c emits pseudo-planar light. At this time, the light reflected by the 1 st prism 11 or the 2 nd prism 12 is emitted to the outside of the light guide plate 10 with a predetermined light distribution. In the present embodiment, the 1 st prism 11 as a main prism for determining the light distribution of the light guide plate 10 is a long groove prism and the control angle θ 1 of the 1 st prism 11 is 40 ° or less, so that light having a light distribution peak obliquely downward and having a wide light distribution is emitted from the light guide plate 10.

Next, the light source 20 will be described. The light source 20 is a light emitting device that emits light incident on the light guide plate 10. Specifically, the light source 20 emits light incident on the 1 st end surface 10a of the light guide plate 10.

As shown in fig. 3, the light source 20 is disposed to face the 1 st end face 10a of the light guide plate 10. That is, the light source 20 and the light guide plate 10 are in an edge light configuration. Specifically, the light emitting surface of the light source 20 faces the 1 st end surface 10a of the light guide plate 10. In the present embodiment, the light guide plate 10 is disposed such that the 1 st end surface 10a is positioned on the upper side in the vertical direction, and therefore the light source 20 is disposed above the 1 st end surface 10 a.

In the present embodiment, the light source 20 is an LED module including LEDs. The light source 20 emits, for example, white light. The white light emitted from the light source 20 enters the light guide plate 10 from the 1 st end face 10a of the light guide plate 10.

The light source 20 has a substrate 21 and 1 or more light emitting elements 22 mounted on the substrate 21. In the present embodiment, since the light source 20 is an elongated LED module, the plurality of light emitting elements 22 are linearly mounted in a row on the elongated 1 substrate 21.

In the present embodiment, the light source 20 is disposed such that the optical axis of the light source 20 is in the 1 st direction D1. The optical axis of the light source 20 is the optical axis of each light emitting element 22.

The substrate 21 is, for example, a wiring substrate on which wiring of a predetermined pattern is formed. As the substrate 21, a resin substrate, a ceramic substrate, a metal substrate covered with an insulating film, or the like can be used.

The light emitting element 22 is an LED element made of an LED. In the present embodiment, the light emitting element 22 is a Surface Mount (SMD) type LED element which is packaged individually, and includes a container (package) made of resin or the like, an LED chip (bare chip) arranged in the container, and a sealing member which seals the LED chip. Specifically, the light emitting element 22 is an SMD type white LED element that emits white light. In this case, a blue LED chip that emits blue light when energized is used as the LED chip, and a silicone resin (phosphor-containing resin) containing a yellow phosphor such as YAG is used as the sealing member filled in the container.

The light source 20 emits light by power supplied from a power supply. The power supply is configured by, for example, a circuit board on which a plurality of circuit components are mounted, and receives and converts commercial ac power into predetermined power (for example, dc power) to supply the power to the light source 20. Thereby, the light emitting element 22 of the light source 20 emits light. The power supply may be built in the lighting device 1 or may be separate from the lighting device 1. The light source 20 may be configured to be subjected to dimming control and/or color modulation control.

Next, the reflection plate 30 will be described. As shown in fig. 2, the reflection plate 30 is disposed on the one surface side of the light guide plate 10 on which the 1 st prism 11 and the 2 nd prism 12 are formed. That is, the reflection plate 30 is disposed on the 2 nd main surface 10d side of the light guide plate 10. Specifically, the reflection plate 30 is disposed such that the reflection surface of the reflection plate 30 faces the 2 nd main surface 10 d. Accordingly, light leaking to the outside from the 2 nd main surface 10d among the light guided by the light guide plate 10 can be reflected by the reflection plate 30, returned to the light guide plate 10, and emitted from the 1 st main surface 10c, and therefore, the light extraction efficiency of the light guide plate 10 can be improved.

The reflection plate 30 is formed of, for example, a resin material or a metal material. Specifically, the reflection plate 30 may be a white resin sheet made of a resin material such as PBT (polybutylene terephthalate), a metal plate made of a metal material such as aluminum, or a structure in which a metal film such as aluminum or a white resin is formed on a base material.

Next, the light transmitting panel 40 will be explained. As shown in fig. 2, light-transmitting panel 40 is disposed on one surface side of light guide plate 10 on which no 1 st prism 11 or no 2 nd prism 12 is formed. That is, the light-transmitting panel 40 is disposed on the 1 st main surface 10c side (light exit surface side) of the light guide plate 10. Specifically, the light-transmitting panel 40 is a front panel positioned in front of the light guide plate 10 in the light emission direction. Thus, the light-transmitting panel 40 covers the 1 st main surface 10c of the light guide plate 10. By disposing the light-transmitting panel 40 in this manner, the light guide plate 10 can be protected as compared with a case where the light guide plate 10 is exposed as an outer contour of the lighting device 1.

The light emitted from the 1 st main surface 10c of the light guide plate 10 enters the light transmissive panel 40, passes through the light transmissive panel 40, and is emitted to the outside of the light transmissive panel 40. Therefore, the outer surface of the light-transmitting panel 40 serves as a light-emitting surface of the light-emitting section 3. Specifically, the outer surface of the light-transmitting panel 40 serves as a light-emitting surface of the lighting device 1. In the present embodiment, the light transmitting panel 40 is fitted into the opening of the main body 2.

The light transmitting panel 40 is a light transmitting member having light transmittance. The light-transmitting panel 40 is preferably made of a transparent material having a high light transmittance so as not to absorb light emitted from the 1 st main surface 10c of the light guide plate 10. Since the lighting device 1 is used for outdoor lighting, the translucent panel 40 preferably has durability, water resistance, and the like. The light-transmitting panel 40 is a flat transparent plate made of acrylic resin or glass material, for example. The light-transmitting panel 40 is not limited to a transparent plate, and may be a diffusion plate for diffusing light.

Next, the operational effects of the illumination device 1 according to the present embodiment will be described together with the process of obtaining an embodiment of the present invention with reference to fig. 6 to 9.

Fig. 6 is a diagram showing the configuration of an illumination device 1X of comparative example 1. Fig. 7 is a diagram for explaining an optical action of the light guide plate 10X in the illumination device 1X of comparative example 1 shown in fig. 6. Fig. 8 is a diagram for explaining an optical action of the light guide plate 10Y in the illumination device 1Y of comparative example 2. Fig. 9 is a diagram for explaining an optical action of the light guide plate 10 in the illumination device 1 of embodiment 1.

