JP2002098838A - Rod-like light guide body, linear illumination device which uses the same and surface illumination device which uses the linear illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost and the number of assembling processes and to improve the productivity by improving the use efficiency of incident light and producing uniform viewing angle characteristics of outgoing light from the outgoing face without depending on the position in a linear light guide body. SOLUTION: The rod-like light guide body 10 has an entrance face 11 where light emitting from a point light source 50 enters, an outgoing face 13 which is perpendicular to the entrance face 11 and where the light entering the entrance face 11 outgoes as linear light, and a pattern face 12 where one side line of the entrance face 11 and one side line of the outgoing face 13 are connected and a plurality of grooves 21 are formed. The plurality of grooves 21 are regularly arranged on the pattern face 12. The angle made by the grooves 21 and one side line of the outgoing face 13 in the side of the point light source 103 is controlled to from 35 deg. to 55 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rod-shaped light guide for converting a point light source into a linear light source, a linear illuminator using the same, and a planar illuminator using the linear illuminator.

[0002]

2. Description of the Related Art As a linear lighting device for converting a point light source such as a light emitting diode (LED) light source into a linear light source by a light guide, the one shown in FIG. 16 is known. This linear lighting device is provided with both end surfaces 21 of a rod-shaped light guide 210.
Point light sources 250, 250 are arranged at 1, 211, respectively. The light exit surface 213 on one side surface of the light guide 210 in the longitudinal direction is provided.
For example, a V-shaped groove 225 is formed on the reflection surface 216 facing
There is known a method of forming a plurality of light guides in the longitudinal direction of the rod-shaped light guide 210. The rod-shaped light guide 210 is provided on the light exit surface 21.
3. reflective surface 216 and both side surfaces 212 orthogonal to these surfaces;
215 and a square pole shape. In this method, a light beam 290G, which is a part of the light beam incident on the rod-shaped light guide 210 from the point light source 250, directly reaches the slope 226 of the V-shaped groove 225 provided on the reflection surface 216, and the slope 226. The light reaches the light exit surface 213 at an angle equal to or less than the critical angle of the light exit surface 213 and exits from the light exit surface 213. Further, another part of the incident light beam is repeatedly reflected until the angle between the light exit surface 213 and the reflection surface 216 becomes equal to or smaller than the critical angle. In such a principle, the V-shaped groove 225
By setting the pitch or depth distribution to an appropriate value, the light amount distribution of the light emitted from the light emitting surface 213 can be made substantially uniform, and as a result, a linear light source can be obtained.

A planar illumination device using a light source composed of a point light source and a linear light guide as a linear light source of an illumination device of a liquid crystal display device is described in Japanese Patent Application Laid-Open No. 2000-11723. I have.

In the light source described in this publication, a point light source is arranged close to an end of a light guide on which an optical path changing means is formed. The optical path changing means includes, for example, a groove having a substantially triangular cross section and a flat portion formed between the grooves. As one example of the optical path changing means, the distance between one groove and the adjacent groove is constant,
The figure shows that the cut depth of the groove is set to gradually increase as the distance from the point light source increases. Further, as another example of the optical path changing means, there is shown an optical path changing means in which the cut depth of the above-mentioned groove is made constant, and the interval of forming the groove is gradually narrowed as the distance from the point light source increases. Have been.

Further, the spread illuminating device described in this publication uses a light source having a configuration in which two point light sources are arranged at both ends of a linear light guide, each having a point light source arranged close to each other. In addition, there is shown one in which the surfaces of the light guide are arranged to face each other along one end surface of the transparent substrate.

By the way, in the above-described configuration, particularly in the configuration shown in FIG. 16, the rod-shaped light guide 210 is formed in a rectangular cross section having a uniform thickness.
Most of the incident light that is parallel to the optical axis of the incident light from the incident surface 211 and incident from the incident surface 211 is not irradiated to the reflecting surface 216. That is, light 290H that is perpendicular to the incident surface 211 and that is higher than the height of the V-shaped groove 225 is
There is a disadvantage that the light utilization efficiency of the incident light is reduced without reaching the reflection surface 216.

The light obliquely incident on the incident surface 211 repeats reflection between the light emitting surface 213, the reflecting surface 216, and both side surfaces.
The light reaches the light source side slope 226 of the V-shaped groove 225, and is reflected by the light source side slope 226, reaches the light emission surface 213 at an angle equal to or less than the critical angle of the light emission surface 213, and is emitted from the light emission surface 213.

FIG. 17 shows a configuration of a planar illumination device using the linear illumination device shown in FIG. As shown in FIG. 17, the light guide 21 of the linear light source device is provided on one end face side of the light guide plate 280.
The light emitting surface 213 of 0 is arranged in proximity. The light guide 210 has a light guide plate 280 formed by a reflector 270 having a reflection function.
Is held on one side end face.

[0009]

However, FIG.
Also, as shown in FIG. 17, particularly when the width Q of the side surfaces 212 and 215 is longer than the height P of the light emitting surface 213 in the cross-sectional shape of the rod-shaped light guide 210, the V-shaped groove 225 is larger than the cross-sectional area.
The area occupied by the height of the object becomes smaller. Therefore, the light emitting surface 2
13, the light which is repeatedly reflected between the reflection surface 216 and the side surfaces 212 and 215 is transmitted through the V-shaped groove 2 provided on the reflection surface 216.
25, the ratio of reaching the light source side inclined surface 226 is low, and the number of light rays that do not reach the reflecting surface 216 and pass through the surface opposite to the incident surface 211 increases, so that the light use efficiency of incident light is further reduced. .

