JPWO2008047794A1 - LIGHTING DEVICE AND IMAGE DISPLAY DEVICE USING THE SAME - Google Patents

Abstract

High brightness, particularly high front brightness, high light utilization efficiency, easy device enlargement, elimination of uneven brightness in the front direction without strict alignment between the light source and other components, and wide viewing angle An object of the present invention is to provide a lighting device that is advantageous for productivity and thinning. The first light direction control means narrows the viewing angle in the width direction and concentrates the front energy in the front direction, and the second light direction control means disposed on the exit surface of the first light direction control means has a height field of view. The above-mentioned problem is solved by concentrating the angle and concentrating the front energy in the front direction, and at the same time appropriately widening the viewing angle in the width direction narrowed by the first light beam control means.

Description

  The present invention relates to an illuminating device including a plurality of linear light sources and an image display device using the illuminating device, and particularly, an illuminating signboard device and a liquid crystal display that are large and require high luminance, luminance uniformity, and high viewing angle. The present invention relates to an illuminating device and an image display device that are preferably used in a device or the like.

  Taking an illumination device for an image display device as an example, an edge light system that guides light of a light source arranged on the side edge of the light guide plate in the front direction with the light guide plate and makes it uniform with a diffusion sheet, and on the back side of the illumination surface There is a direct system in which a light source is arranged and light is made uniform by a light diffusion plate.

  In the direct method, since the light source is provided on the side surface of the apparatus, the edge light method, which is advantageous by providing the light source at the side edge, has been mainly used in fields where thinness is required such as mobile phones and mobile personal computers.

  On the other hand, in recent years, there has been an increasing demand for larger displays and higher brightness mainly in the market of televisions and personal computer monitors. With the increase in size, in the edge light system, since the ratio of the length of the peripheral portion to the display area where the light source can be arranged decreases, sufficient luminance cannot be obtained. Therefore, a method of arranging a plurality of brightness enhancement films on a surface light source has also been proposed (see, for example, Patent Document 1). However, the brightness enhancement film is not necessarily advantageous from the viewpoint of productivity and thinning because it leads to an increase in cost and the number of films to be used increases.

  Furthermore, there is a problem that the weight of the light guide plate increases as the display becomes larger.

  As described above, it has been difficult for the edge light system to meet market demands such as an increase in display size and brightness in recent years.

  Therefore, a direct method using a plurality of light sources is attracting attention. FIG. 1 shows an example of this type of illumination system. In this example, the illuminating device has a rectangular emission surface having a width direction and a height direction perpendicular to the width direction, a plurality of linear light sources 1, a diffusion means 2 (light diffusion plate), and a reflection plate 6. The linear light source 1 is disposed in one imaginary plane parallel to the width direction and the height direction, and the linear light source 1 is disposed such that the longitudinal direction thereof is parallel to the width direction. And the diffusing means 2 (light diffusing plate) are arranged on the emission surface side of the arranged linear light sources 1 and the main surface is a linear light source. 1 is parallel to the virtual plane on which the array is arranged, and the reflector 4 is located on the opposite side of the diffuser 2 (light diffuser) across the arrayed linear light sources 1 and the reflector The main surface 6 is parallel to the virtual plane on which the linear light sources 1 are arranged. Further, in the diffusing means 2 (light diffusing plate), the light diffusing agent is usually uniformly dispersed and has a uniform optical performance in the main surface.

  The exit surface on the rectangle is most common in many applications of the present illumination device such as an image cover device or an illumination sign.

  Also, the linear light source is the most common light source for these illumination devices because it can easily eliminate unevenness of brightness and the wiring is short and easy compared to the point light source. A cold cathode tube or the like is often used as the linear light source. In general, it is advantageous for production to use the same type of linear light source, and it is also advantageous for uniform brightness. In this case, the linear light source is arranged in parallel to the width direction of the rectangular surface of the emission surface. It is preferable to reduce the number of linear light sources. In addition, luminance unevenness, which is a problem by arranging linear light sources at equal intervals in the same plane, becomes periodic with the arrangement of linear light sources, and a light diffusing plate having uniform optical performance in the main surface It is easy to eliminate luminance unevenness in The reflector is not essential, but it works to reflect the light emitted from the linear light source and the light diffusing plate opposite to the exit direction to the exit side and use it again as the exit light. It is advantageous.

  In addition, the direct method has a high utilization efficiency of the light emitted from the light source, that is, the ratio of the light flux emitted from the light exiting surface out of the light flux emitted from the light source, and can freely increase the light reduction number. The required high brightness can be easily obtained.

  Furthermore, since a light guide plate that directs light to the front is not necessary, the weight can be reduced.

  Further, as another lighting device, for example, an illumination signboard or the like has a simple structure, and a high brightness can be easily obtained without using a brightness enhancement film.

  However, the direct system has to solve unique problems such as elimination of lamp image, thinning, and energy saving. In particular, in applications where an illumination surface such as an image display device or an illumination signboard is observed, not only the elimination of the lamp image but also the in-plane luminance uniformity is required. Furthermore, in applications where the illumination surface is observed mainly from the front, such as a television or a personal computer monitor, the uniformity of the front luminance within the surface is the most important. Since the lamp image appears as significantly more uneven brightness than the edge light method, it is difficult to eliminate the problem by means such as a diffusion film in which a light diffusing agent is applied to the film surface that has been used in the conventional edge light method. Therefore, a light diffusing plate in which a light diffusing agent is dispersed in a base resin such as a methacrylic resin, a polycarbonate resin, a styrene resin, or a vinyl chloride resin is widely used. An example of a direct display device using a light diffusing plate is as already described with reference to FIG. However, methods using these light diffusing agents are not preferable from the viewpoint of energy saving because they absorb light into the light diffusing agent and diffuse light in unnecessary directions. Moreover, although a lamp image can be reduced by arranging a large number of light sources close to each other, there is a problem that power consumption increases.

  On the other hand, a method of erasing the lamp image by giving the reflector a unique shape has been proposed (see, for example, Patent Document 3). However, it is not preferable because it is necessary to align the shape of the reflector and the light source, and the thickness of the reflector may be hindered due to the shape of the reflector.

Furthermore, a method of arranging a reflective member facing the light source (for example, see Patent Document 4), a method of arranging a light beam direction conversion element such as a Fresnel lens for each light source, etc. (for example, see Patent Document 5) are also proposed. However, similarly, since the exact alignment of a member and a light source is required, the subject that productivity is inferior arises.

  Moreover, a light diffusing plate having irregularities on the surface has been proposed (see, for example, Patent Document 6). These diffusing plates can obtain desired diffusibility while avoiding or reducing the use of a diffusing agent, so that the light utilization efficiency can be enhanced. However, since there is no detailed examination on the uneven shape, it is difficult to strictly adjust the luminance unevenness. Similarly, it is difficult to obtain the uniformity of the front luminance within the exit surface.