The lighting device 1X of comparative example 1 shown in fig. 6 differs from the lighting device 1 shown in fig. 3 in the structure of the light guide plate 10X. Specifically, the light guide plate 10X shown in fig. 6 is configured such that the 2 nd prism 12 is not formed, and the control angle θ X of the prism 11X becomes larger (e.g., θ X > 40 °) with respect to the light guide plate 10 shown in fig. 3. Specifically, the control angle θ X of the prism 11X is 60 °. The configuration other than this is the same as that of the lighting device 1 shown in fig. 3.

The structure of the light guide plate 10Y is different in the illumination device 1Y of the comparative example 2 shown in fig. 8 from the illumination device 1X of the comparative example 1 shown in fig. 6 and 7. Specifically, in the light guide plate 10Y shown in fig. 8, the control angle θ Y of the prism 11Y is smaller (e.g., θ Y ≦ 40 °) than the light guide plate 10X shown in fig. 7. Specifically, the control angle θ Y of the prism 11Y of the light guide plate 10Y of the comparative example 2 is the same as the control angle θ 1 of the 1 st prism 11 of the light guide plate 10 of the above-described embodiment 1. More specifically, the control angle θ Y of the prism 11Y of the light guide plate 10Y of comparative example 2 is 20 °. The configuration other than this is the same as that of the illumination device 1X shown in fig. 6 and 7.

As shown in fig. 7, in the illumination device 1X of comparative example 1 shown in fig. 6, the control angle θ X of the prism 11X is larger than 40 °. Therefore, in the lighting device 1X of comparative example 1, as shown in fig. 7, light incident from the light source 20 into the light guide plate 10X is reflected by the prism 11X and travels toward the front direction of the light guide plate 10X or the upper side of the front direction of the light guide plate 10X. That is, the illumination device 1X of comparative example 1 irradiates illumination light toward the line of sight of the user.

At this time, as shown in fig. 7, when foreign matter 100 such as dust adheres to the 1 st main surface 10c of the light guide plate 10X, the light emitted from the light guide plate 10X is reflected by the foreign matter 100, but since the illumination device 1X irradiates illumination light in the line-of-sight direction of the user, the light reflected by the foreign matter 100 is canceled by the illumination light irradiated from the illumination device 1X. As a result, the light reflected by the foreign substance 100 is inconspicuous. That is, according to the lighting device 1X of comparative example 1, even if the foreign substance 100 adheres to the light guide plate 10X, the user is not easily aware of the presence of the foreign substance 100.

In contrast, according to the illumination device 1Y of comparative example 2 shown in fig. 8, the control angle θ Y of the prism 11Y is 40 ° or less. Therefore, according to the illumination device 1Y of comparative example 2, as shown in fig. 8, the light incident from the light source 20 and entering the light guide plate 10Y is reflected by the prism 11Y and travels toward the lower side in the front direction of the light guide plate 10Y. That is, the lighting device 1Y of comparative example 2 has an advantage that glare (flare) can be suppressed because illumination light is not irradiated much in the line-of-sight direction of the user.

However, according to the lighting device 1Y of the comparative example 2, as shown in fig. 8, when the foreign substance 100 adheres to the 1 st main surface 10c of the light guide plate 10Y, the lighting device 1Y does not emit the illumination light in the line of sight direction of the user so much, and therefore, when the light emitted from the light guide plate 10Y is reflected by the foreign substance 100, the reflected light by the foreign substance 100 is conspicuous. That is, unlike the lighting device 1X of comparative example 1, the lighting device 1Y of comparative example 2 does not eliminate the reflected light due to the foreign object 100 from the illumination light irradiated from the lighting device 1Y, and therefore the light reflected by the foreign object 100 is conspicuous. As a result, in the lighting device 1Y of comparative example 2, if the foreign substance 100 adheres to the light guide plate 10Y, the user can easily recognize the presence of the foreign substance 100.

In addition, not only when the foreign matter 100 adheres to the light guide plate 10Y, but also when the foreign matter 100 adheres to an optical component (for example, a light-transmitting panel disposed in front of the light guide plate 10Y or a reflective plate that reflects light emitted from the light guide plate 10Y) through which light emitted from the light guide plate 10Y is transmitted or reflected, or when the foreign matter 100 is mixed into the light guide plate 10Y in a manufacturing process or the like, the foreign matter 100 is conspicuous for the same reason as when the foreign matter 100 adheres to the light guide plate 10Y when the light guide plate 10Y having the small control angle θ Y of the prism 11Y is used. Further, not only in the case where the foreign matter 100 is in close contact with the light guide plate 10Y or the optical component (in the case of a close-contact type foreign matter), but also in the case where the foreign matter 100 is not in close contact with the light guide plate 10Y or the optical component (in the case of a non-close-contact type foreign matter), if the foreign matter 100 is present on the optical path of the light emitted from the light guide plate 10Y, the foreign matter 100 is conspicuous for the same reason as described above. In addition, the foreign matter 100 is not limited to the surface, and the damage is noticeable for the same reason as described above even when the surface of the light guide plate 10Y is damaged.

In this way, according to the illumination device 1Y using the light guide plate 10Y in which the control angle θ Y of the prism 11Y is made small, although strong light can be suppressed by irradiating illumination light obliquely downward, if foreign matter 100 such as dust adheres to the main surface of the light guide plate 10Y or an optical component, or foreign matter is mixed into the light guide plate 10Y, or the main surface of the light guide plate 10 is damaged, the foreign matter 100 or the damage is conspicuous. As a result, the appearance quality of the light guide plate 10Y is degraded when light is emitted from the light guide plate 10Y.

In view of the above problems, the inventors of the present invention have studied and found the following idea: in the case of a main prism having a small control angle, a prism having a control angle larger than the control angle is superimposed on the main prism, so that foreign matter or damage can be made inconspicuous even if the control angle of the main prism is small.

Specifically, according to the light guide plate 10 of the present embodiment, 1 or more concave 2 nd prisms 12 are formed so as to overlap at least one of the 1 st prisms 11 having a plurality of concave shapes formed two-dimensionally on the 2 nd main surface 10d, and the control angle θ 2 of the 2 nd prisms 12 is made larger than the control angle θ 1 of the 1 st prisms 11.

With this configuration, as shown in fig. 5 (a), of the light emitted from the light source 20 and entering the light guide plate 10 from the 1 st end face 10a, the light reflected by the 1 st prism 11 having a small control angle θ 1 travels toward the 2 nd end face 10b side with respect to the front direction of the light guide plate 10. In the present embodiment, the light reflected by the 1 st prism 11 is directed obliquely downward.