Also, the light source 250 having the highest light intensity
The angle of incidence of the V-shaped groove 225 on the light source side slope 226 at a location near the entrance surface 211 directly reaching from the
Light source side slope 22 of V-shaped groove 225 at a location far from 1
6, the viewing angle characteristics of the light emitted from the light exit surface 213 differ depending on the location, as shown in FIG. In FIG. 18, the angular distribution of light rays emitted from the rod-shaped light guide 210 is schematically shown at three points near the left incident surface 211, the center, and near the right incident surface 211 in the drawing. The angular distribution of the outgoing light beam also exists in the portion.

In order to use such a linear light source as a light source for a light guide plate, for example, as shown in FIG. 17, a diffusion sheet 261 and a lens sheet 262 must be arranged on the light exit surface 213 side for correction. However, this has led to an increase in costs and a decrease in productivity due to an increase in the number of assembly steps.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to improve the light use efficiency of incident light.

Further, the present invention reduces the cost, reduces the number of assembling steps, and improves the productivity by making the viewing angle characteristics of the light emitted from the light emitting surface depending on the location of the linear light guide uniform. The purpose is to achieve it.

[0014]

According to the first aspect of the present invention, a light incident surface on which light emitted from a point light source is incident;
A light exit surface that is orthogonal to the light entrance surface and emits light incident on the light entrance surface as linear light, a surface where one side of the light entrance surface and one side of the light exit surface are connected to each other. A pattern surface on which a plurality of grooves are formed, a surface facing the light emitting surface, and a surface facing the pattern surface, wherein the pattern surface has the plurality of grooves arranged regularly, The angle between the groove and one side of the light exit surface on the side of the point light source is 35 °.
A rod-shaped light guide formed at an angle of from about 55 ° to about 55 °.

According to the first aspect, the main component light from the point light source is reflected by the groove, and the light is emitted from the light emitting surface in a direction substantially perpendicular to the light emitting surface, so that the light use efficiency of the incident light is improved. Can be planned. Further, the viewing angle characteristics of the light emitted from the light emitting surface depending on the location of the linear light guide can be made uniform.

According to a seventh aspect of the present invention, the first light incident surface on which the light emitted from the first point light source is incident, the first light incident surface,
A second light-entering surface opposed to the light-entering surface, on which light emitted from a second point light source is incident, and a light orthogonal to the plurality of light-entering surfaces and incident on the plurality of light-entering surfaces. A light-emitting surface that emits as linear light, a surface facing the light-emitting surface, and having an upper edge of the plurality of light-entering surfaces and an upper edge of the light-emitting surface, are regularly arranged, and have an upper edge of the light-emitting surface. A first pattern surface having a plurality of grooves formed at an angle of 35 ° to 55 ° on the first point light source side, and a first pattern surface facing the first pattern surface, regularly arranged, and A rod-shaped light guide, comprising: a second pattern surface having a plurality of grooves formed at an angle of 35 ° to 55 ° with respect to a second point light source side with respect to a base.

According to the seventh aspect, the light emitted from the light emitting surface can have high brightness.

The present invention according to claim 11 provides a point light source,
A light incident surface on which light emitted from the point light source is incident,
In a linear lighting device including a light exit surface that is orthogonal to the light entrance surface and emits light incident on the light entrance surface as linear light, and a rod-shaped light guide, the rod-shaped light guide includes: One side of the light entrance surface and one side of the light exit surface are connected surfaces, and this surface has a pattern surface on which a plurality of grooves are formed, and the plurality of grooves are regularly formed on the pattern surface. An angle formed between the groove and one side of the light emitting surface on the side of the point light source is formed at 35 ° to 55 °.

According to the eleventh aspect, the main component light from the point light source is reflected by the groove, and the light is emitted from the light emitting surface in a direction substantially perpendicular to the light emitting surface, so that the light use efficiency of the incident light is improved. Can be planned. Further, the viewing angle characteristics of the light emitted from the light emitting surface depending on the location of the linear light guide can be made uniform. Further, since a diffusion sheet and a lens sheet are not required, the cost and the number of assembling steps can be reduced, and the productivity of the linear lighting device can be improved.

According to a twelfth aspect of the present invention, there is provided a first point light source, a second point light source, a first light incident surface on which light emitted from the first point light source is incident, and A second light incident surface on which light emitted from the two-point light source is incident;
A light exit surface that is orthogonal to the light entrance surface and emits light incident on the first and second light entrance surfaces as linear light, and a rod-shaped light guide having:
In the linear lighting device provided with, the rod-shaped light guide has an upper side of the plurality of light-entering surfaces and an upper side of the light-emitting surface, and is regularly arranged, and is arranged in a first direction with the upper side of the light-emitting surface.
A first pattern surface having a plurality of grooves formed at an angle of 35 ° to 55 ° on the side of the point light source;
A second pattern surface having a plurality of grooves which are regularly arranged to face the pattern surface and have an angle formed on the second point light source side with respect to the bottom of the light emitting surface on the second point light source side; , Is provided.

