JP3696095B2 - Illumination device and display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination device including a point light source, a linear light guide, and a light guide plate, and a display device including the illumination device and a non-light emitting display means.
[0002]
[Prior art]
In recent years, technologies for reducing the weight, size, and power consumption of electronic devices have been remarkably developed. In the flow of this technology, the use of non-luminous display means has reduced the weight of electronic devices and reduced the size. It is worth noting that the power consumption has been reduced.
[0003]
The liquid crystal display device includes a transmission type and a reflection type. The transmission type liquid crystal display device is provided with an illuminating device that illuminates the non-light emitting display means from the back side, a so-called backlight. Is provided with a so-called front light that illuminates the non-luminous display means from the front side.
[0004]
These illuminating devices include a linear light source and a light guide plate that allows light from the linear light source to be incident from one end surface, and to be distributed in a planar manner from either one of the front and back surfaces (Japanese Patent Laid-Open No. Hei 10-). No. 153777, Japanese Patent Laid-Open No. 10-311915, etc.).
[0005]
For example, as schematically shown in the cross-sectional view of FIG. 9, a lighting device 102 is disposed as a front light on the surface side of the reflective non-light-emitting display means 101. The light plate 104 is provided with an antireflection film 106 provided on the back surface of the light guide plate 104 so as to face the non-light emitting display means 101 in order to improve visibility.
[0006]
Some of the linear light sources 103 use linear arc tubes, light emitting diode arrays, etc., but in order to reduce power consumption, for example, as shown in FIG. 10, a point light source 131 such as a light emitting diode, A light source having a linear or rod-shaped light guide 132 that is incident on one end of the point light source 131 and is dispersed and emitted linearly is widely used. Further, as shown in FIG. 9, the linear light source 103 is provided with a reflection plate 107 for directing the emitted light to one end surface of the light guide plate 104 as necessary.
[0007]
On the surface 147 of the light guide plate 104, a reflection surface 145 that disperses the light incident on one end surface of the light guide plate 104 from the linear light source 103, that is, the incident surface 141, and reflects it to the back surface 142 side, and the non-light emitting display means 101. The light-transmitting surfaces 146 that allow light incident on the back surface of the light guide plate 104 to be transmitted to the front surface side of the light guide plate 104 are alternately formed.
[0008]
The reflection surface 145 is inclined, for example, by 45 ° with respect to the horizontal plane so as to be directed to the incident surface 141 on which the light from the linear light source 103 is incident, and the translucent surface 146 is directed to the end surface 143 opposite to the incident surface 141. For example, it is inclined 2 ° with respect to the horizontal plane. The depth of the valley sandwiched between the reflecting surface 145 and the light transmitting surface 146 or the height of the mountain sandwiched between the light transmitting surface 146 and the reflecting surface 145 is uniformly formed over the entire surface of the light guide plate 104. The
[0009]
[Problems to be solved by the invention]
By the way, in this display device, if the positional relationship between the linear light guide and the light guide plate is shifted, light is not sufficiently incident on a part of the light guide plate, and sufficient light is not incident on the non-light emitting display means 101. A dark part that is not irradiated is generated, a part of the light emitted from the light guide 104 leaks without entering the light guide plate 104, or the diffuse light directly enters the light guide plate 104 from the point light source 131 and the bright line K is generated. May appear.
[0010]
Therefore, when the linear light guide and the light guide plate are integrally formed, an attempt was made to prevent positional deviation between the linear light guide and the light guide plate. The light incident on the light guide plate diffuses directly into the light guide plate and does not reach the opposite end of the linear light guide sufficiently, resulting in a dark part of the light guide plate or light concentration. It was found that bright lines and bright parts were generated, making it impractical.
[0011]
Further, as a light guide that converts a point light source such as an LED light source into a linear light source, a point light source 131 is disposed on a light incident surface 134 that is an end surface of a linear light guide 132 as shown in FIG. A system is known in which a plurality of V-shaped grooves, for example, are formed in the longitudinal direction of the linear light guide 132 on the reflective surface 133 facing the light exit surface 139 on one side in the longitudinal direction. In this method, the light beam G, which is a part of the light beam that enters the linear light guide 132 from the point light source 131, is directly on the slope of the V-shaped groove provided on the reflecting surface 133 of the linear light guide 132. The light reaches the light exit surface 139 at an angle equal to or smaller than the critical angle of the light exit surface 139 by being reflected by the inclined surface, and exits from the light exit surface 139. Further, the other part of the incident light beam is repeatedly reflected until the angle between the light exit surface 139 and the reflection surface 133 becomes an angle less than the critical angle. In such a principle, by setting the pitch or depth distribution of the V-shaped groove to an appropriate value, the light amount distribution of the outgoing light from the light exit surface 139 can be made substantially uniform, resulting in a linear shape. A light source can be obtained.