Further, since the 2 nd prism 12 having the control angle θ 2 larger than the control angle θ 1 of the 1 st prism 11 is formed to overlap the 1 st prism 11, as shown in fig. 5 (b), of the light emitted from the light source 20 and incident on the light guide plate 10 from the 1 st end face 10a, the light reflected by the 2 nd prism 12 having the control angle θ 2 is advanced toward the 1 st end face 10a side (toward the light source 20 side) than the light reflected by the 1 st prism 11. For example, the light reflected by the 2 nd prism 12 travels toward the front of the light guide plate 10 or upward in the front of the light guide plate 10.

Therefore, as shown in fig. 9, even if the foreign substance 100 adheres to the 1 st main surface 10c of the light guide plate 10, the light reflected by the foreign substance or the damage is inconspicuous due to the light reflected by the 2 nd prism 12 when the light guide plate 10 is viewed from the front or obliquely above. In addition, not only when the foreign matter 100 adheres to the light guide plate 10, but also when the foreign matter adheres to an optical component through which light emitted from the light guide plate 10 is transmitted or reflected, or the foreign matter is mixed into the light guide plate 10, or a main surface of the light guide plate 10 is damaged, when the light guide plate 10 is viewed from the front or obliquely upward, the light reflected by the foreign matter or the damage is not conspicuous due to the light reflected by the 2 nd prism 12.

As described above, according to the light guide plate 10 of the present embodiment, even if foreign matter exists on the light guide plate 10 or the like or the light guide plate 10 is damaged, the user is less likely to recognize the existence of the foreign matter or the damage. That is, the foreign matter or damage is made inconspicuous by the light distribution of the 2 nd prism 12, and the user can be shielded by the light distribution of the 2 nd prism 12. As a result, the deterioration of the appearance quality of the light guide plate 10 when light is emitted from the light guide plate 10 can be suppressed. In addition, similarly to the illumination device 1 including the light guide plate 10, the deterioration of the appearance quality of the light emitting portion 3 of the illumination device 1 at the time of lighting can be suppressed.

In addition, according to the light guide plate 10 of the present embodiment, when the 2 nd main surface 10d is viewed from the front, the 2 nd prism 12 is positioned inside the 1 st prism 11. That is, when the 2 nd main surface 10d is viewed from the front, the 2 nd prism 12 is included in the 1 st prism 11.

Therefore, in the method of arranging the prism patterns when the light guide plate 10 is viewed from the front direction, the arrangement of the 1 st prism 11, which is a main prism, is dominant, so that the aesthetic appearance of the arrangement in appearance is not spoiled by the 2 nd prism 12, and the appearance of the light guide plate 10 is improved.

In the light guide plate 10 of the present embodiment, the 1 st prism 11 is a long groove elongated in a direction intersecting the optical axis of the light source 20.

With this configuration, not only the light distribution ratio of light traveling toward the 2 nd end face 10b side with respect to the front direction of the light guide plate 10 (light traveling obliquely downward in the present embodiment) but also the light distribution ratio of light traveling in the left-right direction of the light guide plate 10 (light traveling toward the 2 nd direction D2 in the present embodiment) can be increased. This enables a wide-range light distribution.

Further, when the 1 st prism 11 is a long groove, the opening shape of the 2 nd prism 12 is preferably circular when the 2 nd main surface 10d is viewed from the front. Specifically, the 2 nd prism 12 in the present embodiment is substantially conical.

With this configuration, since the 1 st prism 11 can efficiently generate light distribution in obliquely downward and left-right directions, even if the 2 nd prism 12 is overlapped with the 1 st prism 11, it is possible to suppress deterioration of light distribution characteristics of a wide-range light distribution realized by the reflected light of the 1 st prism 11 (light distribution of the 1 st prism 11).

In the light guide plate 10 of the present embodiment, the diameter of the opening of the 2 nd prism 12 having a circular opening is smaller than the width of the opening of the 1 st prism 11 having a long groove.

The reflected light from the 2 nd prism 12 (the light distribution of the 2 nd prism 12) travels in the front direction or obliquely upward, and therefore has an effect that foreign matter such as dust is not easily visible, but if this effect is too large, it becomes a cause of strong light. Therefore, by making the diameter of the opening of the 2 nd prism 12 smaller than the width of the opening of the 1 st prism 11, it is possible to generate light distribution in obliquely downward and left-right directions by the 1 st prism 11 while suppressing strong light, and to make foreign matter inconspicuous by the 2 nd prism 12.

Further, since the diameter of the opening of the 2 nd prism 12 is smaller than the width of the opening of the 1 st prism 11, the 1 st reflecting surface 11a of the 1 st prism 11 is left as a flat surface without being covered with the 2 nd prism 12, and thus, a wide-range light distribution component in which light travels in the left-right direction is not easily broken, and glare when the light guide plate 10 is viewed obliquely can be suppressed.

In the light guide plate 10 of the present embodiment, when the 2 nd main surface 10d is viewed from the front, the total opening area of the 2 nd prisms 12 in the 1 st prism 11 is preferably 10-to-1 or less of the opening area of the 1 st prism 11.

With this configuration, even if the 2 nd prism 12 and the 1 st prism 11 are overlapped, the difference in the coverage ratio (aperture ratio difference) between the 1 st prism 11 and the 2 nd prism 12 can be made large, and therefore the area of the 1 st prism 11 (the 1 st reflecting surface 11a) can be sufficiently secured. This makes it possible to suppress strong light in a range where the light distribution in the left-right direction by the 1 st prism 11 is not broken, and effectively make foreign matter or damage inconspicuous by the light distribution in the front direction or obliquely upward direction by the 2 nd prism 12.

In the light guide plate 10 of the present embodiment, the control angle θ 1 of the 1 st prism 11 is preferably 10 ° or more and 40 ° or less.

When the control angle θ 1 of the 1 st prism 11 exceeds 40 °, the light distribution component of the light traveling in the front direction increases. On the other hand, if the control angle θ 1 of the 1 st prism 11 is smaller than 10 °, the irradiation area of the light emitted from the light guide plate 10 becomes too small.

