JP4629426B2 - Light guide and flat illumination device - Google Patents

Description

  The present invention provides a light guide capable of obtaining a high-intensity flat illumination device by forming a plurality of incident surface portions parallel to one side surface portion on the back surface portion of the light guide and providing a light source in the vicinity of each incident surface portion. The present invention relates to a body and a flat lighting device.

As a conventional light guide, one having a plurality of prism-shaped grooves on the back surface is known. Further, as the distance from the light source unit or the like increases, the grooves are denser, and the portion near the light source unit is brighter and the distant portion is prevented from being darkened, and the luminance of the entire light guide is made uniform.
JP 09-184920 A JP-A-10-339815

  The above-described conventional light guide has a plurality of prism-shaped grooves on the back surface, and the grooves are denser the further away from the light source unit, the closer to the light source unit is brighter and the farther part is darker. Although the brightness of the entire light guide is made uniform, the light guided from the incident part at one end of the light guide into the light guide travels in the opposite direction of the incident part toward the first groove. The reflected light is reflected and refracted and deflected. However, the light on the same light trace as the light directed to the first groove does not exist in the next groove, and this tendency becomes stronger as it goes in the opposite direction of the incident part, and it is effective for the groove near the incident part. Only the light having an incident angle different from the incident angle with respect to the groove acting on the groove affects the light, and there is a problem that the probability amount of the light effectively acting on the groove is reduced.

  The present invention has been made to solve the above-described problems, and at least one side surface portion of the light guide body is an incident end surface portion that guides light, and the back surface portion has a plurality of incident lights parallel to the incident end surface portion. The surface portion has a plurality of inclined surface portions connected to the incident surface portion, and light can be guided from the incident end surface portion and each incident surface portion, and light reflected by the inclined surface portion toward the surface portion is critical at the surface portion. Provided are a light guide and a flat illumination device capable of obtaining emitted light with high brightness because the incident angle to the surface portion that breaks the angle can be deflected and emitted from the surface portion with a taper leak to the outside. There is.

In the light guide according to claim 1 of the present invention, the side surface portion at one end or the side surface portions at both ends form an incident end surface portion that guides light, and the back surface portion mutually communicates with a plurality of incident surface portions that guide light in parallel to the incident end surface portion. entrance end face and incident face and having a plurality of inclined surfaces that connect to the the incident face may have a plurality of continuous and concave circular arc shape, a plurality of successive incident end face and the incident end face adjacent A continuous arc-shaped portion of the concave arc shape and a maximum arc portion of the concave arc shape are shifted from each other .

The light guide according to claim 1 is configured such that one side surface portion or both side surface portions form an incident end surface portion that guides light, and a rear surface portion and a plurality of incident surface portions that guide light parallel to the incident end surface portion. a plurality of incident end face and incident face and having an inclined surface, have a plurality of continuous and concave circular arc shape, a plurality of successive concave arc shape of the incident end face and the incident end face adjacent to connect to preparative Since the continuous arc portion and the concave arc-shaped maximum arc portion are displaced from each other, light can be guided from the incident end face part and each incident face part, and the light reflected by the inclined face part on the surface part is Since the incident angle to the surface portion that breaks the critical angle can be deflected and emitted from the surface portion with a taper leak to the outside, it can be emitted with high brightness. Also, for light sources such as semiconductor light-emitting elements having directivity, a concave arc shape faces each of the light sources so that when light enters the light guide body, it spreads through the light guide body. be able to.
Furthermore, light from light sources adjacent to each other is difficult to overlap, and the entire light guide can be brightened more uniformly.
Further, even if a light source such as an RGB semiconductor light emitting element (red, green, blue) is provided at a position corresponding to each concave circular arc shape of the incident end face part and the incident face part, RGB light is more easily mixed by mutual displacement. Become.

Further, the light guide according to claim 2 is characterized in that the concave arc shape has a plurality of lens arrays or prisms on the inner surface side of the arc.

Since the concave arc shape has a plurality of lens arrays or prisms on the inner surface side of the arc, the light guide according to claim 2 is guided by the lens array or prism inside the concave arc shape facing each light source. When light enters the inside of the light body, the light is once condensed to be further spread light, and can also travel through the light guide body with the spread of the entire concave arc shape.