[0012]
However, in the configuration as shown in FIG. 11 described above, the linear light guide 132 is formed in a rectangular cross section having a uniform thickness, so that the reflecting surface 133 is parallel to the optical axis of the incident light from the point light source 131. Thus, most of the light incident from the light incident surface 134 is not irradiated on the reflecting surface 133. In other words, the light H that is perpendicular to the light incident surface 134 and is not blocked by the V-shaped groove does not reach the reflecting surface 133 and has a disadvantage that the light use efficiency of incident light is reduced.
[0013]
More specifically, as shown in FIG. 12, when the side surface width Q is longer than the height P of the linear light guide 132, the area occupied by the V-shaped groove is smaller than the cross-sectional area. For this reason, the ratio of the light that repeatedly reflects between the light exit surface 139, the reflective surface 133, and the side surface reaches the light source 131 side slope (see FIG. 11) of the V-shaped groove provided on the reflective surface 133 is low, and the reflection The number of rays that do not reach the surface 133 and pass through the opposite surface of the light incident surface 134 increases, and the light use efficiency of incident light decreases.
[0014]
Further, the incident angle of the V-shaped groove on the light source side 131 slope near the light incident surface 134 that reaches directly from the point light source 131 where the light intensity is the highest, and the V angle at a location far from the light incident surface 134. Since the incident angle of the letter-shaped groove to the slope on the light source 131 side is different, as shown in FIG. 13, the viewing angle characteristics of the emitted light from the light exit surface 139 vary depending on the location. In FIG. 13, the angular distribution of the light beam emitted from the linear light guide 132 is schematically shown at three points near the light incident surface 134, near the center, and near the end surface opposite to the light incident surface. However, the angular distribution of the emitted light also exists in other parts.
[0015]
In order to use such a linear light source 103 as a light source of the light guide plate 104, for example, as shown in FIG. 12, a diffusion sheet 121 and a lens sheet 122 must be disposed on the light exit surface 139 side for correction. As a result, productivity has deteriorated due to cost increases and assembly man-hours.
[0016]
  The first object of the present invention is toEnterAn object of the present invention is to provide an apparatus capable of improving the light use efficiency of incident light and making the light emitted from the light output surface of the linear light guide uniform over the entire longitudinal direction. In particular, when the pattern surface of the linear light guide and the first main surface of the light guide plate are arranged on the same side, there is no need to complicate the mold structure, reducing costs and reducing assembly man-hours. It is providing the apparatus which can aim at the improvement of property.
[0017]
  The second object of the present invention is to further improve the light utilization efficiency of the incident light, and make the light emitted from the light output surface of the linear light guide uniform over the entire longitudinal direction.At the same time, the brightness of the emitted light emitted from the light emitting surface is increased.That is.
[0018]
  The third object of the present invention is toIt is an object of the present invention to provide an apparatus that eliminates a shift in the positional relationship between a linear light guide and a light guide plate. In addition, the light incident from one end of the linear light guide is reflected by the light exit surface of the linear light guide and is averagely dispersed to reach the other end side, and is averagely dispersed from the linear light guide. It is an object of the present invention to provide a device capable of preventing the occurrence of dark parts, bright lines, bright parts, etc. by making the incident light incident on one end surface of the light guide plate.
[0019]
A fourth object of the present invention is to improve the uniformity of image quality by uniformly dispersing light emitted from the light guide plate in a planar manner.
[0026]
[Means for Solving the Problems]
  Claim1The present invention relates to a point light source, a light incident surface on which light emitted from the point light source is incident, and light that is orthogonal to the light incident surface and incident on the light incident surface is emitted as linear light. A linear light guide having a light exit surface, a pattern surface having one side of the light entrance surface and one side of the light exit surface, and formed with a plurality of grooves, and light emitted from the linear light guide A light guide plate that is incident from an incident surface consisting of one end surface, reflects light incident on the incident surface at the first main surface where a plurality of grooves are formed, and disperses and emits the light in a plane from the second main surface. A plurality of grooves regularly arranged on a pattern surface of the linear light guide, and an angle formed between the grooves and one side of the light exit surface on the point light source side is approximately The pattern surface of the linear light guide and the first main surface of the light guide plate are on the same surface side or the opposite surface side. A lighting device characterized in that it is location.