Therefore, when the control angle θ 1 of the 1 st prism 11 is 10 ° or more and 40 ° or less, the reflected light of the 1 st prism 11 (the light distribution of the 1 st prism 11) is directed in the left-right direction and obliquely downward. Since the control angle θ 2 of the 2 nd prism 12 is larger than the control angle θ 1 of the 1 st prism 11, the reflected light from the 2 nd prism 12 (the light distribution of the 2 nd prism 12) is directed obliquely upward and in the front direction. As a result, the 1 st prism 11 can emit light over a wide range, and the 2 nd prism 12 can make foreign matter or damage inconspicuous.

Further, according to the light guide plate 10 of the present embodiment, in the 1 st prism 11, the center of at least 12 nd prism 12 overlaps with the center of the 1 st prism 11.

With this configuration, the 2 nd prism 12 exists at the apex of the 1 st prism 11, and thus the light guided in the light guide plate 10 efficiently reaches and is reflected by the 2 nd prism 12. As a result, the reflection efficiency of the 2 nd prism 12 is improved. Further, the traveling directions of the light reflected by the 1 st prism 11 and the 2 nd prism 12 can be made bilaterally symmetrical.

In the present embodiment, the 1 st prism 11 is a long groove, and the 2 nd prism 12 is a substantially conical shape, but the present invention is not limited thereto.

For example, as in the illumination device 1A and the light guide plate 10A shown in fig. 10 and 11, not only the 2 nd prism 12 but also the 1 st prism 11A may be substantially conical. However, the 1 st prism 11A has a substantially truncated cone shape in which the 2 nd prism 12 replaces the top of the cone. Fig. 10 is a diagram showing the structures of the light guide plate 10A and the light source 20 in the illumination device 1A according to modification 1 of embodiment 1, and fig. 11 is a partial sectional view of the light guide plate 10A. In fig. 10, (a) shows a side view of the light guide plate 10A and the light source 20, and (b) shows a cross-sectional view of the XB-XB line in (a). In addition, in FIG. 11, (a) and (b) are cross-sectional views of the line XIA-XIA and the line XIB-XIB in FIG. 10, respectively.

Alternatively, as in the illumination device 1B and the light guide plate 10B shown in fig. 12 and 13, not only the 1 st prism 11 but also the 2 nd prism 12B may be elongated. However, the length of the 2 nd prism 12B is preferably shorter than the length of the 1 st prism 11. Fig. 12 is a diagram showing the structures of a light guide plate 10B and a light source 20 in an illumination device 1B according to modification 2 of embodiment 1, and fig. 13 is a partial sectional view of the light guide plate 10B. In fig. 12, (a) shows a side view of the light guide plate 10B and the light source 20, and (B) shows a cross-sectional view of line XIIB-XIIB (a). In addition, in FIG. 13, (a) and (b) are cross-sectional views of XIIIA-XIIIA line and XIIIB-XIIIB line in FIG. 12, respectively.

Thus, as shown in fig. 10 to 13, the 1 st prism and the 2 nd prism may be of similar shapes. In this case, the same effect as that of the light guide plate 10 in embodiment 1 is also achieved. That is, even if foreign matter exists on the light guide plate 10 or the like or the light guide plate 10 is damaged, the foreign matter or damage can be made inconspicuous.

However, as shown in fig. 3 and 4, it is preferable that the 1 st prism 11 be a long groove and the 2 nd prism 12 be a substantially conical shape. In this way, even if the 2 nd prism 12 and the 1 st prism 11 are overlapped, the difference in the coverage of the 1 st prism 11 and the 2 nd prism 12 can be made large, and the area of the 1 st prism 11 (the 1 st reflecting surface 11a) can be easily secured. This makes it possible to suppress strong light by the light distribution of the 1 st prism 11 and effectively make foreign matter or damage inconspicuous by the light distribution of the 2 nd prism 12.

In the present embodiment, the 2 nd prism 12 is located inside the 1 st prism 11, and the 2 nd prism 12 is included in the 1 st prism 11, but the present invention is not limited thereto.

For example, as in the lighting device 1C and the light guide plate 10C shown in fig. 14 and 15, the 2 nd prism 12C may be exposed from the 1 st prism 11 when the 2 nd main surface 10d is viewed from the front. Fig. 14 is a diagram showing the structures of a light guide plate 10C and a light source 20 in a lighting device 1C according to modification 3 of embodiment 1, and fig. 15 is a partial sectional view of the light guide plate 10C. In fig. 14, (a) shows a side view of the light guide plate 10C and the light source 20, and (b) shows a cross-sectional view taken along line XIVB-XIVB of (a). In FIG. 15, (a), (b), and (c) are cross-sectional views of the lines XVA-XVA, XVB-XVB, and XVC-XVC in FIG. 14, respectively.

In this modification, the 1 st prism 11 is a long groove, and the 2 nd prism 12C is a substantially conical shape. In this case, in the present modification, when the 2 nd main surface 10d is viewed from the front, the diameter of the opening of the 2 nd prism 12C is larger than the width of the opening of the 1 st prism 11.

This modification also achieves the same effects as those of the light guide plate 10 in embodiment 1 described above. That is, even if foreign matter exists on the light guide plate 10 or the like or the light guide plate 10 is damaged, the foreign matter or damage can be made inconspicuous.

In this way, the 2 nd prism 12C need not be included in the 1 st prism 11, but as in embodiment 1 described above, the 2 nd prism 12C is preferably included in the 1 st prism 11. In this way, since the 1 st reflecting surface 11a is present over the entire circumference of the 1 st prism 11, even if the 2 nd prism 12C overlaps the 1 st prism 11, it is possible to suppress the destruction of the light distribution of the 1 st prism 11.

(embodiment mode 2)

Next, an illumination device 1D according to embodiment 2 will be described with reference to fig. 16 and 17. Fig. 16 is a diagram showing the structures of the light guide plate 10D and the light source 20 in the illumination device 1D according to embodiment 2. Fig. 17 is a partial sectional view of the light guide plate 10D. In fig. 16, (a) shows a side view of the light guide plate 10D and the light source 20, and (b) shows a cross-sectional view taken along line XVIB-XVIB in (a). In fig. 17, (a), (b), and (c) are cross-sectional views of the lines XVIIA to xviiia, xviiib to xviiib, and xviiic to xviiic in fig. 16, respectively.

The lighting device 1D of the present embodiment differs from the lighting device 1 of embodiment 1 in the structure of the light guide plate 10D. Specifically, according to the light guide plate 10 of embodiment 1 described above, only 1 of the 1 st prisms 11 is formed with the 2 nd prisms 12, whereas according to the light guide plate 10D of the present embodiment, a plurality of the 2 nd prisms 12 are formed with the 1 st prisms 11.