  In addition, a prism sheet with little light loss has been proposed (see, for example, Patent Document 7). This forms a large number of convex portions on both sides of the sheet, each having a triangular or corrugated cross section and continuously extending in one direction. However, these prism sheets aim to reduce the light loss by directing the diffused light to the front, so it is not possible to eliminate the lamp image generated by the direct method.

  In a large illuminating device, since the demand for thinning is not strict as compared with a mobile phone or a mobile personal computer, it can be dealt with by shortening the distance between the light source and the light diffusion plate or reducing the number of optical films. In addition, in order to realize energy saving, it is necessary to increase the utilization efficiency of light. As described above, the direct method can increase the number of linear light sources, and it is easy to obtain high luminance. However, from the viewpoint of energy saving, a large amount of light diffusing agent is used to eliminate the lamp image. It must be suppressed to reduce the use efficiency.

See JP-A-2-17 See JP-A-54-155244 See Japanese Patent No. 2852424 See JP 2000-338895 A See JP 2002-352611 A See JP-A-10-123307 See Japanese Patent No. 3455844

  Therefore, in the present invention, high brightness, particularly high front brightness, wide viewing angle, high light utilization efficiency, easy response to the increase in size of the apparatus, and the front without exact alignment between the light source and other members. An object of the present invention is to provide an illuminating device in which uneven luminance in a direction is eliminated and which is advantageous for productivity and thinning, and an image display device using the same.

  Therefore, the present inventors solve the above-mentioned problem by arranging the first light beam control means and the second light beam direction control means that we propose in a general direct lighting system as illustrated in FIG. I found out. In response to the above problem, in the present invention, the first light beam control means narrows the viewing angle in the width direction and concentrates the front energy in the front direction, and the second light beam arranged on the emission surface of the first light beam control means. At the same time as increasing the viewing angle in the height direction by the control means and concentrating the front energy in the front direction, and at the same time increasing the use efficiency of light by appropriately widening the viewing angle in the width direction narrowed by the first light control means. Thus, it is possible to achieve high brightness and wide viewing angle, and particularly to improve frontal brightness suitable for many applications.

Then, the second light beam direction control means has a plurality of bowl-shaped convex portions, and by optimizing the cross-sectional shape thereof, the incident light is incident at all points on the surface where light enters the second light beam direction control means. It is possible to provide a uniform property that similarly controls the light exit direction, which is not only advantageous for size change, but also does not require alignment with the light source. Further, by making the light intensity distribution in the front direction constant, luminance unevenness in the front direction can be eliminated. Furthermore, the combined functions of the second light direction control means, such as elimination of luminance unevenness and improvement of luminance, can eliminate or reduce the use of other functional optical films, which is advantageous for productivity and thinning. Furthermore, it is also possible to increase the front intensity by increasing the light emission ratio in the front direction of the second light direction control means. In addition, an image display device can be obtained by disposing a transmissive display element on the outgoing light side of these illumination devices.
Here, “a plurality of ridge-shaped convex portions” indicates a convex portion that has a curved or polygonal cross section (excluding triangles) and extends in one direction, and the cross section has two straight lines excluding the main surface. The so-called “prism” composed of is not included.

  An illumination device provided by the present invention is a substantially rectangular parallelepiped illumination device having a width, a height, and a thickness that intersect perpendicularly to each other, and the illumination device includes a plurality of linear light sources and first light direction control means. And a second light direction control means, wherein the first light direction control means is a member for narrowing the viewing angle characteristic in the width direction, and the second light direction control means has a viewing angle characteristic in the width direction. It is a member for spreading appropriately and eliminating uneven brightness.

  If the distribution of the outgoing light intensity is almost constant, the luminance unevenness is eliminated and the luminance uniformity is obtained. In the illuminating device in which the linear light sources are arranged as described above, the distribution of the light output intensity is the sum of the light output intensity distributions of the respective linear light sources. It will be resolved.

  The illuminating device of the present invention eliminates uneven brightness in the front direction by making the light intensity distribution in the front direction substantially constant. In addition, an image display device can be obtained by disposing a transmissive display element on the emission side of these illumination devices. Here, the front direction means a minute solid angle centered on the normal direction of the main surface of the second light direction control means.

Hereinafter, the means provided by the present invention will be described in detail.
The present invention
A substantially rectangular parallelepiped lighting device having a width, a height, and a thickness perpendicular to each other,
The width, height and thickness values are larger in this order,
To the thickness direction emission side, linear light source, first light direction control means, second light direction control means, in this order,
A plurality of the linear light sources are arranged in parallel over the entire area,
Each of the first light direction control means and the second light direction control means is a plurality of bowl-shaped protrusions,
The first light direction control means controls the light direction along the width direction of the light from the linear light source and directs it to the second light direction control means.
The second light direction control means controls the light direction along the height direction of the light from the first light direction control means,
And it is an illuminating device characterized by returning a part of light toward the first light beam direction control means.

  Moreover, this invention WHEREIN: You may have a spreading | diffusion means between said linear light source and said 1st light direction control means in said illuminating device.

  In the illumination device according to the present invention, the first light beam direction control unit and the second light beam direction control unit may have substantially the same cross-sectional shape perpendicular to the longitudinal direction of the hook-shaped projections.

  Furthermore, in the illumination device according to the aspect of the invention, the diffusing unit may be provided on a sheet-like member that is integral with the first light direction control unit, or the diffusing unit may be the first light direction control unit. May be provided on different sheet-like members.

  Further, in the illumination device according to the present invention, the diffusing unit may be fine particles dispersed in and / or on the surface of the sheet-like member, or the diffusing unit may be finely provided on the surface of the sheet-like member. An uneven shape may be used.

  In the illumination device according to the present invention, the plurality of linear light sources are arranged so as to be parallel to the width direction of the illumination device and over substantially the entire width direction, and are arranged along the height direction. Also good.

  Furthermore, the present invention is an image display device characterized in that a transmissive display element is provided on the surface on which the second light beam direction control means is provided so as to cover the illumination device.

Next, the effects of the means provided by the present invention will be described in detail.
The present invention, in the direct system, has high light utilization efficiency, wide viewing angle, and constant light output intensity distribution in the front direction, so that there is no uneven brightness in the front direction such as a lamp image and the front direction. Provided is a lighting device with high brightness. Furthermore, since it is possible to perform the same optical control at all places on the light incident on the first light direction control means, the second light direction control means and the reflector, the linear light source and other light sources Provided is a lighting device that does not require alignment with a member, can respond immediately to changes in the display size and the number and arrangement of linear light sources, and can be manufactured with high productivity. Moreover, the image display apparatus using the illuminating device which has a 1st light direction control means and a 2nd light direction control means is provided.