According to the twelfth aspect, it is possible to provide a linear illuminating device capable of increasing the intensity of light emitted from the light emitting surface.

According to a thirteenth aspect of the present invention, in the planar illuminating device, a linear illuminating device including a point light source and a rod-shaped light guide is disposed near a side surface of the planar light guide plate made of a translucent material. The planar light guide plate is a reflecting surface that intersects the incident surface at which light emitted from the light emitting surface of the linear lighting device enters at 80 ° to 100 ° and reflects the light incident on the incident surface. And an emission surface facing the reflection surface and emitting light reflected from the reflection surface as planar light,
The rod-shaped light guide includes a light incident surface on which light emitted from the point light source is incident, and a light emitting surface orthogonal to the light incident surface and emitting light incident on the light incident surface as linear light. And a pattern surface on which one side of the light entrance surface and one side of the light exit surface are connected, and a pattern surface on which a plurality of grooves are formed, wherein the pattern surface includes the plurality of grooves. Are arranged regularly,
An angle formed between the groove and one side of the light exit surface on the side of the point light source is formed at 35 ° to 55 °.

According to the thirteenth aspect, the main component light from the point light source is reflected by the groove, and the light is emitted from the light emitting surface in a direction substantially perpendicular to the light emitting surface, so that the light use efficiency of the incident light is improved. Can be planned. Further, the viewing angle characteristics of the light emitted from the light emitting surface depending on the location of the linear light guide can be made uniform. Further, since a diffusion sheet and a lens sheet are not required, the cost and the number of assembling steps can be reduced, and the productivity of the spread illuminating device can be improved.

According to a fourteenth aspect of the present invention, there is provided a planar light guide plate made of a translucent material, wherein a linear lighting device comprising first and second point light sources and a rod-shaped light guide is arranged close to the side surface. In the planar lighting device, the planar light guide plate intersects the incident surface at which light emitted from the light exit surface of the linear lighting device is incident with the incident surface at 80 ° to 100 °, and is incident on the incident surface. The rod-shaped light guide includes a reflecting surface that reflects light, and an emitting surface that faces the reflecting surface and emits light reflected from the reflecting surface as planar light. A first light incident surface on which the light emitted from the light source is incident, a second light incident surface on which the light emitted from the second point light source is incident, and orthogonal to the first and second light incident surfaces. A light exit surface for emitting light incident on the first and second light entrance surfaces as linear light, and an upper side of the plurality of light entrance surfaces And a plurality of grooves having an upper side of the light emitting surface and having a plurality of grooves which are regularly arranged and form an angle of 35 ° to 55 ° with the upper side of the light emitting surface on the first point light source side. A plurality of grooves which are regularly arranged to face the pattern surface and the first pattern surface and form an angle between 35 ° and 55 ° on the second point light source side with the bottom of the light emitting surface. And a second pattern surface having:

According to the fourteenth aspect, it is possible to provide a spread illuminating apparatus capable of increasing the brightness of the light emitted from the light emitting surface.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing the configuration of the arrangement of the rod-shaped light guide and the light source, and FIG. 2 is a top view showing the configuration of the arrangement of the rod-shaped light guide and the light source.

First, the rod-shaped light guide 10 has a quadrangular prism shape, and has the following six surfaces.

1. Light incident surface 11 2. Pattern surface 12 3. Light emitting surface 13 4. 4. Opposing surface 14 facing light incident surface 11 5. Surface 15 facing pattern surface 12 For example, the length of the rod-shaped light guide 10 is 60.1 mm, the width (the distance between the surface 13 and the surface 16) is 2.8 mm, and the height (the surface 12
The distance between the surface 15 and the surface 15) is 1 mm.

The distance between the pattern surface 12 and the surface 15 facing the pattern surface 12 (the height of the rod-shaped light guide 10) is smaller than the width of the pattern surface 12 (the width of the rod-shaped light guide 10).

In the vicinity of the light entrance surface 11, which is one end surface of the rod-shaped light guide 10, a point light source 5 such as an LED chip is provided.
0 is arranged.

Pattern surface 12 having pattern of groove 21
Is provided substantially orthogonal to the light emitting surface 13 in the longitudinal direction of the rod-shaped light guide 10. The pattern surface 12 is a surface in which one side of the light incident surface 11 and one side of the light exit surface 13 are connected (a surface having one side of the light incident surface 11 and one side of the light exit surface 13). A plurality of grooves 21 are regularly arranged on the pattern surface 12.

For example, the number of the grooves 21 is about 106, the pitch is 0.5 mm, the width is 0.05 mm, and the length is 3.96 m.
m, the depth is 0.05 mm.

A point light source 50 between the groove 21 and one side of the light emitting surface 13
A plurality of the grooves 21 are formed in the longitudinal direction so that the angles α formed on the sides have the same value.

A point light source 50 between the groove 21 and one side of the light emitting surface 13
The main component light from the point light source 50 parallel to the longitudinal direction of the rod-shaped light guide 10 is reflected by the light source side surface 22 of the groove 21 and is substantially perpendicular to the light exit surface 13. It is formed at an angle of about 45 ° so that the light exits from the light exit surface 13 in the direction.