[0027]
  Claim1With this configuration, a plurality of grooves are regularly arranged on the pattern surface of the linear light guide, and an angle formed on the point light source side between the grooves and one side of the light output surface is formed to be approximately 45 °. Since the pattern surface where the plurality of grooves of the linear light guide are formed and the first main surface where the plurality of grooves of the light guide plate are formed are arranged on the same surface side or the opposite surface side, the incident light Light utilization efficiencyImprovementThe light emitted from the light exit surface of the linear light guide can be made uniform over the entire length direction.
  In particular, when the pattern surface of the linear light guide and the first main surface of the light guide plate are arranged on the same side, there is no need to complicate the mold structure, so the cost is reduced and the assembly man-hour is reduced. Productivity can be improved.
[0028]
  Claim2The present invention relates to first and second point light sources, a first light incident surface on which light emitted from the first point light source is incident, and opposed to the first light incident surface, A second light incident surface on which light emitted from the two point light sources is incident; and a light output surface that is orthogonal to the plurality of light incident surfaces and emits light incident on the plurality of light incident surfaces as linear light; And a plurality of grooves having an upper side of the light incident surface and an upper side of the light output surface, and an angle formed on the first point light source side with respect to the upper side of the light output surface is approximately 45 °. A first pattern surface and a second pattern surface having a plurality of grooves facing the first pattern surface and having an angle formed by the bottom of the light exit surface on the second point light source side at approximately 45 °. A linear light guide provided, and light emitted from the linear light guide is incident from an incident surface composed of one end surface to form a plurality of grooves And a light guide plate that reflects the light incident on the incident surface by the first main surface, and disperses the light from the second main surface in a plane and emits the light. The illumination device characterized in that the pattern surface and the first main surface of the light guide plate are disposed on the same surface side or the opposite surface side.
[0029]
  Claim2According to the configuration, the linear light guide having the plurality of point light sources and the plurality of pattern surfaces and the light guide are provided, and the first pattern surface of the linear light guide and the first main surface of the light guide plate are the same. Since it is arranged on the surface side or the opposite surface side, the light utilization efficiency of incident lightFurtherImprovement can be achieved, and the emitted light from the light exit surface of the linear light guide can be made uniform over the entire longitudinal direction, and the emitted light emitted from the light exit surface can be made high in luminance.
[0030]
  According to a third aspect of the present invention, the linear light guide is formed integrally with the light guide plate so as to face the incident surface of the light guide plate through an air layer over substantially the entire length thereof. The illumination device according to claim 1 or claim 2, wherein
According to the configuration of the third aspect, since the linear light guide is integrally formed with the light guide plate, the positional relationship between the linear light guide and the light guide plate is not shifted.
Further, since an air layer is interposed between the linear light guide and the light guide plate over substantially the entire length of the linear light guide, light incident from one end of the linear light guide is linearly guided. As a result of being reflected on the light exit surface of the body and being averagely dispersed and reaching the other end side, the light dispersed on the average from the linear light guide can be incident on one end surface of the light guide plate. Generation of bright lines and bright parts can be prevented.
As a method of integrally forming the linear light guide and the light guide plate, for example, a known method such as integral molding or integral injection molding may be employed, and the air layer uses a core, die cutting, lost wax, or the like. What is necessary is just to form.
  The present invention according to claim 4 is the illuminating device according to any one of claims 1 to 3, wherein an incident surface of the light guide plate is formed into a rough surface.
[0031]
According to the configuration of claim 4, when the incident surface of the light guide plate is formed to be rough, the light incident on the incident surface is provided with scattering properties, and the light having the average viewing angle characteristic is contained in the light guide plate. Therefore, the light emitted from the light guide plate is more evenly distributed in a plane, and the uniformity of image quality can be improved.
[0032]
The present invention according to claim 5 includes the illumination device according to any one of claims 1 to 4 and non-light-emitting display means arranged on the second main surface side of the light guide plate. Display device.