  The effects of the present invention are as follows. Since the width, height, and thickness values increase in this order and the width and height directions become the illumination surface, the display is thin and has a large screen, and the width direction is arranged horizontally, which is suitable for many display devices. The first light direction control means can control the light direction along the width direction to obtain high front luminance and obtain a preferable horizontal viewing angle. The second light direction control means can obtain a preferable vertical viewing angle by controlling the light direction along the height direction. Further, the second light direction control means improves the diffusibility in the horizontal direction by returning a part of the light to the first light direction control means, thereby eliminating unevenness in brightness desirable in many applications and obtaining brightness uniformity.

  Further, by using a diffusing unit between the linear light source and the first light beam direction control unit, it becomes easier to erase the image of the linear light source.

  Moreover, it becomes advantageous on manufacture because the cross-sectional shape of the hook-shaped convex part which comprises a 1st light direction control means and a 2nd light direction control means is mutually the same.

  Alternatively, since the diffusing unit is provided on a sheet-like member that is integral with the first light beam direction controlling unit, the number of members can be reduced, which is advantageous for thinning.

  Further, since the first light beam direction control means can be made thin by making the diffusing means as a support, it is possible to reduce changes in optical characteristics caused by warping, which is advantageous in manufacturing the first light beam direction control means. It is. Alternatively, when the diffusing means is a sheet-like member, mechanical strength can be ensured, and light diffusibility can be easily controlled by adjusting the concentration, size, refractive index, etc. of the fine particles, and uneven brightness in the front direction can be achieved. It is advantageous in eliminating it.

  Furthermore, manufacture becomes easy by making the said spreading | diffusion means into the fine uneven | corrugated shape provided in the surface of the sheet-like member.

  In addition, it is advantageous in production to use the same type of linear light source, and it is also advantageous for uniforming the luminance. In this case, the linear light source is arranged in parallel with the width direction of the rectangle of the emission surface. This is preferable because the number of linear light sources can be reduced. Further, by arranging the linear light sources at equal intervals in the same plane, the luminance unevenness which is the subject of the present invention becomes periodic due to the arrangement of the linear light sources, and uniform optical performance in the main surface. It is easy to eliminate luminance unevenness by the light beam direction control means. Further, by arranging the linear light source in parallel with the width direction, the number of parts can be reduced as compared with the arrangement in the height direction.

  The lighting device is a lighting device with high front luminance and uniform luminance distribution in the front direction. By providing a transmissive display element on the emission side of the lighting device, the lighting device can be used as a preferable image display device. Here, the image display device refers to a display module in which an illumination device and a display device are combined, and a device having at least an image display function such as a television or a personal computer monitor using the display module.

It is the schematic of the conventional illuminating device of a direct system. It is the schematic of the suitable example of the illuminating device of this invention, and the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on Example 2 and Example 4. FIG. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on Example 1 and Example 3. FIG. FIG. 10 is a configuration diagram of a backlight device for a liquid crystal display device according to Embodiment 5 as viewed from obliquely above. FIG. 10 is a configuration diagram of a backlight device for a liquid crystal display device according to Example 6 as viewed from obliquely above. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on the comparative example 1. FIG. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on the comparative example 2. FIG. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on the comparative example 3. FIG. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on the comparative example 4. FIG. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on the comparative example 5. FIG. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on the comparative example 6. FIG. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on the comparative example 7. FIG. It is the block diagram seen from diagonally upward of the backlight apparatus for liquid crystal display devices which concerns on the comparative example 8. FIG.

Explanation of symbols

1 linear light source 2 diffusion means (light diffusion plate)
3 First light direction control means 4 Second light direction control means 5 Diffusion means (light diffusion sheet)
6 reflector

  FIG. 2 shows an example of an embodiment of a lighting device provided by the present invention. An illumination device having a rectangular emission surface composed of a width direction and a height direction perpendicular thereto, wherein the linear light source 1 has a height in one virtual plane parallel to the width direction and the height direction. It is arranged in parallel with the direction and along the width direction. The first light direction control means 3 is provided with first light direction control means 3 in a single virtual plane parallel to the width direction and the height direction, parallel to the height direction, from the linear light source 1 to the exit surface. The light beam direction control member and the second light beam direction control member including the second light beam direction control means 4 are arranged in this order. The diffusing means 2 in FIG. 2 is not necessarily essential in the present invention, but is preferably used because it has an effect of easily erasing the image of the linear light source. Naturally, the diffusion means 2 is not limited to the light diffusion plate as shown in FIG.

  As a suitable example of the first light beam direction control means 3, a plurality of small bowl-like shapes arranged in parallel in the height direction on at least one of the principal surfaces of the plate-like member provided with the principal surface perpendicular to the thickness direction. The convex part is mentioned.

  As a preferred example of the second light beam direction control means 4, a plurality of small ridges arranged in parallel in the width direction on at least one of the main surfaces of the plate-like member provided with the main surface perpendicular to the thickness direction. Shaped protrusions.

  Hereinafter, a preferred embodiment in which the light beam direction control means is constituted by a convex portion provided on the main surface of the plate-like member will be described in more detail.

  The light beam direction control means can be provided on the incident surface located on the linear light source side of the illumination device and / or the exit surface located on the light exit surface side.

  The cross-sectional shape of the convex portion can be selected from polygons (excluding triangles), curved lines, and combinations of these. When the polygon has a relatively large number of corners, it can be dispersed while controlling the light emission direction, so that highly uniform light emission can be obtained. Moreover, since the angle of an adjacent side can be taken comparatively widely, it is hard to damage and is preferable. When it is a curved surface, it is more preferable from the viewpoints of the uniformity and resistance to breakage. There are no particular restrictions on the preferred curved surface shape, but examples include a substantially semicircular shape, an elliptical shape, a parabolic shape, and a shape that does not substantially have an inflection point, and a wave shape that gently curves near the valley. . When the number of inflection points is small, the direction of the light beam can be easily controlled, and irregular reflection is less likely to occur. Conversely, in order to increase the diffusibility, a plurality of inflection points can be provided.

  Moreover, although the said convex part is arranged continuously, you may provide a flat part between convex parts. Providing the flat portion is advantageous because the convex portion of the mold is difficult to deform. Further, since the light directly above the linear light source is emitted in the front direction, it is advantageous when only the luminance immediately above the linear light source is increased. On the contrary, in the case of a shape having no flat part, all light can be controlled by the inclination of the slope of the convex part, so that the light intensity distribution in the front direction becomes uniform.

  The light exit direction distribution is determined by the slope angle distribution of the convex portion. Therefore, by adjusting the slope angle distribution, for example, the front luminance can be made uniform in the plane, so that a suitable surface light source is obtained. Further, since the second light beam direction control unit controls the light beam direction in the height direction, it is possible to alleviate luminance unevenness of the linear light source arranged in parallel with the width direction. The second light direction control means reflects straight light from the linear light source causing the lamp image, that is, light incident on the second light direction control means at a small incident angle, and the second light direction control means. Luminance unevenness is mitigated by transmitting light incident at a large incident angle. The second light beam direction control means can determine the ratio of reflection to the first light beam direction control means by the slope angle distribution. The light reflected by the second light direction control member impinges on the first light direction control member to be transmitted and reflected, thereby increasing diffusibility, further reducing luminance unevenness, and improving luminance uniformity in the width direction.