Here, approximately 45 ° means 35 ° to 55 °.
°. Preferably, it is 40 ° to 50 °, more preferably 45 °. The angle in the substantially vertical and substantially orthogonal directions is 80 ° to 100 °. And
Preferably, the angle is between 85 ° and 95 °, more preferably 90 °.

According to this configuration, it is possible to improve the light use efficiency of the incident light. Further, the viewing angle characteristics of the light emitted from the light emitting surface depending on the location of the rod-shaped light guide can be made uniform.

The grooves 21 are arranged at a pitch such that adjacent grooves 21 are continuous at least in the longitudinal direction or partially overlap. That is, when viewed from the width direction of the rod-shaped light guide 10, the adjacent grooves 21 form an end of the upstream groove 21 on the light emitting surface 13 side and a surface 15 of the downstream groove 21.
The pitch is determined so that the side ends are continuous or partially overlap.

According to this configuration, it is possible to further improve the light use efficiency of the incident light. The adjacent grooves 21
When the number of overlapping portions increases, the number of light rays passing through the opposite surface of the incident surface 11 decreases, and the light use efficiency can be improved. However, when the number of overlapping portions between the adjacent grooves 21 is increased, the pitch becomes narrow, so that the workability is reduced.

FIGS. 3A to 3D are detailed enlarged views showing modified examples of the cross-sectional shape of the groove according to the present invention as seen from the AA direction shown in FIG. The variation of this groove is
The present invention is not limited to this embodiment, but can be applied to other embodiments.

In FIG. 3A, the cross-sectional shape of the groove 21A is rectangular, and the light source side 22 is the pattern surface 1 of the rod-shaped light guide 10.
2 is approximately 90 °.

In FIG. 3B, the sectional shape of the groove 21B is U-shaped. The light source side surface 22 has a plane approximately 90 ° with respect to the pattern surface 12 of the rod-shaped light guide 10 and a curved surface having a semicircular cross section.

In FIG. 3C, the cross-sectional shape of the groove 21 C is a right triangle, and the light source side surface 22 is substantially 90 ° with respect to the pattern surface 12 of the rod-shaped light guide 10.

In FIG. 3D, the cross-sectional shape of the groove 21D is an inverted trapezoid, and the light source side surface 22D has an obtuse angle larger than 90 ° with respect to the pattern surface 12 of the rod-shaped light guide 10. By making the cross-sectional shape of the groove 21D an inverted trapezoid, molding with a mold becomes easy.

As shown in FIGS. 3A to 3C, the angle θ between the light source side surface 22 of the grooves 21A to 21C and the pattern surface 12 having the pattern of the rod-shaped light guide 10 is approximately 90 °.
(80 ° to 100 °) is desirable, and more preferably 90 ° <θ ≦ 95 ° in consideration of molding by a mold. The obtuse angle θ in FIG. 3D is desirably 95 ° <θ ≦ 105 ° so that the reflected light from the light source side surface 22D is efficiently emitted from the light emitting surface 13 (not shown).

FIG. 4 is a schematic diagram showing the principle of operation according to the first embodiment of the present invention. Referring to FIG. 4, the first embodiment of the present invention will be further described.

The light beam 90 emitted from the point light source 50 passes through the light incident surface 11 of the rod-shaped light guide 10, is reflected by the light source side surface 22 inclined at approximately 45 ° with respect to the light exit surface 13, and is approximately 90 °.
The direction is changed, and the light exits from the light exit surface 13. Actually, only a small amount of light directly reaches the light source side surface 22 of the groove 21 from the point light source 50, and most of the light is reflected between the non-groove portions of the pattern surface 12 (see the surface 15 in FIG. 1). Is repeated, and reaches the light source side surface 22 of the groove 21.

However, since the distance between the pattern surface 12 on which the groove 21 of the rod-shaped light guide 10 is formed and the opposing surface is smaller than the width of the pattern surface 12, the light incident surface 11 is directly connected to the light incident surface 11. The number of light rays passing through the not-shown facing surface 14 is reduced, and the light use efficiency can be increased.

FIG. 15 is a schematic diagram showing the measurement results of the angular distribution of the light rays emitted from the rod-shaped light guide according to the present invention.
In FIG. 15, the angular distribution of the outgoing light beam from the rod-shaped light guide 10 is schematically shown at three points near the light incident surface 11, the center, and the vicinity of the facing surface 14. An angular distribution exists.

According to the present invention, the angular distribution of the light emitted from the rod-shaped light guide 10 is substantially constant regardless of the location, and the light exit surface 13
Are substantially symmetrical in the vertical direction. <Variations of First Embodiment> Variations of the means for controlling the light quantity distribution in the first embodiment of the present invention will be described below with reference to FIGS.

In the first embodiment, the pitch of the grooves 21 is set at equal intervals.

On the other hand, in the variation of FIG. 9, the pitch P of the groove 21 of the linear light guide 10 becomes gradually narrower as P1, P2, P3,... are doing.