[0033]
According to the structure of Claim 5, the display apparatus which has the said effect can be provided.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
<First Embodiment>
A lighting device and a display device according to a first embodiment of the present invention will be specifically described with reference to FIGS.
[0035]
FIG. 1 is a front view schematically showing the illumination device according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the display device according to the embodiment. FIG. 3 is a cross-sectional view schematically showing the shape of the reflection groove of the linear light guide.
[0036]
As shown in FIG. 2, the display device according to the first embodiment of the present invention includes a non-light emitting display means 1 composed of a known reflective liquid crystal display means, and a display screen side of the non-light emitting display means 1. That is, the lighting apparatus 2 according to the first embodiment of the present invention is provided on the surface side.
[0037]
As shown in FIG. 1, the illuminating device 2 emits light over the entire length of a light guide plate 4 that covers the entire surface of the non-light-emitting display means 1 and an incident surface 41 formed by one end surface of the light guide plate 4. An incident linear light source 3 is provided. The linear light source 3 includes a linear light guide 32 formed integrally with the light guide plate 4 so as to face the incident surface 41 of the light guide plate 4 through the air layer 5 over substantially the entire length thereof, and the line. One point light source 31 (for example, LED) that makes a light beam incident on one end of the light guide 32 is provided.
[0038]
The linear light guide 32 and the light guide plate 4 are resin molded products in which a light-transmitting thermoplastic resin such as acrylic resin or polycarbonate resin is integrally formed by injection molding, and the air layer 5 is formed by die cutting. The
[0039]
A point light source 31 is provided on a light incident surface 34 that is one end of the linear light guide 32.
[0040]
Upper reflection grooves 38U are formed on the upper pattern surface 37U, which is the upper side surface of the linear light guide 32, at predetermined intervals. For example, the upper reflection grooves 38U are arranged at equal intervals in the longitudinal direction of the linear light guide 32, and the depths of the upper reflection grooves 38U are the same, or the depths of the upper reflection grooves 38U are constant. If the amount of light reflected from each upper reflection groove 38U is made the same by changing the pitch, the light uniformly dispersed over the entire length of the linear light guide 32 is transmitted from the linear light guide 32 to the light guide plate 4. Can be made incident.
[0041]
A plurality of upper reflection grooves 38U are formed in the longitudinal direction. Here, as shown in FIG. 1, the upper reflection groove 38 </ b> U is formed such that an angle formed by the upper reflection groove 38 </ b> U and one side of the light exit surface 39 on the point light source 31 side is α. The angle α is substantially normal to the light output surface 39 by reflecting the main component light from the point light source 31 parallel to the longitudinal direction of the linear light guide 32 on the light source side surface of the upper reflection groove 38U. It is formed at approximately 45 ° so as to exit from the light exit surface 39.
[0042]
According to this configuration, it is possible to improve the light use efficiency of incident light. Moreover, the emitted light from the light-emitting surface of the linear light guide can be made uniform over the entire longitudinal direction.
[0043]
The cross-sectional shape of the upper reflection groove 38U is not particularly limited, and for example, as shown in FIG. Can be adopted.
[0044]
As shown in FIGS. 3A, 3C, and 3D, the angle formed between the light source side surface of the upper reflection grooves 38UA, 38UC, and 38UD and the upper pattern surface 37U of the linear light guide 32 is desirably about 90 °, and more desirably. In consideration of the draft when the linear light guide 32 is formed by injection molding, the obtuse angle θ in FIG. 3B is desirably 90 ° <θ ≦ 95 °.
[0045]
Of the light that hits the upper reflection groove 38 </ b> U and travels toward the light guide plate 4, the light that reaches the light exit surface 39 at an angle smaller than the critical angle is transmitted with refraction and enters the air layer 5, and further enters the incident surface 41 of the light guide plate 4. Is incident on.
[0046]
Here, as described above, since the linear light guide 32 and the light guide plate 4 are integrated by integral injection molding, the assembly work of the lighting device 2 is simplified, and the linear light guide 32 and the light guide 32 are guided. There is no possibility that the positional relationship with the light plate 4 is distorted, and light that is linearly dispersed on the light guide plate 4 from the substantially entire length of the linear light guide 32 can be incident. Accordingly, there is no possibility that a dark portion where the light amount is insufficient or a bright line or a bright portion where the light amount is excessive is generated in the light guide plate 4.