Although there is no limitation on the method for shaping the convex shape is the first light beam direction control means and / or the second light beam direction control means, extrusion molding, injection molding, 2P molding using an ultraviolet curable resin (P hoto P olymerization Process) and the like. The molding method may be appropriately used in consideration of the size of the projection, the required shape, and mass productivity. When the main surface size is large, extrusion molding is suitable.

  Moreover, it is preferable that the convex part which is a 1st light direction control means and / or a 2nd light direction control means has the same cross-sectional shape. Since the optical properties of the second light direction control means are uniform, alignment is not required, and it is possible to respond immediately to changes in the display size and the number and arrangement of linear light sources, and to produce a lighting device with high productivity be able to.

  Further, when the first light direction control means and / or the second light direction control means is a hook-shaped convex portion, the first light direction control means and the second light direction control means are materials used as a base material of the optical member. Can be preferably used, and usually a light-transmitting thermoplastic resin is used. For example, (meth) acrylic resin, (meth) acryl styrene copolymer resin, styrene resin, aromatic vinyl resin, olefin resin, ethylene vinyl acetate copolymer resin, vinyl chloride resin, vinyl ester resin , Polycarbonate, fluorine resin, urethane resin, silicone resin, amide resin, imide resin, polyester resin, epoxy resin, phenol resin, urea resin, melamine resin, and the like. Moreover, it is also possible to perform 2P molding of the first light direction control means or the second light direction control means with a UV curable resin on a film or sheet as a substrate.

  The first light direction control means and / or the second light direction control means of the present invention can be made using a plurality of different materials as required. For example, the first light direction control means and / or the second light direction control means is formed with a ridge-shaped convex portion on the film, and then the support plate is aligned with the film surface on which the convex portion is not formed, and the light direction control member It can also be. For example, when an ultraviolet curable resin is used for forming the convex portion, the amount of the expensive ultraviolet curable resin used can be reduced by using a general-purpose translucent resin other than the vicinity of the convex portion.

  When the light diffusing means is in a plate-like member and the first light beam direction control means and the second light beam direction control means are plate-like structures, these may be the same plate.

  When using a support plate, it is arranged on the base part of the first light direction control means and / or the second light direction control means or on the linear light source side of the first light direction control means and / or the second light direction control means. The member to be formed may be a plurality of types of plates having different refractive indexes.

Further, by providing the light diffusing means for the first light direction control means and / or the second light direction control means of the present invention, it is possible to further improve the luminance uniformity.
As the light diffusing means, a method of providing random unevenness such as embossing or embossing on the main surface of the plate member, a method of dispersing a small amount of light diffusing agent inside the structure, a diffusion sheet on the incident side of the light control member and Examples thereof include a method provided on the emission side, or a method combining these.

  Random irregularities can be formed by applying a solution in which fine particles are dispersed to the main surface or by transferring from a mold having irregularities. These can be provided on the light source side and / or the emission surface side of the light control member. As for the degree of unevenness, the arithmetic average roughness Ra is preferably 3 μm or less. If it becomes larger than this, the diffusion effect becomes too large, and the front luminance is lowered. When the incident surface is flat, light incident from various directions is condensed near the front to some extent due to refraction at the incident surface when entering the light control member. Will increase. For example, when the refractive index of the light control member is 1.55, the light is condensed in an angle range within 40 degrees with respect to the normal direction of the incident surface. When unevenness is given to the incident surface, the light incident on the light control member is refracted at a wide angle and proceeds, so that the effect of increasing the light emission ratio in the front direction may be reduced. Moreover, when providing a fine unevenness | corrugation in an output surface, the effect which increases the light emission ratio to a front direction similarly by an unevenness | corrugation may be reduced by being refracted by an uneven surface. It can adjust to the range preferable for the use used from the balance of the diffusibility obtained, the brightness nonuniformity elimination effect, and front brightness.

  When applying the light diffusing agent, it is more preferable to apply it on the light exit surface side. As the light diffusing agent, inorganic fine particles and crosslinked organic fine particles used in conventional light diffusing plates and diffusion sheets can be used. The amount used is extremely small compared to the conventional general light diffusion plate, and the same or better diffusibility can be obtained, and the transmittance is very high.

  As for the height of the hook-shaped convex part of a 1st light direction control means and a 2nd light direction control means, 1 micrometer-500 micrometers are desirable. When the thickness is larger than 500 μm, when the exit surface is observed, the ridge-shaped convex portion is easily confirmed, resulting in deterioration of the quality. On the other hand, when the thickness is smaller than 1 μm, coloring occurs due to the diffraction phenomenon of light, and the quality deteriorates.

  Furthermore, in the image display device of the present invention in which the transmissive liquid crystal panel is provided as the transmissive display element, the width of the ridge-shaped convex portion in the height direction in the second light direction control means is the pixel pitch of the liquid crystal in the height direction. It is preferable that it is 1/100-1 / 1.5. If it is larger than this, moire occurs due to the relationship between the second light beam direction control member and the liquid crystal panel, and the image quality is greatly reduced.

By providing the diffusing unit between the linear light source and the first light direction control unit, it is possible to further improve the uniformity of luminance.
As the light diffusing means, a method of providing random unevenness such as embossing or embossing on the main surface of the plate member, a method of dispersing a light diffusing agent inside the structure, a diffusion sheet on the incident side of the light control member and / or A method of providing on the emission side, or a method of combining them is mentioned. Random irregularities can be formed by applying a solution in which fine particles are dispersed to the main surface or by transferring from a mold having irregularities. These can be provided on the light source side and / or the emission surface side of the light control member. As for the degree of unevenness, the arithmetic average roughness Ra is preferably 3 μm or less. If it becomes larger than this, the diffusion effect becomes too large, and the front luminance is lowered. When the incident surface is flat, light incident from various directions is condensed near the front to some extent due to refraction at the incident surface when entering the light control member. Will increase. For example, when the refractive index of the light control member is 1.55, the light is condensed in an angle range within 40 degrees with respect to the normal direction of the incident surface. When unevenness is given to the incident surface, the light incident on the light control member is refracted at a wide angle and proceeds, so that the effect of increasing the light emission ratio in the front direction may be reduced. Moreover, when providing a fine unevenness | corrugation in an output surface, the effect which increases the light emission ratio to a front direction similarly by an unevenness | corrugation may be reduced by being refracted by an uneven surface. It can adjust to the range preferable for the use used from the balance of the diffusibility obtained, the brightness nonuniformity elimination effect, and front brightness.