For example, the pitch P1 of the groove 21 is 0.5 m
m, pitch P2 is 0.49 mm, pitch P3 is 0.48
mm, the pitch Pn is 0.14 mm, and the number n of the grooves is 150 (106 or more).

Next, in the variation of FIG. 10, as the width W of the groove 21 of the linear light guide 10 becomes farther from the point light source 50, the width W gradually becomes W1, W2, W3,. I'm making it big. The groove 21 is formed as the groove 21W1, the groove 21W2, and the groove 21 move away from the point light source 50.
.., The groove 21Wn gradually increases.

For example, the width W1 of the groove 21 is 0.0140 m
m, width W2 is 0.0142 mm, width W3 is 0.0144
mm, the width Wn is 0.0500 mm, and the number n of the grooves is about 106.

In this case, the cross-sectional shape of the groove 21 is preferably a V-shape.

Further, in the variation of FIG. 11, as the length N of the groove 21 of the linear light guide 10 moves away from the point light source 50, it gradually becomes N1, N2, N3,. It is long. The groove 21 is formed as the groove 21N1, the groove 21N2, and the groove 21 move away from the point light source 50.
N3,..., Grooves 21Nn gradually become longer.

For example, the length N1 of the groove 21 is 1.109 m
m, length N2 is 1.125 mm, length N3 is 1.140
mm, the length Nn is 3.960 mm, and the number n of the grooves is about 106.

Subsequently, in the variation of FIG. 12, as the depth F of the groove 21 of the linear light guide 10 becomes farther from the point light source 50, the depth F gradually becomes F1, F2, F3,. To be deep. The groove 21 is formed as the groove 21F1, the groove 21F2, and the groove 2 move away from the point light source 50.
1F3,..., The grooves 21Fn gradually become deeper.

For example, the depth F1 of the groove 21 is 0.0140
mm, depth F2 is 0.0142 mm, and depth F3 is 0.0
144 mm, depth Fn is 0.050 mm, number of grooves n is 1
It is about 06.

As means for controlling the light quantity distribution in this way, 1) changing the pitch of the groove 21; 2) changing the groove width, especially in the case of a V-shaped groove section; 3) changing the length of the groove;
4) Changing the depth of the groove can be considered, or these can be combined. <Second Embodiment> A second embodiment of the present invention will be described below with reference to FIGS.

FIG. 5 is a top view showing a configuration in which point light sources are respectively arranged on both end surfaces of the rod-shaped light guide, and grooves are formed on both sides of the rod-shaped light guide.

FIG. 6 is a perspective view of a single rod-shaped light guide having grooves formed on both surfaces according to the second embodiment of the present invention.

The rod-shaped light guide 10 has the following six surfaces.

1. 1. First end face portion 17 functioning as first light incident surface First pattern surface 12 3. Light emitting surface 13 4. 4. a second end surface portion 18 facing the first end surface portion 17 and functioning as a second light incident surface; 5. second pattern surface 19 facing first pattern surface 12 A surface 16 facing the light emitting surface 13 is provided near the first end face portion 17 of the rod-shaped light guide 10.
A point light source 50L is arranged, and a second point light source 50R is arranged near the other second end face portion 18 of the rod-shaped light guide 10.

The first pattern surface 12 is provided substantially orthogonal to the light emitting surface 13 in the longitudinal direction of the rod-shaped light guide 10. The first pattern surface 12 includes an upper side of the first end surface portion 17 and the light emitting surface 1.
3 (a surface in which the upper side of the first end face portion 17 and the upper side of the light emitting surface 13 are connected). First pattern surface 1
2, a plurality of first grooves 21L are regularly arranged. A plurality of first grooves 21L are formed such that an angle α between the upper side of the light emitting surface 13 and the first point light source 50L side is α ≒ 45 °. The first groove 21L has a first light source side surface 22L, and reflects a light beam from the first point light source 50L to the light emitting surface 13 side.

The second pattern opposing the first pattern surface 12
The pattern surface 19 is also provided with a plurality of second grooves 21R such that an angle α formed between the lower side of the light emitting surface 13 and the second point light source 50R is α ≒ 45 °. 2nd groove 21R
Has a second light source side surface 22R, and has a second point light source 5
Light rays from 0R are reflected to the light emitting surface 13 side.

As described above, a plurality of grooves 21 are formed on both surfaces of the first pattern surface 12 and the second pattern surface 19. The inclination direction of the groove 21 is such that the first pattern surface 12 and the second pattern surface 19 are arranged so that the light from the point light source 50 disposed on the left and right of the rod-shaped light guide 10 is emitted to the light emitting surface 13.
It is desirable to arrange them in the opposite direction.

According to this configuration, the emitted light emitted from the light emitting surface 13 can have higher brightness. <Third Embodiment> Hereinafter, a third embodiment of the present invention will be described with reference to FIG.

FIG. 7 is a structural view of the rod-shaped light guide of FIG. 5, which is the second embodiment, in which a V-shaped groove is added to the surface facing the light exit surface.

A plurality of V-shaped grooves 25 are formed on the surface of the rod-shaped light guide 10 facing the light exit surface 13 in the longitudinal direction of the rod-shaped light guide 10. An angle relationship between two sides having a right angle of a right-angled isosceles triangle is desirable as a V-shape. The V-shaped groove 25 has a first light source side slope 25L and a second light source side slope 2L.
5R. The first light source side slope 25L reflects the light rays from the first point light source 50L to the light emitting surface 13 side,
The light source side inclined surface 25R reflects light rays from the second point light source 50R to the light emitting surface 13 side.