Furthermore, the flat illumination device according to claim 3 includes a plurality of light sources,
It consists of a front surface part that emits light, a back surface part located on the opposite side of this front surface part, and a side surface part connected to these front surface part and back surface part. None the end face, the incident end face and incident face with the rear surface portion has a plurality of inclined surfaces that connect to the plurality of entrance surface for guiding light parallel to the incident end face and the incident face each other, continue plurality of communication concave arc shape have a, a light guide that has deviated from each other and a continuous portion and a maximum arc portion of the concave arc shape of a plurality of successive concave arc shape of the incident end face and the incident end face adjacent to the,
A reflector covering other than the surface portion;
It includes at least a case for housing the plurality of light sources, the light guide, and the reflector.

The flat illumination device according to claim 3 includes a plurality of light sources,
It consists of a front surface part that emits light, a back surface part located on the opposite side of this front surface part, and a side surface part connected to these front surface part and back surface part. None the end face, the incident end face and incident face with the rear surface portion has a plurality of inclined surfaces that connect to the plurality of entrance surface for guiding light parallel to the incident end face and the incident face each other, continue plurality of communication concave arc shape have a, a light guide that has deviated from each other and a continuous portion and a maximum arc portion of the concave arc shape of a plurality of successive concave arc shape of the incident end face and the incident end face adjacent to the,
A reflector covering other than the surface portion;
Since at least the light source, the light guide and the case for housing the reflector are provided, the light is guided from the light source near the incident end face and each incident face and reflected by the inclined face toward the surface. Since the incident angle to the surface portion that breaks the critical angle at the surface portion can be deflected and emitted from the surface portion with a taper leak, the emitted light with high luminance can be obtained.

The flat illumination device according to claim 4 is characterized in that the light source comprises a semiconductor light emitting element.

Planar illumination device according to claim 4, since the light source comprises a semiconductor light emitting element, by providing the semiconductor light-emitting element in the vicinity of each concave arcuate multiple, it can lead to more light to the light guide body .

As described above, in the light guide according to claim 1, the side surface portion at one end or the side surface portions at both ends forms an incident end surface portion that guides light, and the back surface portion includes a plurality of incident surface portions that guide light in parallel to the incident end surface portion. When the incident end face and incident face and having a plurality of inclined surfaces that connect to the the incident face each other, have a plurality of continuous and concave circular arc shape, the incident end face and the incident end a plurality of surface portions adjacent to each other Since the continuous concave arc-shaped continuous portion and the concave arc-shaped maximum arc portion are displaced from each other, light can be guided from the incident end surface portion and each incident surface portion and reflected by the inclined surface portion toward the surface portion. Light can be emitted with a taper leak from the surface portion to the outside by deflecting the incident angle to the surface portion that breaks the critical angle at the surface portion, so that emitted light with high luminance can be obtained.
Therefore, even with a large light guide, it is possible to obtain outgoing light with higher brightness than before.
Also, for light sources such as semiconductor light-emitting elements having directivity, a concave arc shape faces each of the light sources so that the light travels through the light guide body when the light enters the light guide body. be able to.
Therefore, the light can reach the entire light guide with a spread from the incident end face part and each incident face part.
Furthermore, light from light sources adjacent to each other is difficult to overlap, and the entire light guide can be brightened more uniformly.
Therefore, it is easy to see and high-luminance outgoing light can be obtained.
Further, even if a light source such as an RGB semiconductor light emitting element (red, green, blue) is provided at a position corresponding to each concave circular arc shape of the incident end face part and the incident face part, RGB light is more easily mixed by mutual displacement. Become.
Therefore, high brightness white light can be obtained as the entire light guide.

In addition, since the light guide according to claim 2 has a concave arc shape having a plurality of lens arrays or prisms on the inner surface side of the arc, the light guide is opposed to each light source by a lens array or prism inside the concave arc shape. When the light enters the inside of the light guide, the light is once condensed, and further spreads, and the entire concave arc shape can also travel through the light guide.
Therefore, light can be uniformly distributed throughout the light guide.