  For the diffusing means, a material usually used as a base material of an optical member can be preferably used, and usually a light-transmitting thermoplastic resin is used. For example, meth) acrylic resin, (meth) acryl styrene copolymer resin, styrene resin, aromatic vinyl resin, olefin resin, ethylene vinyl acetate copolymer resin, vinyl chloride resin, vinyl ester resin, polycarbonate , Fluorine resin, urethane resin, silicone resin, amide resin, imide resin, polyester resin, epoxy resin, phenol resin, urea resin, melamine resin, and the like.

  When the light diffusing agent is dispersed in the structure as the diffusing means, there is no particular limitation, but the light diffusing agent is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the transparent resin. More preferably, it can be contained in an amount of 0.1 to 15 parts by mass, more preferably 0.3 to 10 parts by mass, and the content is less than 0.01 parts by mass with respect to 100 parts by mass of the transparent resin. In addition, the light diffusibility is not sufficient, and if it exceeds 20 parts by mass, a sufficient total light transmittance cannot be obtained, and the strength may not be sufficient.

  The average particle size of the light diffusing agent is preferably in the range of 1 to 30 μm, and more preferably in the range of 2 to 20 μm. When the average particle diameter of the light diffusing agent is smaller than 1 μm, the light diffusing resin composition obtained by dispersing the light diffusing agent in the transparent resin selectively scatters light having a short wavelength, so that transmitted light does not transmit. It is yellowish and is not preferred. On the other hand, when the average particle diameter of the light diffusing agent exceeds 30 μm, the light diffusing resin composition obtained by dispersing in the transparent resin has a reduced light diffusibility or light when the light is transmitted through the resin. The diffusing agent may be easily seen as a foreign substance, which is not preferable. The shape of the light diffusing agent is preferably an oval or spherical shape, more preferably a spherical shape.

  As the light diffusing agent, usually, inorganic and / or organic transparent fine particles having a refractive index different from that of the transparent resin of the base material are used. Regarding the difference between the refractive index of the light diffusing agent and the refractive index of the substrate, the absolute value is preferably 0.02 or more from the viewpoint of light diffusibility, and light is preferably 0.15 or less. It is preferable from the viewpoint of permeability. In the present invention, by providing the difference in refractive index between the light diffusing agent and the base material as described above, so-called internal diffusibility can be imparted, but the light diffusing agent is raised on the surface of the base material. By forming surface irregularities, so-called external diffusibility can be imparted.

  Examples of the inorganic light diffusing agent include calcium carbonate, barium sulfate, titanium oxide, aluminum hydroxide, silica, glass, talc, mica, white carbon, magnesium oxide, and zinc oxide. The surface treatment may be performed. Examples of the organic light diffusing agent include styrene polymer particles, acrylic polymer particles, siloxane polymer particles, fluorine polymer particles, and the like. A high heat-resistant light diffusing agent having a temperature of 250 ° C. or higher or a crosslinked polymer particle having a gel fraction of 10% or higher when dissolved in acetone is suitably used. Of these light diffusing agents, silica, glass, acrylic polymer particles, and siloxane polymer particles are preferably used, and acrylic polymer particles and siloxane polymer particles are more preferably used. Further, these light diffusing agents can be used in two or more kinds as required.

  Either the first light direction control means, the second light direction control means or the diffusion means is preferably a plate-like member, and the member disposed on the linear light source side is more preferably a plate-like member. . Since the member on the side of the linear light source is a plate-like member, the mechanical strength is increased, and deterioration of optical characteristics due to warpage or the like can be prevented.

  When the diffusing means provided between the linear light source of the present invention and the first light direction control means is provided on a plate member, the thickness of the plate member is preferably 0.8 to 10 mm, more preferably Is 1-5 mm. Thinner sheets can be brighter, lighter, and more economical, but if the thickness is less than 0.8 mm, the mechanical strength of the light diffusing plate becomes insufficient, causing problems such as deflection. May be difficult.

  By disposing the reflecting plate 6 on the side opposite to the emission side (back side) of the linear light source, light reflected from the linear light source 1 toward the back side or reflected by the first light direction control means or the second light direction control means. Then, since the light traveling toward the back surface is further reflected to the exit side, the light utilization efficiency is increased because the light can be used effectively.

  It is desirable that the reflectance of the reflecting plate 6 disposed on the back surface in parallel with the width direction and the height direction is 95% or more. Light utilization efficiency because light traveling from the linear light source 1 to the back surface, or light reflected by the diffusing unit 2 or the first light beam direction control unit 3 and reflected toward the back surface is further reflected to the emission side. Becomes higher. Examples of the material of the reflector include metal foils such as aluminum, silver, and stainless steel, white coating, and foamed PET resin. A reflector having a high reflectivity is preferable for improving the light utilization efficiency. From this viewpoint, silver, foamed PET resin and the like are preferable. Further, a material that diffuses and reflects light is preferable in terms of improving the uniformity of the emitted light. From this viewpoint, foamed PET resin and the like are preferable.

  You may provide the light-diffusion sheet which has a light-diffusion function in the incident surface side and / or output surface side of a 1st light beam direction control means, and the incident surface side and / or output surface side of a 2nd light beam means. A more uniform front luminance distribution can be obtained by diffusion using the light diffusion sheet.

  The image display device of the present invention is realized by a method such as using a transmissive liquid crystal display element on a lighting device, and is not particularly limited, but the transmissive display device includes a transmissive liquid crystal panel, An image display device having excellent display surface luminance uniformity can be obtained.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

The structure of the extrusion apparatus used for production of various plate-like members used in the present invention is as follows.
Extruder: Screw diameter 65 mm (L / D = 28), single screw, with vent (SE65CVA; Toshiba Machine Co., Ltd.).
Die: T die, lip width 1000 mm, lip interval 5 mm.
Roll: 3 polishing rolls, vertical type.

(Diffusion means: preparation of light diffusion plate)
The light diffusing plate used as the diffusing means between the linear light source and the first light beam direction control means was produced as follows.
(1) Methacrylstyrene-based copolymer resin pellets (TX-800S: manufactured by Denki Kagaku Kogyo Co., Ltd., refractive index 1.549)) and siloxane polymer particles (Tospearl 120: manufactured by GE Toshiba Silicone Co., Ltd., refractive index) : 1.420) 1.0 mass% and 2- (5-methyl-2-hydroxyphenyl) benzotriazole 0.1 mass% which is an ultraviolet absorber are mixed with a Henschel mixer, and then melt-kneaded using an extruder. A light diffusion plate (P-1) having a width of 1000 mm and a thickness of 2 mm was obtained at an extrusion resin temperature of 235 ° C.

(2) Methacryl styrene copolymer resin pellets (TX-800S: manufactured by Denki Kagaku Kogyo Co., Ltd., refractive index 1.549)) and siloxane polymer particles (Tospearl 120: manufactured by GE Toshiba Silicone Co., Ltd., refractive index: 1.420) 0.4% by mass and UV absorber 2- (5-methyl-2-hydroxyphenyl) benzotriazole 0.1% by mass are mixed with a Henschel mixer, melt-kneaded using an extruder, and extruded. A light diffusion plate (P-2) having a width of 1000 mm and a thickness of 2 mm was obtained at a resin temperature of 235 ° C.