[0047]
Next, as shown in FIG. 2, the second main surface (back surface) 42, which is the exit surface of the light guide plate 4, is formed flat, and as the light guide plate 4 approaches the opposite end surface 43 from the incident surface 41, A wedge shape is formed so as to approach the first main surface (surface) 47. Further, the first main surface 47 of the light guide plate 4 has a reflecting surface 45 inclined by, for example, 45 ° with respect to the horizontal plane so as to go to the incident surface 41 and a horizontal plane so as to go to the opposite end face. For example, translucent surfaces 46 in which γ is inclined by 2 ° are alternately formed. The reflective surface 45 and the translucent surface 46 form a groove 44 in the first main surface 47 of the light guide plate 4.
[0048]
Here, the reflecting surfaces 45 and the light-transmitting surfaces 46 are arranged in parallel to each other, and the lengths of the reflecting surfaces 45 in the flow direction are made equal, so that the reflecting surfaces 45 are equally spaced in a plan view, and They are arranged in parallel.
[0049]
In addition, as shown in FIG. 1, in plan view, the top line (mountain fold line) and the valley line (valley fold line) at which each reflecting surface 45 and the translucent surface 46 intersect are inclined with respect to the incident surface 41. Therefore, moire is not generated in the display image.
[0050]
Further, as shown in FIG. 2, the second main surface 42 of the light guide plate 4 is formed in a mirror surface like the conventional light guide plate, and a known antireflection film 6 is laminated to improve the visibility.
[0051]
Accordingly, a part of the light incident from the incident surface 41 is reflected by the reflecting surface 45 and emitted to the non-light emitting display means 1 side, and the light reflected by the non-light emitting display means 1 is transmitted from the second main surface 42. The light passes through the surface 46 and is emitted in a planar shape toward the front surface side of the light guide plate 4.
[0052]
By the way, in this 1st Embodiment, although the point light source 31 is provided in the end of the linear light guide 32, the pair of point light sources 31 which consist of LED, for example are opposed to the both ends of the linear light guide 32. You may arrange as follows.
[0053]
Further, in this embodiment, the reflection plate 7 is provided in order to make the light of the linear light source 3 incident on the light guide plate 4 without waste, but the reflection plate 7 may be omitted.
[0054]
In the present invention, a linear light source 32 formed integrally with the light guide plate 4 so that the linear light source 3 faces the incident surface of the light guide plate 4 through the air layer 5 over substantially the entire length thereof, The linear light guide 32 is provided with a point light source 32 that makes light incident on one end or both ends thereof. A plurality of grooves 38 </ b> U and 44 are formed in the upper pattern surface 37 </ b> U of the linear light guide 32 and the first main surface 47 of the light guide plate 4. Furthermore, the upper pattern surface 37U of the linear light guide 32 and the first main surface 47 of the light guide plate 4 are disposed on the same side. More preferably, they are arranged on substantially the same plane.
[0055]
In the present invention, the point light source 31, the linear light guide 32, and the light guide plate 4 are provided. The linear light guide 32 is a light incident surface 34 on which the light emitted from the point light source 31 is incident, and an outgoing light that is orthogonal to the light incident surface 34 and emits the light incident on the light incident surface 34 as linear light. The surface 39 includes an upper pattern surface 37U having one side of the light incident surface 34 and one side of the light output surface 39 and having a plurality of grooves 38U formed therein. In the light guide plate 4, the light emitted from the linear light guide 32 is incident from an incident surface 41 having one end surface, and the light incident on the incident surface is reflected by a first main surface 47 in which a plurality of grooves 44 are formed. The light is emitted by being dispersed in a planar manner from the second main surface 42. A plurality of grooves 38U are regularly arranged on the upper pattern surface 37U of the linear light guide 32, and the angle formed by the grooves 38U and one side of the light exit surface 39 on the point light source 31 side is approximately 45 °. The upper pattern surface 37U of the linear light guide 32 and the first main surface 47 of the light guide plate 4 are formed on the same side.
[0056]
<Second Embodiment>
Next, an illumination device according to a second embodiment of the present invention will be described with reference to FIG.