Furthermore, the flat illumination device according to claim 3 includes a plurality of light sources,
It consists of a front surface part that emits light, a back surface part located on the opposite side of this front surface part, and a side surface part connected to these front surface part and back surface part. None the end face, the incident end face and incident face with the rear surface portion has a plurality of inclined surfaces that connect to the plurality of entrance surface for guiding light parallel to the incident end face and the incident face each other, continue plurality of communication concave arc shape have a, a light guide that has deviated from each other and a continuous portion and a maximum arc portion of the concave arc shape of a plurality of successive concave arc shape of the incident end face and the incident end face adjacent to the,
A reflector covering other than the surface portion;
Since at least the light source, the light guide and the case for housing the reflector are provided, the light is guided from the light source near the incident end face and each incident face and reflected by the inclined face toward the surface. Since the incident angle to the surface portion that breaks the critical angle at the surface portion can be deflected and emitted from the surface portion with a taper leak, the emitted light with high luminance can be obtained.
For this reason, it is possible to obtain high-luminance outgoing light with a large light guide, even with a flat illumination device larger than the conventional one.

The planar lighting device according to claim 4, since the light source comprises a semiconductor light emitting element, by providing the semiconductor light-emitting element in the vicinity of each concave arcuate multiple, directing more light to the light guide body Can do.
Therefore, it is possible to obtain high-luminance outgoing light without luminance spots.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
In the present invention, at least one side surface portion forms an incident end surface portion that guides light, and the back surface portion includes a plurality of incident surface portions that are parallel to the incident end surface portion and a plurality of inclined surface portions that are connected to the incident surface portion. To construct a light guide. The light-emitting body includes a light guide, a plurality of light sources, a reflector that covers a portion other than the surface portion, and a case that houses the light guide, the plurality of light sources, and the reflector. And, according to the present invention, the light can be guided from the incident end face part or each incident face part by these configurations, and the light reflected in the surface part direction by the inclined surface part can break the critical angle at the surface part. Provided is a light guide and a flat illumination device capable of deflecting the incident angle to the surface part and emitting from the surface part by causing a taper leak to the outside and obtaining high-luminance outgoing light. It is.

Figure 1 is schematic perspective view of a planar lighting device according to the present invention, schematic cross-sectional view of the light guide body according to Figure 2 the present invention, FIG. 3 is substantially under a front view of a light guide according to the present invention, FIG. 4 (a ), (b) is substantially enlarged view of the entrance end face and incident surface of the light guide according to the present invention, FIG. 5 is substantially lower front view of the semiconductor light-emitting element placed state of the planar illumination device according to the present invention, FIG. 6 FIG. 7 is a schematic front view of the light emitting element mounted state of the flat illumination device according to the present invention, FIG. 7 is a schematic locus diagram of the light beam of the light guide according to the present invention, and FIG. 8 is the light beam of the light guide according to the present invention. 9 is a schematic locus diagram of light rays of the light guide according to the present invention , FIG. 10 is a schematic front view of the light guide according to the present invention, and FIG. 11 is a schematic diagram of the light guide according to the present invention. It is sectional drawing.

  As shown in FIG. 1, the flat illumination device 1 includes a light guide 2 having a plurality of incident surface portions 7 a and inclined surface portions 8 on the back surface portion 4, and an incident end surface portion 7 of the light guide 2 (example of FIG. 1). Then, the light source 10 provided in the vicinity of the opposite side surface portions) and the incident surface portion 7a, the reflector 11 surrounding the light guide body 2 other than the surface portion 3 (the emission surface portion), the light guide body 2 and the light source 10 This is a configuration comprising a case 12 that houses the reflector 11.

The light guide 2 is formed by molding with a transparent acrylic resin (PMMA), polycarbonate (PC) or the like having a refractive index of about 1.4 to 1.7. As shown in FIG. 2, a pair of opposite side surface portions 9 is used as an incident end surface portion 7 that guides light from the outside, and a plurality of incident surface portions 7 a that are parallel to the incident end surface portion 7 that similarly guides light from the outside are provided on the back surface portion 4. The incident end surface portion 7 has a plurality of inclined surface portions 8 connected to the incident surface portion 7a, and the two inclined surface portions 8 are connected to each other at the center position from both ends.
The inclination direction of the inclined surface portion 8 is bidirectional, and the thickness of the light guide 2 (distance between the front surface portion 3 and the back surface portion 4) decreases from the pair of incident end surface portions 7 at both ends toward the central direction.
The thickness (the distance between the front surface portion 3 and the back surface portion 4) of the light guide 2 is also reduced at the portion where the two inclined surface portions 8 are connected at the center position from the pair of incident end surface portions 7 at both ends. And the light guide | induced from these incident-end surface parts 7 and the incident surface part 7a goes to the center direction of the light guide 2. As shown in FIG.