According to this configuration, it is possible to completely improve the light use efficiency of the incident light. <Fourth Embodiment> Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.

FIG. 8 is a configuration diagram in which grooves are formed on both surfaces of the rod-shaped light guide according to the first embodiment.

On the upper pattern surface 12 of the rod-shaped light guide 10,
A plurality of third grooves 21U are formed so that an angle formed between the upper side of the light emitting surface 13 and the point light source 50 side is α ≒ 45 °. The third groove 21U has a light source side third side surface 22U, and reflects a light beam from the point light source 50 to the light emitting surface 13 side.

Further, the fourth groove 2 is also formed on the lower pattern surface 19 facing the upper pattern surface 12 such that the angle α between the lower side of the light emitting surface 13 and the point light source 50 side is α ≒ 45 °.
A plurality of 1Ss are formed. The fourth groove 21S has a light source side fourth side surface 22S, and reflects a light beam from the point light source 50 to the light emitting surface 13 side.

The inclination directions of the third groove 21U and the fourth groove 21S are desirably arranged in the same direction because light rays from the same point light source 50 are emitted to the light emitting surface 13.

As described above, the point light source 50 is connected to the rod-shaped light guide 10.
Even if it is arranged only on one end surface portion 11, the grooves 21 are formed on both the upper pattern surface 12 that is substantially perpendicular to the light emitting surface 13 in the longitudinal direction of the rod-shaped light guide 10 and the other lower pattern surface 19. Is formed, it is possible to further increase the light use efficiency with respect to the first embodiment. <Surface Illumination Device in Second Embodiment> A surface illumination device using a linear illumination device according to a second embodiment of the present invention will be described below with reference to FIGS. In the planar lighting device shown in FIGS. 13 and 14, the linear lighting device according to the second embodiment is used, but the present invention can be applied to other embodiments.

FIG. 13 is a block diagram of a planar lighting device using a rod-shaped light guide having grooves on both sides according to the second embodiment as a linear light source of a backlight or a front light.

FIG. 14 is a configuration diagram showing a center line cross-sectional view of the planar illumination device of FIG.

The linear illuminating device 100, which is a light source unit as a linear light source, includes a first point light source 50L, a second point light source 50R (not shown), a rod-shaped light guide 10, and a reflector 70 having a reflecting function. It is composed of

A planar lighting device 150 as a planar light source is
It comprises a linear lighting device 100 and a planar light guide plate 80 for converting a linear light source into a planar light source.

The planar light guide plate 80 is arranged so as to face the light exit surface 13 of the rod-shaped light guide 10 constituting the linear illumination device 100, and is held by the reflector 70 of the linear illumination device 100. The planar light guide plate 80 includes an incident surface 81 on which light emitted from the light exit surface 13 of the linear illumination device 100 is incident,
A reflecting surface 82 that is orthogonal to the incident surface 81 and reflects light incident on the incident surface 81, and an emitting surface 83 that faces the reflecting surface 82 and emits light reflected from the reflecting surface 82 as planar light. Have.

In FIG. 13, the first light source side surface 22 is shown.
Although L can be confirmed, the second light source side surface 22R cannot be visually recognized since FIG. 13 is viewed from the first point light source 50L side.

In the present invention, since a diffusion sheet and a lens sheet are not required, the cost and the number of assembling steps can be reduced, and the productivity of the linear lighting device can be improved.

In these embodiments, some of the drawings are schematically illustrated for easy understanding, and there are portions different from actual dimensions and actual scale ratios.

[0085]

As is clear from the above description, in the rod-shaped light guide according to the first aspect of the present invention, one side of the light entrance surface and one side of the light exit surface are connected to each other. A plurality of grooves are regularly arranged on the pattern surface on which the groove is formed, and an angle between the groove and one side of the light exit surface on the point light source side is formed at 35 ° to 55 °. So
The main component light from the point light source is reflected by the groove, and the light is emitted from the light emitting surface in a direction substantially perpendicular to the light emitting surface. As a result, the light use efficiency of the incident light can be improved. Further, the viewing angle characteristics of the light emitted from the light emitting surface depending on the location of the linear light guide can be made uniform.

In the rod-shaped light guide of the present invention according to claim 7,
An angle between the upper side of the light emitting surface and the first point light source is 3
A first pattern surface having a plurality of grooves formed at 5 ° to 55 °, and regularly arranged opposite to the first pattern surface, on a second point light source side with respect to a bottom of the light emitting surface; Since the second pattern surface having a plurality of grooves formed at an angle of 35 ° to 55 ° is provided, the emitted light emitted from the light emitting surface can have higher brightness.

In the linear illuminating device according to the eleventh aspect of the present invention, the main component light from the point light source is reflected by the groove, and the light is emitted from the light emitting surface in a direction substantially perpendicular to the light emitting surface. Can be improved in light use efficiency. Further, the viewing angle characteristics of the light emitted from the light emitting surface depending on the location of the linear light guide can be made uniform. Further, since a diffusion sheet and a lens sheet are not required, the cost and the number of assembling steps can be reduced, and the productivity of the linear lighting device can be improved.