(3) Methacryl styrene copolymer resin pellets (TX-800S: manufactured by Denki Kagaku Kogyo Co., Ltd., refractive index 1.549)) and siloxane polymer particles (Tospearl 120: manufactured by GE Toshiba Silicone Co., Ltd., refractive index: 1.420) 3.0% by mass and ultraviolet absorber 2- (5-methyl-2-hydroxyphenyl) benzotriazole 0.1% by mass are mixed with a Henschel mixer, melt-kneaded using an extruder, and extruded. A light diffusion plate (P-3) having a width of 1000 mm and a thickness of 2 mm was obtained at a resin temperature of 235 ° C.

(Production of light direction control means)
A member having a light beam direction control means characterized in that a flat surface is formed on the light incident surface and an elliptical shape is formed on the light output surface was manufactured as follows.
First, the female metal mold | die which has a groove | channel of the elliptical arc-shaped cross section of unit convex part width P1 = 80micrometer was produced by cutting.

First, the cross-sectional shape of the unit convex portion is ^{y = 0.139-8.33x 2 /(1+(1-38.9x 2) 1/2} ) (- 0.4 ≦ x ≦ 0.4 (mm))
A female die having a cylindrical groove represented by the following formula was produced by cutting. Here, x is a coordinate orthogonal to the linear light source, and y is a height from the bottom of the convex portion. The lens shape was symmetrical with respect to the mold surface, and the depth was constant in the plane. Next, from the mold, a lens shape is formed on the surface of a polycarbonate film having a thickness of 0.4 mm with an ultraviolet curable resin to obtain a member (B-1) having a light beam direction control means on which a convex lens is formed. It was.

(2) Light diffusion obtained by the above-described extrusion molding on the surface of the member (B-1) having the light beam direction control means on which the convex lens obtained by the above-described production method is formed. The member (B-2) which has the light beam direction control means in which the convex-shaped lens was formed was bonded together on the single side | surface of a board (P-2).

(1) Measurement of luminance and half-value angle The luminance and viewing angle of the molded specimen were measured by the following arrangement and method using the following illumination device.
Illumination device: A backlight device of a commercially available liquid crystal television set (27 “WLCD-TV N3272 manufactured by Polyvision) was used. Measurement arrangement: Each member described in Examples and Comparative Examples described later is arranged in the illumination device and rotated. A luminance meter (BM-5A; manufactured by Topcon Co., Ltd.) was fixed at a position 500 mm away from the outermost surface (outgoing light side) of the member placed on the stage and further disposed on the stage.
Measurement method: A line connecting the center point of the illuminating device and the luminance meter was used as a center line, the exit surface of the illuminating device was fixed in a direction perpendicular to the center line, and the angle was set to 0 degree. The brightness in this state was measured and used as the center brightness. Next, the luminance value of the illuminating device was measured at intervals of 1 degree while rotating the rotary stage in the width direction of the illuminating device. Then, when the luminance value obtained at each measurement angle when the half-value angle (width direction) is rotationally scanned in the width direction is divided by the luminance value obtained at an angle of 0 degrees, the measurement angle when 1/2 is obtained. As sought.
Moreover, the luminance value of the illuminating device was measured at intervals of 1 degree while rotating the rotary stage in the height direction of the illuminating device in the same manner as described above. The half-value angle (height direction) is 1/2 when the luminance value obtained at each measurement angle when rotated and scanned in the width direction is divided by the luminance value obtained at an angle of 0 degrees. Obtained as a measurement angle.

(2) Evaluation of brightness At the time of measuring the brightness, the brightness value at an angle of 0 degree on the outermost surface (outgoing light side) of the member arranged in the illumination device is used, and the symbols ○, Δ, and X are as follows: evaluated.
A: 10500 cd / m ² or more
△: 10000 cd / ^{m 2} or more 10500Cd / what ^m is less than ² ×: ^10000cd / ^{m 2} less than a is one

(3) Evaluation of viewing angle Using the half-value angle of the outermost surface (outgoing light side) of the member arranged in the illuminating device, evaluation was performed with symbols ◯ and X as follows.
○: Half-value angle (width direction) ≧ 40 ° and half-value angle (height direction) ≧ 35 °
: Wide viewing angle with no problems in actual use.
×: Half-value angle (width direction) <40 ° and / or Half-value angle (height direction) ≧ 35 °
: The viewing angle is narrow and poor.

(4) Disappearance condition of light source image When measuring the above brightness, visually observe the disappearance condition of the light source image by visually observing the outermost surface (outgoing light side) of the member arranged in the illuminating device. , X.
○: Light source image disappeared △: Light source image was blurred ×: Light source shape was clearly recognizable

(Configuration of the backlight device used)
As a lighting device of this example and a comparative example, a backlight device of a commercially available liquid crystal television set (27 inch wide LCD-TV N3272 manufactured by Polyvision) was used. That is, as the light source C and the reflection plate D, those provided in the backlight device were used as they were.
The configuration of the lighting device is shown in the schematic diagram of FIG. Details of the lighting device not shown are described below. The length in the width direction was 620 mm, the length in the height direction was 355 mm, and the length in the thickness direction perpendicular to the width direction and the height direction was 18 mm. A white reflecting plate 6 was provided so as to cover the bottom portion at a position facing the opening on the emission side of the backlight device.
The linear light source 1 is arranged in parallel with the reflecting plate with an interval of 2.5 mm on the emission side of the reflecting plate 6. As the linear light source 1, sixteen cold cathode tubes having a diameter of 3 mm and a length of 625 mm were arranged with the longitudinal direction parallel to the height direction and spaced by 24 mm along the width direction.

Example 1
First, the diffusing means 2 (light diffusing plate) (P-1) obtained above is arranged on the light exit surface side of the backlight, and the diffusing means 5 (light diffusing sheet; The product name “Opulse” BS-042) manufactured by Wa Corporation was superposed.
Next, as shown in FIG. 3, the first light direction control means 3 was disposed thereon. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the diffusing means 5 (light diffusing sheet) in a direction substantially orthogonal to each other.
Further, as shown in FIG. 3, the second light direction control means 4 is disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube which is the linear light source 1 and the convex lens ridge line are installed on the first light beam direction control means 3 in a direction substantially parallel to each other.
The evaluation results are shown in Table 1. A first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and a second light beam arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other. When combined with a direction control member and combined with a light diffusing plate (P-1) having a diffusing means between the linear light source and the first light direction control means, the measured luminance is a high value and half value The corners were wide and the light source image disappeared.