Specifically, as shown in fig. 16 and 17, 2 nd prisms 12 are formed on each 1 st prism 11. The 2 nd prisms 12 in each 1 st prism 11 are identical in size and shape to each other, and are formed at bilaterally symmetrical positions along the longitudinal direction of the 1 st prism 11, which is a long groove.

As described above, according to the light guide plate 10D of the present embodiment, as with the light guide plate 10 of embodiment 1, the 2 nd prism 12 having the control angle θ 2 larger than the control angle θ 1 of the 1 st prism 11 is formed so as to overlap the 1 st prism 11 in which a plurality of the 1 st prisms are two-dimensionally formed on the 2 nd main surface 10D.

This embodiment also achieves the same effects as those of the light guide plate 10 of embodiment 1. That is, even if foreign matter exists on the light guide plate 10D or the like or the light guide plate 10D is damaged, the foreign matter or damage can be made less noticeable.

In the present embodiment, a plurality of 2 nd prisms 12 are formed in the 1 st prism 11.

This achieves the following effects. In order to adjust the ratio of the light distribution of the 1 st prism 11 and the ratio of the light distribution of the 2 nd prism 12, it is necessary to adjust the difference in the coverage of the 1 st prism 11 and the 2 nd prism 12. In this case, the coverage difference can be adjusted by changing the size of the 1 st prism 11 or the 2 nd prism 12. However, in this case, a method for performing processing for changing the size of the 1 st prism 11 or the 2 nd prism 12 is additionally required.

In contrast, as in the present embodiment, by forming a plurality of 2 nd prisms 12 in the 1 st prisms 11, the difference in the coverage ratio between the 1 st prisms 11 and the 2 nd prisms 12 can be easily adjusted according to the number of the 2 nd prisms 12. This makes it possible to easily adjust the ratio of the light distribution of the 1 st prism 11 and the ratio of the light distribution of the 2 nd prism 12, and thus to easily obtain the illumination device 1D having a desired light distribution characteristic. For example, it is possible to suppress glare and to make foreign substances or damage present in the light guide plate 10D less noticeable. In addition, since only 1 prism 12 needs to be processed, the time required for prism design and prism processing can be shortened.

In the present embodiment, 2 nd prisms 12 are formed in 1 st prism 11, but the present invention is not limited thereto. For example, 3 or more 2 nd prisms 12 may be formed in 1 st prism 11.

In the present embodiment, the 2 nd prisms 12 are formed to be aligned along the longitudinal direction of the 1 st prism 11, but the present invention is not limited thereto.

(embodiment mode 3)

Next, an illumination device 1E according to embodiment 3 will be described with reference to fig. 18 and 19. Fig. 18 is a diagram showing the structures of the light guide plate 10E and the light source 20 in the illumination device 1E according to embodiment 3. Fig. 19 is a partial sectional view of the light guide plate 10E. In fig. 18, (a) shows a side view of the light guide plate 10E and the light source 20, and (b) shows a cross-sectional view along line XVIIIB-XVIIIB of (a). In FIG. 19, (a), (b), (c), and (d) are cross-sectional views of the XIXA-XIXA line, XIXB-XIXB line, XIXC-XIXC line, and XIXD-XIXD line of FIG. 18, respectively.

The illumination device 1E of the present embodiment differs from the illumination device 1D of embodiment 2 in the structure of the light guide plate 10E. Specifically, according to the light guide plate 10D of embodiment 2, 1 type of the 2 nd prisms 12 are formed in each 1 st prism 11. That is, although the 2 nd prism 12 is formed in plural, the control angle θ 2 of each 2 nd prism 12 is the same. In contrast, according to the light guide plate 10E of the present embodiment, there are a plurality of types of control angles of the plurality of prisms added to the 1 st prism 11.

Specifically, as shown in fig. 18 and 19, the light guide plate 10E includes 1 or more concave 3 rd prisms 13 formed to overlap with the 1 st prism 11 and the 2 nd prism 12, respectively, in the 1 st prism 11 in addition to the 1 st prism 11 and the 2 nd prism 12. The control angle θ 3 of the 3 rd prism 13 is different from each of the control angle θ 1 of the 1 st prism 11 and the control angle θ 2 of the 2 nd prism 12. In the present embodiment, the control angle θ 3 of the 3 rd prism 13 is larger than the control angle θ 1 of the 1 st prism 11 and smaller than the control angle θ 2 of the 2 nd prism 12(θ 1 < θ 3 < θ 2).

The 3 rd prism 13 is a sub-prism for adjusting the light distribution of the light guide plate 10E by the 1 st prism 11 as a main prism, similarly to the 2 nd prism 12. When the 2 nd main surface 10d is viewed from the front, the 3 rd prism 13 is preferably located inside the 1 st prism 11. That is, the 3 rd prism 13 is preferably included in the 1 st prism 11. Therefore, when the 2 nd main surface 10d is viewed from the front, the opening area of the 3 rd prism 13 is smaller than that of the 1 st prism 11. In addition, the opening area of the 3 rd prism 13 is larger than that of the 2 nd prism 12. For example, the 3 rd prism 13 is substantially conical in shape like the 2 nd prism 12. Therefore, when the 2 nd main surface 10d is viewed from the front, the opening shape of the 3 rd prism 13 is circular.

As shown in fig. 19 (c), the 1 st prism 11, the 2 nd prism 12, and the 3 rd prism 13 are formed in this order along the depth direction at the portion where the 1 st prism 11, the 2 nd prism 12, and the 3 rd prism 13 overlap. That is, the base of the 1 st prism 11 is made deeper to form the 3 rd prism 13, and the base of the 3 rd prism 13 is made deeper to form the 2 nd prism 12. Specifically, the 3 rd prism 13 is formed to protrude in a protruding shape in the depth direction from the bottom of the 1 st prism 11, and the 2 nd prism 12 is formed to protrude in a protruding shape in the depth direction from the bottom of the 1 st prism 11.

Therefore, in the portion where the 1 st prism 11, the 2 nd prism 12, and the 3 rd prism 13 overlap, the 1 st reflection surface 11a of the 1 st prism 11 is formed on the 2 nd main surface 10d side, the 3 rd reflection surface 13a of the 3 rd prism 13 is formed in the depth direction continuously with the 1 st reflection surface 11a, and the 2 nd reflection surface 12a of the 2 nd prism 12 is formed in the depth direction continuously with the 3 rd reflection surface 13 a.