Further, the light guide 2 of the present embodiment may be configured as shown in FIG. 10. The light guide 2 has a half configuration of the light guide 2 of FIG. 1, and one of the side surface portions 9 serves as an incident end surface portion 7 that guides light from the outside, and is opposite to the incident end surface portion 7. Is formed as a reflection end surface portion 6 that reflects light, and the back surface portion 4 is provided with a plurality of incident end surface portions 7 or a plurality of incident surface portions 7a parallel to the reflection end surface portion 6, and a plurality of incident end surface portions 7 are connected to the incident surface portion 7a. The inclined surface portion 8 is provided so that the inclined direction of the inclined surface portion 8 is provided in the same direction from the incident end surface portion 7 to the reflecting end surface portion 6, and the thickness of the light guide 2 increases as the distance from the incident end surface portion 7 or the incident surface portion 7a increases. Becomes thinner.

Further, the light guide 2 of the present embodiment can also be configured as shown in FIG. 11. The light guide 2B (2) has a pair of opposing side surface portions 9 as reflection end surface portions 6, and a plurality of incident surface portions 7a parallel to the reflection end surface portion 6 (side surface portion 9) are provided on the back surface portion 4. It has the some inclined surface part 8 connected to the surface part 7a, and the two inclined surface parts 8 are connected by the center position from both ends.
The inclination direction of the inclined surface portion 8 is bidirectional, and the thickness of the light guide 2 (distance between the front surface portion 3 and the back surface portion 4) increases from the pair of reflection end surface portions 6 at both ends toward the central direction.
The thickness of the light guide 2 (the distance between the front surface portion 3 and the back surface portion 4) is also thicker at the portion where the two inclined surface portions 8 are connected at the center position from the pair of reflection end surface portions 6 at both ends. And the light guide | induced from these incident-end surface parts 7 and the incident surface part 7a goes to the outer side direction (side part 9) of the light guide 2. FIG.

Although not shown in the drawing, the light guide of this example is made up of one half of a light guide 2B as shown in FIG. 11 , and one of the side surface portions 9 is used as an incident end surface portion 7 for guiding light from the outside. The opposite side opposite to the end face part 7 is a reflective end face part 6 that reflects light, and the back face part 4 is provided with a plurality of incident end face parts 7 or incident face parts 7a parallel to the reflective end face part 6, and the incident end face part 7 and A plurality of inclined surface portions 8 connected to the incident surface portion 7a can be provided, and the inclined direction of the inclined surface portion 8 from the incident end surface portion 7 to the reflective end surface portion 6 can be provided in the same direction. In this configuration, the thickness of the light guide 2B decreases as the distance from the incident end surface portion 7 or the incident surface portion 7a increases.

Further, as shown in FIG. 3 , the light guide 2 of the present example has a continuous concave arc formed on the incident end surface portion 7, the incident end surface portion 7 and the incident surface portion 7 a having a plurality of continuous concave arc shapes 7 b. The shape 7b and the continuous concave arc shape 7b applied to the incident surface portion 7a are in a staggered positional relationship, and the continuous concave arc shape 7b applied to the adjacent incident surface portions 7a are in a staggered positional relationship. You can also That is, in this configuration, the maximum arc portion of the continuous concave arc shape 7b of the incident end surface portion 7 and the maximum arc portion of the continuous concave arc shape 7b of the incident surface portion 7a are displaced from each other, and the incident surface portions 7a adjacent to each other. The maximum arc portion of the continuous concave arc shape 7b is shifted from each other and is at the same position parallel to the side surface portion 9.

  For this reason, it is possible to obtain outgoing light that is easy to see and has high luminance. For example, even if the light source 10 such as an RGB semiconductor light emitting element (red, green, blue) is provided at a position corresponding to each concave arc shape 7b of the incident end surface portion 7 and the incident surface portion 7a, the RGB light is more caused by the mutual displacement. It becomes easy to mix and white light with high brightness can be obtained as the entire light guide 2.