According to the twelfth aspect of the present invention, it is possible to provide a linear illuminator capable of increasing the intensity of light emitted from the light exit surface.

In the spread illuminating apparatus according to the thirteenth aspect of the present invention, the main component light from the point light source is reflected by the groove, and the light is emitted from the light emitting surface in a direction substantially perpendicular to the light emitting surface. Can be improved in light use efficiency. Further, the viewing angle characteristics of the light emitted from the light emitting surface depending on the location of the linear light guide can be made uniform. Further, since a diffusion sheet and a lens sheet are not required, the cost and the number of assembling steps can be reduced, and the productivity of the spread illuminating device can be improved.

According to the fourteenth aspect of the present invention, it is possible to provide a spread illuminating apparatus capable of increasing the intensity of light emitted from the light emitting surface.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an arrangement of a rod-shaped light guide and a light source according to a first embodiment of the present invention.

FIG. 2 is a top view showing a configuration of an arrangement of a rod-shaped light guide and a light source according to the first embodiment of the present invention.

FIGS. 3A to 3D show the groove according to the invention in FIG.
It is an enlarged explanatory view showing an example of a sectional shape seen from the middle AA direction.

FIG. 4 is a schematic diagram illustrating an operation principle according to the first embodiment of the present invention.

FIG. 5 is a top view showing a configuration in which point light sources are respectively disposed on both end surfaces of a rod-shaped light guide according to a second embodiment of the present invention, and grooves are formed on both surfaces of the rod-shaped light guide. .

FIG. 6 is a perspective view of a rod-shaped light guide alone according to a second embodiment of the present invention.

FIG. 7 is a configuration view of a third embodiment of the present invention, in which a V-shaped groove is added to a surface facing a light exit surface of the rod-shaped light guide of FIG. 5 which is a second embodiment. .

FIG. 8 is a configuration diagram in which a point light source is disposed on one end surface of a rod-shaped light guide according to a fourth embodiment of the present invention, and grooves are formed on both surfaces of the rod-shaped light guide.

FIG. 9 is a configuration diagram in which the pitch of the grooves of the linear light guide according to the present invention is gradually narrowed as the distance from the point light source increases.

FIG. 10 is a configuration diagram in which the width of the groove of the linear light guide according to the present invention gradually increases as the distance from the point light source increases.

FIG. 11 is a configuration diagram in which the length of the groove of the linear light guide according to the present invention gradually increases as the distance from the point light source increases.

FIG. 12 is a configuration diagram in which the depth of the groove of the linear light guide according to the present invention is gradually increased as the distance from the point light source increases.

FIG. 13 is a configuration diagram of a planar illumination device using a rod-shaped light guide having grooves formed on both sides as a light source of a backlight or a front light according to a second embodiment of the present invention.

14 is a configuration diagram showing a center line cross-sectional view of the planar lighting device of FIG. 13 according to the present invention.

FIG. 15 is a schematic diagram showing an angular distribution of light rays emitted from a rod-shaped light guide according to the present invention.

FIG. 16 is a schematic view showing a configuration of a conventional rod-shaped light guide.

FIG. 17 is a schematic diagram showing a configuration of a cross section of a center line in a conventional planar illumination device.

FIG. 18 is a schematic diagram showing an angular distribution of light rays emitted from a conventional rod-shaped light guide.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 rod-shaped light guide 11 light-entering surface 12 pattern surface 13 light-emitting surface 14 facing surface 17, 18 end surface portion 21 groove 22 light source side surface of groove 25 V-shaped groove 50 point light source 70 reflector 80 planar light guide plate 81 planar Incident surface of light guide plate 82 Reflective surface of planar light guide plate 83 Exit surface of planar light guide plate 90 Light ray 100 Linear illumination device 150 Surface illumination device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toru Nose 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Nobuo Iwazuki 2-chome Keihanhondori, Moriguchi-shi, Osaka No.5-5 Sanyo Electric Co., Ltd. F-term (reference) 2H038 AA52 AA55 BA01 BA06

Claims (14)