[0057]
FIG. 4 is a plan view schematically showing an illumination apparatus according to the second embodiment of the present invention. Lower reflective grooves 38S are formed at predetermined intervals on the lower pattern surface 37S, which is the lower surface of the linear light guide 32. An angle α formed between the lower reflection groove 38S and one side of the light exit surface 39 on the point light source 31 side is formed to be approximately 45 °. The lower pattern surface 37S of the linear light guide 32 and the first main surface 47 of the light guide plate 4 are formed on the opposite sides.
[0058]
Since other configurations are the same as those of the first embodiment, description thereof is omitted.
[0059]
<Third Embodiment>
Next, an illumination device and a display device according to a third embodiment of the present invention will be described with reference to FIGS.
[0060]
FIG. 5 is a plan view schematically showing an illumination device according to the third embodiment of the present invention. FIG. 6 is a cross-sectional view schematically showing the display device according to the embodiment.
[0061]
The display device according to the third embodiment of the present invention shown in FIGS. 5 and 6 has an upper pattern surface 37U and a lower pattern surface 37S (paper in FIG. 5) which are upper and lower surfaces of the linear light guide 32 in FIG. An upper reflection groove 38UA and a lower reflection groove 38SB are formed on both the front and back surfaces, and point light sources 31A and 31B made of LEDs are provided at both ends of the linear light guide 32, respectively. Light is incident on both ends of the body 32.
[0062]
On the upper pattern surface 37U, a plurality of upper reflection grooves 38UA are formed in the longitudinal direction so that an angle formed by the upper side of the light output surface 39 on the point light source 31A side is α. The angle α is substantially normal to the light output surface 39 when the main component light from the point light source 31A parallel to the longitudinal direction of the linear light guide 32 is reflected by the light source side surface of the upper reflection groove 38UA. It is formed at approximately 45 ° so as to exit from the light exit surface 39.
[0063]
In the lower pattern surface 37S, a plurality of lower reflection grooves 38SB are formed in the longitudinal direction so that an angle formed by the base of the light exit surface 39 on the point light source 31B side is α. The angle α is such that the main component light from the point light source 31B that is parallel to the longitudinal direction of the linear light guide 32 is reflected by the light source side surface of the lower reflection groove 38SB, and is approximately normal to the light exit surface 39. It is formed at approximately 45 ° so as to exit from the light exit surface 39.
[0064]
According to this configuration, the emitted light emitted from the light exit surface 39 can have high brightness, and the light use efficiency of incident light can be improved. Moreover, the emitted light from the linear light guide light output surface 39 can be made uniform over the entire longitudinal direction.
[0065]
In the present invention, first and second point light sources 31A and 31B, a linear light guide 32, and a light guide plate 4 are provided. The linear light guide 32 faces the first light incident surface 34 on which the light emitted from the first point light source 31A is incident, and the first light incident surface 34, and is emitted from the second point light source 31B. A second light incident surface 35 on which the incident light is incident, and a light exit surface 39 that is orthogonal to the plurality of light incident surfaces 34, 35 and emits the light incident on the plurality of light incident surfaces 34, 35 as linear light, The upper side of the light incident surfaces 34 and 35 and the upper side of the light exit surface 39 are formed, and the angle formed on the first point light source 31A side with the upper side of the light exit surface 39 is formed to be approximately 45 ° and arranged regularly. The angle formed on the second point light source 31B side between the first pattern surface (upper pattern surface) 37U having a plurality of grooves 38UA and the bottom of the light exit surface 39 facing the first pattern surface 37U is approximately 45 °. A second pattern surface (lower pattern) having a plurality of grooves 38SB formed and regularly arranged. 37S). In the light guide plate 4, the light emitted from the linear light guide 32 is incident from an incident surface 41 formed of one end surface, and the light incident on the incident surface 41 is reflected by a first main surface 47 in which a plurality of grooves 44 are formed. Then, the light is emitted while being dispersed in a plane from the second main surface 42. The first pattern surface 37U of the linear light guide 32 and the first main surface 47 of the light guide plate 4 are arranged on the same side.
[0066]
<Fourth embodiment>
Next, an illuminating device according to a fourth embodiment of the present invention will be described with reference to FIG.
[0067]
FIG. 7 is a plan view schematically showing an illumination apparatus according to the fourth embodiment of the present invention. The first pattern surface (lower pattern surface) 37S of the linear light guide 32 has a plurality of grooves 38SA formed with an angle α formed on the first point light source 31A side with the lower side of the light output surface 39 at approximately 45 °. Have. The second pattern surface (upper pattern surface) 37U of the linear light guide 32 includes a plurality of grooves 38UB formed with an angle α formed on the second point light source 31B side with the upper side of the light output surface 39 at approximately 45 °. Have. And the 1st pattern surface 37S of the linear light guide 32 and the 1st main surface 47 of the light-guide plate 4 are arrange | positioned on the opposite side.