As described above, in the light guide plate 10E of the present embodiment, as in the light guide plate 10 of embodiment 1, the 2 nd prism 12 having the control angle θ 2 larger than the control angle θ 1 of the 1 st prism 11 is formed so as to overlap the 1 st prism 11 in which a plurality of the 1 st prisms are two-dimensionally formed on the 2 nd main surface 10 d.

This embodiment also achieves the same effects as those of the light guide plate 10 of embodiment 1. That is, even if foreign matter exists on the light guide plate 10E or the like or the light guide plate 10E is damaged, the foreign matter or damage can be made less noticeable.

Further, the light guide plate 10E of the present embodiment includes 1 or more concave 3 rd prisms 13 formed to overlap with the 1 st prism 11 and the 2 nd prism 12, respectively, among the 1 st prism 11. The control angle θ 3 of the 3 rd prism 13 is different from the control angle θ 1 of the 1 st prism 11 and the control angle θ 2 of the 2 nd prism 12, respectively.

By forming 3 types of reflection prisms having different control angles in a superimposed manner, light can be emitted in three dimensions in more directions without impairing the appearance of the light guide plate, as compared with the case where only the 1 st prism 11 is formed.

In the present embodiment, the 1 rd 3 rd prism 13 is formed to overlap the 1 st prism 11 and the 2 nd prism 12, but the present invention is not limited thereto. For example, another sub-prism having a further different control angle may be formed together with the 3 rd prism 13 so as to overlap the 1 st prism 11 and the 2 nd prism 12.

In the present embodiment, the 3 rd prism 13 is added to the 1 st prism 11 and the 2 nd prism 12, but it is also conceivable to form a plurality of types (that is, θ 2) having different control angles θ 2 from each other for the 1 st prism 11₁，θ2₂，θ2₃Prism 2 (c) · prism 12).

In the present embodiment, the 2 nd prism 12 and the 3 rd prism 13 are added to the center of the 1 st prism 11 of the light guide plate 10D of embodiment 2, and the number of the 2 nd prisms 12 is 3, but the present invention is not limited thereto. The 2 nd prism 12 may be only the central 1 of the 3. That is, the 3 rd prism 13 may be added to the light guide plate 10 of embodiment 1.

(embodiment mode 4)

Next, an illumination device 1F according to embodiment 4 will be described with reference to fig. 20 and 21. Fig. 20 is a diagram showing the structures of the light guide plate 10F and the light source 20 in the illumination device 1F according to embodiment 4. Fig. 21 is a partial sectional view of the light guide plate 10F. In fig. 20, (a) shows a side view of the light guide plate 10F and the light source 20, and (b) shows a cross-sectional view taken along line XXB-XXB of (a).

The lighting device 1F of the present embodiment is different from the lighting device 1 of embodiment 1 in the structure of the light guide plate 10F. Specifically, while the light guide plate 10 according to embodiment 1 does not have the reflection prism formed on the 1 st main surface 10c, the light guide plate 10F according to the present embodiment has the reflection prism formed not only on the 2 nd main surface 10d but also on the 1 st main surface 10 c.

Specifically, as shown in fig. 20 and 21, the light guide plate 10F of the present embodiment further includes the 4 th prism 14 formed on the 1 st main surface 10 c. The control angle θ 4 of the 4 th prism 14 is larger than the control angle θ 1 of the 1 st prism 11. In the present embodiment, the control angle θ 4 of the 4 th prism 14 is the same as the control angle θ 2 of the 2 nd prism 12 formed on the 2 nd main surface 10 d. Thus, the 4 th reflecting surface 14a of the 4 th prism 14 is the same as the 2 nd reflecting surface 12a of the 2 nd prism 12.

As described above, in the light guide plate 10F of the present embodiment, as in the light guide plate 10 of embodiment 1, the 2 nd prism 12 having the control angle θ 2 larger than the control angle θ 1 of the 1 st prism 11 is formed so as to overlap the 1 st prism 11 in which the plurality of 1 nd prisms 11 are two-dimensionally formed on the 2 nd main surface 10 d.

This embodiment also achieves the same effects as those of the light guide plate 10 of embodiment 1. That is, even if foreign matter exists on the light guide plate 10F or the like or the light guide plate 10F is damaged, the foreign matter or damage can be made less noticeable.

The light guide plate 10F of the present embodiment further includes a 4 th prism 14 formed on the 1 st main surface 10 c. That is, the reflection prisms are formed on both the 1 st main surface 10c and the 2 nd main surface 10d of the light guide plate 10F. Further, the control angle θ 4 of the 4 th prism 14 is larger than the control angle θ 1 of the 1 st prism 11.

As a result, as shown in fig. 21, even when the light guide plate 10F is viewed from the 1 st main surface 10c side or the 2 nd main surface 10d side, foreign matters or damage of the light guide plate 10F can be made less conspicuous.

In the present embodiment, the control angle θ 4 of the 4 th prism 14 is the same as the control angle θ 2 of the 2 nd prism 12, but the control angle θ 4 of the 4 th prism 14 may be different from the control angle θ 2 of the 2 nd prism 12. The shape and size of the 4 th prism 14 are the same as those of the 2 nd prism 12, but the utility model is not limited thereto.

In the present embodiment, only 1 type of reflection prism, i.e., the 4 th prism 14, is formed on the 1 st main surface 10c, but the present invention is not limited thereto. For example, a plurality of types of reflection prisms having different control angles may be formed on the 1 st main surface 10c in a superimposed manner.

Specifically, as shown in fig. 22, the 4 th prism 14 and the 5 th prism 15 may be formed on the 1 st main surface 10 c. In fig. 22, the structure of the 5 th prism 15 is the same as that of the 1 st prism 11 formed on the 2 nd main surface 10 d. Thus, the control angle θ 5 of the 5 th prism 15 is the same as the control angle θ 1 of the 1 st prism 11. That is, the inclination angle of the 5 th reflecting surface 15a of the 5 th prism 15 is the same as the inclination angle of the 1 st reflecting surface 11a of the 1 st prism 11. The shape and size of the 5 th prism 15 are the same as those of the 1 st prism 11.