(Example 2)
The diffusing means 2 (light diffusing plate) (P-1) obtained above was disposed on the light exit surface side of the backlight.
Next, as shown in FIG. 2, the first light direction control means 3 was disposed thereon. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the diffusing means 2 (light diffusing plate) (P-1) in a direction substantially orthogonal to the convex shape.
Further, as shown in FIG. 2, the second light direction control means 4 is disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the first light beam direction control means 3 in a direction substantially parallel to each other.
The evaluation results are shown in Table 1. A first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and a second light beam arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other. When combined with a direction control member and combined with a light diffusing plate (P-1) having a diffusing means between the linear light source and the first light beam direction controlling means, the measured luminance is a high value and half value. The corners were wide and the light source image disappeared.

(Example 3)
First, the diffusing means 2 (light diffusing plate) (P-2) obtained above is arranged on the light emission surface side of the backlight, and the diffusing means 5 (light diffusing sheet; The product name “Opulse” BS-042) manufactured by Wa Corporation was superposed.
Next, as shown in FIG. 3, the first light direction control means 3 was disposed thereon. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion sheet 5 in a direction substantially orthogonal to each other.
Further, as shown in FIG. 3, the second light direction control means 4 is disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube which is the linear light source 1 and the convex lens ridge line are installed on the first light beam direction control means 3 in a direction substantially parallel to each other.
The evaluation results are shown in Table 1. A first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and a second light beam arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other. When combined with a direction control member, and combined with a light diffusing plate (P-2) having a diffusing means between the linear light source and the first light direction control means, the measured luminance is a high value and half value. The corners were wide and the light source image disappeared.

Example 4
The diffusing means 2 (light diffusing plate) (P-3) obtained above was arranged on the light exit surface side of the backlight.
Next, as shown in FIG. 2, the first light direction control means 3 was disposed thereon. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube as the linear light source 1 and the convex lens ridge line were installed on the light diffusing plate 2 (P-3) in a direction substantially perpendicular to each other.
Further, as shown in FIG. 2, the second light direction control means 4 is disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube which is the linear light source 1 and the convex lens ridge line are installed on the first light beam direction control means 3 in a direction substantially parallel to each other.
The evaluation results are shown in Table 1. A first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and a second light beam arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other. When combined with a direction control member and combined with a light diffusing plate (P-3) having a diffusing means between the linear light source and the first light beam direction controlling means, the measured luminance is a high value and half value. The corners were wide and the light source image disappeared.

(Example 5)
The diffusing means 2 (light diffusing plate) (P-1) obtained above was arranged on the light exit surface side of the backlight.
Next, as shown in FIG. 4, the first light direction control means 3 was disposed thereon. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube as the linear light source 1 and the convex lens ridge line are installed on the light diffusion plate 2 (P-1) in a direction substantially orthogonal to each other.
Furthermore, as shown in FIG. 4, the diffusion means 5 (light diffusion sheet; trade name “Opulse” BS-042 manufactured by Keiwa Co., Ltd.) was superimposed thereon.
Furthermore, as shown in FIG. 4, the second light direction control means 4 is disposed thereon. As the second light direction control means 4, a member (P-1) having a light direction control means on which a convex lens is formed is oriented so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion sheet 5 in a direction that is substantially parallel.
The evaluation results are shown in Table 1. A first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and a second light beam arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other. When combined with a direction control means, and combined with a light diffusing plate (P-3) having a diffusing means between the linear light source and the first light direction control means, the measured luminance is a value sufficient for an illuminating device. The half-value angle was wide and the light source image disappeared.

(Example 6)
The member (B-2) having the first light direction control means 3 obtained as described above was arranged on the emission surface side of the backlight. As the first light direction control means 3, a member (B-2) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube as the linear light source 1 and the convex lens ridge line were installed in a direction substantially orthogonal to each other.
Next, as shown in FIG. 5, the diffusion means 5 (light diffusion sheet; trade name “Opulse” BS-042 manufactured by Keiwa Co., Ltd.) was superimposed thereon.
Furthermore, as shown in FIG. 5, the second light direction control means 4 is disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion sheet 5 in a direction that is substantially parallel.
The evaluation results are shown in Table 1. A first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and a second light beam arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other. When combined with the direction control member, the measured luminance had a sufficient value as a lighting device, the half-value angle was wide, and the light source image disappeared.

(Comparative Example 1)
The diffusing means 2 (light diffusing plate) (P-1) obtained above is arranged on the light exit surface side of the backlight, and as shown in FIG. 6, the diffusing means 5 (light diffusing sheet; The product name “Opulse” BS-042) manufactured by the company was overlaid.
Next, as shown in FIG. 6, the first light direction control means 3 was disposed thereon. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion sheet 5 in a direction substantially orthogonal to each other.
The evaluation results are shown in Table 1. A light diffusing plate having first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and a diffusion means between the linear light source and the first light beam direction control means ( In combination with P-1), the half-value angle was narrow and the light source image was clearly visible, which was not preferable as a lighting device.

(Comparative Example 2)
The diffusing means 2 (light diffusing plate) (P-1) obtained above is arranged on the light exit surface side of the backlight, and as shown in FIG. 7, the diffusing means 5 (light diffusing sheet; The product name “Opulse” BS-042) manufactured by the company was overlaid.
Next, as shown in FIG. 7, the second light direction control means 4 was disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion sheet 5 in a direction that is substantially parallel.
The evaluation results are shown in Table 1. A light diffusing plate having a second light beam direction control means disposed in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially parallel, and a diffusing means between the linear light source and the second light beam direction control means In combination with (P-1), the measured luminance was lowered, which was not preferable as a lighting device.

(Comparative Example 3)
The diffusing means 2 (light diffusing plate) (P-1) obtained above is arranged on the light exit surface side of the backlight, and the diffusing means 5 (light diffusing sheet; The product name “Opulse” BS-042) manufactured by the company was overlaid.
Next, as shown in FIG. 8, the first light direction control means 3 was disposed thereon. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion sheet 5 in a direction substantially orthogonal to each other.
Furthermore, as shown in FIG. 8, the member which has the 1st light beam direction control means 3 of the 2nd sheet | seat was arrange | positioned on it. A convex lens is formed as the first light direction control means 3, and the member (B-1) having the light direction control means is oriented with the surface on which the convex lens is formed opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube as the linear light source 1 and the convex lens ridge line are installed on the first light beam direction control means 3 in a direction substantially orthogonal to each other.
The evaluation results are shown in Table 1. Two first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and the diffusion means between the linear light source and the first light beam direction control means When combined with a light diffusing plate (P-1) having, the measured luminance was lowered, the half-value angle was narrow, and the light source image was clearly visible, which was not preferable as a lighting device. Further, moire generated due to interference with the arrangement period of the convex portions of the two first light beam direction control means occurred.