Further, although not shown here, in the shape of the light guide plate 2B in FIG. 11 , the incident surface portion 7a has a plurality of continuous concave arc shapes 7b as in FIG. 3, and is continuously applied to the incident surface portion 7a. It is also possible to adopt a configuration in which the continuous concave arc shape 7b in which the concave arc shape 7b is applied to the incident surface portions 7a adjacent to each other has a staggered positional relationship.
However, in the light guide 2B in FIG. 11 , the direction of the concave arc shape 7b is opposite to that in FIG .

Further, as shown in FIG. 4 , the light guide 2 and the light guide 2B of the present example have a plurality of lens arrays 7c (FIG. 4 (a) on the inside of the arc of the concave arc shape 7b of the incident end surface 7 and the incident surface 7a. )) or a plurality of prisms 7d (can be configured with FIG 5 (b).

  Therefore, when the light enters the light guides 2 and 2B by the lens array 7c or the prism inside the arc of the concave arc 7b facing each light source 10, the light is once condensed and further spread. It becomes light and can be evenly distributed to the entire light guides 2 and 2B with the spread of the entire concave arc shape 7b.

In the light guide 2 and the light guide 2B of the present example, the light incident from the incident end face part 7 or the incident face part 7a has a refraction angle γ of 0 ≦ | γ | ≦ Sin ⁻¹ (1 / n). It progresses in the light guide 2 and the light guide 2B in the range which satisfy | fills. For example, since the refractive index of acrylic resin, which is a resin material used for general light guide 2 and light guide 2B, is about n = 1.49, the incident light has a refraction angle γ = ± 42 °. It is in.

  Further, the light incident on the light guide 2 and the light guide 2B within the range of the refraction angle γ ± 42 ° is generated between the light guide 2 and the light guide 2B and the air layer (refractive index is n = 1). At the boundary surface, the critical angle can be expressed by the equation Sinα = (1 / n). For example, since the refractive index of acrylic resin, which is a resin material used for the general light guide 2 and light guide 2B, is about n = 1.49, the critical angle α is α = 42 °.

Furthermore, although not shown in the drawings, the light guide 2 and the light guide 2B of this example can be configured such that the surface portion 3 and the back surface portion 4 are processed with fine irregularities 13 such as an arc shape or a groove shape.
With this configuration, the light from the light source 10 is guided into the light guide 2 and the light guide 2B from the incident end surface portion 7 and the incident surface portion 7a of the light guide 2 and the light guide 2B. As a result, the light existing in the light guide 2 and the light guide 2B should be flat with a constant thickness of the light guide 2 and the light guide 2B, and have no irregularities 13 such as arcs or grooves. For example, the light guide 2 or the light guide 2B does not leak to the outside, but is reflected or refracted by the concave and convex portions 13 such as the arc shape or the groove shape as described above, and is reflected by the reflection of a part of the light. The light deflected by the angle or the light reaching the uneven portion 13 such as an arc shape or a groove shape is refracted by the exit surface portion (surface portion 3), and the surface portion 3 (exit surface portion) of the light guide 2 or the light guide 2B. ) Can be emitted.

Next will be described a light trajectory of the light guide body 2 and the light guide body 2B in FIG.
The light source 10 is provided in the vicinity of the incident end surface portion 7 and the incident surface portion 7a. The light beam L guided from the light source 10 from the incident end surface portion 7 and the incident surface portion 7a is reflected by the inclined surface portion 8 and travels toward the surface portion 3. Then, the reflected light LR reflected by the inclined surface portion 8 reaches the surface portion 3, is refracted by the fine arc-shaped protrusions 13 provided on the surface portion 3, and is emitted to the outside as emitted light Lo.

  Further, the light beam L1 guided from the light source 10 from the incident end surface portion 7 and the incident surface portion 7a is reflected by the inclined surface portion 8 and travels toward the surface portion 3. The reflected light L1R reflected by the inclined surface portion 8 reaches the front surface portion 3, is totally reflected by the front surface portion 3, and travels toward the back surface portion 4 (inclined surface portion 8). The reflected light L <b> 1 </ b> R <b> 2 totally reflected by the surface portion 3 is again reflected by the inclined surface portion 8 and travels in the direction of the surface portion 3. The reflected light L1R3 reflected again by the inclined surface portion 8 is repeatedly reflected twice by the inclined surface portion 8 and the deflection angle toward the surface portion 3 gradually increases. When the reflected light L1R3 reaches the surface portion 3, the incident angle breaks the critical angle α ( Taper leak), the critical angle α is broken, and the light is emitted from the surface portion 3 to the outside as emitted light Lo.