In fig. 22, the 4 th prism 14 and the 5 th prism 15 are formed to overlap each other. That is, the light reflection structures having the same structure in which 2 kinds of reflection prisms having different control angles are superimposed are formed on the 1 st main surface 10c and the 2 nd main surface 10d of the light guide plate. Accordingly, the light distribution on the 1 st main surface 10c side and the 2 nd main surface 10d side can be made the same, and therefore, even when viewed from either the 1 st main surface 10c side or the 2 nd main surface 10d side, foreign matter or damage of the light guide plate can be made less noticeable.

In fig. 22, the light reflecting structure on the 1 st main surface 10c side and the light reflecting structure on the 2 nd main surface 10d side are formed differently from each other in the cross-sectional view of the light guide plate, but the utility model is not limited thereto. That is, the light reflecting structure on the 1 st main surface 10c side and the light reflecting structure on the 2 nd main surface 10d side are formed so as not to overlap when the light guide plate is viewed from the front. For example, when the light guide plate is viewed from the front, the light reflecting structure on the 1 st main surface 10c side and the light reflecting structure on the 2 nd main surface 10d side may be formed to overlap each other.

(embodiment 5)

Next, an illumination device 1G according to embodiment 5 will be described with reference to fig. 23. Fig. 23 is a diagram showing the structures of the light guide plate 10 and the light source 20G in the illumination device 1G according to embodiment 5. Fig. 23 shows a side view of the light guide plate 10 and the light source 20G (a), and a cross-sectional view taken along line XXIIIB-XXIIIB of (a).

The lighting device 1G of the present embodiment differs from the lighting device 1 of embodiment 1 in the configuration of the light source 20G. Specifically, the light source 20 in embodiment 1 is an SMD type LED module using an SMD type LED element as the light emitting element 22, and the light source 20G in the present embodiment is a cob (chip On board) type LED module in which the light emitting element 22G itself is an LED chip (bare chip).

Specifically, as shown in fig. 23, the light source 20G includes a substrate 21, a light emitting element 22G as an LED chip directly mounted on the substrate 21, and a sealing member 23G sealing the light emitting element 22G.

In the present embodiment, a plurality of light emitting elements 22G are mounted on the substrate 21. Specifically, the light emitting elements 22G are mounted in a row along the longitudinal direction of the substrate 21. The plurality of light emitting elements 22G are collectively sealed by the sealing member 23G. Therefore, the sealing member 23G is formed linearly along the longitudinal direction of the substrate 21.

The light source 20G emits white light. In this case, each of the light emitting elements 22G is, for example, a blue LED chip that emits blue light, and the sealing member 23G is a silicone resin (phosphor-containing resin) containing a yellow phosphor such as YAG. Thus, white light is emitted from the sealing member 23G by light emission of the light emitting element 22G. In the present embodiment, since the sealing member 23G is formed linearly, white light continuing linearly is emitted from the sealing member 23G. That is, the light source 20G is a linear light source that emits linear white light.

The light source 20G configured as described above is disposed to face the 1 st end face 10a of the light guide plate 10. Specifically, the light source 20G is disposed such that the longitudinal direction of the light source 20G coincides with the longitudinal direction of the 1 st end face 10 a. Thereby, the light source 20G emits light continuously in a long shape in the longitudinal direction of the 1 st end face 10 a.

As described above, the illumination device 1G of the present embodiment uses the same light guide plate 10 as the light guide plate 10 in embodiment 1.

This embodiment also achieves the same effects as those of the light guide plate 10 of embodiment 1. That is, even if foreign matter exists in the light guide plate 10 or the light guide plate 10 is damaged, the foreign matter or damage can be made less noticeable.

Further, the illumination device 1G of the present embodiment uses the light source 20G that emits light continuously in a long shape along the longitudinal direction of the 1 st end surface 10a of the light guide plate 10.

By making the light emitted from the light source 20G linear, instead of being point-shaped, it is possible to suppress the bright line (vertical line) pattern from being generated in the visual line direction by the light reflected by the 1 st prism 11 and the 2 nd prism 12. This can improve the appearance quality of the light guide plate 10 at the time of lighting.

(embodiment mode 6)

Next, an illumination device 1H according to embodiment 6 will be described with reference to fig. 24. Fig. 24 is a diagram showing the structures of the light guide plate 10, the light source 20, and the light absorber 50 in the lighting device 1H according to embodiment 6. Fig. 24 shows a side view of the light guide plate 10, the light source 20, and the light absorber 50 in (a), and a cross-sectional view taken along line XXIVB-XXIVB in (a).

The illumination device 1H of the present embodiment further includes a light absorbing material 50 in comparison with the illumination device 1 of embodiment 1.

The light absorbing member 50 is formed at the 2 nd end surface 10b of the light guide plate 10. In the present embodiment, the light absorbing material 50 covers the entire 2 nd end surface 10 b. The light absorbing material 50 is optically closely attached to the 2 nd end surface 10 b. The light absorber 50 is, for example, a coating film made of a material that absorbs light. In this case, the 2 nd end surface 10b of the light guide plate 10 is coated with a coating material and cured, whereby the light absorbing material 50 formed of a coating film can be formed in close contact with the 2 nd end surface 10 b. The light absorbing material 50 may be a belt-like belt member. In this case, the light absorbing material 50 can be bonded to the 2 nd end surface 10b of the light guide plate 10 by the adhesive.

The light absorbing material 50 is formed by, for example, using a material (for example, a resin material) having substantially the same refractive index as the light guide plate 10 as a base material, and an additive (for example, a black additive) having a light absorbing function such as carbon is added to the base material. The refractive index of the base material of the light absorber 50 may be different from the refractive index of the light guide plate 10.

As described above, the lighting device 1H of the present embodiment also uses the same light guide plate 10 as the light guide plate 10 in embodiment 1 described above.

This embodiment also achieves the same effects as those of the light guide plate 10 in embodiment 1. That is, even if foreign matter exists in the light guide plate 10 or the light guide plate 10 is damaged, the foreign matter or damage can be made less noticeable.

Further, in the lighting device 1H of the present embodiment, the light absorbing material 50 is formed on the 2 nd end surface 10b of the light guide plate 10. That is, the light absorbing member 50 is formed on the end surface on the opposite side to the light source 20 side.

This can suppress the light distribution of the light guide plate 10 from being broken or the glare from being emitted in the line of sight direction of the user due to the light reaching the 2 nd end face 10b among the light entering the light source 20 in the light guide plate 10 from the 1 st end face 10 a. This is explained below.