(Comparative Example 4)
First, the diffusing means 2 (light diffusing plate) (P-1) obtained above is disposed on the light exit surface side of the backlight, and the diffusing means 5 (light diffusing sheet; The product name “Opulse” BS-042) manufactured by Wa Corporation was superposed.
Next, as shown in FIG. 9, the second light direction control means 4 was disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion sheet 5 in a direction that is substantially parallel.
Furthermore, as shown in FIG. 9, the member which has the 2nd light ray direction control means 4 of the 2nd sheet | seat was arrange | positioned on it. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the second light beam direction control means 4 in a direction substantially parallel to each other.
The evaluation results are shown in Table 1. Two second light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially parallel are combined, and diffused between the linear light source and the second light beam direction control means. In combination with the light diffusing plate (P-1) having the means, the measured luminance is lowered, which is not preferable as a lighting device. Further, moire was generated due to interference with the arrangement period of the convex portions of the two second light beam direction control means.

(Comparative Example 5)
First, the diffusing means 2 (light diffusing plate) (P-1) obtained above is arranged on the light exit surface side of the backlight, and the diffusing means 5 (light diffusing sheet; The product name “Opulse” BS-042) manufactured by Wa Corporation was superposed.
Next, as shown in FIG. 10, the second light direction control means 4 was disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion sheet 5 in a direction that is substantially parallel.
Furthermore, as shown in FIG. 10, the member which has the 1st light direction control means 3 was arrange | positioned on it. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube as the linear light source 1 and the convex lens ridge line are installed on the second light beam direction control means 4 in a direction substantially orthogonal to each other.
The evaluation results are shown in Table 1. The first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and the second arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially parallel. When combined with a light diffusing plate (P-1) having a light diffusing means between the linear light source and the first light directional control means, the light direction controlling member is combined so as to be opposite to the embodiment, The half-value angle was narrow, which was not preferable as a lighting device.

(Comparative Example 6)
The diffusing means 2 (light diffusing plate) (P-1) obtained above was arranged on the light exit surface side of the backlight.
Next, as shown in FIG. 11, the second light direction control means 4 was disposed thereon. As the second light direction control means 4, a member (B-1) having a light direction control means on which a convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube, which is the linear light source 1, and the convex lens ridge line are installed on the light diffusion plate 2 (P-1) in a direction substantially parallel to each other.
Furthermore, as shown in FIG. 11, the member which has the 1st light direction control means 3 was arrange | positioned on it. As the first light direction control means 3, the member (B-1) having the light direction control means on which the convex lens is formed is directed so that the surface on which the convex lens is formed is opposite to the linear light source 1 side. The longitudinal direction of the cold-cathode tube as the linear light source 1 and the convex lens ridge line are installed on the second light beam direction control means 4 in a direction substantially orthogonal to each other.
The evaluation results are shown in Table 1. The first light beam direction control means arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially orthogonal to each other, and the second arranged in a direction in which the longitudinal direction of the linear light source and the convex lens ridge line are substantially parallel. When combined with a light diffusing plate (P-1) having a light diffusing means between the linear light source and the first light directional control means, the light direction controlling member is combined so as to be opposite to the embodiment, The half-value angle was narrow, which was not preferable as a lighting device.

(Comparative Example 7)
The diffusing means 2 (light diffusing plate) (P-1) obtained above is arranged on the light exit surface side of the backlight, and the diffusing means 5 (light diffusing sheet; The product name “Opulse” BS-042) manufactured by the company was overlaid.
Next, as shown in FIG. 12, the first light beam direction control means 3 was disposed thereon. As the first light direction control means 3, a prism sheet (trade name “BEFIII-10T” manufactured by 3M Corporation) is placed on the prism sheet so that the surface on which the prism is formed is opposite to the linear light source 1 side. The light source 1 was installed in a direction in which the longitudinal direction of the cold cathode tube and the convex lens ridge line are substantially orthogonal. Furthermore, as shown in FIG. 12, the second light direction control means 4 is arranged thereon. As the second light direction control means 4, a prism sheet (trade name “BEFIII-10T” manufactured by 3M Co., Ltd.) is faced opposite to the linear light source 1 side, and the first direction control means 3. The longitudinal direction of the cold-cathode tube which is the linear light source 1 and the convex lens ridge line are installed in a direction substantially parallel to the top.
The evaluation results are shown in Table 1. First light direction control means disposed in a direction in which the longitudinal direction of the linear light source and the prism ridge line are substantially orthogonal to each other, and a second light direction control member disposed in a direction in which the longitudinal direction of the linear light source and the prism ridge line are substantially parallel to each other. When combined with a light diffusing plate (P-1) having a diffusing means between the linear light source and the first light direction control means, the measured luminance was a very high value, but the half-value angle Was very narrow and was not preferable as a lighting device.

(Comparative Example 8)
The diffusing means 2 (light diffusing plate) (P-1) obtained above is arranged on the light exit surface side of the backlight, and as shown in FIG. 13, the diffusing means 5 (light diffusing sheet; Three sheets of product name “Opulse” BS-042) manufactured by the company were superposed.
The evaluation results are shown in Table 1. When the first light direction control means and the second light direction control member were not used, the measured luminance was very low, which was not preferable as a lighting device.

Claims (9)

A substantially rectangular parallelepiped lighting device having a width, a height, and a thickness perpendicular to each other,
The width, height and thickness values are larger in this order,
A linear light source, a first light direction control means, a second light direction control means, toward the thickness direction emission side,
In this order,
A plurality of the linear light sources are arranged in parallel over the entire area,
Each of the first light direction control means and the second light direction control means comprises a plurality of bowl-shaped convex portions,
The first light direction control means controls the light direction along the width direction of the light from the linear light source and directs it to the second light direction control means.
The second light direction control means controls the light direction from the first light direction control means along the height direction, and returns a part of the light toward the first light direction control means. A lighting device characterized by the above.   2. The illumination device according to claim 1, further comprising a diffusing unit between the linear light source and the first light direction control unit.   3. The lighting device according to claim 1, wherein the first light beam direction control unit and the second light beam direction control unit have substantially the same cross-sectional shapes perpendicular to the longitudinal direction of the ridge-shaped projections.   The lighting device according to claim 2, wherein the diffusing unit is provided on a sheet-like member that is integral with the first light beam direction control unit. The lighting device according to claim 2, wherein the diffusing unit is provided on a sheet-like member different from the first light direction control unit.   The lighting device according to claim 2, wherein the diffusing means is fine particles dispersed in and / or on the surface of the sheet-like member.   The lighting device according to claim 2, wherein the diffusing unit has a fine uneven shape provided on a surface of the sheet-like member.   2. The illumination according to claim 1, wherein the plurality of linear light sources are arranged so as to be parallel to the width direction of the lighting device and to extend over substantially the entire width direction, and are arranged along the height direction. apparatus.   9. The image display device according to claim 1, further comprising: a transmissive display element that covers the surface on the side where the second light direction control means is provided. .

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