In addition, in the light guide 2B of FIG. 11 , the incident end face part 7 and the light source 10 corresponding to the incident end face part 7 do not exist, but the light trajectory in the light guide 2B is the same as described above. Therefore, explanation is omitted here.
Further, FIG. 10 in which the light guide 2 is halved and the light guide 2B in a half are the same as those described above, and thus description thereof is omitted here.

  Thus, since the light guide 2 and the light guide 2B have a plurality of incident surface portions 7a, light can be guided from the incident end surface portion 7 and each incident surface portion 7a. Moreover, the light reflected by the inclined surface portion 8 in the direction of the surface portion 3 deflects the incident angle to the surface portion 3 so as to break the critical angle at the surface portion 3, and causes a taper leak from the surface portion 3 to the outside to be emitted. can do. For this reason, the emitted light with high brightness can be obtained, and even with the large light guide 2 and the light guide 2B, the emitted light with higher brightness than before can be obtained.

In particular, as shown in FIG. 1, it has incident end surface portions 7 at both ends (a pair of side surface portions 9), and has a plurality of inclined surface portions 8 connected to the incident surface portion 7a. One of the red light emission using the light guide 2 to the inclined surface portion 8 is connected, a green light emitting, when a light source 10 to the semiconductor light emitting element to the three primary colors emitting blue light, as shown in Figure 7, the incident end face 7 And the light beam incident from the incident surface portion 7a is emitted to the outside from the surface portion 3 facing the center of the light guide 2 from both ends (the light from the left light source 10 is emitted from the right surface portion 3 and the right light source The light from 10 is emitted from the surface portion 3 on the left side). For this reason, the light source 10 is blinked so as to alternate the left and right lighting times from the center position of the light guide 2 (when the right light source 10 is turned on, the light is emitted from the left surface portion 3 of the light guide 2 and left light source 10 is turned on. The light is emitted from the right surface portion 3 of the light guide 2 when the light 10 is turned on. By driving the liquid crystal of a liquid crystal display device (not shown) alternately on the left and right on these emission sides (the emitted light and the liquid crystal are synchronized), a stereoscopic image (3D) is generated. It can be reproduced.

As shown in FIG. 8 , the light guide 2 and the light guide 2B emit light in a cylindrical shape, for example, when the light source 10 is a cold cathode tube (CCFL), the cold cathode tube (CCFL) is cylindrical. Therefore, not only the light beam L7 from the incident end surface portion 7 and the incident surface portion 7a of the light guide 2 and the light guide 2B but also the inclined surface portion 8 that connects the light Ls from the cold cathode fluorescent lamp (CCFL) to the incident surface portion 7a. The transmitted light L8 can be guided into the light guide 2 and the light guide 2B through the back surface (through the back surface portion 4). As a result, it is possible to obtain high-luminance outgoing light without luminance spots.

Furthermore, as shown in FIG. 9 , when the light source 10 is a semiconductor light emitting element 10L such as an LED or a laser, the light guide 2 and the light guide 2B are arranged near the plurality of concave arc shapes 7b. The semiconductor light emitting element 10L is provided. As a result, the light from the light source 10L travels in the light guide 2 and the light guide 2B as a light beam L7 spread by the concave arc shape 7b which is a concave arc shape. As a result, a lot of light can be guided into the light guide 2 and the light guide 2B from many concave arc shapes 7b.
Therefore, since each of the concave arc shapes 7b is adjacent to each other even in the light source 10 such as the high-intensity outgoing light having no luminance unevenness or the RGB semiconductor light emitting element (red, green, blue), the light of each color is mixed and colored. Spotless white light can be obtained.