[0068]
Other configurations and effects are the same as those of the third embodiment, and thus description thereof is omitted.
[0069]
FIG. 8 is a schematic diagram showing the angular distribution of outgoing light from the linear light guide according to the present invention. In FIG. 8, the angular distribution of the emitted light from the linear light guide 32 is schematically shown at three points near the light incident surface 34, near the center, and near the end surface 35 opposite to the light incident surface 34. According to the present invention, the angular distribution of the emitted light from the linear light guide 32 is substantially constant regardless of the location, and is substantially symmetric in the normal direction of the light exit surface 39. The angular distribution of the emitted light also exists in other parts other than the above three points.
[0070]
Since other configurations, operations, and effects are the same as those of the first embodiment shown in FIGS. 1 to 3, detailed descriptions thereof are omitted to avoid duplication.
[0071]
In these embodiments, the incident surface 41 of the light guide plate 4 is formed into a rough surface. The incident surface 41 can be formed into a rough surface with minute irregularities formed by die cutting, spray painting, embossing, etc., thereby diffusing the light incident on the light guide plate 4 and viewing angle characteristics. And the light emitted from the light guide plate 4 can be more evenly dispersed.
[0072]
In each of the above embodiments, the lighting device 2 is used as a front light. However, these lighting devices 2 can be used as a backlight.
[0073]
【The invention's effect】
In the present invention according to claim 1, since the linear light guide is formed integrally with the light guide plate, the positional relationship between the linear light guide and the light guide plate is not shifted.
[0074]
Further, since an air layer is interposed between the linear light guide and the light guide plate over substantially the entire length of the linear light guide, light incident from one end of the linear light guide is linearly guided. As a result of being reflected on the light exit surface of the body and being averagely dispersed and reaching the other end side, the light dispersed on the average from the linear light guide can be incident on the incident surface of the light guide plate. Generation of bright lines and bright parts can be prevented.
[0075]
Further, a plurality of grooves are formed in the pattern surface of the linear light guide and the first main surface of the light guide plate, and the pattern surface of the linear light guide and the first main surface of the light guide plate are the same surface side or opposite surfaces. Therefore, the light utilization efficiency of the incident light can be improved, and the light emitted from the light output surface of the linear light guide can be made uniform over the entire longitudinal direction.
[0076]
In particular, when the pattern surface of the linear light guide and the first main surface of the light guide plate are arranged on the same side, there is no need to complicate the mold structure, so the cost is reduced and the assembly man-hour is reduced. Productivity can be improved.
[0077]
In the present invention according to claim 2, a plurality of grooves are regularly arranged on the pattern surface of the linear light guide, and an angle formed on the point light source side between the grooves and one side of the light exit surface is approximately 45 °. Since the pattern surface on which the plurality of grooves of the linear light guide are formed and the first main surface on which the plurality of grooves of the light guide plate are formed are arranged on the same surface side or the opposite surface side. Further, the light utilization efficiency of the incident light can be further improved, and the light emitted from the light exit surface of the linear light guide can be made uniform over the entire longitudinal direction.
[0078]
The present invention according to claim 3 includes a linear light guide having a plurality of point light sources and a plurality of pattern surfaces, and a light guide, and the first pattern surface of the linear light guide and the first main of the light guide plate. Since the surfaces are arranged on the same surface side or the opposite surface side, the light utilization efficiency of incident light is further improved, and the light emitted from the light emitting surface of the linear light guide is uniform over the entire longitudinal direction. In addition, the emitted light emitted from the light exit surface can be made high brightness.
[0079]
In the present invention according to claim 4, since the incident surface of the light guide plate is formed into a rough surface, the light incident on the incident surface is provided with a scattering property, and the light having the average viewing angle characteristic is contained in the light guide plate. As a result of the incidence, the light emitted from the light guide plate is more evenly distributed in a plane, and the uniformity of image quality can be improved.
[0080]
The present invention according to claim 5 can provide a display device having the above effects.
[Brief description of the drawings]
FIG. 1 is a front view schematically showing an illumination device according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically showing the display device according to the first embodiment of the invention.