In the case where the light absorbing member 50 is not formed on the 2 nd end surface 10b of the light guide plate 10, a part of the light reaching the 2 nd end surface 10b is totally reflected by the 2 nd end surface 10b, returns to the 1 st end surface 10a side (light source 20 side), and is guided inside the light guide plate 10. At this time, the light reflected by the 2 nd end surface 10b may be reflected by the 1 st prism 11 or the 2 nd prism 12, and the light distribution of the light guide plate 10 may be broken or strong light may be emitted in the line of sight direction of the user.

On the other hand, since the light absorbing material 50 is formed on the 2 nd end surface 10b of the light guide plate 10, the light absorbing material 50 can absorb the light reaching the 2 nd end surface 10b, and thus the light reaching the 2 nd end surface 10b can be prevented from being reflected by the 2 nd end surface 10b and returning to the 1 st end surface 10a side (light source 20 side). As a result, it is possible to suppress the light distribution of the light guide plate 10 from being broken or the strong light from being emitted in the line of sight direction of the user. For example, the 1 st prism 11 can realize illumination light distributed in a wide range for non-glare purposes.

(modification example)

The light guide plate, the light guide plate system, and the like of the present invention have been described above based on embodiments 1 to 6, but the present invention is not limited to the above embodiments 1 to 6.

For example, in embodiments 1 to 6, the connection portion between the 1 st reflecting surface 11a of the 1 st prism 11 and the 2 nd reflecting surface 12a of the 2 nd prism 12 is bent, but the present invention is not limited thereto. For example, as in the light guide plate 10I shown in fig. 25, a connection portion between the 1 st reflection surface 11a of the 1 st prism 11 and the 2 nd reflection surface 12a of the 2 nd prism 12 may be smoothly curved.

As in the light guide plate 10J shown in fig. 26, the connecting portion between the 1 st reflecting surface 11a of the 1 st prism 11 and the 2 nd reflecting surface 12a of the 2 nd prism 12 may be curved with an inflection point. For example, the connecting portion between the 1 st reflecting surface 11a and the 2 nd reflecting surface 12a may have a slightly raised shape.

Further, as in the light guide plate 10K shown in fig. 27, not only the connection portion between the 1 st reflection surface 11a of the 1 st prism 11 and the 2 nd reflection surface 12a of the 2 nd prism 12, but also the connection portion between the 2 nd main surface 10d and the 1 st reflection surface 11a of the 1 st prism 11 may be curved with an inflection point. For example, the connecting portion between the 2 nd main surface 10d and the 1 st reflecting surface 11a may have a slightly raised shape.

In addition, in the above embodiments 1 to 6, the light source 20 is disposed above the light guide plate, but is not limited thereto. For example, the light source 20 may be disposed below the light guide plate.

In embodiments 1 to 6, the light sources 20 and 20G are formed of LEDs, but the present invention is not limited thereto. For example, the light sources 20 and 20G may be solid-state light emitting elements other than LEDs, such as semiconductor lasers and organic el (electro luminescence). As the light source 20, an existing lamp such as a fluorescent lamp or a high-luminance lamp may be used.

In embodiments 1 to 6, the case where the light guide plates 10 to 10K are used for the pole lamp has been described, but the present invention is not limited thereto. For example, the light guide plates 10 to 10K can be applied to any lighting device other than a pole light such as a ceiling light (ceiling light).

In embodiments 1 to 6, the case where the light guide plates 10 to 10K are applied to the lighting device has been described, but the utility model is not limited thereto. The present invention can also be applied to a light guide plate system having a light guide plate.

In addition, the present invention includes a configuration obtained by applying various modifications to the above-described embodiment, and a configuration in which the constituent elements and functions of the above-described embodiment are arbitrarily combined without departing from the scope of the present invention.

Claims (14)

1. A light guide plate having a 1 st end face on which light emitted from a light source enters, a 1 st main face on which light incident from the 1 st end face exits, and a 2 nd main face opposite to the 1 st main face,

comprising:

a plurality of concave 1 st prisms formed two-dimensionally on the 2 nd main surface; and

1 or more concave 2 nd prisms formed to overlap at least one of the 1 st prisms,

the control angle of the 2 nd prism is larger than that of the 1 st prism.

2. The light guide plate according to claim 1,

when the 2 nd main surface is viewed from the front, the 2 nd prism is positioned inside the 1 st prism.

3. The light guide plate according to claim 1,

the 1 st prism is an elongated slot extending in a direction intersecting the optical axis of the light source.

4. The light guide plate according to claim 3,

when the 2 nd main surface is viewed from the front, the opening shape of the 2 nd prism is a circular shape.

5. The light guide plate according to claim 4,

the diameter of the opening of the 2 nd prism is smaller than the width of the opening of the 1 st prism.

6. The light guide plate according to any one of claims 3 to 5,

when the 2 nd main surface is viewed from the front, the total opening area of the 2 nd prism in 1 of the 1 st prisms is less than or equal to 1/10 of the opening area of the 1 st prism.

7. The light guide plate according to any one of claims 1 to 5,

the control angle of the 1 st prism is 10 ° or more and 40 ° or less.

8. The light guide plate according to any one of claims 1 to 5,

in the 1 st prism, the 2 nd prism is formed in plural.

9. The light guide plate according to any one of claims 1 to 5,

1 or more concave 3 rd prisms formed to overlap with the 1 st prism and the 2 nd prism respectively among the 1 st prisms,

the control angle of the 3 rd prism is different from the control angle of the 1 st prism and the control angle of the 2 nd prism.

10. The light guide plate according to any one of claims 1 to 5,

in the 1 st prism, at least the center of the 1 nd prism overlaps the center of the 1 st prism.

11. The light guide plate according to any one of claims 1 to 5,

further comprises a 4 th prism formed on the 1 st main surface,

the control angle of the 4 th prism is larger than that of the 1 st prism.

12. The light guide plate according to any one of claims 1 to 5,

and a light absorbing member formed on the 2 nd end surface opposite to the 1 st end surface.

13. A light guide plate system is characterized in that,

the disclosed device is provided with:

the light guide plate according to any one of claims 1 to 12; and

and a light source for emitting light incident on the 1 st end surface of the light guide plate.

14. The light guide plate system as claimed in claim 13,

the 1 st end face is long-strip-shaped,

the light source is disposed opposite to the 1 st end surface, and emits light continuously in a long shape along a longitudinal direction of the 1 st end surface.

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