The light source 10 includes a cold cathode fluorescent lamp (CCFL) or a semiconductor light emitting element (such as an LED or a laser). Cold cathode fluorescent lamps (CCFLs) are provided with electrodes on both ends of a thin quartz glass tube, etc., and are colored by a fluorescent material applied to the inside of the tube and applied to almost the entire wavelength range of color temperature including ultraviolet rays and RGB. It emits light in a cylindrical shape.
The semiconductor light-emitting element is a high-intensity light-emitting element such as a quaternary compound or a compound such as InGaAlP-based, InGaAlN-based, or InGaN-based, and an organic metal on a substrate such as Al ₂ O ₃ , InP sapphire, SiC, GaAs, ZnSe Manufactured by a vapor deposition method or the like, three primary colors of red light emission, green light emission, and blue light emission can be used. These semiconductor light emitting elements are made of a material made of In ₂ O ₃ , SnO ₂ , ITO or the like, and are provided with a transparent electrode by sputtering, vacuum vapor deposition, chemical vapor deposition or the like.

Furthermore, it is also possible to use a light emission color that is a mixture of a light emission color from a wavelength conversion material (YAG system) that is excited by light from the semiconductor light emitting element and a light emission color of the semiconductor light emitting element itself.
In this case, for example, a transparent adhesive mixed with a wavelength conversion material (YAG system) that is excited by light from a blue light emitting InGaAlN based semiconductor light emitting element and emits yellow or orange light is provided around the semiconductor light emitting element. It is possible to obtain a white emission color mixed by the blue emission color of the semiconductor light emitting element itself and the emission color such as yellow or orange from the wavelength conversion material.

Further, as shown in FIG. 5 , the light source 10 has three types of light sources 10 in the vicinity of the concave arc shape 7b in the order of red light emission 10R, green light emission 10G, and blue light emission 10B in each concave arc shape 7b of the incident surface portion 7a. The light emission color of the light source 10 provided in the first concave arc shape 7b of the adjacent incident surface portion 7a can be sequentially changed and placed.
In FIG. 5 , the red light emission 10R, the green light emission 10G, and the blue light emission 10B are arranged in order from the upper left part of the concave arc shape 7b to the lower side, and the red light emission 10R and the green light are arranged from the upper left part of the concave arc shape 7b to the right. Light emission 10G and blue light emission 10B are arranged in this order. That is, three types of light sources (red light emission 10R, green light emission 10G, and blue light emission 10B) are shifted in the vertical and horizontal directions from the concave arc shape 7b at the corner end of the light guide 2 so that the red light emission 10R and the green light emission 10G. The blue light emission 10B is selectively arranged.

In addition, as shown in FIG. 5 , the light source 10 has a white light emission 10W as a whole as a set of three types of light sources 10 in the order of red light emission 10R, green light emission 10G, and blue light emission 10B in each concave arc shape 7b of the incident surface portion 7a. It can also be set as the structure which radiate | emits this light.

These light sources 10 have a continuous concave arc shape 7b in which the continuous concave arc shape 7b applied to the incident surface portion 7a having the plurality of continuous concave arc shapes 7b shown in FIG. 3 is applied to the adjacent incident surface portions 7a. And can be arranged in a staggered relationship.

The reflector 11 has a substantially circular arc shape 11b at both ends, and the light source 10 and the light source 10 provided in the vicinity of the light incident surface 7 and the light source 10 provided near the light incident surface 7 are encased from the vicinity of the light incident surface 7. The leaked light is returned to the light guide 2 and the light guide 2B again.
Furthermore, the light guide 2 and the light guide 2B are again subjected to light leaked from the vicinity of the light source 10 provided in the vicinity of the incident surface portion 7a of the light guide 2 and the light guide 2B and light leaked from the back surface portion 4 (inclined surface portion 8). Return to.

The reflector 11 is made by molding a thin metal plate having excellent reflectivity such as aluminum or stainless steel.
Further, it is made by injection molding a thermoplastic resin mixed with a white material such as titanium oxide, or by depositing metal such as aluminum on the thermoplastic resin, or by laminating a metal foil.

  The case 12 is made of an insulating resin material such as a thin metal plate having excellent reflectivity such as aluminum or stainless steel, a modified polyamide, polybutylene terephthalate, nylon 46, an aromatic polyester, or the like, and has a light reflectivity. In order to improve the light-shielding property, white powder such as titanium oxide is mixed into a shape having an upper opening by heat injection molding.

  Further, the case 12 may be directly used by omitting the reflector 11 when the reflector 11 is placed on the bottom 12B, or when the reflector 12 is made of a thin metal plate having excellent reflectivity.