FIG. 3 is a cross-sectional view schematically showing the shape of a reflection groove of the linear light guide according to the embodiment of the present invention.
FIG. 4 is a front view schematically showing an illumination apparatus according to a second embodiment of the present invention.
FIG. 5 is a front view schematically showing an illumination apparatus according to a third embodiment of the present invention.
FIG. 6 is a cross-sectional view schematically showing a display device according to a third embodiment of the present invention.
FIG. 7 is a front view schematically showing an illumination device according to a fourth embodiment of the present invention.
FIG. 8 is a schematic diagram showing an angular distribution of light rays emitted from a linear light guide according to the present invention.
FIG. 9 is a cross-sectional view schematically showing a conventional display device.
FIG. 10 is a front view schematically showing a conventional lighting device.
FIG. 11 is a front view schematically showing a conventional linear light source.
FIG. 12 is an enlarged cross-sectional view schematically showing a conventional linear light source.
FIG. 13 is a schematic diagram showing an angular distribution of light rays emitted from a linear light guide according to a conventional technique.
[Explanation of symbols]
1 Non-luminous display means
2 Lighting equipment
3 Linear light source
4 Light guide plate
5 Air layer
6 Anti-reflective coating
7 Reflector
31 point light source
32 Linear light guide
34 Light entrance
35 End face opposite to light entrance
37 Pattern surface of linear light guide
38 Reflective groove of linear light guide
39 Light emitting surface
41 Incident surface
42 Main surface
43 End face opposite to the entrance face
44 Groove of light guide plate
45 Reflective surface of light guide
46 Translucent surface
47 1st surface
101 Non-light emitting display means
102 Illumination device
103 Linear light source
104 Light guide plate
106 Anti-reflective coating
107 reflector
131 Point light source
132 Linear light guide
133 Reflective surface of linear light guide
134 Incident surface
139 Light emitting surface
141 Incident surface
142 Back
143 End surface opposite to the incident surface
145 Reflective surface of light guide plate
146 Translucent surface
147 surface

Claims (5)

A point light source,
  A light incident surface on which light emitted from the point light source is incident; a light exit surface that is orthogonal to the light incident surface and emits light incident on the light incident surface as linear light; and one side of the light incident surface And a linear light guide comprising a pattern surface on which a plurality of grooves are formed,
  Light emitted from the linear light guide is incident from an incident surface consisting of one end surface, the light incident on the incident surface is reflected by the first main surface on which a plurality of grooves are formed, and planar from the second main surface. A light guide plate that is dispersed and emitted to a lighting device,
  The plurality of grooves are regularly arranged on the pattern surface of the linear light guide, and an angle formed on the point light source side between the grooves and one side of the light output surface is formed to be approximately 45 °. ,
  The illumination device, wherein the pattern surface of the linear light guide and the first main surface of the light guide plate are arranged on the same surface side or on the opposite surface side. First and second point light sources;
  A first light incident surface on which light emitted from the first point light source is incident; and a second light incident on which light emitted from the second point light source is incident, facing the first light incident surface. A light surface, a light exit surface that is orthogonal to the plurality of light entrance surfaces, and emits light incident on the plurality of light entrance surfaces as linear light; A first pattern surface having a plurality of grooves formed at an angle of approximately 45 ° with the upper side of the light output surface on the first point light source side, and opposed to the first pattern surface; A linear light guide comprising a second pattern surface having a plurality of grooves formed at an angle of approximately 45 ° with the bottom of the surface on the second point light source side;
  Light emitted from the linear light guide is incident from an incident surface consisting of one end surface, the light incident on the incident surface is reflected by the first main surface on which a plurality of grooves are formed, and planar from the second main surface. A light guide plate that is dispersed and emitted to a lighting device,
  The lighting device, wherein the first pattern surface of the linear light guide and the first main surface of the light guide plate are disposed on the same surface side or on the opposite surface side. 2. The linear light guide is integrally formed with the light guide plate so as to face the incident surface of the light guide plate through an air layer over substantially the entire length thereof. 2. The lighting device according to 2.   The lighting device according to claim 1, wherein the incident surface of the light guide plate is formed into a rough surface.   5. A display device comprising: the illumination device according to claim 1; and a non-light emitting display unit disposed on a second main surface side of the light guide plate.

Images