[Claims] A light incident surface on which light emitted from a point light source is incident; a light emitting surface orthogonal to the light incident surface and emitting light incident on the light incident surface as linear light; A surface where one side of the writing light surface and one side of the light emitting surface are connected, a pattern surface in which a plurality of grooves are formed, a surface facing the light emitting surface, and a surface facing the pattern surface. Wherein the plurality of grooves are regularly arranged on the pattern surface, and an angle formed between the groove and one side of the light exit surface on the point light source side is formed at 35 ° to 55 °. A rod-shaped light guide, characterized in that: 2. The rod-shaped conductor according to claim 1, wherein the plurality of grooves formed on the pattern surface are arranged at a pitch at which adjacent grooves partially overlap at least in a longitudinal direction. Light body. 3. The rod-shaped light guide according to claim 1, further comprising a plurality of grooves regularly arranged on a surface facing the light emitting surface. 4. The rod-shaped light guide according to claim 1, wherein a distance between the pattern surface and a surface facing the pattern surface is smaller than a width of the pattern surface. 5. A plurality of grooves which are regularly arranged on a surface facing the pattern surface and have an angle of 35 ° to 55 ° with the lower side of the light emitting surface on the side of the point light source are further formed. The rod-shaped light guide according to claim 1, wherein: 6. The rod-shaped light guide according to claim 5, wherein the plurality of grooves are arranged at a pitch at which adjacent grooves partially overlap at least in a longitudinal direction. 7. A first light incident surface on which light emitted from a first point light source is incident, and light emitted from a second point light source is opposed to the first light incident surface. A second light entrance surface, a light exit surface orthogonal to the plurality of light entrance surfaces, and emitting light incident on the plurality of light entrance surfaces as linear light, a surface facing the light exit surface, It has an upper side of a plurality of light entrance surfaces and an upper side of the light exit surface, is regularly arranged, and forms an angle of 35 ° to 55 ° with the upper side of the light exit surface on the first point light source side. A first pattern surface having a plurality of grooves, and an angle formed on the second point light source side with respect to the first pattern surface, which is regularly arranged and forms a bottom with the light emitting surface, is 35 °.
A second pattern surface having a plurality of grooves formed at an angle of from 55 ° to 55 °. 8. The plurality of grooves formed on the first and second pattern surfaces are arranged at a pitch such that adjacent grooves partially overlap at least in the longitudinal direction. 8. The rod-shaped light guide according to 7. 9. The rod-shaped light guide according to claim 7, further comprising a plurality of grooves regularly arranged on a surface facing the light emitting surface. 10. The rod-shaped light guide according to claim 7, wherein a distance between the first pattern surface and the second pattern surface is smaller than a width of each of the first and second pattern surfaces. 11. A point light source; a light incident surface on which light emitted from the point light source is incident;
In a linear lighting device including a light exit surface that is orthogonal to the light entrance surface and emits light incident on the light entrance surface as linear light, and a rod-shaped light guide, the rod-shaped light guide includes: One side of the light entrance surface and one side of the light exit surface are connected surfaces, and this surface has a pattern surface on which a plurality of grooves are formed, and the plurality of grooves are regularly formed on the pattern surface. A linear lighting device, wherein an angle between the groove and one side of the light emitting surface on the side of a point light source is formed in a range of 35 ° to 55 °. 12. A first point light source, a second point light source, and a first point light to which light emitted from the first point light source is incident.
A light incident surface, a second light incident surface on which light emitted from the second point light source is incident, and orthogonal to the first and second light incident surfaces, and on the first and second light incident surfaces. In a linear lighting device including: a light-emitting surface that emits incident light as linear light; and a rod-shaped light guide, the rod-shaped light guide includes an upper side of the plurality of light-entering surfaces and a light-emitting surface of the light-emitting surface. The first point light source has an upper side and is regularly arranged, and has an angle of 3 with the upper side of the light emitting surface.
A first pattern surface having a plurality of grooves formed at 5 ° to 55 °, and regularly arranged opposite to the first pattern surface, on a second point light source side with respect to a bottom of the light emitting surface; And a second pattern surface having a plurality of grooves formed at an angle of 35 ° to 55 °. 13. A planar illuminator in which a linear illuminator comprising a point light source and a rod-shaped light guide is arranged close to a side surface of a planar light guide plate made of a translucent material. An incident surface on which light emitted from the light exit surface of the cylindrical illumination device is incident;
A rod-shaped reflecting surface that intersects at 00 ° and reflects light incident on the incident surface, and an emitting surface that faces the reflecting surface and emits light reflected from the reflecting surface as planar light; The light guide is a light incident surface on which light emitted from the point light source is incident, and a light exit surface that is orthogonal to the light incident surface and emits light incident on the light incident surface as linear light, One side of the light entrance surface and one side of the light exit surface are connected to each other, and have a pattern surface in which a plurality of grooves are formed. In the pattern surface, the plurality of grooves are regularly formed. Are arranged
A planar illumination device, wherein an angle formed between the groove and one side of the light exit surface on a point light source side is formed in a range of 35 ° to 55 °. 14. A spread illuminating apparatus in which a linear illuminating apparatus comprising first and second point light sources and a rod-shaped light guide is disposed close to a side surface of a planar light guiding plate made of a translucent material. The light guide plate has an incident surface on which light emitted from the light exit surface of the linear illumination device is incident, and an incident surface between 80 ° and 1 °.
A rod-shaped reflecting surface that intersects at 00 ° and reflects light incident on the incident surface, and an emitting surface that faces the reflecting surface and emits light reflected from the reflecting surface as planar light; A light guide, a first light incident surface on which light emitted from the first point light source is incident, and a second light incident surface on which light emitted from the second point light source is incident; The first and second
A light exit surface that is orthogonal to the light entrance surface and emits light incident on the first and second light entrance surfaces as linear light, and has an upper side of the plurality of light entrance surfaces and an upper side of the light exit surface A first pattern surface having a plurality of grooves which are regularly arranged and have a plurality of grooves formed at an angle of 35 ° to 55 ° with the upper side of the light emitting surface on the first point light source side; A light-exiting surface that is regularly arranged and has a second
And a second pattern surface having a plurality of grooves formed at an angle of 35 ° to 55 ° on the point light source side.