As described above, according to the light guide of the present invention and the flat illumination device using the light guide, the side surface portion at one end or the side surface portions at both ends form the incident end surface portion that guides light, and the back surface portion is the incident end surface. incident end face and the incident face and having a plurality of inclined surfaces that connect to the plurality of entrance surface and the incident surface portion mutually parallel guiding light to the part has a plurality of successive concave arc shape, next to each other The light is guided from the incident end face part and each of the plurality of incident face parts by a configuration in which the contiguous incident end face part and a plurality of continuous concave arc-shaped continuous parts of the incident end face part are shifted from the maximum arc part of the concave arc shape. be able to. Further, the light reflected in the direction of the surface by each of the plurality of inclined surfaces can deflect the incident angle to the surface so as to break the critical angle at the surface, and can be emitted from the surface by causing a taper leak to the outside. Therefore, outgoing light with high luminance can be obtained, and outgoing light with higher luminance than before can be obtained even with a large light guide.

  It is suitable for backlights for large liquid crystal display devices and the like, and since it has particularly high luminance, it can sufficiently cope with places where external light such as car navigation is present.

1 is a schematic perspective view of a flat illumination device according to the present invention. It is a schematic sectional drawing of the light guide which concerns on this invention. It is a substantially lower front view of the light guide which concerns on this invention. It is a substantially enlarged view of the incident end face part and the incident face part of the light guide according to the present invention. It is a substantially lower front view of the semiconductor light emitting element mounting state of the flat illumination device according to the present invention. It is a substantially lower front view of the semiconductor light emitting element mounting state of the flat illumination device according to the present invention. It is an approximate locus figure of a light ray of a light guide concerning the present invention. It is an approximate locus figure of a light ray of a light guide concerning the present invention. It is a substantially lower front view of the light guide which concerns on this invention. It is a substantially lower front view of the light guide which concerns on this invention. It is a schematic sectional drawing of the light guide which concerns on this invention.

DESCRIPTION OF SYMBOLS 1 Plane illuminating device 2, 2B Light guide 3 Front surface part 4 Back surface part 6 Reflective end surface part 7 Incident end surface part 7a Incident surface part 7b Concave circular arc shape 7c Lens array 7d Prism 8 Inclined surface part 9 Side surface part 10, 10L Light source 10R Red light emission 10G Green light emission 10B Blue light emission 11 Reflector 11b Arc shape 12 Case 12b Bottom 13 Fine irregularities α Critical angle γ Refraction angle n Refractive index L, L1, L1R light beam L1R2, L1R3 light beam Lo, LR, Ls light beam L7 light beam L8 Transmitted light

Claims (4)

A light guide body comprising a front surface portion for emitting light, a back surface portion located on the opposite side of the front surface portion, and a side surface portion connected to the front surface portion and the back surface portion,
A side surface portion at one end or a side surface portion at both ends forms an incident end surface portion that guides light, and the rear surface portion includes a plurality of incident surface portions that guide light in parallel to the incident end surface portion and a plurality of inclined surfaces that are connected to the incident surface portion. the incident end face and the incident face and having the door is to have a plurality of continuous and concave arcuate shape, successive plurality of successive said concavely curved shape of the incident end face and the incident end face adjacent The light guide body, wherein the portion and the maximum arc portion of the concave arc shape are displaced from each other . The light guide according to claim 1, wherein the concave arc shape has a plurality of lens arrays or prisms on an inner surface side of the arc. Multiple light sources;
It consists of a front surface part that emits light, a back surface part located on the opposite side of this front surface part, and a side surface part connected to these front surface part and back surface part. The back surface portion has a plurality of incident surface portions for guiding light parallel to the incident end surface portion and a plurality of inclined surfaces connected to the incident surface portion, and the incident end surface portion and the incident surface portion are: have a plurality of continuous and concave circular arc shape, the incident end face and the maximum arc portion and is displaced from each other in a plurality of successive said concave arc shape with successive portions of the concavely curved shape of the incident end face adjacent and Tei Ru light guide body,
A reflector covering other than the surface portion;
A flat illumination device comprising at least a case for housing the plurality of light sources, the light guide, and the reflector. 4. The flat illumination device according to claim 3, wherein the light source comprises a semiconductor light emitting element.

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